I - h B *r i ■?> ■ SAVAGE L l D K.AK. I OF THE ILN I V E R.5 ITY Of ILLINOIS 622. OS C63c9 The person charging this material is re- sponsible for its return on or before the Latest Date stamped below. Theft, mutilation, and underlining of books are reasons for disciplinary action and may result in dismissal from the University. University of Illinois Library L161— 0-1096 ' THE T. E, SAVAGE. COAL^METAL MINERS’ POCKETBOOK OF . PRINCIPLES, RULES, FORMULAS, AND TABLES. SPECIALLY COMPILED AND PREPARED FOR THE CONVENIENT USE OF MINE OFFICIALS, MINING ENGINEERS, AND STUDENTS PREPAR- ING THEMSELVES FOR CERTIFICATES OF COMPETENCY AS MINE INSPECTORS OR MINE FOREMEN. NINTH EDITION: REVISED AND ENLARGED, WITH ORIGINAL MATTER. “Though index learning turns no student pale, It grasps the Eel ol Science by the tail.” Pope. SCRANTON, PA.: INTERNATIONAL TEXTBOOK COMPANY. 1907 . Copyright, 1890 , 1893 , 1900 , BY Th,e Colliery Engineer Company. Copyright, 1901 , 1905 , BY International Textbook Company. Entered at Stationers’ Hall, London, All Rights Reserved. PRINTED BY International textbook Company, Scranton, pa., U. S. A. £2 ? T) D e.6?c < ? o eg kn ' Xs Preface to Ninth Edition. In this edition, the principal changes are in the section on wire rope, which has been greatly enlarged by the addition of material treating on cableways, tramways, transmission of \ power by wire rope, and wire-rope calculations. A glossary of ~ wire-rope terms has been added which has been checked up by the leading wire-rope makers of the United States, and therefore represents the latest practice. A number of changes have been made in this and previous editions, based on suggestions of users of the Pocketbook. We will appreciate any notice of errors or omissions so that future editions may be made as complete and accurate as possible. 4 C* vs 3 7, SquMes^ OuDes, Square and Cube Roots, Circumferences, Areas, and Reciprocal^ Horn 1 to 1,000, 545; Diameters, Circumferences, and Areas, ** w 100, 561. Glossary of Mining Terms.—565* COAL AND METAL MINERS’ POCKETBOOK. WEIGHTS AND MEASURES. THE METRIC SYSTEM. Since the metric system is the adopted system in many countries, and as it is almost universally used in connection with scientific work, a brief description of it is here given as preliminary to the following tables of weights and measures. The metric system has three principal units: 1. The meter , or unit of length , supposed to be the one ten-millionth part of the distance from the equator to the pole on the meridian of longitude passing through the city of Paris. Its actual value is 39.370432 in., the stand- ard authorized by the United States Government being 39.37 in. According to this standard, 1 yd. = meter. OjUOl 2. The gram , or unit of weight , is the weight of a cubic centimeter of dis- tilled water at 4° centigrade and 776 millimeters of atmospheric measure. The kilogram (Kg.) = 1,000 grams = 2.2046 lb., is the ordinary unit of weight corresponding to the English pound. According to the United States Gov- ernment regulations, 1 lb. avoirdupois = 1 2.2046 kilogram. 3. The liter , or unit of liquid volume , is the volume of 1,000 cubic centi- meters of distilled water at 4° centigrade and 776 millimeters pressure. Multiples of these units are obtained by prefixing to the names of the printed units the Greek words deka (10), hekto (100), kilo (1,000). The sub- multiples or divisions are obtained by prefixing the Latin words deci ( T V), centi ( T fo), and milli (^W)- The abbreviations of these several units as given in the following tables are those commonly used. The kilogram-meter is the work done in raising 1 kg. through a height of 1 m., and equals 7.233 ft.-lb. One metric horsepower (force de cheval or cheval vapeur) equals .98633 English horsepower. TROY WEIGHT. 24 grains = 1 pennyweight. 20 pennyweights = 1 ounce = 480 grains. 12 ounces = 1 pound = 5,760 grains = 240 pennyweights. In troy, apothecaries’, and avoirdupois weights, the grains are the same. APOTHECARIES’ WEIGHT. 20 grains = 1 scruple. 3 scruples = 1 dram = 60 grains. 8 drams = 1 ounce = 480 grains = 24 scruples. 12 ounces = 1 pound = 5,760 grains =,288 scruples = 96 drams. 2 WEIGHTS AND MEASURES. AVOIRDUPOIS WEIGHT. 27.34375 grains 16 drams 16 ounces 28 pounds 4 quarters = 1 dram. = 1 ounce = 1 pound = 1 quarter = 1 hundredweight 20 hundredweight = 1 ton 1 stone 1 quintal 1 “ short ton ” 1 “long ton ” 1 ounce troy or apothecaries’ = 1.09714 1 pound troy or apothecaries’ = .82286 1 ounce avoirdupois = .911458 1 pound avoirdupois = 1.21528 = 437i grains. = 7,000 grains = 256 drams. = 448 ounces. = 112 pounds. = 2,240 pounds. = 14 pounds. = 100 pounds. = 2,000 pounds. = 2,240 pounds, avoirdupois ounces, avoirdupois pound, troy or apothecaries’ ounce, troy or apothecaries’ pounds. 10 milligrams (mg.) 10 centigrams 10 decigrams 10 grams 10 decagrams 10 hectograms 10 kilograms 10 myriagrams 10 quintals METRIC WEIGHT. = 1 centigram (eg.) = 1 decigram (dg.) = 1 gram (g.) = 1 decagram (Dg.) = 1 hectogram (Hg.) = 1 kilogram (Kg.) = 1 myriagram (Mg.) = 1 quintal (Q.) = 1 tonneau, millier, or tc = .15432 grain. = 1.5432 grains. = 15.432 grains. = .0220461b. avoir. = .22046 lb. avoir. == 2.2046 lb. avoir. = 22.046 lb. avoir. = 220.46 lb. avoir. = 2,204 lb. avoir. MEASURES OF LENGTH. AMERICAN AND BRITISH. 12 inches = 1 foot. 3 feet = 1 yard = 36 in. 6 feet = 1 fathom = 2 yd. = 72 in. 66 feet = 1 chain *= 11 fath. = 22 yd. = 792 in. 10 chains = 1 furlong = 110 fath. = 220 yd. = 660 ft. = 7,620 in. 8 furlongs = 1 mile = 80 chains = 880 fath. = 1,760 yd. = 5,280 ft. = A nautical mile, or knot = 1.15136 statute miles. [63,360 in. A league = 3 nautical miles. *The chain of 66 ft. is practically obsolete. Chains of 50 or 100 ft. are now used exclusively by American surveyors. To Reduce Inches to Decimals of a Foot.— Divide the number of inches by 12. Thus, 7 in. = 7 -f- 12, or .58333 ft. To reduce fractions of inches to deci- mals of a foot, divide the fraction hv 12, and then divide the numerator of the quotient by the denominator. Thus, f in. = | -s- 12 = g 3 g . g 3 g — .0313 ft. The annexed scale shows on one side, proportionately reduced, a scale of tenths. On the other, a scale of twelfths, corresponding to inches. To reduce inches to decimal parts of a foot, find the number of inches and TENTHS OF A FOOT O 1 3 I 4 5 6 7 8 9 10 1.1.1-U yi, i.i.i .i. i,i.i ,1 ,i ,i ,i ,i J J uJ rnr 5 t j , 'i i jr r i f f r ' ! 1 ‘ 1 [ 7 S S H 1 l • i ' ' » I | 1 i • | ' • ■ i ■ ' 1 | ) 10 11 12 LSTCHUS fractional parts thereof on the side marked “inches.” Opposite, on the scale of tenths, will be found the decimal part of a foot. Thus, if we want to find the decimal part of a foot represented by 7£ inches, we find the mark corresponding to 7£ inches on the side marked “inches.” Opposite this mark we read 6 tenths, 2 hundredths, and 5 thousandths; or, expressed decimally, .625. ♦ MEASURES OF LENGTH. 3 DECIMALS OF A FOOT FOR EACH 1-32 OF AN INCH. Inch. 0" 1" 2" 3" 4" 5" 6" 7" 8" 9" 10" 11" 0 0 .0833 .1667 .2500 .3333 .4167 .5000 .5833 .6667 .7500 .8333 .9167 32 .0026 .0859 .1693 .2526 .3359 .4193 .5026 .5859 .6693 .7526 .8359 .9193 1^5 .0052 .0885 .1719 .2552 .3385 .4219 .5052 .5885 .6719 .7552 .8385 .9219 3% .0078 .0911 .1745 .2578 .3411 .4245 .5078 .5911 .6745 .7578 .8411 .9245 i .0104 .0937 .1771 .2604 .3437 .4271 .5104 .5937 .6771 .7604 .8437 .9271 3*2 .0130 .0964 .1797 .2630 .3464 .4297 .5130 .5964 .6797 .7630 .8464 .9297 t 3 s .0156 .0990 .1823 .2656 .3490 .4323 .5156 .5990 .6823 .7656 .8490 .9323 32 .0182 .1016 .1849 .2682 .3516 .4349 .5182 .6016 .6849 .7682 .8516 .9349 5 .0208 .1042 .1875 .2708 .3542 .4375 .5208 .6042 .6875 .7708 .8542 .9375 35 .0234 .1068 .1901 .2734 .3568 .4401 .5234 .6068 .6901 .7734 .8568 .9401 t 6 s .0260 .1094 .1927 .2760 .3594 .4427 .5260 .6094 .6927 .7760 .8594 .9427 33 .0286 .1120 .1953 .2786 .3620 .4453 .5286 .6120 .6953 .7786 .8620 .9453 i .0312 .1146 .1979 .2812 .3646 .4479 .5312 .6146 .6979 .7812 .8646 .9479 M .0339 .1172 .2005 .2839 .3672 .4505 .5339 .6172 .7005 .7839 .8672 .9505 I .0365 .1198 .2031 .2865 .3698 .4531 .5365 .6198 .7031 .7865 .8698 .9531 33 .0391 .1224 .2057 .2891 .3724 .4557 .5391 .6224 .7057 .7891 .8724 .9557 h .0417 .1250 .2083 .2917 .3750 .4583 .5417 .6250 .7083 .7917 .8750 .9583 e. .0443 .1276 .2109 .2943 .3776 .4609 .5443 .6276 .7109 .7943 .8776 .9609 .0469 .1302 .2135 .2969 .3802 .4635 .5469 .6302 .7135 .7969 .8802 .9635 if .0495 .1328 .2161 .2995 .3828 .4661 .5495 .6328 .7161 .7995 .8828 .9661 | .0521 .1354 .2188 .3021 .3854 .4688 .5521 .6354 .7188 .8021 .8854 .9688 flf .0547 .1380 .2214 .3047 .3880 .4714 .5547 .6380 .7214 .8047 -.8880 .9714 tt .0573 .1406 .2240 .3073 .3906 .4740 .5573 .6406 .7240 .8073 .8906 .9740 if .0599 .1432 .2266 .3099 .3932 .4766 .5599 .6432 .7266 .8099 .8932 .9766 £ .0625 .1458 .2292 .3125 .3958 .4792 .5625 .6458 .7292 .8125 .8958 .9792 If .0651 .1484 .2318 .3151 .3984 .4818 .5651 .6484 .7318 .8151 .8984 .9818 if .0677 .1510 .2344 .3177 .4010 .4844 .5677 .6510 .7344 .8177 .9010 .9844 if .0703 .1536 .2370 .3203 .4036 .4870 .5703 .6536 .7370 .8203 .9036 .9870 7 .0729 .1562 .2396 .3229 .4062 .4896 .5729 .6562 .7396 .8229 .9062 .9896 If .0755 .1589 .2422 .3255 .4089 .4922 .5755 .6589 .7422 .8255 .9089 .9922 .0781 .1615 .2448 .3281 .4115 .4948 .5781 .6615 .7448 .8281 .9115 .9948 33 .0807 .1641 .2474 .3307 .4141 .4974 .5807 .6641 .7474 .8307 .9141 .9974 METRIC SYSTEM. 10 millimeters (mm.) 10 centimeters 10 decimeters 10 meters 10 decameters 10 hectometers 10 kilometers = 1 centimeter (cm.) = = 1 decimeter (dm.) = = 1 meter (m.) = = 1 decameter (Dm.) = = 1 hectometer (flm.) = = 1 kilometer (Km.) = — 1 myriameter(Mm.) = .3937079 inch. 3.937079 inches. 3.2808992 feet. 10.9363 yards. 109.363 yards. .6213824 mile. 6.213824 miles. RUSSIAN. 12 inches = 1 foot = 1 American foot. 7 feet = 1 sachine, or sagene. 500 sachine = 1 verst = 3, 500 'feet. PRUSSIAN, DANISH, AND NORWEGIAN. 12 inches = 1 foot = 1.02972 American feet. 12 feet = 1 ruth = 12.35664 American feet. 2,000 ruths = 1 mile — 4.68+ American miles. AUSTRIAN. 12 inches = 1 foot = 1.03713 American feet. 6 feet = 1 klafter. 4,000 klafters = 1 mile = 4.71+ American miles, 4 WEIGHTS AND MEASURES. SWEDISH. 12 inches = 1 foot = .97410 American foot. 6 feet = 1 fathom. 6,000 fathoms = 1 mile = 6.64+ American miles. CHINESE. 1 chih = 1-054 American feet. 10 chih = 1 chang = 10.54 American feet. 180 chang = 1 li = 1,897 American feet. MEASURES OF AREA. 144 sq. inches 9 sq. feet 30i sq. yards 40 perches 4 roods 640 acres AMERICAN AND BRITISH. 3 square foot. 1 square yard = 1 perch = 1 rood = 1 acre = 1 square mile. 1,296 sq. in. 272i sq. ft. 1,210 sq. vd. = 10,890 sq. ft. 160 perches = 4,640 sq. yd. = 43,560 sq. ft. TABLE FOR REDUCING SQUARE FEET TO ACRES. Square Feet. Acres. Square Feet. Acres. 1 Square Feet. 1 Acres. Square Feet. Acres. 100,000,000 90.000. 000 80.000. 000 70.000. 000 60.000. 000 50.000. 000 40.000. 000 30.000. 000 20.000. 000 10,000,000 2,295.684 2,066.116 1,836.547 1,606.979 1,377.410 1,147.842 918.274 688.705 459.137 229.568 900,000 800,000 700.000 600.000 500,000 400.000 300.000 200.000 100,000 20.661 18.365 16.070 13.774 11.478 9.183 6.887 4.591 2.296 9.000 8.000 7.000 6.000 5.000 4.000 3.000 2,000 1,000 .207 .184 .161 .138 .115 .092 .069 .046 .023 90 80 70 60 50 40 30 20 10 .0021 .0018 .0016 .0014 .0011 .0009 .0007 .0005 .0002 9.000. 000 8.000. 000 7.000. 000 6.000. 000 5.000,000 4.000. 000 3.000. 000 2,000,000 1,000,000 206.612 183.655 160.698 137.741 114.784 91.827 68.870 45.914 22.957 90.000 80.000 70.000 60,000 50.000 40.000 30.000 20.000 10,000 2.066 1.836 1.607 1.377 1.148 .918 .689 .459 .230 900 800 700 600 500 400 300 200 100 .021 .018 .016 .014 .011 .009 .007 .005 .0023 9 8 7 6 , 5 4 3 2 1 .00021 .00018 .00016 .00014 .00011 .00009 .00007 .00005 .00002 METRIC SYSTEM. 1 square millimeter (sq. mm.) = 1 square centimeter (sq. cm.) 1 square decimeter (sq. dm.) -~ 1 square meter, or centare (m. 1 2 or sq. m.) — 1 square decameter, or are (sq. Dm.) 1 hectare (ha. ) 1 square kilometer (sq. Km.) 1 square myriameter (sq. Mm.) .001550 sq. in. .155003 sq. in. 15.5003 sq. in. 10.764101 sq. ft. .024711 acre. 2.47110 acres. 247.110 acres. 38.61090 sq. mi. MEASURES OF VOLUME. 5 MEASURES OF VOLUME. AMERICAN AND BRITISH. 1,728 cubic inches = 1 cubic foot. 27 cubic feet = 1 cubic yard. A cord of wood = 128 cu. ft., or a pile of wood 8 ft. long, 4 ft. wide, and 4 ft. high = 1 cord. A perch of masonry contains 24f cu. ft.; but in practice it is taken as 25 cu. ft. A ton (2,240 lb.) of Pennsylvania anthracite, when broken for domestic use, occupies about 42 cu. ft. of space; bituminous coal, about 46 cu. ft.; and coke, about 88 cu. ft. A bushel of coal is 80 lb. in Kentucky, Illinois, and Missouri, 76 lb. in Pennsylvania, 70 fb. in Indiana, and 76 lb. in Montana. METRIC SYSTEM. 1 milliliter, or cu. centimeter (cc. or cm. 3 ) 1 centiliter (cl.) 1 deciliter (dl. or dl. 3 ) 1 liter, or cu. decimeter (1.) 1 decaliter, or centistere (Dl. or dal.) 1 hectoliter, or decistere (HI.) 1 kiloliter, or cu. meter, or stere (Kl. or cm. 3 ) 1 myrialiter, or decastere (Ml.) .0610254 cu. in. .610254 cu. in. 6.10254 cu. in. 61.0254 cu. in. .353156 cu. ft. 3.53156 cu. ft. 35.3156 cu. ft. 353.156 cu. ft. 4 gills 2 pints 4 quarts 3H gallons 63 gallons 2 hogsheads 2 pipes LIQUID MEASURE (u. S.). 1 pint 1 quart 1 gallon 1. barrel 1 hogshead. 1 pipe. 1 tun. 16 liquid oz. 8 gills = 28.876 cu. in. = 57.75 cu. in. 32 gills = 8 pints = 231 7,276i cu. in. = 4.21 cu. in. cu. ft. A box 19f in. on each side contains 1 barrel. 1 cu. ft. — 7.48 gallons. DRY MEASURE (u. S.). 2 pints = 1 quart = 67.2006 cu. in. = 1.16365 liquid qt. 4 quarts = 1 gallon = 268.8025 cu. in. = 1.16365 liquid gal. 2 gallons = 1 peck = 8 quarts * = 537.6050 cu. in. 4 pecks = 1 bushel = 64 pints = 32 quarts = 8 gal. = 2,150.42 cu. in. BRITISH IMPERIAL MEASURE, BOTH LIQUID AND DRY. 4 gills = 1 pint = 34.6592 cu. in. 2 pints = 1 quart = 69.3185 cu. in. 4 quarts = 1 gallon = 277.274 cu. in. 8 quarts = 1 peck = 554.548 cu. in. 4 pecks = 1 bushel — 2,218.192 cu. in. The standard U. S. bushel is the Winchester bushel, which is in cylinder form, 18£ inches diameter and 8 inches deep, and contains 2,150.42 cubic inches. The British Imperial bushel is based on the Imperial gallon and con- tains 8 such gallons, or 2,218.192 cubic inches = 1.2837 cubic feet. Capacity of a cylinder in U. S. gallons = square of diameter in inches X height in inches X .0034 (accurate within 1 part in 100,000). Capacity of a cylinder in U. S. bushels = square of diameter in inches >< height in inches X .0003652. 6 WEIGHTS AND MEASURES. CONTENTS OF CYLINDERS OR PIPES FOR 1 FOOT IN LENGTH, The contents of pipes or cylinders in gallons or pounds are to each other as the squares of their diameters. Thus, a pipe 9 ft. in diameter will contain 9 times as much as a 3' pipe, or 4 times as much as a 4k' pipe. Diameters in Inches. 1 Diam. in Inches. Diameter in Decimals of a Foot. Gallons of 231 Cu.In. (U. S. Stand- ard.) Weight of Water in Lb. in 1 Ft. of Length. Diam. j in | Inches. 1 Diameter in Decimals ' of a Foot. | 1 - ! Gallons of 231 Cu. In. (U. S. Stand- ard.) Weight of Water in Lb. in 1 Ft. of Length. •1_ .0208 .0025 .02122 5 .4167 1.020 8.488 l .0417 .0102 .08488 5i .4583 1.234 10.270 | .0625 .0230 .19098 6 .5000 1.469 12.223 1 .0833 .0408 .33952 6£ .5417 1.724 14.345 li .1042 .0638 .53050 7 .5833 1.999 16.636 H .1250 .0918 .76392 n .6250 2.295 19.098 H .1458 .1249 1.0398 8 .6667 2.611 21.729 2 .1667 .1632 1.3581 8i .7083 2.948 24.530 2i .1875 .2066 1.7188 9 .7500 3.305 27.501 2i .2083 .2550 2.1220 9i .7917 3.682 30.641 2f .2292 .3085 2.5676 10 .8333 4.080 33.952 3 .2500 .3672 3.0557 10i .8750 4.498 37.432 3i .2917 .4998 4.1591 11 .9167 4.937 41.082 4 .3333 .6528 5.4323 1H .9583 5.396 44.901 4i .3750 .8263 6.8750 12 1.0000 5.875 48.891 Diameters in Feet. li 1.25 9.18 76.392 10 10.00 587.6 4,889.12 li 1.50 13.22 110.00 10i 10.50 647.7 5,404.24 If 1.75 17.99 149.73 11 11.00 710.9 5,915.84 2 2.00 23.50 195.56 1H 11.50 777.0 6,485.72 2t 2.25 29.74 247.51 12 846.1 7,040.00 2k 2.50 36.72 305.57 13 992.8 8,710.00 2f 2.75 44.43 369.74 14 1,152.0 10,096.00 3 3.00 52.88 440.00 15 1,322.0 11,000.50 31 3.25 65.28 544.37 16 1,504.0 12,516.00 °4 3k 3.50 71.97 631.00 17 1,698.0 14,166.00 St 3.75 82.62 687.53 18 1,904.0 15,841.00 4 4.00 94.0 782.24 19 2,121.0 17,691.00 4i 4.25 106.1 885.40 20 2,350.0 19,556.50 4 i 4.50 119.0 990.04 21 2,591.0 21,617.00 4f 4.75 132.5 1,105.71 22 2,844.0 23,663.00 5 5.00 146.9 1,222.28 23 3,108.0 25,943.00 5£ 5.25 161.9 1,351.06 24 3,384.0 28,160.00 5k 5.50 177.7 1,478.96 25 3.672.0 30.557.00 5£ 5.75 194.3 1.621.43 26 3,971.0 34,840.00 6 6.00 211.5 1,760.00 27 t 4,283.0 35,641.00 6i 6.25 229.5 1,915.18 28 4,606.0 40,384.00 6| 6.50 248.2 2,177.48 29 4,941.0 41,117.00 6| 6.75 267.7 2,233.96 30 5,288.0 44.002.00 7 7.00 287.9 2,524.00 31 5,646.0 46,984.00 7k 7.50 330.5 2,750.12 32 6,017.0 50,064.00 8 8.00 376.0 3,128.96 33 6,398.0 53,242.00 8£ 8.50 424.5 3,541.60 34 6,792.0 56,664.00 9 9.00 475.9 3,960.16 35 7.197.0 59.891.50 9i 9.50 530.2 1 1,122.84 36 | 7.61 1.0 1 63.36^.00 WEIGHTS AND MEASURES. 7 MEXICAN, CENTRAL AMERICAN, AND SOUTH AMERICAN WEIGHTS AND MEASURES. The following table gives weights and measures in commercial use in Mex- ico and the republics of Central and South America, and their equivalents in the United States. Published by the Bureau of the American Republics. Denomination. Where Used. U. S. Equivalents. Arobe ..." Paraguay 25 pounds. Arroba (dry) Argentine Republic 25.3175 pounds. Arroba (dry) Brazil 32.38 pounds. Arroba (dry) Cuba 25.3664 pounds. Arroba (dry) Venezuela 25.4024 pounds. Arroba (liquid) ... Cuba and Venezuela 4.263 gallons. Barril > Argentine Republic and Mexico 20.0787 gallons. Carga Mexico and Salvador 300 pounds. Centavo Central America 4.2631 gallons. Cuadra Argentine Republic 4.2 acres. Cuadra Paraguay 78.9 yards. Cuadra (square)... Paraguav 8.077 square feet. Cuadra Uruguay *2 6 A OTPS ( 71 PS Fanega (dry) Cen tral" America Clvi. v/O \ IlvCli 1 V J « 1.5745 bushels. Fanega (dry) Chile 2.575 bushels. Fanega (dry) Cuba 1.599 bushels. Fanega (dry) Mexico 1.54728 bushels. Fanega (dry) Uruguay (double) 7.776 bushels. Fanega (dry) Uruguay (single) 3.888 bushels. Fanega (dry) Venezuela 1.599 bushels. Frasco Argentine Republic 2.5096 quarts. Frasco Mexico 2.5 quarts. League (land)...'.... Paraguay 4,633 acres. Libra Argentine Republic 1.0127 pounds. Libra Central America 1.043 pounds. Libra Chile 1.014 pounds. Libra Cuba 1.0161 pounds. Libra Mexico 1.01465 pounds. Libra Peru 1.0143 pounds. Libra Uruguay 1.0143 pounds. Libra Venezuela 1.0161 pounds. Livre Guiana 1.0791 pounds. Manzana Costa Rica If acres. Marc Bolivia „ .507 pound. Pie Argentine Republic .9478 foot. Quintal Argentine Republic 101.42 pounds. Quintal Brazil 130.06 pounds. Quintal Chile, Mexico, and Peru 101.61 pounds. Quintal Paraguay 100 pounds. Vara Argentine Republic 34.1208 inches. Vara Central America 38.874 inches. Vara Chile and Peru 33.367 inches. Vara Cuba 33.384 inches. Vara Mexico 33 inches. Vara Paraguay 34 inches. Vara Venezuela 33.384 inches. CONVERSION TABLES. ( United States Coast and Geodetic Survey. ) The method of using the following tables for converting United States weights and measures into metric weights and measures will be understood by the following example: Find the number of kilometers in 125 miles. From column “ Miles to Kilometers,” 1 mile = 1.60935 kilometers, or 100 miles = 160.935 kilometers; 2 miles = 3.21869 kilometers, or 20 miles — 32.1869 kilometers; and 5 miles •= 8.04674 kilometers. Hence, 125 miles = 160.935 -+• 32.1869 + 8.04674 = 201.16864 kilometers, 8 WEIGHTS AND MEASURES. CUSTOMARY TO METRIC. Linear. Capacity. i to © © a to © © S 3 © © l 1 to Vh © to s © 03 © SB aa W is . « 03 tO a s csj © Ss S3 S fee 2 o . l sg 3 8a 3 © r* sga OS 3 . “ 8 15 © 5.-S O’ o •M . to to *3 ^ o 1 2 3 4 5 6 7 8 9 25.4 50.8 76.2 101.6 127.0 152.4 177.8 203.2 228.6 0.304801 0.609601 0.914402 1.219202 1.524003 1.828804 2.133604 2.438405 2.743205 ).914402 L. 828804 >.743205 3.657607 4.572009 3.486411 5.400813 7.315215 8.229616 1.60935 1 3.21869 2 4.82804 3 6.43739 4 8.04674 5 9.65608 6 11.26543 7 12.87478 8 14.48412 9 3.70 7.39 11.09 14.79 18.48 22.18 • 25.88 29.57 33.27 29.57 59.15 88.72 118.29 147.87 177.44 207.02 236.59 266.16 0.94636 1.89272 2.83908 3.78543 4.73179 5.67815 6.62451 7.57087 8.51723 3.78543 . 7.57087 v ll. 35630 15.14174 18.92717 22.71261 26.49804 30.28348 34.06891 \ 1 2 3 4 5 6 7 8 9 Square. Weight. to © to « £<2 C®5) I— I P m © O’.S s- CO +3 =3 Q s C O cc g © B ' sfs Cj CC-rH co H to rrt 1 £ • ^ H 05 t- S S3 So® 00 si Sg 08 Sg SB to g3 II to *2 OB S B 4 © d £ © § c S co« 5 2 to a~i S3 “ c3 |ga to © . © cc s s SS ss 6.452 12.903 1 9.355 25.807 32.258 38.710 45.161 51.613 58.065 9.290 18.581 27.871 37.161 46.452 55.742 65.032 74.323 83.613 0.836 1.672 2.508 3.344 4.181 5.017 5.853 6.689 7.525 0.4047 : 0.8094 : 1.2141 : 1.6187 - 2.0234 2.4281 2.8328 3.2375 3.6422 1 64.7989 2 129.5978 3 194.3968 4 259.1957 5 323.9946 6 388.7935 7 453.5924 8 518.3914 9 583.1903 28.3495 56.6991 85.0486 113.3981 141.7476 170.0972 198.4467 226.7962 255.1457 0.45359 0.90719 1.36078 1.81437 2.26796 2.72156 3.17515 3.62874 4.08233 31.10348 62.20696 93.31044 124.41392 155.51740 186.62088 217.72437 248.82785 279.93133 Cubic. Miscellaneous. 1 1 © to §*•§1 t -1 S d n O (3 5 o ©3 to 2o% P* to ?o . © ©o © o o£ ** © OQ l's CC © PJ © WW 1 Gunter’s chain = 20.1168 meters. 1 sq. statute mile = 259.000 hectares. 1 fathom = 1-829 meters. 1 nautical mile = 1,853.25 meters. 1 ft. = .304801 meter 9.4840158 log. 1 avoir, pound = 453.5924277 gram . 15,432.35639 grains = 1 kilogram. 1 2 1 ( i ij . 16.387 5 32.774 i 49.161 [ 65.54< j 81.93( 5 98.321 1 114.711 3 131.09' d 147.48 1 .02832 t .05663 L .08495 ) .11327 3 .14158 3 .16990 3 .19822 7 .22654 4 .25485 0.765 1.529 2.294 3.058 3.823 4.587 5.352 6.116 6.881 0.35239 0.70479 1.05718 1.40957 1.76196 2.11436 2.46675 2.81914 3.17154 CONVERSION TABLES. 9 The method of using the following tables for converting metric weights and measures into United States weights and measures may he understood by the following example: . Find the number of yards in 86 meters. From column “ Meters to Yards,” 8 meters = 8.748889 yards, or 80 meters _ 87.48889 yards; and 6 meters — 6.561667 yards. Hence, 86 meters 87.48889 + 6.561667 = 94.050557 yards. METRIC TO CUSTOMARY. Capacity. fj -iS O £ eters to Yards. Kilometers to Miles. | £ 1 39.37 3.28083 1.093611 0.62137 2 78.74 6.56167 2.187222 1.24274 3 118.11 9.84250 3.280833 1.86411 4 157.48 13.12333 4.374444 2.48548 5 196.85 16.40417 5.468056 3.10685 6 236.22 19.68500 6.561667 3.72822 7 275.59 22.96583 7.655278 4.34959 8 314.96 26.24667 8.748889 4.97096 9 354.33 29.52750 9.842500 5.59233 Square. i »s •iH a greater than. < less than. □ square. □' square feet. □" square inches. O round. ( ) [ 1 | | , vincula , denoting that the numbers enclosed are to be taken together; as, (a + 6)c = 4 + 3X5 = 35. degrees, arc or thermometer, minutes or feet, seconds or inches. 30° 40' 4" is 30 degrees 40 minutes 4 seconds. is 4 feet 6 inches, accents to distinguish letters , as a', a", a'", ai, « 2 , a b , a c , read a sub 1, a sub b, etc. a 2 , a 3 a squared, a cubed. as = i Yofi, at = > / a 3 . sin a = the sine of a. log = logarithm, angle. L right angle. _|_ perpendicular to. sin sine. cos cosine. 4' 6" / // nt ARITHMETIC. 15 MATHEMATICAL SIGNS AND ABBREVIATIONS— {Continued). tan, or tang, tangent. sec secant. versin versed sine. cot cotangent. cosec cosecant. covers coversed sine. tt' pi, ratio of circumference of circle to diameter 3.14159. g acceleration due to gravity = (32.16 ft. per sec.). R, r radius. W, w weight. H. P. horsepower. I. H. P. indicated horsepower. B. H. P. brake horsepower. A. W. G. American wire gauge (Brown & Sharpe). B. W. G. Birmingham wire gauge. r. p. m., or rev.’ per min., revolutions per minute. A decimal point is a period (.) pre- fixed to a number to show that the number is less than unity (1); thus, .2 = •&; .35 = y 3 (fo> 5.75 = 5 yo%> or 5|. ARITHMETIC. To Cast the Nines Out of a Number.— Add together the digits, and find how many nines are contained in their sum. Reject these nines and set down the remainder to the right of the number. Example —Cast the nines out of 18.304. 18,304. /. Ans. To Prove Addition.— Cast the nines out of each row of figures added, and out of their sum. Add together the remainder and cast the nines from its sum If the remainder from this last process is equal to the remainder obtained from the sum of the numbers, the addition is correct. Example— Prove this addition: 2,1 4 3,5 6 8 2 8,560,391 5 1 0,7 0 3,9 5 9 7. Ans. To Prove Subtraction.— Add the remainder to the lesser number; their sum should equal the larger number. .. , , ... To Prove Multiplication. —Cast the nines out of multiplicand and multi- plier and multiplv the remainders together. Cast the nines out of the product, and the remainder should equal the remainder obtained by cast- ing the nines from the original product. Example.— Prove this multiplication: 3,542 X 6,196 = 21,946,232. 3,5 4 2 5 6,1 9 6 4 2 1,9 4 6,2 3 2 2. Ans. To Prove Division.— Subtract the remainder, if there be any, from the dividend, and divide what remains by the quotient. If the new quotient equals the old divisor, the work is right. Example.— Divide 31,046,835 by 56. 554,407p. Ans. . Proof.— Take 43 from 31,046,835, and divide the remainder, 31,046, /92, by Rule.— To square any number containing the fraction multiply the whole number by the next higher whole number , and add |. Example.— (8£)* 2 — 8 X 9 + i = 72£. COMMON FRACTIONS. A fraction is a part of a whole, as f, etc. „ The numerator of a fraction is the number that tells how many parts of a whole are taken. Thus, 2 is the numerator of § , as it shows that two of the three parts into which the whole is divided are taken. The denominator of a fraction is the number that shows into how. many parts the whole is divided. Thus, in the fraction §, the 3 is the denominator. A common denominator is a denominator common to two or more fractions. Thus 4 and f have common denominators; and again, 12 is a common de- nominator for I-, and £, as they each are respectively equal to T 2 5 , T5 , T or tV To Divide Common Fractions.— Invert the divisor, and multiply. Example. — Divide & by §. AXf = T25* Ans. To Reduce Compound Fractions to Simple Fractions.— Multiply the integer by the denominator of the fraction, add the numerator for the new numera- tor, and place it over the denominator. Example.— Reduce 5§ to a simple fraction. 5X3 + 2 = 17, or the numerator, and the fraction is therefore To Reduce Simple Fractions to Compound Fractions.— Divide the numerator by the denominator, and use the remainder as the numerator of the remain- ing fraction. Example.— Reduce - 6 # to a compound fraction. 9)64(7 6 3 Compound fraction = 7+ Ans. “I To Reduce Common Fractions to Decimal Fractions.— Annex ciphers to the numerator, and divide by the denominator, and point off as many decimal places in the quotient as there are ciphers annexed. Example.— Reduce A to a decimal fraction. 16 ) 9.0 000 (.5 6 25 Ans. Note.— Ciphers annexed to a deci- mal do not increase its value. 1.13 is the same as 1.1300. Every cipher placed between the first figure of a decimal and the decimal point divides the decimal by 10. Thus, .13 -r- 10 = .013, 80 100 96 40 32 80 80 Table of Fractions Reduced to Decimals. Si .015625 If .265625 if .515625 11 l .765625 3*2 .03125 52 .28125 If .53125 hi .78125 .046875 19 64 .296875 if .546875 6] 63 .796875 T 5 .0625 T6 .3125 is .5625 1 c Tt .8125 Si .078125 n .328125 ii .578125 6 1 63 .828125 .09375 ii .34375 if .59375 ! hi f .84375 £ .109375 if .359375 if .609375 11 .859375 .125 f .375 i .625 i .875 Si .140625 if .390625 u .640625 64 .890625 S2 .15625 if .40625 hi .65625 If .90625 ii .171875 if .421875 If .671875 IS .921875 T6 .1875 TS .4375 ii .6875 ft .9375 £f .203125 if .453125 If .703125 fc .953125 "52 .21875 it .46875 it .71875 hi .96875 if .234375 if .484375 if .734375 ii .984375 i .25 1 .5 f .75 l 1.0000 DECIMALS. Decimal fractions have for their denominators 10 or a power of 10, but the denominator is usually omitted. Thus, .1 = .01 = T |^; .001 = Tt ha} e ^c. To Add Decimals.— Place whole numbers under whole numbers, tenths under tenths, hundredths under hundredths, etc., and add, placing the deci- mal point in the sum directly under the points above. Thus, 1 9.6 3 1 7 .00 7 5 .6 3 1.0 6 1 7.9 3 4 2 DECIMALS. 17 To Subtract Decimals.— Arrange the figures as in 5.9 69 7 8 addition, and proceed as in simple subtraction. 3. 2 8 6 9 4 Thus 2.6 8 2 8 4 To Multiply Decimals.— Proceed as in ' £ ££ simple multiplication, pointing oft* as many decimal places in the result as 14 0 2 5 9 3 there are decimal places in both mul- 2 3 3 7 6 5 5 tiplicand and multiplier. Thus 0.2 4 7 7 9 1 4 3 To Divide Decimals.— Proceed as in simple division, and decimal places in the quotient as the number of decimal dend exceeds those in the divisor. (5 decimal places) (3 decimal places) (8 decimal places) point off as many places in the divi- Example 1 .— Divide 4.756 by 3.3. . 3.3 ) 4.7 5 6 0 0 ( 1.4 4 1 2 Ans. 33 145 1 ^ Example 2.— Divide .006 by 20 Too 2 0 ).0 0 60 (.0 0 0 3. Ans. —40 — $-° 33 70 66 4 U 0TE it has been said before that algebra is a shorthand arithmetic. Before proceeding further with the various methods of arithmetic, the principles of algebra will be stated, and, after the subsequent examples are worked out by arithmetical rules, an example will be given of the algebraic method of doing the same. In every example, we have known quantities from which we seek to find certain unknown ones. While there is no way of indicating these in arithmetic , we can readily do so in algebra , by placing the first letters of the alphabet as representatives of the known quantities (as a, b, c), and the last letters ( x , y, z) of the unknown ones. The signs m algebra are those just given for arithmetic. In addition to them, we can indicate multiplication by placing a period (.) between the quantities, as a.b (read a multiplied by b), or simply by placing the two letters together, as ab. We can indicate division as in common fractions, ^ being read a divided by b. To illustrate algebraic symbols, let l denote the length, b the breadth, and h the height of a mine car. If it be desired to divide the height into the product of the length and breadth, it is expressed as follows: lb h‘ When two or more letters are placed together, without anything between them, it is understood that the quantities represented by those letters should be multiplied together. If l represents 8 and b represents 4, then 4 and 8 are multiplied together; thus, 4 X 8 = 32. , ,, , ,,, If it be desired to divide the height into the sum of the length and breadth, it is expressed thus: l -}- b h '' The square of the length multiplied by the cube of the breadth, thus: l*b\ The square root of the length divided by the cube root of the breadth, thus: VT The square root of the difference of the length and breadth divided by the height, thus: V l — b 18 PROPORTION. SIMPLE PROPORTION, OR SINGLE RULE OF THREE. .A PJ 0 P° rti ? n is , expression of equality between equal ratios; thus, the ratio of 10 to 5 = the ratio of 4 to 2, and is expressed thus: 10 : 5 : : 4 : 2. There are four terms in proportion. The first and last are the extremes and the second and third are the means. Quantities are in proportion by alternation when antecedent is compared with antecedent and consequent with consequent. Thus, if 10 : 5 : : 4 : 2, then 10 ! 4 i ! 5 * 2. Quantities are in proportion by inversion when the antecedents are made consequents and the consequents antecedents. Thus, if 10 : 5 • • 4 • 2 then 5 : 10 : : 2 : 4. ’ In any proportion, the product of the means will equal the product of the extremes. Thus, if 10 : 5 : : 4 : 2, then 5X4-10X2. A mean proportional between two quantities equals the square root of their product. Thus, a mean proportional between 12 and 3 = the square root of 12 x 3, or o. If the two means and one extreme of a proportion are given, we find the other extreme by dividing the product of the means by the given extreme. 1° : : : 4 : ( )• then (4 X 5) -4- 10 = 2, and the proportion is 10 : 5 : : 4 : 2 ,. tt the two extremes and one mean are given, we find the other mean bv dividing the product of the extremes bv the given mean. Thus. 10 * M • • 4 • 2 then (10 X 2) 4- 4 = 5, and the proportion is 10 : 5 : : 4 : 2. ’ ' " ’ .Example.— I f6 men load 30 wagons of coal in a day, how many wagons will 10 men load? (They will evidently load more, so the second term of the proportion must be greater than the first.) 6 : 10 : : 30 : ( ); then, (10 X 30) 4- 6 = 50. Ans. COMPOUND PROPORTION, OR DOUBLE RULE OF THREE. Principles. 1. The product of the simple ratios of the first couplet equals the product of the simple ratios of the second couplet. T-hus, /4 : 12) . (5 : 10) = ± 7_ _ _5 6 (7 : 14 J (6 : 18/ 12 X 14 10 X 18‘ 2. The product of all the terms in the extremes equals the product of all the terms m the means. Thus, in J 4 : 121 (5 : 10) 17 : 14/ * ' 16 : 18/ we have 4 X 7 X 10 X 18 - 12 X 14 X 5 X 6. 3. Any term in either extreme equals the product of the means divided by the product of the other terms in the extremes. Thus, in the same proportion, we have 4 = 5 X 6 X 12 X 14 7X10X18 * 4. Any term in either mean equals the product of the extremes divided by the product of the other terms in the means. Thus, in J 4 : 12) . . (5 : 101 17 : 14/ ‘ * 16:18/ we have 5 = (4 X 7 X 10 X 18) 4- (6 X 12 X 14). Ru J?-— >• Put the required quantity for the first term and the similar known quantity for the second term , and form ratios with each pair of similar quantities for the second couplet , as if the result depended on each pair and the second term. II. the required term by dividing the product of the means by the product oj inejourtn terms. . S X / MP ^ E 1 * — If 4 men can earn $ 24 in 7 days, how much can 14 men earn in 12 days? = $144. Ans. The sum : $24 : : : 4 j . or> the sum = Example 2.— If 12 men in 35 days build a wall 140 rd. long, 6 ft. high, how 24 X 14 X 12 4X7 EVOLUTION. 19 many men can, in 40 days, build a wall of the same thickness 144 rd. long, 5 ft. high? 12:()=??4^^ = 9. Ans. f 40 : 35 ) 4 140 : 144 y : : l 6:5 J 40 X 140 X 6 INVOLUTION. To Square a Number.-— Multiply the number by itself. Thus, the square of 4 = 4 X 4, or 16. To Cube a Number.— Multiply the square of the humber by the number. Thus, the cube of 4 = 16 X 4 = 64. To Find the. Fourth Power of a Number.— Multiply the cube by the number. Thus,, the fourth power of 4 = 64 X 4 = 256. To Raise a Number to the Sixth Power. — Square its cube. To Raise a Number to the Twelfth Power.— Square its sixth power. (See logarithms for shorter method.) EVOLUTION. To Find the Square Root of a Number: Rule. — I. Separate the given number into periods of two figures each , beginning at the units place. II. Find the greatest number whose square is" contained in the period on the left; this will be the first figure in the root. Subtract the square of this figure from the period on the left , and to the remainder annex the next period to form a dividend. III. Divide this dividend , omitting the figure on the right , by double the part of the root already found, and annex the quotient to that part , and also to the divisor; then , multiply the divisor thus completed ' by the figure of the root last obtained , and subtract the product from the dividend. IV. If there are more periods to be brought down , continue the operation as before. Example.— Find the square root of 8 7'4 2'2 5 ( 9 3 5 Ans. 874,225. 8 1 18 31 TT41T 549 186 5 | 9325 9 3 25 OPERATION. 9 X 2 = 18. 18 into 64 goes 3 times, hence new divisor = 183. 93 X 2 = 186. 186 into 932 goes 5 times, hence new divisor = 1,865. (See logarithms for shorter method.) The square root of a fraction is found by extracting the square root of the numerator and denominator separately. Thus, the square root of ^ f . When decimals occur, the number is pointed off into periods both right and left from the decimal point, and there will be as many decimal places in the root as there are periods to the right of the decimal point in the number. Example 1.— Find the square root of 874.225. 8'7 4.2 2'5 ( 2 9.5 6+ 4 9i 4 7 4 441 Example 2.— Find the square root of .00874225. .0 0'8 7'4 2'2 5 (.0 9 3 5 81 18 3| " 590 29 25 7] 39 75W 35442 642 549 18 6 5| 93 25 9325 4 3 08+ To Find the Cube Root of a Number: Rule. — I. Separate the given number into periods of three figures each , beginning at the units place. II. Find the greatest number whose cube is contained in the period, on the left; this will be the first figure in the root. Subtract the cube of this figure from the period on the left , and to the remainder annex the next period to form a dividend • 20 PERCENTAGE. Ill Divide this dividend by the partial divisor , which is 3 times the square of the root aS found? considered as tens; the quotient is the second figure of the r °°\\l To the vartial divisor add 3 times the product of the second figure of the root by the firsf considered as tens , also the square of the second figure, the result willbe com piete divisor by the second figure of the root , and subtract the^oduct^J^dMdend. dolOTl , proceed™ before, using the part of the root already found, the same as the JM . figure t» thepremous process. Example.— Find the cube root of 12,812,904. operation. • j ^ . . 1 2,8 1 2,9 0 4 ( 2 3 4 Ans. 2 } = = 8 1st partial divisor, 3 X 20 2 = 3 X 20 X 3 = 1,2 0 0 180 4,812 3 2 = 9 4,1 6 7 1st complete divisor, 1,3 8 9 6 4 5,9 0 4 2d partial divisor, 3 X 230 2 == 3 X 230 X 4 = 1 5 8,7 0 0 2,7 6 0 6 4 5,9 0 4 42 = 16 2d complete divisor, 1 6 1,4 7 6 , The cube root of a fraction is found by extracting the cube root of the numerator and denominator separately. Thus, the cube root of 64 (See logarithms for shorter method.) PERCENTAGE. Percentage means by or on the hundred. Thus, 1 J> = xh = - 01 > plue“theratl e SSjS ft SSZSTgSSXZXA agebythe rate 68 ' Thus?!" ' 'the' rateVt^and thepwclnkg^sll^! thebase ™ ^dtbe D ^S« equals 115.80 -e- 1,930 = .06, or 6£ ARITHMETICAL PROGRESSION. sum of the terms 49. In any arithmetical progression, T pt f = first term; l = last, or nth term; d = common difference; n = number of terms; and s = their sum. , fA ^ The second term =/ + ( S-D* =/+ *. the fourth term -/+(4-l)d. and the nth term = /+( „_ 1)d . (1) From equation (1) we obtain , f=l±{n-l)d. (2) d== ^ITi „ ^ f 4-1 (3) (4) (5) GEOMETRICAL PROGRESSION, 21 Substituting the value of l from (1), «= 2 [2/+(w “" 1) 554 > 432 j< 2 — T y = $671,088.63i|. Ans. 22 LOGARITHMS. LOGARITHMS. USE OF LOGARITHMS. I nparithms are designed to diminish the labor of multiplication and divi- sion bv substituting in their stead addition and subtraction. A logarithm us the exponent of the power to which a fixed number, called the base, must be raised to produce a given number. The base of the common systein is 10, and as a logarithm is the exponent of the power to which the base must be raised in order to be equal to a given number, all numbers are to be regarded as powers of 10; hence, 100 = 1, we have logarithm of 1 = 0. 10 1 = io, we have logarithm of 10 = 1. 102 = ioo, we have logarithm of 100 = 2. 103 = i ooo, we have logarithm of 1,000 = 3. 104 = 10,000, we have logarithm of 10,000 = 4. The logarithms of numbers between 1 and 10 are less than unity, and are pxnressed as decimals. The logarithm of any number between 10 and 100 is moreXn 1 anTless than 2, hence it is equal to X plus a decimal. Between ^Thf^ in^ral'parfof a* logarithmls'tts ^clwraoteristio, the decimal part is ltS Example.— The log of 67.7 is 1.83059, the characteristic of this logarithm lS 1 Th^ charter illic of a logarithm is always 1 less than the number of whole ^es expressing that lumber and may ^ fher neg^i veorposvUve y 32 G M 72 J 2.4807608. 9 y Example 3.— 5 /-- log .677 1.830589 5 4.830589 v - 677 = 5 = 5 ' 5 + 5 1.9661178 m .9249+. GEOMETRY. PRINCIPLES OF GEOMETRY. 1. The sum of all the angles formed on one side of a straight line equals two right angles, or 180°. 2. The sum of all the angles formed around a point equals four right angies, or 360°. ,, ., .. . 3. When two straight lines intersect each other, the opposite or vertical angies are equal. . „ „ _ , 4. If two angles have their sides parallel, they are equal. 5. If two triangles have two sides, and the included angle of the one equal to two sides and the included angle of the other, they are equal in all their parts^ ^ r j an g^ es h ave two angles, and the included side of the one equal to two angles and the included side of the other, they are equal in all their Darts 7. ’ In any triangle, the greater side is opposite the greater angle, and the greater angle is opposite the greater side. . . , » 8. The sum of the lengths of any two sides of a triangle is greater than the length of the third side. . 9 In an isosceles triangle, the angles opposite the equal sides are equal 10. In any triangle, the sum of the three angles is equal to two right sniffles or 180^ ll/’lf two angles of a triangle are given, the third may be found by subtracting their sum from two right angles, or 180°. 12. A triangle must have at least two acute angles, and can have but one obtuse triangle! a perpendicular let fall from the apex to the base is shorter than either of the two other sides. GEOMETRY. 25 14. In any parallelogram, the opposite sides and angles are equal each to each. 15. The diagonals divide any paralellogram into two equal triangles. 16. The diagonals of a parallelogram bisect each other; that is, they divide each other into equal parts. 17. If the sides of a polygon be produced in the same direction, the sum of the exterior angles will equal four right angles. 18. The sum of the interior angles of a polygon is equal to twice as many right angles as the polygon has sides, less four right angles. Example.— The sum of the interior angles of a quadrilateral = (2X4) — 4 = 4 right angles. The sum of the interior angles of a pentagon = (2 X 5) — 4 = 6 right angles. The sum of the interior angles of a hexagon = (2 X 6) — 4 = 8 right angles. 19. In equiangular polygons, each interior angle equals the sum divided by the number of sides. 20. The square described on the hypotenuse of a right-angled triangle is equal to the sum of the squares described on the other two sides. Thus, in a right-angled triangle whose base is 20 ft. and altitude 10 ft., the square of the hypotenuse equals the square of 20 + the square of 10 , or 500. Then the hypotenuse equals the square root of 500, or 22.3607 ft. 21. Having the hypotenuse and one side of a right-angled triangle, the other side may be found by subtracting from the square of the hypotenuse the square of the other known side. The remainder will be the square of the required side. 22. Triangles that have an angle in each equal, are to each other as the product of the sides including those equal angles. 23. Similar triangles are to each other as the squares of their correspond- ing sides. 24. The perimeters of similar polygons are to each other as any two corresponding sides, and their areas are to each other as the squares of those sides. 25. The diameter of a circle is greater than any chord. 26. Any radius that is perpendicular to a chord, bisects the chord and the arc subtended by the chord. 27. Through three points not in the same line, a circumference may be made to pass. Directions— Draw two lines connecting the three points. Erect perpen- diculars from the centers of each of these two lines, and the point of inter- section of the perpendiculars will be the center of the circle. 28. The circumferences of circles are to each other as their radii, and their areas are to each other as the squares of their radii. Example 1 .— If the circumference of a circle is 62.83 in. and its radius is 10 in., what is the circumference of a circle whose radius is 15 in. ? 10 : 15 : : 62.83 : 94.245 in. Ans. Example 2— If a circle 6 in. in diameter has an area of 28.274 sq. in., what is the area of a circle 12 in. in diameter ? 32 : 6 2 : : 28.274 : 113.096 sq. in. Ans. PRACTICAL PROBLEMS IN GEOMETRICAL CONSTRUCTION. \E To Bisect a Given Straight Line AB . — From A and B as centers, with a radius greater than l one-half of A B, describe arcs intersecting at E A k B and F. Draw E F. It will bisect A B. C will 1° be the middle point, and ^Fwill be perpendic- ular to AB. The points ^and i^will be equi- distant from A, B, or C. From a Given Point C, Without a Straight Line AB, to Draw a Perpendicular to the Line.— From C as a center, with a radius sufficiently great, describe an arc cutting AB in points A and B; then from A and B as centers, with a radius greater than one-half of A B , describe two arcs cutting each other at Z>, and draw CD. C _E 26 GEOMETRY. A XD A+ 4 B At a Given Point C in a Straight Line AB, to Erect a Perpendicular to That Line.— Take the points A and B equally distant from C, and, with A and B as centers, and a radius greater than one-half of A B , describe two arcs cutting each other at D, and draw the line D C. At a Point i on a Given Straight Line A B, to Make an Angle Equal to a Given Angle Ei G. From F as a center, with any radius ± G, describe the arc EG. From A as a center, with the same radius, describe the arc CB\ then with a radius equal to the chord EG, describe an arc from £ as a center, cutting Oil at D, and draw A D To Bisect a Given Arc ACB.-With the same radii and the extremities A B as centers, descnbe arcs intersecting at D and E. The line D E bisects the arc at C. To Bisect an Angle A B C.-With any radius and R as a center, describe an arc cutting the sides at A and C With these points as centers, describe arcs of equal radius intersecting at D. The line B D is the bisector, and the LAB D = LB B C. & R Through a Given Point A to Draw a Straight Line Parallel to a Given Straight L |ne CD .— From A as a center, with a radius greater than the shortest distance from A to CD, describe an indefinite arc D E. From D as a center, with the same radius, describe the arc A Take D E equal to A F, and draw A B. To Bisect an Open Angle ( Method by L. L. Logan).— Let AB and CD be the sides of an open angle. With any point 0 as a cen- ter, describe a circle cutting the sides at e f a and h, and with e and/, and g and h as centers and any radius, describe arcs intersecting at k and l, respectively. Draw Ok and 01 and mn. With p and gas cen- ters, and any radius, describe arcs intersect- ing at R and S. The line drawn through is the required bisector. C ft 1 /' \ \ B To Find the Center of a Given Circumference or Arc. Take any three i>oints ,4, B.and C on the circumfer ence, and unite them by the lines A 5andJ C. Bisect these chords by the perpendiculars D 0 and E 0, their intersection is the center of the circle. GEOMETRY. 27 Through a Given Point P, to Draw a Tangent to a Given Circle.— 1 . If P be in the circumference: Find C the center of the circle, draw the radius CP , and draw D E perpendicular to C P. 2. If P be without the circle: Join P and the center of the circle. Bisect P C in D; with D as a center, and a radius D 0 , describe the cir- cumference intersecting the given circumference at A and B. From the intersections A and B, draw B P and A P. An acute angle having its vertex in the circumference and subtended by an arc is equal to one-half the central angle subtended by the same arc. Thus, the L A B C — w L. A O C. An acute angle included between a chord and a tangent is equal to one-half the central angle subtended by the chord. Thus, [_ ABC = £ l_ COB. If, from a point, two tangents be drawn to a circle, they will be equal, and their angle of intersection will be equal to the central angle subtended by the chord joining the two points of tangency. Thus, A B = AC. and c DAC = L BOC. To Divide a Straight Line Into Any Number of Equal Parts.— To divide the line AB into, say, 6 parts, draw the line A C from A, making any angle with A B; measure off 6 equal spaces on A C; draw 6 B , and from 1, 2, 3, U, 5 on A Cdraw parallels to 6 B. These divide A B as required into 6 equal parts. By a similar process a line may be divided into a number of unequal parts. Set off on A C divisions proportional to the required divisions, and draw the parallel lines as explained above. 23 MENSURATION. MENSURATION. MENSURATION OF SURFACES. PARALLELOGRAMS. A parallelogram is a four-sided figure whose opposite sides are parallel. 'sJtZista* and four right an- and opposite sides and oblique angles.) opposite sides equal.) gtes.) equal.) Tn Find the Area of Anv Parallelogram.— Multiply the length of any side by the length of a perpendicular line from that side to the oppositeone. Thus, 6 in ^he foregoing^ figures, the areas of the square are the length^B by the «o« To Find the Area of the Largest Square That May be Inscribed in a Circle. Snuare the radius of the circle, and multiply by 2. , . «■ «_. ^Tn Find the Side of the Largest Square That May be Inscribed in a Circle. Dhdde the Lmeter of the circle 4 1.41421, or multiply it by .707107. TRIANGLES. A triangle is a figure having three straight sides. Equilateral. ( Three equal sides.) Isosceles. ( Two equal sides.) Scalene. ( Three un- equal sides.) To Find the Area of. a Triangle.-Multiply its base by one-half the perpen- ^Tonndf^er^ndfcu^Height of an Equilateral Triangle.-Multiply the length *Nr&s tipiy the length of one of its sides by .658037. TRIANGLES. 29 To Find the Diameter of a Circle of Same Area as an Equilateral Triangle. Divide the length of one of its sides by 1.34677. The following rules apply to any triangle: Having Two Sides and the Included Angle, to Find the Area. — Multiply together the two sides and the natural sine of the included angle, and divide the product by 2. Or, by logarithms, add together the logarithms of the two sides and the logarithmic sine of the included angle, and from the sum subtract the logarithm of 2, and the result will be the logarithm of the area. Having Three Sides of a Triangle, to Find the Area.— Add the three sides together, divide the sum by 2; from the half sum, subtract each side sep- arately; multiply the half sum and the three remainders continuously together, and extract the square root of the product. Thus, if the triangle has three sides whose lengths are 30, 40, and 50 ft., then = 60. Then, subtracting from this 60 each side separately, we have: 60 — 30 = 30; 60 — 40 - 20; 60 - 50 = 10. Then, 60 X 30 X 20 X 10 = 360,000. The square root of 360,000 = 600 sq. ft., or area. Having the Three Sides of a Triangle, to Find Its Angles.— In the triangle A B C, let A B = 21 ft., B C = 17.25 ft., and A C = 32 ft. Draw B D per- pendicular to AC’, then, 32 : 21 + 17.25 = 21 — 17.25 AD - DC’, But Adding, Subtracting, AD — DC = 4.48 AD + DC = 32 2 AD — 36.48 AD = 18.24 2 DC = 27.52 DC = 13.76 cos A = = .86857, or A = 29° 42' 25.7". 13 76 cos 0 = Wm = * 79768 ’ or c = 370 5 ' 26.7". B = 180° — (A + C) = 1.80 — (29° 42' 25.7"+ 37° 5' 26.7") = 113° 12' 7.6". Having Two Sides and Included Angle, to Find Third Side and the Other Angles. In the triangle ABC, let A B = 19 ft., A C = 2P ft., and A = 36° 3' 29". Draw B D perpendicular to AC. BD = 19 X sin A = 19 X .58861 = 11.18 ft. A D = 19 X cos A = 19 X .80842 = 15.36 ft. D C = 23 — 15.36 = 7.64 ft. 11 18 Tan C = = 1.46335, or C = 55° 39' 10". B = 180 — (A + C) = 180 - (36° 3' 29" + 55° 39' 10") = 88° 17' 21". B C = B ? = - 11 ’ 18 = 13 54 ft „ . , - sin C .82562 ^naving One Side and the Two Adjacent Angles, to Find the Other Two Sides. The third angle equals 180° minus the sum of the other two angles. This third angle will be the one opposite the given side. Then the sine of the angle opposite the given side is to the given side as the sine of either of the other angles is to its opposite side. Thus, in the triangle ABC, let A = 60°, B 50° 700 ’ and the Side A B = 200 ft * Then the angle C = 180 °” ( 60 ° + 70 °) Then, sin 50° : 200 : : sin 60° : B C, and sin 50° : 200 : : sin 70° : A C. To Find the Area.— Either find the three sides as above, and follow rule already given, or multiply the natural sines of the two given $pgles togethgj •. 30 MENSURATION. Thpn ns the natural sine of the single angle is to the product of the sines of to riven ; ang “is the°squar^ 0 ffhe given side to twice the reqmred area, rrvmc «in r • sin A y sin B •: A B 1 : to twice the area of the triangle. The area of tny triangle is equal to half the area of a parallelogram having the same base and perpendicular height. trapezoids. A trapezoid has four straight sides, only two of which are parallel. F — ,Z> To Find the Area of a Trapezoid.-Add together the two parallel sides, and dl vide r by 2. Multiply the quotient by the perpendicular height. Thus, ABA CD X E F = area. TRAPEZIUMS. A trapezium has four sides, no two of which are parallel. To Find the Area of a Trapezium.— Divide the trape- zium into two triangles, and find the area ol each according to the rules given under the head ot “ Triangles.” Add together the areas of the two triangles, and the sum will equal the area of the trapezium. The sides and angles can be found m th mhemagon e ais a'nd the perpendiculars from them to the opposite angles are given, add together the two perpendiculars, multiply the sum by the ^The^m o^^^four 2 angles included in a trapezium always equals four right angles. POLYGONS. All figures bounded by more than four straight lines are called polygons. If all the sides and angles are equal, it is a regular polygon. If not, it is an The^sum o? the interior angles of any polyg B. W^hen havtT ttaL angli and two sides of the triangle A DB. * e find the third side r we haye the angles iBC and B A C. and the side C2> by Case 4. . SURVEYING. employ^ iXth are the S aAd me^ring pins, and Sometimes eert^n aeces- ^ Smenis. as clinometers or slope levels, dipping needles, etc., as » dl deviations from the practice of the form er. THE COMPASS. e=^SsSESS gs^^safiasssss should never be relied on. TO ADJUST THE COMPASS. _, , . Fir ^ r \yYins the bubbles into the center by the pressure of the The Levels.— First and theri turn the compass halfway hand on ddfarent JK^lPrunto' the ends of the tubes, it would Indicate around: should the ouDOies lower them, bv tightening the screws that^o^ en^ we^he^h^ * hose linder t ‘ he lower ends until by immediately tinder. i Tel ttie P i ate again, and repeat the &^mtion e tSmthe^nbbles will remain in the center during an entire revolution of Aecomi^. observing through the slits a fine hair or The sights may next betretea y , umb Sh , lllLld the hair appear on one S'Slt ”he dght^ mmi bfe adjusted by filing off its under surface on theade that following manner: Having the eye nearly in The needle ls^jnsted mine n - of the compass circle, with a small the same plane mth the ^adi l * ^ wire brin^ cue end of the needle in line splinter of d f^5onof the circle as the zero or 90° mark, and notice with any prominent divmon oi tne^ c ' h opposite side: if it does, if the other end fV^^?^^ e th d e e ^^if "ot. ben¥ the center pin by a? s s?.bSa ris ««■ .= MAGNETIC VARIATION . 39 circle; if any error is there manifested, the correction must be made in the center pin only, the needle being already straightened by the previous operation. „ , When again made to cut, it should be tried on the other quarters of the circle, and corrections made in the same manner until the error is entirely removed, and the needle will reverse in every point of the divided circle. TO USE THE COMPASS. In using the compass, the surveyor should keep the south end toward his person, and read the bearings from the north end of the needle. In the sur- veyor’s compass, he will observe that the position of the E and W letters on the face of the compass are reversed from their natural position, in order that the direction of the sight may be correctly read. The compass circle being graduated to half degrees, a little practice will enable the surveyor to read the bearings to quarters— estimating with his eye the space bisected by the point of the needle. The compass is usually divided into quadrants, and zero is placed at the north and south ends. 90° is placed at the E and W marks, and the gradua- tions run right and left from the zero marks to 90°. In reading the bearing, the surveyor will notice that if the sights are pointed in a N W direction, the north end of the needle, which always points approximately north, is to the right of the front sight or front end of the telescope, and, as the number of degrees is read from it, the letters marking the cardinal points of the compass read correctly. If the E, or east, mark were on the right side of the circle, a N W course would read N E. This same remark applies to all four quadrants. The compass should always be in a level position. MAGNETIC VARIATION. Magnetic declination or variation of the needle is the angle made by the magnetic meridian with the, true meridian or true north and south line. It is east or west according as the north end of the needle lies east or west of the true meridian. It is not constant, but changes from year to year, and, for this reason, in rerunning the lines of a tract of land, from field notes of some years’ standing, the surveyor makes an allowance in the bearing of every line by means of a ver- nier that is so graduated that 30 spaces on it equal 31 on the limb of the instrument, as shown in the figure. To Read the Vernier.— As the compass vernier is usually so made that there . are but 15 spaces on each side of the zero mark, it is read as follows: Note the degrees and half degrees on the limb of the instrument. If the space passed beyond the degree or half-degree mark by the zero mark on the vernier is less than one-half the space of half a degree on the limb, the number of minutes is, of course, less than 15, and must be read from the lower row of figures. If the space passed is greater than one-half the spacing on the limb, read the upper row of figures. The line on the vernier that exactly coincides with a line on the limb is the mark that denotes the number of minutes. If the index is moved to the right, read the minutes from the left half of the vernier; if moved to the left, read the right side of the vernier. To Turn Off the Variation.— Moving the vernier to either side, and with it, of course, the compass circle attached, set the compass to any variation by placing the instrument on some well-defined line of the old survey, and by turning the tangent screw (slow-motion screw) until the needle of the com- pass indicates the same bearing as that given in the old field notes of the original survey. Then screw up the clamping nut underneath the vernier and run all the other lines from the old field notes without further alteration. The reading of the vernier on the limb gives the amount of variation since the original survey was made. The accompanying man shows the general course and direction ofisogonic lines (those passing through points where the magnetic needle has the same 4C SURVEYING . declination), in all parts of the United States and Mexico for the year 1900. These lines are drawn full when compiled from reliable records, but dotted in other places. The declination is marked in degrees at each end of every alternate line, the sign + indicating a west declination, and the sign — an east declination. The yearly variation, or change of declination, for the period 1895-1900 is marked in numerous places on the map. The annual change in declination is given in minutes; a -l- sign signifies increasing west or decreasing east declination, a — sign the reverse motion. Stations to the right of the agonic curve, or curve of no declination, have west declination, and those to the left, east declination. The large black circles or dots indicate the capitals of the several states. The use of this chart, is quite simple. The declination for any place within its borders is either found by inspection or by simple interpolation between the two adjacent curves; the value found ‘is for 1900. For any other year (and fraction), a reduction for secular change between the epoch and given date must be applied. The annual change of the declination during the period 1895-1900, expressed in minutes of arc, is indicated in the chart ( + for increasing west or decreasing east declination and — for the reverse motion). The amount varies in time, but not sufficiently during a brief interval of years to cause any serious inaccuracy, and the values given on the chart can be used for a number of years to come for all practical purposes; its variation with geographical position must be estimated from the map. THE TRANSIT. The transit is the only instrument that should he used for measuring angles in any survey where great accuracy is desired. The advantages of a transit over a vernier compass are mainly due to the use of a telescope. By its use angles can be measured either vertically or horizontally, and, as the vernier is used throughout, extreme accuracy is secured. The illustration shows the interior construction of the sockets of a transit having two verniers to the limb, the manner in which it is detached from its spindle, and how it can be taken apart when desired. The limb b is attached to the main socket c. which is carefully fitted to the conical spindle h, and held in place by the spring catch s. The upper plate a, carrying the compass circle, standards, etc., is fastened to the flanges of the socket k , which is fitted to the upper conical surface of the main socket c. The weight of all the parts is sup- ported on the small bearings of the end of the socket, as shown, so as to make as little friction as possible where such parts are being turned as a whole. A small conical center, in which a strong screw is inserted from below, is brought down firmly on the upper end of the main socket c, thus holding the two plates of the instrument securely together, and. at the same time, allow- ing them to move freely around each other. The steel center pin on which the needle rests is held by the small disk fastened to the upper plate by two small screws above the conical center. The clamp to limb d /, with clamp screw, is attached to the main socket. The instrument is leveled by means of the leveling screws l and placed exactly over a point by means of the shifting center. The plummet is attached to the loop p. The verniers on a transit differ from those on a compass in detail only. 90 80 1 70 ° ADJUSTING TUN TRANSIT. 41 The principle is the same. The transit vernier is so divided that 30 spaces on it equal in length 29 on the limb of the instrument. The method of reading it is practically the same as reading a compass vernier, except that of the transit the vernier is made with all of the 30 divisions on one side of the zero mark. Each division of the vernier is therefore or, in other words, 1 minute shorter than the half-degree graduations on the limb. In the figure the reading is 20° 10'. If the zero on the vernier should be beyond 20i° on the limb of the transit, and the line marked 10 should coincide with a line on the limb, the reading would be 20° 40'. In case the 12th line from zero should coincide with a line on the limb, the read- ing would be 20° 42', etc. In some transits, the graduated limb has two sets of concentric gradua- tions, the zero in both being the same, and, while the outside set is marked from 0° each way to 90°, and thence to 0° on the opposite side of the circle, the other set is marked from 0° to 360° to the right, as a clock face. The inside set has the N, S, E, and W points marked, the 0° of the inside set being taken as north. The interior of the telescope is fitted up with a diaphragm or cross- wire ring to which cross-wires are attached. These cross-wires are either of latinum or are strands of spider web. For inside work, platinum should e used, as spider web is translucent and cannot readily be seen. They are set at right angles to each other and are so arranged that one can be adjusted so as to be vertical and the other horizontal. This diaphragm is suspended in the telescope by four capstan-headed screws, and can be moved in either direction by working the screws with an ordinary adjusting pin. The transit should not be subjected to sudden changes in temperature that may break the cross-hairs. In case of a break, remove the cross-hair diaphragm and replace the broken wire. The intersection of the wires forms a very minute point, which, when they are adjusted, determines the optical axis of the telescope, and enables the'surveyor to fix it upon an object with the greatest precision. The imaginarv line passing through the optical axis of the telescope is termed the line of collimation, and the operation of bringing the intersection of the wires into the optical axis is called the adjustment of the line of collimation. All screws and movable parts should be covered, so as to keep out acid water or dust. If this is not done, the mine work will soon use up a transit. The vertical circle on the transit may be a full circle or a segment. The former is to be preferred, as it is always ready without intermediate clamp screws. If the dip of a sight is to be taken, the tape must be held at the transit head, and stretched in the line of sight. If the pitch of the ground is to be taken, the point of foresight must be at the same height as the axis of the transit, and the sight will then be parallel to the surface. The angle of dip is read “ plus” or “minus,” as it is above or below the horizontal plane. If we have the dip of a sight, and the distance between the transit head and the point of sight, we can get the vertical and horizontal components of that distance from the table of sines and cosines. ADJUSTMENTS OF THE TRANSIT. The use of a transit tends to disarrange some of its parts, which detracts from the accuracy of its work, but in no way injures the instrument itself. Correcting this disarrangement of parts is called adjusting the transit. First Adjustment.— To make the level tubes parallel to the vernier plate. Plant the feet of the tripod firmly in the ground. Turn the instrument until one of the levels is parallel to a pair of opposite leveling screws; the other level will be parallel to the other pair. Bring the bubble in each tube to the middle with the pair of leveling screws to which the tube is parallel. Next turn the vernier plate half way around; that is, revolve it through an angle of 180°. If the bubbles have remained in the middle of the tubes, the levels are in proper adjustment. If they have not remained so, but have 42 SURVEYING. tAwarrl pither end bring them half way back to the middle of the tfibes bv means of the capstan-headed screws attached to the tubes, and the tu + t? hflpt hv the leveling screws. Again turn the vernier plate through 180° and if the bubbles do not remain at the middle of the tubes, the correction. Sometimes the adjustment is made by one trial, but usually it is necessary to repeat the operation. Each level must be adjusted SeP SeMnd y Adjustment —To make the line of collimation perpendicular to the and carefully leveled, sight to a pin or *. about 400 ft. distant, ^nearly level G B- & 00 ' scope; that is, tarn it over on its axis until it points in the opposite direction, and set a point at about the same dis- tance, which will be at D. ^mestrallhtlinlwith A K It maybe necessary to repeat the operation t0 horizontal axis of the telescope parallel to the sSf S.-';Fs sas .W”lSsx plamn turn over the telescope, and turn the plate around suffi Sfvtoto take an approximately accurate sight upon the r»m' n t ^4 Then clamp the instrument and again take an exact Sght to 'the po?nt I P Next depress the telescope, and set another P fha PTonud which will come at G. The distance is l is dcmbfe the S e rror of adjustment. Correct the error by raising O? lowering one end of the telescope axis by means of a small '5A -d have [hfstakes driven down until l the . rod jading ^ the^ame on both stakes. gives equal rod readings on both s takes. THE CHAIN OR STEEL TAPE AND PINS. The chain, which is gene^l^50 or 10^ft. lon|, should temah^oOhneel^ CHAIN AND PINS. 43 provided. These handles should be attached to short links at each end, and the combined length of each-of these short links and one handle should be exactly 1 ft. The handles should be attached to the short link in such a manner that the chain may be slightly lengthened or shortened by screwing up a nut at the handle. It should be divided every 10 ft. with a brass tag, on which either the number of points represents the number of tens from the front end, or the number of tens may be designated by figures stamped on the tags. When a chain is purchased, one that has been warranted as *' Correct, U. S. Standard,” should be selected, and, before using it, it should be stretched on a level surface, care being taken that it is straight, and no kinks in it, and the extremities marked by some permanent mark. These marks can be used in the future to test the chain. It should be tested frequently, and the length kept to the standard as marked when it was new. In chaining, the chainmen should always remember the axiom that a straight line is the shortest distance between two points. Ordinarily, the chain should be held horizontally, and if either end is held above the ground, a plumb-bob and line should be used to mark the end of the chain on the ground. If used on a regular incline, the chain may be stretched along the incline, and, by having the amount of declination, the horizontal and vertical distances may either be calculated or found in the Traverse Table. For accuracy, steel tapes are now almost exclusively used by the leading mining engineers, on account of their greater accuracy as compared with Ch The steel tape is simply a ribbon of steel, on which are marked, by etching, or other means, the different graduations, which may be down to inches or tenths of a foot, or may be only every foot. It is wound on a reel, and may be any desired length up to 500 ft. . . , _ A well-made tape should not vary ft. in 100 ft., at any given standard of temperature. The steel of the tape should not be too high in carbon, or it will be brittle and liable to snap on a short bend, nor should it be of too soft steel, or it will stretch when strongly pulled. . , Careful gunsmiths can make and repair steel tapes with a high degree of accuracy and fully as reasonably as the instrument makers. For outside work tapes 1,000 ft. long have been made, but 500 ft. will be found as long as can well be used in a mine, owing to the lack of long sights, and to the increased weight of so long a tape. The average length is 300 ft. The 300 ft. are divided into 10-ft., 5-ft., 2-ft., or 1-ft. lengths, as desired, and the tenths and hundredths of a foot are read by means of a pocket tape or measuring pin Sometimes there is an extra division before the zero mark, which is divided into feet and the first foot into tenths. With such a tape, a distance can be accurately measured to tenths, or even quite approximately to hundredths of a foot. ...... .... , The ends are fitted with eyes on swivel-joints, to prevent straining by twisting. Handles of various forms have been devised to enable the tape to be stretched, or to clamp a broken end. Some parties use ordinary springs to prevent overstraining, and, in certain cases, spring scales are used, and the same degree of tension can be readily produced, and, m this way, the exact amount of sag can be calculated for any length, and the necessary correction made. To keep a mark on the tape for frequent reference, si clip (made by bending sharply on itself a piece of steel £ in. X 3 in.) is slipped upon the tape, where it will remain unless subjected to considerable force. Reels for winding the tape are made of iron of wood, and vary greatly in size and shape. „ ,, „ , When distances do not come at even feet, the fractional part of the foot should always be noted in tenths. Thus, 53 ft. and 6 in. should always be noted as 53.5 ft. . , _ , , , , Pins —pins should be from 15 to 18 m. long, made of tempered-steel wire, and should be'pointed at one end, and turned with a ring for a handle. When using a 50-ft. chain, a set of pins should consist of eleven, one of which should be distinguished bv some peculiar mark. This should be the last pm stuck by the front chainman. When all eleven pins have been stuck, the front chainman calls “Out!” and the back chainman comes forward and delivers him the ten pins that he has picked up, and he notes the “out.” When giving the distance to the transitman, he counts his “outs,” each of which consists of 500 ft., and adds to their sum the number of fifties as denoted by the pins in his possession, and the odd number of feet and fractional parts of a foot from the last pin to the front end of the chain. 44 SURVEYING. The accuracy and value of a survey depend as much on the careful work of the chainmen as on anything else, and no one should be allowed to either drag or read the chain that is not intelligent enough to appreciate the importance of extreme accuracy. , , . Pins are generally used in outside work, where they can be easily stuck into the ground, readily seen, and avoided, and the chances of their being disturbed are slight. Inside work generally contains S9 many chances of error in their use that they are usually abandoned m favor of other methods. If the sight be longer than the length of the tape, it is usua* to drive a tack in a sill or a collar at a point intermediate between the stations, and take a measurement to the tack from each station, with the dip 01 the sights; or a tripod is set up in the line of sight, and the horizontal distance is m easured from each station to the string oi the plumb-bob under the trinod The first method is the more accurate. Plumb-Bob.— The plumb-bob takes the place of the transit rod m under- ground work, as the stations are usually in the roof, and strings are hung from them to furnish foresights and backsights. Plumb-bobs vary m weight and shape. At various times and in various countries where mine surveys have been made, the idea ot sighting at a flame has been considered, and, from rough methods of setting a lamp on the floor on foresight and backsight, there have arisen various forms of plummet lamps. The idea is to continue the practice of sighting to a flame, but to make that flame exactly under the station, and to avoid the difficulty in sighting to the string of the plummet The idea is good, but there has never been, devised a plummet lamp that would be as free from error under all circumstances as the old-fashioned, plummet, so that the majority of the best engineers have gone back to the plummet. The best plummet is the one that combines the least surface with the greatest weight, and the ordinary shapes used for outside work are the best for inside also. In a “ windy ” place, a hole can be dug m the ballast of the track and the “ bob ” let into this shelter where it will be unaffected bv the air. The cord is best illuminated by placing a white paper or card- board behind it and holding the lamp in front and to one side. Kie string shows as a dark line against a white ground, and there is less difficulty m finding it than when the light is placed exactly behind it, and in this way a careless man cannot burn the string by poking the flame against it. The white background will also illuminate the cross-hairs of the transit. The backsight “ bob ” can be made of lead, as there are no “ centers to be set by this man A number of varieties have been made for the foresight, to aid him in “ center setting ” ; but all get out of order easily. A quick man will do as good work with the old-style bob, and have none of the accidents common to the others. In general, it may be said that the instruments used for outside work will be sufficient for mine work also. The clinometer, or slope level, is a valuable instrument for side-note work; but it is not accurate enough for a survey, and its place is taken by the vertical- circle on the transit. There are two styles of clinometer, with a bubble and with a pendulum. The latter is the old-fashioned and more accurate German “Gradbogen” that is found on some old corps. The bubble variety is much more easily rendered worthless by the breaking of the bubble tube and in general is not so accurate as the other style, which consists of a semicircular protractor cut out of thin brass and furnished with - books i at each end, that it can be hung on a stretched string so that the string v ill pass through the 0° and 180° points. The dip is read by a pendulum swung from the center of the circle. If made sufficiently large it will readily read to Quarter degrees. By inclining the string parallel to the surface and taiSngflieclinometer, the. dip will be obtained. A pocket instrument combining a compass and clinometer can be obtained from any dealer in surveying instruments. . FIELD NOTES FOR AN OUTSIDE COMPASS SURVEY. Call place of beginning Station 1. . Stations. Bearings. Distances . 1_2 N 35° E 270.0 At 1 + 37 ft. crossed small stream 3 ft. wide. At 1 + 116 ft. = first side of road. At 1 + 131 ft. = second side of road. , ^ . At 1 I 137 ft. = blazed and painted pine tree, 3 ft. left, marked for a “go by.” TRANSIT S UR VE YING. 45 Station 2 is a stake at foot of white-oak tree, sides for corner. 2-3 N 83i° E blazed and painted on four 129.0 Station 3 is a stake-and-stones corner. 3- 4 S 57° E 222.0 3 + 64 ft. = center of small stream 2 ft. wide. 3 + 196 ft. = white oak “ go by,” 2 ft. right. Station 4 = cut stone corner. 4- 5 S 34i° W 355.0 4 _ j- 174 ft. = ledge of sandstone 10 ft. thick, dipping 27° south. 5- 1 N56i°W 323.0 5 + 274 ft. = ledge of sandstone 10 ft. thick, dipping 25° south (evidently continuation of same ledge as at 4 + 174). Station 1 = place of beginning. TRANSIT SURVEYING. To Read an Angle.— The angle read may be included or deflected. If we set up at 0 with backsight at B and foresight at C, we shall find that there are two angles made by the line C O with the line BOA, namely the included angle B 0 C, and the deflected angle CO A. To Read the Included Angle.— Set the zeros of vernier and graduated limb together accurately, and clamp the plates. Turn the telescope on the backsight, with the level bubble down, and, when set, fasten lower clamp so as to fix both clamped plates to the tripod head. Loosen the upper clamp and turn the telescope to C and set accurately. The vernier will read, for example, ‘‘45° left angle.” To Read the Deflected Angle.— Arrange verniers as above, and be sure and turn the telescope over on its axis till the bubble tube is up, and then take the backsight and fix lower clamp. Turn the telescope back (this is called “ plunging” the telescope) and sight to foresight and fix as before. The vernier will read a ‘‘right angle of 135°.” The sum of included and deflected angles must always be 180°. Note.— In making a survey by included angles, we must add or subtract 180° at each reading to have the vernier and compass agree; by deflected angles, they will agree without the above addition or subtraction, and the latter method is generally used. TO MAKE A SURVEY WITH A TRANSIT. By Individual Angles.— Set vernier at zero of limb, plunge telescope, and, when set on backsight, loosen needle and read bearing of the line from back- sight to set-up. Plunge telescope back and set on foresight and read both needle and vernier. The difference in needle readings should agree with the vernier reading within 15', as local attraction will affect the needle equally on both sights. , , , . Note.— Any mass of iron or steel that may and will be moved during the readings of the needle, will affect the same and destroy the value of the needle as a check. The tape and other iron materials should not be moved during the taking of angles. By Continuous Vernier.— Set vernier at zero, unclamp compass needle, and, when stationary, turn the north point of compass limb so as to coincide with the north point of the needle. Fix lower clamp, plunge telescope, and take backsight by loosening upper clamp. The vernier and needle should agree in giving the magnetic bearing of the line from backsight to set-up. Record this in note book; plunge telescope, and take foresight. Needle and vernier should agree as before. After making record, set up over foresight and take sight to station just left with telescope plunged, having first seen that the vernier reads exactly as it did on the last foresight, as a slip in carrying the transit from one station to another, which is not detected at the time, can never be checked afterwards when the final work is found to be in error. The foresight is taken as before. On every sight the needle and vernier should agree if there is no local attraction of the needle. If we can see all the corners of a field that is to be surveyed from a central point, we can make the survey by setting up at that point, and, with one 46 TR ANSI T SURVEYING. porner as a backsight, take all the other corners as foresights with but one set-up and by measuring from this point to all of the corners; or we can set up’ at any corner and run a line of survey around the field. This latter method is called meandering. Both methods will give the same result when plotted- but the former is much quicker, as the boundaries of a tract are freemen tlv overgrown with bushes that must be cleared to allow a sight, 3 a SLtaapSnt can frequently be found that will allow a free sight to all the corners, and the distance can be measured by tape, or stadia. As the central point is nearer the corners than they are to one another it follows that a shorter distance must be chained or cut in the case of a central set-up. ^^Outsid^'sm'veys^ be made for many purposes It matters not what the purpose is, the work should be fully and accurately done, and the map should contain everything that will throw light upon the subject. If the outside work is to be connected with inside surveys, there are a number of points to be observed, and they will be given under the head of underground W °Meridians or Base Lines.— The surveys must be based on some meridian;, and started ’from some fixed point. There are four kinds of meridians, o bl First™ t line already on the ground, as one of the sides of the tract is taken as a base. The subsequent work is ends of thl& line and all angles measured are taken as deviations from it. Second.— A stone post is sunk in the ground, or, better, a u iron J® PJjJ into rock “in place that is, not loose rock, even if a large bolder— at such a distance from the works as to be beyond the influence of moving ^.machinery and a line of sight is taken to some permanent natural object, as far distant as can be clearly seen under adverse circumstances, as cloudy or dark weather. This line of sight is the base line, and the plug is the origin. N 9 measurements of distance are needed. If no natural objects exist, a station is se ^.^P a a distance so as to be as permanent as possible, and angles are turned from this to other points, so as to check any movement m it. Generally there are „ number of tall chimneys, church spires, etc. to be found. While this is preamble to the first, it Jives no method of check in underground work, an Tiy/-The magnetic meridian is taken as the base line. The transit is setup over a plug, as just noted, and the subsequent work is as described unde? running continuous vernier. As the needle is subject to constant Nation this%ase line will afford a check underground only for a short time after the meridian is established, and all subsequent work can be checked only by applying the difference between the variation at the time nf P^blishment and at the time of making the survey If the time of establishing the survey should be lost, the base line would become no better tha 2WA -The trae a me?idian is taken as a base. The true north and south bnp ruav be 'determined by observing the North Star, Polaris, or by observing Ihe sun y The N™Star loes not lie exactly at the North Pole, but revolves it in a small circle. There are two times m a day when it is exactly our ^transffe "do ^o^hlvetheS JmduatS hmte S? « e d St s a tar in crosses the meridian. . . The true meridian will give us an invariable base line At any date after the establishment of the same, we can check the work above or below ground by applying the variation of the needle. To Find the True North by an Observation of the North Star, Polaris, at Elongation.-This star has a motion around a small circle, the azimuth angle of winch from the north is known for different latitudes. The star may be readily found by following the line of the so-called pointers in the Big Bear, or Dipper. The time of the greatest eastern or western elongation is found from a table. Some 10 minutes before this time the transit is carefully set up and leveled over a peg. The cross-wires are made to bisect the star: they are jpo laris \ \ \ \ l I 1 1 I 1 l \ 1 \ ! \l \l V Observer THE SO LAX ATTACHMENT. 47 illuminated by a light held under the reflector fastened on the object end of the telescope. The star is followed with the cross-wires until its motion toward the point of its greatest elongation ceases. The telescope is lowered vertically, care being taken, of course, not to move it horizontally, and a peg is set up on the line, say 300 ft. or 400 ft. distant. The next morn- ing the correction is made for the star’s azimuth. These corrections are different for different latitudes and different years. They are to be found in the nautical almanac. , ... . , , , The method “by equal shadows” may be used with considerable accu- racv if we take a sufficiently long staff, or can obtain the shadows of a tall spire on a level surface. A vertical staff casts equal shadpws at the same time before and after noon. If we drive a stake at any time before noon, in the extremity of the shadow cast by such a staff, and measure its distance from the staff, we have one leg of an angle. After noon we wait till the shadow becomes exactly as long as the distance measured, and drive a stake at the extremity of the shadow. A line bisecting the angle made by lines drawn from these two stakes to the staff will be in the meridian. Establishing a Meridian Line With the Solar Attachment— The angle from the equator to the horizon of a place is its latitude; consequently, from the zenith to the pole is the colatitude , or 90 o _ latitude. The angular dis- tance from the equator to the sun is the decimation; consequently, from the sun to the pole is the polar dis- tance. The angular distance from the horizon to the sun is the sun’s . , , altitude; consequently, the zenith distance is the angular distance between the sun and the zenith. . „ . A . , , Adjustments of Burt’s Solar Attachment.— After the instrument has been carefully leveled, the zero of the vernier of the solar is placed opposite the zero of the arc. The horizontal plates of the instrument are clamped, and the sun’s image brought between the horizontal lines of either silver plate bv any manipulation of the instrument and attachment possible, keeping the plates horizontal and the zero of the vernier opposite the zero on the arc. When the image is accurately between the horizontal lines, the arc is revolved so that the image falls on the other plate; this must be done rapidly as the sun’s image moves. If it does not fall between the lines, half the error is corrected by the tangent screw of the solar and half by the tangent screw of the telescope. The operation is repeated until the sun s image falls between the lines of the second plate, after a revolution of the arc it having been made to fall between the lines of the first, as described. Near noon is a good time to make this adjustment, as the sun’s apparent motion is not so rapid. The zero of the vernier is now brought opposite to the zero of the arc by loosening the screws that fasten the vernier, and sliding it as may be necessary. It is often difficult to make the zeros come exactly opposite each other, as the vernier plate is apt to move slightly when the screws are tightened again. The second adjustment is to make the tons of the rectangular blocks of the solar attachment level, when the telescone is level and the arc of the solar is set at zero. Level the transit carefully as before described, set the solar at zero and plac^ the level, furnished with the solar, across the tops of the blocks. If the bubble comes to the center of the tube, no correction is needed; if it does not, correct the error bv turning the screws under the hour circle, care being taken m this as in ali other movements of these adjusting screws, to leave them tight after the correction. Revolve 180° and correct again if necessary. Placing the blocks 90° horizontally from their first position, go through the same operation as described until in all positions the bubble remains centered. To Use the Solar.— Before this instrument can be used at any given place, it is necessary to set off upon its arcs both the declination of the sun, as affected by its refraction for the given day and hour, and the latitude of the place where the observation is made. 48 TRANSIT S UR VE Y1NG. The declination of the sun as given in the ephemeris of the nautical almanac from year to year, is calculated for apparent noon at Greenwich, England. To determine it for any other hour at a place in the United States, reference must be had. not only to the difference of time arising from the difference of longitude, hut also to the change of declination during that time. The longitude of the place, and therefore its difference m time, if not given directly in the tables of the almanac, can be ascertained very nearly by reference to that of other places given which are situated on, or very nearly on, the same meridian. It is the practice of survevors in states east of the Mississippi to allow a difference of 6 hours for the difference in longitude, calling the declination given in the almanac for 12 M. that of 6 a.m. at the place of observation. Beyond the meridian of Santa Fe, the allowance would be about 7 hours; and in California. Oregon, and Washington, about 8 hours. Having thus the difference of time, we verv readily obtain the declination for a certain hour in the morning, which would be earlier or later as the longitude was greater or less, and the same as that of apparent noon at Greenwich on the given day. Thus, suppose the observation made at a place 5 hours later than Greenwich, then the declination given in the almanac for the given day at noon, affected by the refraction, would be the declination at the place of observation for 7 a.m. This give us the starting point. To obtain the declination for the other hours of the day, take from the almanac the declination for apparent noon of the given day, and, as the declination is increasing or decreasing, add to, or subtract from, the decli- nation of the first hour the difference of one hour as given in the ephemeris, that will give, when affected by the refraction, the declination of the succeeding hour. Proceed in like manner to make a table of the declinations for every hour of the day. To Find the True North With the Burt Solar.— Find from an ephemeris or nautical almanac the sun declination for noon of the day of observation at Greenwich. Find the declination for the hour of observation at the place of observation bv first figuringwhat time it is at the place of observation when it is noon at Greenwich. If the place of observation is west of Green- wich it will be earlier there; if east, later, and in either case the difference will be one hour for everv 15° of longitude. If the place is west, subtract the hour just found as described from the hour of the observation, and multiply the hourly difference, also taken from the ephemeris, by the remainder. If the declination is increasing from the equator either north or south, add this product to it; if decreasing, subtract it. A table of refractions is given in the ephemeris for the different latitudes and the different hours of the dav. This refraction is to be added if the declination is north, and subtracted if the declination is south. Having thus ascertained the declina- tion, lay it off on the declination arc. Set the colatitude of the place off on the vertical arc after having leveled the instrument carefully with clamped horizontal plates at zero. Alwavs in solar observations it is well to level by means of the upper telescope bubble. Now, revolve the horizontal plates still clamped and also the declination arc. around its polar axis until the sun’s image is exactlv between the horizontal lines of the silver plates. When the sun’s image is between these lines, the object end of the telescope will be pointing north. , _ To Take the Latitude With Burt’s Solar.— A few minutes before apparent noon clamp the plates at zero, level the instrument carefully, and set the zero of the vernier opposite the zero of the vertical arc. Lay off the declina- tion, corrected for noon at the place of observation and for refraction, on the declination arc, and set the time mark on the declination arc opposite XII on the hour dial. Bring the sun’s image between the horizontal lines of the silver plate bv moving the plates horizontally and the telescope vertically, clamp both plates and telescope and follow with the tangent movements the rising sun. Be careful to stop when the sun ceases to mount. For a moment before apparent noon there is no perceptible motion of the image. The reading on the vertical arc is the colatitude of the place. The colatitude should never be taken this way for direct-sight calcula- tions for while it satisfies the automatic solution of the true north, it may not be accurate, and the latitude needed for direct-sight calculation should be true to within a minute. With the Burt solar there is at times what is called a false image to guard against, an image that comes between the lines of the silver plates when the object end of the telescope is not pointing TRANSIT S UR VE YINQ. 49 north If the time be observed on the hour dial, or the magnetic north be noticed, no error need ever occur on this score, for with the false image the time will be out considerably and also the magnetic variation. General Remarks.— With the base line located and the survey made, we see, by coming back to the point from which we started or “ closing” the work, whether it be correct in distance or angle. If it be in error, see if the error can be located (as will be shown under plotting), and if it can be tound, run those parts over again; if not, repeat the whole survey. Shoving the work, as it is called, or “doctoring” it so that it will close, is the poorest practice that an engineer can engage in, as all subsequent work that depends on a doctored survey must be doctored to tit the faulty work — even it it be right in itself. Every engineer should be able to swear— not that he “ thinks the survey is accurate,” but “that he knows it to be so,” if he should be called as a witness in court. One of the causes of inaccuracy is haste. To make a complete map, the engineer should first make a survey around the tract to be worked, locating all the prominent physical features and improvements. If he can do so, he should make a topographical map of the tract at once; but, if time is limited, by running the vertical as well as the horizontal angle, he can carry the tidal elevation or the elevation above some assumed datum, to every station, and murk it on the map at that point. Then as he makes subsequent surveys, he can gradually get data enough to make a fairly complete topographical map in course of time. Every ledge of rock in place should be located, and the amount and direction of its dip, as well as the character of the rock, should be marked neatly on the map. The streams of water on the tract should be regarded as of primary impor- tance, and should be located with exactness. With a true meridian base line we can connect maps made at different places with little trouble. This is especially useful with adjoining mines connected at but one point. Having made the survey and come home, we must examine all the apparatus and see if the instruments are out of adjust- ment, as such a fact will prevent our bothering over work that will not close It will assure us, also, that we can start out at a moment’s notice with no thought of the adjustment of our tools. A famous wit said that the proper time to strop a razor was just after you had used it, as you then knew how much it needed it. The same will apply to surveying instruments and tools— especially for underground work. Here the lamp smoke, powder gases, mine dust, paint smears, acid water from “droppers,” and the other abominations incident to underground surveying, especially in a coal mine, will so cover the tools that they would be useless if left uncleaned half a dozqn times. As soon as the corps comes back from the mine, and before the clothes are changed, the tape must be stretched, tested, wiped, and oiled. It can be inspected to see if marks are too much worn, or it stands in need of mending, the marking pot is cleared of “muck,” and fresh white paint is mixed, if the corps is going out in 24 hours; the plummets will have their strings overhauled and freed from knots; hatchets will be sharpened, and axes ground, pouches overhauled, and a supply of tacks or “spads” taken. Then the transitman changes his clothes and sets up the transit, wipes it with a cloth wet with alcohol, so as to remove dirt, oil, and paint. If water has gotten between the graduated limb and compass box, the verniers must be uncovered and the whole wiped dry. If the sulphureted hydrogen from the powder smoke has tarnished the silver surfaces of any of the graduated circles, it must be removed with whiting. Alcohol should be always used instead of water, as it will quickly evaporate and leave the parts dry. The telescope glasses are then wiped with soft chamois leather, and the instru- ment is tested for want of adjustment before putting it away in its box. When going to and from work, the transit should not be carried on the transit head, or the spindle will become sprung. Nor should it be carried with the arm crooked under the telescope, as the weight comes on the axis, and that soon gets sprung so that all the adjusting in the world will not make it work right. When carried in the hand, it should be reversed and the hand slipped under the compass plate and brought over so as to clamp both plates. In this way there will be no strain on any part. In case of a “fall” in the mine, remember that the transit is the baby to be protected, and stand a few bumps to save a strained or broken instrument, that will end the work for some time. ‘ Plotting.— A “plot” is not only a piece of ground with bodies of water, roads, vegetation, etc. upon it, but refers also to the map of the same drawn to a given scale, and showing all of the above natural features. Plotting is 50 TRANSIT S UR VE YING . the making of such a map from notes of a survey, and may or may not require the permanent placing of the stations on the map, by which the survey is made. In- underground work, the exact location and the retention of those stations is a matter of the first importance, and is secondary only to the exact ploUing of the side notes. The scale of the plot is generally as large as will show the points of interest m the Pennsylvania, the maps for coal mines must be drawn to a scale of 100 ft. to an inch There are two methods of plotting: by protractor, and by coordinates. When the scale is sufficiently large, it is a matter of little choice which method is used, if the work be carefully done with exact instruments, but with small scales-100 . ft. or above, to the inch— we should use the method bv coordinates. With the latter scale, the prick of a pm on the paper will^ represent a foot square, or a circle slightly larger than a foot m diameter. If the next station is to be located from the pin prick of the first, and that is exactly located, we may not hit the exact cenr-CT 9*^^ small indentation. In fact, the chances are greatly against our doing so, and the location of the second station will probably be in error. If we have a bad habit of placing the protractor or the straightedge against one side of the pin pricks, or pencil marks, when the scale is large we be introducing a “ personal error, as it is called; and the sum of all the errors made at each of 100 stations will bring our final point very much _out of the way. On this account, and from the fact that no protractor that is movable can be used without the chances of shppmg while the angle is read or marked, has led all careful engineers to abandon its use m favor of the method by coordinates. When the scale is from 1 to 2o ft. to an inch the errors are small enough to make little chances of variation in a cl ?s e often or twelve stations; when the survey is of short sights from a mam line to points where no further work is to be done, the protractor will afford a quick me Th°ere°i a ?han?'e of error in both methods that must he noted here, where the survey is not completed at one time. If the map be made m a day or two, and will never be extended by subsequent work, there will be no chance of error from a change in the paper on which it is made, due to moisture or dryness; but if the map be made on a series of very damp days, or a series of very dry ones, a change in the weather to the other extreme will swell or shrink the map. The general tendency in a large mine map that is frequently used, and is rolled and unrolled every day for ^ sg years, is to stretching, so that there will be a variation of from l to 5 ft m 1,000. If we extend a recent survey on such a map, we are plotting it to a different scale to that assumed by the map under , ^wri noted. The paper on which the map is to be drawn should be tacked down to the table or board, and should be covered with squares each exactly 10 in. square. The sides of these squares should be the meridians, or north or south lines, and the tops and bottoms should run due east and west. Mark the first station on the paper, set your parallel ruler or T square on the meridian nearest it and with the protractor produce the course to the next station. Measure the distance with a scale, and proceed in this manner to plot all the courses using each time the meridian nearest the station the course is taken from. After all the stations have been plotted, fill in the side notes, marking the map with great care and neatness. Always use the horizontal distances. All surveys should be traversed, and all plotting should be eithei checked bv the traversing, or the principal stations should be plotted by use of the traverse. For a large mine map that will be in use many years, muslin- backed egg-shell paper must be used. It comes in a long roll, and any reasonable length, and a width up to 6 ft. can be obtained. To Calculate the Vertical Distances.— When making the survey, read the vertical angles to all stations. If the angle is one of depression, note it vuth a minus sign (— ) preceding it. If it is an angle of elevation, precede it with a plus sign ( + ). These will show whether the vertical distance is to be added to, or subtracted from, the height of the preceding station. Having the horizontal distance and the vertical angle: Distance X tangent of vertical angle = vertical distance. Having the pitch distance and vertical angle: Distance X sine of vertical angle = vertical distance. To Calculate the Horizontal Distance, or Latitude.— Pitch distance X cosine of vertical angle = horizontal distance. . r Vertical height, or departure h- tang.of vertical angle = horizontal distance. TRANSIT S UR VE YINQ. 51 Tv Calculate the Pitch Distance.— Horizontal distance — cosine of bearing, or multiplied by secant of bearing = pitch distance. Vertical distance -i- sine of vertical angle, or multiplied by cosecant of bearing = pitch distance. To Calculate the Vertical Angle.— The horizontal distance -- the pitch distance = cosine of vertical angle. Vertical distance -5- pitch distance = sine of vertical angle. Vertical distance -4- horizontal distance = tangent of vertical angle. Note.— W henever sines, cosines, tangents, etc. are here named, they mean the natural sines, etc. of the angle. . Plotting by Coordinates.— In describing the establishment of a meridian and a fixed point, we made the latter a stone post, or iron plug sunk in. solid rock. This point is called the origin of coordinates. We have the principal meridian passing through this point in an exact north and south direction, and a secondary meridian or base line passing through this point at right angles to the first, or in an exact east and west line. Any point we may select on the map will be a certain distance north or south, and east or west of the origin. The lines drawn from this point at right angles to the two base lines just given are called the coordinates of that jpoint, and we can plot the point when they are given. For example, the coordinates of Station 24 are North 845.67, and East 890.12. We measure 890.12 ft. east of the origin on the secondary meridian and, from this point, measure 345:67 ft. north to the point desired; or we can measure first on the primary meridian to the north and then turn off a right angle to the east and reach the same point. In any event we plot the position ol' each station independently of all the others, and any error in locating one is not carried to the next. When two stations are plotted, the distance between them on the map should be exactly what we found for their horizontal distance on the ground. This check shows whether our plotting is correct. This is also called traversing a survey if the meridian be north and south, and in books on surveying there are printed traverse tables , which are accurate within certain limits, but not so accurate as the tables of coordinates published separately, as the latter are carried to a greater number of decimals. Gordon’s Traverse Tables will enable you to find, without calculation, the coordinates for a distance of 12 miles with a chance of error of only half an inch, which is much more accurate than the graduation of the instruments with which the work was done. With a north and south meridian, the point from which we begin to measure angles— the zero point— is the north point, and the angles are read for continuous vernier in the direction of the hands of a watch. The sines of angles are eastings and westings, and the cosines are northings and southings. To Traverse a Survey.— To traverse a survey, means to determine by calcu- lation how far north or south and east or west any station may be from another, the location of which is fixed. To do this, all distances must be either measured horizontally, or calculated to horizontal distances. The horizontal angles, or courses, must be either read as quadrant courses, or reduced from azimuth to quadrant courses. An azimuth course is one that is read on the transit which is graduated from 0° to 360°. A quadrant course is one read in the quadrant of the circle, as S 67° W, N 43° E, etc. Latitude means distance north or south, and is determined by the first initial of the recorded course. Thus, if a course is S 67° W, the latitude is south; if N 43° E, the latitude is north. Departure means distance east or west, and is determined by the last initial of the recorded course. Thus, if a course is S 67° W, the departure is west; if N 43° E, the departure is east. The latitude = distance X cosine of bearing. The departure = distance X sine of bearing. If the survey is a continuous one around a tract, and ending at the place of beginning, the sum of the northings should equal the sum of the southings, and the sum of the eastings should bqual the sum of the westings. Or, in other words, the sum of all the latitudes north, should equal the sum of all the latitudes south; and the sum of all the departures east, should equal the sum of all the departures west. It is evident that by coming back to the place of beginning the surveyor has traveled the same distance north as he has south, and the same distance east as he has west. The most accurate way to construct a map is to traverse the survey and place all stations on it by the traversed distances, or to at least put a number of the principal stations on the map by the traversed distances, and 52 transit sur veying. use the protractor to the survey is at the fixed f ^ of this point from the pencil sketch to find the a PPJP^i^ enera f trend of the property itself, boundaries of the property , ai t t f 1 ? e g or “|j„ upon the paper so that all of This will show us the place to 0 f d P about the same amount of the property can be placed on tne map, anu north and souih margin on all sides. It will also ^° h Ts^ settled mXthe origin by a needle line must take on the paper When this f tueQ^ mar s point, and lay the straightedge across it «) a quite hard pencil principal meridian and draw Then lav off on both sides of the origin brought to a very hue P 0 *™ • t h needle points. These must he so distances of 5 in., and mark the an err() P of one hundredth of an accurately located that there' ^^^dred At the point where we can get inch in them, or °ne ^ot m f angles to the principal meridian, lay the longest line on the paper at right Qf the meridian, and off points for a right angle ac £ ara y f the straightedge, a lme parallel draw through the three th^ accurately into 5" distances as to the secondary meridian an^ lines at right angles before. Through each ot the points thus manw , ,1 squares to the lines already drawn, until the paper ^ accurately ^ flvedlulldred th. 5 in. on a side, and n0 .n e o^hem extremities ofthe lines passing through Beginning with the origin mark the side 0 f the north and it zero. All distances to the east o P tQ that p ne; those to the left are south zero line are marked + P ii ne are marked + marked - . A1 distances above : the east anawes^ _ If the coordinates of with respect to that line, and a d t measur e the whole east Stations. , Quadrant Courses. 1 Distances. Latitudes. Departures. S E W 1-2 2-3 a-4 4-5 N35°E N 83° 30' E S 57° E S 34° 15' W 270 129 222 355 221 15 121 293 155 128 186 200 1 236 414 469 200 Totals. N S E W 221 155 236 283 115 469 178 269 for latitudes and ine iorcgumg is 2 21 ft north and 155 it. easx oi oiauuu a, by the rule given under tPe heacl tie diyideit int0 triangles and same number of stdes. If a^ nregi these area s will be the area of ‘ K wittfthe greatest ^arej owing 0 to^iaWUty to error through very slight mac- curacies of measurement. Tract.— If the seam lies flat, To Find the Contents of a Seam ofCoal Under* ^ c thickness of th e seam in multiply the area of the ^act “ square leer oy i seam in feet . if the slam is -- «nd Us area® by measuring the width of the tract on its line the hor This w: byft^hiAnessTvill give thb contente.^ . p feet x gp Gr- x 62 .5 feet. The product will ° e “f I 1 ' me^uring the width of the tract on seam is an inclined one, hnd ^its 1 area .by mea ^ of the seam by dividing its line of pitch and find the distance on tne p ^ the angle of inclination, the horizontal distance measured by e ^°sine the p i tc h distance by the strict Mid you h whl have the area’o? the seam. This multiplied icufii'u • 4-v» a nAtitonrs . ^ Tons of coal = 2,240 LEVELING. 63 LEVELING. Instruments.— But two instruments are used— the level and a leveling rod. The level consists of a telescope to which is fitted, on the under side, a long level tube. The telescope rests in a Y at each end of a revolving bar, which is attached to a tripod head very similar to that used tor a transit. The telescope is similar to the telescope of a transit. The leveling rod is merely a straight bar of wood, 6 ft. or more in length, divided into feet and tenths of a foot. A target divided into four equal parts by two lines, one parallel with the staff, and the other at right angles to it, and painted red and white, so as to make it prominent at a distance, slides on the rod and is provided with a clamp screw. The center of the target is cut out and a vernier, graduated decimally, is set in, which enables the rodman to read as close as of a foot. If a long rod is required, it is made of two sliding bars, which, when closed, are similar to a single rod, as described above. When used at points where it is necessary to shove the target to a greater height than 6 or 6£ ft., the target is clamped at the highest graduation on the front of the rod, and the rod is extended by pushing up the back part, which carries the target with it. The readings, in this case, are made either from the vernier on a graduated side, or a vernier on the back. The rodman must always hold his rod perfectly plumb or perpendicular. To Adjust the Level.— The proper care and adjustment of the level is of great importance. A very slight error in adjustment will completely destroy the utility of any work done. To Adjust the Line of Collimation. — Set the tripod firmly, remove the Y pins from the clips, so as to allow the telescope to turn freely, clamp the instru- ment to the tripod head, and, by the leveling and tangent screws, bring either of the wires upon a clearly marked edge of some object, distant from 100 ft. to 500 ft. Then with the hand, carefully turn the telescope half way around, so that the same wire is compared with the object assumed. . Should it be found above or below, bring it half way back by moving the capstan-headed screws at right angles to it, remembering always the invert- ing property of the eyepiece; now bring the wire again upon the object, and repeat the first pperation until it will reverse correctly. Proceed in the same manner with the other wire until the adjustment is completed. Should both wires be much out, it will be well to bring them nearly correct before either is entirely adjusted. To Adjust the Level Bubble.— Clamp the instrument over either pair of leveling screws, and bring the bubble into the center of the tube. Now turn the telescope in the wyes, so as to bring the level tube on either side of the center of the bar. Should the bubble run to the end, it would show that the vertical plane, passing through the center of the bubble, was not parallel to that drawn through the axis of the telescope rings. To rectify the error, bring it by estimation half way back, with the capstan- headed screws, which are set in either side of the level holder, placed usually at the object end of the tube. Again bring the level tube over the center of the bar, and adjust the bubble in the center, turn the level to either side, and, if necessary, repeat the correction until the bubble will keep its position, when the tube is turned half an inch or more to either side of the center of the bar. The necessity for this operation, arises from the fact that when the telescope is reversed, end for end, in the wyes in the other and principal adjustment of the bubble, we are not certain of placing the level tube in the same vertical plane, and, therefore, it would be almost impossible to effect the adjustment without a lateral correction. Having now, in a great measure, removed the preparatory difficulties, we proceed to make the level tube parallel with the bearings of the Y rings. To do this, bring the bubble into the center with the leveling screws, and then, without jarring the instrument, take the telescope out of the wyes and reverse it end for end. Should the bubble run to either end, lower that end, or, what is equivalent, raise the other by turning the small adjusting nuts, on one end of the level, until, by estimation, half the correction is made; again bring the bubble into the center and repeat the whole operation, until the reversion can be made without causing any change in the bubble. It would be well to test the lateral adjustment, and make such correction as may be necessary in that, before the horizontal adjustment is entirely completed. 54 transit s ur verm To Adjust the «... ,-Ha^ng - ef now to descnbe that of . t0 thevertical axis, so that the bubble level into a ^ entire revolution ’of the instrument, will remain m the ^"‘rt.iihe hrectly over the center of the bar, and clamp To do this, bring the level tube directly o v before over two of the leveling the telescope hrm t 1 >7? n eket leve?^ the fubbie, and turn the instrument halt screws, unclamp .the wcket level^ne dudd ' tbe ^ me position with respect way around, so that the ievei ba > the bubble run to either end, bring to the leveling beneath^ Should^the wome ^ bar; now move the ill^cop^vefthe^ther sit of level! ^^^-ews, bring t^hbteagin into If^crewf ’succes’Sv!?® until thl adjustment is very nearly perfected, when brought precisely to its i ormer atuat • made and the soc kets well completely adjusted, ! f the 11 ^men P P bubble wlll reverse over each fitted to each other and tne tnpou . . b unable to make it pair of screws m auy^m- f^ond the engmee c y t e S" “ Sm prob.il, b.' 1. Ur. imperfecttuu «, rh. interior spindle. __ tQ of the i eve l have been effected, and the bubble After the adjustments oi -tne socket, the engineer should remains in the center m an P n( j sighting upon the end of the carefully tmn the telescope he w> ^ Jong each side of the wye, level, which has the Q ^ r ri v z ®^ { ! 1 ^possible Whin this has been secured, make the tube as n^lye^c^asposb vertieal e(Jge of a building, he may observe, through the teiesc p , he should loosen two of and the adjustments of the level will be complete. ^otrnmpnt the legs must be set firmly To Use the Levf .-^en usmg the ms^ment, me ^gs^ ^ be into the ground, and neither r the > na ^ ^ brought over each pair of g££ sting the w d il“c^y to tJ*%& the object distinctly in view, SO that all errors of P a ^^. x t ?i ay 1 ^^fln^bserver is moved to either side of This error £*&**%* telescope in which the foci of the object and the center of 1£e <7^®°® Brlciselfupon the cross-wires and object; m such eyeglasses are not brought precisely up surface, and the observation a case the wires will appear to n » Te 5™ Les the wires and object should be will be liable to inaccuracy. spider lines will appear to be fastened brought toto view so i^rfe^y that the £ P to™ hoW ever the eye is moved to the surface, and will lernain m i n fi ly set in the tripod head as If the socket of the 11 s rument ■becomes so nrmij e shou f d place the to be difficult .of remove tor l the ^ binary way toe e „ aud a ^eS u"^ ^ to the blr, Scire also to hold his hands so as to grasp it the moment it is free. carefully made and vertical angles Field Work. If the survey has heen camuiiy ^ ^ where extreme taken at every sight, leveling will oe nece * In mos t cases of accuracy in regard to “eta^ng thickness of strata, practical work at ^ ide r p ad etc., the elevations calculated by the general rise or fall of j an made roa . , - Q ugh, but there are frequently use of the vertical angle will be close e g g ^ ccegs in certA in work. In instances when leveling ; must ^donet transit telescope is supplied ihs note book ruled, the levelman » ready to proceed with the work. FIELD WORK. 55 The rodman holds the rod on the starting point, the elevation of which is either known or assumed. The levelman sets up his instrument somewhere in the direction in which he is going, but not necessarily, or usually, in the precise line. He then sights to the rod and notes the reading as a backsight or +■ (plus) sight, entering it in the proper column of his note book, and adding it to the elevation of the starting point as the “ height of instrument.” The rodman then goes ahead about the same distance, sets his rod on some well defined and solid point, and the levelman sights again to the target, which the rodman moves up or down the rod till it is exactly bisected by the horizontal cross-hair in the telescope, as he did when giving the backsight. This reading is noted as a foresight or — (minus) sight. The foresight subtracted from the height of instrument gives the elevation of the second station. The rodman holds this latter point, and the levelman goes ahead any convenient distance, backsights to the rod, and proceeds as before. In this case we have assumed that levels are only being taken between regular stations or two extreme points. If a number of points in close proximity to each other are to be taken, the rodman, after giving the backsight, hoids his rod at each point desired. The readings of any number in convenient sighting distance are taken and recorded as foresights, and any descriptive notes are made in the column of remarks. These are each subtracted from the height of instrument, and the elevation found is noted in column headed elevation. After all the inter- mediate points are taken, the rodman goes ahead to some well-defined point, which is called a “turning point” (T. P.) in the notes. The elevation of this is found and recorded. The rodman remains at this point until the levelman goes ahead, sets up and takes a. backsight. This backsight reading, added to the elevation of the turning point, gives a new height of instrument from which to subtract new foresights, and thus obtain the elevation of the next set of points sighted to. When running levels over a long line, the levelman should set frequent “bench marks.” These are any permanent well-defined marks that can be readily found and identified at any future time. By leveling to them he has secured the elevation of points from which to start any subsequent levels that may be necessary. A good bench mark can always be made on the side or root of a large tree or stump by chopping it away so as to leave a wedge- shaped projection with the point up. Drive a nail in the highest point of this, to mark where the rod was held, and blaze the tree or stump above the bench mark. In this blaze, either cut or paint the number of the bench mark, which should, of course, correspond with the number in the note book. In the mines, prominent frogs or castings in the main roads, if permanent, make good bench marks. Level Notes. Station. B. S. i F. S. H. Inst. Elev. Remarks. 1 100. Assumed elevation of Station 1. 3.412 103.412 2 4.082 99.33 Station 2 of survev. See page Vol 6.791 96.621 Sight taken to ground at N. E. cor. John Smith’s house. 3 = T. P. 4.862 98.55 Station 3 of survey noted above. 11.698 110.248 4 9.817 100.431 Station 4 of survey noted above. B. M.l 6.311 103.937 B. M. 1 is on north side of large white oak. 5 6.427 103.821 Station 5 of survey noted above. In underground leveling, extreme care must be observed to record the algebraic signs of the readings, which show whether the level rod was held in its usual position, indicated by a + sign or the absence of any sign, or upside down, indicated by the — sign. Proof of Calculations.— The calculations are proven by adding together the backsights and also the foresights taken to turning points and last 56 UNDERGROUND SURVEYING. station. Their difference equals the difference of level between the starting point and last station. Thus: Foresights. Backsights. 4.862 3.412 61427 11-698 11.289 15.110 11.289 a 821 = 108.821 — 100.0 or 3.821. TRIGONOMETRIC LEVELING. for the leveling of mine slopes and pitching rooms where the Y level can- not be used with any advantage or accuracy. By reading the angles and by checking the measurements a very high degree of accuracy can be ob- tained in trigonometric leveling. Case 1. Assume the elevation of A to be 100 ft. A. T. With the transit set up over A and properly leveled, sight to a point C on a rod so that B C equals A D. Measure the vertical angle ■I AQ I Q Case 2. Assume the elevation of station A in the -roof of a mine to be 100 ft A. T. Then with the transit set up directly under A and properly leveled sight to a point C upon the plumb-line suspended from the station B, measure the vertical angle X, m- dined distance D C, and roof distance B C From this, the distance C F — n CY sin X. The elevation of B is then found as follows: The elevation of B = the elevation of A AJJ-t diagrams the most complex modifi- cations can be worked out. Trigonometric Level Notes. Station. Vertical 1 Angle. Inclined Distance. Vertical Distance. Height of Instrument. Roof Distance. Eleva- tion. A A- B B - C C -D D— E H — h 1 1 100 100 100 100 +8.72 +3.49 —5.23 -6.98 2' 3' 4' 2' 3' 2' 3' V +100 109.72 112/21 105.98 98.00 UNDERGROUND SURVEYING. been grouped together for convenience of reference. STATIONS. 57 The Establishment of Stations.— As this is the most important duty of an engineer in surface work, so it takes the first place in work underground, as the accuracy of the work depends on the location of the stations, while its rapidity depends on using the fewest number consistent with completeness. It also stands to reason that the fewer the numbe’r of stations, the fewer the chances of error. In underground work, stations should be located under the conditions of permanence, freedom from destroying agencies, and ease of access. Temporary stations for a single sight need not fill all these require- ments. We establish them generally in the roof of the mine— less frequently in the floor. In the former case we must establish a “ center” before each set-up of the transit, and thus underground differs from surface work. The first surveys were made with lamps set on the floor, sighted to, and then set over. Permanence was secured by driving iron nails or tacks in the sills of the track or sets of timber. As acid water soon destroyed these, they were followed by copper tacks or brads, and all were witnessed by notches cut on both sides of the sill, as in outside work, and by a vertical paint mark on the solid wall, with the number of the station. This method is faulty, as the tracks in crooked gangways are seldom placed where one can get the longest sight, and, as they are the traveling ways, the stations run the chance of being knocked out by passing men or mules, and the whole track, on a curved incline, is generally sprung by every loaded trip. As the sights must be as long as carefulness of work will allow, we put them generally in the roof, as that offers the greatest area for a choice, and is not under foot. Any settling of the roof so as to affect the accuracy of the station would be equally effect- ive in destroying the accuracy of a station in the floor. We therefore choose places that will be least affected by subsequent work, and put the stations in collars, lids or wedges of props, in the props themselves, when they have incline sufficient to allow the transit to be set under them, or in the roof itself. Wherever set, they should not project far from the surface, and thus be liable to be brushed away in a low gangway by cars with topping higher than usual, or knocked away by flying fragments from a shot, if near the working faces. Top stations have a mark about them to call attention to their location. It is generally a circle, unless there are other corps at work in the same mine that use the circle, and the stations of the two surveys would be confused if marked alike. In this case a corps selects some easily made figure, as a triangle, square, etc. If two surveys use the same station, the mark of the second survey is placed around that of the first, and the “ Remarks ” give “ Station No. 234 of L. & S. corps,” etc. Kinds of Stations. — The simplest top station is a shallow conical hole, made with the point of the foresight man’s hatchet, which is dug into the top rock and rotated, and is called by some a jigger station. Corps using these entirely have a jigger consisting of a steel-pointed extension rod, with an offset hold- ing a paint brush. The rod is long enough to allow the point to be driven into the roof at any height, and its rotation marks a circle with the brush, which is also used to mark the number beside it. Centers are set under such stations and sights are given by another tool— also called a jigger. This is an extension rod, beyond the upper end of which projects a piece of sheet iron shaped like an isosceles triangle, with the upper and smaller angle cut off so as to form an end one-quarter of an inch broad, and in this end is cut a U-shaped groove. The sights are given and the “ centers ” set by putting the plummet cord in this groove, and placing the end in the “jigger hole” in the roof. The cord must be more than twice the length of the section of the place, as it must be held in the hand, run over the jigger notch, and hang vertically to the plummet, which must come to the floor when the stations are set. The rod and cord are held in the left hand, and the right is free to steady the “bob,” give sight, or set the center. The advantage of this method lies in the quickness with which -the centers are set and the sights given, and the ease with which the highest stations are reached. The disadvantages are the impossibility of making the jigger hole perfectly conical, so that the jig- ger can be set in the same place on two successive sights, and the plummet cord will hang exactly in the same place. Second.— Common shingle nails are driven into collars, or cracks in the roof. The end of the plummet line is noosed and put over the head. This causes an eccentric hanging of the plummet that may cause an error in back- sight and foresight of the width of the nail head, which will be quite appreci- able in a short sight. To do away with this error, a variety of nails ( called spads , spuds , etc.) are made of iron or copper. Iron will not corrode in dry mines, 58 UNDERGRO UND S UR VE YING. k rrmoli cheaper The simplest is made by hammering out the head of a horsesSe or mule^shoe nail, punching a hole in the flattened head for insert- ing the cord and cutting off the point, so as to make the finished spad an inch Ion 0- This will bring, the head near the surface without having to drill toodeena hole and will make them unfit for lamp picks as they are very handv for such purposes, and thousands have been pulled out to this end. Anv blacksmith can furnish them for less than 1 cent each. They are driven broadside to the line of sight, or they will be liable to the same objec- tion as the shingle nail. To remove all chance of eccentricity, a form is made with a shoulder in which a hole is drilled parallel to the length of the nail The practice of using staples for stations is antiquated though gi\ en iii the last editions of soml modern textbooks-and should never be used wh ^, a d C ^In : SSta Of spads are driven into a crack of the roof; but such stations cannot be called permanent , as the same force that made the crack will tend to open it and let the nail drop. Even if this does not hap- pen we shall have the water in a wet mine coming in by these cracks, and rotting 6 the nails, or the rock at the sides of the crack, and m a month after tVip nlnoixiff of tli6 st&tion. it will b6 unfit for usg* . , Fourth -Into a hole drilled in the roof, a wooden plug is driven, and into thiswe drive the spad. The swelling wood clamps the same and prevents i ccnfong out as readily as it was put in. The plugs are made of well-dried and are carried bv the man that sets the stations. The first holes were made by a jumper, and the plugs were 2 in. square and 6 m. long. The modern holes are usually made by a f n will do the work without bendin slates or clays; but an ordinary atthe shank. Such drills can be used in „rill and hammer must be used in harder U1 w^ fhe roof is too poOT to hJld them. Such stations should be checked in they are used, if we wish to swear to the accuracy in the qu^ndary^of tl^man^vhose^^mpanyi worked ac^ossthSr liSe beSuse wood shoepeg is ci . d A cor q w m S oon rot, and, if m the plummet is tied to the lower for whip lashes , while the wire is S5r!Te™anSi! bu?fven this will be pulled out by catching in the topping 0f spads is dispensed with, and all the stations put in rock Lastly. a twist drill makes a vertical hole 1 m. deep, roof where poss b . ♦ ta ^ en the foresight man puts a steel clip with Int ° h ^?es Thf is made by bending upon itself a thin piece of steel serrated edges. This is mane d to | ether it w m go into the hole, and & in. wide. -When the senas are ^esse^ -js hold the clip in the hole so that the spring of the sides the ® through a hole in the center of the it is hard to pul] out oord^passes tnmi *gu a _ no matter how the clip bend and is, ^ d pressing together the ends of the clip. This is is inserted. ]t remov ea uy p | in | as the re is no eyehole to be freed the easiest and Q nc ] e . s V a L d ld un ti e d The hangingof the plummet from dirt and no knot to be tied and manea. f n a | long as F the roof takes a fraction of !a ^^ n a Vthe pXng of the holes inclined .to the vcTc Jbyl careleS mamand the many roofs that are unfit for pierc.ng with a twist drill ho , l]d hav e some regular way pf witnessing our Marking St • vertical line on the rib calls attention to a station m stations. I" general, ^vert o f station has the mark around it. as has the floor newthe sirte marKea. * jc fl e If three regular corps are been described a ^it ^s som g the same mine s, a s the company engaged m the ^“.tgi^ividual operator, and the private corps that is corps, the : corps i of : the nm p of the land owners, they must use The most common are the circle, square, and STATIONS. 59 triangle. If the “ circle ” corps puts in the station, it has a circle about it. The next corps uses it and puts a square about it and notes “ Sta. 472 = to Sta. 742 of ( ) Corps.” The third corps uses it and puts a triangle about the square, and notes “ Sta. 617 = to Sta. 472 of ( ) Corps, and Sta. 742 of ( ) Corps*.” If the first corps uses the station again, it notes the numbers given by the two other corps, and these three numbers will aid in identifying it if one or two of the numbers are lost. Distinguishing Stations.— Each station must be lettered or numbered so that it can be readily recognized when the subsequent surveys are made. When set it may have been^at the end of a gangway, while six months later the gangway has been "driven hundreds of feet from that place, chambers have been turned off in what was solid, and the place be so utterly unlike its former state that nothing but a fixed mark belonging to that station alone will enable us to recognize it. The methods of distinguishing stations vary widely. In one place the writer found that each gangway and room had a Station 1 at its beginning, and the various stations numbered 1 were designated “ Grog Run 1, 2, 3, etc.”; “ Pat James Gangway 1, 2, etc.”; and so on through the map, that showed between fifty and one hundred stations numbered 1, so that a new engineer would have had to learn the mine thoroughly before he could extend a survey. Another way is to use Al, A2, etc., up to A100, and so through the alphabet to avoid running up too high in numbers. A third was lettering the various sections of the mine A, B, C, etc., and the numbers begin with 1 in each and run up indefinitely. All of the above have disadvantages, as powder or lamp smoke, mud, mold, or the misplaced ingenuity of small boys may so obliterate or obscure a mark that it will be recognized only by association with its immediate neighbors, and these may have shared the same fate. You may have only a part of the mine map with you, and because the system of marking strives to get along with as few symbols as possible, you have to go to the office, when there would have been a chance of deciphering the mark if there had been a number of figures to it. The best practice, therefore, courts large numbers, begins with Station 0 at the mouth of the slope or drift, or the foot of the shaft, and numbers consecutively in each bed. In a short time three figures are reached, while in old mines the numbers require four digits. The chances of obscuring such a mark are lessened, while the chances of our deciphering it are increased. Centers.— When the station is in the roof, there must be something for the transit to set over, as it is easier to do so than to set under a station, and much more accurate as instruments are now made. The set-up is made over a “ center.” At first, a cross scratched on the floor or on a loose piece of slate, a daub of white lead on the same with a small piece of coal placed under the point of the plummet — when that had been steadied— or finally, a nail driven into a block and afterwards pointed, were used. All of these, except where the mark was on the solid floor — if they were large, enough co be stable— were in the way of the observer’s feet, while, if small, they were so light as to be readily displaced. It must be noted here that it is not so much the errors that we can foresee and detect that influence the accuracy of the work in our own eyes, but the chances of error from accidents that we cannot control and that cannot be readily detected. To avoid the above chances, we make the centers as small and as heavy as we can— in other words, we make them of lead. A hole If in. in diameter and i in. deep is bored in a thick plank, a brad is set in its center with the head down; the hole is filled with melted lead and the brad is slightly raised to surround the head with lead, and held with pincers in a vertical position till the lead has set. The brad is cut off I in. above the lead and pointed. This ’‘center” combines weight and small size, and is generally used. Paint.— White lead, or Dutch white, thinned with linseed oil, is ordinarily used. It is carried in a covered tin pail holding a pint. The cover nas a hole large enough to admit the brush. The pail generally has to be cleaned out after each day’s work, as the brush gathers dirt every time it is used. In case the paint is to be kept for a number of days, it must be covered with water, which can be poured off before using. If the ordinary paint brush has too long bristles, it can be shortened and kept from wearing by winding with fine wire to the proper length. The top should be wiped clean and dry with a piece of cotton waste before the paint is applied, or the white will be so discolored as to be scarcely visible, or if the top is dirty it will flake off, and the numbers be lost. 60 SURVEY NOTES. KEEPING NOTES. Taking Note,— Complete no^e^shoul<^be^teten^a^d^recor^dneatly^i^ Every ledge of rock should ibe noted , its “ a separate book for transit note s^an'd for ^denotes, andwhere many collieries are operated, a separate set of books should be f or ■ Jgc: ^Sterile' following things: The However the to check the vernfer, the numbers of the stations, the MJ 1 distance measured, either flat or on vernier reading, the dip ot tne si gnu f the ground; the height of the dip; the height ot the axis ot _thetramnt Necessary remarks to l^eight'of Srumelt), H. R- (hci^hl of tod, or poml to which sight was taken), .^^^^starting a survey, there should he entered the At the top of . g tQ be done; the na mes of name of the mme work and those that were taken from the the regular corps employed f O“he wotk, ai used . the date of the work, mine to point out work or assist; thyn^mmenlsuseo u e where such and, in case it he the ° S uch hooks are^complete records, and work was noted must , oe set -down Such boo«a e g P fg of the kind of Xkdon1in a 4seTlawsuit “quires Inch testimony by showing the number of men, the instruments "^“^hetam«eE^toy of keeping these Transit and Side Not . es -~P e ^ a ^^ P thods arrange themselves into groups, an^spec\mens of foS^oups will be shown, as the most common in use m the ^j s T-The side notes of each sight follow the transit notes of that sight, V»v the side notes in the same hook. Y Fourth. — Each set of notes has a separate hook se ts o£ The last method is *ke best-^en “ t X same time, such a method is notes, and where two men .do • the ^^^g^ate^et of hooks for ordinary imperative. Each mine should have a f t P ara "f y ;f the engineer reference work and special work, and |^c a pract^c a | d if the party ma kes surveys notes m a portable form. Unless tms ’ succee dmg surveys m any in twenty different n^^es^ the no f t bQth must be carr i e d. This ssars?a ssus.ss'." looked up, and the -notes found. outside survey is secondary to the The taking of side nnderiTund work, of ordinary character, the instrumental work; while m unde , are built the s j de no tes. The lines of the survey are r skeletons upo hich ^ the forms for taking them side notes are therefore of the^ hi ig tbe underground work, so that the'mapper* can 6 reproduce themkith fu 11 y even if he may never have been inside. Qnrmose we are setting up at 6; with backsight at „• &ht = ffiP 27' left; and that the drstance b e is 421.76 ft. measured on a pitch ol + 4 50 . First Form: Sta. Needle. B. S. S 25° 30' W Vernier. Needle. F. S. Pitch. Dist. Sta. A B L 85° 27' L 85° 26' S 60° 0' E + 4° 35' 421.76 c FORMS FOR NOTES . 61 Fig. 1. differences of level as measured filled in at the office, to make the This is read: “ Set-up at 6; backsight at a; foresight to c; first reading of vernier under A; second (check) reading under B; check reading by needle computed from foresight and backsight needle, etc.” Some note the readings of one vernier at A, and the opposite one at B, and take only one sight. The last column for stations is sometimes omitted, and the first widened, so that the three can be entered as fol- lows: “o-6-c.” Second Form .—' This differs from the first in having but one column for the venier reading, which is not noted until two readings agree, and also in omitting the last column for sta- tions, as noted above. In some cases the line is indicated by but two stations, the one set up at, and the foresight, as in the angle given above, b-c To note the backsight, the previous line is always taken, and under “Sta.” we put “a-5,” and the needle reading. Third Form . — In this case a continuous ver- nier is carried and the readings are put in the second column, with the needle course on foresights as a check in the third. In the column for stationsonly the station at which the set-up is made is noted on the line with the readings for that set-up — the backsight going on the pre- vious, and the foresight on the following, lines. Fourth Form . — This is also a form for record- ing a continuous vernier, as well as the deflected angle. The right-hand page is for noting by level or transit. Certain columns are book complete as a reference in mapping, or in the mine. This form is advocated “/or its compactness but there is such a thing as too much of that article, as there is no room on either page for remarks, while in all the other systems, the right-hand page is set aside for this purpose. Fifth Form .— Where the leveling is performed by the transit, and each sight is taken with that end in view, the level notes are added to any form of transit notes chosen and they are recorded as shown in table on page 56. These figures are used to calculate the differences in elevation, as shown by the pitch of the sight. The minus signs show that the points noted are below the stations. If the station were in the +5 * floor, the sight would have a plus sign. A contin- uous vernier can be used with this form. Forms for Side Notes.— In every case the notes should convey to the man that plots some idea of the form of the place surveyed. An accurate sketch cannot be made unless the whole locality can be seen at a glance— which is seldom, if ev6r, the case— and yet we must not go to the other extreme and write down the notes without a sketch; yet that is what is frequently done, and may be simply noted + $/ — 4 6 as the first form, and put aside as a faulty method with no good points. ♦ 72 — 5 7 Second Form — In this, see Fig. 1, as in a sketch made as a person advances with no definite idea of the arrangement of the work, there is too frequently is a running of the sketch off the page— on one side or the other, and a cramping of certain parts. Insert- ing the figures on the line of survey confuses the ;» one that plots if the sketch is distorted or cramped. As the hands of the note man are dirty from rub- bing along the tape, to find the numbers, it generally happens that the sketches are smeared and blurred ' so that they are hard to decipher when the notes Fig. 2. are most clearly kept, and a method that encourages cramping, confusion, or obscurity must be rejected. Third Form . — There is no attempt made at sketching in this form, Fig. 2, but the red line in the center of the page of the note book is taken as the line of survey, and the next parallel lines on either side are taken as the boundaries of the solid on either side. The only figures on each side of the red line are O 238 [167. + 157 — + /S? +Mo 4 I/O + 30 + 20 + 16 — » 5 + 14 0,23 r L LJ :n 62 SURVEY NOTES. thP distances from the line to the solid, while the “pluses” at which they were taken are noted at the side of the page, and the exact distance betw eei q ^ two stations is enclosed in the parallelogram. This method at the pluses 155 and 157 calls attention to a point where ^ a ^ c ^ e v ? r ^ e ' cans & tlmpUla^e^s to Sve|e 32SJ5J& .5 MX'SK corner as ttefirst ortart ^*X>f the ;^«id tm thi whethe^^at a ei^ e he < 10^or 100* ftf dSant.^ onVcan 1 %™^d”°n™tes^ W accurately taken, and two persons accurately plotting such notes will reach th \«^ Notes —These are kept as in outside work, as has been before stated iilssasssssa §gE| gfekSSHSSSs^SE proper degree. For rough measurements, the length of the winding rope bet By on^of these ^ mShodsw^lS'cate a bench mark below, that is connected ImUon^W^ must 1 bear In mind that roof stations are almost certain to kn Whenever we begin a level survey, we must measure the distance between roofand fkmr'and^e' it if agrees w& the notes . U» differs, we must note the fact under the original notes, as a check for future work. STOPE BOOKS. By Joseph Barrell.* Tn lare-e metal mines, where the veins are more or less vertical and great volumes of SI are Extracted from between the levels, it becomes important to fldoDt such a system for recording the shape and location of the stopes that at any P future time the engineers may he. able to give precise information coimeming them,^withou^ent e ^ng^tt^mine for^^m purjms^.^^ means for sketches Udth the transit work of the drifts and also the various Boors with one another othetical map of a portion of two levels Figs. 2, 3, and 4 ^Ksed^X^okl rilled %°t\e ^er^nically or #S ee “Mines and Minerals,” OctoDer, 1899 , page 97 , STOPE BOOKS. 63 fifth line to be heavier. Each square will represent a square set, giving an actual scale of about 20 ft. to the inch. A smaller scale does not show enough detail, and a larger one is not necessary for this class of work. The most convenient size for the bound books is 11 in. long by 5i in. wide. Only the right-hand leaves are numbered, so that when open a page extends entirely across the book, 20 in., showing 400 ft. of the length of the vein and wide enough for two floors on one page. The floors imme- diately above each other must follow on consecutive pages; thus, on the first double page will be 400 ft. of the sill floor and first floor, on the second page the second and third floors, and on the seventh page the twelfth and thirteenth floors. The eighth page is reserved for cross-sections of the vein, and the ninth for the long upright section, these two being shown by Figs. 3 and 4. The next 400 ft. of the same drift will be shown on page 10, so that it joins on to page 1 on one side and to page 19 on the other, and in this way the work of one level is kept together. For convenience, the book should be indexed by placing a projecting tag with the number of the level on each page of the drift floor. Having now a general idea of the arrangement of the work in the book, it remains for us to determine, precisely, how to place it and how to show the relation to the transit surveys. First, it is necessary to have some reference line on the vein. For this purpose draw on the map, through the center of the shaft, a line perpendicular to the strike of the vein, as shown in Fig. 1. Scale off from the map the distance at which it cuts the transit course from the nearest station. Then, by adding the known distances between sta- tions to this, we obtain the surveyed distance of apy point on the drift from our reference line. Select the middle or end of a page in the stope book for the zero or reference line, such that the drift will go most conveniently in the book, and on the upper line locate the survey points at their proper distances from it, as in Fig. 2. The vertical location of any part can be told when the dimensions of the tim- bering are known. In this instance the drift is 7 ft. 10 in. high, and each of the following 12 floors are 7 ft. 2 in. If the levels are exactly 100 ft. apart, the thirteenth floor will conse- quently be 6 ft. 2 in. in height. The Stope Book in the Mine.— Having indi- cated in the office, by a regular system, the place for everything that will be found in the mine, the next step is to proceed to the details of sketching. The location of the stations on the top line of the drift-floor pages shows on what vertical line they should lie in the sketch; but the fact that each square must be kept as representing a square set, and that any or all of them may not be exactly to our scale, will cause the location made in the mine to vary slightly from that made in the office. Any such discrepancy must be taken upon the edge ot the page. Therefore, proceed to the station nearest the center pf the pag© 64 UNDERGROUND SURVEYING. and locate it as nearly as possible under its position at the top, remembering tha/t the sets of timber, no matter how irregular, must be represented as Snares Now walk along the drift, watching the character of one side at the lino of the floor sketching while walking, counting the sets, and indicating the Posts bfdots of the plncil. Check up the number of sets on each station and Continue to the end of the drift. Sketch the other side in coming back, . , Aniinfing the sets a second time, from station to station, a further check y is"d 8 n^n the wort°On the ’correctness of the sketches of the dri Ha^inVhnihed h thedrilh'clfmb to theSr^floor and locate the set climbed through the same distance east or west of the reference line as °n the drift below g see Fig 2. Since the chutes and manways will ordinarily not step off PTonnd floor against tke hanging wall. It is well to start with 10, since then, t^cl^e'^^O'^is^^roi^lllan^toat^rtramines^e'Mmbering^nthe first SOOT On the thfrteen* floor, in this instance, as shown in Fig. 3, the man- wav is in row 19 In such a manner each floor is completely located with reference to the drift below and ultimately with the transit survey. The ease and rapidity of the work will depend on the character of the mine. Much is gained by practice, the work ™t being Knt q ruinsp for sketching being made ever> tittn or tenm sei, 01 wuwevei Sere a Change in the character of the wall. In drifts such as are usually ~ ® .ppr.™ q nfin t n q nm ft of sketching is a good day’s work. The sketch Should be tekenat^some^ definite horizon, and that of the floor level is best. Features of constant recurrence must be represented by conventional signs. Features ot constant ^ in Fi % c enclosed by a square indicates a chute passing through the floor; up means a ladder up; M, a manway down. A full line indicates a rock wall, a broken line, lagging; cross-hatching represents filling; a dashed-and-dotted line, the presumed limit of filled workings, etc. It is ot importance to indicate irregularities m the tim- bers. If it is a short set, write S within the square; if a long set, L, giving the length if necessary. If there should be an angle in the timbering so that there may be a set more on one side of the dntt than on the other, represent it by a wedge-shaped opening, as shown, being the appearance ot the drift if it were straightened out. In sketching, it is essential to accuracy that the attention be held to a few things at a time. On reaching the top ot the raise the plan views are completed, each floor having been sketched on the way up. On descend- ing - turn to page 8 and sketch the cross-section of +v»o rnflmvflv as shown in Fig. 3. Each set is still represented by a square, althOTgh the sets are higher than wide, but since that fact is known it can lea The stonebook is taken through the mine and brought up to date at the monih the tot &p Should have a notch cut in it and the same indicated in the Tki K i™„ Section -The view of the vein that will he of most general use, Fig. 3. THE LONG SECTION. 65 mine or the office, but it is a little better to determine the limiting points in the mine. The transit stations, chutes, and raises should, of course, be located upon it as common points with the map, connecting the two. The final long section is drawn by merely piecing together the several parts from the stope book and drawing them horizontally and vertically to the same scale. Since a vein is quite an irregular surface, the question arises as to what modification of a vertical projection will give the most accurate and con- venient representation of it. That devised by Mr. A. A. Abbott, of which the essential feature is the horizontal adjustment space left between the levels, is shown in Fig. 4. At our reference line, in this case the projection of the shaft upon the vein, the zero points of the levels are placed over each other. But owing to the warpings in the vein, a raise, such as No. 201, started, in this case, 40 ft. east, will not break through on the similar point of the level above. The simplest way in which to allow for these discrep- ancies is to draw the levels more than their true distance apart by the width of an adjust- ment space, lay out each level at its true length, and draw the raises perpendicular to them provided, of course, that the raises only step off along the dip and not along the strike. All these fea- tures can be appreci- ated by studying Figs. 1, 2, 3, and 4 in con- nection with each other. Lines corre- sponding to the height are ruled on the sides of the drawing, and the floor on which the work is being done is ascertained by means of a parallel ruler. Such a view approxi- mates to a development of the vein horizon- tally, but vertically to a projection , since the vein is projected on a series of vertical planes passing through the transit courses. The drifts are shown at their true lengths, but the heights are the vertical distances and not the lengths up the dip. The long section will be brought up to date every 3 or 6 months, and the portions of the veins extracted during the interval indicated by cross- hatching or tinting. In the illustration, the ore bodies are cross-hatched to bring them out more clearly, but to do this on the regular map would involve erasures with every extension in the workings. In 1 the mine, a hard and sharp drafting pencil will be used, but pencil markings in a book constantly in use soon become faint and blurred. It is necessary to go through the book at intervals and ink in everything with waterproof draw- ing ink. Two colors can be used with advantage, red for all transit lines and survey figures, and black for the stopes and those symbols relating to them. If there are several splits to a vein, sometimes worked together and sometimes not, the work on the different splits can be readily distinguished on the long section by using red for the hanging-wall split, and blue for that of the foot-wall. If old filling is taken out, such as ore, as frequently hap- pens, the parts extracted can be cross-hatched in red, and thus a record of both the first and second extractions preserved. The value of these methods over mere sketches made without system lies in their accuracy. Where the timbering is irregular, the accuracy of the results depends largely upon the time and care taken in the work. 66 UNDERGROUND SURVEYING. MINE CORPS. The method of dividing the work in an underground survey depends on the size of the corps. We will therefore consider the work of each man, in order to get the right number for the corps. The chief of the party should be where he can do the most good, and where he can plan the work for his subordinates. The principal point ot the survey is the setting 1 of the stations so as to do the work thoroughly with the fewest set-ups and thus diminish the chances of error in instrumental work. The chief should locate the stations and add all the necessary signs to show how the work is to be done. The transitman should not have his attention distracted from his particular work by questions as to procedure He should work untrammeled. The chief, therefore, should not run transit. Upon this basis the ideal mine corps works, and such a corps consists of at least four, and better five, men from the office .and three from the mine. It is divided into two sections. The chief takes the men supplied bv the mine— one or more of whom are acquainted with the work done since the last survey— and locates the stations; the transitman follows with the second section, to measure angles and distances. By this time the stations are set and the chief takes his men after the transit party and gets the side notes with a check measurement of the distances between stations. Such a corps goes to the end of the former survey and identifies the last two stations. The transitman prepares to set up at the last, while the chief and partv goes as far as he can see the light from the last station, or to some intermediate point from which one or more sights are to be taken. He then stops and sends a man along each place where a sight must be taken, as long as their lights are plainly seen from top to bottom where he is standing, and over this place he marks a point for a station to be inserted, and generally inserts it himself unless he be pushed by work, and must leave it for another to do when he places a circle about the dot, places the number at the side, and as many arrows as there are new stations, the longer arrow generally pointing to the sight to be last taken and where the transit is to y s be set up next. Leaving a backsight at the point just set, “ he sets, successively, stations at the points where the foresight men have stood, in the manner just described, until he has covered the new work— the mine boss or some intelligent miner going with him to give him an idea of the “lay of the ground,” so that the work can be covered with the fewest number of stations. Sometimes the chief takes the side notes and measures the distances between stations as fast as they are set. In a pitching place, a circu- lar brass protractor with small plummet is hung at the center of a stretched tape, to give the angle at which the tape is held; this serves as a check to the measurements of the transit party, which are taken as the basis of the work, and the other measurements are solely as checks. In flatwork, both measurements should coincide. In a small corps, and where time is of little importance, the foresight man puts in the stations ahead of the transit, and while he is so doing the transitman takes the side notes. Sometimes the side notes are taken by the Se man whill one of the party is taking the transit to the next station and setting it up for the next sight. There are about as many variations from these two methods as there are corps. . r . The foresiaht man should be intelligent and active, as the amount of work done in a day depends on his ability to keep ahead of the transitman. Some of the latter are fast enough to keep two foresight men on the jump. His duty is to set the center for the next set-up under the station, and also place the tripod if three are used in the work, to give the sight and, in some corps, to carry the front end of the tape and assist in taking the distance. In some corps he also carries the bag with tools for setting stahons, so that he gen- erally has a load that makes rapidity of movement difficult and anything that will diminish the weight carried will tend to quicken the work. The raDiditv with which good work is done varies considerably, but it depends on the activity of transitman and foresightman, and a good corps should have no trouble in making twelve set-ups an hour and taking two or three sights from each set-up It vanes also with the distances between stations. The saving of time should never be sought at the expense of accuracy in the work; it is to be gained by rapidity of moving about, in SURVEYING METHODS. 67 setting transit, center, etc., and in hanging plummets to give sight. The foresight man and backsight man should be in position to give sight before the transitman is ready, so that he can turn his instrument on one or the other and find them in position. The slowest parties were those that carried empty powder kegs (in the days when loose powder was allowed inside) for seats, and spent the greater part of the time sitting on them. The backsight man has little to do inside, and to compensate for this, he is the one that cleans and oils the tape, gets out new plummet strings, and sees that the tools are ready for the next work, as soon as the corps gets to the office. The transitman cleans the transit, unless the corps has subordinates that can be trusted with so delicate an instrument. The blackening from sulphureted hydrogen is rubbed from the silvered surfaces with whiting, and the oil or paint smears are removed with alcohol. Alcohol should be used instead of water for cleaning the instruments, and especially the lenses, which are wiped with jewelers’ cotton or soft chamois skin. SURVEYING METHODS. Outside Surveys.— We have spoken of the points necessary to include in the survey outside, and how the base line is established. It remains to call attention to several points that must be known before the surface plant can be protected from settling, from the removal of the deposit below. The exact location of all buildings, lakes, ponds, rivers, railroads, etc. is not only necessary for the making of a correct map; it is necessary for the determination of the amounts and location of the beds that must be left untouched by the subsequent mining. Here must be mentioned an error that generally governs the location of the retaining pillars to support the above and prevent damages to themselves or to the mine. The settling of the ground would make all bodies of- water leak into the mine, and also destroy to a greater or less degree all surface plant, as well as throw out of plumb all shafts or other openings for hoisting, if it did not close them entirely. The usual custom is to extend vertical planes through the bound- ary lines of such objects, and leave untouched all parts of the superincum- bent beds embraced by those planes. This is accurate only when the strata are horizontal or vertical, as beds settle normally to the planes of the strata and not in a vertical line in case the open spaces are stowed. If the spaces are left open, they are first filled by falls, and then the settling goes on according to the above rule. No cut is necessary to show the method of settling, and the place where the bed is to be left untouched may be found as follows: Draw a vertical section through the point to be supported , and also the underlying bed on the line of the dip of the bed— the section being accurately drawn to any scale. Draw through the extremities of the object to be supported, lines to the bed, which will make right angles with it. The space included will give the dimension of the pillar measured along the dip of the bed, and the dimensions of the object taken at right angles to the first plane will give the other dimension of the pillar. Inside Surveys.— As the beds of anthracite lie at all angles with the hori- zontal plane, the methods of surveying them vary accordingly, and can be divided into flat and pitching work. Flat work is where the beds have so slight a dip that the cars can be drawn to the face of the room, and where there is nothing to prevent a sight to that face from the gangway. The variations in the methods of work in this case depend on the accuracy with which the work must be performed, as, in some cases, the workings are approaching the boundary line of the property, and the sides of the rooms must be located accurately. In general, the rooms are driven at right angles to the gangway, unless the dip is too great to haul a car to the face on that line, when they are inclined to the gangway at an acute angle. The width of the rooms in fiat work is generally uniform where the roof is good, but where the roof is poor the entrance is harrowed for a short distance (to better support the gangway) and then widened to the full width, or the whole is driven to the limit narrow, and the side is robbed when the top is drawn, and the whole room caves in. This last must be surveyed before the robbing begins. The most accurate method of survey is to run a line along the gangway and put a station at the entrance of each room, whence a sight is taken to the face. This may be varied by putting the stations at alternate rooms 68 SURVEYING and measuring through the cross-cuts to get the thickness of the pillars of the intermediate rooms, or placing stations at every third room and measur- ing the thickness of pillars and width of rooms that intervene; or, finally, by running out the gangway with as few sights as possible and paying no atten- tion to the positions of the rooms in setting stations, thence up to the last room to the face, and back through the cross-cuts nearest the face to the former work, where a tie is made. When opportunity offers, sights are made from the face of the rooms to the stations in the gangway for immediate ties. In case a gangwav and airway have been driven considerably ahead of the rooms, it is always necessary to run lines out each and tie at the last cross- cut. This must be done in every case where the gangway is approaching the boundary line, or old workings that have been abandoned and are full of water! In addition to this check the miners must keep bore holes 20 ft. ahead in the line of the gangway, and every 20 ft. must drive others from the corners of the heading at an angle of 30° with the line of the gangway. In this way there will be no danger of running into “a house of water, as the Cornish miners call it, if the survey be inaccurate. Pitching Work.— When the bed pitches so that a car cannot be run to the face and when there is a good deal of firedamp in the mine, it is generally difficult to see from the gangway to the face, where the roof is good and the room straight, as a buggy track or chute, or both— when the pitch is slight fill up the room, and, where the pitch is great, the gangway pillars generally run across the face, or there is a “battery” shutting off the bottom of the room so that the face can be reached only by several sights. Where the roof is poor, the obstructions are increased, as the rooms are driven narrower or if wide, have center props and stowing m the center. If the coal is full of slate or if the partings are thick, a large part of the room is taken up with piles’ of “ gob,” and with a very poor roof the body of the room that has been worked out is filled with the fallen roof, and the coal sent out through the triangular man wavs, where it is almost impossible to take a sight. ^ Work of this kind is surveyed by lines out gangway and back through the faces of the rooms which are generally clear, even if the bodies of the rooms Se filled with the fallen top. Where chance favors sights are taken to the aangwav; but this very seldom happens, as the two lines are as effectually seoarated as if in different mines. From the stations in the faces, lines are run down the rooms as far as possible to get their direction and to locate the cross-cuts The very worst case of all is where two l^eds are separated hv a thin nartina of rock and the gangway is driven in the lower one alone, roomr in ^ the upper one being worked by rock chutes into the rooms below, or into the chutes from those rooms. This °f work is hard o ventilate and to survev where the rooms above are ventilated by the air lystem ohhe lower beds; but is readily mapped where there is an air system f ° r niosL b Iurvev.s,-To diminish the chance of error and to furnish a ready check the survey must be closed upon itself or some part of a former sur ye> withe^ryuvllvenew stations. With good work the error close Should not exceed 1', and the error m position shouMbe ^ectffied bv Errors must not be “balanced they must be detect® d a id rectified Dy running the line again, if they are not readily sejen *0™ must be given. If an incorrect survey be balanced, each su ^doeot one m altered to fit this ‘incorrect work, though it may aI ^ he cf never know where our work really stands. It well, tbeT ^^ the work in arc as soon as we make a close and before the party leaves me place, as it is easy to rerun the work then. CONNECTING OUTSIDE AND INSIDE WORK THROUGH SHAFTS AND SLOPES. As the dip of the bed increases, it is less easy to make % connection and the chances of accuracy diminish. In a survey, B. ^ 0 ^-^”f t fc aneu)ar locates the station with regard to former work The greatest angular accuracy for a given value of R is where T er^. ffn^ — O and ^ cosine Angle. As the pitch or vertical angle of sight increases, the above cosine diminishes until, at a vertical sight, R. Cos. vert.. Anf lko~+ [ u n mi difficulty In the case of an adit level, or a slope of less than 45 , there ^ no diffic y bevond the want of absolute rigidity m setting up the transit, and the danger of moving it in going about it. The difficulty increases mo e p > SHAFTS AND SLOPES. 69 than does the pitch, and as R. Cos. Vert. Ang. diminishes, though R be fixed, the chances of error increase. When the slope reaches 60° there is an impracticability in running a line down a slone, as the lme of collimation of the telescope strikes, the graduated limb of the instrument. We can use a prismatic eyepiece and see up the slope; but cannot look down. As we have assumed that it is unnecessary to use an additional telescope, we shall have to run the line by intermediates. Set up at the bottom of the slope where the longest sight up the same can be secured and backsight on a station of the underground work; or set a backsight for the occasion (both stations will afterward be connected with the work below). With the prismatic eyepiece, sight up the slope on a line that will give the longest sight and, at the same time, afford a good intermediate place to set up the transit, as, on a pitch of 60° or more, it is absolutely necessary that the legs of the transit should be set solidly (in holes in the floor, or between the sills of the track) so that they will not be moved by subsequent walking about it. By this method, all the sights will be taken from one side alone, and the tripod legs can be shortened to make the sight possible without building a standing place— if the man be short-legged. Call this station A; at the foot of the slope locate B, where the transit can be readily set up, and as far up the slope as we can see (this distance must be at least 100 ft. ), and in a continuation of A B, locate C. Set up at B and take foresight to C\ locate D under the same conditions that governed the placing of B, and, in a continuation of the line B D, place E. Set up at with foresight at E, and locate F and G as before. The survey is carried by the intermediates B, D, F, etc., to the top, by a series of foresights to C, E, G, etc. Shafts.— The term shaft in American coal-mining practice is applied only to vertical openings, though in metal mining, both in this country and abroad, it is also applied to highly inclined slopes. For such shafts, most of the methods given in the textbooks are worthless, as they are for transit work and R. Cos. Vert. Ang. in rare cases may be as great as 20 ft., while R varies from 100 to 1,500 ft. Again, to sight down a shaft necessitates the erection of a temporary (and therefore more or less unsteady) support for the tripod of the transit, and the chances of variation in its position as we stand on different sides of it are so great that we cannot feel sure that a movement has not taken place that will vitiate the work. In sighting up a shaft of greater depth than 100 ft., there is annoyance— if not danger — from dripping water or the fall of more solid substances. In a wet shaft the object glass is instantly covered with water, and a sight is impossible. We must also have a platform to stand upon, and we cannot feel sure that this will be perfectly rigid. From all these considerations the methods with a transit are never used by engineers in the anthracite regions, and the connections are made as follows: When the bottom of the shaft can be reached by an adit or slope in a roundabout route of such length as to render errors in measurement of dis- tance of great importance, the angles are carried by a transit with as long sights as possible, and no distances are measured, from a point on the surface in the shaft to a point vertically below it in the mine. Sometimes the guide of the cage is taken when it has been recently set, as the guides are plumbed into position; but the better way is to suspend an iron plummet by a copper wire: sink the former in a barrel of water so as to lessen the tendency to swing on account of the pull upon the “ bob ” and wires from the air-cur- rents, or falling drops in a wet shaft. The top of the barrel is covered with two pieces of plank with a semicircular groove of 3 in. radius cut out of the middle for the passage of the wire, to catch the substances whose fall upon the water would cause waves. The heavier the plummet and the lighter the wire, the less the tendency to swing. This wire can be sighted at by parties above and below at the same time, and the swing can be bisected to get the position of the wire. A number of sights that agree can be taken as accurate. When the shaft is the only way to get below from above, it must be plumbed with two or more wires suspended as just described. With two wires, they are so hung that an instrument can be set up below in a line passing through them produced, and at a sufficient distance from them to insure an accurate sight; with more wires, the station below can be located at any point whence all the wires can be seen. Case 1. — Two wires are used, which are located as far apart as possible. Two pieces of scantling c d and ef, Fig. 1, are spiked across the opposite corners of two compartments of a shaft to allow the cages to pass up and down 70 SURVEYING. e 401 * in - = 200 ft * in - 2 X o To Find the Radius of a Circular Railroad Curve, the Straight Portions of a Road Being Given.— If Q I and PD, Fig. 3, are the straight portions that are to be connected, the radius of the curve ID may be found as follows: Produce Q I and P D until they meet and form the angle T. Bisect the angle Q TP by the line T C. From the point on either line from which the curve is to begin, in this instance making the point I the point of curve, erect the line I C perpendicular to Q T, and the point where this joins the line T C, or C , is the center of the curve, and the line I C is the radius. To find the end of the curve, or point of tangent, as D, draw a line from C, perpendicular to TP. The line CD will also be a radius of the circle of which I D is the arc, and the point D will be the point of tangent. To Find the Radii of Compound Curves to Join Two Straight Portions or Road. This kind of curve is adopted where the railroad is required to pass through given points, as C . , D, P, P, Fig. 3 ( b ), or to avoid obstructions. Compound railroad curves are composed of straight lines and circular arcs, and have common normals, O H, O P, P I. Q J , K R. and therefore com- mon tangents where the arcs are joined. The normals are perpendicular to the straight portions of the road also; OH is perpendicular to A B E F is perpendicular to QJ and K R. 80 SURVEYING. To find the radii 0 B, C Q, Fig. 3 (c), to connect two straight lines of rail- road, AB, D E, the road has to pass from the point B, through the point C , and to touch the straight road E F at any point D. Join B and C, make the angle B CO = 0 B C, which is supposed to he given, equal 90° — TB C. Draw B 0 perpendicular to AB, then OB = CO , and is the radius of the arc B C. With OB as radius, describe the arc B C; draw C F perpendicular to C Q, and produce DE to meet it in F; make DF = CF\ and draw D Q perpen- dicular to E F , to meet C Q in Q. Then CQ -= Q D, and the radii 0 B and 0 D are determined. Practical Method of Laying Out Sharp Curves in a Mine.— Curves m a mine are usually so sharp that they are designated as curves of so many feet radius, instead of as curves of so many degrees. Suppose that it is required to connect the two headings A and B, Fig. 4(a), which are perpendicular to each other, with a curve of 60 ft. radius. Pre- pare the device shown in Fig. 4 (6), by taking three small wires or inelastic strings f g, gh, and g k, each 10 ft. long, and connecting one end of each to a small ring, and the other end of two to the ends of a piece y. 00 '? ^ 3 . long. Form a neat loop at the end / of the string#/. To use this device, lay off on the center line of the heading B, c d and d e equal to 60 ft. and 3 10 ft., respectively. Place the loop / of the device described over a small wire peg driven in at e, and the ring g over a similar peg at d. Take hold of the stick h k, pull the strings g h and g k taut, and place the center mark on h k on the center line of the heading B. Drive a small peg in at m, located by the point k, which is on the curve. Move the device forward, place the loop / over the peg at d, the ring g over the peg at m, and take hold of the stick h k and pull until the strings g h and g k are Fig. 4. taut, and the strings f g and g h are in a straight line. The point A: will fall on the curve at n, which mark by driving in a peg. To locate other points, proceed exactly as in the last step. The distance c d in any case is found by the formula c d = R tan £ J, in which R is the radius of the curve, and I the intersection angle of the center lines of the headings. HINTS TO BEGINNERS. Abuse of Instruments.— Surveying instruments of value and precision are not made of cast iron, as one would think from the way they are frequently handled. Underground work is transacted in places dark, dirty, and con- fined, so that extra care must be observed to prevent accidental knocks that damage the instrument even if they do not destroy its accuracy. STADIA MEASUREMENTS. 81 As it frequently happens that long distances must be traversed under- ground in going between the shaft or slope and the workings to be surveyed, the transit and level should be carried so as to obviate all accidents. They should never be attached to the tripod and carried on the shoulder, and, if the route to be passed over is up or down a slope or working place, the person carrying the instrument should be the last to descend and the first to ascend, so that loose stones or dirt that may be dislodged will not affect or endanger the instrument or trip the carrier. Be sure that the tripod head is tightly screwed on to the tripod. The writer remembers a case where the transitman and himself, when new to the work, spent over an hour in endeavoring to obtain two readings of an angle that would agree. The variations— from 8' to 2°— were caused by the slight movement of an old instrument with too much “ lost motion,” and a loose tripod head. A great many engineers prefer kerosene to fish oil for their lamps. Kero- sene never drops upon your book to make an unsightly smear, and perhaps obliterate part of your notes. A kerosene lamp is hotter and, with the glazed mine hat, is more apt to produce headaches. The writer, during the latter part of his underground work, wore a straw hat, had a piece of thin sheet brass riveted to its front with a hole in the top for the lamp hook. To the lamp was brazed a narrow cross strip of the same metal, and the strip ends, bent back upon themselves, were slid down the sides of the plate on the hat and kept the lamp from swaying. With such an arrangement it is not necessary to remove the lamp to read the vernier, and when the lamp is used, for other purposes, the hat can be removed with the lamp fastened tcb it. This arrangement keeps the hands free from lamp smoke or oil, and a cleaner note book is the result. When there is an antipathy to a lamp upon the head, and when, with a long, wooden handle, one or both hands are free in going about the work, a larger lamp is used of “torch” pattern, employed by wheel testers or engineers in railroad practice. Kerosene can be burned in this. The handle can be tucked under the left arm while taking side notes. Such a lamp is convenient in finding old stations in a high place, when there is no firedamp. For plumbing wet shafts, kerosene resists the extinguishing power of water better than fish oil, and is less readily blown out by a strong ventilating current. It makes more smoke, and, in tight headings, or mines with poor ventilation, with a large party, fouls the air much more readily than fish oil. Sometimes a mixture of the two is burnt in very drafty places, where it is ham to maintain a light. Kerosene is burned in the plummet lamp unless it is used with the “ safety ” attachment. Sweet oil, or any oil burning without smoke, must then be used. Smoke clogs the openings in the gauze, restricts the entry and escape of gases, and, especially if the gauze be damp with oil, may ignite and communicate the flame from within to the outside body of gas. White lead or Dutch white (white lead and sulphate of baryta in equal parts) is best for painting stations. Zinc white has been tried with less success. The mixture should not contain too much linseed oil— especially in wet places— or it will run and destroy the witness. THEORY OF STADIA MEASUREMENTS. By Arthur Winslow.* Late Assistant Geologist, Second Geological Survey of Pennsylvania, State Geologist of Missouri. The fundamental principle on which stadia measurements are based is the geometrical one that the lengths of parallel lines subtending an angle are proportional to their distances from its apex. Thus if, in Fig. 1 (a), a represents the length of a line subtending an angle at a distance d from its apex, and a' the length of a line, parallel to, and twice the length of, a subtending the same angle at a distance d' from its apex, then d' will equal 2d. * Mr. Winslow’s calculations and tables have been proved practically correct by the several corps of the Second Geological Survey of Pennsylvania. The corps in the anthracite regions, under directions of Mr. Frank A. Hill, geologist in charge, took over 30,000 stadia sights, and better results were obtained when tie surveys were made than in previous work in which distances were chained. 82 SUR VEYINO. This is, in a general way, the underlying principle of stadia work; the nature of the instruments used, however, introduces several modifications, and these will be best understood by a consideration of the conditions under which such measurements are generally made. There are placed in the telescopes of most instruments fitted for stadia work, either two horizontal wires (usually adjustable), or a glass with two etched horizontal lines at the position of the cross-wires and equidistant from the center wire. A self-reading stadia rod is further provided, gradu- ated according to the units of measurements used. In a horizontal sight with such a telescope and rod , the positions of the stadia wires are projected upon the rod, and intercept a distance which, in Fig. 1 (b), is represented by a. In point of fact, there is formed, at the position of the stadia wires, a small conjugate image of the rod that the wires intersect at points b and c, which are, respectively, the foci of the points B and C on the rod. If, for the sake of simplicity, the object glass be considered a simple biconvex iens, then, -by a principle of optics, the rays from any point of an object converge to a focus at such a position that a straight line, called a secondary axis, connecting the point with its image, passes through the center of 'the lens. This point of intersection of the secondary axes is called the optical center. Hence, it follows that lines such as c C and b B in Fig 1(b) drawn from the stadia wires through the center of the object glass will intersect the rod at points corresponding to those that the wires cut on the image of the rod. From this follows the proportion: d _ a ~v ”T- d = j- a, (1) where d = distance of rod from center of objective; . p == distance of stadia wires from center of objective; a = distance intercepted on rod by stadia wires; I = distance of stadia wires apart. If p remained the same for all lengths of sight, then y- could be made a Fig. 1. desirable constant and d would be directly proportional to a. Unfortunately, however for the simplicity of such measurements, p (the focal length) varies with the length of the sight, increasing as the distance diminishes and vice versa. Thus, the proportionality between d and a is variable. I he object, then, is to determine exactly what function a is of d and to express the rela- tion in some convenient formula. The following is the general formula for biconvex lenses: i + ? = 7 : (2) f is the principal focal length of the lens, and p and p' are the focal distances of image and object, and are, approximately , the same as p and d, respectively, in equation (1): Therefore, j ^ = y, approximately, d d and p f L a a From (1), Whence, •** I ~ f L d = -j- a + /• (2) STADIA MEASUREMENTS. 83 In this formula, it will be noticed that as / and I remain constant for sights of all lengths, the factor by which a is to be multiplied is a constant, and that d is thus equal to a constant times the length of a, plus/. This for- mula would seem, then, to express the relation desired, and it is generally considered as the fundamental one for stadia measurements. As above stated, however, the equation ~ = — is only approximately true, and the conjunction of this formula with (2) being, therefore, not rigidly admissi- ble, equation (3) does not express the exact relation.* The equation express- ing the true relation, though differing from (3) in value, agrees with it in form, and also in that the expression corresponding to -- is a constant, .and that the amount to be added remains, practically, /. The constant corre- sponding to -j may be called fcf, and thus the distance of the rod from the objective of the telescope is seen to be equal to a constant times the reading on the rod, plus the principal focal length of the objective. To obtain the exact distance to the center of the instrument, it is further necessary to add the distance of the objective from that center to/; which sum may be called c. The final expression for the distance, with a horizontal sight, is then d = k a -f c. (4) The necessity of adding c is somewhat of an encumbrance. In the stadia work of the U. S. Government surveys, an approximate method is adopted in which the total distance is read directlv from the rod. For this method the rod is arbitrarily graduated, so that, at the distance of an average sight, the same number of units of the graduation are intercepted, between the stadia wires on the rod, as units of length are contained in the distance. For any other distance, however, this proportionality does not remain the same; for, according to the preceding demonstration, the reading on the rod is propor- tional to its distance, not from the center of the in- strument, but from a point at a distance “ c ” in front of that center, so that, when the rod is moved from the position where the reading expresses the exact distance, to a point say half that distance from the instrument center, the reading expresses a dis- tance less than half; and, at a point double that dis- tance from instrument cen- ter, the distance expressed by the reading is more than twice the distance. The error for all distances less than the average is minus, and for greater dis- tances, plus. The method is, however, a close approx- imation, and excellent re- sults are obtained by its use. Another method of get- ting rid of the necessity of adding the constant was devised by ' Mr. Porro, a Piedmontese, who constructed an instrument in which there was such a combination of lenses m the objective that the readings on the rod, for all lengths of sight, were exactly proportional to the distances.:}: The instrument * This is demonstrated later on. t k is dependent on /, and can therefore be made a convenient value in any instrument fitted with adjustable stadia wires. It is generally made equal to 100, so that a reading on the rod of 1' corresponds to a distance of 100' -f /. } A notice of this instrument will be found in an article by Mr. Benjamin Smith Lyman, entitled “ Telescope Measurements in Surveying,” in “Journal Franklin Institute,” May and June, 1868, and a fuller description is contained in “ Annales des Mines,” Vol. XVI, fourth series. 84 SURVEYING. was however, bulky and difficult to construct, and never came into SflS^SlSIiS mmmm. the rod. In Fig. 2 (&)., A B = a = reading on rod; _ . t. r TT . up = d == inclined distance = c + GF = c + k. CH, jfP — j) = horizontal distance = d cos n; pp = Q = vertical distance = D tan n = vertical angle; AG B = 2m. and the sines of the opposite angles, AF sinm . GUF = sin [90° + \n — m)Y or, AF = G-Fsinm cos ( n — m ) 9 and B F GF sin m iET[90° — (w+m)]’ 1 or, p p = (? p sin m or cos (n + m)’ iP-(- JSP = an< ^ G F — y tan m C II cos m 2 sin m By substituting and reducing to a common denominator, C TT r».os m f cos ( n_ + m ) + cos ( n — rrrf J a T “i" cos (»+"»») cos (n — m) Reducing this according to trigonometrical formulas, cos 2 cos 2 m — sin 2 n sin 2 m CH = cl as d = c + ka cos n cos 2 m d = MF=c + k. CH. cos 2 n cos 2 m — sin 2 n sin - m cos n cos 2 m The horizontal distance, D = d cos n. . 2 F) = c cos n + k a cos 2 n — kci sin- n tan m. IOST4 1- fcUWD-i* — . , , .. The third very small even for long g s ^^t0 07'V TlSeforeiThe final formula for ffiSTX “?adir Aeld%%°cauf, and with Wires equidistant from the center wire, is the following: cosB + O * cos , n , ( 5 ) STADIA MEASUREMENTS. 85 The vertical distance Q is easily obtained from the relation: Q = Dtann. .*. Q = c sin n + a k cos n sin n\ or, Q = c sin n + a Jc . (6)* With the aid of formulas (5) and (6), the horizontal and vertical distances can be immediately calculated when the reading from a vertical rod and the angle of elevation of any sight are given. From these formulas the stadia reduction tables following have been calculated. The values of a A; cos'" n sin 2 n and a k — - — were separately calculated for each 2 minutes up to 30° of elevation; but, as the value of c sin n and c cos n has quite an inappre- ciable variation for 1°, it was thought sufficient to determine these values only for each degree. As c varies with different instruments, these last two expressions were calculated for three different values of c, thus furnishing a ratio from which values of c sin n and c cos n can be easily determined for an instrument having any constant (c). Similar tables have been computed by J. A. Ockerson and Jared Teeple, of the United States Lake Survey. Their use is, however, limited, from the fact that the meter is the unit of horizontal measurement, while the eleva- tions are in feet. The bulk of the tables furnishes differences of level for stadia readings up to 400 meters, but only up to 10° of elevation. Supple- mentary tables give the elevations up to 30° for a distance of 1 meter. For obtaining horizontal distances, reference has to be made to another table which is somewhat an objectionable feature, and a multiplication and a subtraction has to be made in order to obtain the result. Last, but not least, these tables are apparently only accurate when used with an instrument whose constant is .43 meter. The many advantages of stadia measurements in surveying need not be dwelt on here, both because attention has been repeatedly called to them and because they are self-evident to every engineer. Neither will it be within the compass of this article to describe the various forms of rods and instruments, or the conventionalities of stadia work. It is seen that, in the deduced formula, the factor by which the reading on the rod is multiplied is a constant for each instrument. The question now arises, Does this remain the case with a compound objective ? In view of the difficulty of demonstrating this mathematically, it was decided to make a practical test of this point with a carefully adjusted instrument. The readings were taken from two targets set so that the sight should be horizontal, thus preventing any personal error or prejudice from affecting the reading. A distance of 500 ft. was first measured off on a level stretch of ground, and each 50-ft. point accurately located. From one end of this line, three successive series of stadia readings were then taken from the first 50-ft. and each succeeding 100-ft. mark. The following table con- tains the results: Distances. Feet. Spaces Intercepted on the Rod. 1st Series. Feet. 2d Series. Feet. 3d Series. Feet. Mean. Feet. 50 .485 .4860 .4855 .4855 100 .985 .9870 .9830 .9850 200 1.985 1.9860 1.9840 1.9850 300 2.989 2.9875 2.9870 2.9878 400 3.983 3.9800 3.9890 3.9840 500 | 4.985 4.9850 4.9900 4.9867 Multiplying the mean of these readings by 100, and subtracting the result from the corresponding distance, we obtain the following table: *The above demonstration is substantially that given by Mr. George J. Specht in an article on Topographical Surveying in “ Van Nostrand’s Engineering Magazine,” February 1880 though enlarged and corrected. ’ 86 SURVEYING. Distances. Feet. Mean of Stadia Readings Times 100. Feet. 1 Differences. Feet. Variations From Mean. Feet. 50 100 200 300 400 500 48.55 98.50 198.50 298.78 398.40 498.67 1.45 1.50 1.50 1.22 1.60 1.33 | + .02 + .07 + .07 — .21 + .17 — .10 r> nr «• 1 AQ Stun of differences = 8.60; mean of difference - 1.43. The variations between the 4^ft Ting oSy^Tft. & A 3SS ^SbteSsaaSBraeffleas* is a constant value t P wone having a compound, plano-convex taken that m * settii ig th< 3 s0 set that the reading, at any dis- ment constant and mat tne ires am0 unt of this constant. f tance, is less tton tiie ■ true d: ish a uy* h distances and elevations onlfaVS^^ -eragl height of the telescope ^^.^S^o^r^ere this method will be impracticable, and then^hemolieif procedure must be left to the^ud^^^^^^^ur^eyon If rod, and the difference between this as the case may be. used in sighting to the rod eit small that in a great deal of stadia This difference will ordniarily be so ^ma 11 | rod for the angle of work no reduction will he nece^ry. In sghtog TO t gt always be use d. B y depression or elevation, the center h measured For theoretical exact- this means an exactly continuous line is e “easure idistant fr0 m the ness it is necessary that the stadia wires shoui^ne d ^ tance read is for an angle°of elevatioVdifferin^ from the true one by an amount proportional to tte SSn«eir g hd S measurements. . The common errors o c f 1 ‘ff I JXng S a difference of a whole Sff, ”5 of .noth,,, on. .ho»M „ „ #This applies to an in S trument witli m 0 vable S ta column headed 6° opposite 18' in the series for thfrefore, when a^i 9 570° &S the expressi0lJ for ak cos 2 n when ak = 100; m ^ ^akco&n = 98.80 X 5.70 = 563.16. column to^e S 75 be a(Med ° C ° S ^ which> in this case > is found in the subjoined In a similar manner, the required difference of level is ~ 4 . (+10.91X5.70) +.08 - +62.27. One multiplication and one addition must be made in each case. It is to be noticed that, with the smaller angles, cos n in the expressions c cos n and c sin n may be entirely neglected without appreciable error For values of c, which differ from those given, an approSSate^^tlon ?wo I expre4o t ns+ amount of dlffer enee, may very easily be made in these 88 STADIA MEASUREMENTS. oOX Diff. Elev. sssasssssasssssssssssasass^sssssse dddGGSGS&SSSSftSSSSSSSSSSaSSSSSS. rH 00 rH a Hor. Dist. gsasssssssssasisff^sssssBSSs^iSSSffis 8Sl88'888’88S8SSSS£SSSSaSS*S** s *£ 8 Tf I> CJ | 1.23 8 Diff. Elev. asggeeasssssrtsaaas^gsssgJErffiassss 22^23SSSSSSSSSSSSSSSSSSSSSSSS5ft rH CO rH rH «? I Hor. Dist. gsgsaa^^5sssissassa§as35asgssss| ftftSSSfeSiSSiSSifeSSSiSSSSSSSSSfeaaSSSS i> © © CO p 1 8 Hor. Diff. Dist. 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II V © © rH II 8 rH II V 90 *s © OS Wq is © o .s Wq STADIA MEASUREMENTS. 8sssseessss^sssass'Wsss?§8ffisss$f|^ §§§gS§ggggggggggsggggggggggggjsg ss s sfflssssssaSBSsssssss i - ©CO<£>OSCOOCSi>i>i>t>i>i>i>i>t' SS 8 l> i> l> 1> t~ t> fe ^ s © oS 2i:5SSSS88SSg8888te8SBSSSSSS53Sffiq| o.2 Wp CQ CQ CQ VJ uv vv »>•> '•■•' >•■»■»■» »•» - ^rfrfcSddogggggggggggggggg^ggggggggg !s£ oS 0.2 W-Q o ^ CO tH |P Oj 5 nn »-j '•’j ». ■; - - “ ? -C ». liS^S^****^*** 88888888 ® 888 DO^I^r^iOQO^O^CCt-O^GOr-jiO t> CO CO CO C — I> 00 CO CO 05 05 O © © rH rH ■.-I^^^n/r/r/iYif/idnonffiCJOSOO 00 M CO 05 CO to O - ■ - -^. :n fiw SS§S§SfeS3S5^«S*5S5S5SSS5S5^85SsS5SSS58g8888aSSSaa b.2 Wfl Sdsaasasrissss ^SS8gS3£3: (M l> CO CO "'t COCKN ' ^ffl^ffiliyS8§8§§SSgSS8SS88gSg§gSSSgSS8S Q a ^^ggSSSgSSS8SSSgS8gSSS8gS8S8^^wS5 0.2 S3 p CO 05 50 rH £. CN 2 535S§3^la^^^a^^^a^8^8g8s' 888888 Ph 5SSgS5^8^SgSSoS^.SSS553S^^^3S?3@S?S Pp CO CO CO 00 CO CO I 0.2 «p ^ggsIa isasEgssasssgasaaaaftSSSss. 'Crcgg^SSSS.icd.duSwwtfssSsesSiBSSsssssssa ssa££8888888888 CO 00 GO 00 00 CO CO ( * feN^toMo^gsoggjjjsggSgSSgg^SSggSSSSSS 1.25 | 1.161 .461 1.151 ELEMENTS OF MECHANICS. 91 ELEMENTS OF MECHANICS. Only the elements of machines are here treated, as all machinery how- ever complicated, is merely a combination of the six elementary forms viz • the lever , the wheel- and axle , the pulley , the inclined plane, the wedqe and the screw; and these six can be still further reduced to the lever and the inclined plane. They are termed mechanical powers, but they do not produce force; they are only methods of applying and directing it The law of all mechanics is: The power multiplied by the distance through which it moves is equal to the weight multiplied by the distance through which it moves. Thus, 20 ilb. of power moving through 5 ft. = 100 lb. of weight moving through 1 ft. In the following discussion friction is not considered the idea being to give an elementary knowledge of the principles of the elements of mechanics. * Levers.— There are three classes of levers. They are: (1) power at one end, weight at the other, and fulcrum between; (2) power at one end fuicrum at the other, and weight between; (3) weight at one end, fulcrum at the other, and power between. The handle of a blacksmith’s bellows is a lever of the first class. The hand is the power and the bellows the weight, with the pivot between as the fulcrum. A crowbar as used for prying down top rock is a lever of the second class. The hand is the power, the rock to be barred down the weight, and the point in the roof against which the bar presses ^ the fulcrum. The treadle of a grindstone is a lever of the third class. The foot is the power, the hinge at the back of the foot is the fulcrum and the moving of the machinery is the weight. ’ A lever is in equilibrium when the arms balance each other. The dis- tances through which the power and the weight move depend on the comparative length of the arms. Let L represent power’s distance from the fulcrum (C), l the weight’s distance, and a the distance between power and weight; then, if L is twice l, the power will move twice as far as the weight. Substituting these terms in the law of mechanics, we have 92 elements oe mechanics. th e short* arm of The firs! actfoule lonTa™ of the second, Cd^so^nto the last. . . fniprnm be four times the distance from the If the distance from A to the fulcrum d m to B then a power of 5 lb. at A will lift 20 lb. at B. If the arms of the second lever 13 D r-a V A 5 ) E B 6 Fig. 1. ;ie aiuJia ^ are of the same comparative length, the 20-lb. power obtained at B will exert a pressure of 80 lb on E\ and if the third lever has the same comparative lengths this. 80 lh.at-E wiUlift 320 lb. at G. Thus, ^power ^ wei ght A will balance a weight of 320 id. ' EZX. ¥ 5 . ;«. .h. . r . Th. windlass is a common form. Thepower is^apphedto the the handle, and the short arm is the radius oi t ine ax Thiis Tis the fulcrum, Fc the long arm, and Fb the S^aiSSJSSSVSS' t. proportional » ti.i. «U1. « Have P :W : Fig. 2. Fig. 3. r : R. PR = Wr. Wr - Wr P = TT R ~ P ‘ RP RP W~—. r = ^ A train. Fig. 3, consists of a series of wheels and axles that act on one another on the principle of a compound lever. The driver is the wheel to which power is applied The driven , or follower, is the one that receives m'diorifrointhe driver. The pinion is the small gear wheel on the axle. , , , • If the diameter of the wheel A is 16 in and of the pinion B 4 m., a pull oi 1 lb applied at P will exert a force of 4 lb. on the wheel C ; if the diameter of C is 6 in., and of D 3 in., a force of 4 lb. on C e | f jn °£ will raise a E. If E is 16 in. in diameter, and F 4 tin., a force o amQunt ace0 rding to weight of 32 lb on F 2,m Jd The wright will only pass through A of the law of mechanics, jyyppr ^ P R R r R f ^_ P = p R"' " — rr f r" n : n" : : r'r" : RR'. v : v' :: rr'r" : RR'R". n n / n" = number of revolutions; ’ y v' = velocity or speed of rotation; r r' r", etc. = radii of the pinions; F 4 JB R' P", etc. = radii of the wheels. ELEMENTS OF MECHANICS. 93 The Inclined Plane. — In Fig-. 5 we see that the power must descend a dis- tance equal to A C in order to elevate the weight to the height B C; hence we have P X length of the inclined plane = WX the height of the inclined plane, or P : W : : height of inclined plane : length of inclined plane; or, p = w _ pi l l h sin a ™ !?• Find the. Weight Required to Balance Any Weight on Any Inclined Plane. Multiply the given weight by the sine of the angle of inclination. Thus, to find the weight required to balance a loaded car weighing 2,000 lb. on a plane pitching 18°, we multiply 2,000 by the sine of 18°, or 2,000 X .3090170 = 618.034 lb. Or, if the length of the plane and the vertical height are given, multiply the load bv the quotient of the vertical height divided by the length. Thus, if a plane between two levels is 300 ft. long and rises 92.7 ft., and the load is 2,000 lb., the balancing weight is found as follows: 6 92 7 2,000X— = 6 18+ . Case 1 .— To find the horsepower required to hoist a given load up an inclined plane in a given time, use the formula Fig. 5. | Load (in lb.) + weight of hoisting rope (in lb.) J ( vertical height X < through which the (load is raised (in ft.) }. 33.000 X time of hoisting (in minutes) Example. —Find the horsepower required to raise, in 3 minutes, a car weighing 1 ton and containing 1 ton of material up an inclined plane 1,000 ft. long and pitching 30°, if the rope weighs 1,500 lb. c The total load equals car + contents + rope = 2,000 + 2,000 + 1,500 = 5,500 lb. The vertical height through which the load is hoisted equals 1.000 X sin 30° = 1,000 X .5 = 500 ft. • H P = 5,500 X 500 _ 27 7 . . j-l. x . 33 ; 000 X 3 Case 2. — When the power acts parallel to the base, use the formula W x height of inclined plane = P X length of base. These rules are theoretically correct, but in practice an allowance of about 30 i<> must be made for friction and contingencies. The screw consists of an inclined plane wound around a cylinder. The inclined plane forms the thread, and the cylinder, the body. It works in a nut that is fitted with reverse threads to move on the thread of the screw. The nut may run on the screw, or the screw in the nut. The power may be applied to either, as desired, by means of a wrench or a lever. When the power is applied at the end of a lever, it describes a circle of which the lever is the radius r. The distance through which the power passes is the circumference of the circle; and the height to which the weight is lifted at each revolution of the screw is the distance between two of the threads, called the pitch ( p ). Therefore we have P X circumference of circle = W X pitch, or P : W : : p : 2 n r. Wp r P The power of lengthening the lever distance between the P : W : 2 7r r p the screw may be increased by or by diminishing the threads. Example. — How great a weight can be raised by a force of 40 lb. applied at the end of a wrench 14 in. long, using a screw with 5 threads per inch? W X * * = 40 X 28 X 3.1416. W = 17,593 lb. The wedge usually consists of two inclined planes placed back to back. (Fig. 6.) In theory, the same formula applies to the wedge as to the inclined plane, Case 2. thickness of wedge : length of wedge. ELEMENTS OF MECHANICS . Friction, in the other mechanical P°^rs, i^lft^each^ wTh^ wedge efficiency; in this it is essential, since, ou ^ in in the others the powder isappl^^ steady* force; in this it is a sudden blow, and is equal to the m °Tlie 1 pu He y is*shnply™nothCT v ^- pqf a sing^ TvllrlW a™ an y d a is e used to change the direction of toeforce^ ^ _ ty of p P = w. V = v‘ m Mnuahle Pullev — A form of the single pulley, Movable Kuney. we ight, is shown m %L e f ta“his one half of tlfe weight is sus- Srned by the hook, and the other half by the a,.-. .. laineu .““r thp ko We r is only one-half the rw??cth^^ ^Combinations of Pulleys SSTlM ^we S r ^Yatacef lto ofweight. \‘i) In Fig. 10, a power of lib. will in the 8 421 _ 9 _ Fig. 7. Fig. 8. Fig. 12. f-n e ll^re^resents the OTdi^ry^a^le^bloc^ used bymechK wtoch catTbe calculated by the continuous rope is used, a Rule.— In any combination of V ui ffV^ ™ fh mnra hie block as many times 'ing the load, not counting the free ma. has a tension K&5 t&SS.’S-ffwftS r-« r. a . - of voneys, p = W w = T P. Differential Pulley.— Fig. 13. 2 " w = 2 PR Fig. 13. FRICTION AND LUBRICATION. 95 In all combinations of pulleys, nearly one-half the effective force is lost by friction. Composition of Forces. — When two forces act on a body at different angles, their result may be obtained by the following rule: Rule .— Through a point draw two lines parallel to the directions of the lines of action of the two forces. With any convenient scale , measure off, from the point of intersection, distances corresponding to the magnitudes of the respective forces, and complete the parallelogram. From the common point of application, draw the diagonal of the parallelogram; this diagonal will he the resultant, and its magni- tude can he measured with the same scale that was used to measure the two forces. When more than two forces act on a body simultaneously, find the resultant of any two of them as above; then, by the same method, combine this resultant with a third force, and this resultant with the fourth force , and so on. FRICTION AND LUBRICATION. Friction. — Friction is the resistance to motion due to the contact of surfaces. It is of two kinds, sliding and rolling. If the surface of a body could be made perfectly smooth, there would be no friction; but, in spite of the most exact polish, the microscope reveals minute projections and cavities! We till these with oil or grease, and thus diminish friction. Since no surface can be made perfectly smooth, some separation of the two bodies must, in all cases, take place in order to clear such projections as exist on the surfaces. Therefore, friction is always more or less affected by the amount of the perpendicular pressure that tends to keep them together. The ultimate friction is the greatest frictional resistance that one body sliding over another is capable of opposing to any sliding force when at rest. The coefficient of friction is the proportion that the ultimate friction in a given case bears to the perpendicular pressure. The coefficient of friction is usually expressed in decimals; but sometimes, as in the case of cars and engines, it is expressed in pounds (of friction) per ton. The coefficient of friction equals the ultimate friction divided by the perpendicular pressure, and the ultimate friction equals the perpendicular pressure multiplied by the coefficient of friction. Thus, if we have a block weighing 100 lb. standing on another block, and it takes 35 lb. pressure to slide it, the coefficient of friction = x 3 0 5 ^, or .35. Table of Coefficients of Friction. Materials. Smooth, Clean, and Dry Plane Surfaces. Smooth Plane Sur- faces, Perfectly Lubricated With Tallow. Oak on oak .40 .079 Wrought iron on oak .62 .085 Wrought iron on cast iron .19 .103 Wrought iron on wrought iron .14 .082 "Wrought iron on brass .17 .103 Cast iron on cast iron .15 .100 Cast iron on brass .15 .103 Steel on cast iron .20 .105 Steel on steel .14 Steel on brass .15 .056 Brass on cast iron - .22 .086 Brass on wrought iron .16 .081 Brass on brass .20 Oak on cast iron .080 Oak on wrought iron .098 Cast iron on oak .078 Steel on wrought iron .093 The above coefficients are only approximate, for the coefficient will vary with the intensity of the pressure and the velocity, and also with the condi- tions of the atmosphere. But they are correct enough for practical purposes. 96 ELEMENTS GF MECHANICS. Thp friction of liauids moving in contact with solid bodies is independent nf thp nressure because the forcing of the particles of the fluid over the pro- the area of surface or contact. Coefficients of Friction in Axles. _ Axle. Bell metal Cast iron Wrought iron Wrought iron Cast iron Cast iron Wrought iron Bearing. Ordinary Lubrication. Bell metal .097 Bell metal .07 Bell metal .07 Cast iron .07 Cast iron .07 Lignum vitae .10 Lignum vitae .12 Lubricated Continuously. .049 .05 .05 .05 rnmmmm Frictional Resistance of Shafting- Let K = coefficient of friction; J “ re^hf^^ftSgTnWleys + the resultant stress of belts; H = horsepower absorbed; D = diameter of journal in inches; E = number of revolutions per minute. Then ’ Ordinary Oiling. Continuous Oiling. ... _ m R 9 v P V D- .0112 X PX D\ „ „ K = :S»5MXPXi)XP; .000000339 XPXPXPl As f rough approximation, 100 ft. of shafting, 3 in. diameter, making Friction,” under Vend- ^Friction of Mine Cers.-The Metier .of 'mine ^™s |0 “U^h mat^h ^^tto^heT^e^otdition of g the track and the lubrication are important factors in determimngthe^ requisites of good In this connection, we _may, however state some ol me U _ n dry ings should renewal 6 andso contracted that, while it may ^3^"^ ™t open by jarring or by being acer- dentally struck by as P ra £ ^tP^nS^f^ilinff wheels that are improvements onM^^^lS^^r^^ undoubtedly some annular oil chambers, and those ^th ended to a welfiubricated bearing is SgSS SK£i££^- «» '«■«> Wa \Vith d a view of adopting a sta ™ da * d ^number 6 of U years^fth different of W T ilkesbarre, Pa., experimented for a number oi years FRICTION AND LUBRICATION. 97 styles of self-lubricating wheels, and as a result of the experiments it adopted a wheel patented by its chief engineer, Mr. Jas. H. Bowden. Mr. R. Van A. Norris, E. M., Assistant Engineer, made a series of 989 tests with old-style wheels, some of which had patent removable bushings, and others annular oil chambers, and the Bowden wheel. The old wheels were found to be practically alike in regard to friction. All the wheels were of the loose outside type, 16 in. in diameter, mounted on 2} in. steel axles, with journals 5£ in. long. The axles passed loosely through solid cast boxes, bolted to the bottom sills of the cars, and were not expected to revolve. The table of friction tests shows the results obtained with both old- and new-style wheels, and is of interest to all colliery managers, inasmuch as the figures given for the old-style wheels alone are the most complete in existence, and, as stated before, they are good averages. Tests were made on the starting and running friction of each style of wheel, under the conditions of empty and loaded cars, level and grade track, curves, and tangents. The instruments used were a Pennsylvania Railroad spring dynamometer, graduated to 3,000 lb., with a sliding recorder, a hydraulic gauge (not recording) reading to 10,000 lb., graduated to 25 lb., and a spring balance, capacity 300 lb., graduated to 3 lb. All these were tested and found correct previous to the experiments. Most of the observations on single cars were made with the 300-lb. balance. The two types of “ old-style ” wheels have been classed together in the table. Each car was carefully oiled before testing, and several of each type were used, the results being averages from the number of trials shown in the table. In the experiments on the slow start and motion, the cars were started very slowly by a block and tackle, and the reading was taken at the moment of starting. They were then kept just moving along the track for a considerable distance, and the average tractive force was noted, the whole constituting one experiment. The track selected for these experiments was a perfectly straight and level piece of 42 in. gauge, about 200 ft. long, in rather better condition than the average mine track. The cars were 41£ in. gauge, 3* ft. wheel base, 10 ft. long, capacity about 85 cu. ft., with 6-in. topping. To ascertain the tractive force required at higher speeds, trips of one, four, and twenty cars, both empty and loaded, were attached to a mine locomotive and run about a mile for each test, the resistance at various points on the track, where its curve and grade were known, being noted, care also being taken to run at a constant speed. Unfortunately, only four of the “new- style” cars were available on the tracks where these trials were made. The remarkably low results for the twenty-car trips are attributed to variations in the condition of the track, and the fact that the whole train was seldom pulling directly on the locomotive, the cars moving by jerks, so that correct observations were impracticable. The hydraulic gauge was used for these twenty-car tests, and the needle showed vibrations from 1 to 4 tons and back. The mean was taken as nearly as possible. The gauge was rather too quickly sensitive for the work, and the Pennsylvania Railroad dynamometer was not strong enough to stand the starting jerks and the strain of accelerating speed. The tests marked “rope haul” were made on an empty-car haulage system, about 500 ft. long, with overhead endless rope running continuously at a speed of 180 ft. per min., the cars being attached to the moving rope by a chain, a ring at the end of which was slipped over a pin on the side of the car. The increase of friction on the heavier grades was due to the rope pulling at a greater angle across the car. Correction was not made for this angularity at the time, and the rope has since been rearranged, so that the correction cannot now be made. There were not enough curve experi- ments to permit the deduction of any general formula for the resistance of these cars on curves. The experiments on grade agree fairly well with those on a level, the rather higher values obtained being probably due more to the greater effort required in moving them, and the consequent jerkiness of the motion, than to any real increase in resistance. As the experiments on all styles of wheels were made in an exactly similar manner, the comparative value of the results is believed to be nearly correct, the probable error in each set of experiments, as computed by the method of least squares, varying from about 4$ for slow start and motion to 12$ for the rapid motion and twenty-car trips. Summary of Friction Tests on Susquehanna 98 ELEMENTS OF MECHANICS. o « •papeoq •Xjdrag; % f 6 u 4 o o •'jqSpjVi jo o^BjaaoJa,! •uotjotj^ oj ana uoj, aad aojo^ aAijonai, a> •UOlJOTJji oj aria J13 3 jad aoio^ aAijonax n 03 O •jfjiAnJf) oj ana aoio^ aAijonJi •.re q Jad aojo^ aAijoeJj, •Je[) jo jqSiaii ! 1 •jqSxaAV i jo aSejuaojaj; 1 ) • not jot j^ oj ana nox jad aojoa aAijoeax t •txoijotj^ oj ana -ITBO jad aoioj aAijoeix a •ijiAejf) oj ana aoio^ aAijoeajj •jeQ Jad aoaoa aAtjoeax •jeQ jo jqSiaAL 50C0^l>C050C0O H©iOH iH OK© Ol woo lOiOiOlO 8888 co oi co HSHSH5 lOHOO^ co O lO I> 1— 1 29 44 to r- >o or oi iO o cq CO CO Ol Ol T> lO rH 1> rH rH asss CO CO Ol Ol 1> iO rH 1> rH i—I OlOtOlO o co co go lO 00 co co of 9,000 9,000 COC00105000501. T^OOiOOOOOOlOlr-J Tj5coc4oio4o4^oo o CD CO ^ O CO iO CO -n|e« Ol t> CO O CO ^ 05 CO oco-^oiqfr-coo OCOiOCOCO-^OSCO ) w|o» 8§SSSS55^| o oi 05 0 t"; cooi oi «£<*£ “m O 05 CO CO CO O o o £3 05 CO tt uO iO CO CO CO CO oo co oi I o o o o o o , 33 aaaa 00 01 ofofofofofoioioi a> *55 0 * 'd a> I— H s, 1 c> O Ol CO CO o 05 o o_ 00 00 05 of OO o co cq iO cooing iO cf Ol H 1 * (MOO COlOO rH rH a 62 50 00 rH rH iO ' Ol o o Ol OiCO 1—1 rH o ooo si rr Ol Ol Ol^ of of of of 'tf ^r-H o3,d S o> b o SS&8J1 o Q 8 o o o c> J Ol OUO co iMfffi : 0*0** aj a> 43 43 < f-1 4^P d d d d rj d «®OOOp.H'H fe fe 4J '-p +3 ‘-0 "p p !l 1 1 § 1-i-i be be he be be he bp bp o3 c3 c3 g g g g g &&&SS&SS p»t>p»p*>>>> ^St®8888 P to iH T-t Ol Ol Ol Ol -Idddgddd “ooooooo ^OOOQOQQ •iaaaaasa a>a>£> be bo be be be be bp bp ggg.gggss a5a2ci3'Do < i ,< i ) p* p» p» > p* > >> 2 2 ^ S S S d<2d<2£ no iH o © © 00 r-l o O © „ „0©© "p p i-l r-f 1 -f -2 -2 xn of oq" CQ Cfi p P P 1 K d o3 w £ £ o o o ■i-iaS'" © o © © © hObCbCfaJDbO cd c3 ci ai c3 p p p p P © D D ® fi {> p* {> P* > Summary of Friction Tests on Susquehanna Coal Co.’s Mine Cars, April, 1889— ( Continued). FRICTION AND LUBRICATION. 99 0 W •papBoa 0 00 CJ 05 CJ ^ t- CO (M 00 co CO •uoijoua oj ona jbq aod ooaoa oaijobjx ococooo 005 co 55 CJ t— 1 1—1 H ^'05 rH 00 O CJ lO CO MHHH O •jCjiabj*) oj ona ooioa oaijobjx CO CO 05 CJ 05 05 T-l COCOCJCJ iH rH 3 1 9 w £ *jbq jod ooioa oaijobjx OCOCOOO 005 COO CJ rH iH iH 2,000 1,825 400 350 'JBQ jo jqSia^. a H 9,125 8,160 8,160 8,160 H 0 8,160 8,160 8,160 8,160 w H W H m & •jqSio^ jo aSBjuaojaa > m .4 00 00 co 00 CO J> Tf CO TJH 10 CJ CJ i-l rH rH H OS 0 CO CO CJ OiOH tH 1-H 1-i £ •notjoua oj ana nox aod oojoa oaijobjx CJ lOI> co CO 10 00 CO CO OlOlO 05 CO CJ tn 0 . ’UOTJOTJa oj ona jbo jod oojoa OAIJO'BJX d|m ci|=->Hei CO CJ O co IH CO CO Tf 1 CO CO 98 38 27 a W •jCjiabjo oj ona ooaoa OAIJOBJX CJ CJ CO 88^ •jbo aod OOJOa OAIJOBJX dim Ci|«H®* CO CJ O CO CO CO CO CO 000 GrfO CO lO rH 'JBO jo jqSiOA lO iO iO iO iO HrlrirlH 'ct< ^ ^ cjcj'cfcfcj 2.415 2.415 2.415 -M Oj H «HtHO o o--=» M u a) a> o © ©d3 oj os B CD to CO © © © &&& o o o d d d fH S_ cd cj O o T-( Tfl P3 d 9*9 9 d © © Sh P U f-i M H © © © © © t> Cl ^^88 "h 8 1— Ti— 1 | d d d “000 +3 '42 +3 1999 © © © © be be bo bo d d d ^ © © © © k > > > 88 CO CO ■..3 i'g : 3 ©,-*->* oj o d §§1 111 lOH O OO i-l O -t-T 4-T _r ?-i H ^ Cj Cj „ ■stg s r> ^ O ° 02 02 © © © be be be d d oj H H fH © © © > >> Total number of tests 100 ELEMENTS OF MECHANICS. Lubrication.— There is probably no factor that has a more direct bearing on the cost of production per ton of coal and ores than the lubrication o_ mine machinery and yet it is doubtful if there is another item connected with t^e operation of a mine less understood by owners, their managers, and e "fteira S pfants a Ire'equipped with boilers of the highest known efficiency; ® team P- stpam will heat the feedwater for heaters are used that, by utilizing boilers to the highest point. Mor • waste steam, will heat the feedwater for iern engines that will develop a horsepower ^^S^o^fsteama^e installed; bends, instead of elbows, are placed in steam^ndexhaust pipes, so that the friction and back pressure mav be deduced to a minimum In a word, everything is done in the equip- ment of a plant to secure economy in its operation. After all this is done, freauently a long step is taken in the opposite direction by the use of an oil unsuited to the existing conditions, and those m charge of the plant are led to believe that the lubrication is all that could be desired, simply because the ermines and machinery run quietly and the temperature of the bearings ^e^not^t^co^^^hirmingly high. The office of a lubricant is not merely to setfure^h^re^lt^but, primarily, to reduce friction and wear to a nnnimum; fnd an oil that will do this is the best oil to use, no matter what the price Pe Xv?eahze y th e e great loss in power due to the friction of wearing parts. r>np nf the greatest living authorities on lubrication writes. ° “ It ma v^probably he fairly estimated that one-half the power expended in the ^vJrSe case whether in mill, mine, or workshop, is wasted on lost work being consumed in overcoming the friction of lubricated surfaces. He adds g that Treduction of 504 in the work lost by friction has often been See As e o d ne y of m\“ S in°sta“h^ing the loss that will occur by the use of inforinr Oihripunts attention is called to two flour mills located m one ot the Middle 1 S^ate^OneoTthe plants was equipped with a condensmpngme and valves found to be properly adjusted and the engine working within Itfribuf edTo R ?ie ra bofltrs S °buT ^ “ c " ey ’ " “ to. inferior lubrica- Among tne expeiibeh ^ k power produced in excess of that iiisll (9) 6 W°^randTaV n §fXchXrTwhich is constantly doing more work per ^"idiere^^l^^ai^ele^S^o^danger^that^ought to r ® c . e ' ve t se ^9^P j 2“g^r WUMm ^it^m^t^ffieulMrfsm'article of this character, to do much more than FRICTION AND LUBRICATION. 101 point out the danger due to the use of inferior lubricants, leaving it to the purchaser himself to determine as to the intrinsic worth of the lubricants offered to him. In making his selection he would do well to consult with and heed the advice of some highly responsible manufacturer of lubricants who has given to the question, in all its phases, the most careful study, and who would most probably have the benefit of a wide experience in the applica- tion as well as the manufacture of lubricants. Some buyers have, to then ultimate regret, adopted, as a method of determining the merits of lubri- cants, a schedule of laboratory tests. Such a method is not only useless, but it is misleading to any one other than a manufacturer of lubricants, who makes use of it merely as a means of insuring uniformity in his manu- factured products, and not as a measure whereby to judge their practical value. Indeed, many oils can be very properly described by practically the same schedule of tests, and yet are widely apart when their utility for a given service is considered. . . As a general guide in purchasing cylinder oil for mine lubrication, it might be said that a dark-colored oil is of greater value, as a rule, than one that has been filtered to a red or light amber color, as the process of filtration necessarily takes from the oil a considerable percentage of its lubricating value, and at the same time the process is an expensive one. In short, if a light-colored oil is insisted upon, a high price must be paid for an inferior lubricant. As a word of caution, however, it would be well to add right here that irresponsible manufacturers frequently take advantage of the fact that the most efficient and best known cylinder oils are dark-colored, and endeavor, with more or less success, to market as “cylinder oil” products absolutely unsuited to the lubrication of steam cylinders, and that would consequently be expensive could they be procured without cost. For the lubrication of engine bearings, where modern appliances for feeding are used, an engine oil of a free running nature is best, as it more quickly reaches the parts requiring lubrication than an oil of a more sluggish nature. It, of course, must not be an oil susceptible to temperature changes, but must be capable of performing the service required of it under the most severe conditions, where an oil of less “ backbone ” would fail. Such an oil would also be suitable for the lubrication of dynamos, and should also give satisfaction where used in lubricating the cylinders of air compressors. Where the machinery is of an old type and loose-jointed, or when the bear- ings are open and the oil is applied directly to them by means of an oiler, an engine oil of a more sluggish, or viscid, nature is best. Perhaps of equal importance to the lubrication of power machinery must be considered the lubrication of the axles of mine cars. This is important, first, because of the fact that perhaps three-fourths of the oil used about a coal mine is used for this purpose, and, secondly, because there is really a marked difference in the quality and, therefore, in the efficiency of lubricants used for this purpose. Fully nine-tenths of the prominent railroads of this country are today using car-axle oil, costing perhaps as much per gallon as much of the so-called cylinder oil that is used in coal mines, they having discovered, by exhaustive experiments, that the increased efficiency gained bv using an oil of such quality many times offsets the difference in the cost per gallon and enables them to secure a greater mile- age without any increase in their power or other fixed charges. This, we are certain, would apply just as forcibly to the lubrication of coal cars, no matter whether the ‘power is derived from “long-eared mules” or electric motors, and we believe this feature of lubrication of mine equipment should receive more careful attention than it does receive, as a rule. There is a considerable amount of waste in the lubrication of mine cars. This waste is hard to avoid, and, naturally, makes the buyer hesitate before adopting the use of a car oil that costs very much per gallon; but we believe it can be demonstrated, even in the face of this waste, that the increased efficiency secured by the use of a high-grade car oil would warrant its use. Such waste is pretty hard to correct in mines where the old-fashioned style of car axles is still in use, and where the oil is applied through an ordinary spout oil can into the axle box, and allowed to drip off the axles and on to the ground. When axles are equipped in the same manner as those of freight cars, or where cars are equipped with one of the several different stylefc of patent car wheels and axles that are coming into use quite extensively, it is possible to regulate the feeding of the oil to the axles, so as to reduce the waste to a minimum. One of these patent car wheels, which is perhaps better known than any other, is constructed with a hollow hub 102 STRENGTH OF MATERIALS. that acts as a reservoir tor the oil, the oil passing from this reservoir through small holes onto a telt washer. which it must saturate, and by which n is applied to the axles. Such wheels require a limpid oil. as a heavy^ sluggish oil would not so readilv saturate the felt washer referred to. A tight cap is adjusted to the end of the axle, to prevent waste of oil. These wheels will run quite a length of time without reoiling after the reservoir is once filled. Of course, it costs something to equip mine cars with these patent axles, but we are convinced that such an outlay would result in more economical operation, particularly if at the same time the very best quality of car oil obtainable is used. BEST LUBRICANTS FOR DIFFERENT PU RPOSES (TH U RSTON). Low temperatures, as in rock drills driven by compressed air Very great pressures, slow speed Heavy pressures, with slow speed Heavy pressures and high speed Light pressures and high speed Ordinarv machinery - { oils. Steam cylinders - - - j Heavy mineral oils. lard, tallow. ( Clarified sperm, neat’s foot, por- Watches and other delicate mechanism. < poise, olive, and light mineral ( lubricating oils. For mixture with mineral oils, sperm is best; lard is much used; olive and cottonseed are good. STRENGTH AND WEIGHT OF MATERIALS Light mineral lubricating oils. Graphite, soapstone, and other solid lubricants. The above, and lard, tallow, and other gTeases. Sperm oil. castor oil, and heavy mineral oils. Sperm, refined petroleum, olive, rape, cottonseed. Lard oil. tallow oil. heavy mineral oils, and the heavier vegetable WOODEN BEAMS. To Find the Quiescent Breaking Load of a Horizontal Square or Rectangular Beam Supported at Both Ends and Loaded at the Middle. -Multiply the br^dth in inches bv the square of depth in inches, divide the product by distance in feet between the supports, and multiply the quotient by the constant given in the table on the next page. Take safe working load one-third of break- ing To°Find the Quiescent Breaking Load of a Horizontal Cylindrical Beam.— Divide the cube of the diameter in inches by the distance between the supports in feet, and multiplv the quotient by the constant. . . . , When the load is uniformly distributed on the beam, the results obtained by the above rules should be doubled. n . . , , . Example 1. — Find the quiescent breaking load and safe working load oi a yellow-pine collar 8 in. square. 12 ft. between legs. Breaking load = 8 X 500 — 21,333 lb. for seasoned, and 10,666 lb. for ^Saf^working load = 7.111 lb. for seasoned, and 3,556 lb. for green timber. Example 2.— Find the quiescent breaking load, and the safe working load of a hemlock collar 10 in. diameter, 7 ft, between legs. 103 . , OO, /1-i Breaking load = ^ X 236 = 33,714 lb. for seasoned timber, and = 16,857 lb. for green timber. 03 71 4 , 33,714 11.238 Safe working load = — = 11,238 lb. for seasoned, and - 6 or —j- = 5.619 lb. for green timber. _ _ , , . To Find the Load a Rectangular Collar Will Support When Its Depth Is Increased. When the length and width remain constant, the load vanes as the square ot the depth. IRON AND STEEL BEAMS. 103 Example —A rectangular collar 10 in deep supports 15,000 lb. What will it support if its depth Ans . Havin*r the Length and Diameter of a Collar, to Find the Diameter of a Longer Collar to Support the Same Weight.— For the same load, the strength of collars vanes as the cubes of their diameters, and inversely as their lengths. . Example —If a collar 6 ft. long and 8 in. diameter supports a certain weight, what must be the diameter of a collar 12 ft. long to support the same weight? ■ 0 . if 6 : f 12 : : 8 in. : 10+ m. Ans. Having the Loads of Two Beams of Equal Length and the Diameter of One, to Find the^Diameter Of the Other. — When the lengths are equal, the diameters vary as the cube roots of the loads, or the cubes of the diameters vary as the ^Example 1.— A beam 11 in. in diameter supports a load of 32,160 lb. What will be the diameter of another beam the same length, to support a load of 19,440 lb.? if 32,160 : if 19,440 : : 11 : 9. Ans. Example 2.— A beam 8 in. in diameter will support a load of 10,240 lb, What load will a beam the same length and 7 m m diameter support? vv 8 3 : 7 3 : : 10,240 : 6,860. Ans. Table of Constants. Calculated for seasoned timber. For green timber, take one-half of these constants. Safe working load is one-third of breaking load. Woods. Ash, white Ash, swamp Ash, black Balsam, Canada Beech, white Beech, red Birch, black Birch, yellow ... Cedar, white Chestnut Elm Elm, rock Hemlock Hickory Ironwood Square or Rectan- gular. Round. Woods. Square or Rectan- gular. Round 650 383 Locust 600 353 400 236 Lignum vitae 650 383 300 177 Larch 400 236 350 206 Maple 550 324 450 265 Oak, red or black ... 550 324 550 324 Oak, white 600 353 450 265 Oak, live 600 353 450 266 Pine, white 450 265 250 147 Pine, yellow 500 295 450 265 Pine, pitch 550 324 350 206 Poplar 550 324 600 353 Spruce ■' 450 265 400 236 Sycamore 500 295 650 383 Willow 350 206 600 353 1 To Find the Diameter of a Collar When the Weight Increases in Proportion to the Length —Find the required diameter to support the same weight as the short collar. Then the length of the short collar is to the length of the long one as the diameter found to support the original weight is to the required Example. — If a collar 6 ft. long, 8 in. in diameter, supports a certain weight, what must be the diameter of a collar 12 ft. long to support twice the weignt ? 1 : 2 : : — : 4^, or 1 : 2 : : 2 X 8 3 : ( ) 3 , 6 or 12 fl:if2 ::8f2 :( ) == 12.7. Ans. IRON AND STEEL BEAMS. Constants for use in calculating strength of iron and steel beams: Cast iron Wrought iron * 1 * Steel 5 000 Safe Loads Uniformly Distributed for Standard and Special I Beams. ( Tons of 2,000 Pounds. ) 104 STRENGTH OF MATERIALS. IH iOX 5 co CO c3 ©5 la o +-> fl £ ll •ft 5» bo bo m Oh H « 2 h a qaajl ui sjjoddng uaoAvjog; ooubjsiq; lO O 1 > 00 Cl o •;i[Bl0/W ui 0SB0JOUX •qi;‘lj0Aa; joj ppy 8 00 N 50 lO Tjt ^3 io to o t>- ic co >-i o oo i> io ^ co icj id lO TjH Tjn rj5 T}i cd CO CO CO CO •;qSi0AV ut osbojoui •qd ^J0A3 JOJ ppY 10X5 CO o CO © © ci $ 3 00 00 t> t> 50 50 coioioioiOiOTri '-^ '^i'^ •jqSiaAY ui 0 SB 0 JOUX •qq‘Xj0Aa joj ppY X N 50 lO ^ TjH CO CO C0 ©ooooi>i>t>i>cdco’co H 000101 CS 00 00 001 > qoa^ ui s^joddns u03Avj0a; aouB^sia lO CO f'- 00 Cl O rHCTCO'flOCONXCiO r-l iH m 1-1 1-t ( f x -°“) +1 when l = length in inches, b = breadth in inches, and d = depth in inches. Crushing Loads of Well-Seasoned American Woods. Wood. Ash Beech Birch Cedar, red Cedar, white Chestnut Hemlock Hickory Linden Locust, black, yellow Locust, honey Maple, broad-leafed Oregon Crushing Load. Lb. per Sq. In. 6,800 7.000 8.000 6.000 4,400 5.300 5.300 8,000 5.000 9.800 7.000 5.300 Wood. Crushing Load. Lb. per. Sq. In. Maple, sugar, black Maple, white, red Oak, white, red, black Oak, scrub, basket Oak, chestnut, live Oak, pin - Pine, white Pine, pitch Pine, Georgia Poplar Spruce, black Spruce, white Willow 8,000 6,800 7.000 6.000 7.500 6.500 5.400 5,000 8.500 5,000 5,700 4.500 4.400 For green timber, take one-half of the constants or crushing strength. Safe working load equals one-third of crushing load. ■ , -rvr,c+ Example 8 — What is the breaking load of a well-seasoned hemlock post 10 in. by 8 in. and 12 ft. long? 5,300+ [l + (^T X - 004 )] = 2,308.4 lb. per sq. in. of area. 2,308.4 X 80 = Tcf Find 'the Breaking Load of a Cylindrical Wooden load of a square prop whose ends are equal m area to those oi me cym drical one and proceed according to foregoing rule. . . Example.— W hat is the safe working load for a hemlock mine prop 10 m. dia The e area of the^nd of the prop = 78.54 sq. in. A square of equal area will have sides equal to 1/ 78.54 = 8.86+ in. Then, 5,300 + [l + X .004)] = 3,058.3 lb. per each sq. In. of area. 106 STRENGTH OF MATERIALS. And 3,058.3 X 78.54 = 240,198 lb. This is the crushing strength of a similar prop of seasoned timber, but, as mine timber is used in its green state, we take one-half of 240,198 lb., or 120,099 lb., as the crushing load of the prop in question. Then, the safe working load is one-third of this, or 40,033 lb. The strength of similar props varies as the cubes of their diameters, and inversely as their lengths. Safe Loads, in Tons of 2,000 Pounds, for Hollow Cylindrical Cast-Iron Columns. (The Carnegie Steel Co ., Limited.) Outside Diam. Inches. Thickness of Metal. Length of Columns in Ft. Sectional Area. Inches. Weight in Lb. of Columns per Ft. of Length. 8 10 12 14 16 | 18 20 22 24 Tons. Tons. Tons. Tons. 1 Tons. Tons. Tons. Tons. Tons. 6 £ 26.2 23.0 20.1 17.5 15.2 13.2 11.5 8.6 26.95 6 f 37.5 33.0 28.8 25.0 21.7 18.9 16.5 12.4 38.59 6 7 42.7 37.6 32.8 28.5 24.7 21.5 18.8 14.1 43.96 6 1 47.6 41.9 36.5 3i.8 27.6 24.0 21.0 15.7 49.01 6 1| 52.2 46.0 40.1 34.8 30.2 26.3 23.0 17.2 53.76 7 f 47.7 43.1 38.5 34.3 30.4 26.9 23.9 21.2 18.9 14.7 45.96 7 l 61.1 55.2 49.3 43.8 38.9 34.4 30.6 27.1 24.2 18.9 58.90 7 1} 67.2 60.8 54.3 48.3 42.8 37.9 33.7 29.9 26.7 20.8 64.77 8 2 57.9 53.3 48.6 44.1 39.7 35.8 32.2 28.9 26.1 17.1 53.29 8 l 74.6 68.7 62.5 56.7 51.1 46.0 41.4 37.3 33.6 22.0 68.64 8 1£ 89.9 82.8 75.5 68.4 61.7 55.5 49.9 44.9 40.5 26.5 82.71 9 f 68.1 63.6 58.9 54.2 49.6 45.2 41.2 37.5 34.1 19.4 60.65 9 l 88.0 82.3 76.2 70.0 64.1 58.4 53.2 48.4 44.1 25.1 78.40 9 H 106.6 99.6 92.2 84.8 77.6 70.8 64.4 58.7 53.4 30.4 94.94 9 U 123.8 115.7 107.1 98.5 90.1 82.2 74.8 68.1 62.0 35.3 110.26 9 H 139.6 130.5 120.8 111.1 101.6 92.7 84.4 76.8 69.9 39.9 124.36 10 1 101.4 95.9 89.8 83.6 . 77.4 71.5 65.8 60.5 55.5 28.3 88.23 10 H 123.3 116.5 109.1 101.6 94.1 86.8 79.9 73.4 67.5 34.4 107.23 10 1 £ 143.7 135.8 127.3 118.5 109.7 101.2 93.2 85.6 78.7 40.1 124.99 10 If 162.7 153.8 144.1 134.1 124.2 114.6 105.5 97.0 89.1 45.4 141.65 11 1 114.8 109.4 103.5 97.3 91.0 84.8 80.2 73.1 67.7 31.4 98.03 11 H 139.9 133.3 126.1 118.6 110.9 103.3 97.8 89.4, 82.5 38.3 119.46 11 U 163.5 155.9 147.5 138.6 128.7 120.8 114.3 104.1 96.4 44.8 139.68 11 1 $ 185.7 177.1 167.5 157.5 147.3 137.2 129.8 118.3 109.5 50.9 158.68 11 2 206.6 196.9 186.3 175.1 163.8 152.6 144.4 131.5 121.8 56.6 176.44 12 1 128.0 122.9 117.2 111.0 104.7 98.4 92.2 86.1 80.4 34.6 107.51 12 1£ 156.4 150.1 143.1 135.7 127.9 120.2 112.6 105.2 98.2 42.2 131.41 12 li 183.3 175.9 167.7 159.0 149.9 140.9 132.0 123.3 115.1 49.5 154.10 12 1$ 208.7 200.4 191.0 181.1 170.7 160.4 150.3 140.5 131.1 56.4 175.53 12 2 232.7 223.4 213.0 201.9 190.4 178.9 167.6 156.6 146.1 62.8 195.75 13 1 141.2 136.3 130.7 124.7 118.5 112.1 105.8 99.5 93.5 37.7 117.53 13 li 172.8 166.8 160.0 152.7 145.0 137.2 129.4 121.8 114.4 46.1 143.86 13 1£ 203.0 195.9 187.9 179.3 170.3 161.1 152.0 143.1 134.3 54.2 168.98 13 W 231.6 223.6 214.5 204.7 194.4 183.9 173.5 163.3 153.3 61.9 192.88 13 2 258.9 249.9 239.7 228.7 217.3 205.5 193.9 182.5 171.3 69.1 2x5.56 14 1 154.3 149.6 144.3 138.5 132.3 125.9 119.5 113.1 106.8 40.8 127.6C 14 1 £ 189.2 183.4 176.9 169.7 162.2 154.4 146.5 138.6 131.0 50.1 156.31 14 1 £ 222.6 215.8 208.1 199.7 190.8 181.7 172.3 163.1 154.1 58.9 183.67 14 If 254.4 246.7 237.9 228.3 218.1 207.6 197.0 186.5 176.2 67.4 21C.0G 14 2 284.8 276.2 266.4 255.6 244.2 232.4 220.6 208.8 197.2 75.4 235.12 15 1 167.4 162.9 157.8 152.1 146.0 139.7 133.3 126.8 120.4 44.0 137.28 15 1£ 205.5 200.0 193.7 186.7 179.3 171.5 163.6 155.7 147.9 54.0 168.48 15 1£ 242.1 235.7 228.2 220.0 211.2 202.1 192.8 183.5 174.2 63.6 198.74 15 If 277.2 269.8 261.3 251.9 241.9 231.4 220.7 210.1 199.5 72.9 227.45 15 2 310.8 302.5 293.0 282.5 271.2 259.5 247.5 235.5 223.6 1 81.7 254.90 j SPECIFIC GRA VITY. 107 Minimum Safe-Bearing Values of Masonry Materials. Materials. Tons per Sq. Ft. Granite, capstone Squared masonry Sandstone, capstone Squared masonry Rubble, laid in lime mortar Rubble, laid in cement mortar Limestone, capstone Squared masonry Rubble, laid in lime mortar Rubble, laid in cement mortar Bricks, hard, laid in lime mortar Hard, laid in Portland cement mortar Hard, laid in Rosendale cement mortar ... Concrete, 1 Portland, 2 sand, 5 broken stone 50 25 25 12 5 10 36 18 5 10 7 14 10 10 SPECIFIC GRAVITY, WEIGHT, AND PROPERTIES OF MATERIALS, ETC. The specific gravity of a body is the ratio of its weight to the weight of an equal balk of pure water, at a standard temperature (62° F. = 16.670° C.). Some experimenters have used 60° F. as the standard temperature, others 32° and still others, 39.1°. To reduce a specific gravity, referred to water at 39 1° F., to the standard of water at 62° F., multiply by 1.00112. Given specific gravity referred to water at 62° F., multiply by 62.355 to find the weight of a cubic foot of the substance. Given weight per cubic foot, to find specific gravity, multiply by 0.016037. . . _ Given specific gravity, to find the weight per cubic inch, multiply by 0. 036085. nd ^ Specific Gravity of a Solid Heavier Than Water.— Weigh the body both in air and in water, and divide the weight in air by the difference of the weights in air and water. Example.— A piece of coal weighs, say, 480 grains. Loss of weight when weighed in water, 398 grains. 1 , 000 . 1.206, specific gravity of the coal compared with water at As a cubic foot of water weighs, approximately, 1,000 oz., the weight of a cubic foot of any substance can be found by multiplying its specific gravity by To°°Fi'nd the Specific Gravity of a Solid Lighter Than Water.— Attach to it another body heavy enough to sink it; weigh severally the compound mass and the heavier body in water, divide the weight of the body in air by the weight of the body in air plus the weight of the sinker in water minus the combined weight of the sinker and body in water. To Find the Specific Gravity of a Fluid.— Weigh both in and out of the fluid a solid (insoluble) of known specific gravity, and divide the product of the weight lost in the fluid and the specific gravity of the solid by the weight of th ¥he weight of a cubic foot of water at a temperature of 62° is about 1 000 oz. avoirdupois, and the specific gravity of a body, water being 1,000, shows the weight of a cubic foot of that body in ounces avoirdupois. Then, if the magnitude of the body be known, its weight can be com- puted; or, if its weight be known, its magnitude can be calculated, provided we know its specific gravity; or, of the magnitude, weight, and specific gravity, any two being known, the third may be found. To Find the Magnitude of a Body in Cubic Feet From its Weight.— Divide the weight of the body in ounces by 1,000 times the specific gravity of the body. To Find the Weight of a Body in Ounces From Its Magnitude.— Divide the weight of the body in ounces by the specific gravity of the substance mul- tiplied by 1,000. . , , ., . ,, . Note— The specific gravitv of any substance is equal to its weight in grams per cubic centimeter. (See table of metric weights and measures.) 108 WEIGHT OF MATERIALS . Specific Gravity of Substances- Substance. Air, atmospheric; at 60° F. under pressure of 1 at- mosphere, or 14.7 lb. per sq. in. Alcohol, pure Alcohol, of commerce Aluminum Anthracite* coal - Asphaltum Brass, cast Brass, rolled - Bronze, gun metal " Brick, best pressed Brick, common hard Carbonic-acid gas Clay, dry, in lumps, loose Clay, potters’, dry ... - Coke, f loose, of good coal Coal, bituminous % Coal, bituminous, broken loose . Coal, bituminous, moderately shaken Copper, cast Copper, rolled Earth, common ioam, perfectly dry, loose Earth, common loam, perfectly dry, shaken ■■■•" Earth, common loam, perfectly dry , moderately packed Earth, common loam, slightly moist, loose Earth, common loam, more moist, loose Earth, common loam, more moist, shaken Earth, common loam, more moist, packed Earth, common loam, as a soft flowing mud Earth, common loam, as a soft mud packed Gold, cast, pure or 24 carat Gravel Gutta percha Gypsum (plaster of Pans) Gypsum, in irregular lumps Gypsum, ground, loose Gypsum, ground, well shaken Gvnsum, calcined, loose Hydrogen gas, 14£ times lighter than air and lb times lighter than oxygen Ice - Iron, cast Iron, rolled bars Iron, sheet Iron, wrought Lead - Lime, q uick - - • - - - • ■ — • ■ - v ■ - • • • * vr • Lime, quick, ground, loose, per struck bushel, 66 lb. Mercury, at 32° F. Mercury, at 60° F Mercury, at 212° F ■ ■ ; - Nitrogen gas, & part lighter than air Oils, whale, olive Average Specific ^ Gravity. ( Average Weight per Du. Ft. Lb. .00123 .0765 .793 49.43 .834 52.1 2.66 166.0 1.5 93.5 1.4 , 87.3 8.1 504.0 8.4 524.0 8.5 529.0 150.0 125.0 .00187 .1167 63.0 1.9 119.0 27.5 1.35 84.0 50.0 54.0 8.7 542.0 8.9 555.0 .25 15.6 76.0 87.0 95.0 78.0 80.0 90.0 96.0 108.0 115.0 19.26 1,204.0 98.0 .98 61.1 2.27 141.6 82.0 56.0 64.0 56.0 .92 7.21 7.65 7.77 11.38 1.5 13.62 13.58 13.38 .92 .00527 57.4 450.0 480.0 485.0 485.0 709.6 95.0 53.0 849.0 846.0 836.0 .0744 57.3 * Anthracite increases about 75 per cent, in bulk when broken to any market size. A ton ’“n'A^e^SeTSoolw&sfrom 35 to 42 lb, A «ou occupies « M» M -« ; «• 1 1 heaped bushel, loose, weighs about 74 lb., and a ton occupies from 43 to 48 o. ft. Bttumt nous coal, when broken, occupies 75 per cent, more space than in the solid. L - SPECIFIC GRAVITY. Specific Gravity of Substances— (Contin ued). 109 Substance. Oxygen gas, part heavier than air Petroieum Powder - Rosin Silver Slate Steel Sulphur — »—*••• Tallow cast Water, purej rain or distilled, at 32° F., Barom. 30 in. Water, pure, rain or distilled, at 62° F., Barom. 30 in. Water, pure, rain or distilled, at 212° F., Barom. 30 in. Water, sea, average - Zinc Average Specific Gravity. Average Weight per Cu. Ft. Lb. .00136 .0846 .878 54.8 1.5-1.85 105.0 1.1 68.6 10.5 655.0 2.8 175.0 7.85 490.0 2.0 125.0 .94 58.6 7.35 459.0 62.417 1.00 62.355 59.7 1.028 64.08 7.00 437.5 The following table gives the specific gravities of various coals: Name of Coal. Sp. Gr. Weight of a Cu. Ft. Lb. Weight of a Cu.Yd. Tons. Newcastle Hartley, England 1.29 80.6 .972 Wigan, 4 ft., England 1.20 75.0 .914 Portland, England 1.30 81.2 .978 Anthracite, Wales 1.39 86.9 1.047 Eglington, Scotland 1.25 78.1 .941 Anthracite, Irish 1.59 99.4 1.193 Anthracite, Pennsylvania 1.55 96.9 1.167 Bituminous, Pennsylvania 1.40 87.5 . 1.054 Block coal, Indiana 1.27 79.4 .956 SPECIFIC GRAVITY AND WEIGHT OF PREPARED ANTHRACITE COAL. To Mr. Irving A. Stearns, General Superintendent of the Pennsylvania Railroad Co.’s Coal Department, we are indebted for the following sum- mary of tests made by the mining engineers of the company. In a series of tests to ascertain the specific gravity of the coal from differ- ent seams worked by the company, it was found that the average specific gravity was 1.4784, and the average weight per cubic foot was 92.50 lb. This was calculated for space filled at breaker without settling. Add 5 °jo for packed spaces of large heaps. Weight per Cubic Foot of Susquehanna Coal Co.’s White Ash Anthra- cite Coal. Size. Size of Mesh. Weight peri Cu. Ft. 1 Pounds. 1 > Cu.Ft. Froml Over. Through. Cu. Ft. Solid. Lump Broken 4£" to 9 " 2f" to 2f ' 3i" to 4i" 57 53 1.614 , 1.755 Egg 11" to 2|" 2f" to 2£" 52 1.769 Large stove H" to H" 1 *" to 2i" 51* 1.787 Small stove 1 " to H" H" to H" 5H 1.795 Chestnut I" to V' 1 " to li" 51 I | 1.804 Pea I" to f" £"to 50* 1.813 No. 1 buckwheat xV'to f" f" to •50* 1.813 .No. 2 buckwheat T V'to §" 50* 1.813 110 WEIGHT OF MATERIALS. LINE SHAFTING. Shafting 1 is usually made cylindrically true, either by a special rolling process, when it is known as cold-rolled shafting oi it is turned u|p m a machine called a lathe. In the latter case, it is called bright shafting. What is known as black shafting is simply bar iron rolled by the ordinary process and turned where it receives the couplings pulleys, bearings etc Bright turned shafting varies m diameter by 4 m. up to about 3 2 in. m diameter; above this diameter the shafting varies by 2 in- Tiie actual diameter of a bright shaft is less than the commercial diameter it being designated from the diameter of the ordinary round bar iron, from whfch it is turned. Thus, a length of what is called 3" bright shafting is ° n ^Cold-roiied shutting is designated by its commercial diameter; thus, a leneth of what is called 3" shafting is 3 in. in diameter. Cold-rolled iron is considerably stronger than ordinary turned wrought iron* the increased strength being due to the process of rolling, which seems to° compreffi tho metal and so make it denser-not merely skin deep, but practically throughout the whole diameter. STRENGTH OF SHAFTING. D = diameter of shaft; jt = revolutions per minute; H = horsepower transmitted; C = constant given in table. Constants foe, Line Shafting. in the accompanying table the bearings are WPOsed to » excessive bending; also, in the third vertical col- umn, an average num- ber and weight of pulleys and power given off is assumed. In determining the constants given in the accompanying table, al- No Pulleys Pulleys Material of Shaft. Between Between Bearings. Bearings. Steel or cold-rolled iron 65 85 Wrought iron Cast iron - 70 9C 95 120 ii D 3 X R 1 ) = s 1C X H M R R = CXH H * Shafts are subject to forces that produce stresses of two kmds-transverse and torsional. When the machines to bedriven are below the shaft, there is a transverse stress on the shaft, due to the weight of the shaft itself, ■ nullev and tension of the belt. Sometimes the power is taken off horizon tally on one side, in which case the tension of the belt transverse stress, while the weight of the pulley acts with the shaft to produce a vertical transverse stress. When the machinery to oe driven is placed on the floor above the shaft, the tension of the belt produces a transverse stress in opposite direction to that due to the weight of the S ^^The torsional strength of shafts, or their resistance to breaking by. twisting, is nronortional to the cube of their diameter. Their stiffness or resistance to bending is proportional to the fourth power of their diameters, ^d inversely proportional to the cube of the lengths of their spans. No simple formula can be given that will sately apply to engine and other shafting that is subjected to the bending stresses produced by overhung cranks, the weight of heavy flywheels, the poll of large helts or to ^evere^shocks p - duced by the intermittent action of the power or load. The emulations 101 such shafts should always be based on the special conditions h In the following table is given the maximum distance between the bear ings of some continuous shafts that are used for the d^iwavs Pulleys from which considerable power is to be taken should always be Fen^hsof shafts composing a line of shaft- ing may be proportional to the quantity of power delivered by length. In this connection, the positions of the various pulleys depend WEIGHT OF CASTINGS. Ill on the distance between the pulley and the bearing, and on the amount of power given off by the pulleys. Suppose, for example, that a piece of shaft- ing delivers a certain amount of _____ power; then, it is obvious that the shaft will deflect or bend less if the pulley transmitting that power be placed close to a hanger or bear- ing, than if it be placed midway between the two hangers or bear- ings. It is impossible to give any rule for the proper distance of bear- ings that could be used univer- sally, as in some cases the require- ments demand that the bearings be nearer together than in others. If the work done by a line of shaft- ing is distributed quite equally along its entire length, and the power can be applied near the middle, the strength of the shaft need be only half as great as would be required if the power were applied at one end of the shaft. Diameter of Shaft. Inches. Distance Between Bearings. Feet. Wrought-Iron Shaft. Steel Shaft. 2 11 11.50 3 13 13.75 4 15 15.75 5 17 18.25 6 19 20.00 7 21 22.25 8 23 24.00 9 25 26.00 WEIGHT OF CASTINGS. To Find the Approximate Weight of a Casting.— For iron, multiply the weight of the pattern by 20. Copper is £ heavier; lead, f heavier; brass, £ heavier; and zinc is T % 7 334.0 i 372 411 450 530 609 30 74.2C > 112.00 1 150.00 1 188.0 l 227.0 i 266.0 i| 305.0 1 345.0 l 384 424 465 | 547 | 629 DIAMETER- AND NUMBER OF WOOD SCREWS. Formulas for Wood Screws. No. Diameter. No. Diameter. No.* Diameter. N = number 0 .056 11 .201 22 .347 I) =- diameter 1 .069 12 .215 23 .361 D - {NX -01325) + .056 2 .082 13 .228 24 ,374 D - .056 3 .096 14 .241 25 .387 N — .01325 4 5 .109 .122 15 16 .255 .268 26 27 401 414 6 .135 17 281 28 427 7 .149 18 .293 29 440 8 .162 19 ,308 30 453 9 .175 20 .321 10 .188 21 .334 114 WEIGHT OF MATERIALS. WEIGHT OF WROUGHT IRON. The following table is for wrought iron. Multiply by .95 for weight of cast iron; by 1.02 for steel; by 1.16 for copper; by 1.09 for brass; by 1.48 for lead. Thickness or Diameter. Inches. Weight of a Square Foot. Pounds. Weight of a Square Bar 1 Ft. Long. Pounds. Weight of a Round Bar 1 Ft. Long. Pounds. Thickness or Diameter. Inches. Weight . of a Square Foot. Pounds. Weight of a Square Bar 1 Ft. Long. Pounds. Weight of a Round Bar 1 Ft. Long. Pounds. 5.052 .0526 .0414 4f 176.8 64.47 50.63 1 10.10 .2105 .1653 4k 181.9 68.20 53.57 | 15.16 .4736 .3720 4f 186.9 72.05 56.59 20.21 .8420 .6613 4f 192.0 75.99 59.69 | 25.26 1.316 1.033 4f •197.0 80.05 62.87 f 30.31 1.895 1.488 5 202.1 84.20 66.13 7 _ 35.37 2.579 2.025 5f 212.2 92.83 72.91 l 6 40.42 3.368 2.645 5f 222.3 101.9 80.02 lj 45.47 4.263 3.348 5f 232.4 111.4 87.46 It 50.52 5.263 4.133 6 242.5 121.3 95.23 If 55.57 6.368 5.001 6f 252.6 131.6 103.3 1£ 60.63 7.578 5.952 6i 262.7 142.3 111.8 If 65.68 8.893 6.985 6f 272.8 153.5 120.5 If 70.73 10.31 8.101 7 282.9 165.0 129.6 If 75.78 11.84 9.300 7j 293.0 177.0 139.0 2 80.83 13.47 10.58 7i 303.1 189.5 148.8 2£ 85.89 15.21 11.95 7f 313.2 202.3 158.9 2f 90.94 17.05 13.39 8 323.3 215.6 169.3 2f 95.99 19.00 14.92 8i 333.4 229.3 180.1 2\ 101.0 21.05 16.53 8£ 343.5 243.4 191.1 2f 106.1 23.21 18.23 8f 353.6 247.9 202.5 2f 111.2 25.47 20.01 9 363.8 272.8 214.3 2f 116.2 27.84 21.87 9| 373.9 288.2 226.3 3 121.3 30.31 23.81 9f 384.0 304.0 238.7 3f 126.3 32.89 25.83 9f 394.1 320.2 251.5 3f 131.4 35.57 27.94 10 404.2 336.8 264.5 3f 136.4 38.37 30.13 m 414.3 353.9 277.9 3f 141.5 41.26 32.41 10k 424.4 371.3 291.6 3| 146.5 44.26 34.76 lOf 434.5 389.2 305.7 3f 151.6 47.37 37.20 ii 444.6 407.5 320.1 3f 156.6 50.57 39.72 ni 454.7 426.3 334.8 4 161.7 53.89 42.33 lii 464.8 445.4 349.8 41 166.7 57.31 45.01 iif 474.9 465.0 365.2 41 171.8 60.84 47.78 12 485.0 485.0 380.9 Spikes and Nails. Starn Length. lard Steel-Wire 1 Common. ST ails. Finishing. Steel-Wire Spikes. Common Iron Nails. Sizes. In. Diam. No. per Diam. No. per Length. Diam. No. per Size* Length. No. per In. Lb. In. Lb. In. In. Lb. In. Lb. 2d 1 .0524 1,060 .0453 1,558 3 .1620 41 2d 1 800 3d li .0588 640 .0508 913 3i .1819 • 30 3d li 400 4d li .0720 380 .0508 761 4 .2043 23 4d li 300 5d If .0764 275 .0571 500 4i .2294 17 5d If 200 6d 2 .0808 210 .0641 350 5 .2576 13 6d 2 150 7d 2i .0858 160 .0641 315 5i .2893 11 7d 2i 120 8d 2i .0935 115 .0720 214 6 .2893 10 8d 2i 85 9d 2f .0963 93 .0720 195 6i .2249 7i 9d 2f 75 lOd 3 .1082 77 .0808 137 7 .2249 7 lOd 3 60 12d 3f .1144 60 .0808 127 8 .3648 5 12d 3i 50 16d 3i .1285 48 .0907 90 9 .3648 4i 16d 3i 40 20d 4 .1620 31 .1019 62 20d 4 20 30d 4i .1819 22 30d 4i 16 40d 5 .2043 17 40d 5 14: 50d 5i .2294 13 50d 5i 11 60d 6 .2576 11 60d 6 8 WROUGHT IRON. 115 Weight, in Pounds, of 1 Lineal Foot of Wrought Iron— Flat. Multiply by .95 for weight of cast iron; by 1.02 for weight of steel; by 1.16 for copper; by 1.09 for brass; by 1.48 for lead. Size. Inches, Weight. Pounds. Size. Inches. Weight. Pounds. Size. Inches. Weight. Pounds. 1 X* 0.85 5£Xt 6.65 4 XI 8.45 ttx £ 1.06 5£ X 1 6.97 4£ X 1 8.98 U X J 1.27 5f X I 7.29 4£ X 1 9.51 if X £ 1.48 6X| 7.60 4f X I 10.03 2 X £ 1.69 5 XI 10.56 2£ X £ 1.90 i X£ 1.69 5£ X 1 11.09 2s X 4 2.11 *-4 X 1 2.11 5£ X I 11.62 2f X | 2.32 -*£j X ? 2.53 5f XI 12.15 3 X£ 2.53 If Xi 2.96 6 XI 12.67 3£ X £ 2.75 2 Xi ! ! 3.38 3£ X £ 2.96 2£ X 1 | -5.80 1 Xf 2.53 3f X £ 3.17 2£X£ 4-22 1£ X f 3.17 4 X£ 3.38 2f X £ 4.65 1£ X f 3.80 4£X£ 3.59 3 X£ 5.07 If Xf 4.44 4£ X £ 3.80 3£ X £ 5.49 2 Xf 5.07 4f X £ 4.01 3£ X £ 5.92 2£Xf 5.70 5 X £ 4.22 3f X £ 6.33 2£ X f 6.33 5£x£ 4.44 4 X £ 6.76 2f Xf 6.97 X £ 4.65 4£ X £ 7.18 3 X f 7.60 5f X £ 4.86 | 4£ X £ 7.60 3£ X f 8.24 6 X £ 5.07 4f X £ 8.03 3£ X f 8.87 5 X £ 8.45 3f X f 9.51 1 XI 1.27 5£ X £ 8.87 4 X f 10.14 1£ X | 1.58 5£ X £ 9.30 4£X f 10.77 1| X f 1.90 5f X £ 9.72 4£ X f 11.41 If XI 2.22 6 X £ 10.14 4f Xf 12.04 2 XI 2.53 5 X f 12.67 2£ X ! 2.85 1 XI 2.11 5£ X f 13.31 2i X 1 3.17 l£ X t 2.64 5£ X f 13.94 2f XI 3.49 1£ X 1 3.17 5f X f 14.57 3 XI 3.80 If XI ‘ 3.70 6 Xf 15.21 3£ X | 4.12 2 XI 4.22 31X1 4.44 . 2£ X ! 4.75 11X1 5.07 3f X 1 4.75 2£ X 1 5.28 2 XI 6.76 4 XI 5.07 2f XI 5.81 3 XI 10.14 4£ X 1 5.39 3 XI 6.33 4X1 13.52 4£ X t 5.70 3£ X 1 6.87 5 XI 16.90 4f X f 6.02 3£ X I 7.39 6X1 20.28 5 X | 633 3f X I 7.92 7. X 1 23.66 Strength of Metals in Pounds per Square Inch. Material. Ultimate Tensile. Ultimate Compres- sion. Ultimate Shearing. Modulus of Rupture. Modulus of Elasticity. Millions. Wrought iron 50,000 44,000 44,000 48,000 27 Shape iron 48,000 26 Structural steel j 60,000 65,000 52,000 52,000 60,000 29 Cast iron 18,000 81,000 25,000 45,000 12 Steel, castings 70,000 70,000 60,000 70,000 30 Brass, cast 24,000 *30,000 36,000 20,000 9 Bronze, phosphor 50,000 14 Bronze, aluminum 75,000 120,000 Aluminum, commercial 15,000 12,000 12,000 1 11 * Unit stress producing 10 $ reduction in original length. 116 WEIGHT OF MATERIALS. Weight of Wrought-Iron Boltheads, Nuts, and Washers. Diameter of Bolt. Inches. Hexagon Heads and Nuts. Per Pair. Square Heads and Nuts. Per Pair. Round Washers. Per Pair. j. 20 to a lb. 16 to a lb. 20 to a lb. 4 A 10 to a lb. 8i to a lb. 10 to a lb. i 5 to a lb. to a lb. 5 to a lb. a A 2t to a lb. 2£ to a lb. 3 to a lb. 8 3 2 to a lb. 0.56 lb. 0.63 lb. 7 0.77 lb. 0.88 lb. 0.77 lb. 8 1 1.251b. 1.31 lb. 1.25 lb. 1! 1.75 lb. 2.10 lb. 1.751b. h 2.13 lb*. 2.56 lb. 2.25 lb. It 3.00 lb. 3.60 lb. 3.25 lb. 3.75 lb. 4.42 lb. 4.25 lb. J-2 It It H 2 4.75 lb. 5.70 lb. 5.25 lb. 5.75 lb. 7.00 lb. 6.50 lb. 7.27 lb. 8.72 lb. 8.00 lb. 8.75 lb. 10.50 lb. 9.60 lb. Weight of 100 Bolts With Square Heads and Nuts. (The Carnegie Steel Co Limited.) ! Diameter of Bolts. _L,engtu Under Head to Point. 1 E pi — ■ — fW o' - K & E f" Lb. Lb. 1" Lb. 11 4.0 7.0 10.5 15.2 22.5 39.5 63.0 1A 4.4 7.5 11.3 16.3 23.8 41.6 66.0 -Lf o 4.8 8.0 12.0 17.4 25.2 43.8 69.0 109.0 163 u 9A 5.2 8.5 12.8 18.5 26.5 45.8 72.0 113.3 169 91 o*5 9.0 13.5 19.6 27.8 48.0 75.0 117.5 174 93 5.8 9.5 14.3 20.7 29.1 50.1 78.0 121.8 180 *4 Q 6.3 10.0 15.0 21.8 30.5 52.3 81.0 126.0 185 O Qi 7.0 n.o 16.5 24.0 33.1 56.5 87.0 134.3 196 O3 A 7.8 12.0 18.0 26.2 35.8 60.8 93.1 142.5 207 8.5 13.0 19.5 28.4 38.4 65.0 99.1 151.0 218 a 9.3 14.0 21.0 30.6 41.1 69.3 105.2 159.6 229 0 10.0 15.0 22.5 32.8 43.7 73.5 111.3 168.0 240 o a A 10.8 16.0 24.0 35.0 46.4 77.8 117.3 176.6 251 u Ai 25.5 37.2 49.0 82.0 123.4 185.0 262 Da 7 27.0 39.4 51.7 86.3 129.4 193.7 273 1 71 28.5 41.6 54.3 90.5 135.0 202.0 284 * a Q 30.0 43.8 59.6 94.8 141.5 210.7 295 O Q 46.0 64.9 103.3 153.6 227.8 317 V in 48.2 70.2 111.8 165.7 224.8 339 1U 1 1 50.4 75.5 120.3 177.8 261.9 360 11 1 0 52.6 80.8 128.8 189.9 278.9 382 14 1 Q 86.1 137.3 202.0 296.0 404 lo 1 A . 91.4 145.8 214.1 313.0 426 14 1 K 96.7 154.3 226.2 330.1 448 lo 1 A 102.0 162.8 238.3 347.1 470 16 1 *1 107.3 171.0 250.4 364.2 492 17 1 0 112.6 179.5 262.6 381.2 514 18 1 n 117.9 188.0 274.7 398.3 536 iy 20 123.2 206.5 286.8 415.3 558 Per Inch 1.4 2.1 3.1 4.2 5.5 8.5 12.3 16.7 21.8 Addit’ al. — rrr-J RAILROAD IRON. 117 IRON REQUIRED FOR ONE MILE OF TRACK. Tons of Iron. Rule. — To find the number of tons of rails to the mile , divide the weight per yard by 7, and multiply by 11. Thus, for 56-pound rail, divide 56 by 7 equal 8 , multi- plied by 11 equal 88 tons, for 1 mile of single track. . Weight of Rail per Yard. Pounds. Tons per Mile. Weight of Rail per Yard. Pounds. Tons per Mile. Tons. Pounds. Tons. Pounds. 12 18 1,920 45 70 1,600 .14 22 48 75 960 16 25 320 50 78 1,280 18 28 640 52 81 1,600 20 31 960 56 88 22 34 1,280 57 89 1,280 25 39 640 60 94 640 26 40 1,920 62 97 960 27 42 960 64 100 1,280 28 44 65 102 * 320 30 47 320 68 106 1,920 33 51 1,920 70 110 35 55 72 113 320 40 62 1,920 76 119 960 Number of Rails, Splices, and Bolts per Mile of Track. Length of Rail. Feet. No. of Rails per Mile. No. of Splices. No. of Bolts, 4 to Each Joint. No. of Bolts, 6 to Each Joint. 18 586 1,168 2,336 3,504 20 528 1,056 2,112 3,168 21 503 1,006 2,012 3,018 22 480 960 1,920 2,880 24 440 880 1,760 2,640 25 422 844 1,688 2,532 26 406 812 1,624 2,436 27 391 782 1,564 2,346 28 377 754 1,508 2,262 30 352 704 1,408 2,112 Railroad Spikes per Mile of Track. Size Measured Under Head. Average No. per Keg of 200 Lb. Ties 2 Ft. Between Centers, 4 Spikes to a Tie. Rails Used. Pounds per Inches. Pounds. Kegs. Yard. X t 9 b 375 5,870 291 45 to 70 5 X & 400 5,170 26 40 to 56 5 X* 450 4,660 231 35 to 40 44X4 530 3,960 20 28 to 35 4 X4 600 3,520 17f 24 to 35 HWS XX 680 720 ' 3,110 2,910 154 14| 1 i 20 to 30 34 X ts 4X1 900 1,000 2,350 2,090 11 104 t 16 to 25 34 Xf 3 X§ 1,190 1,240 1,780 1,710 9 84 j- 16 to 20 24 X 1 1,342 1,575 74 12 to 16 118 WIRE ROPES . WIRE ROPES. Wire rot>es for mine use are made of either iron or steel, and are g e uer- allv round Flat wire ropes are sometimes used, but the round rope is the favorite for many reL>n^ and is generally . used in American practice, excentina in some of the deep metal mines having small compartment shafts. 6X Taner^ooes are sometimes used, the idea being to produce a rope of um- fv-.T'n-i Erpriffth that is to have it less strong and of less diameter at the cage fo T St £ e ?f is leTs^and greater in strength and diameter- at the djum^end? vd^re^he 8 lc^d^^is^^eatSt. The theory is correct . and some weight of rope is saved; but practically there is not much ^ is doubtful whether taper ropes will ever be generally used. The loug- established conviction that the best of all ropes for colliery use is a round one made of steel or iron has never been overcome and probably ne\er Wll Sfeei rones are in most respects superior to iron ropes, and are therefore crninimr in fa?or lvervTear. The principal advantage of a steel rope is that fr has ! greater stre iigt h th a n an iron rope of equal diameter; consequently it ^can be made lighter and can pass around pulleys and drums with less ^Mfenfng’ tof dmm therefs often a grievous error made. Men who will not Stink of passing a rope around a pulley of too small diameter will insert it in the drum rim in such a way as to make a very sharp curve, and make a weak point in the rope that would not other- wise exist. In the accompanying cut v a) shows the right and (6) the wrong way of passing the rope through the drum rim. The securing of the rope to the drum or --i the drum shaftly several Soils around around either the drum or the ; shaft ? a pull ^ ^Sn^^^^e^s^of^ur^lu^l^cases^auSe^margiif'be^veeu^th'Jb^^ loaded'fs unduly W wrnmmm i? 1 sns W th Tro P e' s houl,l not be changed from a large dn,m to sumebub mmmmmsrn «mn“cb^ e &idtoexmU wear for short distances at intervals WIRE ROPES. 119 along the rope. In the ordinary lay, Fig. (a), the wires are twisted in the opposite direction to the strands. This method prevents the rope from untwisting when in use, and the wires from unraveling when they are worn through or broken at the surface. In the Lang lay, Fig. (6), the wires are twisted in the same direction as the strands, thus giving each wire a greater wearing surface, while the rope is smoother and will wear longer A fter the wires begin to break, unraveling becomes troublesome, and it is more difficult to splice a Lang lay rope than an ordinary lay one. Hoisting ropes, especially those used to raise and lower men, should not be spliced The locked wire rope, a cross-section of which is shown in Fig. (c) consists of wires of special cross-section formed in concentric layers. The lav of the inner wires is opposite to that of the outer ones, and somewhat longer. This prevents untwisting, and brings the greater stress upon the outside layer, which is supposed to give way first. The inside layer, although inac- cessible, and therefore cannot be inspected or oiled, can be relied upon until the external portion of the rope wears out. This form of rope has a smooth cylindrical surface, but it is not so flexible as the other forms, and is most suitable for haulage purposes or bucket transportation. The life of a steel rope depends largely on the conditions to which it is subjected, and the care it receives. At some mines the ropes must be changed every six months, while at others the ropes last for one year and longer. Where the rope enters the socket by which it is attached to the cage is perhaps the place where signs of weakness will first appear. This point should be fre- quently inspected, and a new connection made every two or three months by cutting a few feet off the end and paying it out from the drum end. WEIGHTS AND STRENGTHS OF WIRE ROPES. Flat Ropes, ( Trenton Iron Co ., Trenton , N.J.) Size. Inches. Approximate Weight per Foot. Pounds. Breaking Stress. (Approximate.) Pounds. Iron. Cast Steel. 2 X| 1.35 20,000 40,000 2|X| 1.70 25,000 50,000 3X1 2.05 30,000 60,000 3| X I 2.40 35,000 70,000 4 XI 2.75 40,000 80,000 5 X | 3.45 50,000 100,000 6 X | 4.15 60,000 120,000 3X1 2.40 37,500 75,000 3|X | 2.S5 43,750 87,500 4 XI 3.30 50,000 100,000 5 X I 4.20 62,500 125,000 6 Xi 5.10 75,000 150,000 7 XI 6.00 87,500 175,000 8 XI 6.90 100,000 200,000 L safe working load allow from one-fifth to one-seventh of the break ing stress. 120 WIRE ROPES. •adoH ‘snox ‘qj^naijs ^ a Pl H9J £ t-COO^CC CS — — ~ •saqoni lajaniBia clctcW alts^^Vai i-la ' s^r » -: « - • ■ • - * — © i> ■SU°X _ Ny -r.o I*©-*? ©* mSnoiaS SuiqBOig; ! 0jBUIlXOlddy ; ; S -4 o 33 3 *0AB0qs io Ao3r<*«|MS5r«5 • unuQ jo 0 zis i 0 dojd — *-. | \_ ! •snox *p'BO r i Suiq-iOAl JOdoJd — ~ — xrjocc icxx x N x r — ~ — ac mi>cg ©«•* £ 3 - © © £ ^OX®U3 ccnn— <- i r-r:?lr--r- — ’“' •snox ^ I ^-'SSSSS'SSS •qjSnons Suppsaig 1 0jBinixojd(iy ; c<1 ’~ !t ^ t ~ i [ J •100J *0AB0HS JO i unua JO OZJS iooo J d I . ^ £ , 2£ 3£ g ^ ^i oc ©vo ^«^^.P! 0 . r, . r, l®. e5HX ' r - - - •snox wi t i SSS5522 353^ 33- • ■ SurqJoyL gadoid | gj 3 - - I •snox ■qjSuau'S ^aiqB 0 ia | 2©*© ojBinyxojddy i r- x £ -*•_ — ; £ |X*'lC Hi5' J t'K O'. C C 'T ?i S^ — — •spnnod •joox JB0HIX i0d jqSiOAY **• ^ ^ iX 1 'X* ^ ~ X - : ~i C'i — ■ — •soqoni ’00n0J0j -ninojio ojBaiixoiddy Scr?t^f?io»a5r ^ r««^ •saqoai ?T?Tcm 1— — — at » «*»«»-»♦ •adoH jo as a j 0 inao dni0H OJiAV-61 -puBiJS-xTS sadoH ^ui^sioh WIRE ROPES. 121 r- < rH rH rH rH ■4+ HOCftQOO rH rH HH-Ok-H« <0 10^^41 ok- Ha ok- o|* CO CO CM CM rH CM CO 00 CO o6 id cm © x rH r-i —h rH oq cm Tjj oo cd H rj? cd cm* OHNr-CO CM l> CM X CM* rH* rH rHOO^^OCM 05 I> CO lO Tt< 04 T* rH 4> T* CO 04 CM H r-> iC lO IO IO io CO X CO rH X CO cd r oo i'- i> co io H« ok- Ha ■^'tWCOCO 00 CO CM CM id CO rH 05 |> HHH O O X CM CO CO CM CO O ^ id H cd cd oi 1.94 1 1.50 1.11 .77 .64 05XCOCOt~* i> CO iO ^ X rH CO X rH 00 id CM* CM CM rH rH rH O O X X CM I>OiOXC4 05 1 > id cd cd -*l=* 00 I> !>• 50 io Ha ok- Ha THrf CO* id X* CM n* rH 1 3.55 3.00 2.45 2.00 1.58 O 051004 O CM X CO iO i rH * * ' ' j lO 05 O CM lO CM X X CM rH H ok-H* H« , CO X 1 ok-H-+-l<» ok- . CM CM CM CM rH , HaHHr|® r|os HrHHrl ■Ha -HraH+Ha) i 1—1 rH rH rH rH •jaitiao draan ‘ajtA\-uaAag ‘puBj}g-xig ‘sadoy; uoissiuisubjj, puB aihqnBfj The wire-rope table given on pages 120 and 121 is a rearrangement of the standard tables published in the cata- logues of most of the American manu- facturers of wire rope. The proper working load given in this table is one-fifth of the ap- proximate breaking stress, that is, a factor of safety of 5 is used, and when the values given in this table are used this factor is supposed to allow for the bending stress. The sizes of sheaves or drums given in this fable are largely empirical, but they are based on a long experience in the use of wire ropes, and in most cases represent the minimum diam- eter recommended by the rope makers. The factor of safety of 5 assumes ordi- nary conditions of working; where the conditions are extraordinary, and particularly in cases where men are to be hoisted, a larger factor than 5 is used, varying from 5 to 10. Many ele- vator specifications require a factor of 10 to be used. When any factor but 5 is used, the proper working load is obtained by dividing the approxi- mate breaking stress by the factor of safety assumed, or, if we know the load to be lifted and multiplv this by the assumed factor, we obtain a certain value, and by comparing this with the values given in the table for the approximate breaking stress we can determine the size of rope, and the minimum diameter of sheave to use. For example, suppose it is desired to determine the size of rope needed to hoist a load of 8 tons through a height of 300 feet. Multiplying 8 by 5, we have 40 tons, and from the table we find that the approximate breaking strength of a lf-inch, crucible-steel hoisting rope is 42 tons. Such a rope weighs 2 pounds per foot; hence, the weight of the rope is 300 X 2 = 600 pounds, or .3 of a ton, and the total load on the rope is therefore 8.3 tons. 8.3 X 5 = 41.5, which is less than the approximate breaking stress for the given rope. The proper size of sheave or drum for this rope is given by the table as 4| feet. Galvanized wire is sometimes used in the manufacture of rope to prevent corrosion of the iron or steel of the wire. Galvanizing accomplishes this in the case of standing ropes but is not effective for running ropes, in which the friction of the rope against sheaves or drums soon wears off a por- tion of the zinc, and with both zinc and iron exposed and in contact with water, corrosion proceeds more rapidly than it would if the zinc were not present. 122 WIRE ROPES. flattened-strand rope. Fig r x Fig. 2. FlG - 3 * able saving in the wear of pulleys and sheaves. Patent Flattened-Strand Rope. ( From, A. Leschen & Sons Rope Co., St. Louis , Mo.) © ft o P3 be © © ft © u eg a © •rH O © 4-=> c$ a o s-t ft ft ft 24 2 If If H If li H l 7 8 * •4 7.06 6.28 5.49 5.10 4.71 4.32 3.92 3.53 3.14 2.74 2.35 1.96 1.57 Swedish Iron, ■; l 14 14 l 8.50 6.50 5.00 4.33 3.71 3.17 2.50 2.15 1.70 1.25 .96 .67 .44 bc£ ft o ft II © © S-l ft o © c c ~d © a H ‘S . a. a ft 3 ft f - 1 “§ 3°. |o ^ 02 © S3 d r > c ft ^ 5 02 75 66 54 45 40 34 28 21 17 13 9 6 4 a 2 ft © . N © 35 a^ ft o Crucible Cast Steel. 15.0 13.2 10.8 9.0 8.0 6.8 5.6 4.2 3.4 2.6 1.8 1.2 .8 3.92 2.40 27.0 5.4 104 54. 3.53 2.00 22.5 4.5 94 45. 3.14 1.64 18.0 3.6 84 36. 2.75 1.20 13.5 2.7 74 27. 2.35 .93 10.0 2.0 64 20. 1.96 .68 7.0 1.4 54 14. 1.57 .40 4.5 .9 4 9. 1.17 .25 1 5. 10 & 74 7 64 6 5 44 4 34 3 24 If bc^ 38 d©. © f tramway is capable of carrying individual loads up to 1,400 or 1,500 pounds, not including the weights of the bucket and hanger itself. The speed of traction rope may be from 150 to 350 feet per minute. The capacity is from 200 to 1,000 tons per day of 10 hours. These figures represent good, safe practice, but they are not, of course, inflexible. The maximum length of line which may be built in one section varies largely with conditions of load, spacing of supports, contour of ground, etc. Wire-rope tramwavs work under great difficulties, and probablv 2* to 4 miles is the economical iimit. This has been exceeded, but the trouble is that for a much greater distance the friction becomes too great for economical work- ing of the traction rope. This does not, however, limit the length of tram- wav which may be built, as the power station may be located at a convenient intermediate point, dividing the line into sections. Several intermediate power stations may be used, and the length of the line greatly increased above the limit given. A tramway at Grand Encampment, Wyoming, is 16 miles long and carries 40 tons of ore per hour. TRANSMISSION OF POWER BY WIRE ROPES. The term transmission, as here used, applies simply to the modification of belt driving, using grooved wheels or sheaves at each end of the line, lhe power is applied to one sheave and taken off from the other . The friction between rope and sheaves depends directly on the weight and tension of the rope and on the nature of the surfaces in contact. This pressure is better obtained by using a large, heavy rope at a low tension than by using a smaller rope at a high tension. . ^ - The deflection or sag of the rope, between the sheaves, is the same for both upper and lower parts of the rope when the transmission is not running and should be, according to John A. Roebling’s Sons Co., equal to about one- thirty-sixth of the span. The deflection may be calculated by the formula from the Trenton Iron Co.: . w s 2 h _ 8 1 * in which h = the deflection in feet; w = weight of the rope per foot, in pounds; 8 — span, in feet; t = tension, in pounds. When driving from the under side, this part of the rope will be tightened and its deflection decreased, while the upper part of the rope becomes slack- ened and its deflection increased. Under proper conditions the deflection ot the lower rope should be about one-fiftieth, and that of the upper about one- twenty- fifth of the span. The difference in the tensions of the two parts of the rope is the effective pull of the driving sheaves, enabling power to be transmitted. Transmission ropes are subject to three stresses, viz.: .. * (1) The direct tension, due to the power transmitted, plus the friction ana weight of the rope; (2) the bending stress, due to the bending of the rope around the sheaves; (3) the centrifugal tension, due to the centrifugal force in the rapidly running rope. . . •, _ Mr wm The following data on stresses m transmission ropes are given by Mr. V\ m. Hewitt, of the Trenton Iron Co. . . . , In transmitting power by wire rope, working tension should not exceed WIRE ROPES. 122e 1 the difference between the maximum safe stress and the bending stress. It may be greater, therefore, as the bending stress is less, but to avoid slipping a certain ratio must exist between the tensions in taut and slack portions of the rope when running, which is determined by the formula T= Sefm; in which T = tension in the taut portion of the rope; S = tension in the slack portion; e = base of the Naperian system of logarithms — 2.7182818; n = number of half laps of rope about sheaves or drums at either end of line; 7r = 3.1416; f = coefficient of friction depending on the kind of filling in the grooves of the sheaves, or character of the material on which the rope tracks. The useful effort of transmitting force is the difference between the tension of the taut and slack portions of the rope. T — S = & (ef n ^ — 1), and to obtain this, the initial tension, or tension when the rope is at rest, must be one-half the sum of the two tensions. e fn 7T _L 1 TP S = + i) = __ r ^_ (T-S). The following are some of the values of / : Dry rope on a grooved iron drum 120 Wet 'rope on a grooved iron drum 085 Greasy rope on a grooved iron drum 070 Dry rope on wood-filled sheaves 235 Wet rope on wood-filled sheaves .170 Greasy rope on wood-filled sheaves 140 Dry rope on rubber and leather filling 495 Wet rope on rubber and leather filling 400 Greasy rope on rubber and leather filling 205 e f n TT -. — i above values of/, for one up to six half laps of the rope, are as follows: Values of efm *. f = n = Number of Half Laps About Sheaves or Drums at Either End of Line. 1 2 3 4 5 6 .070 1.246 1.552 1.934 2.410 3.003 3.741 .085 1.306 1.706 2.228 2.910 3.801 4.964 .100 1.369 1.875 2.566 3.514 4.810 6.586 .120 1.458 2.125 3.099 4.518 6.586 9.602 .130 1.504 2.263 3.405 5.122 7.706 11.593 .140 1.552 2.410 3.741 5.808 9.017 13.998 .150 1.602 2.566 4.111 6.586 10.551 16.902 .170 1.706 2.910 4.964 8.467 14.445 24.641 .200 1.875 3.514 6.586 12.346 23.140 43.376 .205 1.904 3.626 6.904 13.146 25.031 47.663 .235 2.092 4.378 9.160 19.166 40.100 * 83.902 .250 2.193 4.810 10.551 23.140 50.637 111.318 .265 2.299 5.286 12.153 27.941 64.239 147 693 .300 2.566 6.586 16.902 43.376 111.318 285.680 .350 3.001 9.017 27.077 81.307 244.152 733.145 .400 3.514 12.346 43.376 * 152.405 535.488 1,849.140 .410 3.626 13.146 47.663 172.814 626.577 2,271.775 .450 4.111 16.902 69.487 285.680 1,174.480 4,828.510 .495 4.716 22.425 106.194 502.881 2,381.400 .500 4.810 23.140 111.318 535.488 2,575.940 A 122f WIRE ROPES. Values of ef n 7T + l e t n 7T _ 1* / = n = Number of Half Laps About Sheaves or Drums at Either End of Line. 1 2 3 4 5 6 .070 9.130 4.623 3.141 2.418 1.999 1.729 .085 7.536 3.833 2.629 2.047 1.714 1.505 .100 6.420 3.287 2.280 1.795 1.525 1.358 .120 5.345 2.777 1.953 1.570 1.358 1.232 .130 4.968 2.584 1.832 1.485 1.298 1.189 .140 4.623 2.418 1.729 1.416 1.249 1.154 .150 4.322 2.280 1.643 1.358 1.209 1.126 .170 3.833 2.047 1.505 1.268 1.149 1.085 .200 3.287 1.795 1.358 1.176 1.090 1.047 .205 3.212 1.762 1.338 1.165 1.083 1.043 .235 2.831 1.592 1.245 1.110 1.051 1.024 .250 2.676 1.525 1.209 1.090 1.010 1.018 .265 2.539 • 1.467 1.179 1.072 1.032 1.014 .300 2.280 1.358 1.126 1.047 1.018 1.007 .350 2.000 1.249 1.077 1.025 1.008 1.003 .400 1.795 1.176 1.047 1.013 1.004 1.001 .410 1.765 1.164 L043 1.012 1.003 1.001 .450 1.643 1.126 1.029 1.007 1.002 1.000 .495 1.538 1.093 3 .019 1.004 1.001 1.000 .500 1.525 1.090 1.018 1.004 1.001 1.000 For a given diameter of sheave, and a variable diameter of wire, a ratio exists between these diameters corresponding to a maximum working tension. This ratio results, approximately, in a working tension of one- third and bending stress of two-thirds of the maximum safe tension, which is from one-third to two-fifths of the ultimate stress, and practically deter- mines the minimum diameter of sheave for any rope. The ratio for any size of wire varies slightly, according to the number of wires composing the rope, and in terms of rope diameter is, For 7-wire rope For 12-wire rope - For 19-wire rope * from which we derive the following table: Diam- eter of Rope. T5 i Steel. T5 5 ft 7- Wire. 20 25 30 35 40 45 50 55 60 70 80 12- Wire. 15 19 22 26 30 33 37 41 44 52 59 19- Wire. 12 15 18 21 24 27 30 32 35 41 47 40 50 60 70 80 90 100 110 120 140 160 Steel Iron 79.6 160.5 59.3 120.0 47.2 95.8 IN INCHES. Iron. 12-Wire. 19-Wire. 30 24 38 30 45 36 53 42 60 48 68 54 75 60 83 66 90 72 105 84 120 96 WIRE ROPES. 122g Sheaves. — To decrease the bending stresses the sheaves for wire-rope transmissions are generally of as large diameter as is practicable to give the required speed to the rope. Large sheaves are also advantageous because with them the rope is run at a high velocity allowing of a lower tension, and permitting a rope of smaller diameter to be used than would be pos- sible with smaller sheaves, provided, of course, that the span is of suffi- cient length to give the necessary weight. Sheaves are generally made of cast iron when not exceeding 12 feet in diameter, and when larger than this they are usually built up with wrought- iron arms. Sheaves, upon which the rope is to make but a single half-turn, are made with V-shaped grooves in their circumference. The bottom part of the groove is widened to receive the tilling, which consists of some sub- stance to give a bed for the rope to run on and protect it from wear, and to increase the friction so that the rope will not slip. This filling is made of blocks of wood, rubber, and leather, or other material. Rubber and leather have been used separately, but blocks of rubber separated by pieces of leather have been found to give the best results. Power Transmitted. — The horsepower transmitted is equal to the resistance overcome (the effective null), in pounds, multiplied by the speed of the rope, in feet per minute, and divided by 33,000, that is (formula from John A. Roebling’s Sons Co.), T V H= w,m' in which H = horsepower transmitted; T = difference in tension between the driving and driven sides of the rope; V = speed of the rope, in feet per minute. In applying this formula, V is either given or assumed. T is equal to the weight of the rope suspended between the sheaves multiplied by three (for the proportion of deflection stated). To transmit a given horsepower, the speed of the rope may be increased and the tension (effective pull) correspondingly decreased, and a smaller rope may be used provided other considerations will allow it. For determining the horsepower that can be transmitted over a given transmission, the following formula is given by the Trenton Iron Co.: H=[cd 2 - .000006 ( W + g' + g")] s ; in which H — horsepower that can be transmitted; c = constant depending on material of rope, the filling in the grooves of the sheaves, and the number of half laps about the sheaves or drums at either end of the line; d = diameter of rope, in inches; W — weight of rope, in pounds; ' g f = weight of terminal sheaves and shafts; g" = weight of intermediate sheaves and shafts. The following table gives the value of c for ropes on different materials: VALUE OF C FOR ROPES ON DIFFERENT MATERIALS. c — for Steel Rope on Number of Half Laps About Sheaves or Drums at Either End of Line. 1 2 3 4 5 6 Iron 5.6L 8.81 10.62 11.65 12.16 12.56 Wood 6.70 9.93 11.51 12.26 12.66 12.83 Rubber and Leather 9.29 11.95 12.70 12.91 12.97 13.00 The values of c for iron rope are one-half of the above. It is evident from the above figures that when more than three laps are made it is immaterial what the surface is on which the rope tracks, as far as frictional adhesion is concerned. 122h WIRE ROPES. From the foregoing formula, assuming the sheaves to be of equal diameter, and of a size not less than the minimum diameter given in the table, we deduce the following: HORSEPOWER CAPABLE OF BEING TRANSMITTED BY A STEEL ROPE MAKING A SINGLE LAP ON WOOD-FILLED SHEAVES Diam- eter of Rope in Inches. Velocity of Rope in Feet per Second. T6 i T6 f ii 10 20 30 40 50 60 70 80 90 100 4 8 13 17 21 25 28 32 37 40 7 13 20 26 33 40 44 51 57 62 10 19 28 38 47 56 64 73 80 89 13 26 38 51 63 75 88 99 109 121 17 34 51 67 83 99 115 130 144 159 22 43 65 86 106 128 147 167 184 203 27 53 79 104 130 155 179 203 225 247 32 63 95 126 157 186 217 245 38 76 103 150 186 223 52 104 156 206 68 135 | 202 The horsepower that may be transmitted by iron ropes is one-half of the The foregoing table gives the maximum amount of power capable of being transmitted under the conditions stated, so that in using wood-lined sheaves, it is well to make some allowance for the stretching of the rope, and to advocate somewhat heavier equipments than the above table would give- that is, if it is desired to transmit 20 horsepower, for instance, to put m a plant that would transmit 25 to 30 horsepower, thus avoiding the necessity of having to take up a comparatively small amount of stretch. On rubber and leather filling however, the amount of power capable of being transmitted is considerablv greater than on wood, so that this filling is generally used; and in this case no allowance need be made for stretch as such sheaves^ will likely transmit the power given by the table, under all possible deflections of the rope. Thet sheaves, rope makes but a single lap, or a half lap at either end of the line. GLOSSARY OF ROPE TERMS. Anneaf°d Wire Rope.— A wire rope made from wires that have been softened bvannealing and the tensile strength thereby lowered. Bending Stress.— 1 The stress produced in the outer fibers of a rope by bending over a sheave or drum. , +v . Breaking Strain Breaking Strength , Breaking Stress.—' The least load that will break a rope. These terms are used indiscriminately to mean the load which will break a rope. The stress on a rope at tne moment of breaking is the breaking stress , and the strain or deformation produced in the material bv this stress is the breaking strain. Bright Rope.— Rope of any construction, whose wires have not been gal- vanized, tinned, or otherwise coated. , . o Cable-Laid Rope— A term applied to wire cables made of several ropes twisted together, each rope being composed of strands twisted together without limitation as to the number of strands or direction of twist A fiber cable-laid rope is a rope having three strands of hawser-laid rope, twisted right-handed. WIRE ROPES. 122i Cable —Same as cable-laid rope ; a fiber cable consists of three hawsers laid up left-handed. . . _ , Cast Steel— Steel that has been melted, cast into ingots, and rolled out into bars. . , * . . Clamp— A device for holding two pieces or parts of rope together by pressure. , „ Clip — a device similar to a clamp but smaller and for the same purpose. Coir. — Coconut-husk fiber. Compound.— A lubricant applied to the inside and outside of ropes pre- venting corrosion and lessening abrasion of the rope when in contact with hard surfaces. Core— The central part of a rope forming a cushion for the strands. In wire ropes it is sometimes made of wire, but usually it is of hemp, jute, or some like material. Coupling. — A device for joining two rope ends without splicing. Crucible Steel.— A fine quality of steel made by the crucible process. Drum. — The part of a hoisting engine on which the rope is wound. Elastic Limit.— The elastic limit is-that point at which the deformations in the material cease to be proportional to the stresses. Elevator Rope.— A rope used to operate an elevator. Endless Rope— A rope which moves in one direction, one part of which carries loaded cars from a mine at the same time that another part brings the empties into the mine. Fiber— A single thread-like filament. Flat Rope.— A rope in which the strands are woven or sewed together to form a flat, braid-like rope. Flattened-Strand Rope.— A wire rope whose strands are flattened or oval and which therefore presents an increased wearing surface over that of the ordinary round-strand rope. Flattened-Strand Triangular Rope— A wire rope of the flattened-strand con- struction in which the strands are triangular in shape. Fl ee t— Movement of a rope sideways in winding on a drum. Fleet Wheel.— A grooved wheel or sheave that serves as a drum and about which one or more coils of a haulage rope pass. Galvanized Rope.— Rope made of wires that have been galvanized or coated with zinc to protect them from corrosion. Grip Wheel.— A wheel, the periphery of which is fitted with a series of toggle-jointed, cast-steel jaws that grip the rope automatically. Guy.— A strand or rope used to support a pole, structure, derrick, or chim- ney, etc. Haulage Rope.— A rope used for haulage purposes. Hawser.— A term applied to any wire rope used for towing on lake or sea. A fiber hawser consists of three strands laid up right-handed. Hawser- Laid Rope has three strands of yarn twisted left-handed, the yarns being laid up right-handed. Synonymous with cable-laid rope as applied to wire ropes. Hawser Wire Rope.— Galvanized ropes of iron or steel usually composed of six strands, 12 wires each, principally used in marine work for towing purposes. Hemp.— A tough, strong fiber obtained from the hemp plant. Hoisting Rone— A rope composed of a sufficient number of wires and strands to insure flexibility. Such ropes are used in shafts, elevators, quarries, etc. Idler.— A sheave or pulley running loose on a shaft to guide or support Jute.— A fiber obtained from the inner bark of two Asiatic herbs: Corchorus capsularis and C. olitorius. Lang-Lay Rope.— A rope in which the wires in each strand are twisted in the same direction as the strands in the rope. Lay— A term indicating the direction, or length, of twist of the wires and strands in a rope. Live Load.— A load which is variable in distinction from a constant load. Load Stress. — The stress produced by the load. Locked- Wire Rope— A rope with a smooth cylindrical surface, the outer wires of which are drawn to such shape that each one interlocks with the other and the wires are disposed in concentric layers about a wire core instead pf in strands. Particularly adapted for haulage and rope- transmission purposes. 122j WIRE ROPES. Manila.— The fiber of Musa textilis; Manila hemp. „ _ Modulus of Elasticity. — The ratio between the amount of extension or com- pression of a material and the load producing this same extension or compression. , . Plow Steel.— & select grade of steel of high tensile strength. First used in rope for plowing fields. , . . , , ... , Proper Working Load.— The maximum load that a rope should be permitted to support under working conditions. (See working load.) Regular-Lay Rope— A. rope in which the wires in each strand are twisted in ODposite direction to the strands in the rope. Round-Strand Rope.— A rope made of round twisted strands. Running Rope.— A flexible rope that will pass througn blocks and used for hoisting on shipboard. The term is also often used for any moving rope. Sheave.— A wheel or pulley around or over which a rope passes. Shroud Laid , or Four-Strand , Rope has four strands laid around a core. Sisal— A hemp. The fiber of the Agave Sisalona. . Socket.— A device fastened to the; end of a rope by means of which the rope mav be attached to its load. The socket may be opened or closed. Splice —The joining of two ends of rope by interweaving the strands. Step Socket.— A special form of socket for use on locked-wire rope. Stirrup— An adjustable bale of a socket _ . Stone Wire.— A term applied to wire smaller than No. 14 put up m 12-pound coils, which are about 8 inches inside' diameter. Strand— A term applied to a varying number of wires or fibers twisted together. The strands in turn are twisted together, forming a rope. Stress. -A force or combination of forces tending to change the shape of a Strain.— A chahge of shape produced in a body. (Stress and strain are often used incorrectly as synonymous terms.) Surging.— The flapping of a moving rope. Swedish Iron.— A soft and comparatively pure iron. Switch Rope.— A short length of rope fitted with a hook on one end and a link on the other, used for the switching of freight cars. Tail-Rope— (1) The rope that is used to draw the empties back into a mine in a tail-rope haulage system. (2) A rope attached beneath the cage when the cages are hoisting in balance. Taper Rope. — A rope which has a gradually diminishing diameter frorn the upper to the lower end. The diameter of the rope is decreased by 1 dropping one wire at a time at regular intervals. Both round and flat ropes may be made tapered, and such ropes are intended for deep-shaft hoisting with a view to proportioning the diameter of the rope to the load to be sustained at different depths. Tensile Strength— The stress required to break a rope by pulling it in two. Thimble. — An oval iron ring around which a rope end is bent and fastened to form an eye. ■ ,, „ Tiller Rope.— A very flexible wire rope composed of six small ropes, usually of seven-wire strands laid about a hemp core. . Tinned Rope.— Rope made of wires that have been coated with tin to protect them from corrosion . , Torsion. — The process of twisting a wire thereby showing its ductility. Traction Rope— A rope used for transmitting the power in a wire-rope tram- way and to which the buckets are attached. Transmission Rope. — A rope used for transmitting power. Traveler.— A truck rolling along a suspended rope for supporting a load to be transported. „ „ . , ^ Turnbuckle— A form of coupling so threaded or swiveled that by turning it the tension of a rope or rod may be regulated. Ultimate Tensile Strength.— Same as tensile strength. Universal Lay— Another term for lang lay. Whipping.— The flopping of a moving rope. Wire Gauge.— Standard sizes or diameters for wire. Wire Rope— A rope whose strands are made of wires, twisted or woven together Working Load.- The maximum load that a rope can carry under the con- ditions of working without danger of straining. (Same as proper work- ingload.) . Wrought Iron — A comparatively pure and malleable iron. , Yarn.— 1 Twisted fiber of which rope strands are made. Ife. 00 00 00 00 00 00 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 r IRE AND SHEET-METAL GAUGES. OF WIRE AND SHEET-METAL GAUGES. British Wire Gauge. (Legal Standard n Great Britain.) Millim. 127 11.78 10.97 10.16 9.45 8.84 8.23 7.62 7.01 6.4 5.89 5.38 4.88 4.47 4.06 3.66 3.26 2.95 2.64 2.34 2.03 1.83 1.63 1.42 1.22 1.01 .91 .81 .71 .61 .56 .51 .45 .42 .38 .35 .31 .29 .27 .25 .23 .21 .19 .17 .15 .13 .12 .11 .10 .09 .08 .07 .06 .05 04 .03 .025 Birming- ham Gauge. Inch. American or Brown . and Sharpe Gauge, inch. Roebling's Gauge. Inch. Trenton Iron Co.’s ‘Wire ! Gauge. Inch. English Legal Standard. Inch. .49 .46 .500 ( .464 .43 .45 .432 .454 .46 .393 .40 .4 .425 .40964 .362 .36 .372 .38 .3648 .331 .33 .348 .34 .32486 .307 .305 .324 .3 .2893 .283 .285 .3 .284 .25763 .263 .265 .276 .259 .22942 .244 .245 .252 .238 .20431 .225 .225 .232 .22 .18194 .207 .205 .212 .203 .16202 .192 .19 .192 .18 .14428 .177 .175 .176 .165 .12849 .162 .16 .16 .148 .11443 .148 .145 .144 .134 .10189 .135 .13 .128 .12 .09074 .12 .1175 .116 .109 .08081 .105 .105 .104 .095 .07196 .092 .0925 .092 .083 .06408 .08 .08 .08 .072 .05707 .072 .07 .072 .065 .05082 .063 .061 .064 .058 .04526 .054 .0525 .056 .049 .0403 .047 .045 .048, .042 .03589 .041 .04 .04 .035 .03196 .035 .035 .036 .032 .02846 .032 .031 .032 .028 .02535 .028 .028 .028 .025 .02257 .025 .025 .024 .022 .0201 .023 .0225 .022 .02 .0179 .02 .02 .02 .018 .01594 .018 .018 .018 .016 .01419 .017 .017 .0164 .014 .01264 .016 .016 .0148 .013 .01126 .015 .015 .0136 .012 .01002 .014 .014 .0124 .01 .00893 .0135 .013 .0116 .009 .00795 .013 .012 .0108 .008 .00708 .011 .011 .01 .007 .0063 .01 .01 .0092 .005 .00561 .0095 .0095 .0084 .004 .005 .009 .009 .0076 .00445 .0085 .0085 .0068 .00396 .008 .008 .006 .00353 .0075 .0075 .0052 .00314 .007 .007 f .0048 .0044 .004 .0036 .0032 . .0028 .0024 .002 .0016 .0012 .001 1221 WIRE ROPES. STRESS IN HOISTING ROPES ON INCLINED PLANES OF VARIOUS DEGREES. (From “Wire-Rope Transportation “ published by Trenton Iron Co.) The following table is based upon an allowance of 40 lb. per ton for rolling friction, but there will be an additional stress due to the weight of the rope and inclination of the plane. Rise per 100 Ft. Horizontal. Ft. Angle of Inclination. Stress in Lb. per Ton of 2.000 Lb. 5 9° 52' 140 10 5° 43' 240 15 8° 32' 1 336 20 11° lO' 432 25 14° 03' 527 30 16° 42' 613 35 19° 18' 700 40 21° 49' 782 45 24° 14' 860 50 26° 34' 933 55 28° 49' 1.003 60 30° 58' 1,067 65 33° 02' 1,128 • 70 35° 00' 1.185 75 36° 53' 1,238 80 38° 40' 1.287 85 40° 22' 1.332 90 42° 00' 1.375 95 43° 32' 1.415 100 45° 00' 1.450 Rise per 100 Ft. Horizontal. Ft. Angle of Inclination. i Stress in Lb. per Ton of 2, 000 Lb. 105 46° 24' | 1,484 110 47° 44' 1.516 115 49° 00' 1,535 120 50° L* 1,573 125 51° 21' 1.597 130 52° 26' 1.620 135 53° 29' 1,642 140 54° 28' 1.663 145 55° 25' 1.682 150 56° 19 7 1.699 155 57° 11' 1.715 160 58° 00' 1 1.730 165 58° 47' 1.744 170 j 59° 33' 1,758 175 60° 16' 1,771 180 60° 57' 1.782 185 61° 37' 1.794 190 ! 62° 15' 1,804 195 62° 52' 1.813 200 63° 27' ; 1.822 RELATIVE EFFECTS OF VARIOUS SIZED SHEAVES OR DRUMS ON THE LIFE OF WIRE ROPES. Aline officials and other users of wire ropes have often felt the want of a table or set of tables that would enable them to determine at a glance what effect the use of various sized sheaves would have on various sized ropes. The following tables have been specially prepared for the Coal and Metal Aimer's Poeketbook bv Air. Thomas E. Hughes, of Pittsburg, Pa. cast-steel ropes for inclines. Made of 6 Strands of 7 Wires Each, Laid Around a Hemp Core. Diameters of Sheaves or Drums in Feet, Showing Percentages Diameter 0 f Life for Various Diameters. of _ = Rope. Inches. 100? j 90* * 80£ 75£ | 601 501 25* 11 16.00 14.00 12.00 11.00 9.00 7.00 4.75 a 8 li 14.00 12.00 10.00 8.50 7-00 6.00 1 £2 •*■8 11 12.00 10.00 8.00 7.25 6.00 1 5.50 \ 4.2 d I4 11 10.00 8.50 7.75 7.00 6-00 ! ! 5.00 ; 4.00 a 8 1 8.50 7.75 6.75 6.00 5.00 4.50 3.75 J. * 7.75 7.00 6.25 5.75 4.50 3. /D 3.25 8 3 7.00 6.25 5.50 5.00 I 4.25 3.50 2.75 * 6.Q0 5.25 4.50 4.00 3-25 i 3.00 2.50 8 £ 5.00 4.50 4.00 3.50 2.75 j 2.25 ; 1.75 X OTE _\y e do not publish a table of iron ropes for inclines as the use of iron ropes for this purpose has been generally abandoned, steel ropes being far more satisfactory and economical. WIRE ROPES. m CAST-STEEL HOISTING ROPES. Made of 6 Strands of 19 Wires Each, Laid Around a Hemp Core. _ . , Diameters of Sheaves or Drums in Feet, Showing Percentages Diameter 0 f Li f e for Various Diameters. of Hope. Inches. 100/* 90/ 80/ 75/ 60/ 50/ 25/ H 14.00 12.00 • 10.00 8.50 7.00 6.00 4.50 If 12.00 10.00 8.00 7.00 6.00 5.25 4.25 If 10.00 8.50 7.50 6.75 5.50 5.00 4.00 If 9.00 7.50 6.50 5.50 5.00 4.50 3.75 1 8.00 7.00 6.00 5.50 4.50 4.00 3.50 2 . 7.50 6.75 5.75 5.00 4.25 3.50 3.00 1 f 2 3.' 8 5.50 4.50 4.00 3.75 3.25 3.00 2.25 4.50 4.00 3.75 3.25 3.00 2.50 2.00 4.00 3.00 3.00 3.00 2.75 2.00 2.25 2.00 1.50 1.50 IRON HOISTING ROPES. Made of 6 Strands of 19 Wires Each, Laid Around a Hemp Core. . Diameters of Sheaves or Drums in Feet, Showing Percentages Diameter of Life for y ar i 0 us Diameters. of Rope. Inches. 100/ 90/ 80/ 75/ 60/ 50/ 25/ If- 12.00 11.00 9.00 7.50 6.00 5.00 3.00 If 10.00 9.00 7.50 7.00 5.25 4.75 4.00 If 9.00 7.75 6.50 5.75 4.50 4.00 3.50 If 8.00 6.75 5.50 5.00 4.25 3.50 3.00 1 6.75 6.00 5.00 4.75 4.00 3.25 2.75 z 6.75 6.00 5.00 4.50 4.00 3.00 2.50 6 f 5.00 4.75 4.00 3.75 3.00 2.75 2.00 f 4.50 3.75 3.25 3.00 2.75 2.25 1.75 3.50 3.25 3.00 2.75 2.00 1.50 1.00 I 3.00 2.00 1.25 1.00 Wire rope is as pliable as new hemp rope of the same strength; the former will therefore run on the same sized sheaves and pulleys as the latter. But the greater the diameter of the sheaves, pulleys, and drums, the longer wire rope will last. In the construction of machinery for wire rope, it will be found good economy to make the drums and sheaves as large as possible. The tables of wire-rope manufacturers give “ proper diameters of drum or sheave” at from 50 to 65 times the rope diameter; but the expression would more properly be the “minimum admissible diameter.” For ordinary ser- vice, by using sheaves and drums from 75 to 100 times the diameter of the rope, the average life of hoisting ropes would be materially lengthened. For rapid hoisting, during which abnormal strains are most likely to occur, or where a low factor of safety is employed, a sheave diameter of 150 times that of the rope is to be recommended. Experience has demonstrated that the wear increases with the speed. It is therefore better to increase the load than the speed. Wire rope is manu- factured either with a wire or a hemp center. The latter is more pliable than the former, and will wear better where there is short bending. Wire rope must not be coiled or uncoiled like hemp rope. When mounted on a reel, the latter should be mounted on a spindle or flat turntable to pay off the rope. When forwarded in a small coil, without reel, roll it over the ground like a wheel, and run off the rope in that way. All untwisting or kinking must be avoided. 124 WIRE ROPES. EXTRA STRAIN ON A HOISTING ROPE WITH A FEW INCHES OF SLACK CHAIN Dynamometer Tests. First Test Empty cage lifted gently : Empty cage with 2\ inches slack chain Empty cage with 6 inches slack chain : Empty cage with 12 inches slack chain Second Test Cage and four empty cars weighed by machine Cage and four empty cars lifted gently ..................... Cage and four empty cars with 3 inches slack chain Cage and four empty cars with 6 inches slack chain Cage and four empty cars with 12 inches slack chain Third Test Cage and full cars weighed by machine No. 1, lifted gently No. 2, lifted gently No. 1, with 3 inches slack chain No. 2, with 3 inches slack chain No. 1, with 6 inches slack chain No. 2, with 6 inches slack chain No. 1, with 9 inches slack chain - No. 2, with 9 inches slack chain Tons. Cwts. 1 16 2 10 4 0 5 10 2 17 3 0 5 0 5 10 7 0 5 1 5 1 5 3 8 10 8 10 10 10 11 10 12 10 11 10 WIRE-ROPE CALCULATIONS. The working load, also called the proper working load, is the maximum ioad that a rope should be permitted to support under working conditions. The stress on a rope to which a load is attached, and which bends over a sheave, is made up of two parts: (1) That due to the load on the rope, known as the load stress; (2) that due to the bending of the rope about a sheave or drum, known as the bending stress. That is, if S = total safe stress; S b = bending stress; Si = load stress; S = S b + S, and Si = S — S b . The total stress must not equal the elastic limit of the material composing the rope and is usually taken as from one-third to one-fourth the approxi- ma it is only quite recently that account has been taken of this second stress in wire-rope problems, and it is riot, as yet, by any means universal practice to consider it in calculating the size of rope needed for a given purpose. If we have a given weight to hoist with a wire rope, the to use may be taken directly from the tables on pages 120, 121, 122, but this does not take account of the bending stress, except by allowing for it in the factor of safety assumed. t A second method calculates the bending stress. The following formulas and the diagram based on them, given on page 125, are given bv Mr. E. T. Sederholm, former chief engineer for Fraser & Chalmers, and will be found in the hoisting-engine catalogue of the Allis-Chalmers Co. The general formula for the bending stress is _EaA, bb D > in which S h = bending stress; E = modulus of elasticity; a = diameter of each wire; D = diameter of drum or sheave; . . A = total area of the wire cross-section, in inches. WIRE ROPES. 124a For a rope of 19 wires to the strand the diameter of each wire is about one- fifteenth (exactly ) of the diameter of the rope. That is, if d = diameter of rope, a = and by substituting this in the above formula S b E Ad 15.527/ 15.52’ The modulus of elasticity for the different kinds of wire is given different values by different authorities. Mr. Sederholm uses 29,400,000 in his formula and diagram, and Mr. Hewitt 28,500,000, the same modulus being used for the different materials of which ropes are made. The cross-section of metal A in a wire rope is approximately .4 d 2 , or it may be more accurately calculated by multiplying the cross-section of each wire, as given by a wire table, by the number of wires in the rope. Find the bending stress in a 19-wire, cast-steel hoisting rope 2 in. in diam- eter, winding on an 8-ft. drum, if A — .4 d 2 , and E = 29,400,000, „ 29,400,000 X 23 X .4 S b = — . . ^ . . ~~ - . = 31.51 tons. is 124 tons, and if 10 X 15.52 X 96 X 2,000 The approximate breaking stress for such a rope 124 we assume a factor of 3, — = 41+ tons for the safe working stress, and O 41 — 32 = 9 tons, for the safe lifting load under the given conditions. The diagram given on page 125 is based on the above formula. Mr. Wm. Hewitt, of the Trenton Iron Co., has given a similar but more complicated formula for the bending stress, which is supposed to give some- what more accurate results, as he has introduced terms which allow for the actual radius of the bend at the outside fiber of the rope, while the Sederholm formula assumes the radius of the bend to be the radius of the sheave. Mr. Hewitt’s formula is as follows: EA & b — 2.06 ~ + C in which S b = E = bending stress, in pounds; modulus of elasticity (28,500,000); A — aggregate area of wires, in square inches ; R te radius of drum or sheave, in inches ; d = diameter of individual wires, in inches; C = a constant depending on number of wires in strands. The values of d and C are : 7-Wire Rope 19-Wire Rope d = h diameter of rope d = T V diameter of rope C = 9.27 C = 15.45 For 12-wire and 16-wire ropes the values are intermediate in proportion to the number of wires In the case of ropes having strands composed of dif- ferent sizes of wires, take the larger of the outer layer for the value of d. Mr. Hewitt assumes one-third of the approximate breaking stress as the maximum safe stress and uses 28,500,000 for the modulus of elasticity. If the problem given under the Sederholm formula is worked out by the Hewitt formula the safe working load will be 11£ tons, while the table on pages 120 and 121 gives 24.8 tons. * The Sederholm diagram on page 125 gives for a load of 24.8 tons a sheave between 16 and 17 ft. diameter, the Sederholm formula gives a sheave of 15 ft. in diameter, while the table on pages 120 and 121 gives 8 ft. It is evi- dent that there is a wide difference of opinion among the wire-rope authori- ties and a good opportunity for experimental work along this line. In using the Sederholm or Hewitt formulas there are two unknown quantities, the diameter of the rope d and the diameter D or radius R of the drum, d varies inversely as D, that is, for a given load the smaller d is taken the larger D must be to give the same conditions of safety. If we could assume a certain ratio between S h and S t in the* formula S.—- S b + Si the problem could be easily solved, but an examination of this ratio in a number of cases where good results have been obtained from S S 2 hoisting ropes shows this ratio to vary from ^ = 1 to b b ts b S 1 mission of power by wire ropes, Mr. Hewitt assumes ~ = -, but this relation will scarcely hold in a hoisting problem, and the above problem must be solved by the cut-and-try method. = Inthetrans- 5 124b WIRE ROPES. Wear of Wire Ropes— The deterioration of wire ropes may he either external or internal, and may be due (1) t0 abra ^°£’ t ^ Ue o i 0 t o h the U internal the outside surface of the rope against other objects, or the internal chafing of the wires composing the strands against one another, (2) to iniurv g from overloading, to shock due to sudden starting of the load, or to reDeated ^ndings about too sharp angles or over sheaves or rollers of too small a diameter for the size of the rope; (3) to rust or corrosion of the wi e from acid waters or to decay of the hemp cores. As a result of abrasion, the wires in a rope are either flattened or torn ar»art With properly designed drums and head-trame and properly placed sheaves a hofithig rope is but slightly abraded, and the wear is due chiefly S hendina or to overloading. A haulage rope is subjected to constant ahrasionin passta° over rollers and sheaves and from dragging along the hottom and S of the haulage wavs and from the grips. It is also often subject to severe shocks and abrasion from the lashing or vibration when “‘Vhewea? a£§“ua rope increases as its velocity is increased; hence, conditiZs lermittfng?it is better to increase the output by increasing the load within allowable limits rather than by increasing the velocity of “Inspection of Ropes ,_The life of a hoisting rope. depends not only onits duality but also on the conditions under which it is used and en.the eare- fulness'of the engineer in handling the load hoisUng ropes are nffpn and at regular intervals. At some mines the hoisting ropes aie insnected everv morning before lowering the men. The cage is slow y lowered and then raised, each rope being carefully examined b> an insnector to detect any broken wires. Particular attention should be given to the nart of the rope where it is attached to the socket at the cage, r»art is more subject to corrosion and sharp bending than any other. When tlm core fails at any noint the rope should be discarded at once, usthe wires are likely to kink and break internally as the rope passes over the ^sheave. At some mines hoisting ropes are discarded at regular intervals, whether while the rone is run will indicate loose wire ends. . Lubrication of Ropes -Mine water has a very corrosive action on wire comfngta YoXc'I 1 whh n thl "/of the W °For MstoVroP>es"one bushel of freshly slacked lime to one barrel of pine nr eoAl tar makes a good lubricant; with pine tar, which contains no acid, tallow mav be used instead of lime. Another mixture contains tar, summer oil^xl™ greas^and a fittle pulverized mica, mixed to such a consistency that it wifi penetrate thoroughly between the wires and will n 9 t dry ? h strip off The lubricant should not be thick enough to render difficult the thorough inspection of the rope, and all lubricants of this ^ature should be nse^smrin^lv after the first application, as the rope should be kept clean and SfS Graphite is also used for the purpose. Lubricants may he applied bv running the engine slowly and allowing the rope to pass through a bunch of waste saturated with lubricant, by ruling the lubricant into the rone bv means of a brush, or by pouring the oil into the groove oi tbe sheaveas tL ropeis run slowly ba6k and forth. A new hoisting rope should be passed through a bath of hot lubricant and thus be thoroug y 1Ub HaSla^e roues are not usually lubricated as thoroughly as hoisting ropes on Account of ?he grease causing slipping of grips and gathering of dirt and dusl but they can be treated with raw linseed oil thickened with lamp black boiled ^vith an equal portion of pine tar, and the mixture applied while hot. Ordinary black oil, such as is used to oil mine cars and hoisting rones can be used on haulage ropes where no friction grips are emplo>ed. These mixtures^ if fluid can be poured on the rope as it is run over the Theave^r appUed from a leather-lined box filled with oil. Patent lubricants known’ as cable shields or rope fillers, which fill the interstices between the strands, are often used on tail and mam ropes. WIRE ROPES. 125 PROPER WORKING LOAD 126 WIRE ROPES. Starting Strain on Hoisting Rope.— In selecting a hoisting rope, due allow- ance must be made for the shock and extra strain imposed on the rope when the load is started from rest. Experiments made by placing a dynamometer between the rope and the cage have shown that starting stress may be from two to three times the actual load. Experiment 1. Strain in Rope. Pounds. Empty cage, lifted gently Empty cage, started with 2k in. of slack rope Empty cage, started with 6 in. of slack rope . Empty cage, started with 12 in. of slack rope 4,030 5,600 8,950 12,300 Experiment 2. Strain in Rope. Pounds. Cage and loaded cars, as weighed Cage and loaded cars, lifted slowly and gently Cage and loaded cars, started with 3 in. of slack rope Cage and loaded cars, started with 6 in. of slack rope Cage and loaded cars, started with 9 in. of slack rope 11,300 11,525 19,025 24,625 26,850 Horsepower of Manila Ropes. ( Link-Belt Engineering Co.) Diam. of Rope. Weight per Foot. Breaking Strain. Working Strain. 1,000 Ft. per Min. 2,000 Ft. per Min. 3,000 Ft. per Min. 4,000 Ft. per Min. 5,000 Ft. per Min. H.P. Tens. Wt. H.P. Tens. Wt. H.P. Tens. Wt. H.P. Tens. Wt. H.P. Tens. Wt. I 0.15 4,000 121 2* 90 4* 90 6* 80 7* 80 8* 70 * 0.18 5,000 151 2| 110 5* 110 7* 100 9* 100 10* 90 7 8 0.27 7,500 227 4* 170 8* 170 11* 160 14* 150 16 130 1 0.33 9,000 272 5 200 10 200 14 180 17* 170 19 150 1* 0.45 12,250 371 7 280 13* 270 19 250 23* 230 26 210 1* 0.50 14,000 424 8 320 15* 310 22 290 27 270 29* 240 if 0.65 18,062 547 10* 410 20 400 28* 370 34* 350 38* 310 1* 0.73 20,250 613 11* 460 22 440 31* 420 39 390 43* 350 H 0.82 25,000 760 14* 570 27* 550 39* 520 49 490 554 448 1* 1.08 30,250 916 17 680 33* 660 47* 630 58* 580 64* 520 2 1.27 36,000 1,000 20* 810 40 790 56* 740 69* 670 77* 620 WIRE-ROPE FASTENINGS. Thimble spliced, in ordinary style, is shown in Fig. 1 (a). In this method, the wires, after being frayed out at the end and the rope bent around the thimble, are laid snugly about the main portion of the rope and securely fastened by wrapping with stout wire, the extreme ends that project below this wrapping being folded back, as shown. Another style of thimble splicing is shown in Fig. 1(5). In this case the strands are interlocked as in splicing, and the joint is wrapped with wire as in the former method. The socket fastening is sho wn*in Fig. 1 (c). The hole in which the rope end is fastened is conical in shape. The rope is generally secured by fraying out the wires at the end, the interstices being filled up with spikes driven in tightly. The whole is finally cemented by pouring in molten Babbitt metal. This makes a much neater fastening than either of thos6 shown in (a) and (5), but it does not possess anything like as much strength. The thimble possesses a serious disadvantage; it is usually made of a piece of curved metal bent around into an oval shape, WIRE-ROPE SPLICING. 127 Fig. 1. ns shown in (a) and (6), with the groove, in which the rope lies, outside, the ends coming together in a sharp point. When weight is placed on the rope the strain on the thimble is apt to cause one end to wedge itself beyond or past the other, and with its sharp edge it cuts the strands in the splice Mr. William Hewitt, of Trenton, N. J., while testing the strength of wire ropes, discovered this tendency, and experimented with sockets with the idea of devising some method of fastening the rope securely in the socket. He found that by adopt- ing the following plan he secured good, results: The wires, after being frayed out at the end, were bent upon themselves in hook fashion, the prongs of some being longer than others, so that the bunch would conform to the conical aperture of the socket, and the melted Babbitt metal was finally run in as usual. The rope was subjected the a socket The sfmpHcUy of this method commends itself to practical men. . RAPID METHOD OF SPLICING A WIRE ROPE.* The only tools needed are a cold cutter and hammer for cutting and trimming- the strands, and two needles 12 in. long, made of good steel and tapered'ovaUy toa point. Cut off the ends of the ropes to be ^phcedand unlav three adjacent strands of each back 15 ft., cut out the nemp center to this point and relay the strands for 7 ft. and cut thenroff. Pull the ropes by each other until they have the position shown m Fig. 2 (a), cut off a and d' 5 and c', Fig. 2 (6), making their lengths approximately 10 and 12£ ft respectively, measured from the point where the hemp centers were^cut. Pllce theses together, Fig. 2 (O^unlay \ mp *. lfc'?Fi| n 2 (hj^SimilOTlyl /, it until the rope appears as in 2 (c). Next run the u Hemp Center strands into the middle of (a> the rope. To do this, cut (b) /'«■' b Fig. 2. off the end of the strand e', Fig. 2 (c), so that when it is put in place it will just reach to the end x of the hemp core, and then push _ the needle A , , Fig. 2 1(c) through the rope from the under side, leaving two strands at the front of the needle, as shown. Push the needle B through from the upper side and as close to the needle A as possible, leaving the strands e and e between them; place the needle A on the knee and turn the needle B around with the coil of the rope, and force the strand e' into the center of the rope. Repeat this # W. H. Morris, “ Mines and Minerals,” September, 1898. WIRE ROPES. WIRE-ROPE SPLICING. 129 ODeration with the other ends and cut them off* so that the ends coming together in the center of the rope will butt against each other as nearly as possible. . ORDINARY LONG SPLICE. Tools Reauired— One pair wire nippers, for cutting off strands; one pair nliers for pulling through and straightening ends of strands; two niarline- snikes one round and one oval, for opening strands; one knife to cut hemp center- two clamps, to untwist rope to insert ends of strands, or, m place of them two short hemp-rope slings, with a stick for each as a lever; a wooden mallet and some rope twine. Also, a bench and yise are handy. The length of the splice depends on the size of the rope. The larger ropes require the longer splices. The splice of ropes from f hi. to * m. m diameter should not be less than 20 ft.; from ¥ m. to 1 ¥ in., 30 ft., and from l a in. UP, To splice a rope, tie each end with a piece of cord at a distance equal to one-half the length of the splice, or 10 ft. back from the end, for a $ rope, after which unlay each end as far as the cord. Then cut out the hemp center and bring the two ends together as close as possible, placing the strands of the one end between those of the other, as shown m Fig. 3 (a). Now remove the cord k from the end M of the rope, and unlay any strand, as a, and follow it up with the strand of the other end M' of the rope that corresponds to it as a /P Fig- 3 (a) About 6 in. of a are left out, and a is cut off about 6 m from the rone thus leaving two short ends, as shown at P in Fig. 3 (h), which must be tied for the present by cords as shown. The cord k should again be wound around the end M of the rope, Fig. 3 (a), to prevent the unraveling of the strands- after which remove the cord k' on the other or if end of the rope, and unlay the strand 6; follow it up, as above, with the strand b , leaving the ends out, and tying them down for the present, as before described m the case of strands a and a ', see Q, Fig. 3 (6) ; also, replac ie the cord fc for the same purpose as stated above. Now, again remove the cord k and unlay the next strand as c, Fig. 3 (a), and follow it up with c', stopping, however, this time within 4 ft. of the first set. Continue this operation with the remaining 6 strands stopping 4 ft. short of the preceding set each time. The strands are now in their proper places, with the ends passing each other at intervals of 4 ftas shownin Fig. 3(c). To dispose of the loose ends, clamp the rope m a vise at the left of the strands a and a', Fig. 3 (c), and fasten a clamp to the rope at the right of these strands; then remove the cords tied around the rope that hold these two strands down; after which turn the clamp in the oppo- site direction to which the rope is twisted, thereby untwisting the rope, as shownin Fig 3 (d) . The rope should be untwisted enough to allow its hemp cores' to be pulled out with a pair of nippers. Cut off 24 in. of the hemp core 12 in at each side from the point of intersection of the strands a and a,and push the tSds ofthe strands P in their place as shown in Fig. 3 (d). Then allow the rope to twist up to its natural shape, and remove the clamps. After the rope has been allowed to twist up, the strands tucked m generally bulge out somewhat. This bulging may be reduced by lightly tapping the bulged part of the strands with a wooden mallet, which will force their ends farther into the rope. Proceed in the same manner to tuck m the other ends of the strands. CHAINS. The links of iron chains are usually made as short as is consistent with easy play, so as to make them less liable to kink, and also to prevent bending when wound around drums, sheaves, etc. . ■ . , . « The weight of close-link chain is about three times the weight of bar from which it is made, for equal lengths. , ' . , . , Karl von Ott, comparing weight, cost, and strength of three materials, hemp iron wire, and chain iron, concludes that the proportion between cost of hemp rope, wire rope, and chain is as 2 : 1 : 3, and that, therefore, for equal resistances, wire rope is only half the cost of hemp rope, and a third Chains of warranted superior iron will stand 25 } more strain before breaking The report of the U. S. Test Board, 1881, shows that the ultimate strength of chains may be taken at 1.6 that of the iron from which the links are made. 130 hydrostatics. The strength of chains varies, owing to the nature of the iron from which they are made, and their mechanical construction. The following table is approximately correct for ordinary iron chains: Table of Weight an© Strength of Chains. Diameter of Weight of Diameter of Weight of Rod of Which the Links Are Made. Chain per Running Foot. Working Strength. Tons. Breaking Strain. Tons. Rod of Which the Links Are Made. Chain per Running Foot. Working Strength. Tons. Breaking Strain. Tons. Inches. Pounds. Inches. Pounds. t 3 s ■ A •4 h T5 1 ll .325 .19 .773 § 7.10 4.40 16.80 .579 .36 1.37 it 8.14 5.00 19.32 .904 .45 2.14 1 9.26 5.71 22.00 1.30 .85 3.09 11.70 7.23 26.44 1.78 1.09 4.20 li 14.50 9.00 32.64 2.31 1.43 5.50 if 17.50 10.80 39.42 2.93 1.80 6.96 l£ 20.80 13.00 47.00 3.62 2.23 8.58 if 24.40 15.24 55.14 4.38 2.70 10.39 n 28.40 17.65 63.97 1 6 3 5.21 3.21 12.36 if 32.60 20.27 73.44 4 13 TS 6.11 3.80 14.42 2 37.00 23.10 83.55 HYDROSTATICS. Hydrostatics treats of the equilibrium of liquids, and of their pressures on the walls of vessels containing them; the science depends on the way in which the molecules of a liquid form a mass under the action of gravity and molecular attraction, the latter of which is so modified in liquids as to give them their state of liquidity. While the particles of a liquid cohere, they are free to slide upon one another without the least apparent friction; and it is this perfect mobility that gives them the mechanical properties considered in hydrostatics. . The fundamental property may be thus stated: When a pressure is exerted on any part of the surface of a liquid , that pressure is transmitted undiminished to all parts of the mass , and in all directions. This is a physical axiom, and on it are based nearly all the principles of hydrostatics. Equilibrium of Liquids.— This is a property of liquids that can be easily demonstrated, and examples are frequently seen. Thus, if two barrels are connected at the bottom with a pipe, and water is poured in one until it reaches within a foot of the top, the water in the other will be found to have attained the same height. Pressure of Liquids on Surfaces. — The general proposition on this point is as follows* The pressure of a liquid on any surface immersed m it is equal to the weiqht of a column of the liquid whose base is the surface pressed , and whose heiqht is the perpendicular depth of the center of gravity of the surface below the surface of the liquid. The pressure thus exerted is independent of the shape or size of the vessel or cavity containing the liquid. The pressure of a liquid against any point of any surface, either curved or plane, is always perpendicular to the surface at that point. At any given depth the pressure of a liquid is equal in every direction, and is in direct proportion to the vertical depth below the surface. The weight of a cubic foot of fresh water, at ordinary temperature of the atmosphere, that is, from 32° F. to 80° F., is usually assumed at 62.5 lb. This is a trifle more than the actual weight, but is sufficiently close for purposes of calculation. . . f « To Find the Pressure Exerted by Quiet Water Against the Side of a Gangway or Heading —Multiply the area of the side in square feet by the perpendicular distance from the surface of the water to a point equidistant between the top and bottom of the submerged heading or gangway, and multiply the product bv 62.5. The result will be the pressure in pounds, exclusive of atmospheric pressure. This latter need not be considered in ordinary mining work. HYDROSTATICS . 131 Example.— If an abandoned colliery, opened by a slope on a pitch of 25° and 100 yd. long, is allowed to fill with water, what is the average pressure exerted on each square foot of the lower rib of the gangway, assuming that the gangways were driven dead level, and that the length of the slope was measured to a point on the lower rib equidistant between top and bottom of gangway. We here have a perpendicular height of water = 300 X sine of 25° = 126.78 ft. Then, the pressure on each square foot of the lower rib of gangway = 126.78 X 62.5 lb., or the weight of 1 cu. ft., or a pressure on each square foot of surface of 7,923.75 lb., or over 3i gross tons. The total pressure exerted along the gangwav may readily be found by multiplying the 7,923.75 lb. by the number of square feet of the lower rib against which it rests. To find the total pressure of quiet water against and perpendicular to any surface whatever, as a dam, embankment, or the bottom, side or top of any containing vessel, water pipe, etc., no matter whether said surface be vertical, horizontal, or inclined; or whether it be flat or curved; or whether it reach to the surface of the water or be entirely below it: Multiply the area, in square feet , of the surface pressed, by the vertical depth in feet of its center of gravity below the surface of the water, and this product by 62.5. The result will be the pressure in pounds. Thus, assuming that in the annexed three figures the depth of water in each dam is 12 ft., and the wall or embankment is 50 ft. long, then in Fig. 1 the total pressure will equal 12 X 50 X 6 X 62.5 ==, 225,000 lb. In Figs. 2 and 3 the walls or embankments, being inclined, expose a greater surface to pressure, say 18 ft. from A to B. Then the total pressure equals 18 X 50 X 6 X 62.5 = 337,500 lb. Now, the results obtained are the total pressures without regard to direction. In Fig. 1 the total pressure calculated, or 225,000 lb., is hori- zontal, tending either to overturn the wall or make it slide on its base. The center of pres- sure is at C, or one-third of the vertical depth from the bottom. In Fig. 2 the pressure is exerted in two directions; one pressure, acting horizontally, tends to overthrow or slide the wall, while the other, acting vertically, tends to hold it in place. In Fig. 3 the pressure is also exerted in two directions; one pressure, acting horizontally, tends to overthrow or slide the wall, while the other tends to lift. , , _ . _ So long as the vertical depth of water remains the same, the horizontal pressure remains the same, no matter what inclination is given the wall. Thus, in Figs. 2 and 3, the horizontal pressure is the same as in Fig. 1, or 225,000 lb. ^ ^ The total pressure of the water is distributed over the entire depth of the submerged part of the back of the wall, and is least at the top, gradually increasing toward the bottom. But so far as regards the united action of every portion of it, in tending to overthrow the wall, considered as a single mass of masonry, incapable of being bent or broken, it may all be assumed to be applied at C, which is one-third of the vertical depth from the bottom in Fig. 1, or, what is the same thing, one-third of the slope distance from the bottom in Figs. 2 and 3. No matter how much water is in a dam or vessel, the pressure remains the same, so long as the area pressed and the vertical depth of its center of gravity below the level surface of the water remains un- changed. Thus, if the water in dam shown in Fig. 1 extended back 1 mile, it would exert no more pressure against the wall than if it extended back only 1 ft. In any two vessels having the same base, and con- taining the same depth of water, no matter what quantity, the pressures on the bases are equal. Thus, if Figs. 4 and 5 have the same base and be filled with water to the same depth, the pressure on the bases Will be equal. This fact, that the pressure on a given surface, at a given Fig. 4. Fig. 5. 132 HYDROSTATICS. depth, is independent of the quantity of water, is called the hydrostatic P<1 As the pressure of water against any point is at right angles to the surface at that point, it follows that props or other strengthening material for the strengthening of such structures as a sloping dam, should be so placed as to offer the greatest resistance in a line at right angles to the sloping surface, and these supports should be strongest and closest together at the bottom. For the same reason, the hoops on a circular tank should be strongest and closest at the bottom. . ... . . Transmission of Pressure Through Water-Water, in common with other Kauids possesses the important property of transmitting pressure equally in 4 all directions. Thus, if a vessel is constructed with two cylinders, the area of one being 10 sq. in., and that of the other 100 sq. in., and the vessel is filled with water (Fig. 6), and pistons fitted to the cylinders, a pressure of 100 lb. applied at the smaller will balance 1,000 lb. at the larger. This is the principle of the hydrostatic press. Air and other gaseous fluids transmit pressure equally in all directions, like liquids, but not as rapidly. To Find the Pressure on a Plane Surface at Any Given Depth of Water.— For pounds per square inch, multiply depth in feet by .434. For pounds per square foot, multiply depth in feet by 62.5. For tons per square foot, multiply depth in feet by .0279. The pressure per square foot at different depths increases directly as the depths. The total pressure against a plane 1 ft. wide at different depths increases as the square of the depths. Pressure in Pounds per Sq. Ft. at Different Vertical Depths, and Also the Total Pressure Against a Plane 1 Ft. Wide Extending Vertically From the Surface of the Water to the Same Depths. Fig. 6. Depth. Pressure. Pouuds Total Pressure. Depth. Pressure. Pounds Total Pressure. Depth. Pressure. Pounds Total Pressure. Feet. per Sq. Ft. Pounds. Feet. per Sq. Ft. Pounds. r cci. per Sq. Ft. Pounds. i 62.5 31 27 1,687 22,781 65 4,062 132,025 X 2 125 125 28 1,750 24,500 70 4,375 153,124 3 187 281 29 1,812 26,281 75 4,687 175,779 4 250 500 30 1,875 28,125 80 5,000 200,000 K 312 781 31 1,937 30,031 85 5,312 225,775 o Q 375 1,125 32 2,000 32,000 90 5,625 253,124 7 437 1,531 33 2,062 34,031 95 5,937 282,025 i g 500 2,000 34 2,125 36,125 100 6,250 312,500 9 562 2,531 35 2,187 38,281 110 6,875 378,124 10 625 3,125 36 2,250 40,500 120 7,500 450,000 11 687 3,781 37 2,312 42,781 130 8,125 528,100 12 750 4,500 38 2,375 45,125 140 8,750 612,496 13 812 5,281 39 2,437 47,531 150 9,375 703.116 14 875 6,125 40 2,500 50,000 160 10,000 800 j 000 15 937 7,031 41 2,562 52,531 170 10,625 903,100 16 1,000 8,000 42 2,625 55,125 180 11,250 1,012,496 17 1,062 9,031 43 2,687 57,781 190 11,875 1,128,100 18 1,125 10,125 44 2,750 60,500 200 12,500 1,250,000 19 1,187 11,281 45 2,812 63,281 225 14,062 1,582,025 20 1,250 12,500 46 2,875 66,125 250 15,625 1,953,100 21 1,312 13,781 47 2,937 69,031 275 17,187 2,363,275 22 1,375 15,125 48 3,000 72,000 300 18,750 2,812,500 23 1,437 16,531 49 3,062 75,031 350 21,875 3,828,100 24 1,500 18.000 50 3,125 78,125 400 25,000 5,000,000 25 1,562 19,531 55 3,437 94,531 450 28,120 6,328,100 26 1,625 21,125 60 3,750 112,500 500 31,250 7,812,500 Pressure of Water in Pipes.— As water exerts a pressure equally in al. directions, it is important that in pipe lines the pipe should be sufficiently thick to assure strength enough to resist a bursting pressure. In ordinary H YD ROST A TICS. 133 practice, the thickness of cast-iron water pipes of different bores is calculated by Mr. J. T. Fanning’s formula, given in his Hydraulic Engineering, which is as follows: . _ (pressure in lb. per sq. in. + 1 00) X bore in in. Thickness m inches — .4 X ultimate tensile strength + .333 bore in in.\ Too )' This formula, worked out for different heads and different sizes of bore, yields the following results: Thickness of Pipe for Different Heads and Pressures. Head in Ft 50 100 200 300 500 1,000 Pressure in Lb. 21.7 43.4 86.8 130 217 434 per Sq. In. Bore. Inches. Thickness of Pipe. Inches. 2 .36 .37 .38 .39 .42 .48 3 .37 .38 ■ .40 .42 .45 .54 4 .39 .40 .42 .45 .50 .61 6 .41 .43 .47 .50 .57 .75 8 .45 .47 .52 .57 .66 .90 10 .47 .50 .56 .62 .74 1.04 12 .49 .53 .60 .67 .82 1.18 16 .55 .60 .70 .79 .98 1.46 18 .57 .63 .74 .85 1.06 1.60 20 .61 .67 .79 .91 1.15 1.75 24 .66 .73 .87 1.02 1.30 2.03 30 .74 .83 1.01 1.19 1.55 2.46 36 .82 .93 1.15 1.36 1.80 2.88 48 .98 1.13 1.42 1.70 2.28 3.73 In the above table, the ultimate tensile strength of cast iron is taken at 18 000 lb. per sq. in. The addition of 100 lb. to the pressure is made to allow for water ram. The valves of water pipes should he closed slowly , and the necessity of this increases as the pipes increase in diameter. If this rule is not observed, the momentum of the running water is arrested suddenly, and a great pressure is created against the pipes in all directions, and through- out the entire length of the line above the valve, even if it be many miles, and there is danger of their bursting at any point. For this reason, stop- gates are shut by screws, because they prevent any very sudden closing; but in pipes of large diameters, even the screws must be worked very slowly to ^^Com prelss fifiUty of Liquids.— Liquids are not entirely incompressible, but they are so nearly so, that for most purposes they may be considered as incompressible. The bulk of water is diminished about by a pressure of 324 lb per sq. in., or 22 atmospheres; varying slightly with its temperature. It is perfectly elastic, regaining its original bulk when the pressure is r emo v ed Construction of Dams in Mines.— Dams may be constructed in mines, either to isolate a portion of the workings so that they can be flooded to extinguish fires or, in cases where an extremely wet formation has been penetrated, it is sometimes expedient to construct a dam so as to prevent the water from flowing into the workings. Mine dams should be of sufficient strength to resist any column of water that will be likely to come against them. The dam should be arched toward the direction from which the pressure comes, and should be given a good firm bearing in both walls and in the floor and roof Fig 7 illustrates a brick dam that was constructed in Kehley’s Run Colliery at Shenandoah, Pa., to isolate a portion of the seam so that it might 134 HYDROSTATICS. be flooded to extinguish a mine fire. This is one of the largest mine dams that has ever been constructed. It is composed of three brick arches, each having a thickness of 5 ft., that are placed one against the other so that they act as one solid structure. The gangway at this point is about 20 ft. wide, and the distance to the next upper level is about 119 ft. It was intended that this should be the maximum head of water that the dams would ever \ have to resist, though they were made sufficiently strong to resist a head of water reaching to the surface. The separate walls were constructed one at a time, and the cement allowed to set before the next wall was placed. The back wall was carried to a greater depth and height than the others, so as to make sure of the fact that all slips or partings had been closed. The total pressure upon the dam when the water was in the mine was about 70,000 lb. per sq. ft. Dams constructed to permit the flooding of a mine usually require no passages through them, but where dams are constructed to confine the water to certain parts of the workings, and so reduce pumping charges, it may be necessary to provide both manways and drain pipes through the Fig. 7. Fig. 8. dams. Fig. 8 illustrates a plan and cross-section of a dam in the Curry Mine, at Norway, Mich. (“Mines and Minerals,” Vol. 18, page 177; Trans. A I. M. E., XXVII, 402), constructed to keep the water that came from some exploring drifts out of the mine workings. As originally constructed, it consisted of a sandstone dam 10 ft. thick and arched on the back face with a radius of 6 ft. A piece of 20" pipe provided a manway through the masonry and was held in place by three sets of clamps and bolts passing through the stonework. A 5" drain pipe was also carried through the dam and secured by clamps. When the pressure came upon the dam it was found to leak, so the water was drained off and a 22" brick wall built 2 ft. 4 in. back of the dam, the space between being filled with concrete, and the manway and drain pipe extended through the brick wall. Before closing the drain pipe, horse manure was fastened against the face of the brick wall by means of a plank partition. After this the manway and drain pipe were closed, and when the pressure came on, the dam was found to leak a small HYDRAULICS. 135 amount, but this soon practically ceased, showing that the manure had closed the leaks. A gauge in the head of the manway on this dam showed a pressure of 211 lb., which corresponded to a static head of 640 ft. of water. The total pressure against the dam was something over 800 tons, which it successfully resisted. HYDRAULICS. Hydraulics treats of liquids in motion, and in this, as in hydrostatics, water is taken as the type. In theory its principles are the same as those of falling bodies, but in practice they are so modified by various causes that they cannot be relied on except as verified by experiment. The discrepancy arises from changes of temperature that vary the fluidity of the liquid, from friction, the shape of the orifice, etc. As we shall deal with water only, the first cause may be thrown aside as of little account. In theory the velocity of a jet is the same as that of a body falling from the surface of the water. To Find the Theoretical Velocity of a Jet of Water.— Let v = the velocity, g = the acceleration of gravity (32.16 ft.), and d = the distance of the orifice below the surface of the water. Then, v = V 2 g d, or v = the square root of twice the product of g x d. Example.— The depth of water above the orifice is 64 ft.; what is the velocity ? Substituting 64 for d , and 32.16 for g , we have, v = ]/ 2 X 32.16 X 64, or 64.16. To Find the Theoretical Quantity of Water Discharged in a Given Time.— Multi- ply the area of the orifice by the velocity of the water, and that product by the number of seconds. Example.— What quantity of water will be discharged in 5 seconds from an orifice having an area of 2 sq. ft., at a depth of 16 ft.? \/ 2 X 32.16 X 16 X 2 = 64.16 cu. ft,, or the amount discharged in 1 second, and in 5 seconds the amount will be 5 X 64.16 = 320.8 cu. ft. The above rules are only theoretical, and are only useful as foundations on which to build practical formulas. Flow of Water Through Orifices.— The standard orifice, or an orifice so arranged that the water in flowing from it touches only a line, as would be the case in flowing through a hole in a very thin plate, is used for the measurement of water. The contraction of the jet, which always occurs when water issues from a standard orifice, is due to the circumstance that the particles of water as they approach the orifice move in converging directions, and that these directions continue to converge for a short distance beyond the plane of the orifice. This contraction causes only the inner corner of the orifice to be touched by the escaping water, and takes place in orifices of any shape, its cross-section being similar to the orifice until the place of greatest contraction is passed. Owing to this contraction, the actual discharge from an orifice is always less than the theoretical discharge. The Coefficient of Contraction. — The coefficient of contraction is the number by which the area of the orifice is to be multiplied in order to find the area of the least cross-section of the jet. In this way by experiment this coeffi- cient has been found to be about .62 (Merriman’s “Hydraulics”); or, in other words, the minimum cross-section of the jet is 62$ of the cross-section of the orifice. The Coefficient of Velocity.— The coefficient of velocity is the number by which the theoretical velocity of flow from the orifice is to be multiplied in order to find the actual velocity at the least cross-section of the jet. This may be taken for practical work as .98; or, in other words, the actual flow at the contracted section is 98$ of the theoretical velocity. The Coefficient of Discharge — The coefficient of discharge is the number by which the theoretical discharge is to be multiplied in order to obtain the actual discharge. This has been found by thousands of experiments to be equal to the product of the coefficients of contraction and velocity, and for practical work it may be taken as .61; or, the actual discharge from standard orifices is 61$ of the theoretic discharge. 136 HYDRAULICS. Note —While the coefficients for standard orifices with sharp edges have been determined fairly close, those for the more complicated cases of weirs, and especially for the flow of water through long pipes, are simply the nearest approximation to the truth that it has been possible to obtain. In all cases the coefficient should be one that has been determined under con- ditions similar to those in the problem in hand. For instance, it is not prac- ticable to use the coefficient for small pipes m solving problems relating to large ones, or for short pipes in solving problems relating to long ones. Suppression of the Contraction. — When a vertical orifice has its lower edge at the bottom of a reservoir, the particles of water flowing through its lower portion move in lines nearly perpendicular to the plane of the orifice, and the contraction of the jet does not form on the lower side. The same thing occurs in a lesser degree when the lower edge of the orifice is within a dis- tance of three times its least diameter from the bottom. The suppression of contraction will occur on the side if it is placed within a distance of three times its least diameter from the side of a reservoir the suppression of contraction being the greater the nearer the orifice is to the side. By round- ino- the edge of the orifice sufficiently, the contraction can be completely suppressed and the discharge can be increased. As stated before the value of the coefficient of contraction for a standard square-edged orifice is .62, but with a rounded orifice it may have any value between .62 and 1.00, depend- Sff on the degree of rounding. The coefficient of discharge for square- edled orifices has a mean value of .61; this is increased with rounded edges and may have any value between .61 and 1.00, although it is not probable that values greater than .95 can be obtained except by the most careful adtustment of the rounded edges to the exact curve of a completely con- tracted jet. A rounded interior orifice is therefore always a source of error when the object of the orifice is the measurement of the discharge. GAUGING WATER. Water is sold by two methods; i. e., the flowing unit and the capacity unit The flowing unit is a cubic foot per second. In the western part of North America the miners' inch has come into use .quite largely, while in Australia and New Zealand the cubic foot per second is the common measure, Australia ai being x head » and 10 heads of water would be 10 cu ft. oer second regardless of the actual hydrostatic head under which the water was delivered: Water is sometimes sold for irrigation by the capacity unit, that is so much land covered to a certain depth, as, for instance, the acre- foot ” which means that 1 acre has been covered to a depth of 1 foot, or that an amount of 43,560 cu. ft. of water has been furnished. Miners’ Inch -The miners’ inch may be roughly defined as the quantity of water that wili flow in 1 minute through a vertical standard orifice having a section of lsq ! in and a head of 6* in. above the center of the orifice. This ouantitv equals 1.53 cu. ft., and the mean quantity may be taken at, approxi- matelv 15 q cu ft. per minute. The laws or customs defining the miners inch in different districts vary so that the amount of water actually delivered varies from 1.2 to 1.76 cu. ft. per minute, the principal reasons for these varia- tions being the method adopted for measuring, the water where large quan- tities are used" as, for instance, at Smartsville, m California, an opening 4 in. deep 250 in f long with a head’ of 7 in. above the .top edge is said to furnish i non miners’ inches, while it would actually furnish considerably over 1,000. Tu othe? nlaces the size of the opening for measuring the amounts is restricted and may actually furnish less than the rated amount. In Montana the common method of measurement was formerly through a vertical rect- anele TiS hiSi . with a head on the center of the orifice of 4 m. The num- bef of minem’ inches discharged was considered to be the same as the number of linear inches in the length of the orifice; thus, under the given head an orifice 1 in. deep and 60 in. long could discharge 60 miners ^hes. The State Legislature of Montana has now passed a law defining the miners’ inch as the number of gallons of water discharged m a given time, regardless of the character of the openings or methods of measurement. Tffie statement is as follows; “Where water rights, expressed m miners inches hive been granted, 100 miners’ inches shall be. considered equivalent to a flow of 2* cu ft. (18.7 gal.) per second, and this proportion shall be observed in determining the equivalent flow represented by any number of miners’ inches.” MINERS’ INCH. 137 If this amount is reduced to cubic feet per minute, it will be found to be equal to a flow of 1.5 cu. ft. per minute, which is the value given above for the miners’ inch. Duty or Work Performed by a Miners’ Inch of Water.— Few tests have been made in regard to the duty of a miners’ inch of water, but the North Bloomfield mine and the La Grange mine, in California, have carried on a series of experiments extending over several years. At the La Grange mine the observations were carried on simultaneously upon several differ- ent claims, hence parallel dates appear. The accompanying tables give the results of these experiments. In general it is governed by the size, capacity, character of pavement, and grade of sluices, together with the supplv of water. A heavy grade will compensate for a limited supply. With an abundant supply of water and material, the capacity of the sluices, will depend on: First , the character of the material washed; second , the size and minimum grade of the sluices; third , the character of the riffles used. Duty of Miners’ Inch. ( Risdon Iron Works , Evans's Elevator Catalogue.) North Bloomfield Mine. Years. Cubic Yards of Gravel Washed. Miners’ 24-Hour Inches. Grades. Cubic Yards Washed per Miners’ Inch. Cubic Feet of Water Used per Cubic Feet of Gravel Moved. Height of Bank. Remarks. 1870-74 1875 1876 1877 3.250.000 1.858.000 2,919,700 2,993,930 710,987 386,972 700.000 595.000 6^ in. to 12 ft. 6H in. to 12 ft. 6J^ in. to 12 ft. 6J^ in. to 12 ft. 4.60 4.80 4.17 3.86 18 17 20 21 100 ft. 100 ft. 200 ft. 265 ft. Sluices 6 ft. wide, 32 in. deep. Riffles principally blocks (wood), but > rock riffles in tail sluices. The larger portion of the material moved was top gravel. Totals 11,021,630 2,392,959 4.60 18 La Grange Mine. 1874- 76 1875- 76 1874- 76 1875- 78 1880-81 676,968 683,244 284,932 459,570 329,120 624.745 375,155 207,010 302,960 203,325 4 in. to 16 ft. 4 in. to 16 ft. 4 in. to 16 ft. 4 in. to 16 ft. 4 in. to 16 ft. 1.08 1.82 1.37 1.52 1.57 74.0 43.9 58.0 52.0 50.0 10 to 48 ft. 6 ft. 50 to 80 ft. 40 to 50 ft. 10 to 80 ft. Sluices 4 ft. wide and 30 in. deep, > paved with blocks. Totals 2,433,834 1,713,195 1.42 56.0 The right-angled V notch is frequently used for gauging the flow of compara- tively small streams. The notch is usually fitted into a box provided with baffle boards, Fig. 9, or where this is not practicable the water should be so impounded above the notch as to remove all possibility of surface cur- rents producing a perceptible velocity of approach. The distance a of the surface of the water below the top of the box is taken at a point some dis- tance back from the notch (at least 18 to 20 in.), where the surface of the water is unaffected by the flow through the notch. The distance a, sub- tracted from the total depth of the notch H, gives the head h of the water passing over the notch. The discharge in cubic feet per second may be found by the formula _ __ Q = .306 / hP = .306 ft*/ ft, in which Q equals the quantity in cubic feet per minute and h equals the 138 HYDRAULICS. head in inches. The accompanying table gives the discharge in cubic feet per minute through a right-angled V notch, as shown m Fig. 9, for heads varying from 1.05 in. to 12 in. TABLE I. Discharge of Water Through a Right-Angled V Notch. h Head. Inches. Q Quantity per Min. Cu. Ft. h Head. Inches. Q Quantity per Min. Cu. Ft. h Head. Inches. Q Quantity per Min. Cu. Ft. h Head. Inches. Q Quantity per Min. - Cu. Ft. h Head. inches. Q Quantity per Min. Cu. Ft. 1 05 .3457 3.25 5.827 5.45 21.22 7.65 49.53 9.85 93.18 1 10 .3884 3.30 6.054 5.50 21.71 7.70 50.34 9.90 94.37 1 15 .4340 3.35 6.285 5.55 22.20 7.75 51.16 9.95 95.56 1 20 .4827 3.40 6.523 5.60 22.70 7.80 51.99 10.00 96.77 1 25 .5345 3.45 6.765 5.65 23.22 7.85 52.83 10.05 97.98 1 30 5896 3.50 7.012 5.70 23.74 7.90 53.67 10.10 99.20 1 35 .6480 3.55 7.266 5.75 24.26 7.95 54.53 10.15 100.43 1 40 .7096 3.60 7.524 5.80 24.79 8.00 55.39 10.20 101.67 1 45 .7747 3.65 7.788 5.85 25.33 8.05 56.26 10.25 102.92 1 50 .8432 3.70 8.058 5.90 25.87 8.10 57.14 10.30 104.18 .9153 3.75 8.332 5.95 26.42 8.15 58.03 10.35 105.45 1 60 9909 3.80 8.613 6.00 26.98 8.20 58.92 10.40 106.73 * i 65 1.0700 3.85 8.899 6.05 27.55 8.25 59.82 10.45 108.02 1.70 1.1530 3.90 9.191 6.10 28.12 8.30 60.73 10.50 109.31 1.75 1.2400 3.95 9.489 6.15 28.70 8.35 61.65 10.55 110.62 L80 1.3300 4.00 9.792 6.20 29.28 8.40 62.58 10.60 111.94 L85 1.4240 4.05 10.100 6.25 29.88 8.45 63.51 10.65 113.26 1.90 1.5220 4.10 10.410 6.30 30.48 8.50 64.45 - 10.70 114.60 L95 1.6250 4.15 10.730 6.35 31.09 8.55 65.41 10.75 115.94 2^00 1.7310 4.20 11.060 6.40 31.71 8.60 66.37 10.80 117.29 2.05 1.8410 4.25 11.390 6.45 32.33 8.65 67.34 10.85 118.65 2.10 1.9550 4.30 11.730 6.50 32.96 8.70 68.32 10.90 120.02 2.15 2.0740 4.35 12.070 6.55 33.60 8.75 69.30 10.95 121.41 2/20 2.1960 4.40 12.420 6.60 34.24 8.80 70.30 11.00 122.81 2.25 2.3230 4.45 12.780 6.65 34.89 8.85 71.30 11.05 124.21 2.30 2.4550 4.50 13.140 6.70 35.56 8.90 72.31 11.10 125.61 2.35 2.5900 4.55 13.510 6.75 36.23 8.95 73.33 11.15 127.03 2.40 2.7300 4.60 13.890 6.80 36.89 9.00 74.36 11.20 128.45 2.45 2.8750 4.65 14.270 6.85 37.58 9.05 75.40 11.25 129.90 2.50 3.0240 4.70 14.650 6.90 - 38.27 9.10 76.44 11.30 131.35 2.55 3.1770 4.75 15.040 6.95 38.96 9.15 77.49 11.35 132.81 2.60 3.3350 4.80 15.440 7.00 39.67 9.20 78.55 11.40 134.27 A 65 3.4980 4.85 15.850 7.05 40.38 9.25 79.63 11.45 135. / 5 2.70 3.6660 4.90 16.260 7.10 41.10 9.30 80.71 11.50 137.23 2.75 3.8380 4.95 16.680 7.15 41.83 9.35 81.80 11.55 138.73 2.80 4.0140 5.00 17.110 7.20 42.56 9.40 82.90 11.60 140.23 2.85 4.1960 5.05 17.540 7.25 43.30 9.45 84.01 11.65 141.75 2.90 4.3820 5.10 17.970 7.30 44.06 9.50 85.12 11.70 143.28 2.95 4.5740 5.15 18.420 7.35 44.82 9.55 86.24 11.75 144.82 3.00 4.7700 5.20 18.870 7.40 45.58 9.60 87.37 11.80 146 36 3.05 4.9710 5.25 19.320 7.45 46.36 9.65 88.52 11.85 147.91 3.10 5.1780 5.30 19.790 7.50 47.14 9.70 89.67 11.90 149.48 3.15 5.3880 5.35 20.260 7.55 47.92 9.75 90.83 11.95 151.05 3.20 5.6050 5.40 20.730 7.60 48.72 9.80 92.00 12.00 152.64 1 cu. ft. contains 7.48 U. S. gallons; 1 U. S. gallon weighs 8.34 lb. Gauging bv Weirs.— A weir is an obstruction placed across a stream for the nurpose of diverging the water so as to make it flow through a desired chan- nel which may be l notch or opening in the weir itself The term usually applies to rectangular notches in which the water touches only ^he bottom and ends, the opening being a notch without any upper edge. Weirs are of two general classes: weirs with end contractions , Fig. 10 (a), and weirs without GAUGING BY WEIRS. 139 Fig. 9. Let l H h = c Q Q' end contractions , Fig. 10 (6). The crest and edges of the weir with end con- tractions should be sharp, as shown at a , Fig. 10 (c) and (d). The head of water H producing the flow over the weir should be measured at a suffi- cient distance from the crest to avoid the effects of the curve of the surface as it flows over the crest. The water above the weir should be motionless, or if it has any perceptible current toward the weir, this should be deter- mined and taken into account in the formula. Fig. 11 illus- trates a weir constructed across a small stream for measuring its flow. The head is measured from the stake E some distance back of the weir, the top of the stake being level with the crest of the weir B. The discharge over the weir may be calculated from tlje following formula: length of weir in feet; head in feet; velocity with which the water approaches the weir in feet; head equivalent to the velocity with which the water approaches the weir; coefficient of discharge; theoretic discharge in cubic feet per second; actual discharge in cubic feet per second. For weirs with end contractions and a velocity of approach, the actual discharge is Q = 5.347 cl]/ (£T + 1.4 h) 3 . Where the water has no velocity of approach, _ Q = 5.347 cl ]/ H 3 . For weirs without end con- tractions, but with a velocity of approach, the actual dis- charge is ______ Q = 5.347 c l ]/\H + | h) s . Where the water has no velocity of approach, Q = 5.347 c 1 1 /H*. The velocity with which the water approaches the weir may be found by determining the approximate discharge from the stream without any allowance for velocity of approach, and then dividing this discharge in cubic feet per second by the area of the stream in square feet where it approaches the weir, which will give the velocity of approach in feet per second. Having ob- tained the value oft;, ^ ^ the equivalent head h « may be found by the formula h = 0.01555 v-. Since v is small in a properly constructed weir, it is usually neg- lected unless great accuracy is required. The values of coeffi- cients of discharge, as determined from ex- periments for weirs with end contractions, are given in Table II, and for weirs without end contractions in Table III. The values of the coefficients in Tables II and III are given in feet and tenths. Frequently 140 HYDRA VLICS. in measuring water where only a close approximation is required it is desired to take all of the measurement in feet and inches. See Table IV. TABLE II. Values of the Coefficient of Discharge for Weirs With End Contractions. Length of W 7 eir. Feet. Enecnve neau. Feet. 1 .66 i 1 2 3 5 10 | 19 .10 .632 .639 .646 .652 .653 .655 .656 .15 .619 .625 .634 .638 .640 .641 .642 .20 .611 .618 .626 .630 .631 .633 .634 *25 .605 .612 .621 .624 .626 .628 | .629 .30 .601 .608 .616 .619 .621 .624 ' .625 .40 .595 .601 .609 .613 .615 .618 , .620 .50 .590 .596 .605 .608 .611 .615 .617 .60 .587 .593 .601 .605 .608 .613 | .615 ; 70 .590 .598 .603 .606 .612 .614 ftfl .595 .600 .604 .611 .613 •OU 90 .592 .598 .603 .609 .612 1 00 .590 .595 .601 .608 .611 l.V/U 1 20 .585 .591 .597 .605 .610 1 . AAJ 1 40 .580 .587 .594 .602 .609 1.60 .582 I .591 1 .600 .607 TABLE III. Values of the Coefficient of Discharge for Weirs Without End Contractions. Effective Head. Feet. Length of W'eir. . Feet. 19 f 10 1 7 5 ! 4 3 2 10 .657 .658 .658 .659 .lu .15 .643 .644 .645 .645 .647 i .649 .652 [20 .635 .637 .617 .638 .641 I .642 .645 *25 .630 .632 .633 .634 .636 j .638 | .641 .30 .626 .628 .629 .631 .633 ! .636 .639 .40 .621 .623 .625 .628 .630 .633 .636 "'SO .619 .621 .624 .627 .630 .633 .637 .60 .618 .620 .623 .627 .630 .634 .638 .70 .618 .620 .624 .628 .631 .635 .640 "on .618 .621 .625 .629 .633 .637 .643 .oU 00 .619 .622 .627 .631 .635 .639 .645 • «7 \j 1.00 .619 .624 .628 .633 .637 .641 .648 1.20 .620 .626 .632 .636 .641 .646 1.40 .622 .629 .634 .640 .644 L60 .623 .631 .637 .642 .647 L CONVERSION FACTORS. 141 TABLE IV. Weir Table Giving Cubic Feet Discharged per Minute for Each Inch in Length of Weir for Depths From £ In. to 25 In. This table should not be used unless the length of the crest is at least B or 4 times the depth of water passing over the weir, for if this is not the case, there will be serious errors caused by end contractions. Inches. 0 8 1 4 1 £ £ 7 8 0 .01 .05 .09 .14 .20 .26 .33 1 .40 .47 .55 .65 .74 .83 .93 1.03 2 1.14 1.24 1.36 1.47 1.59 1.71 1.83 1.96 3 2.09 2.23 2.36 2.50 2.63 2.78 2.92 3.07 4 3.22 3.37 3.52 3.68 3.83 3.99 4.16 4.32 5 4.50 4.67 4.84 5.01 5.18 5.36 5.54 5.72 6 5.90 6.09 6.28 6.47 6.65 6.85 7.05 7.25 7 7.44 7.64 7.84 8.05 8.25 8.45 8.66 8.86 8 9.10 9.31 9.52 9.74 9.96 10.18 10.40 10.62 9 10.86 11.08 11.31 11.54 ' 11.77 12.00 12.23 12.47 10 12.71 13.95 13.19 13.43 13.67 13.93 14.16 14.42 11 14.67 14.92 15.18 15.43 15.67 15.96 16.20 16.46 12 16.73 16.99 17.26 17.52 17.78 18.05 18.32 18.58 13 18.87 19.14 19.42 19.69 19.97 20.24 20.52 20.80 14 21.09 21.37 21.65 21.94 22.22 22.51 22.79 23.08 15 23.38 23.67 23.97 24.26 24.56 24.86 25.16 25.46 16 25.76 26.06 26.36 26.66 26.97 27.27 27.58 27.89 17 28.20 28.51 28.82 29.14 29.45 29.76 30.08 30.39 18 30.70 31.02 31.34 31.66 31.98 32.31 32.63 32.96 19 33.29 33.61 33.94 34.27 34.60 34.94 35.27 35.60 20 35.94 36.27 36.60 36.94 37.28 37.62 37.96 38.31 21 38.65 39.00 39.34 39.69 40.04 40.39 40.73 41.09 22 41.43 41.78 42.13 42.49 42.84 43.20 43.56 43.92 23 44.28 44.64 45.00 45.38 45.71 46.08 46.43 46.81 24 47.18 47.55 47.91 48.28 48.65 49.02 49.39 49.76 CONVERSION FACTORS. Cubic feet Into Gallons: 1 728 1 cu. ft. = 1,728 cu. in. = gal. = 7.4805194 gal. Gallons Into Cubic Feet: 231 1 United States liquid gal. = 231 cu. in. = — cu. ft. = .133680555 cu. ft. 1| /2o Feet per Second Into Miles per Hour: 3 600 15 1 ft. per sec. = 3,600 ft. per hr. = , or miles per hour. D } Z£5\) ZZ Miles per Hour Into Feet per Second: 5 280 22 1 mi. per hr. = 5,280 ft. per hr. = r, or — ft. per sec. * UjOUi) lv Second-Feet per Day Into Gallons: lsecond-foot, or 7.4805194 gal. per sec. for 1 day, or 86,400 sec. = 646,316.87616 gal. Millions of Gallons Into Second-Feet per Day:j 231 000 000 ] ,000,000 gal. per 24 hr. = r728 X 86 400 CU ’ ft ’ persec -’ or 1.5472286 second-feet. Second-Feet per Day Into Acre-Feet: 1 second-foot flow for 1 day = 86,400 cu. ft. = or 1.983471 acre-feet. 142 HYDRAULICS. Acre-Feet Into Second-Feet Flow for 24 Hours: One acre-foot each 24 hr. = 43,560 cu. ft. each 86,400 sec. = 43 ’--, or second-foot flow for 24 hr. 86,400 ’ 240 Acre-Feet Into Gallons: 1 acre-foot = 43,560 cu. ft. = 43,560 X 1,728 75,271,680 231 ’ 231 or 325,851.428 gal. Millions of Gallons Into Acre-Feet: 1,000,000 United States liquid gal., or 231,000,000 cu. in. = or 133,6 ~ = 3.0688832 acre-feet. 43,560 133,680.555 cu. ft., Second-Feet Into Minute Gallons: Factors: 1 cu. ft. contains 1,728 cu. in.; 1 gal. has a ca Pac“y of 231 cu. iir; 1 second-foot equals [(1,728 - 4 - 231) X 60] gal. per min., or 448.831164 minute- gallons. Minute-Gallons Into Second-Feet: Tf' a ptotis* • 1 ffal contains 231 cu. in.; 1 cu. ft. contains 1,728 cu. in.; 1 gal. per F mh™equal! [(231 4 - 1,728) -*■ 60] second-feet, or .0022280092 second-foot. FLOW OF WATER IN OPEN CHANNELS. Ditches —In the case of hydraulic mining and irrigation, water is usually conveyed through ditches. The ditch line should be carefully surveyed and ail brush and trees removed, and the underbrush cut away and burned, ^^T^e^ftSlowtag^tetters ^ifl be useiTin the formulas for determining the various factors rela tin be j W g en en( j s 0 f canal or ditch, or between two uoints under consideration; ,. I — horizontal length of portion of canal or ditch under consideration; s = slope = ratio - = sin of slope; n = area of water cross-section in square feet; . _ A “ = we t perimeter = portion of outline of cross-section of stream m p contact with channel, in feet; ^ r _ hydraulic radius, or hydraulic mean depth = ratio C’ = coefficient, depending on nature of surface of the ditch; c = coefficient depending on nature of surface of ditch, as determined by Kutter’s formula; v = mean velocity of flow m feet per second; v' = surface velocity of a stream; V x = bottom orune side of a section, the form of which is half a regular hexagon, in feet; , . _ . o = quantity of water flowing, m cubic feet per second; n = coefficient of roughness in Kutter’s formula. The form of ditch and its grade will depend largely on the > amount of water to be conveyed and the character of the soil in the section ll ^der consideration As a general rule, the average flow of water in a ditch should not be less than 2 ft. per second, and under most circumstances should not exceed 4 ft., though in rare cases where the formation is suitable, mean velocities of 5 ft. per second are employed. Sand will deposit from a Sirrent flowing at the rate of H ft. per second, and if the current does not have a velocity of at least 2 ft. per second, vegetation is liable to block the ditch line. „ Safe Bottom Velocity.— The bottom velocity of a stream may be obtained from the average velocity by the following formula: v h = v — 10.87 y rs. The following table gives values of safe bottom and mean velocities, cor responding with certain materials, as given by Ganguillet and Kutter: FLOW OF WATER IN CHANNELS. 143 Material of Channel. Safe Bottom Velocity v b . Feet per Second. Mean Velocity v. Feet per Second. Soft brown earth .249 .328 Soft loam .499 .656 Sand 1.000 1.312 Gravel 1.998 2.625 Pebbles 2.999 3.938 Broken stone, flint 4.003 5.579 Conglomerate, soft slate 4,988 6.564 Stratified rock 6.006 8.204 Hard rock 10.009 13.127 Resistance of Soils to Erosion by Water. — W. A. Burr, “ Engineering News,” February 8, 1894, gives a diagram showing the resistance of various soils to erosion by water. The following values have been selected from Mr. Burr’s work for different kinds of soil: Pure sand resists erosion by flow of 1.10 ft. per sec. Sandy soil, 15 0 clay 1.20 ft. per sec. Sandy loam, 40 0 clay 1.80 ft. per sec. Loamy soil, 650 clay 3.00 ft. per sec. Clay loam, 850 clay 4.80 ft. per sec. Agricultural clay, 950 clay 6.20 ft. per sec Clay 7.35 ft. per sec. Carrying Capacity of Ditches.— Ditches should never be run full, but should be constructed large enough so that they will carry the desired amount of water when from £ to i full. For any given cross-section, the greatest flow will be attained when the hydraulic radius or hydraulic mean depth is equal to one-half of the actual depth of the channel. The cross-section of a ditch or conduit that has the greatest possible carrying capacity is a half circle, and the nearest practical approach to this is a half hexagon. Knowing the cross-section of a ditch, its dimensions may be found by the formula: / 2a X ~ \ 2.598 As the obtuse angle between the side and bottom of the ditch is 120°, the form can be easily laid off. The carrying capacity of ditches generally increases after they have been in use some time, as the ditch becomes lined with a fine scum that closes the pores in the soil and prevents leakage. This may increase the amount to as much as 100. Grade.— The grade of the ditch must be sufficient to create the desired velocity of flow, and depends largely on the character of the material com- posing the surfaces of the ditch. If the surface is smooth, as, for instance, where the ditch is cut through clay or is lined with masonry, the grade can be considerably less than where the surface is rough, or when cut through coarse gravel or when lined with rough stone. In mountainous countries, where the ground is hard, deep narrow ditches with steep grades are gener- ally preferred to larger channels with gentle slopes, as the cost of excavation is considerably less; but steep grades and narrow ditches are suitable only when the banks can resist the rapid flow. In California, grades of from 16 to 20 ft. per mile are used, and 10 ft. per mile is quite common. Water channels of a uniform cross-section should have a uniform grade, otherwise, the flow will be checked in places, which will result in deposits of sand or silt in some portions of the ditch, which are liable to cause the banks to be o ver- flowed and the ditch to be ultimately destroyed. In designing any given ditch, the grade is generally assumed to correspond to the formation of the country and the velocity figured from the grade. In case v is found to be so great that it would cut the banks, it will be necessary either to reduce the grade or to change the form of the ditch so as to reduce the velocity. Ditch banks, when possible, should be composed of solid material, but frequently it is necessary to use excavated material. Where this is the case, care must be taken to see that the material is so placed as to avoid settling 144 HYDRAULICS. sSv iUs beltto build them of masonry, provided the expense is not too Stonework ■ lafd up in. order and carefully bonded together. Sometimes the able innue rnnoh greater average velocity can be attained in a deeD stream * 5 than SaSwC wlthSut causing* an excessive velocity oft^fwateP to “intact with the wet perimeter. For toWBW/ m cases where banks will stand it, it is best to use narrow deep ditches rather than wide flat ditches, though each location has to be tre , a * e ,^/? /f®” rdan th its own s to' 0 i ; dc “ di ‘Vwater“i <: i Chafneto-TheTws^ to toe resistance to the flow may b! expressed by the relation (see page 142 for significance of letters) : ha = c'lpv* or, v = X | ^ X * X r. If C = the formula becomes v = c V' n The coefficient c is usually found by means of Kutter’s formula, one form of which is as follows: * 1 .00155 23 + b — — c = / „ .00155 \ n .5521 + (23 + — ) The values for n, the coefficient of roughness, under various conditions, are as follows: Character of Channel. Clean, well-planed timber ------ fOpan smooth, glazed iron, and stoneware pipes Masonry, smoothly plastered with cement, and for very clean, Unvaried timber, ordinary cast-iron pipe, and selected pipe sewers, well laid and thoroughly flushed -■■■■— - 7 ," Rough iron pipes and ordinary sewer pipes, laid under the usual conditions - v - Tirpsscd masonry and well-laid brickwork vw'-'V \ Good rubble masonry and ordinary rough or fouled brickwork Coarse rubble masonry and firm, compact gravel £v“ canals in“moc 1 era tel y perfbcUy *£ RWeS antPcMials in rather bad condition and somewhat Rivers and canals in bad condition, overgrown with vegeta- tion and strewn with stones and other detritus, according to condition - Value of 7i. .009 .010 .011 .012 .013 .015 .017 .020 .0225 .025 .030 .035 to .050 FLUMES . 145 As it is quite difficult to obtain the value of c by Kutter’s formula, the fol- lowing three approximate formulas for v are given: For canals with earthen banks, If the ditch is lined with dry stonework, 100,000 r 2 s 9 r -f 35 v ; 100, 000 r 2 s * = ■>/ 8r + 16" ,100,000 r 2 s If the ditch is lined with rubble masonry, t» = . y To find the quantity Q of water flowing through any channel in a given time, multiply the velocity by the area, or Q = a v. Flow in Brooks and Rivers.— When a stream is so large that it becomes impracticable to employ a weir for measuring its flow, fairly accurate results may be arrived at by determining the velocity of the current at various points in a carefully surveyed cross-section of the stream, thus determining both v and a. The greatest velocity of current occurs at a point some distance below the surface, in the deepest part of the channel. When determining the current velocities in the different portions of a stream, it is freauentlv advantageous to divide the stream into divisions. Ihis may be accomplished by stretching a wire across and tying strings or rags about the wire at various points. The mean velocity of the current between these points can be determined by current meters, or by floats. The points for observation should be chosen where the channel is comparatively straight and the current uniform. Surface floats may be used, in which case the mean velocity of the point where the float is used may be found as follows: If equals the observed velocity, then the mean velocity will be v = .9 v'. Bv taking observations of the velocity of the current m each section of a stream the amount of water flowing may be determined for each separate section ’ The total amount of water flowing in the stream will be the sum of the amounts in each section. The average velocity of the entire stream mav be found by dividing the total amount of water flowing by total area of the cross-section of the stream. The correction necessary to reduce surface velocity to mean velocity may be made as follows: Measure off x % of the ordinary distance, and figure the time as though for the full distance. For instance, if only 90 ft. were employed, the time would be taken and the problem figured as though it were 100 ft., on account of the fact that the mean velocity is only T % of the surface velocity. FLUMES. Flumes are used for conveying water when a ditch line would be abnormally long, or when the material to be excavated is very hard. They may be constructed of timber or of metal, but metal flumes are compara- tively rare as piping can be used instead. The line of the proposed flume should be carefully cleared of all standing timber, and the brush burned for at least 20 ft. each side of the flume line to prevent danger from fire. The life of an ordinary flume, which is supported on or constructed of timber, is always short, varying, as a rule, from 10 to 20 years, depending on whether the flume is allowed to run dry a portion of the year or is always full of water, the care with which it was originally constructed, and the attention paid to repairs. „ , , , ,, Grade of Flumes.— Flumes are usually set on a much steeper grade than is possible in ditches, the grade frequently being as much as 25 to 30 ft. per mile and in special cases even more. The result of this is that the carrying capacity of flumes is much greater than that of ditches of the same size. The form of flume depends largely on the material of which it is constructed. Metal flumes may have a semicircular form, while wooden flumes are either rectangular or V-shaped. The former is used almost exclusively for con- veying water, and the latter quite extensively for fluming timber or cord wood from the mountains to the shipping point in the valley. Timber flumes should be so constructed that the water will meet with but small resistance, and the bottom and side should be enclosed in a frame of timbers so braced or secured that there is no possible chance of the sides spreading or lifting from the bottom, and thus cause leakage. As a rule, all mortised and tenoned joints should be avoided in flume construction, m mm * « W ■* Thai Inmw -nar liare -hen- hil -ar— tnc ranarit y^ hey ha ve ha <* n -n mlM if i Parser m a wr tiitn u mfh *he -niranr* amt the* f t. In mrt --r»n ntm*» i 31*. ' le iese T» rniunrut "he Inm* 3 aiTna* Aailfiv Imm-i r:Il nnt in *he flrfrr • 'jmrki.jr .it will tp-eze n tnm t*> uvt ates inrii "he-r an? nraearmily a *>t*f*a»‘W When a 'tnnie * awi in hie rrinmt an-ne a T a n k it eu uni «aaf aw vi hu? «*na t» payable. •> a» si imteri it ftnm «wa h = 1.25 D 2 /d7; V = l.G]/ Dh. As a rule, it is best to calculate any pipe line by the formula for pipes having a rough internal surface, for if this is not done the results are liable to be disappointing, since all pipes become more or less rough with use. Eytetwein’s Formula for the Delivery of Water in Pipes: D = diameter of pipe in inches; H = head of water in feet; L = length of pipe in feet; IF = cubic feet of water discharged per minute IF =4.71^^-. D .538 5 L X IF 2 \ II ■ Hawksley’s Formula: G L H D number of gallons delivered per hour: length of pipe in yards; head of water in feet; diameter of pipe in inches. D = 4 “ (15 Df II Neville’s General Formula: v = velocity in feet per second; r = hydraulic mean depth in feet; s = sine of inclination, or total fall divided by total length. v = 140 / r s — 11 / r s. In cylindrical pipes, v multiplied by 47.124 d 2 gives the discharge per minute in cubic feet, or v multiplied by 293.7286 d* gives the discharge per minute in gallons, d being the diameter of the pipe in feet. COMPARISON OF FORMULAS . 149 COMPARISON OF FORMULAS. R = mean hydraulic depth in feet = area -i- wet perimeter = - for circular section of pipe; 4 S = sine of slope = j-; v = velocity in feet per second; d = diameter of pipe in feet; L = length of pipe in feet; H = head of water in feet. Prony, v Eytelwein, Eytelwein, Hawksley, Neville, Darcy, = 97.05]/ RS — .08; or, v = 99.88 \/RS- .154. f dH L + 50 d' v = 108]/.RS-.13. V = + v = U0\/RS — llfr RS. v = C]/ R S; for value of C, see following Table. Diameter of pipe (inches) 1 2 1 2 3 4 5 6 7 8 Value of C. 65 80 93 99 102 103 105 106 107 Diameter of pipe (inches) 9 10 12 14 16 18 20 22 24 Value of C 108 109 109.5 110 110.5 110.7 111 111.5 111.5j Maximum value of C for very large pipes, 113.3. v = C \Zr~s, Kutter, where Weisbach, 181 + .00281 C = .026/ . , .00281 \ l + -7=( 416 + -S ~) y' d'- V 2 ft = ^.0036 + ^V »' V Vv where h = head necessary to overcome the friction in a pipe; r = the mean radius of the pipe in feet; and g = gravity = 32.2. Siphons.— When any part of the pipe line rises above the source of supply, such a line is called a siphon. If this rise is greater than the height of the water barometer (34 ft. at sea level), water will not flow through the siphon. The flow through the siphon will be the same as that through any pipe line so long as there is no accumulation of air at the highest point of the line; but such an accumulation will decrease or entirely stop the flow. All siphons should be provided at their highest points with valves for discharging the air and introducing water to fill the siphon, and it is usually best to trap the lower end of the pipe so that air cannot enter it, and to enlarge the upper end so as to reduce the loss of the stream in entering. For a siphon to work well, the fall between the intake and the discharge end should be considerable, if the rise amounts to much. Table Showing the Actual Amount, or 80$ of the Theoretical Flow in Pipes From $ In. to 30 In. Diameter. ( Supplement to “Industry” No. 45, April, 1892.) 150 HYDRAULICS. 1 o OCHCCC:iOH(NO^OJMCiQ(NCOH(N05COOOOHiOH>ftfiOQ002} Gri«Or;OI>WXC3a5?3cCI>H^lNriKNCOCCNNC0i005C0t'OOOO(N(N^t>I>0>00C0t'O0> 1 CO T^coodcTT^<>ra5^'io' | X)co'crTfC5'co'eoo'co'coo'orio'orc^rric'?crio' ^^ UU HHHHHHH(NlNCOCO'^rl«oco^oo5iOOi(NTt'oooooJ iooci!NN^oioo(MOLCinc ; 3>^i''C:r-Hccioog;QOcoio CD O'- X 1> r" l-' CO O ^ C^CO^iO^I>t^ododoic0^orOOa0 0500 rH rH 1 00 NCOt'HOOt'OiTCcOCO'^OXCOOOX'tCO'^iNKiOHHOO O^TriCH^COHXCOLOXCOCC^COO'JXl-yt-OO^HCr-; CJoocoi'-rHTt-t^oc^ic | cor-iict^aoooi^«C'^ , !N GNl^iNiOiOTfiMCr.L'CTriOOCiCOlX'TOiOXiJit^COO^COCl t'ti'7'i>aiHcoicoxT-ii-ic;t^^oooii^ocoHcoo>oaii>^ r-iHni-i of ofof ofofHp ©~>o © i> ad co of© nr i>^o ^^i^cc o of 1— ii-iM(NiC(Nr-iiN(Nl^LOXOXC'.r-iXOt^^'C'<} , MC:rHi-iO!P ttoc:i>oc^coco(Nt- lOMriccMocoiCLCoa omooiO'^c^ TpOXa'.r^MCO'^cCCCOO^XfNOOKNuOOXvOO'-MCOiOiOiO HHHHHH 040fc0C0^^^iCiOcdoTrH iC l> 00 THHHHnr'H COcONiOCJOt'COXMXOlNHrHMNCiLCN^uCr-^NXO ?^2xxt-'C^^ox^TTXOOCrHO(NTrc:cr-ooxQO o:S^Oi>OC050r-!C^MXCCb-0'!I , CCS(N , ^'!j , 03MCCTt , CO!NOM rHrHr4‘ r H l ^c4‘c4'cOofcOCO^rrOI>Oro^HCicO^'^' m a> A o o 1— 1 05LO000005O'^J , 00i— 1 TT ©C5 HMiCOCI NHftb^ON r-T r-T i-T of of of of co co" co" »q © i< od ad of o' A A 05 (NOXXOOO>rt>'1iHC'OOHTl l X'1'H050COHCWOiO rlr- l05©COCOCOOOCOI>-COi— lrt l lOHt‘OICOCOOCt^aO©lCaOlOGi05I>; C^COCO^ , OiOOCOI>b‘H'^OXO »C C^0Oh1^O5 rHrHrfrHofofofcfofcd^iO©©l>l>adcd CO CO O^^OM'^COOMiOOOM^XXLO^(N'^l>'fl , NWOOiCri iOC0O5HfiO5COt>©~^ , C'-Hj'rf©a0iOCO'^T— rH040ICOCO''tf'^iOiOiOGO©OlCOiO>© t^oqO^cq© r^© rH^q_O5_C0©^ r-T i-T H H H H H H (N M lO" lO' O O Ch £ riOC5ffl(»«LO(NOflO»050H(NiO(NMHHgM05Hb.W03; ssasjssssssssffsasasaqsssssgass rHrHr^rHrHOfofofcdcdcOHjfrf^r <*h o u o o Tf l HOL0[^XO'^ON'fTt , XCCMin' , !fOC5OOHX'^'MOXO r-i r-t r-i r— i MMC^MC^'^iOOOt^t'XCO'.CCt^ONTfOXOM rHrHCfofofofofcdcd o a lO ©osaocoi^ooJcococoTFi^ocorHO^-oicopiacNOSr-^oiiOj-*© ^ WW HrtnHHrtHNCOCO^^iOOLOO«OIN^iOOMC50 <3 rH rH r-T rH rH rH rH of s ©05©00©C0©©04C0^05©t^rrTtfO£^00I>;000C^r;2‘C0050J C^CO'^iOOI>XXC505^i^’-(N'^'qH(NC'.i-iCOi-ii-iqt'qxqqqwi>ri^qqq a i— i CO dcdcoNHOocH^dddH^cdNNdindsCNOOwOojcj ?0OI>TfC0OC0C51>-'^ , C0C0»01>;01iH«qt>iq»q'^P'^C00005 r-({0 C4 ^rH^^OOicOlOrfcicO^COrHC^CO^CO^fHCOOS©;-^©©;^ i-IHHHC' 1C^C^O< Ol lO © i."* £" CO 05 05 © JO 00 rH H}J 05 rH CO lO (NiCfNXT-i^iooociot^oqqqqqqqqqHM-^qHq ^oc»05i^c4coTi?iooTj?otoO'^QOC^00a6oidHHi>i-5iCoQrHHr:®eiT-j«oo»c5oSQes©3 ^ rH rH rH OJ O^ Ol CO CO CO CO ^ © l> CO 05 r^ r-H Ol CO -to OO05O^C5^05Tf05l>I>»q050q^p c4c6coHiCu5cd®^i>:HH^o^gQgg5^Hg^^gggi^ NC'.^ocooocoooMiNXfNiCNXC'.asi-i^xccooNqq £ NocoooooNTfcot-H«H05coeoocOH»^q«qqHrjq rH ’rHrHHHoicScSolcSHiiO^l^OOOJoSg^^^ggjgHgg C*r (MOrt*COCOCOt^Tfoc5ccooo:qqHMMqqqqqq r^ rH rH rH rf of of CO CO h* rt< I> O0 © ^ lO JO JO — «ic* riN(MNnH‘®H'l'COOQOTl'»iH(NCO'tO'}'NHOOHHMCOO iHHM(Ncccoc3'^^'^i>xOricc'^qqMqHi>HqqMNq rJi-^rHrHiHrHridcOCOTtTflOlOLOd e*x> iTXOCO^CDX05H!NK!NOO(NXC0 05CCNCJ9pr.CJr.qcOC2 g§S^SrHrHrHCl>-COOaiOI>00>^iqi>05_ Fall or Slope. 1 in 1,000 2 in 1,000 3 in 1,000 4 in 1,000 5 in 1,000 6 in 1,000 7 in 1,000 Sin 1,000 9 in 1,000 1 in 100 2 in 100 3 in 100 4 in 100 5 in 100 0 in 100 7 in 100 8 in 100 9 in 100 1 in 10 2 in 10 3 in 10 4 in 10 5 in 10 6 in 10 7 in 10 8 in 10 9 in 10 10 in 10 The quantities above are American gallons per minute. For cubic feet, divide by 7.5. FRICTION IN PIPES. 151 LOSS OF HEAD IN PIPE BY FRICTION In each 100 ft. in length of different diameters, when discharging the follow- ing quantities of water per minute, as given by Pel ton Water Wheel Co. Inside Diameter of Pipe. Inches. Velocity. Ft. per Sec. 1 2 3 4 5 6 Loss of Head. Ft. Cu. Ft. per Min. Loss of Head. Ft. Cu.' Ft. per Min. Loss of Head. Ft. Cu. Ft. per Min. Loss of Head. Ft. Cu. Ft. per Min. Loss of Head. Ft. ! Cu. Ft. per Min. Loss of Head. Ft. | 1 Cu. Ft. per Min. 2.0 2.37 .65 1.185 2.62 .791 5.89 .593 10.4 .474 16.3 .395 23.5 2.2 2.80 .73 1.404 2.88 .936 6.48 .702 11.5 .561 18.0 .468 25.9 2.4 3.27 .79 1.639 3.14 1.093 7.07 .819 12.5 .650 19.6 .547 28.2 2.6 3.78 .86 1.891 3.40 1.260 7.65 .945 13.6 .757 21.3 .631 30.6 2.8 4.32 .92 2.160 3.66 1.440 8.24 1.080 14.6 .864 22.9 .720 32.9 3.0 4.89 .99 2.440 3.92 1.620 8.83 1.220 15.7 .978 24.5 .815 35.3 3.2 5.47 1.06 2.730 4.18 1.820 9.42 1.370 16.7 1.098 26.2 .915 37.7 3.4 6.09 1.12 3.050 4.45 2.040 10.00 1.520 17.8 1.220 27.8 1.021 40.0 3.6 6.76 1.19 3.380 4.71 2.260 10.60 1.690 18.8 1.350 29.4 1.131 42.4 3.8 7.48 1.26 3.740 4.97 2.490 11.20 1.870 19.9 1.490 31.0 1.250 44.7 4.0 8.20 1.32 4.100 5.23 2.730 11.80 2.050 20.9 1.640 32.7 1.370 47.1 4.2 8.97 1.39 4.490 5.49 2.980 12.30 2.240 22.0 1.790 34.3 1.490 49.5 4.4 9.77 1.45 4.890 5.76 3.250 12.90 2.430 23.0 1.950 36.0 1.620 51.8 4.6 10.60 1.52 5.300 6.02 3.530 13.50 2.640 24.0 2.110 37.6 1.760 54.1 4.8 11.45 1.58 5.720 6.28 3.810 14.10 2.850 25.1 2.270 39.2 1.900 56.5 5.0 12.33 1.65 6.170 6.54 4.110 14.70 3.080 26.2 2.460 40.9 2.050 58.9 5.2 13.24 1.72 6.620 6.80 4.410 15.30 3.310 27.2 2.650 42.5 2.210 61.2 5.4 14.20 1.78 7.100 7.06 4.730 15.90 3.550 28.2 2.840 44.2 2.370 63.6 5.6 15.16 1.85 7.580 7.32 5.060 16.50 3.790 29.3 3.030 45.8 2.530 65.9 5.8 16.17 1.91 8.090 7.58 5.400 17.10 4.040 30.3 3.240 47.4 2.700 68.3 6.0 17.23 1.98 8.610 7.85 5.740 17.70 4.310 31.4 3.450 49.1 2.870 70.7 7.0 22.89 2.31 11.450 9.16 7.620 20.60 5.720 36.6 4.570 57.2 3.810 82.4 Inside Diameter of Pipe. Inches. . o 7 8 9 10 11 12 Velocity Ft. per S< Loss of Head. Ft. Cu. Ft. per Min. Loss of Head. Ft. Cu. Ft. per Min. Loss of Head. Ft. Cu. Ft. per Min. Loss of Head. Ft. -w S3 *3 * Loss of Head. Ft. Cu. Ft. per Min. Loss of Head. Ft. Cu. Ft. per Min. 2.0 .338 32.0 .296 41.9 .264 53.0 .237 65.4 .216 79.2 .198 g 94.2 2.2 .401 35.3 .351 46.1 .312 58.3 .281 72.0 .255 87.1 .234 103.0 2.4 .468 38.5 .410 50.2 .365 63.6 .327 78.5 .297 95.0 .273 113.0 2.6 .540 41.7 .473 54.4 .420 68.9 .378 85.1 .344 103.0 .315 122.0 2.8 .617 44.9 .540 58.6 .480 74.2 .432 91.6 .392 111.0 .360 132.0 3.0 .698 48.1 .611 62.8 .544 79.5 .488 98.2 444 119.0 .407 141.0 3.2 .785 f 1.3 .686 67.0 .609 84.8 .549 105.0 .499 127.0 .457 151.0 3.4 .875 54.5 .765 71.2 .680 90.1 .612 111.0 .557 134.0 .510 160.0 3.6 .969 57.7 .848 75.4 .755 95.4 .679 118.0 .617 142.0 .566 169.0 3.8 1.070 60.9 .936 79.6 .831 101.0 .749 124.0 .680 150.0 .624 179.0 4.0 1.175 64.1 1.027 83.7 .913 106.0 .822 131.0 .747 158.0 .685 188.0 4.2 1.280 67.3 1.122 87.9 .998 111.0 .897 137.0 .816 166.0 .749 198.0 4.4 1.390 70.5 1.220 92.1 1.086 116.0 .977 144.0 .888 174.0 .815 207.0 4.6 1.510 73.7 1.320 96.3 1.177 122.0 1.059 150.0 .963 182.0 .883 217.0 4.8 1.630 76.9 1.430 100.0 1.270 127.0 1.145 157.0 1.040 190.0 .954 226.0 5.0 1.760 80.2 1.540 105.0 1.370 132.0 1.230 163.0 1.122 198.0 1.028 235.0 5.2 1.890 83.3 1.650 109.0 1.470 138.0 1.320 170.0 1.200 206.0 1.104 245.0 5.4 2.030 86.6 1.770 113.0 1.570 143.0 1.410 177.0 1.280 214.0 1.183 254.0 5.6 2.170 89.8 1.890 117.0 1.680 148.0 1.510 183.0 1.370 222.0 1.260 264.0 5.8 2.310 93.0 2.010 121.0 1.800 154.0 1.610 190.0 1.460 229.0 1.340 273.0 6.0 2.460 96.2 2.150 125.0 1.920 159.0 1.710 196.0 1.560 237.0 1.430 283.0 7.0 3.260 112.0 2.850 146.0 2.520 185.0 2.280 229.0 2.070 277.0 1.910 330.0 Example. — Have 200 ft. head and 600 ft. of 11" pipe, carrying 119 cu. ft. of water per minute. To find effective head: In right-hand column, under 11" pipe, find 119 cu. ft. Opposite this will be found the coefficient of friction for this amount of water, which is .444. Multiply this by the number of hun- dred feet of pipe, which is 6, and you will have 2.66 ft., which is the loss of head. Therefore, the effective head is 200 — 2,66 = 197,34. 152 HYDRA ULICS. LOSS OF HEAD IN PIPE BY FRICTION Tn each 100 ft in length of different diameters, when discharging the follow- ing quaXies of water per minute, as given by Pelton Water Wheel Co. Inside Diameter of Pipe. Inches. % a 13 14 15 16 18 20 Loss of Head. Ft. Cu. Ft. per Min. Loss of Head. Ft. Cu. Ft. per Min. Loss of Head. Ft. Cu. Ft. | per Min. Loss of Head. Ft. Cu. Ft. per Min. Loss of Head. Ft. £.5 3 t- O (4r2 + 5F_2 ), where/ 1 = friction head; L = length of pipe in feet; D = diameter of pipe in inches; V = velocity in feet per second. Friction of Knees and Bends. -This subject has not been investirated suffi- ciently to enable the- engineer to make exact allowance for this factor, but the following formulas may be taken as giving close approximate results. It is well to bear in mind that right angles should be avoided whenever possible, and that bends should be made with as large a radius as circum- A = angle of bend or knee with forward line of direction; V = velocity of water in feet per second; R == radius of center line of bend; r = radius of bore of pipe (or i diameter); K = coefficient for angles of knees; L = coefficient for curvature of bends; H = head of water in feet necessary to over- come the friction of the bends, or knees. H = .0155 V 2 K. The value of iTis as follows for different angles: 20° 40° 60° I 80° 90° 100° 120° .046 .139 .364 1 ' 74 1 .98 1.26 1.86 stances will allow. For bends, H = .0155 V 2 (Ai). 154 HYDRA ULICS. Values of L with various ratios of the radius of bend to radius of bore: When = j .1 ' .2 ! .3 •4 | 1 .5 .6 j • 4 .8 | .9 i 1 1.0 In circular section L .131 ! .138 .158 . '206 ! .294 .44 .66 .98 1.4 2.0 In rectangular L .124 ; .135 .18 .25 .4 .64 1.01 1.55 , 2.3 | 3.2 RESERVOIRS. Reservoir Site.— In selecting a site for a reservoir, the following points should be observed: 1 . A proper elevation above the point at which the water is required. 2. The total supply available, including observations as to the rainfall and snowfall. 3. The formation and character of the ground, with reference to the amount of absorption and evaporation. The most desirable formation of ground for a reservoir site is one of com- pact rock, like granite, gneiss, or slate; porous rocks, like sandstones and limestones, are not so desirable. Steep bare slopes are best for the country surrounding a reservoir, as the water escapes from them quickly. The presence of vegetation above the reservoir causes a considerable amount of absorption; but, at the same time, the rainfall is usually greater in a region covered with vegetation than in a barren region, hence the streams have a more uniform flow. A reservoir must be made large enough to hold a supplv capable of meeting the maximum demand. The area of a reservoir should be determined, and a table made showing its contents for every foot in depth, so that the amount of water available can always be known. DAMS. Dams are used for retaining water in reservoirs, for diverting streams in placer mining, and for storing debris coming from placer mines in canons or ravines. Foundations for dams must be solid to prevent settling, and water-tight to prevent leakage under the base of the dam. Whenever possible, the founda- tion should be solid rock. Gravel is better than earth, but when gravel is emploved it will be necessary to drive sheet piling under the upper toe of the dam, to prevent water from seeping through the formation under the dam. Vegetable soil should be avoided, and all porous material, such as «and, gravel, etc. should be stripped off until hard pan or solid rock is reached. In case springs occur in the area covered by the foundation of the dam, it will be necessary to trace them up, and if they originate on the upper side to confine their flow to that side of the dam. so that they will have no tendency to ultimately become passageways for water from the upper face to the lower face of the dam, thus providing holes which may ultimatelv destrov the entire foundation of the structure. Wooden Dams.— Wooden dams are constructed of round, sawed, or hewn logs. The timbers are usually at least 1 ft. square, or, if round, from 18 to ^4 in in diameter. A series of cribs from 8 to 10 ft. square are constructed by building up the logs log-house fashion and securing them together with treenails. The individual cribs are secured to one another with treenails or by means of bolts. The cribs are usually filled with loose rock to keep them in place, and in many cases are secured to the foundation by means of bolts A laver of planking on the upper face of the dam makes it water- tight. and if the spillway is over the crest of the dam it will be necessary to plank the top of the cribs, and. in most cases, to provide an apron for the water to fall on. The apron may be set on small cribs, or on timbers pro- ‘ecting from the cribs of the dam itself. J Abutments and Discharge Gates.— Abutments are structures at the ends of a dam They mav be constructed from timber, masonry, or dry stonework. If possible' abutments should have a curved outline, and should be so placed that there is no possibility of the water overflowing them, or getting behind them during floods. If the regular discharge from a dam takes place from the main face, the gates may be arranged in connection with one of the abutments, or by means of a tunnel and culvert through the dam. In DAMS. 155 either case, some structure should he constructed above the outlet so as to prevent driftwood, brush, and other material from stopping the discharge gates. When the discharge gates are placed at one side o£ the dam, they are usually arranged outside of the regular abutment, between it and another special abutment, the discharge being through a series of gates into a flume, dlt Spillways P or Waste Ways— These are openings provided in a dam for the discharge of water during floods or freshets, or tor the dischargeofaportioii not being used at any time. The spillway may be over the crest of the dam, or where the topography favors such a construction, the mam dam may be of’ sufficient height to prevent water from ever passing its crest, the spillway being arranged at another outlet over the lower dam. Waste ways, proper, are openings through the dam, and are intended for the discharge of the large quantities of water that come down during freshets or floods. In the case of timber dams, the waste ways are usually surrounded by heavy cribs, and have an area of from 40 to 50 sq. ft. each. There are two general forms of construction employed for waste ways. One consists of a compara- tively narrow opening in the dam, extending to a considerable depth (8 or Fig. 18. 10 ft ) Water is allowed to discharge through this during flood time, but when it is desired to stop, the flow planks are placed across the up-stream face of the opening in such a manner as to close it. The opening, which is usually not over 8 or 4 ft. wide, is provided with guides on the upper face of the dam, and between which the planks are slid down, the individual pieces of planking being at least 1 ft. longer than the opening that they are to cover. The other device frequently used consists m providing the waste way at one side of the regular spillway, with a crest 2 or 3 ft. lower than the rejmlar spillway. The and 4 or spillway. 5 ft. abc . e VVove there is arranged a parallel timber, the space between ’ ■ ” flash boards. These are made from the two being closed by what are called uasn ^ — ~rr nieces of 2" or 3" plank, 6 or 8 in. wide. The planks are placed against both timbers so as to close the space. The individual p anks are made long enough so that they extend from 1 to 2 ft. above the upper timber, and through the upper end of each plank is bored a hole through which a piece of rope is passed and a knot tied in the end of the rope. These ropes are secured by staples to the upper timber. When it becomes necessary to open the waste way, men go under with peevies, cant hooks, or pmch bars, and pry up the planks in such a way as to draw the longer end out of contact with the lower timber, when the force of the water will immediately carry the plank down the stream as far as the rope will allow it to go. After the first plank has been loosened, the succeeding ones can be pulled up with comparative ease, and two men can open a 25' or 30 section of waste way in a very few minutes. The ropes keep the plank from being lost, and the opening can be closed again by passing the plank down into the water to one side of the opening and moving them into the current. Some skill is required, both in opening and closing the waste ways. Stone Dams— Where cement or lime is expensive and suitable rubble stone can be obtained, dams are frequently constructed without the use of mortar. The upper and lower faces of the dam should be of hammer- dressed stone, carefully bonded, and the stones m the lower face of the dam are sometimes anchored by means of bolts. The dam can be made^ter- tight by means of a skin of planking on the upper face. In case water should ever pass over the crest of such a dam, much of it would settle through the openings in the stone into the interior of the dam, and this would subject the stones in the lower portion of the face to a hydrostatic 156 HYDRAULICS. pressure, provided an opening was not made for the escape of such water. For this reason, culverts or openings should be made through the lower portion of the dam, to discharge any such water. When such dams as this are constructed, the regular spillway is not placed over the face of the dam, but at some other point, and usually over a timber dam. Earth Dams.— Earth dams are used for reservoirs of moderate height. They should be at least 10 ft. wide on top, and a height of more than 60 ft. is unusual When the material of which the dam is composed is not water- tight as for instance, gravel, sand, etc., it is sometimes necessary to con- struct a puddle wall of clav in the center of the regular dam. This consists of a narrow dam of clay mixed with a certain proportion of sand. The nuddle wall should not be less than from 6 to 8 ft. thick at the top of the dam and should be given a slight batter on each side. It is constructed during the building of the dam, and should be protected from contact with the water bv a considerable thickness of earth on the upper face. The unner face of an earthen dam is frequently protected by means of plank or a pavement of stone. The lower face is frequently protected by means of cod or sod and willow trees. Sometimes earth dams are provided with a masonrv core in place of the puddle wall, to render them water-tight. This consists of a masonrv wall carried to an impervious stratum, and up through the center of the dam. The masonry core should never be less than 2 or 3 ft. thick at the top, and should be given a batter of at least 104 on each side. At the regular water level, earthen dams are liable to have a small bench or shelf formed, and on this account, during the construction, such a bench or shelf is sometimes built into the earth dam. Fig. 18 shows a dam with a masonry core, with the upper face covered with rubble and the lower face covered with grass. . , , , Debris Dams —These are dams or obstructions placed across the bed of streams to hol’d back tailings from mines, and to prevent damage to the vallevs below. They are made of stone, timber, or brush. No attempt is made to render the debris dam water-tight, the only object being that it should retard the flow of the stream and give it a greater breadth of dis- charge co that the water naturally drops and deposits the sediment that- it is carrying The sediment soon silts or fills up against the face of the dam the ‘area above the dam becoming a flat expanse or plain over which the water finds its way to the dam. When these darns are constructed of stone the individual stones on the lower face and crest of the dam should be so laro-e that the current will be unable to displace them, while the upper face and core of the dam mav be composed of finer material. In case a breach should occur in the debris dam, it will not necessarily endanger the region farther down the stream, as is the case when a break occurs m a water dam The reason for this is that the debris dam is not made water- tight and hence there is never much pressure against it, or a large volume of water held back that can rush suddenly down the stream should a break occur The only result of the break would be that more or less of the gravel behind the dam* would be washed through the breach. wing Dams —Wing dams are used for turning streams from their courses, so as to expose all or a portion of the bed for placer mining or other pur- poses They are usually of a temporary nature, and are constructed of brush and stones, light cribs filled with stones, and of large stones or timber Sometimes the course of a stream is turned by an obstruction inade of sand bao-s and a wing dam constructed behind this of frames of timoer, the inter- vening space being filled with gravel or earth, and. in some cases, the timber being covered with stone, and the surface nprapped so that if the flow ever comes over the top of the structure it will not destroy it. Masonrv Dams —When high masonry dams are to be employed they should be designed bv a competent hydraulic engineer. Masonry dams are not, as a rule used for hydraulic mining, owing to the fact that the length of time during which the dam is required rarely warrants the expense ot the con- struction of a masonry dam. WATER-POWER. The Theoretical Efficiency of the Water-Power.-The gross power of a fall of water is the product of the weight of water discharged in a unit of time, and the total head or difference in elevation of the surface of the water, above and below the fall. The term head, used in connection with waterwheels, WATER-POWER. 157 is the difference in height between the surface of water in the penstock and that in the tailrace, when the wheel is running. If q = cubic feet of water discharged per minute, W = weight of a cubic foot of water = 62.5 lb., and H = total head in feet, then WQH = gross power in foot-pounds per minute, and = the horsepower. Substituting the value for W, we have = .00189 Q H. as the horsepower of a fall. 83 000 The total power can never be utilized by any form of motor, owing to the fact that there is a loss of head, both at the entrance to, and exit from, the wheel, and there are also losses of energy, due to friction of the -water m passing through the wheel. The ratio of the power developed by the wheel to the gross power of the fall, is the efficiency of the wheel. A head of water can be made use of in any one of the following ways: 1 By its weight, as in the water balance, or overshot wheel. i. By its pressure, as in the hydraulic engine, hydraulic presses, cranes, etc., or in a turbine water wheel. , , , . . , , , 3. By its impulse, as in the undershot and impulse wheels, such as Peltons, etc. 4. By a combination of the above. The Horsepower of a Running Stream.— The gross horsepower, as seen above, is H. P. = — .00189 Q if, 33,000 . ... in which Q is the quantity in cubic feet per minute actually impinging on the float or bucket, and if the theoretical head added to the velocity of the stream, or H 2 g 64.4’ in which v is the velocity in feet per second. , For example, if the floats of an undershot waterwheel were 2 ft. X 10 ft. .and the stream had a velocity of 3 ft. per second, i. e., v = 3, we would have H = = .139, and Q = 2 x 10 X 3 x 60 = 3,600 cu. ft. per min. From this, H. P. = 3,600 X .139 X .00189 = .945 H. P., or a gross horse- power for practically .05 sq. ft. of wheel surface; but, under ordinary circum- stances, it would be impossible to attain more than 40^ of this, or practically .02 horsepower per sq. ft. of surface, which would require 50 sq. ft. of float surface to each horsepower furnished. Current Motors.— A current motor fully utilizes the energy of a stream only when it is so arranged that it can take all of the velocity out of the water; that is, when the water leaves the floats or vanes with no velocity. It is evident that in practice we can never even obtain a close approximation to these results, and hence only a small fraction of the energy of a running stream can be utilized by the current motor. Current motors are frequently used to obtain small amounts of power from a large stream, as, for instance, for pumping a limited amount of water for irrigation. For this work, an ordinary undershot wheel having radial paddles is usually employed. At one end of the wheel a series of small buckets are placed, and so arranged that each bucket will dip up water at the bottom of the wheel and discharge it into the launder, near the top of the wheel. The shape of the buckets should be such that only the amount of water which the bucket is capable of carrying to the launder will be dipped up, for if the bucket is constantly slopping or pouring water as it ascends, a large amount of useless work is performed in raising this extra water and then pouring it out again, as only the portion that reaches the launder can be of any service. Current motors are not practicable for furnishing large amounts of power. UTILIZING THE POWER OF A WATERFALL. The power of a waterfall may be utilized by a number of different styles of motors, but each has certain advantages. Breast and Undershot Wheels.— When the head is low (not over 5 or 6 ft ), breast or undershot wheels are frequently employed. If these are properly 158 HYDRAULICS . proportioned, it is possible to realize from 25# to 50# of the theoretical power of the fall, but the wheels are large and cumbersome compared with the duty they perform, and not often installed at present, especially near manufac- | turing centers. „ , A , . Overshot Wheels.— For falls up to 40 or 50 ft., overshot wheels are very commonly employed, and they have been used for even greater heads than this. The overshot wheel derives its power both from the impulse of the water entering the buckets, and from the weight of the water as it descends on one side of the wheel in the buckets. The latter factor is by far the, more important of the two. When properly proportioned, overshot wheels may realize from 70# to 90# of the power of the waterfall, but they are large and cumbersome compared with the power that they give, and are not often installed except in isolated regions, where they are made from timber by local mechanics. „ . Impulse Wheels.— For heads varying from 60 ft. up, impulse wheels are very largely used. These are also sometimes called hurdy gurdies, and are usually of the Felton type, consisting of a wheel provided with buckets, so arranged about its periphery that they receive an impinging jet of water and turn it back upon itself, discharging it with practically no velocity, and con- verting practically all the energy into useful work. The efficiency of these wheels varies from 85# to 90# under favorable circumstances. This style of wheel is especially adapted for very high heads and comparatively ^small amounts of water. There are a number of instances where wheels are operating under a head of as much as 2,000 ft. This style of impulse wheel i is an American development; in Europe, a style of impulse turbine has been li used to some extent, but has not found very much favor in the United States. Turbines.— Turbines or reaction wheels are very largely employed, espe- cially for moderate heads. When properly designed to fit the working conditions, they can be used for heads varying from 4 or 5 ft. up to consider- ably over 100 ft., and when properly placed are capable of utilizing the entire head, a factor that gives them a decided advantage over any other style of waterwheel. Turbines are capable of returning 85# to 90# of the theoretical energy as useful power, and are largely used, especially where a considerable volume of water at a low head, or a smaller volume at a moderate head, can be obtained. PUMP MACHINERY. Pumps are employed for unwatering mines, handling water at placer mines, irrigation, water-supply systems, boiler feeds, etc. For un watering mines, two general systems of pumping are employed. (1) The pump is placed in the mine and is operated by a motor on the sur- face, the power being transmitted through a line of, moving rods. (2) Both the motor and pump are placed in the mine, the motor being an engine driven by steam, compressed air, hydraulic motor, or an electric motor. Cornish Pumps.— Any method of operating pumps by rods is commonly called a Cornish system. Formerly, the motor in the Cornish system con- sisted of a steam engine placed over the shaft head, which operated the pump by a direct line of rods. With this arrangement, there is great danger of accident to the engine from the settling of the ground around the shaft, or from fire in the shaft; also, the position of the motor renders access to the shaft difficult. To overcome these objections, the engine is frequently placed at one side of the shaft, and the rods operated by a bob; this has become the common practice, and is generally called the Cornish rig. The engine employed in the most modern plants is generally of the Corliss type, and is provided with a governor to guard against the possibility of the engine running away, in case the rods should break. This svstem requires no steam line down the shaft, and is independent of the depth of water .in the mine, so that the pump is not stopped by the drowning of a mine, but the moving rods are a great inconvenience in the shaft, and they absorb a great amount of power by friction. Simple and Duplex Pumps.— In the simple pump, a steam cylinder is con- nected directly to a water cylinder, and the steam valves are operated by tappets. Such a pump is more or less dependent on inertia at certain points of the stroke to insure the motion of the valves, hence will not start from P VMP M A C MINER Y. 159 anyplace, but is liable to become stalled at times. In the duplex pump, two steam cylinders and two water cylinders are arranged side by side, and the valves so placed that when one piston is at mid-stroke it throws the steam valve for the other cylinder, etc. With this arrangement, the pump will start from anv point, and can never be stalled tor lack of steam, due to the position of the valves. Ordinarily, duplex pumps are to be pre- ferred for mine work. , ... , . , The packing for the water piston of a pump maybe either inside or outside. Any form of packing that is inside the cylinder, either upon a moving piston or surrounding the ram, and so situated that any wear will allow communi- cation between the oppo- site ends of the cylinder, is called inside packing. It may consist simply of piston rings about the pis- ton, as in the case of an ordinary steam-engine pis- ton G, Fig. 19, or stationary rings may be employed about the outside of a mov- Fig. 19. In^either case, the cylinder heads have to be removed before the condition of the packing can be inspected, and any leak does not make itself visible. When outside packing is employed, separate rams are used in opposite ends of the cylinder, there being no internal communication between the chambers in which the rams work. The rams are packed by ordinary outside stuffingboxes and glands. The arrangement consists practically ot two single-acting pumps arranged to work alternately, so that one is forcing water while the other is drawing water. Fig. 20 shows a horizontal section of a cylinder so arranged, together with the yoke rods that operate the ram at the farther end of the cylinder. . , , . . , As a rule, inside-packed pumps should be avoided m mines, on account of the fact that acid or gritty waters are liable to cut the packing, and make the pumps leak in a very short time. For dipping work m single stopes or entries, small single or duplex outside-packed pumps may be employed. It is generally best to operate such pumps by compressed air, for the exhaust will then be beneficial to the mine air. If steam is employed, it is frequently necessary to introduce a trap and remove entrailed water from the steam before it enters the pump, and to dispose of the exhaust by piping it out or condensing it. Such isolated steam pumps are about the most waste! ul form of steam-driven motor in existence. For sinking, center-packed single or duplex pumps are usually employed, the duplex style being the better. For station work, where much water is to be handled, large compound, or triple-expansion, condensing, duplex pump- ing engines are employed. They may, or may not, be provided with cranks and a flywheel. Engineers differ greatly upon this point, and, as a rule, for very high lifts and great pressures, the flywheel is employed. The main points in consideration are the first cost of the pump, and the amount that will be saved by using the more expensive engine. The large flywheel pumping engines are several times as expensive as the direct- acting steam pumps, and the question is as to whether their greater efficiency 6 * * > ^ will more than coun- terbalance the in- creased outlay. Most engineers favor fly- wheel pumps for handling large vol- umes of water where the work is approxi- mately constant, and direct-acting pumps, without fly wheels or cranks, for handling small amounts of water, or for very irregular service, owing to the fact that if the flywheel pump is driven below its normal speed it does not govern properly, nor work economically. Until recently, water was removed from mines in lifts of about 300 to 350 ft., pumps being placed at stations along the shaft. While a series of station pumps are still employed, m some cases they are Fig. 20. 160 PUMP MACHINERY. generallv intended to take care of water coming into the shaft, or workings at or near their level, and are not employed for handling water in successive stages or lifts. For handling the bulk of the water from the bottom of the shaft large pumping engines are employed that frequently force the water to the surface from depths of over 1,000 ft. These high-dutv pumping plants, when near the shaft and operated by steam with a condenser, frequently show a verv high efficienev. When air is employed to operate such a plant a much higher efficienev can be obtained if the compressed air is heated before using in the high-pressure cylinder, and during its passage from the high-pressure to the low-pressure cylinder. This has been very successfully accomplished bv means of a steam reheater, the small amount of steam necessarv being ‘conveyed to the station in the small pipe, and entirely con- densed in the reheater* from which it is trapped as water. . The dutv of steam pumps is approximately as follows: For small-sized steam pumps, the steam consumption is from 180 to 200 lb. per horsepower uer hour when operating in the workings of a mine at some distance from the boiler. For larger sizes of simple steam pumps, the consumption runs from SO to 130 lb. of steam per horsepower per hour. Compound-condensing numps, such as are commonly used as station pumps, consume from 40 to 70 lb. of steam per horsepower per hour. Tnple-expansion. condensing, hi°h-class pumping engines consume from 24 to 26 lb. per hoi^epowerper hemr The Cornish pump consumes varied amounts of steam in proportion to the water delivered, depending largely on the friction of the geanng bobs, rods, etc., but its efficiency is usually considerably below the best class 0f CTo n f wTtfr 1 Through Valves, Pipes end Pump through the valves and passages of a pump should not exceed ^A) ft. per minute and care should be taken to see that the passages are not too abruntlV deflected. The flow of water through the discharge pipe should not exceed 500 ft per minute, but for single-cylindered pumps it is usually figured Id between 250 and 400 ft. per minute. In the case of very large SSS ^reafer velocities maybe allowed. The suction pipe for the pump Should be larger than the discharge pipe. Ordinarily, the suction pipe for a D^ns^uld not exceed 250 ft. in length, and should not contain more than two elbows. The following formula gives the diameter of the suction and discharge pipes of a pump: G = U. S. gallons per minute; _ d' = diameter of suction pipe in inches: d"= diameter of discharge pipe in inches; I G d' = -4.95^^; <*"= 495 \'-^- . . . = velocity of water in feet per minute in the suction pipe - from 50 v" to 75 v" = velocity of water in feet per minute in the discharge pipe. RATIO OF STEAM AND WATER CYLINDERS IN A DIRECT-ACTING PUMP. A = area of steam cylinder; D = diameter of steam cylinder: P = steam pressure in pounds per p = pressure per’ square inch, corresponding to the head H ** ^ wnrk done in nump cylinder H = head of water = 2.309 p; a = area of pump cylinder; d = diameter of pump cylinder; .433 H\ E = A = a = pressure per squar. efficiency of pump — work done in steam cylinder ap D = d EP ’ EAP . P I P . D P = P = iE P M~V' op. EA’ EAP . a JL_ EP .433 H EP ’ H= 2.309 E P X — CAPACITY AND HORSEPOWER OF PUMPS. 161 If E = 75 $, then H = 1.732 PX^. E is commonly taken at from .7 to .8 for ordinary direct-acting pumps. For the highest class of pumping engines it may amount to .9. The steam pressure P is the mean effective pressure, according to the indicator dia- gram; the pressure p is the mean total pressure acting on the pump plunger or piston, including the suction, as would be shown by the indicator dia- gram of the water cylinder. The pressure on the pump cylinder is frequently much greater than that due to the height of the lift, on account of the friction in the valves and passages, which increases rapidly with the velocity of the flow. . . Piston Speed of Pumps.— For small pumps, it is customary to assume a speed of 100 ft. per minute, but, in the case of very small short-stroke pumps, this is too high, owing to the fact that the rapid reverses make the flow through the valves and change in the direction of the current too frequent. When the stroke of the pump is somewhat longer (18 in. or more), higher speeds can be employed, and in the case of large pumping engines having long strokes, speeds of as much as 200 to 250 ft. per minute are successfully used without jar or hammer. Boiler Feed-Pumps.— In practice, it has been shown that a piston speed greater than 100 ft. per minute results in excessive wear and tear on a boiler feed-pump, especially when the water is warm. This is due to the fact that vapor forms in the' cvlinders t and results in a water hammer. In determining the proper size of a pump for feeding a steam boiler, not only the steam employed in running the engine, but that necessary for the pumps, heating system, etc. must be taken into consideration. THEORETICAL CAPACITY OF PUMPS AND THE HORSEPOWER REQUIRED TO RAISE WATER. Q G G> d l N v W P £ Let Q = cubic feet of water per minute; = U. S. gallons per minute; = U. S. gallons per hour; = diameter of cylinder in inches; = stroke of piston in inches; = number single strokes per minute; = speed of piston in feet per minute; == weight moved in pounds per minute; = pressure in pounds per square feet = 62.5 X H; = pressure in pounds per square inch = .433 X H • = height of lift in feet; H. P. = horsepower. Then, Q = \ ■ ^ ~ = .0004545 Nd- 1. O = "■ = .0034 Nd- 1. G> = .204 Nd"- 1. The diameter of piston required for a given capacity per minute will be d = 46 - 9 Vj n = 17 ' 15 \fe ord - 13 - 54 V* = 4 - 95 Vf- The actual capacity of a pump will vary from 60$ to 95$ of the theoretical capacity, depending on the tightness of the piston, valves, suction pipe, etc. QP QHX 144 X .433 = QH = Gp 33,000 33,000 529.2 1,714.5* The actual horsepower required will be considerably greater than the theoretical, on account of the friction in the pump; hence, at least 20$ should be added to the power for friction and usually about 50$ more is added to cover leaks, etc., so that the actual horsepower required by the pump is about 70$ more than the theoretical. Example 1.— If it is desired to find the size of a pump that will throw 30 gal. of water per minute up 125 ft., from the bottom of a pit or prospect shaft to the station pump at the main shaft, it may be accomplished as follows: An allowance of probably 25$ should be made with a small pump of this character, to overcome slippage or leaking through the valves, past the piston, 162 PUMP MACHINERY. etc and hence we will call the total amount of water to he handled 40 gal ner mfnute? The formula for the diameter of piston is F G d = 4.95 yj-. Assuming that v = 100 ft. per minute, we have d = 4.95]/ .4 = 4.95 X .63 = 3.13. Tn -nractice a 31" pump would probably be employed. Fx?mple 2 -If it is desired to find the approximate horsepower necessary to THtwSl /per minute in the above example, without determimng the size of the pump, it can be done as follows: w p __ Q X P = 30 X -433 X 125 __ ^ or prac ti C ally 1 H. P. H,P, ~ 1,714.5 1,714-5 Tn order to cover leakage through valves, friction, etc., an addition of at leas? ^^should°be r nmde to a very" small pump like this, and so we would co “ Auction —Theoretically, a perfect pump will raise water to a , Pepth f f ^bucnon ^ sea level; but, owing to the fact that a perfect ti^Son it is never 'possible to reach this theoretical limit, and, in practice, wlfe^tKter il°coW W Wa“ ter wlter“ pn£F£ir« e o d r ai with a clack valve in the plunger, the amount lifted may actually exceed more water through the valve than would pass through it on account of the ^ce passed through This increases as the speed or number of strokes inc |“ v»lves.-As a rule, a large number of small valveshaving a compar- ativelvsmall opening are preferable to a small number of large valves with a Jreatironening and most modern pumps are built upon these lines. A small valve P represents a proportionately larger surface of discharge with the same lift than the large valve, hence whatever the total area o[ the \ah e onening its full contents can be discharged with less lilt througn numerous s&all valves than through one large valve. Cornish pumps gel power' V Pumps —Where comparatively small amounts of water are to be handfed, and P power is available, belt-driven power pumps are very much "‘'Eleohic^y DHven^e^P^s^bere water is to be delivered from isolated wordings to the sumps for the large station pumps, electrically driven power pumps are far more efficient than steam pumps. In some cases It Fs°mobSy best to equip the entire mine with electnc pumps both ?n the isolated workings and at the stations, on account of the fact that they can^e^rivenl^ 0 ^ high-class compound-condensing ^n^^e °n the ^irface, directly connected to a generator, and furnishing electricity through con- ^ U The S f^al 1 efflciency?f I a^series of small, electric pumps that aggregate a sufficient amount of power to enable this arrangement to be used, is very sufficient amount y e fficiencv of a number of small isolated steam or ra^uresfe^-ai^ wmps^Sroduced C lnto a the workings. With compound- condensing engines upon the surface, operating electric pumps underground ?he st^amconsumption per pump horsepower per hour for the smaller 2“ e would onlvbe about 40 lb. per horsepower per hour; for medium-sized electric° pump?, about 30 lb. of steam per hour, and larger sizes from 20 to 30 lb. per horsepower per hour. It will be seen from these figures that for PUMP AND WATER MEMORANDA, 163 pumping from isolated portions of the mine the electric pump is much more efficient than the steam pump, and owing to the fact that the current can frequently be obtained from the lines operating the underground haulage system, furnishing light, etc., it is evident that this system of pumping has a great future before it in connection with mining. The following table gives the gallons per minute delivered from various sized pumps operating at different piston speeds: Pump and Water Memoranda. Gallons per Minute Delivered at Indicated Piston Speeds. 500 ^occooooooooqoooqqqqqqqqooqooqooqooq dHcodd^ddxw^ddddcccocooocooQOOOOoqto^dqqqoq (NOOXOHCOGCOCMH t> 00 rH 400 coM,ooooooqqqqqqqqqqqqqqqqqqqqqqqqqqq cotdi>rHodo6ooo6^<^cM'eocM‘aiioodooo6TjHoirHCMOco^co^oo^cM3oqo H(O^COOOOOOH^t-(NI>COONiOiOiOiOt-OM^CMt-^HOCOqOC5q(MO rHCM-'tfiOCO00O5©rHCOHOS0dl>^00OC0^CMJt^050Q^0Q<^cdrH(»C0a5CMC0OTj?oil>rHI>cdcd05CMiQ HiO^NibHOOOHCOlOOOClNCloOiOCOHOOOHCOlOOOCMNlNXlOCMH^ tHCMCOiOCOlHGC05©tHCMH< lO l> O0C5 CM ^CO^L^O C^^^OOrH CO CO OOrH t^|> CM v r-TrH rH rH HH tH CM CM CM CM" - CM~CO COCO CO COrJHrtfH 3 '' TfTiOuOlO 00 300 cMoooocqoooocqoooooooooooooooooooooooo CM05©cdc0rHt>Oaic0TfiCMl0^C}rH05C0C0airHcic0Tj5©CMC01>l>C0C0cic0C0O H'^HtKO'^HOOOOOOOOOlNTHOOHCOi-iiOCOONlO'^COCOCO-^COOOHiOOiO tH tH CO ^ lO CO CO IH 00 05 tH CM CO cqiH_05_© CM^CO^uO r^ 05 rH CO GO © rH r-T rH r-T rH rH rH CM CM~ C0005OHCM CO CO 00 © tH CO lO© CO © CM r* COGO © 0M ^ ^ rHrHrHrHrHrHrHrHCMCMCMCMCMCMCOCOCOCOCOrfTlI'TjrcO o m CVI m CM CSI cMoooqpppppppoppppppppppppppppppoppoop ddHcciONHd^'coNdHd^Hdci’t^o6c>io>o'ddooo6ciiodcoo6dio HHOiOiOCOCOONLOCOCMCMIMCMCOHCOOCMiOOHCSiOHN^iMoOQOr'OON tHCMCOH O O © © OO pppppppppppppppppppppp oicdcM’tHOrHOOOCOOOCOH^ododcMrH^oiH^rHCO'asOCOiOOOCOOiCrHTfOCMQO COOOCOCOCOOOiOHCO'O^NHHHHMCOiOt'OCOCDOHOiOrtNTfHOr^OO HNCOCO^iOiCOt^QOOOH CM CO CO O CM CO p^CO 00O rH CO CM tH* rH rH HHHHHH C^CM" CM CM' CM" CM" CM'cO CO CO CO lC O o CM CMcoHOoqqoooqqqqooqqqqqqqqqqqqqqqqqqq odcMCOrHH5cOlOOaiCMOrHcdc001>05lOl005I>-'05cdcdOG(6cM‘ododH5cM’cdcMrJHO COt'(NOC5 , ctlOiO(NaiCOWHOOOt'l''Nt'OOC5HCOCOCOCMiOO^C5HOCOO iH CM CM CO Tft-iO rOCOl'-OOOOOH CM CO ^lO l^OOO O CM CO r^CO O rH CM IH rH rH rH rH rH rH rH r-T rH CM*~ CM" CM" cm" CM" CM" Cm" CO CO" -H 175 Hcocooopppppppppooop o o p p p p o o o o o o q o o o o l> 00 H 3 H 3 O I> CM © CM IH CO GO H 3 H? I'.' Tt? H 3 O0 CO l> rH 05 rH id Tf 3 CO lO H 3 CO* GO H 3 CC > CM* C!OOMOOiCOiOHN'rfHCOCDHMHOOCiOOH(N^COOOH^>HiOH iHrHCMCOCO^'^iOiOCOt^t^OOOS O rH CM CO CO lO CO GO O O tH CO t^GOrH rHrHrHrHrHrHrHrHrHrHCMCMCMCMCMCMCMTtr 150 HiOHOOoooqppppppppppppppppppppqpqppp COHiONCodcid^lNCicDddiOHdHCDrtiuidNN'ocdNcicOCOHONOOiQ Cn-OOOiOCliOO^O^OiCHl-'^OCOLOCOHOOC^NCOCOCOOQOaiHfNHlN rHCMCMCOCOCOTfHfUOCOCOXHGOGOCi O rHC^ C^ CO r)H_ipcpi>_i6HNddd(No6inicoi^’HcoidHc:dco CMt}fl>ClCOHiOQO''lCOHCDHOHNCOCiCOCOOI>H^qQONCOiOH^CO'^CO rH rH CM CM CM CO CO tP tP lO lO CO CO t> I> GO 05 © © H CM CO CO ' H^uOCO I> 00 p © 05 HHrHHHHHHHHH rH CM CM 001 Hcot>cooooooopopppppppppppppppppoooppp HrcdcdiOCM^CMOOrHiOrHCOGOOH^OGOCOOTjrOGOGOOH^rHOSoiCMCOCOrHCMO HMCOO^HOCOCOOCOCOOiOO^OOCOO^OiOHOO^HN^INONiOCOiO rHtHrHCMCMCMCMCOCOTP^TpLOiCCOCOI>COa00505 © tH^CM COCO rj^ipco CO HHHHHHHHHM Contents for 1 Ft. Length Gallons. OOCMCMQOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOO O CO IH OI © 05 tP 05 lO H GO lO CM © GO IH CO lO iO »0 CO Ih GCt O H O OOOOOOOOO HcOCDiOCMcOCMC50HHOOOOOC5COO>NH05f005NGOOHH020(NCOeOH(NO OHCocoo^t^05Ncoo5cocoo^qMcoMoq^qqHoo^HH^qqHiocoiO * * ’ ' rH rH rH rH CM CM CM* CO CO H 3 H 3 H 3 lO lO CO CO IH IH 00 05 05 © rH rH CM* CO CO H 3 lO CO CO THrHrHrHrHrHrHrHrHCM Cubic Feet. 8Ss!eS®SeSs!3SaS383SSS88gg8S88SRg8S8a OCM'HQ0C005C0C0OHtH05'H05'HOC0CMG0i0CM05C0TtrCMrH05G0lHtHCCC0C0lHG0'H OOOOHHWCMCOCOM'T^iO®qi>l>OOqqpH(NCOMrjJiqqi>OOqpHH rH rH rH rH rH rH rH rH rH tH rH CM CM CO Area. Sq. In. .7854 3.1416 7.0686 12.5660 19.6350 28.2740 33.1830 33.4850 44.1790 50.2650 56.7450 63.6170 70.8820 78.5400 86.5900 95.0330 103.8700 113.1000 122.7200 132.7300 143.1400 153.9400 165.1300 176.7100 188.6900 201.0600 213.8200 226.9800 240.5300 254.4700 268.8000 283.5300 298.6500 314.1600 452.3900 | japmi^o j jaioureia ^ ^ i v Hst^; Her^: -Isrt; Her^ Hcr^; He>t; 2|cr^ Hsr^ v ^ i; ^ ^ i ^ — iloiir -le.5- -taOOHH(M(NCOCOH'ctMOlCCOCDNHOOX05C50H HCMM^iC)CDCOIh1HOOG005C5HHHHHHHHHHHHHHHHHHHHCMN 1 gal. = 231 cu. in. = .13368 cu. ft. 1 gal. of water at 39.2° = 8.33888 lb. 1 cu. ft. of water = 7.48052 gal., and weighs 62.423 lb. 164 PUMP MA C II IS EE Y. MISCELLANEOUS FORMS OF WATER ELEVATORS. Jet Pump. — In this form, the energy of the jet of water is utilized for raising a larger volume through a small distance, or a mixture of w ater a solid material through a short distance. Vacuum Pump.—' The pulsometer, which is the most important representa- tive of this class, consists of two chambers in a large casting, with smtable automatic valves arranged at the top and bottom of the chambers, ^eain is fnttcS into o^of the chambers, then the valve at the top closed. This steam will condense, forming a vacuum that draws tv ater from the suction into^th” chamber, when tie chamber is filled with water, steam is again introduced and forces the water out through the discharge pipe. The oneratioTis then repeated, more water being drawn in by the condensation thp steam The two chambers work alternately, one being engaged m driving wSer in while the other forces it out. The total steam efeciency of this form of pump is s ma ll, though it may actually be abo\e that of -ma steam nummseumloyed in isolated portions of a mine. The advantages are that th^ ^pSLp Assesses no intricate mechanism,no reciprocating , parts, reauires no lubrication, and is not injured by gntty or acid materials. On this account it may be emploved for pumping water in concentration lvork s, coal-washing plants, and similar places where the water is liable to contain gnt A i r-Lift^P u m p s. — By introducing compressed air at submerged in anv liquid, the air in the pipe rises as bubbles, the^iecific gravity of the fluid in the pipe. This causes the fluid m the pipe to rise above the' level of that surrounding the pipe. The difference m soecific gravitv can never be great, and hence the fluid can never be llevated to anv considerable height withput having the lower endunmersed to a correspondingly^ great depth. On this account it is frequently necessary to drill a well considerably below the water-bearing strata, so as to obtain the proper ratio between the submerged portion of the pipe to which the water is to be lifted. Some advantages of this form of pump are that there are no moving parts, no lubrication is required, and gntty material does not interfere with the operation. If the pump is constructed of suitable material, it may be employed for handling acids or solutions in electrolvtic or chemical works. This style of pump is also quite extensiy ely employed fo? pumping water from Artesian wells. It has not been successful as a mine pump, owing to the ratio between the part immersed and the lift. Centrifugal Pumps.-The height of lift depends on the tangential velocity of the revolving disk of pump and the quantity of water discharged, and is proportional to the area of the discharge orifices at the circumference of the disk The most efficient total lift for the centrifugal pump is. approximately , 17 ft' and for small lifts the centrifugal pump is much more efficient than anv stvle of piston pump. For a given lift, the total efficiency of a centrif- ugal pump increases with the size of the pump. Centrifugal pumps are always designated bv the size of their outlet, as. for instance, a 2" or 4 pump meaning with a 2"' or 4" discharge pipe. Centrifugal pumps are not at all effective for dealing with great heads, and hence have never come into competition with piston pumps for this class of work. For lifting large volumes of water against a low head, as in irrigation or drainage problems, they are remarkably efficient. Under th ^ m( ^ ' ■^hait is" stances the efficiency of the centrifugal pump may be practically /(K. that is, the^ pump ^ma/v do an amount of work upon the water that is theoretically equal to 7(K of the power furnished to the pump, Pumping engines work- ing against high heads, and operated by the most improved class of engines, may attain an efficiency of practically 85ft. Centrifueal Pump as a Dredge.— When dredging is done by means of centrif- ugal pumps, a greater amount of power is necessary, and the pump be run at a greater speed than when pumping water, owing to the i fact ; that the fluid being handled has a greater density than water When dealing with fine sand, as much as 50 ft of the bulk of the material handled may be sand, though, as a rule, the amount of solid material m the water dredged only runs from 30# to 35# of the total. n , . Water Buckets.— Where only a limited amount of water collects m the mine workings it is frequentlv removed by means of a special water bucket ^r ^ater ca? during the houre that the hoisting engine would otherwise be i^e Where very large amounts of water are to be removed, it has also SINKING PUMPS. 165 been found economical to remove them by means of special water buckets. This is especially true in the case of deep shafts. One of the best illustrations of this class of work is the Gilberton water shaft, which has been equipped at the Gilberton Colliery of the Phila- delphia and Reading Coal & Iron Co. The collieries draining to this shaft require the removal of 6,000,000 gal. of water per 24 hours during the wet season, and this has to be lifted from a depth of 1,100 ft. In order to accom- plish the work by means of steam pumps, it required a number of pump stations in different parts of the mine, each of which had to be attended by a pumpman, and a large number of steam lines were required in the mine. In order to remove the danger of fire caused by these steam lines, and to dispense with the large amount of labor otherwise necessary, it was decided to hoist the water, and a shaft 22 ft. x 26 ft. 8 in. outside of timbers, was sunk. This shaft contains two compartments 7 ft. X 7 ft., in which the water buckets are operated, and two compartments 7 ft. X 11 ft. 8 in. that are utilized for cages to lower men, timber, and other supplies. The water tanks employed in the special water compartments are 5 ft. 6 in. in diameter, and 14 ft. long. They are provided with a special device sliding on regular cage guides, and empty themselves automatically at the surface by means of a trip or sliding valve. Two pairs of direct-acting hoisting engines, with 45" X 60" cylinders, operating drums 14 ft. 8 in. in diameter by 15. ft. face, are employed. These operate the water buckets in cages by means of 2" crucible steel ropes, at 50 revolutions per minute, which is equivalent to a piston speed of 500 ft. per minute. The drums will hoist two tanks of 2,400 gal. per minute. This gives an output of 7,000,000 gal. per 24 hours. By slightly increasing the speed of the engine this amount can be increased 10#, which is 25# in excess of the calculated maximum demand on the shaft. The cages in the cage compartments are so arranged that they can be discon- nected, and water buckets substituted for them. This would be a total output of over 14,000,000 gal. per 24 hours at the normal speed of the engine. One great advantage of this style of pumping plant is that there is absolutely no fear of drowning the pumps. Some years ago the Hamilton iron mine, in Michigan, was drowned by a sudden inrush of water that drove the pumpmen from the pumps. In order to remove this large volume of water, special bailing buckets were substituted for the ordinary mine skips. These bailing buckets ran on the inclined skip road, and un watered the mine in a remarkably short time. Sinking Pumps.— Sinking pumps may be either single or duplex in their action, and may be inside or outside packed. Outside-packed single-acting pumps are in many ways preferable, owing to the fact that they are less liable to get out of order. One requisite of any sinking pump is that it should have as few exposed parts as possible, and that these parts should be so placed that they will be protected from injury by blasting to as great an extent as possible. Sinking pumps are usually provided with a telescopic section in the suction pipe, and sometimes also in the discharge pipe, so that they can be moved down several feet without having to break the joints of the piping. Pumps for Acid Waters.— Where mine waters are acid in their nature, brass or brass-lined pumps are usually employed, and in some cases even wooden pumps have been used, as, for instance, in the Swedish copper mines, though this prac- tice is disappearing in favor of the use of brass or copper linings. The pipes for such pumps should be of brass or copper tubing, or should be lined with some substance that will not be affected by the acid of the water. Sometimes wooden linings are em- ployed, placed as shown in Figs. 21 and 22, Fig. 21 being a section of the pipe with the lining complete, and Fig. 22 a cross-section of one of the individual boards used in the lining. These are usually made of pine about | in. thick, and are grooved on each end as shown. They are sprung in so as to complete a circle on the inside of the pipe, and then long, thin, wooden keys driven into the grooves. When the water is allowed to go into the pipes, the linings swell and make all joints perfectly tight. Elbows and other crooked sections are lined with sheet lead beaten in with a mallet, Fig. 21. 166 FUELS. FUELS. The value of any fuel is measured by the number of heat units that its combustion will generate, a unit of heat being the amount required to heat 1 lb of water 1° F. The fuels used in generating steam are composed mainly of carbon and hydrogen, ash, and moisture, with sometimes small quantities of other substances not materially affecting their value. Combustible is that portion which will burn; the ash or residue vanes from 2$ to 36$ in different fuels. , , The following table gives, for the more common combustibles, the. air reauired for complete combustion, the temperature with different proportions of air the theoretical value, and the highest attainable value under a steam boiler assuming that the gases pass off at 320°, the temperature of steam at 75 lb pressure, and the incoming draft to be at 60°; also that with chimney draft twice and with blast only the theoretical amount of air is required for combustion. Table of Combustibles. Kind of Combustible. ft 3 < & oft ft ft t- 1 3 |I o o ft Temperature of Combustion. i Highest Theoretical Attainable ;ite.... J Hydrogen .... Petroleum . .. ( Charcoal Carbon -< Coke (Anthracite Coal, Cumberland, Coal, Coking bituminous Coal, Cannel Coal, Lignite Peat, Kiln dried Peat, Air dried, 25$ water Wood, Kiln dried Wood, Air dried, 20$ water 36.00 5,750 15.43 5,050 | 12.13,4,580 . O Sh S3 So ft >> ^ ft ft ft ft 3 © . 0”-\ ©<1 in . © >> 3ft ft^ 73 o 3,860 3,515 3,215 aj f-i ft ©v* - r— ; O ft © t-' ft- © O 3ft ft ft ^ ft © 3 ft o ^O 2.8601,940 2,710;1,850 Value. 3®© f-l 'ft Q Sb c3 CO ■SSS CO Q. O •So « f 62,032 21,000 2,440 1,650 14,500 12.06,4,900 3,360 11.73 5,140 3,520 11.80 4,850 3,330 9.30 4,600 3,210 7.6814,47013,140 5.76 4,000 2,820 6.00 4,08012,910 4.80 3, 700 ; 2, 607 1 2, 100 j 1 ,490 2,550|l,730 2,680,1,810 2,5401,720 2,490:1,670 2,4201,660 2,2401,550 2,260; 1,530 c5 0 © ft^ft ■ga o o ^ C l— t £|£ rH °ft ft ,dftft - © > u C © o3 64.20 21.74 15.00 Value Un- der Boiler. o3 Ut ft © a 3 ft o ft 15,370 15.90 15,837 16.00 15,080 15.60 11,745! 12.15 9,660 7,000 7,245 5,600 | 10.00 7.25 7.50 5.80 18.55 13.30 14.28 14.45 14.01 10.78 8.92 6.41 6.64 4.08 19.90 14.14 15.06 15.19 14.76 11.46 9.42 6.78 7.02 4.39 The effective value of all kinds of wood per pound when dry, is substan- tially the same. This is usually estimated at .4, the value of the same weight of coal. The following are the weights and comparative values of different woods by the cord: Wood. Hickory (shell bark) Hickory (red heart) White oak Red oak.. Spruce New Jersey pine Weight. 4,469 3,705 3,821 3,254 2,325 2.137 Wood. Beech Hard maple.... Southern pine. Virginia pine . Yellow i>ine.. ... White pine Weight. 3,126 2,878 3,375 2,680 1,904 1,868 SLACK. 167 Much is said nowadays about the wonderful saving that is to be expected from the use of petroleum for fuel. This is all a myth, and a moment’s attention to facts is sufficient to convince any one that no such possibility exists. Petroleum has a heating capacity, when fully burned, equal to from 21,000 to 22,000 B. T. U. per lb., or, say, 50$ more than coal. But, owing to the ability to burn it with less losses, it has been found, through extended experiments by the pipe lines, that under the same boilers, and doing the same work, 1 lb. of petroleum is equal to 1.8 lb. of coal. The experiments on locomotives in Russia have shown practically the same value, or 1.77. Now, a gallon of petroleum weighs 6.7 lb. (though the standard buying and selling weight is 6.5 lb.), and therefore an actual gallon of petroleum is equivalent under a boiler to 12 lb. of coal, and 190 standard gallons are equal to a gross ton of coal. It is very easy with these data to determine the relative cost. At the wells, if the oil is worth, say, 2 cents a gallon, the cost is equivalent to $3.80 per ton for coal at the same place, while at, say, 3 cents per gallon, the lowest price at which it can be delivered in the vicinity of New York, it costs the same as coal at $5.70 per ton. The Standard Oil Company estimates that 173 gal. are equal to a gross ton of coal, allowing for incidental savings, as in grate bars, carting ashes, attendance, etc. Sawdust can be utilized for fuel to good advantage by a special furnace and automatic feeding devices. Spent tan bark is also used, mixed with some coal, or it may be burned without the coal in a proper furnace. Its value is about one-fourth that of the same weight of wood as it comes from the press, but, when dried, its value is about 85$ of the same weight of wood in same state of dryness. It has been estimated that, on an average, 1 lb. of coal is equal, for steam- making purposes, to 2 lb. dry peat, 2} to 2\ lb. dry wood, 2\ to 3 lb. dried tan bark, 2f to 3 lb. cotton fetalks, 3i to 3£ lb. wheat or barley straw, and 6 to 8 lb. wet tan bark. Natural gas varies in quality, but it is usually worth 2 to 2£ times the same weight of coal, or about 30,000 cu. ft. are equal to a ton of coal. Slack, or the screenings from coal, when properly mixed— anthracite and bituminous— and burned by means of a blower on a grate adapted to it, is nearly equal in combustible value to coal, but its percentage of refuse is greater. The accompanying table of proximate analyses and heating values of American coals was compiled by Mr. William Kent, for the 1898 edition of the Babcock & Wilcox Co.’s book, “ Steam.” The analyses are selected from various sources, and, in general, are averages of many samples. The heating values per pound of combustible are either obtained from direct calorimetric determinations or calculated from ultimate analyses, except those marked (?), which are estimated from the heating values of coals of similar composition. The figures in the last column are obtained # by dividing the figures in the preceding column by 965.7, the number of heat units required to evaporate 1 lb. of water - at 212° into steam of the same temperature. The heating values per pound of combustible given in the table, except those marked (?), are probably within 3$ of the average actual heating values of the combustible portion of the coals of the several districts. When the percentage of moisture and ash in any given lot of coal is known, the heating value per pound of coal may be found, approximately, by multi- plying the heating value per pound of combustible of the average coal of the district by the difference between 100$ and the sum of the percentages of moisture and ash. The heating effect is calculated on the basis of the coal burned to carbon dioxide and liquid water at 100° C., and is stated either in calories per kilo- gram or English heat units per pound. The theoretical evaporative effect is calculated by dividing the number of calories per kilogram by 536, or the number of English heat units per pound by 965. In either case, it expresses the theoretical number of kilograms or pounds of water converted into steam from and at 100° C., by 1 kilogram or 1 lb. of coal. A committee of the Western Society of Engineers, of Pittsburg, report that 1 lb. of good coal = 7£ cu. ft. of natural gas. When burned with just enough air, its temperature of combustion is 4,200° F. The Westinghouse Air Brake Co. found from experiment that 1 lb. Youghiogheny coal = 12£ cu. ft. natural gas, or 1,000 cu. ft. natural gas = 81.6 lb. coal. Indiana natural gas gives 1,000,000 B. T. U. for 1,000 cu. ft. and weighs .045 lb. per cu. ft. 168 FUELS. Proximate Analyses and Heating Values of American Coals. Coal. Anthracite. Northern Coal Field . East Middle Coal Field West Middle Coal Field Southern Coal Field . Semianthracite. Loyalsock Field . . Bernice Basin . . . Semibituminous. Broad Top, Pa. . . . Clearfield Co., Pa. . . Cambria Co., Pa. . . Somerset Co., Pa. . . Cumberland, Md. . . Pocahontas, Ya. . . . New River, W. Ya. . Bituminous. Connellsville, Pa. . . Youghiogheny, Pa. . Pittsburg, Pa. . . . Jefferson Co., Pa. . . and Ohio .... Thacker, W. Va. . . Jackson Co., Ohio . . Brier Hill, Ohio . . Hocking Valley, Ohio . Yanderpool, Ky. . . Muhlenberg Co., Ky. . Scott Co., Tenn. . . Jefferson Co., Ala. . . Big Muddy, 111. . . • Mt. Olive, 111 Str^ator, 111 Missouri . . . . • • Lignite and Lignitic Cot Iowa Wyoming Utah Oregon lignite . . . Moisture. Volatile Matter. Fixed Carbon. Ash. Sulphur. Heating Value per Lb. Coal, B. T. U. 1 Volatile Matter Per Cent, of Combustible. Fixed Carbon. Per Cent, of Combustible. Heating Value per Lb. Combustible. 1 Theoretical Evaporation 3.42 4.38 83.27 8.20 .73 13,160 5.00 95.00 14,900 1 3.71 3.08 86.40 6.22 .58 13,420 3.44 96.56 14,900 1 3.16 3.72 81.59 10.65 .50 12,840 4.36 95.64 14,900 1 3.09 4.28 83.81 8.18 .64 13,220 4.85 95.15 14,900 1 1.30 8.10 83.34 6.23 1.63 13,920 8.86 91.14 15,500 1 .65 9.40 83.69 5.34 .91 13,700 10.98 89.02 15,500 1 .79 15.61 77.30 5.40 .90 14,820 17.60 82.40 15,800 1 .76 22.52 71.82 3.99 ; .91 14,950 24.60 75.40 15,700 ] .94 19.20 71.12 7.04 1.70 14,450 22.71 77.29 15,700 1.58 16.42 71.51 8.62 1.87 14,200 20.37 79.63 15,800 ’ 1.09 17.30 73.12 7.75 .74 14,400 19.79 80.21 15,800 1.00 21.00 74.39 3.03 .58 15,070 22.50 77.50 15,700 .85 17.88 77.64 3.36 .27 15,220 18.95 81.05 15,800 1.26 30.12 59.61 8.23 .78 14,050 34.03 65.97 15,300 1.03 36.50 59.05 2.61 .81 14,450 38.73 61.27 15,000 1.37 35.90 52.21 8.02 1.80 13,410 41.61 58.39 14,800 1.21 32.53 60.99 4.27 1.00 14,370 35.47 64.53 15,200 L. 1.81 35.33 53.70 7.18 1.98 13,200 40.27 59.73 14,500 ' 1.93 35.90 50.19 9.10 2.89 13,170 43.59 56.41 14,800 1 1.38 35.04 56.03 6.27 1.28 14,040 39.33 60.67 15,200 , 3.83 32.07 57.60 6.50 13,090 35.76 64.24 14,600 4.80 34.60 56.30 4.30 13,010 38.20 61.80 14,300 6.59 34.97 48.85 8.00 1.59 12,130 42.81 57.19 14,200 4.00 34.10 54.60 7.30 12,770 38.50 61.50 14.400 4.33 33.65 55.50 4.95 1.57 13,060 38.86 61.14 ' 14,400(?) | 1.26 35.76 53.14 8.02 1.80 13,700 34.17 65.83 1 15,100(?) | 1.55 34.44 59.77 2.62 1.42 13,770 37.63 62.37 14,400(?) | 7.50 30.70 53.80 8.00 12,420 36.30 63.70 ! 14,700 . 11.00 35.65 37.10 13.00 10,490 i 47.00 53.00 13,800 12.00 33.30 40.70 14.00 10,580 i 45.00 55.00 14,300 . 6.44 37.57 47.94 8.05 12,230 i 43.94 56.06 14,300(?) s. 8.45 37.09 35.60 18.86 8,720 ) 51.03 48.97 ! 12,000(?) 8.19 38.72 41.83 11.26 10,390 > 48.07 51.93 12,900(?) 9.29 41.97 44.37 3.20 1 .18 i 11,030 ) 48.60 51.40 1 ]2,600(?) . 15.25 42.98 33.32 7.11 1.6( 5 8,540 ) 54.95 45.05 11,000(?) % I 15.84 15.53 15.32 15.74 15.01 15.32 15.74 15.11 14.91 14.91 15.63 14.91 15.22 14.29 14.80 14.80 12.42 13.35 13.04 11.39 A British therma un t (B. T. U.) is me quantity ui neat — v. temperature ofl lb. of water 1° F. at or near the temperature of maximum density, 89.1° F. _ , . , A calorie is the quantity of heat required to raise the temperature of 1 kilogram of water 1° C. at or about 4° C. A pound calorie is the quantity of heat necessary to raise the temperature of 1 lb. of water 1° C. . . . . . 1 French calorie = 3.968 British thermal units. 1 B T U. = -252 calorie. lib. calorie = | B. T. U. = .4536 calorie. The heating value of any coal may be calculated from its ultimate analysis, with I probable error not exceeding by Dulong s formula: Heating value per lb. = 146 C + 620 ( H — — ^ , in which C ; H, and 0 are, respectively, the percentages of carbon, hydrogen, and oxygen. CLASSIFICATION OF COALS. 169 ?>• in which C, 0, H, and S represent the weights of carbon, oxygen, hydro- gen, and sulphur in 1 lb. of the substance. Composition of Fuels. ( Mechanical Draft, B. F. Sturtevant Co.) Heat in pound calorie = 8,080 C + 34,462 (^H — or = 8,080 C + 34,462 ) + 2,250 S. T. U. — 14,650 C -f 62,100 (ll — y ) Heat in B. Description. Carbon. Hydro- gen. Oxy- gen. Nitro- gen. Sul- phur. Ash. Anthracite. France 90.9 1.47 1.53 1.00 .80 4.3 Wales 91.7 3.78 1.30 1.00 .72 1.5 Rhode Island 85.0 3.71 2.39 1.00 .90 7.0 Pennsylvania 78.6 2.50 1.70 .80 .40 14.8 Semibituminous. Maryland 80.0 5.00 2.70 1.10 1.20 8.3 Wales 88.3 4.70 .60 1.40 1.80 3.2 Bituminous. Pennsylvania 75.5 4.93 12.35 1.12 1.10 5.0 Indiana 69.7 5.10 19.17 1.23 1.30 3.5 Illinois 61.4 4.87 35.42 1.41 1.20 5.7 Virginia 57.0 4.96 26.44 1.70 1.50 8.4 Alabama 53.2 4.81 32.37 1.62 1.30 6.7 Kentucky 49.1 4.95 41.13 1.70 1.40 7.2 Cape Breton 67.2 4.26 20.16 1.07 1.21 6.1 Vancouver Island 66.9 5.32 8.76 1.02 2.20 15.8 Lancashire gas coal 80.1 5.50 8.10 2.10 1.50 2.7 Boghead cannel 63.1 8.90 7.00 .20 1.00 19.8 Lignite. California brown 49.7 3.78 30.19 1.00 1.53 13.8 Australian brown 73.2 4.71 12.35 1.11 .63 8.0 Petroleum. Pennsvl vania (crude) 84.9 13.70 1.40 Caucasian (light) 86.3 13.60 .10 Caucasian (heavy) 86.6 12.30 1.10 Refuse 87.1 11.70 1.20 CLASSIFICATION, COM POSITIO: J, AN D PROPERTIES OF COALS. Coals may be broadly divided into two classes: Anthracite, or hard, coal; and bituminous, or soft, coal. Anthracite, or Hard, Coal.— Specific gravity, 1.30 to 1.70. This is the densest, hardest, and most lustrous of all varieties. It burns with little flame and no smoke, but gives a great heat. Contains very little volatile combustible matter. Color, deep black, shining; sometimes iridescent. Fracture, conchoidal. Semianthracite coal is not so dense nor so hard as the true anthracite. Its percentage of volatile combustible matter is somewhat greater, and it ignites more readily. Bituminous, or Soft, Coal.— Specific gravity, 1.25 to 1.40. It is generally brittle; has a bright pitchy or greasy luster, and is rather fragile as compared with anthracite. It burns with a yellow smoky flame, and gives, on distil- lation, hydrocarbon oils or tar. Under the term “bituminous” are included a number of varieties of coal that differ materially under the action of heat, giving rise to the general classification: Coking or caking coals, and free-burning coals. Semibituminous coal has the same general characteristics as the bituminous, although it is usually not so hard, and its fracture is more cuboidal. The 170 FUELS. nercentage of volatile combustible matter is less. It kindles readily, and burns quickly with a steady fire, and is much valued as a steam coal. Coking coals are those that become pasty or semiviscid in the fire, and, when heated in a close vessel, become partially fused and agglomerate into a mas? of ^coherent coke. This property of coking may, however, become Seatly impaired, if, indeed, not entirely destroyed, by weathering. Free-burning coals have the same general characteristics as the cokm^ coals but they burn freely without softening, and do not fuse or cake t0S slkl o?arZaduUblacTcolor, and is much harder and less frangible than "he coMng coal. It is readily fissile, like slate, but breaks with difficulty on cross-fracture. It ignites less readily, but makes a hot fire, constituting a good house coal. Weights and Measurements of Coal. ( Coxe Bros. & Co., Chicago , III.) Coal. Lehigh lump Lehigh cupola Lehigh broken Lehigh egg Lehigh stove Lehigh nut Lehigh pea Lehigh buckwheat... Lehigh dust Weight per Cubic Foot. Pounds. Cubic Feet per Ton, 2,000 Lb. 55.26 36.19 55.52 36.02 56.85 35.18 57.74 34.63 58.15 34.39 58.26 34.32 53.18 37.60 54.04 37.01 57.25 34.93 Coal. Free-burning egg... Free-burning stove Free-burning nut ... Pittsburg Illinois ' - Connellsville coke Hocking Indiana block Erie Ohio cannel * 1.8 US ’S-Si A 2 56.07 56.33 56.88 46.48 47.22 26.30 49.30 43.85 48.07 49.18 - . 0^0 f-i o ^ ®o 35.67 35.50 35.16 43.03 42.35 76.04 40.56 45.61 41.61 40.66 Cannel coal differs from the ordinary bituminous coal in its texture. It is compact with little or no luster and without any appearance of a banded structure. It breaks with a smooth conchoidal fracture, kindles readily, and burns with a dense smoky flame. It is rich in volatile matter, and makes an excellent gas coal. Color, dull black and grayish black. Uenffe or brown coal, often has a lamellar or woody structure; is some- times pitch black, but more often rather dull and brownish black. It kindles readily and burns rather freely with a yellow flame and comparatively little smoke but it gives only a moderate heat. It is generally non-coking. The nercentage of moisture present is invariably high from 10^ to 30/). The subdivisions given above are entirely arbitrary, as the different varieties of coal are found to shade insensibly into one another. The follow- ing are two classifications according to percentages of volatile combustible matter: „ Classification of Coal According to Volatile Combustible. Coal. Per Cent. Kent. Per Cent. 2.5 to 6 0 to 7 An till dci ic * 7 to 10 7.5 to 12 12 to 20 12.5 to 25 oGiniulluiiLiiiuuo over 20 25 to 50 I) 1 LlIILLlllU over 50 - _ . . The ComDosition of Coals.-A proximate analysis determines tne proport of those products of a coal having the most important bearing on its uses. Th^subsCces as usually presented are: Moisture, or water, volatile com- PROPERTIES OF COALS . 171 bustible matter, fixed carbon, sulphur, and ash. In addition to these, the following physical properties are generally given: Color of ash, specific gravity, and strength or hardness. The determination of these eight factors gives a fair general idea of the adaptabilities of a coal. Moisture, or water, in coal, has no fuel value, is an inert constituent, dug, handled, and hauled, and finally expelled at a cost of fuel. Each per cent, of moisture means 20 lb. less fuel for each ton of coal. Volatile combustible matter is an important constituent of coal, the amount and quality deciding whether a coal is suitable for the manufacture of illuminating gas. The coking of coal also is largely dependent on this constituent. When a large percentage of volatile combustible matter is present, coals ignite easily and burn with a long yellow flame, and, in ordinary combustion, give out dense smoke, and form soot. This quality makes a fuel objectionable for railway and sometimes for naval use. The fixed carbon is the principal combustible constituent in coal, and, in bituminous and semibituminous coals, the steaming value is in proportion to the percentage of fixed carbon. Though the fixed carbon of a coal evapo- rates much less water than an equivalent weight of the volatile combustible matter when properly burnt, in practice, so much of the latter is lost through careless firing, or improper furnace construction, that the relative steaming value of a coal may be fairly approximated by assuming the carbon to be the only useful constituent. Sulphur will burn and develop heat, and is not inert like moisture and as}i. But it corrodes grates and boilers; in the blast furnace it injures iron, and produces a hot short pig, and is objectionable in coal for forge use. In gas making, the sulphur must be removed. It usually occurs in coal in the form of iron pyrites, which, oxidizing, causes disintegration, and sometimes spontaneous combustion. It is then an element of danger and loss. Ash is an inert constituent, which means 20 lb. of weight to be handled and 20 lb. loss per ton of coal for each per cent, present. Water in coal is removed at the cost of fuel, while ashes are removed at extra cost of labor. It is estimated that if the cost of stoking coal is 6 f0 of the cost of coal (coal at $3.00 per ton, and labor at $1.00 per day), and with cost of handling ashes double that of stoking coal, 5$ of ash will lessen the fuel value of coal over 6$; 10 0 ash, over 120; and so on. The color of the ash furnishes a rough estimate of the amount of iron con- tained in a fuel. Iron in an ash makes it more fusible, and increases its tendency to clinker. In domestic consumption, where the temperature is low, the quantity of ash is of more importance than its fusibility, but for steam purposes, where an excessive heat is required, ashes of a clinkering coal will fuse into a vitreous mass and accumulate upon the grate bars and exclude the passage of necessary air. The practicability of employing a coal will often be determined by the quality of the clinkering of the ashes. Under such conditions, such coals are best whose ashes are nearly pure white and which contain little or no alkali nor any lime, and do not contain silica and alumina. The specific gravity is an important factor when there is restriction of I space, as on railway cars and in ship bunkers. A given bulk of anthracite ! coal will weigh from 100 to 150 more than the same bulk of bituminous coal, so that from 100 to 150 more pounds of fuel can be carried in the same place. The average specific gravity of anthracite coal is 1.5, and a cubic yard weighs about 2,531 lb. The average specific gravity of American bituminous coals, and of grades intermediate between them and anthracite, is about 1.325, and 1 cu. yd. weighs about 2,236 lb. Strength or hardness is valuable in preventing waste. In soft coal, much is ground to dust in mining and at the tipple. In railway transportation, soft coal is crushed, which further increases the loss, and the coal reaches market in bad condition. A very soft coal is shipped m lump, and is not in so wide demand. For marine use, a soft coal is objectionable, because of disintegra- tion by the motion of the ship. Strength is a requisite for the use of raw coal in the blast furnace, and also to prevent excessive loss of coal through the grates in ordinary furnaces. Steaming Coals— For steam making, the superiority of coals high in com- bustible constituents is admitted, and those with the higher percentage of fixed carbon are the most desirable. But the consideration of the steaming qualities of a coal involves, also, a consideration of the form of furnace and of all the conditions of combustion. The evaporative power of a coal in 172 FUELS. Dractice cannot be stated without reference to the conditions of combustion, and every practical test of a coal, to be thorough, should lead to ^determi- nation of the best form of furnace for that coal, anu slmuld furnish knowl- edge as to what class of furnaces in actual use such coal is specially adapted. Tt fs not sufficient that in comparative tests of coals the same conditions should ex?s? w!?h each, but there should also be determined the best co: Ofraals 1 high a in fixed carbon, the semianthracites and the semibitumi- nous rank as high as the anthracites in meeting the various requirements of a ^Fo? railway < use, t these^co^ls'^ave been found to excel anthracites in evaporating power. The comparative absence, m semibitummous coals, of smoke which means loss of combustible matter as well as discomfort to the traveler is sufficient to suggest the superiority of these coals over bituminous coals for such use In fact the high rate of combustion and the strong drait necessary ^n locomotiv e s is particularly unfavorable to the economic com- hnstTon of bituminous coal. Such semibitummous coals are also specially well suited ^for^mall tubular boilers, firebox steam boilers, or other forms with small uifiined combustion chambers, in which the gases from bitumi- nous coals become cooled, are not burnt, and deposit soot m nT1( q Steaming coal should kindle readily and burn quickly but steadily , and should contain only enough volatile matter to insure rapid combustio n . I should be low in ash and sulphur, should not clinker, and when it is t tra Coafsfo? Ircm 'Makfng^.— J th?manufarture^rf iron and forme— cal •nnrrioses coal is chiefly used after being converted into coke, though it is also P used to a limited extent in the raw state. Coal directly used must be «tronp- and not swell nor disintegrate so as to choke the furnace. It .hould be cafable of producing a high heat and should not contain a large amount 0f S Co\ P e h -Cok^s tCfaed carbon of a coal, a.fused and porous product pro- duced by the distillation of the gaseous constituent. For metallurgical use, t ^hoi fl be firm tough, and bright, with a sonorous ring, and should InuSn not over ’k of sulphur. For blast-furnace use, a dense coke is nhWtLable Ind the best i^the one with the largest cell structure and the hardest cell wall. A high percentage of volatile hydrocarbon is, as a rule, ne TMXfit?of C the in cMboi; the amount of disposable hydrogen, the tenacftv whh wL?h the gaseous’ constituents are held, all affect the recite iected'^ the^nflue’nee a of^^e 1S \^Sher”loses its^apacityfor coking. The antH r^the 'prcsCTit^rajde^of manufacture the ccontial mi a ii ties of a good coking coal are: that it shall contain not less than a manner f to form {“T^ofTolaSfmatter^ it will not fuse properly wmmi^it has more Ithan 3CH the porous structure will be unduly developed Wsf S ail.^and 0 therefOTe^ do* riot coke whife others fuse properly but give off their gas so as to form large “rSSIS ffiSwaafK the "lttsDurg o+ntidard coking coal, but coals whose analysis differ very instance, the Pocahontas coke, Virginia. ANALYSIS OF. COAL. 173 Domestic Coals. — In domestic use, coal is burned in open grates, in closed stoves with ordinary fire bowls and flat grates, or with basket grates in small furnaces for hot-air heating, and in cooking stoves. In all these, the coal that sustains a mild, steady combustion, and remains ignited at a low tem- perature with a comparatively feeble draft, is the best. A coal burning with a smoky flame is objectionable as producing much soot and dirt, especially for open grates or cooking purposes. For self-feeding stoves, or for base burners, a dry non-coking coal is necessary. A very free and fiercely burn- ing coal is not desirable, particularly in stoves, as the temperature cannot be easily regulated. A sulphurous coal is also bad, as it produces stifling gases with a defective draft, and corrodes the grates and fire bowls. The difficulty from clinkering is not so great in domestic uses, as the temperature is not generally high enough to fuse the ash. A stony, hard ash that will not pass between the grate bars is bad, and light pulverulent ash is best. Gas Coals.— Mr. H. C. Adams, of The American Gas Light Association, says: “ The essentials of a good gas coal are a low percentage of ash, say 5 $, and of sulphur, say £ of 1$, a generous share, say 37$ to 40$ of volatile matter, charged with rich illuminating hydrocarbons. And it should yield, under present retort practice, 85 candle-feet to the pound carbonized. It should be sufficiently dense to bear transportation well, so that, when carried long distances, it may not arrive at its destination largely reduced to slack or fine coal of the consistency of sand. And it should possess coking qualities that will bring from the retorts, after carbonization, about 60$ of clean, strong-, bright coke.” Blacksmith Coals.— A good coal for blacksmith purposes should have a high heating power, should contain a very small amount of sulphur, if any, should coke sufiflciently to form an arch on the forge, and should also be low in ash. From the above, it is readily seen that the analysis of a coal does not necessarily determine its value or the uses to which it can be put. How- ever, by examining the analyses given in the table on page 168, certain standards may be adopted as showing in a general way about what the analysis of coal should be for certain purposes. For steam purposes, the semibituminous coals have established reputations. For gas coals, that from Youghiogheny, Pa., is well known. For blacksmiths, Broad Top and Tioga County, Pennsylvania, coals are standards; while for coking, Connells- ville is recognized as a standard. The sizes of anthracite coal vary. The sizes of screen mesh and bar open- ings used for separating, range as follows: Lump, over bars placed 7 to 9 in. apart. Steamboat, over bars placed 3£ to 5 in. apart and through bars 7 in. apart. Grate, over 2£ in. and through 4£ in. square mesh. Egg, over 2 in. and through 2£ in. square mesh. Stove, over If in. and through 2 in. square mesh. Chestnut, over £ in. and through If in. square mesh. Pea, over £ in. and through £ in. square mesh. Buckwheat, over £ in. and through £ in. square mesh. No. 2 Buckwheat, or Bird’s-eye, over £ in. and through x 8 ff in. square mesh. The sizes of bituminous coal are Lump, Nut, and Slack. All coal that passes over bars 1£ in. apart is called Luw,p. All coal that passes through bars 1£ in. apart and over bars £ in. apart is called Nut. All coal that passes through bars £ in. apart is called Slack. ANALYSIS OF COAL. The following is the outline of the method recommended for the analysis of coal by a committee of the American Chemical Societv. Messrs . VV. F. Hillebrand, C. B. Dudley, and W. A. Noyes: Sampling.— At least 5 lb. of coal should be taken for the original sample, with care to secure pieces that represent the average. These should be broken up and quartered down to obtain the smaller sample, which is to be reduced to a fine powder for analysis. The quartering and grinding should be carried out as rapidly as possible, and immediately after the original sample is taken, to prevent gain or loss of moisture. The pow- dered coal should be kept in a tightly stoppered tube, or bottle, until analyzed. Unless the coal contains less than 2$ of moisture, the shipment of large samples in wooden boxes should be avoided. 174 FUELS. In boiler tests shovelfuls of coal should be taken at regular intervals and out in a tight covered barrel, or some air-tight cbvered receptacle, and the Fatter sLufd be placed whereit is protected from the heat of the furnace In sampling from a mine , the map of the mine should be carefully examined and points for sampling located m such a manner as to fairly rporesent the body of the coal. These points should be placed close to the ^kinS facl hefore sampling, make a fresh cut of the face from top to bottom^o a depth that will insure the absence of possible changes or of sulphur and smoke from the blasting powders. Clean the floor and spread Tmece of canvas to catch the cuttings. Then, with a chisel, make a cutting from floor to roof, say 3 in. wide and about 1 in. deep. Do not chisel out the shale or other impurities that it is the practice at that flame to reject. Measure the length of the cutting made, but do not include the impurities ^tMs measurement? With a piece of flat iron and a hammer break all nieces to quarter-inch cubes or less, without removing from the cloth. Quarter down and transfer to a sealed bottle or jar. For the r\ samnle samples taken at several points in this manner should be mixed and^iuartered down. If the vein varies in thickness at different points, the ^mnles taken at each point should correspond in amount to the thickness vein For instance, a small measure may be filled as many times with the coal of the sample as the vein is feet m thickness. Should the e appear differences in the nature of the coal, it will be more satisfactory to tekrfn adSon to the general sample, samples of such portions of the V6i ■oK-Srlg’ ofthe d coal“ open porcelain or platinum crucible at 104° to 107° C. for 1 hour, best in a double-walled bath containing pure t0l Volatile Combustible ^ Matter.— Placelgfof fresh, undried coal in a platinum crucible weiehing 20 to 30 g„ and haying a tightly fitting coyer Heat over thpTll flame of a Bunsen burner for 7 minutes. The crucible should be the lull name o triangle with the bottom 6 to 8 cm. above the top n7t? 1P burner %he flame use! should be fully 20 cm. high when burning free Ind the determinSfon made in a place free from drafte. The upper Jfrfkce of the cover should burn clear, but the under surface should remain covered with carbon. To find “ volatile combustible matter, «nhtrnet the percentage of moisture from the loss found here. SU ^sh — Burr^Se^ortfon of coal used for the determination of moisture at first over a very low flame, with the crucible open and inclined, untilfree from carbon If properly treated, this sample can be burned much more quSkly than the dJnse carbon left from the determination of volatile ma Fixed Carbon.-This is found by subtracting the percentage of ash from the percentage of coke. _ Mix thoroughly 1 g. of the finely powdered coa S lw P hh lg of magnesium oxide and.£ g. of dry sodium carbonateinathm 7 ?toToOc c platinum dish or crucible. The magnesium oxide should be triangle ove^analcoho? lT£p P heid KTS affirsf)^ mu^not be ?nals The flame is kept in motion and barely touching the dish, at first, fhen’lL carbon 60 c. c. oi warer. a™ '' , . through a filter, boil a second and third ?iSe n wUh 3 o"oTwfter%n e rlsh unfil the filtrate gives only a slight opalescence with Over hydrochloric acid Snl SCfn^is^ especially at^first, ^ with oonstant^irring, 10 iS ln r the case of coals containing much pyrites or calcium sulphate, the STEAM. 175 > residue of magnesium oxide should be dissolved in hydrochloric acid and the solution tested for sulphuric acid. When the sulphur in the coal is in the form of pyrites, that compound is converted almost entirely into ferric oxide in the determination of ash, and, since 3 atoms of oxygen replace 4 atoms of sulphur, the weight of the ash is less than the weight of the mineral matter in the coal by f the weight of the sulphur. While the error from this source is sometimes considerable, a correction for “proximate” analyses is not recommended. When analyses are to be used as a basis for calculating the heating effect of the coal, a correction should be made. The analysis of a coal may be reported in three different forms, as per- centages of the moist coal, of the dry coal, or of the combustible. Thus, suppose 1 g. of coal is analyzed, and the first heating shows a loss of weight of .1 g., the second of .3 g., the third .5 g., the remainder, or ash, weighing .1 g., the complete report would be as follows: Per Cent. of the Moist Coal. Per Cent. of the Dry Coal. Per Cent, of the Combustible. Moisture 10 Volatile matter 30 33.33 37.50 Fixed carbon 50 55.56 62.50 Ash 10 11.11 Total 100 100.00 100.00 STEAM. A calculation of the power that coal possesses, compared with the useful work which steam engines exert, shows that probably in the very best engines not one-tenth of the power is converted into useful work, and in some very bad engines, probably not one one-hundredth. There are many causes for this; some we can never remedy, because to do so it would be necessary to exhaust the steam at a lower temperature than is practical. There are other causes that can and ought to be removed. We want good engines, good boilers, high-pressure steam, expansive working, and con- densing appliances. High-Pressure Steam.— Why should we use high-pressure steam? There are several good reasons. Whatever pressure we have available at the steam boiler, a certain amount is absorbed in overcoming the resistances of the engine and without doing any useful work. Suppose our available steam pressure is 20 lb., and 10 lb. are so absorbed; that leaves us only one-half; but, if we have 100 lb. available, it would leave us nine-tenths. High-pressure steam means fewer boilers and smaller engines, with founda- tions and houses of less dimensions. Then, again, the amount of work that it is possible to get out of a given quantity of steam depends on the differ- ence between the temperature at the commencement of the stroke and the temperature at the end of the stroke. Now, there is a limit as to how low the temperature can be at the end, and as we raise the commencing temperature, we enlarge the available difference. We may put the advantages of high-pressure steam in this way. By taking a fixed temperature in the condenser of, say, 100° F., and initial temperatures when the steam enters the cylinder, of varying amounts, the theoretic efficiency of that steam can be determined. Commencing with atmospheric pressure, we have an efficiency of 16.6$. Lb. Per Cent. 10 20.0 20 22.1 30 23.7 40 25.0 50 26.1 60 27 .0 §0 28.6 Lb. Per Cent 100 29.8 125 31.1 150 32.2 200 33.9 250 35.3 300 36.5 176 BOILERS. Wp oan only get in practice with steam a certain proportion of the theoretic power, and that proportion varies with the pressure of the steam. In early days we used steam at atmospheric pressure, the efficiency hpinp - 16 6 afterwards, we had, in compound engines of two cylinders, steam of^Olb., the efficiency being 27/*. we have^ ^ pnp-irips usine* stG&in £it 150 lb., ttiG GflticiGiicy being 32.2,0. It observed that although the efficiency increases as the steam pressure increases the amount of that increase is a diminishing quantity, and it becomes so small at and beyond 150 lb. pressure that probably any gain m efficiency is not a satisfactory set-off to the additional expense of strength- eSng the parts of the engine. But then, how very few of our engines work n6 ¥he advantages^ high-pressure steam are not yet sufficiently appreciated. Tt S not meVelf t he difference between 60 lb. and 120 lb. Suppose we use steam at 60 lb.f probably we shall get 50 lb. at engine, and ^sirtances of enHne will absorb 10 lb., leaving 40 lb. Now, suppose we use 120 lb., we can gefat engine 110 lb., and if resistances of engine absorb 10 lb., we shall have 100 EKoan S s ro? l ofsu 0 am.-By “ expansion of steam ” we mean that at a certain noint of the stroke we shut off steam supply from the boiler to the Irnrl the steam already within the cylinder performs the remainder of the s^ok^un^ded aiI ^h)W, Suppose we do not expand at all. Suppose we allow fee ^^dmitsion' of steam into the cylinder all through the stroke; we shall have at the end of the stroke pressure exactly similar to the Pressure with which we commenced. Now, we cannot work a seam of coal and smi nave the coal left* we cannot get work out of steam and still have the work left in it and so’, if our steam pressure is the same at the end of the stroke as at the beginning, we simply discharge twice m each revolution a whole cylinder full of steam that has done no work at all, and waste it just the same as if we had discharged it from the boiler without passing through the SStafat aTl? But some one mil say, work has been done upon the engine while that steam was in the cylinder. True — and the explanation is, that while the steam is performing work its heat and pressure must dimmish, and so long as the communication with the boiler is open, fresh heat comes from the boiler into the cylinder to take its place, and at the end of the strcSe we have expended heat represented by the capacity of two cylinders, and have performed work as represented by the capacity of one cylinder. Nffw suppose we close the communication, and beyond a certain point of the stroke allow no more steam to enter, we get an amount of work from the steam already in the cylinder, represented by the diminishing pressure ° f Condensers —The Effective power of an engine does not depend on, and is not measured by, the pressure pushing the piston. There] is termed a back pressure holding the piston back, and the real effective nressure is evidently the difference between the two. Suppose we have a locomotive engine, or a winding engine, throwing exhaust into the open air The back pressure cannot be less than the pressure of the open air, and indeed to overcome it, it must be something more. But if we can d?scha?ge our exhaust into some vessel from which atmospheric pressure and all^ other pressure has been removed, we ku°w “ e amounts to about 15 lb., and the removal of that from the front of the piston is as good as adding 15 lb. behind. BOILERS. The steam boiler that will be the most suitable for a certain mine will denend on the nature of the feedwater, the cost of fuel, and the amount of steam required. When the acid water from the mine is used for feedwater, and^uel is cheap the type of boiler generally used is either the plain rvllndrical or flue boiled because it is simple in construction and can therefore be easily cleaned and cheaply replaced when eaten by the mine water The tubular or locomotive type is used where good water can be offiffined 1 except in the best equipped plants, where the water-tube boiler is used Feedwater taken from the mine, or containing acid, should be neutralized by lime or soda before being used. In case it contains minerals fn solution, a feedwater separator should be employed to Precipitate the mineral substance before the water is allowed to enter the boiler. HORSEPOWER OF BOILERS. 177 We always calculate the strength of a boiler in the direction of its diameter, because, theoretically, a boiler is twice as strong in the direction of length as direction of diameter. Many causes may bring about boiler explosions. First, bad materials; second, bad workmanship; third, bad water, which eats away the plates by internal corrosion; fourth, water lying upon plates, bringing about external corrosion; fifth, overpressure: sixth, safety valves sticking; seventh, water getting too low; eighth, excessive tiring; ninth, hot gases acting on plates above water level; tenth, choking of feedpipes; eleventh, insufficient provision for expansion and contraction: twelfth, insufficient steam room and too sudden a withdrawal of a large quantity of steam; thirteenth, getting up steam, or knocking off a boiler too suddenly; fourteenth, allowing wet ashes to lie in contact with plates. The probable causes suggest their several remedies. Wherever possible and except under certain circumstances, stear^ engines should not be placed in the mine, and certainly steam boilers should be in all cases placed upon the surface. Steam injures the ventiia* tion, increasing the temperature where already too high, doing injury and causing inconvenience by condensation, and many tires in mines have been caused by underground boilers. The Lancashire Boiler.— The colliery boiler that finds much fa^or m Eng- land is that class of Lancashire boiler which is 28 or 30 ft. long ana 7 or 8 ft. in diameter, and has two large flues running through. There is no doubt that the marine type will generate more steam with a given amount of coal, and, consequently, is gaining ground, and will gain grouna where coal is dear. But the Lancashire boiler is a good steam generator, and will not only work longer without repairs, but is less troublesome and expensive to repair. The favorite construction some few years ago was wrought iron with double-riveted horizontal joints and Galloway tubes (Galloway tubes are simply taper tubes running across the flues in the boiler), and expansion weldless hoops strengthening the flues and allowing for expan- sion and contraction. The dimensions were 7 ft. diameter, and from 28 to 30 ft. long, with internal flues each 2 ft. 9 in. diameter, the circular plates being about i in. and the end plates about f in. The safe working pressure was about 60 lb. per sq. in. Now the conditions are somewhat altered. Steel has taken the place of iron, giving increased strength, and allowing increased diameter and increased pressure. Ring plates have also abolished a great source of weakness in a boiler, namely, horizontally riveted joints. A good Lancashire boiler now will measure 8 ft. in diameter and 30 ft. long, with ring plates f in. thick, end plates probably £ in., and will work very well at 120 lb. pressure per sq. in. Horsepower of Boilers.— The horsepower of a boiler is a measure of its capacity for generating steam. Boilermakers usually rate the horsepower of their boilers as a certain fraction of the heating surface; but this is a very indefinite method, for with the same heating surface, different boilers of the same type may, under different circumstances, generate different quantities of steam. In order to have an accurate standard of boiler power, the American Society of Mechanical Engineers has adopted as a standard horsepower an evaporation of 30 lb. of water per hour from a feedwater temperature of 100° F. into steam at 70 lb. gauge pressure , which is considered equivalent to 34.5 units of evaporation; that is, to 34.5 lb. of water evaporated from a feedwater temperature of 212° F. into steam at the same temperature. Example.— A boiler evaporates per hour 1,980 lb. of water from a feed temperature of 100° into steam at 70 lb. gauge pressure. What is the horsepower of the boiler? Since, under the given conditions, an evaporation of 30 lb. is equivalent to 1 horsepower, the number of horsepower is 1,980 -r- 30 = 66. In the various types of boilers there is a nearly constant ratio between the water-heating surface and the horsepower, and also between the heating surface and the grate area. These ratios are given in the table on page 178. If the heating surface of a boiler is known, the horsepower can be found roughly; thus, if a return-tubular boiler has a heating surface of 900 sq. ft., its horsepower lies between - 9 T ° g °- = 50 H. P. and 9 X ° 5 °- = 64.3 H. P., say about 57 H. P. The heating surface of a boiler is the portion of the surface exposed to the action of flames and hot gases. This includes, in the case of the multi- tubular boiler, the portions of the shell below the line of brickwork, the exposed heads of the shell, and the interior surface of the tubes. In the 178 BOILERS. case of a water-tube boiler, the heating surface comprises the portion ol the shell below the brickwork, the outer surface of the headers, and outer surface of tubes. In any given case, the heating surface may be calculated Ratio of Heating Surface to Horsepower and of Heating Surface to Grate Area. Type of Boiler. _ A ._ Heating Surface Ratio — Horsepower Heating Surface Ratio - Grate Area Plain cylindrical Elue 6 to 10 8 to 12 12 to 15 20 to 25 Return - tubular V ertical 14 to 18 15 to 20 25 to 35 25 to 30 Water-tube Locomotive 10 to 12 1 to 2 35 to 40 50 to 100 bv the rules of mensuration, rne ionowmg ewimuc nf calculating the heating surface of a return-tubular boiler. Example — A horizontal return-tubular boiler has the followmg dimen- sion Diameter 60 in.; length of tubes, 12 ft.; internal diameter of tubes^ 3 iS number of tubes ’ 82. Assume that f of the shell is in contact with hnt or flame and f of the two heads are heating surface. _ . S fH ' ofshe11 - - m5in " say ' . Heating surface of tubes = v* TOM - 4 2827 44 sq^n. ^ Area of one head — ® X ™ h = V7fiq'92 sa in the d helds mu^t be sSbtracted\wice the area cut out by the tubes; this is 82 X 32 X .7854 X 2. = 1,159.26. Total heating surface m square feet — 18,096 + 111,290.4 + 3,769.92-1,159.26 144 = 916.64 sq.ft. Ans. Pporarle Maximum Work of a Plain Cylindrical Boiler of 120 Sq.Ft. ^ ^HeaSw” Bubfacb and 12 Sq. Ft. Gbate Surface, at Different Rates of Driving. Rate of driving; lb. water evaporated | per sq. ft. of heating surface per hour .... 2 3 3.5 4 4.5 5 6 7 8 Total water evapora- ted by 120 sq. ft. heating surface peri hour lb 240.00 360.00 420.00; o © oB 540.00 600.00 720.00 840.00 960.00 Horsepower; 34.5 lb. per hour = 1 H. P. 6.96 10.43 12.17 13.91 1 15.65 1 17.39 20.87 24.35 27.83 Pounds water evapo- rated per lb. com- V^nctihlp 10.88 11.30 11.36 11.29 11.20 11.05 10.48 9.48 i 8.22 Uuoiiuiv ? Pounds combustible burned per hour ... 22.10 31.90 37.00 42.50 48.20 54.30 68.70 88.60 116.80 Pounds combustible per hour per sq.ft. nf OTQt.P 1.85 2.65 3.08 3.55 4.02 4.52 5.72 7.38 9.73 Pounds combustible per hour per horse- 3.17 3.05 i 3.04 3.06 3.08 ; 3.12 3.30 i 3.64 4.16 pu w 1 urAm fhh fi mires in the last line, we see that the amount of fuel required for^given horsepower is nearly 37^ greater when the rate of evaporation is 8 lb. Sian when it is 3-5 lb. DANGER OF EXPLOSION. 179 The figures in the preceding table that represent the economy of fuel, viz., “Pounds water evaporated per lb. combustible” and “Pounds combustible per hour per horsepower,” are what may be called “maximum” results, and they are the highest that are likely to be obtained with anthracite coal, with the most skilful tiring and with every other condition most favorable. Unfavorable conditions, such as poor tiring, scale on the inside of the heating surface, dust or soot on the outside, imperfect protection of the top of the boiler from radiation, leaks of air through the brickwork, or leaks of water through the blow-off pipe, may greatly reduce these figures. Choice of a Boiler.— Questions that arise under this head in regard to any boiler are: 1. Is the grate surface sufficient for burning the maximum quantity of coal expected to be used at any time, taking into consideration the availa- ble draft, the quality of the coal, its percentage of ash, whether or not the ash tends to run into clinker, and the facilities, such as shaking grates, for getting rid of the ash or clinker? 2. Is the furnace of a kind adapted to burn the particular kind of coal used? 3. Is the heating surface of extent sufficient to absorb so much of the heat generated that the gases escaping into the chimney shall be reasonably low in temperature, say not over 450° F. with anthracite, and 550° F. with bituminous coal? 4. Are the gas passages so designed and arranged as to compel the gas to traverse at a uniform rate the whole of the heating surface, being not so large at any point as to allow of the gas finding a path of least resistance, or short-circuiting, or, on the other hand, so contracted at any point as to cause an obstruction to the draft? These questions being settled in favor of any given boiler — and they may be answered favorably for boilers of many of the common types — the relative merits of the different types may now be considered with reference to their danger of explosion; their probable durability; the character and extent of repairs that may be needed from time to time, and the difficulty, delay, and expense that these may entail; the accessibility of every part of the boiler to inspection, internal and external; the facility for removal of mud and scale from every portion of the inner surface, and of dust and soot from the exterior; the water and steam capacity; the steadiness of water level, and the arrangements for securing dry steam. Each one of the points referred to above should be considered carefully by the intending purchaser of any type of boiler with which he is not familiar by experience. The several points may be considered more in detail. Danger of Explosion.— All boilers may be exploded by overpressure, such as might be caused by the combination of an inattentive fireman and an inoperative safety valve, or by corrosion weakening the boiler to such an extent as to make it unable to resist the regular working pressure; but some boilers are much more liable to explosion than others. In consider- ing the probability of explosion of any boiler of recent design, it is well to study it to discover whether or not it has any of the features that are known to be dangerous in the plain cylinder, the horizontal tubular, the vertical tubular, and the locomotive boilers. The plain cylinder boiler is liable to explosion from strains induced by its method of suspension, and by changes of temperature. Alternate expansion and contraction may produce a line of weakness in one of the rings, which may finally cause an explosion. A boiler should be so suspended that all its parts are free to change their posi- tion under changes of temperature without straining any part. The circulation of water in the boiler should be sufficient to keep all parts at nearly the same temperature. Cold ffiedwater should not be allowed to come in contact with the shell, as this will cause contraction and strain. The horizontal tubular boiler, and all externally-fired shell boilers, are liable to explosion from overheating of the shell, due to accumulation of mud, scale, or grease, on the portion of the shell lying directly over the fire, to a double thickness of iron with rivets, together with some scale, over the fire, or to low water uncovering and exposing an unriveted part of the shell directly to the hot gases. Vertical tubular boilers are liable to explosion from deposit of mud, scale, or grease, upon the lower tube-sheet, and from low Water allowing the upper part of the tubes to get hot and cease to act as stays to the upper tube-sheet. Locomotive boilers may explode from deposits On the crown sheet, from low water exposing the dry crown sheet 180 BOILERS. to the hot gases, and from corrosion of the staybolts. Double-cylinder boilers, such as the French elephant boiler, and the boilers used at some American blast furnaces, have exploded on account of the formation oi a “steam pocket” on the upper portion of the lower drum, the steam being prevented from escaping from out of the rings of the drum by the lap joint of the adjoining ring, thus making a layer of steam about 4 inch micx against the shell, which was directly exposed to the hot gases. Questions to Be Asked Concerning New Boilers. — The causes mentioned above are only a few of the causes of explosions, but they are the principal ones that are due to features of design. These features should be looked for in any new style of boiler, and if they are found they should be considered elements of danger. Such questions as the following may be asked: is tne method of suspension of the boiler such as to allow its parts to be tree to move under changes of temperature? Is the circulation such as to keep all parts at practically the same temperature? Is there a shell with Riveted seams exposed to the fire? Is there a shell exposed to the hre that may at any time be uncovered by water? Is there a crown sheet on which scale mav lodge? Are there vertical or inclined tubes acting as stays to an upper sheet, the upper part of which tubes may become overheated m case 01 low water? Are there any stayed sheets, the stays of which are liable to become corroded? Is there any chance for a steam pocket to be formed on a sheet that is exposed to the fire? _ _ , . , . In addition to the above-mentioned features of design, which are elements of danger, all boilers, as already stated, are liable to corrosion. Internal corrosion is usually due to acid feedwater, and all boilers are equally liable to it. External corrosion, however, is more liable to take place in some designs of boilers than others, and m rather than others. If any portion of a boiler is in a cold and damp place, it is liable to rust out. For this reason the mud-drums of many modern forms of boilers are made of cast iron, and resist rusting better than either wrought iron or steel. If any part of a boiler, other than a part made of cast iron is liable to be exposed to a cold and damp atmosphere, or covered with damp or ashes or exposed to drip from ram or from leaky pipes, and especially if such part is hidden by brickwork or otherwise so that it can- “,:as sasssa ssss: », w . x 3—ed by interi or external corrosion, but they may also be burned nut It mav “i e ded ag imposs ible to burn a plate or tube of iron or rin matter how high the temperature of the flame, provided one side of ft* Staffs ^cove?S with water. If a steam pocket is formed, so that the wntS does not* touch the metal, or if there is a layer of grease or hard scale thpn the nlate or tube may be burned. In a water tube that is horizontal, o ^trlv so and in which the circulation of water is defective, it is Possible to nearly so, anu , . m drive the water away from the metal, and fallow the tabe to ^ burn out In considering the probable durability of a Soiler we may ask the same questions as those that have been asked dimeer of explosion. There are, however, many chances of Wntn^ out a mfnor part of a boiler without serious danger, to one chance nf ^difastrous explomon. Thus the tubes of a water-tube boiler, if allowed £ thicklvcovered with scale, might be burned out again and again without causing ^any further destruction at any one time than the rupture Tnew type of boiler should be questioned in regard to the u 4 ohhnod of frequent small repairs being necessary, as well as in regard to likelihood ot irequein ^ P We ^ gk; Is the circulation through all rnr’ S \he ta er s4h Sarthe water cannot be driven out of any tube anv nortion of a plate, so as to form a steam pocket exposed to high temperature? 0 Are thereproper facilities for removing the scale from every P° oin?i« th Thiquts a t?ons U of e dL and of repairs are, in some respects, ,*•£1 "to 7a ch other The more infrequent and the less extensive the relat >^ tb p 6 ffreater the durability. The tubes of a boiler, where corroded or ™P a JZv bt replaced and made as good as new. The shell, when it burnt out, may P tched an( j i s then likely to be far from as good as springs a leak, y P d badlv it must be replaced, and to replace the new . When ^the ^shel oau Herei ^ is the advantage of the seclional wX-Ue toilerl The sections, or parts of a section, may be WATER AND STEAM CAPACITY. 181 renewed easily, and made as good as new while the shell being far reared from the fire and easily kept dry externally, is: H J out or external corrosion. In considering .the merits o a new; style ol boiler with reference to repairs, we may ask what parts ot tne Doner are most likelv to give out and need to be repaired or replaced? Are these repairs easily effected, how long will they require, and, after they are made, iS t F* e eHU» e fof Removal ofYcale and for Inspeotion.-These questions have already lleen discussed to some extent under the head of durability. Some w«t2r-tube boilers now dead and gone, were some years ago put on the market which had no facilities for the removal of scale. It was claimed by SeirproCtersthat they did not need any, because th^utobonwMso raDid Every few years boilers of these types are reinvented, and the same claim is madl for them, that their rapid circulation prevents the formation of scale The fact is that if there is scale-forming material m the water it will be deposited when the water is evaporated, and no amount or kind of circulation will keep it from accumulating on every part of the boiler, jmd in every kind of tubes, vertical, horizontal, and inclined. I have seen the nearly vertical circulating tubes of a water-tube boiler, circulation is nine times as fast as the average circulation m the inclined tubes! nearly full of scale; that is, a 4" tube had an opening m it of less than 1 in in diameter. This was due to carelessness m blowing off the boiler, or exceptionally bad feedwater, or both. If circulation would prevent scaling at Water^nd^tf^CaJadty^-B is claimed for some forms of boilers that they are better than others because they have a larger water or steam capacity. Great water capacity is useful where the demands for steam are extremely fluctuating, as in a rolling mill or a sugar refinery, where it is desirable^to store up heat in the water in the boilers during the periods of the least demand, to be given out during periods of greatest demand. Large water capacity is obiectionable in boilers for factories, usually, especially if ?hev do not run at night, and the boilers are cooled down, because there is a lar Je Quantity of w | te r to be heated before starting each morning. If -mnid steaming” or the ability to get up steam quickly from cold water, or to rSse the pressure quickly, is desired, large water capacity is a. detriment. Thl dSWe steam capacity is usually overrated. It is useful to enable the steam to be drained from water before it escapes into the steam r>i ne but the same result can be effected by means of a dry Pipe, as m fo?omotive and SIrine practice, in which the steam space m the boiler is very small hi proportioS to the horsepower. Large steam space in the io no irrmortance for storing energy or equalizing the pressure ^irinVfhfstrokeXan^ enjine The water in the boiler is the place to store heat and if the steam pipe leading to an engine is of such small capacity that it reduces the pressure, the remedy is a steam reservoir close to the eng St n eldTn«s a oTwate?Te«eL-This requires either a large area of water sur- Steadiness oTwaxer Leve. h slow i y by fluctuations in the demand fofstlam or in the of thffl-pumpT or else constant, and preferably a^itomaUc° regulation 1 of the feedwater supply to suit the steam demand A ranidlv lowering water level is apt to expose dry sheets or tubes to the ^ctfon of thl hot gases, and thus be a source of danger A rapidly rising level may before it is seen by the fireman, cause water to be carried over ° f f^ilfp'boifor 'of a boiler is important for two reasons: (1) To keep all parts of the toiler of a uniform temperature, and (2) to prevent the adhesion of steam bubbles to ihe f SStee whfch may cause overheating of the metal It is claimed by some manufacturers that the rapid circulation of water m their boilers tends to make them more economical than others. I have as yet, however, to findanv proof that increased rapidity of circulation of water beyond t h at usual 1 v found in any boiler will give increased economy. We know that increased rate of flow of air over radiating surfaces increases the amount of heat transmitted through the surface, but increased circulation, cold air is continually brought into contact with the surface making an increased difference of temperature on the two sides, which causes increased transmission. But by increasing the rapidity oi circulation^ a steam boiler we cannot vary the difference of temperature to any appreciable extent, for the water and the steam in the boiler are at 182 BOILERS . about the same temperature throughout. The ordinary or “Scotch” form of marine boiler shows an exception to the general rule of uniformity of temperature of water throughout the boiler, but the temperature above the level of the lower fire tubes is practically uniform. INCRUSTATION AND SCALE. Nearly all waters contain foreign substances in a greater or less degree, and though this may be a small amount in each gallon, it becomes of importance where large quantities are evaporated. For instance, a 100 H. P. boiler evaporates 30,000 lb. of water in 10 hours, or 390 tons per month; in comparatively pure water there would be 88 lb. of solid matter in that quantity, and in many kinds of spring water as much as 2,000 lb. The nature and hardness of the scale formed of this matter will depend on the kind of substances held in solution and suspension. Analyses of a great variety of incrustations show that carbonate and sulphate of lime form the larger part of all ordinary scale, that from carbonate being soft and granular, and that from sulphate, hard and crystalline. Organic substances in connection with carbonate of lime will also make a hard and troublesome scale. The presence of scale or sediment in a boiler results in loss of fuel, burning and cracking of the boiler, predisposes to explosion, and leads to extensive repairs, it is estimated that the presence of in. of scale causes a loss of 13 $ of fuel; i in., 38^; and ± in., 60$. The Railway Master Mechanics’ Association of the United States estimates that the loss of fuel, extra repairs, etc., due to incrustation, amount to an average of 8750 per annum for every locomotive in the Middle and Western States, and it must be nearly the same for the same power in stationary boilers. Causes of Incrustation.— 1. Deposition of suspended matter. 2. Deposition of salts from concentration. 3. Deposition of carbonates of lime and magnesia, by boiling off carbonic acid, which holds them in solution. 4. Deposition of sulphates of lime, because sulphate of lime is soluble in cold water, less soluble in hot water, insoluble above 270° F. 5. Deposit of magnesia, because magnesium salts decompose at high temperatures. 6. Deposition of lime soap, iron soap, etc., formed by saponification of grease. Method of Preventing Incrustation.— 1. Filtration. 2. Blowing off. 3. Use of internal collecting apparatus, or devices, for directing the circulation. 4. Heating feedwater. 5. Chemical or other treatment of water in boiler. 6. Introduction of zinc in boiler. 7. Chemical treatment of water outside of boiler. Troublesome Substance. Trouble. Remedy or Palliation. Sediment, mud, clay, etc. Readily soluble salts. Bicarbonates of lime, magnesia, and iron. Sulphate of lime. Chloride and sulphate of magnesium. Carbonate of soda in large amounts. Acid (in mine water). Dissolved carbonic acid and oxygen. Incrustation. Incrustation. Incrustation. Incrustation. Corrosion. Priming. Corrosion. Corrosion. Grease (from condensed water). Corrosion. Organic matter (sewage). Priming. Organic matter. Corrosion. Filtration; blowing off. Blowing off. Heating feed; addition of caustic soda, lime, or magnesia, etc. Addition of carbonate of soda, barium chloride, etc. Addition of carbonate soda, etc. Addition of barium chloride, etc. Alkali. , Heating feed; addition of caustic soda, slaked lime, etc. Slaked lime and filtering. Substitute mineral oil. Precipitate with alum or ferric chloride, and filter. Precipitate with alum or ferric chloride, and filter. PREVENTION OF SCALE. 183 Means of Prevention. — It is absolutely essential to the successful use of any boiler except in pure water, that it be accessible for the removal of scale, for though a rapid circulation of water will delay the deposit, and certain chemicals will change its character, yet the most certain cure is Periodical inspection and mechanical cleaning. This may , however, be rendered less frequently necessary, and the use of very bad water more practical bv the employment of some preventives. The following are fair samples ol those in use. with their results: . . , ,, , . . M Bidard’s observations show that “ anti-mcrustators containing organic matter help rather than hinder incrustations, and are therefore t0 Oak hemlock, and other barks and woods, sumac, catechu, logwood, etc. are effective in waters containing carbonates of lime or magnesia, by reason of their tannic acid, but are injurious to the iron and not to be recom- me Mo!asses, cane juice, vinegar, fruits, distillery slops etc. have been used With success so far as scale is concerned, by reason of the acetic acid that they contain, but this is even more injurious to the iron than tannic acid, while the organic matter forms a scale with sulphate of lime when it is Pre MUk of lime and metallic zinc have been used with success in waters charged with bicarbonate of lime, reducing the bicarbonate to the insoluble Ca Barium chloride and milk of lime are said to be used with good effect at Krupp’s works, in Prussia, for waters impregnated with gypsum. Soda ash and other alkalies are very useful in waters containing sulphate of lime bv converting it into a carbonate, and so forming a soft scale easily cleaned. But when used in excess they cause foaming, particularly where there is oil coming from the engine, with which they form soap. All soapv substances are objectionable for the same reason. Petroleum has been much used of late years. It acts best m waters m which sulphate of lime predominates. Sulphate of lime is the injurious Stance in nearly all mine waters, and petroleum when properly prepared, is a good preventive of scale and pitting. Crude petroleum Should not be used, as it sometimes helps in forming a very injurious scale. Refined petroleum, on the other hand, is useless, as it vaporizes at a temperature below that of boiling water. Therefore, only such prepara- tions should be used as will not vaporize below 500° F. Tannate of soda* is a good preparation for general use, but m waters con- taining much sulphate, it should be supplemented by a portion of carbonate of ^rom the leaves of the eucalyptus is found to work well in ^^o^muddy 1 water^^rticularly if it contain salts ? f lime, no preventive of incrustation will prevail except filtration, and in almost every instance the use of a filter, either alone or in connection with some means of precipita- ting the solid matter from solution, will be found very desirable. . ,, In all cases where impure or hard waters are used, frequent blowing from the mud-drum is necessary to carry off the accumulated matter, which if allowed to remain would form scale. ....... When boilers are coated with a hard scale, difficult to remove, it will be found that the addition of i lb. caustic soda per horsepower, and steaming for some hours, according to the thickness of the scale, just before cleaning, will ffreatlv facilitate that operation, rendering the scale soft and loose. This should be done, if possible, when the boilers are not otherwise m use. COVERING FOR BOILERS, STEAM PIPES, ETC. The losses by radiation from unclothed pipes and vessels containing steam are considerable, and in the case of pipes leading to steam engines, are magnified by the action of the condensed water m the cylinder. It there- fore is important that such pipes should be well protected The following table ffives the loss of heat from steam pipes naked, and clothed with wool or hair felt, of different thickness, the steam pressure being assumed at 75 lb., There is a wide difference in the value of different substances for protec- tion from radiation, their values varying nearly in the reverse ratio to their conducting power for heat, up to their ability to transmit as much heat as 184 BOILERS. the surface of the pipe will radiate, after which they become detrimental, rather than useful, as covering. This point is reached nearly at baked clay or brick. Table of Loss of Heat From Steam Pipes. Outside Diameter of Pipe, Without Felt Thickness of Covering. In< 2 In. Diameter. 4 In. Diameter. 6 In. Diameter. 8 In. Diameter. 12 In. Diameter. Loss in Units per Foot Run per Hour. Ratio of Loss. | • 1 Feet in Length per H. P. Lost. Loss in Units per Foot Run per Hour. Ratio of Loss. Feet in Length per H. P. Lost. Loss in Units per Foot Run per Hour. Ratio of Loss. Feet in Length per H. P. Lost. Loss in Units per Foot Run per Hour. Ratio of Loss. Feet in Length per H. P. Lost. Loss in Units per Foot Run per Hour. | Ratio of Loss. Feet in Length per H. P. Lost. 0 219.0 1.00 132 390.8 1.00 75 624.1 1.000 46 729.8 1.000 40 1,077.4 1.000 26 i 100.7 .46 288 180.9 .46 160 i 65.7 .30 441 117.2 .30 247 187.2 .300 154 219.6 .301 132 301.7 -.280 92 ] 43.8 .20 662 73.9 .18 392 111.0 .178 261 128.3 .176 225 185.3 .172 157 2 28.4 .13 1,020 44.7 .11 648 66.2 .106 438 75.2 .103 385 98.0 .091 294 4 19.8 .09 1,464 28.1 .07 1,031 41.2 .066 703 46.0 .063 630 60.3 .056 486 6 23.4 .06 1,238 33.7 .054 860 34.3 .047 845 45.2 .042 642 A smooth or polished surface is of itself a good protection, polished tin or Russia iron having a ratio, for radiation, of 53 to 100 for cast iron. Mere color makes but little difference. Table of Conducting Power of Various Substances. ( From Peclet.) Substance. Conducting Power. Substance. * Conducting Power. Blotting paper .274 Wood, across fiber .83 Eiderdown .314 Cork 1.15 Cotton or Wool, | QOQ Coke, pulverized 1.29 any density j .oZo India rubber 1.37 Hemp, canvas .418 Wood, with fiber 1.40 Mahogany dust .523 Plaster of Paris 3.86 Wood ashes .531 Baked clay 4.83 Straw .563 Glass 6.60 Charcoal powder .636 Stone 13.68 Hair or wool felt has the disadvantage of becoming soon charred from the heat of steam at high pressure, and sometimes of taking fire therefrom. This has led to a variety of “cements” for covering pipes— composed gen- erally of clay mixed with different substances, as asbestos, paper fiber, charcoal, etc. A series of careful experiments, made at the Massachusetts Institute of Technology in 1871, showed the condensation of steam in a pipe covered by one of them, as compared with a naked pipe, and one clothed with hair felt, was 100 for the naked pipe, 67 for the “cement” covering, and 27 for the hair felt. . . . The presence of sulphur in the best coverings and its recognized injurious effects make it imperative that moisture be kept from the coverings, for, if present, it will surely combine with the sulphur, thus making it active. Stated in other words, keep the pipes and coverings in good repair. Much of the inefficiency of coverings is due to the lack of attention given them; they are often seen hanging loosely from the pipe which they are supposed to protect. CARE OF BOILERS. 185 Table of Relative Value of Non-Conductors. ( From Chas. E. Emery, Ph. D.) Non-Conductor. Value. Non-Conductor. Value. Wnnl felt 1.000 Loam, dry and open .550 Mineral wool No 2 .832 Slaked lime .480 lYllllvlcU W wl i’v. ^ Mineral with tar .715 Gas-house carbon .470 1VIII1CI cXA W ini Qo wflnat. .680 Asbestos .363 .345 oaWUUSl Mineral wool No. 1 PViotpaqI .676 .632 f'lnal qkLpk Coke in lumps .277 T)i y-i a q PTOSS fiber .553 Air space undivided .136 JL 111“ W UUU dblvoo AX MUX Carbonate of magnesia, as compared with wool felt at 1.000, has a rela- tive value of 472. This is determined from tests by Prof. Ordway, of Boston, an '^^ ^g, - a ^°^rk°clSps, n cemented C together with water glass, make one of the best eoverin^s known but a very efficient one, may be annlied as ^follows First, wrap the pipe in asbestos paper, though this may be dispenLd wUh; then lay slips of wood lengthways from 6 to 12, accord- ino- to size of pipe, binding them in position with wire or cord, and around the framework thus constructed wrap roofing paper, fastening it bv naste or twine. For flanged pipe, space may be left for access to the bolts which space should be filled with felt. If exposed to weather, use tkrrld naper T paint the exterior. A French plan is to cover the surface with a rough flour paste, mixed with sawdust until it forms a nmderately stiff dough Apply with a trowel in layers of about 4 in. thick, give 4 or 5 layers iifall. If P iron surfaces are well cleaned from grease, the adhesion is perfect. For copper, first apply a hot solution of clay m water. A coating of tar renders the composition impervious to the weather. DATA FOR PROPORTIONING AN ECONOMIZER. ( The Green Fuel Economizer Co., Matteawan, N. Y.) The following estimate is given for the amount of heating surface to be provided in an Iconomizer to be used in connection with a given amount of b01 Bv allowing 4 sq. ft. of heating surface per boiler horsepower (Centennial rating^W lb of water evaporated from and at 212° = I E P.), we are able to raise the feedwater 60° for every 100° reduction m the temperature enter- ing the economizer with gases from 450° to 600°. These results are cor- r ° b WH^?lm^t^p?rature S o?the gases entering the economizer at 600° to 700°, we have allowed 4£ to 5 sq. ft. of heating surface per boiler horsepower, and for every 100° reduction of gases we have obtained about 65 rise m temperature of the water; the temperature of the feedwater entering aver- agl w1thToOO° sq°ft. 2 of ’ boiler heating surface (plain cylinder boilers) develop- ing 1 000 H. P., we should recommend using 5 sq. ft of economizer heating surface per B. H. P., or an economizer of about 500 tubes, and it should heat the feedwater about 300°. CARE OF BOILERS. 1 Safetv Valves —Great care should be exercised to see that these valves are ample in size and in working order. Overloading or neglect frequently leads to the most disastrous results. Safety valves should be tried at least once every day, to see that they act freely. 2 Pressure Gauge.-The steam gauge should stand at zero when the pressure is off, and it should show same pressure as the safety valve when that is blowing off. If not, then one is wrong, and the gauge should be tested by one known to be correct. 186 BOILERS. 3. Water Level.— The first duty of an engineer before starting, or at the beginning of his watch, is to see that the water is at the proper height. Do not rely on glass gauges, floats, or water alarms, but try the gauge-cocks. If they do not agree with water gauge, learn the cause and correct it. 4. Gauge-cocks and water gauges must be kept clean. Water gauges should be blown out frequently, and the glasses and passages to them kept clean. The Manchester, England, Boiler Association attributes more accidents to inattention to water gauges than to all other causes put together. 5. Feed-Pump or Injector. — These should be kept in perfect order, and be of ample size. No make of pump can be expected to be continuously reliable without regular and careful attention. It is always safe to have two means of feeding a boiler. Check-valves and self-acting feed-valves should be frequently examined and cleaned. Satisfy yourself frequently that the valve is acting when the feed-pump is at work. 6. Low Water.— In case of low water, immediately cover the fire with ashes (wet if possible) or any earth that may be at hand. If nothing else is handy, use fresh coal. Draw fire as soon as it can be done without increas- ing the heat. Neither turn on the feed, start nor stop engine, nor lift safety valve until fires are out and the boiler cooled down. 7. Blisters and Cracks.— These are liable to occur in the best plate iron. When the first indication appears, there must be no delay in having it carefully examined and properly cared for. 8. Fusible plugs, when used, must be examined when the boiler is cleaned, and carefully scraped clean on both the water and fire sides, or they are liable not to act. 9. Firing.— Fire evenly and regularly, a little at a time. Moderately thick fires are most economical, but thin firing must be used where the draft is poor. Take care to keep grates evenly covered, and allow no air holes in the fire. Do not “ clean” fires oftener than necessary. With bituminous coal, a “coking fire,” i. e., firing in front and shoving back when coked, gives best results if properly managed. 10. Cleaning.— All heating surfaces must be kept clean outside and in, or there will be a serious waste of fuel. The frequency of cleaning will depend on the nature of fuel and water. When a new feedwater supply is introduced, its effect upon the boiler should be closely observed, as this new supply may be either an advantage or a detriment as compared with the working of the boiler previous to its introduction. As a rule, never allow over T y r scale or soot to collect on surfaces between cleanings. Handholes should be frequently removed and surfaces examined, particularly in case of a new boiler, until proper intervals have been established by experience. The exterior of tubes can be kept clean by the use of blowing pipe and hose through openings provided for that purpose. In using smoky fuel, it is best to occasionally brush the surfaces when steam is off. 11. Hot Feedwater.— Cold water should never be fed into any boiler when it can be avoided, but when necessary it should be caused to mix with the heated water before coming in contact with any portion of the boiler. 12 Foaming.— When foaming occurs in a boiler, checking the outflow of steam will usually stop it. If caused by dirty water, blowing down and pumping up will generally cure it. In cases of violent foaming, check the draft and fires. 13 Air Leaks.— Be sure that all openings for admission of air to boiler or flues, except through the fire, are carefully stopped. This is frequently an unsuspected cause of serious waste. 14 Blowing Off.— If feedwater is muddy or salt, blow off a portion fre- quentlv, according to condition of water. Empty the boiler every week or two and fill up afresh. When surface blow cocks are used, they should be often opened for a few minutes at a time. Make sure no water is escaping from the blow-off cock when it is supposed to be closed. Blow-off cocks and check-valves should b'e examined every time the boiler is cleaned. Never empty the boiler while the brickwork is hot. 15. Leaks.— When leaks are discovered, they should be repaired as soon as possible. 16 Filling Up.— Never pump cold water into a hot boiler. Many times leaks, and, in shell boilers, serious weaknesses, and sometimes explosions are the result of such an action. THICKNESS OF BOILER IRON. 187 \ 17 Dampness.— Take care that no water comes in contact with the exterior of P the boiler from any cause, as it tends to corrode and weaken the boiler. Beware of all dampness in seatmgs and coverings. 18 Galvanic Action.— Examine frequently parts in contact with copper or brass where water is present, for signs of corrosion. If water is salt or acid, some’ metallic zinc placed in the boiler will usually prevent corrosion, but it will need attention and renewal from time to time. , 19 Rapid Firing.— In boilers with thick plates or seams exposed to the fire steam should 8 be raised slowly, and rapid or intense firing avoided. With thin water tubes, however, and adequate water circulation, no dam- ag ^ 0 an stand?ng r Unu sel— If a boiler is not required for some time, empty and dry it thoroughly* If this is impracticable, fill it quite full of water and put in a quantity of common washing soda. External parts exposed to damp- ne ?l S X d a Aould be looked after at least once a vear given necessary repairs, refitted to the pipe, and the spaces due to ffiLfe taken up Little can be expected from the best non-conductors if they are allowed to become saturated with water, or if air-currents are nermitted to circulate between them and the pipe. . i_, vrv f P 22. General Cleanliness.— All things about the boiler room should be kept clean and in good order. Negligence tends to waste and decay. THICKNESS OF BOILER IRON REQUIRED AND PRESSURE ALLOWED BY THE LAWS OF THE UNITED STATES. Pressure Equivalent to the Standard for a Boiler 42 In. in Diam- eter and £ In. Thick. Thickness. 16ths. • 5 4* 4 3» 3£ 3 Diameter. 34 In. Lb. 36 In. Lb. 38 In. Lb. 40 In. Lb. 42 In. Lb. 44 In. Lb. 46 In. Lb. 169.9 158.5 135.9 124.5 113.2 101.9 160.4 149.7 128.3 117.6 106.9 96.2 152.0 141.8 121.6 111.4 101.3 91.2 144.4 134.7 115.5 105.9 96.2 82.6 137.5 128.3 110.0 100.8 91.7 82.5 131.2 122.5 105.0 96.2 87.5 78.7 125.5 117.2 100.0 92.0 83.0 75.1 The rule for finding the proper sectional area for the narrowest part of the nozzle is given by Rankine, S. E., page 477, as follows: cubic feet per hour gross feedwater Area in square inches — 800 V pressure in atmospheres Diameter of Throat. Decimals of an Inch. .10 .15 .20 .25 .30 Delivery in Gallons per Hour with a Pressure per Square Inch of 30 Lb. 45 Lb. 60 Lb. 75 Lb. 56 69 80 89 127 156 180 201 226 278 321 360 354 434 502 561 505 624 722 807 90 Lb. 98 221 393 615 884 188 BOILERS. Pressure of Steam at Different Temperatures. ( Results of Experiments Made by the Franklin Institute.) Pressure. Inches of Mercury. Tempera- ture. Degrees F. Pressure. Inches of Mercury. Tempera- ture. Degrees F. Pressure. Inches of Mercury. Tempera- ture. Degrees F. 30 212.0 135 298.5 225 . 331.0 45 235.0 150 304.5 240 336.0 60 250.0 165 310.0 255 340.5 75 264.0 180 315.5 270 345.0 90 275.0 195 321.0 285 349.0 105 284.0 | 210 326.0 300 352.5 120 291.5 Maximum Economy of Plain Cylinder Boilers. Pounds of Water Evaporated From and at 212°. Per sq. ft. heating surface per hour 1.70 2.00 2.60 3.50 4.00 4.50 5.00 6.00 7.00 8.00 Per lb. combustible, maximum of other boilers, Centennial tests 11.90 12.00 12.10 12.05 12.00 11.85 11.70 11.50 10.85 9.80 8.50 Subtract extra radia- tion loss for cylin- der boilers 1.32 1.12 .87 .75 .64 .56 .50 .45 .37 .32 .28 Probable maximum per lb. combus- tible, cylinder boilprs 10.58 10.88 11.23 11.30 11.36 i 11.29 11.20 11.05 10.48 9.48 8.22 1 1 ■ Scheme for Boiler Test. 1 Mn mhpr nf t 1 o Mn/lp hv Z Q Tvnp nf* Vinllpr - O A Tjotp of t,pst, - 1 Rnratinn of t,PSt Hr. O 6 n Dimensions and Proportions. Number of boilers tested In. / Q E/laLllclCi, uuiici -------- Ft. In. O Q Ft. In. V in T.PnO’th orrc itP Ft. In. 1U JUCllgUl) g 1 No. 1 9 T^iorYidtpr nf tllhps In. 1Z IQ Ft. In. lo 1 A T'rfctcil wqIpt 1 Y \ pn t i n p* siirfn op Sq. Ft. 1 Utdl Wdtt/l llucttiiig Tnfol ctoom liPQtiTiO' cn T*"fVl PP Sq. Ft. Sq. Ft. * 1> ID 1 A 1 Utdl otCdlll DUlldvv turfopp t\ot hnilpp lo 1 7 Ijrldtv 0 U .1 idCv uui 1 vi Par norit air C'AQPP 1TI OTQtp 1 / 18 1 Q it/l belli, dll opdbe 111 gicite Ratio water heating to grate surface - Sq. Ft. on Ft. ZU 21 09 ilGlglll SlaUi. dUUYc UedU piaieo Ratio stack area to grate surface - Average Pressures. A irw aotvVi orn Taxt Kq vayyi ptpp In. zz 9Q A Lino s pile i c uy udi uiiiei^i GtooTYi nroccnrh hv o*Q 11 o*P - Lb. Zo OXalll pieooUlG uy gdUge 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 45 46 47 48 49 50 CHIMNEYS. Scheme for Boiler Test— ( Continued). Force chimney draft, inches water Force blast in ash pit, inches water •--- Average Temperatures. Of external air Oftireroom Of steam Of feedwater before heater Of feedwater after heater Of stack gases •• •••: Fuel. Kind of coal Total coal consumed Moisture in coal Total dry coal consumed - Total ash and refuse - Per cent, ash and refuse in dry coal Total combustible consumed - Calorimetric Tests. Per cent, moisture in steam Degrees superheat in steam "Water . Total water pumped into boiler ----- Water evaporated corrected for quality of steam Equiv. water evap. to dry steam from and at 212 - Equiv. water evap. to dry steam from and at 212° per hour Economic Evaporation. Water evap. per lb. dry coal actual pressures and temp Equiv. water evap. lb. dry coal from and at 212 Equiv. water evap. lb. combustible from and at 212 Rate of Combustion. Dry coal burned per hr. per sq. ft. grate surface Combustible burned per hr. per sq. ft. grate surface Dry coal per hour per H. P. developed Rate of Evaporation. Water evap. from and f Per sq. ft. grate surface at 212° per hour j Per sq. ft. heating surface Commercial Horsepower. Basis 20 lb. water from 100° feed to 70 lb. steam per hour.... Horsepower builders rating - - Heating surface to one horsepower developed Per cent, total horsepower d ^e to feed heater 189 \ In. In. °F. °f" °F. °f’ °F. °f! Lb. Lb. Lb. i Lb. °F. Lb. Lb. Lb. Lb. Lb. Lb. Lb. Lb. Lb. Lb. Lb. Lb. H. P. H. P. Sq. It. ]o CHIMNEYS. Chimneys have two important duties to perform, the first being to carry off the waste furnace gases, which requires size, and the second to produce a draft sufficient to insure the complete combustion of the ^uei, which requires height. The area of a chimney is usually made from - f to is as large as the area of the furnace grates, or of about the same cross-section as the cross-sectional area of the flues or tubes; we have, therefore ^ a c omparaUvely simple method of determining one of the required dimensioi^ of a ch^ and, when this is known, it becomes an easy matter to determine the height of the chimney when the horsepower of the boiler has been ascertained. The horsepower of a boiler being given and the necessary chimney area having been determined, the following rule gives the required height that the chimney must be to produce the necessary draft: , Rule —From 3.33 times the area of the chimney in square feet, subtract twice the rxfvho nron nffhfi nbim/npn in. Ran, are feet, and divide the given horsepower Ru | e —From 3.33 times the area oj me chimney in squuicjv », square root of the area of the chimney in square feet, and divide the given hoi sepower by the remainder. The square of the quotient will be the height of the chimney in feet. A — area of chimney; horsepower of boil height of chimney / x— Jy \3.33 A — 2]/ A/ Then, 190 STEAM ENGINES. Example. — What must be the height of a chimney that is to have a cross- sectional area of 7 sq. ft., and to supply the draft for a 141-horsepower boiler? h = \3.33 X 7 — 2]/ 7 ) = - (.3.33 X 7 - (2 X 2.65 ) ) = 613 ft AnS - Forced Draft.— The use of forced draft as a substitute for, or as an aid to, natural chimney draft is becoming quite common in large boiler plants. Its advantages are that it enables a boiler to be driven to its maximum capacity to meet emergencies without reference to the state of the weather or to the character of the coal; that the draft is independent of the tempera- ture of the chimney gases, and that therefore lower flue temperatures may be used than with natural draft; and in many cases that it enables a poorer quality of coal to be used than is required with natural draft. Forced draft may be obtained: First, by a steam jet in the chimney, as in locomotives and steam fire-engines; second, by a steam-jet blower under the grate bars; third, by a fan blower delivering air under the grate bars, the ash-pit doors being closed; fourth, by a fan blower delivering air into a closed fireroom, as in the “ closed stoke-hold ” system used in some ocean-going vessels; and fifth, by a fan placed in the flue or chimney drawing the gases of combustion from the boilers, commonly called the induced-draft system. Which one of these several systems should be adopted in any special case will usually depend on local conditions. The steam jet has the advantage of lightness and compactness of apparatus, and is therefore most suitable for locomotives and steam fire-engines, but it also is the most wasteful of steam, and there- fore should not be used when one of the fan-blower systems is available, except for occasional or temporary use, or when very cheap fuel, such as anthracite culm at the coal mines, is used. STEAM ENGINES. What Is a Good Steam Engine?— It should be as direct acting as possible; that is, the connecting parts between the piston and the crank-shaft should be few in number, as each part wastes some power. Formerly, beam engines were all the rage. They were well enough in their time for pump- ing, when the pump was at one end of the beam and the piston at the other. Few of our modern colliery engines have such an appendage, except in some instances for pumping, and even for that kind of work the better engines have no beams. The moving parts of an engine should be strong, to resist strains, and light, so as to offer no undue resistance to motion; parts moving upon each other should be well and truly and smoothly finished, to reduce resistances to a minimum; the steam should get into the cylinder easily at the proper time, and the exhaust should leave the cylinder as exactly and as easily. The steam pipes supplying steam should have an area one-tenth the combined areas of the cylinders they supply, and exhaust pipes should be somewhat larger. The cylinder and the steam pipes and the boiler should be well protected. The engine should be capable of being started and stopped and reversed easily and quickly. Rule. — To find the indicated horsepower developed by an engine , multiply together the M. E. P. per square inch , the area of the piston, the length of stroke, and the number of strokes per minute. This gives the work per minute in foot- pounds. Divide the product by 33,000; the result wiU be the indicated horse- power of the engine. Let I. H. P. = indicated horsepower of engine; P = M. E. P. in pounds per square inch; A = area of piston in square inches; L = length of stroke in feet; N = number of strokes per minute. Then, the above rule may be expressed thus: I. H. P. = PLAN 33,000 * The number of strokes per minute is twice the number of revolutions per minute. For example, if an engine runs at a speed of 210 revolutions per minute, it makes 420 strokes per minute. A few types of engines, however, are single acting; that is, the steam acts on only one side of the piston. In this case, only 1 stroke per revolution does work, and, consequently, the RULES FOR ENGINE DRIVERS. 191 number of strokes per minute to be used in the above rule is the same as the number of revolutions per minute. . Example— The diameter of the piston of an engine is 10 in. and the length of stroke 15 in. It makes 250 revolutions per minute, with a M. E. P. of 40 lb ner sa in. What is the horsepower? f As it £ not stated whether the engine is single or double acting, assume that it is double acting. Then, the number of strokes is 250 X 2 — 500 per minute. Hence, I. H. P. = PLAN 40 X if X (10^ X .7854) X 500 = 59.5 H. P. 33,000 33,000 Approximate Determination of M. E. P.-To approximately determine the M. E. P. of an engine, when the point of apparent cut-off is known and the boiler pressure, or the pressure per square inch m the boiler from which the supplv of steam is obtained, is given: . , .. . Rule.— Add U.7 to the gauge pressure, and multiply the result by the number ovvosite the fraction indicating the point of cut-off in the following table. Subtract 17 from the product , and multiply by .9. The result is the M. E. P. for good , simple non-condensing engines. Or, letting p gauge pressure; k -= a constant (see following table); M. E. P. = mean effective pressure. Then, M. E. P. = .9[k(p 14.7) -17]. Table. Cut-Off. Constant. Cut-Off. Constant. Cut-Off. Constant. b I £ .566 f .771 2 3 .917 .603 .4 .789 .7 .926 .659 £ .847 I .937 .3 .708 .6 .895 .8 .944 h .743 5 5 .904 7 5 .951 If the engine is a simple condensing one, subtract the pressure in the condenser instead of 17. * The fraction indicating the point of cut-off is obtained by dividing the distance that the piston has. traveled when the steam is cut off by the whole length of the stroke. For a f cut-off, and 92 lb. gauge pressure in the boiler, the M. E. P. is, by the formula just given, .9 [.917(92 4- 14.7) — 17] = 72.6 lb. per sq. in. a . . Example.— Find the approximate 1. H. P. of a 9" X 12" non-condensmg engine, cutting off at £ stroke, and making 240 revolutions per minute. The boiler pressure is 80 lb. gauge. 7 _ ... 80 4- 14.7 = 94.7. The constant for £ cut-off is .847, and .847 X boiler pressure = .847 X 94.7 = 80.21. M. E. P. = (80.21 - 17) X .9 = 56.89 lb. per sq. in. Then, P L A N _ 56.89 X if X (.7854 X 9 2 ) X 240 X 2 33,000 _ 33,000 52.64 H. P. Ans. RULES FOR ENGINE DRIVERS. If a gauge glass breaks, turn off the water first and then the steam, to avoid scalding yourself. Don’t buy oil or waste simply because it is very cheap; it will cost more than a good article in the end. 192 STEAM ENGINES. In cutting rubber for gaskets, etc., have a dish of water handy, and keep wetting the knife blade; it makes the work much easier. Don’t forget that there is no economy in employing a poor fireman. He can, and probably will, waste more coal than would pay the wages of a first- class man. An ordinary steam engine having two cylinders connected at right angles on the same shaft consumes one-third more steam than a single-cylinder engine, while developing only the same amount of power. A fusible plug ought to be renewed every three months, bv removing the old metal and refilling the case; and it should be scraped clean and bright on both ends every time that the boiler is washed out, to keep it in good working order. When you try a gauge-cock, don’t jerk it open suddenly, for if the water happens to be a trifle below the cock, the sudden relief from pressure at that point may cause it to lift and flow out, deceiving you in regard to its height. Whereas, if you open it quietly, no lift will occur, and you ascertain surely whether there is water or steam at that level. Always open steam stop-valves between boilers very gently, that they may heat and expand gradually. By suddenly turning on steam a stop- valve chest was burst, due to the expansive power of heat unequally applied. The same care is also recommended when shutting off stop- valves. A fearful explosion once occurred by shutting a communicating stop-valve too suddenly— due to the recoil. In order to obtain the driest possible steam from a boiler, there should be an internal perforated pipe (dry pipe, so called) fixed near the top of the boiler, and suitably connected to the steam pipe. The perforations in this pipe should be from one-quarter to one-half greater in area than that of the steam pipe. Domes are of no use as steam driers; they only add a very little to the steam space of a boiler, and are often a source of loss by radiation. if a glass gauge tube is too long, take a triangular file ana wet, 11 with turpentine; hold the tube in the left hand, with the thumb and forefinger at the place where you wish to cut it, saw it quickly and lightly two or three times with the edge of the file, and it will mark the glass. Now take the tube in both hands, both thumbs being on the side opposite the mark, and an inch or so apart, and then try to bend the glass, using your thumbs as ful crums, and it will break at the mark, w r hich has weakened the tube. A stiff charge of coal all over a furnace will lower the temperature 200° or 300° in a very short time. After the coal is well ignited the temperature will rise about 500°, and as it continues burning will gradually drop about 200°, until the fireman puts in another charge, when the sudden fall before mentioned takes place again. This sudden contraction and expansion frequently causes the bursting of a boiler, and it is for this reason that light and frequent charges of coal, or else firing only one-half of the furnace at a time, should be always insisted on. Be careful when using a wrench on hexagonal nuts that it fits snugly, or the edges of the nut will soon become rounded. Be careful how you use a monkeywrench, for if it is not placed on the nut properly the strain will often bend or fracture the wrench. The area of grate for a boiler should never be less than | sq. ft. per I. H. P. of the engine, and it is seldom advisable to increase this allowance beyond I sq . ft. per I. H. P. The area of tube surface for a boiler should not be less than 2£ sq. ft. per I. H. P. of the engine. The ratio of heating surface to grate area in a boiler should be 30 to 1 as a minimum, and may often be increased to 40 to 1, or even more, with advantage. Lap-welded pipe of the same rated size has always the same outside diameter, whether common, extra, or double extra, but the internal diame- ter is of course decreased with the increased thickness. A good cement for steam and water joints is made by taking 10 parts, by weight, of white lead, 3 parts of black oxide of manganese, 1 part of litharge, and mixing them to the proper consistency with boiled linseed oil. To harden a cutting tool, heat it in a coke fire to a blood-red heat and plunge it into a solution of salt and water (1 lb. of salt to 1 gal. of water), then polish the tool, heat it over gas, or otherwise, until a dark straw and purple mixed color shows on the polish, and cool it in the salt water. Small articles can be plated with brass by dipping them in a solution of 9£ gr. each of sulphate of copper and chloride of tin, in If pt. of water. BELTING AND VELOCITY OF PULLEYS. 193 Don’t be eternally tinkering about your engine, but let well enough al °Don’t forget that with a copper hammer you can drive a key just as well as with a steel one, and that it doesn’t leave any marks. Keep on hand slips of thin sheet copper, brass, and tin, to use as liners, and if you shape some of them properly, much time will be saved when you net A few wooden skewer pins, such as butchers use, are very useful for many purposes in an engine room. Try them. . . , In running a line of steam pipe where there are certain rigid points, make arrangements for expansion on the line between those points, or you will come to grief. ' „ , , . , Arrange the usual work of the engine and firerooms systematically, and adhere to it. It pays well. Don’t forget that cleanliness is next to godliness. , ._ Rubber cloth kept on hand for joints should be rolled up and laid away by itself, as any oil or grease coming in contact with it will cause it to soften aiid give out when put to use. , When using a jet condenser, let the engine make three or four revolutions before opening the injection valve, and then open it gradually, letting the engine make several more revolutions before it is opened to the full amount reuuired. * Open the main stop-valve before you start the fires under the boilers. When starting fires, don’t forget to close the gauge-cocks and safety valve as soon as steam begins to form. . An old "Turkish towel, cut in two lengthwise, is better than cotton waste for cleaning brass work. , Always connect your steam valves m such a manner that the valve closes against the constant steam pressure. , , . - . Turpentine well mixed with black varnish makes a good coating for iron smoke T)it)6S Ordinary lubricating oils are not suitable for use in preventing rust. You can make a hole through glass by covering it with a thm coating of wax, warming the glass and spreading the wax on it. Scrape off the wax where you want the hole, and drop a little fluoric acid on the spot with a wire. The acid will cut a hole through the glass, and you can shape the hole with a copper wire covered with oil and rottenstone. A mixture of 1 oz. of sulphate of copper, j oz. of alum, ^ teaspoonful of powdered salt, 1 gill of vinegar and 20 drops of nitric acid will max® a hole in steel that is too hard to cut or file easily. Also, if applied to steel and washed off quickly, it will give the metal a beautiful frosted appearance. BELTING AND VELOCITY OF PULLEYS. Belts should not be made tighter than necessary. Over half the trouble from broken pulleys, hot boxes, etc. can be traced to the fault of tight belts, while the machinery wears much more rapidly than when loose belts are em Thespeed of belts should not be more than 3,000 or 3,750 ft. per minute The motion of driving should run with and not against the laps of the ^Leather belts should be run with the stronger or flesh side on the outside and the grain (hair) side on the inside, nearest the pulley, so that the stronger plirt of the belt may be subject to the least wear. It will also drive 30$ more than if run with the flesh side nearest the pulley. The grain side adheres better because it is smooth. Do not expose leather belts to the We Wh!n the length of a belt cannot be conveniently . ascertained by measuring around the pulleys with a tape line, the following rule will be semceabTe: diameterg of the 2 pulley s together and divide by 2; multiply this quotient by 3i, and to the product add twice the distance between the centers of the shafts; the sum will be the length required. 194 COMPRESSED AIR. COMPRESSED AIR.* By Prof. Robert Peele. An air compressor consists essentially of a cylinder in which atmospheric air is compressed by a piston, the driving power being steam or water. Classification of Compressors.— Steam-driven compressors in ordinary use may be classed as follows: . , , . A , . .. , (a) Straight-line type, in which a single horizontal air cylinder is set tandem with its steam cylinder, and provided with two flywheels. This pattern is generally adapted for compressors of small size. . ( b ) Duplex type, in which there are two steam cylinders, each driving an air cylinder, and coupled at 90° to a crank-shaft carrying a fly wheel. (c) Horizontal , cross-compound engines, each steam cylinder set tandem with an air cylinder, as in (b). . , ( d ) Vertical , simple , or compound engines, with the air cylinders set above the steam cylinders. . . .. , ,, , (e) Compound or stage compressors , m which the air cylinders themselves are compounded. The compression is carried to a certain point in one cylinder and successively raised and finally completed to the desired pres- sure in the others. They may be either of the straight-line or duplex form, with simple or compound steam cylinders. , _ _ Classes (a), ( b ), (c), and (e) are those commonly employed for mine service The principle of compound, or two-srage, air compression is recognized as applicable for even the moderate pressures required in mining, and the compressors of class (e) are frequently employed. Construction of Compressors.— Compressors are usually built with a short stroke as this is conducive to economy in compression as well as the attain- ment of a proper rotative speed. In ordinary single-stage compressors, the usual ratio of length of stroke to diameter of steam cylinders is U to 1 or 1£ to 1. In some makes, such as the Rand, the ratio is considerably greater, varying from H to If to 1, as in several large plants built for the Calumet & Hecla Mining Co. Many compressors have length and diameter of steam cylinders equal. The relative diameters of the air and steam cylinders depend on the steam pressure carried, and the air pressure to be produced. In mining operations, there is usually but little variation in these con- ditions. For rock-drill work, the air pressure is generally from 60 to 80 lb. In using water-power, a compressor is driven most conveniently by a bucket impact wheel, such as the Pelton or Knight. The waterwheel is generally mounted directly on the crank-shaft, without the use of gearing. Since the power developed is uniform throughout the revolution of the wheel, the compressor should be of duplex form, in order to equalize the resistance so far as possible. The rim of the wheel is made extra heavy, to supply the place of a flywheel. When direct-connected, the wheel is of relatively large diameter, as its speed of rotation must of necessity be slow. With small high-speed wheels, the compressor cylinders may be operated through belting or gearing. In most cases, however, the waterwheel may be large enough to render gearing unnecessary. Impact wheels may be employed with quite small heads of water, by introducing multiple nozzles. To prevent the water from splashing over the compressor, the wheel is enclosed in a tight iron or wooden casing. The force of the water is regu- lated usually by an ordinary gate valve. If the head be great, it may be necessary to introduce means for deflecting the nozzle, so that, wnen the compressor is to be stopped suddenly, danger of rupturing the water main will be avoided. . _ Theory of Air Compression.— The useful effect or efficiency of a compressor is the ratio of the force stored in the compressed air to the work that has been expended in compressing it. This probably never reaches 80$, and often falls below 60$. # gee “Mines and Minerals," Vols. XIX and XX, for complete discussion of this subject by the same author. RATING OF COMPRESSORS. 195 Free air is air at ordinary atmospheric pressure as taken into the com- pressor cylinder. As commonly used, this means air at sea-level pressure (14.7 lb. per sq. in.) at 60° F. The absolute pressure of air is measured from zero, and is equal to the assumed atmospheric pressure plus gauge pressure. Air-compression calcu- lations depend on the two well-known laws: 1. Boyle's Law— The temperature being constant, the volume varies inversely as the pressure; or P V = P' V' — a constant; in which V equals volume of given weight of air at the freezing point, and the pressure P; V' equals the volume of the same weight of air at the same temperature and under the pressure P'. 2. Gay-Lussac's Law. —The volume of a gas under constant pressure, when heated, expands, for each degree of rise in temperature, by a constant pro- portional part of the volume that it occupied at the freezing point; or, V’ = V (1 + a £°), in which a equals for centigrade degrees, or 5 ^ T for Fahrenheit degrees. Theoretically, air may be compressed in two ways, as follows: 1. Isothermally , when the temperature is kept constant during compres- sion, and in this case, the formula P V = P r V' is true. 2. Adiabatically, when the temperature is allowed to rise withdut check during the compression. Since the pressure rises faster than the volume diminishes, the equation pr / y\n P V — P' V' no longer holds, and we have -p- = ( -yj ) > in which n equals 1.406. The specific heat of air at constant pressure is .2375, and at constant 2375 volume .1689, and n = = 1.406. In practice, compression is neither isothermal nor adiabatic, but inter- mediate between the two. The values of n for different conditions in practice are as follows, as determined from a 2,000-horsepower stage com- pressor at Q,uai de la Gare, Paris. For purely adiabatic compression, with no cooling arrangements, n = 1.406; in ordinary single-cylinder dry compressors, provided with a water-jacket, n is roughly 1.3; while in the best wet compressors (with spray injection), n becomes 1.2 to 1.25. In the poorest forms of compressor, the value n = 1.4 is closely approached. For large, well-designed compressors with compound air cylinders, the exponent n may be as small as 1.15. Rating of Compressors. — Compressors are rated as follows: (1) In terms of the horsenower developed by the steam end of the compressor, as shown bv indicator cards taken when running at full speed, and when the usual volume of air is being consumed. (2) Compressors for mines are often rated roughly as furnishing sufficient air to operate a certain number of rock drills; a 3" drill requires a volume of air at 60 lb. pressure, equal to 100 or 110 cu. ft. of free atmospheric air per minute. (3) In terms of cubic feet of free air compressed per minute to a given pressure. As the actual capacity of a compressor depends on the density of the intake air, it will obviously be reduced in working at an altitude above sea level, because of the diminished density of the atmosphere. The following table gives the percentages of output at different elevations: , Example.— Calculate the volume of air furnished by an 18" X 24" compressor work- ing at an elevation of 5,000 ft. above sea level, revolving 95 times per minute, and having a piston speed of 380 ft. per minute. 9 2 x 3.14 = 254.3 sq. in. = piston area. 254 3 -tttt X 380 = 668.8 cu. ft. = volume dis- 144 placed per minute by the piston; deducting 10$ for loss gives 602 cu. ft. At sea level at 15 80 lb. gauge pressure, this equals ^ ^ X 602 = 95 cu. ft. At an elevation of 5,000 ft., the output of a compressor would be 95 X 85$ — 80.7 cu. ft. per minute. Cooling.— Compressor cylinders may be cooled by either of the following methods: Altitude. Feet. Atmospheric Pressure. Pounds. Percentages of Output at Sea Level. 0 14.7 100.0 1,000 14.2 97.2 2,000 13.6 93.5 3,000 13.1 90.8 4,000 12.7 88.4 5,000 12.2 85.0 6,000 11.7 82.0 7,000 11.3 79.3 8,000 10.9 77.0 9,000 10.5 75.0 10,000 10.1 72.0 196 COMPRESSED AIR. (1) by injecting water into the cylinder, known as wet compressors; or (2) by jacketing the cylinder in water, known as dry compressors. Dry Versus Wet Compressors.— Up to about the year 1885 there seemed to be little doubt among mechanical engineers that wet compressors were, on the whole, superior to dry, because, by bringing the air into direct contact with water, the heat is most effectually absorbed. This view is correct, so far as heat loss alone is concerned, presided the water in the cylinder is properly applied. But the question of heat loss is not the only consideration. Low first cost and simplicity of construction are often more advantageous than a close approximation to isothermal compression. Latterly, the wet system has lost ground, owing to the fact that moisture is objectionable in the air, as it forms frost in the exhaust ports of the drills, and stops them up, and probably no wet compressors are now being built in the United States. In Europe, also, dry compressors have grown in favor, at least for mining plants and others of moderate size. c = TRANSMISSION OF AIR IN PIPES. The actual discharge capacity of piping is not proportional to the cross- sectional area alone, that is, to the square of the diameter. Although the periphery is directly proportional to the diameter, the interior surface resistance is much greater in a small pipe than in a large one, because, as the pipe becomes smaller, the ratio of perimeter to area increases. To pass a given volume of compressed air, a 1" pipe of given length re- quires over three times as much head as a 2" pipe of the same length. The character of the pipe, also, and the condition of its inner surface, have much to do with the friction developed by the flow of air. Besides imper- fections in the surface of the metal, the irregularities incident on coupling together the lengths of pipe must increase friction. There are so few relia- ble data that the influences by which the values of some of the factors may be modified are not fully understood; and, owing to these uncertain condi- tions the results obtained from formulas are only approximately correct. Among the formulas in common use, perhaps the most satisfactory is that of D’Arcy. As adopted for compress ed-air transm ission, it takes the form: j d 5 (pi — p 2 j D ” \ Wi l in which D = volume of compressed air in cubic feet per minute discharged at final pressure; „ . A . coefficient varying with diameter of pipe, as determined by d — dTameter^f pipe in inches (the actual diameters of If" and pipe are 1.38" and 1.61", respectively; the nomi- nal diameters of all other sizes may be taken for calcu- lations); l = length of pipe in feet; . pi = initial gauge pressure in pounds per square inch; p, = final gauge pressure in pounds per square inch; w[ = density of air, or its weight in pounds per cubic foot, at initiar pressure pi. . . , The values of the coefficients c for sizes of piping up to 12 are: 1" 4 45.3 5" 59.0 9" 2" 52.6 6" 59.8 10" 3"" 56.5 7" 60.3 11" 4 // 58.0 8" 60.7 12" v Some apparent discrepancies exist for sizes larger than 9", but they cause no very 'material differences in the results. . Another formula, published by Mr. Frank Richards, is as follows: H = V * L 10,000 IP a in which H = head or difference of pressure required to overcome friction and maintain the flow of air; y _ ydume of compressed air delivered in cubic feet per minute; L = length of pipe in feet; D = diameter of pipe in inches; . a = coefficient, depending on the size of pipe. .61.0 .61.2 .61.8 .62.0 TRANSMISSION OF AIR IN PIPES. 197 Values of a for nominal diameters of wrought-iron pipe: 1" .350 3" 730 8" 1.125 1±// 500 34 /' 787 10" 1.200 -1-4 H" 662 4" .840 12" 1.260 2" 565 5" .934 2£" 650 6" 1.000 The values of a fur l\" and 1\" pipe are not consistent with those for other sizes, for the reason stated above. In using this formula with its constants, the calculated losses of pressure are found to be smaller, and, conversely, the volumes of air discharged are larger, under the same condi- tions, than those obtained from D’Arcy’s formula. It must be remembered that, within certain limits, the loss of head or pressure increases with the square of the velocity. To obtain the best results, it is found in practice that the velocity of flow in the main air pipes should not exceed 20 or 25 ft. per second. When the initial velocity much exceeds 50 ft. per second, the percentage loss becomes very large; and, conversely, by using piping large enough to keep down the velocity, the friction loss may be almost eliminated. For example, at the Hoosac tunnel, in transmit- ting 875 cu. ft. of free air per minute, at an initial pressure of 60 lb., through an 8 " pipe, 7,150 ft. long, the average loss including leakage was only 2 lb. A volume of 500 cu. ft. of free air per minute, at 75 lb., can be transmitted through 1,000 ft. of 3" pipe with a loss of 4.1 lb., while if a 5" pipe were used the loss would be reduced to .24 lb. The velocity of flow in the latter case is only 10 ft. per second. In driving the Jeddo mining tunnel, at Ebervale, Pa., two 34 " drills were used in each heading, with a 6 " main, the maximum transmission distance being 10,800 ft. This pipe was so large in proportion to the volume of air required fur the drills (230 cu. ft. free air per minute) that the loss was reduced to an extremely small quantity. A calculation shows a loss of .002 lb., and the gauges at each end of the main were found to record practically the same pressure. A due regard for economy in installation, however, must limit the use ot very large piping, the cost of which should be considered in relation to the cost of air compression in any given case. Diameters of from 4 to 6 in. for the mains are large enough for any ordinary mining practice. Up to a length of 3,000 ft., a 4" pipe will carry, per minute, 480 cu. ft. of free air compressed to 82 lb., with a loss of 2 lb. pressure. This volume of air will run four 3" drills. Under the same conditions, a 6 " pipe, 5,000 ft. long, will carry 1,100 cu. ft. of free air per minute, or enough for 10 drills. A mistake is often made in putting in branch pipes of too small a diam- eter. For a distance of, say, 100 ft., a 1£" pipe is small enough for a single drill, though a 1" pipe is frequently used. While it is, of course, admissible to increase the velocity of flow in short branches considerably beyond 20 ft. per second, extremes should be avoided. To run a 3" drill from a 1" pipe 100 ft. long, would require a velocity of flow of about 55 ft. per second, causing a loss of 10 lb. pressure. . The piping for conveying compressed air may be of cast or wrought iron. If of wrought iron, as is customary, the lengths are connected either by sleeve couplings or by cast-iron flanges into which the ends of the pipe are screwed or expanded. Sleeve couplings are used for all except the large sizes. The smaller sizes, up to 1£ in., are butt-welded, while all from li in. up are lap-welded, to insure the necessary strength. Wrought-iron spiral-seam riveted or spiral-weld steel tubing is sometimes used. It is made in lengths of 20 ft., or less. For convenience of transport in remote regions, rolled sheets in short lengths may be had. They are punched around the edges, ready for riveting, and are packed closely — 4, 6 , or more sheets in a bundle. . . _ _ All joints in air mains and branches should be carefully made. Air leaks are more expensive than steam leaks because of the losses already suffered in compressing the air. The pipe may be tested from time to time by allow- ing the air at full pressure to remain in the pipe long enough to observe the gauge. In case a leak is indicated, it should be traced and stopped imme- diately. In putting together screw joints, care should be taken that none of the white lead or other cementing material is forced into the pipe. This would cause obstruction and increase the friction loss. Also, each length as put in place should be cleaned thoroughly of all foreign substances that may have lodged inside. To render the piping readily accessible for inspection 198 COMPRESSED AIR. and stoppage of leaks, it should, if buried, be carried in boxes sunk just below the surface of the ground; or, if underground, it should be supported upon brackets along the sides of the mine workings. Low points in pipe lines, which would form “pockets” for the accumulation of entrained water, should be avoided, as they obstruct the passage of the air. In long pipe lines, where a uniform grade is impracticable, provision may be made near the end for blowing out the water at intervals, when the air is to be used for pumps, hoists, or other stationary engines. For long lengths of piping, expansion joints are required, particularly when on the surface. They are not often necessary underground, as the temperature is usually nearly constant, except in shafts, or where there may be considerable variations of temperature between summer and winter. LOSSES IN THE TRANSMISSION OF COMPRESSED AIR. By E. Hill, Norwalk Iron Works Co. The increasing use that is being made of compressed-air engines for mine and underground work stimulates the inquiry regarding their efficiency. The situation is apparently very simple. An engine drives an air com- pressor, which forces air into a reservoir. The air under pressure is led through pipes to the air engine, and is there used after the manner of steam. The resulting power is frequently a small percentage of the power expended. In a large number of cases the losses are due to poor designing, and are not chargeable as faults of the system or even to poor workmanship. The losses are chargeable, first, to friction of the compressor. This will amount ordinarily to 15# or 20 #, and can be helped by good workmanship, but cannot probably be reduced below 10#. Second, we have the loss occasioned by pumping the air of the engine room, rather than air drawn from a cooler place. This loss varies with the season, and amounts to from 3# to 10#. This can all be saved. The third loss or series of losses arises in the compressing cylinder. Insufficient supply, difficult discharge, defective cooling arrangements, poor lubrication, and a host of other causes, perplex the designer and rob the owner of power. The fourth loss is found in the pipe. This has heretofore received by no means the consideration that the subject demands. The loss varies with every different situation, and is sub- ject to somewhat complex influences. The fifth loss is chargeable to fall of temperature in the cylinder of the air engine. Losses arising from leaks are often serious, but the remedy is too evident to require demonstration. No leak can be too small to require immediate attention. An attendant who is careless about packings and hose couplings will permit losses for which no amount of engineering skill can compensate. We can only realize 100# efficiency in the air engine, leaving friction out of our consideration, when the expansion of the air and the changes of its temperature in the expanding or air-engine cylinder are precisely the reverse of the changes that have taken place during the compression of the air in the compressing cylinder. But these conditions can never be realized. The air during compression becomes heated, and during expansion it becomes cold. If the air immediately after compression, before the loss of any heat, was used in an air engine and there perfectly expanded back to atmospheric pressure, it would, on being exhausted, have the same tem- perature it had before compression, and its efficiency would be 100#. But the loss of heat after compression and before use cannot be pre- vented, as the air is exposed to such very large radiating surfaces in the reservoir and pipes, on its passage to the air engine. The heat, which escapes in this way, did, while in the compressing cylinder, add much to the resistance of the air to compression, and since it is sure to escape, at some time, either in reservoir or pipes, it is evidently the best plan to remove it as fast as possible from the cylinder, and thus remove one element of resistance. Hence, we find compressors are almost universally provided with cooling attachments more or less perfect in their action, the aim being to secure isothermal compression, or compression having equal temperature throughout. Where the temperature rises, without check, during com- pression, the term adiabatic compression is employed. If air compressed isothermaliy is used with perfect expansion and the fall of temperature during expansion be prevented, then we will have 100# efficiency. But air will grow cold on being expanded in an engine, and hence we conclude that warming attachments have the same economic place on an air engine that cooling attachments have on an air compressor. In fact, we find attachments of this kind more particularly in large and TRANSMISSION OF COMPRESSED AIR. 199 permanently located engines, but, for practical reasons, their use on most of the engines for mine work is dispensed with, and the engines expand the air adiabaticallv, or without receiving heat. _ . ,, . The practical engineer, therefore, has. to deal with nearly isothermal compression, and nearly adiabatic expansion, and must also consider that thfair in reservoirs and pipes becomes of the same temperature as surround- ing objects. Consideration must also be had for the friction of the com- prlssor and the air engine. For the pressure of 60 lb., which is that most commonly used, the decrease in resistance to compression secured by the cooling attachments, is almost exactly equaled by the friction of the com- pressor. Hence it is safe, in calculating the efficiency of the air engine, to consider the compressor as being without cooling* attachments, and also as working without friction. The results of such calculations will be too high efficiencies for light pressures, which are little used; about correct for medium pressures, which ; are commonly employed; and too low for higher pressures and will thus have the advantage of not being overestimated. This result is occasioned by the fact that, owing to the slight heat m compressing low pressures of air, the saving of power by the cooling attachments is not equal to the friction of the machine, but at high pressures on account of the great heat, the cooling attachments are of great value and save very much more power than friction consumes. . , „ r QO In the expanding engines, the expansion never falls as low as the adiabatic law would indicate, owing to a number of reasons, but w e will consider the expansion as being adiabatic, as an error m calculations caused thereby will be on the “ safe side ’’ and the actual power will exceed the calculated power. We therefore consider the compressor and engine as following the adiabatic law of compression and expansion, and as working Wi wnh ttoview of the case, the efficiency of an air engine, working with perfect expansion, stated in percentages of the power required to operate the compressor, can be placed as below for the various pressures above the atmosphere. , < , ftn1 . Pressure above the atmosphere, 2.9 lb. Pressure above the atmosphere, 14.7 lb. Pressure above the atmosphere, 29.4 lb. Pressure above the atmosphere, 44.1 lb. Pressure above the atmosphere, 58.8 Pressure above the atmosphere, 73.5 lb. Pressure above the atmosphere, 88.2 lb. Wc observe that the efficiencies for the lower pressures are very much ..reYfer iffian for the high pressures, and the conclusion is almost irresistible fhsf to secure economical results we must design our air engines to run “St lhrht measures And, in fact, the consideration of tables similar to the above ? g heretXe published by writers on this subject, has led many en ^he e ffinehas?een entirely neglected. We notice that a pressure of 2.9 lb. • Sh i efficiency of 94.85$. It is clear that if the air were is credited with an length of the pipe and the velocity of flow conveyed through a P P , | . friction, then its efficiency, instead zero It is,’ therefore the power that leSttom the air, after it has passed the pipe and lost a part of its pressure* by friction, which we must consider when we state the efficiency of Ctor table of eSencies with a loss of 2,9 lb. in the pipe, now gives us dif- ferent values for the efficiencies at the various pressures. 94.85$ efficiency. 81.79$ efficiency. 72.72$ efficiency. 66.90 $ efficiency. 62.70$ efficiency. 59.48$ efficiency. 56.88$ efficiency. Pressure above the atmosphere, 2.9 lb. Pressure above the atmosphere, 14.7 lb. Pressure above the atmosphere, Pressure above the atmosphere, Pressure above the atmosphere, Pressure above the atmosphere, Pressure above the atmosphere, Tt will hP noticed that the light pressures have lost most by the pipe friction 2 9 lb having lost W: 14.7 lb. 11* and 88.2 lb. 9 nly a trifle over - of w We’ see that now 14.7 lb. is apparently the economical pressure to use Put a further careful analysis of the subject shows, that when the loss m the pi^e is 2.9 lb., then 20.5 lb. is the most economical pressure to use, and that 29.4 lb. 44.1 lb. 58.8 lb. 73.5 lb. 5.2 lb. 00.00$ efficiency. 70.44$ efficiency. 68.81$ efficiency. 64.87$ efficiency. 61.48$ efficiency. 58.62$ efficiency. 56.23$ efficiency. 200 COMPRESSED AIR. the efficiency is 71#. But 2.9 lb. is a very small loss between compressor and air engine, and cases are extremely exceptional where the friction of valves, pipes, elbows, ports, etc. does not far exceed this. Yet, with these con- ditions, which are very difficult to fill, we see that 20.5 lb. is the lightest pressure that should probably ever be used for conveying power, and that 71# is an efficiency scarcely to be obtained. . . Continuing our investigation and taking examples where the pipe friction amounts to 5.8 lb., we find the following efficiencies to correspond to the stated pressure: Pressure above the atmosphere, 14.7 lb. Pressure above the atmosphere, 29.4 lb. Pressure above the atmosphere, 44.1 lb. Pressure above the atmosphere, 58.8 lb. Pressure above the atmosphere, 73.5 lb. Pressure above the atmosphere, 88.2 lb. 57.14# efficiency. 64.49# efficiency. 62.71# efficiency. 60.12# efficiency. 57.73# efficiency. 55.59# efficiency. We again notice that as friction increases, or in other word s, when we beffin to use more air and make greater demands on the carrying capacity of the pipe, then we must increase pressure very considerably to attain the most economical results. If the demands are such as to increase the friction and loss in pipe to 14.7 lb., the air of 14.7 lb. pressure at the compressor is entirelv useless at the air engine. The* table will stand thus: Pressure above the atmosphere, 14.7 lb. 00.00^ efficiency. Pressure above the atmosphere, 29.4 lb. 48.53# efficiency. Pressure above the atmosphere, 44.11b. 55.13# efficiency. Pressure above the atmosphere, 58.8 lb. 55.64# efficiency. Pressure above the atmosphere, 73.5 lb. 54.74# efficiency. Pressure above the atmosphere, 88.2 lb. 53.44# efficiency. It is to be noticed that 88.2 lb. pressure has lost only about 3f# of its efficiency by reason of as high a friction as 14.7 lb., while the efficiency of the lower pressures has been greatly affected. As the friction increases we see that the most efficient, and, consequently , most economical, pressure increases. In fact, for any given friction in a pipe, the pressure at the compressor must not be carried below a certain limit. The following table gives the lowest pressures that should be used at the compressor, with varying amounts of friction in the pipe: 2.9 lb. friction. 20.5 lb. at compressor. 70.92# efficiency. 5.8 lb. friction. 29.4 lb. at compressor. 64.49# efficiency. 8.8 lb. friction. 38.2 lb. at compressor. 60.64# efficiency. 11.7 lb. friction. 47.0 lb. at compressor. 57.87# efficiency. 14.7 lb. friction. 52.8 lb. at compressor. 55.73# efficiency. 17.6 lb. friction. 61.7 lb. at compressor. 53.98# efficiency. 20.5 lb. friction. 70.5 lb. at compressor. 52.52# efficiency. 23.5 lb. friction. 76.4 lb. at compressor. 51.26# efficiency. 26.4 lb. friction. 82.3 lb. at compressor. 50.17# efficiency. 29.4 lb. friction. 88.2 lb. at compressor. 49.19# efficiency. So long as the friction of the pipe equals the amounts given above, an efficiency greater than the corresponding sums stated in the table cannot be expected. If we should have a case that corresponded to any of these cited in the table, we could only increase efficiency by reducing the friction. An increase in the size of pipe will reduce friction by reason of the lower velocity of flow required for the same amount of air. But many situations will not admit of large pipes being employed, owing to considerations of economy outside of the question of fuel or prime motor capacity. An increase of pressure will decrease the bulk of air passing the pipe, and in that proportion will decrease its velocity. This will decrease the loss by friction, and, as far as that goes, we have a gain. But we subject ourselves to a new loss, and that is the diminishing efficiencies of increasing pressures. Yet as each cubic foot of air is at a higher pressure, and. therefore, carries more power, we will not need as many cubic feet as before for the same work. It is obvious that with so many sources of gain or loss the question of selecting the proper pressure is not to be decided hastily . As an illustration of the combined effect of these different elements, we will suppose a very common case. Compressor 102 revolutions, pressure 52.8 lb., loss in pipe 14.7 lb., machine in mine running at 38.2 lb., efficiency 55.73#. FRICTION OF AIR IN PIPES, 201 So Ions 1 as the friction of the pipe amounts to 14.7 lb., we have seen that 52 8 lb. is the best pressure and 55.73$ the greatest efficiency. We will reduce the friction by reducing the bulk of air passing through the pipe. We reduce the cylinder of the air engine so that it requires 47 lb. pressure to do the same work as before. We find now that the inction of pipe drops to 11 7 lb. The pressure on the compressor rises to 58.8 lb., its number of revolu- tions falls to 100, and the resulting efficiency is 57.22$. Another change of pressure on compresscir to 64.7 lb. would decrease its revolutions to 93, friction to 8.8 lb., and efficiency would rise to 57.94$. Still again increasing the pressure to 73.5 lb., we have only 84 revolutions of com- pressor, 5.8 lb. loss in pipe, and efficiency of 57./ 3$. In this last case the efficiency begins to fall off a little, and higher pressures would now show less efficiency; but, in comparison with the first example, we find we are doing the same work in the mine with a trifle less power and with a decrease of nearly 20$ in the speed oi the compressor. Other common examples can be shown where an increase of pressure would result in wonderful increase in efficiency and economy. There are many cases where light pressures and high velocity in the pipe will convey a given power with greater economy than higher air pressures and lower speed of flow through the pipe. But these cases arise mostly when the higher air pressures become very much greater than are at present m com- m °Therefore, in estimating the efficiency of the complete outfit, we find that the pipe and the pressure are very important elements, and must be deter- mined with care and skill to secure the most satisfactwy results. As the volume and power of air vary with its pressure, the size and consequent cost of compressor for a certain work would also be affected by the pressure. To plan an outfit for a mine, due regard must be had to cost of fuel or prime motor power, and also to cost of compressor, pipes, and machinery, as the saving in one is often secured by a sacrifice in the other. . Next to determining the size of pipe, the skilful engineer has need of further care in the proper position of reservoirs, branches, drains, and other attachments, as only by the exercise of good judgment m this can satis- factory working be secured. • The fact that, on account of the diminished density of the atmosphere at high altitudes, air compressors do not give the same results as at sea level, should also be taken into consideration when a compressor is to be installed in a mountainous region. . . . . Friction of Air in Pipes.— Air in its passage through pipes is subject to friction in the same manner as water or any other fluid. Tim pressure at the compressor must be greater than at the point of consumption m order to overcome this resistance. The power that is needed to produce the extra pressure representing the friction of the pipe is lost, as there can be no use- ful return for it. The friction is affected by very many circumstances, but chiefly to be noted is the fact that it increases in direct proportion to the length of the pipe and also as the square of the velocity of the flow of air. The pressure of the air does not affect it. . The losses bv friction may be quite serious if the piping system -is poorly designed, and, on the other hand, extravagant expenditure in pipe may result from a timid overrating of the evils of friction. A thorough knowl- edge of the laws governing the whole matter, as well as a ripe experience, is necessary to secure true economy and mechanical success. The loss of power in pipe friction is not always the most serious result. When a number of machines are in use in a mine, and the pipes are so small as to cause a considerable loss of pressure by friction, then there will be sudden and violent fluctuations in pressure whenever a machine is started or stopped. Breakages will be of common occurrence, as the changes are too quick to be entirely guarded against by the attendant. Perfectly even pres- sure at the compressor is no safeguard against this class of accidents. The trouble arises in the pipe, and the remedy must be applied there. A system of reservoirs and governing valves will regulate these matters and allow successful work to be done with pipes, which would otherwise be entirely i n a Th e S ordin ary formulas for calculating the volume of air transmitted through a pipe do not take into account the increase of volume due to reduction of pressure, i. e., loss of head. To transmit a given volume of air at a uniform velocity and loss of pressure, it would be necessary to construct the pipe with a gradually increasing area. This, of course, is impracticable, 202 COMPRESSED AIR. and in pipe of uniform section both volume and velocity must increase as the pressure is reduced by friction. The loss of head in properly propor- tioned pipes is so small, however, that in practice the increase in volume is usually neglected. Loss of Pressure in Pounds per Square Inch, by Flow of Air in Pipes. Calculated for pipes 1,000 ft. long; for other lengths, the loss varies directly as the length. Velocity of Air at Entrance to Pipe. 1" Pipe. 2" ' Pipe. 2h" Pipe L Meters per Second. Feet per Second. Loss of Pressure. Pounds. Cubic Feet of Free Air Passed per Minute When Compressed to 60 Lb. Above the Atmosphere. Cubic Feet of Free Air Passed per Minute When Compressed to 80 Lb. Above the Atmosphere. Loss of Pressure. Pounds. Cubic Feet of Free Air Compressed to 60 Lb. Cubic Feet of Free Air Compressed to 80 Lb. Loss of Pressure. Pounds. Cubic Feet of Free Air Compressed to 60 Lb. Cubic Feet of Free Air Compressed to 80 Lb. 1 3.28 .1435 6 7 .0794 23 29 .0574 32 41 2 6.56 .6405 12 15 .3050 46 59 .2562 65 82. 3 9.84 1.4545 18 22 .7216 69 88 .5818 97 124 4 13.12 2.5620 24 29 1.2566 93 117 1.0248 130 165 5 16.40 3.9345 29 37 1.9642 116- 146 1.5738 163 207 6 19.68 5.4225 35 44 2.7120 139 175 2.1690 195 247 8 26.24 10.2480 47 59 5.0264 185 234 4.0992 260 330 10 32.80 15.7380 59 74 7.8568 232 294 6.2952 326 413 3" Pipe. 4" Pipe. 5" Pipe. 1 3.28 .0463 48 60 .0347 86 109 .0287 134 169 2 6.56 .2092 96 121 .1525 172 217 .1281 268 239 3 9.84 .4880 144 182 .3608 258 326 .2909 402 509 4 13.12 .8381 193 243 .6283 343 436 .5124 537 678 5 16.40 1.3176 241 304 .9821 429 544 .7869 671 844 6 19.68 1.8080 289 364 1.3560 515 653 1.0845 805 1,017 8 26.24 3.3525 386 486 2.5132 687 871 2.0496 1,073 1,357 10 32.80 5.2704 480 607 3.9284 859 1,088 3.1476 1,342 1,696 6" Pipe. 8" Pipe. 10" Pipe. 3.28 .0232 193 244 .0173 343 434 .0143 537 680 2 6^56 .1046 386 488 .0762 687 864 .0640 1,073 1,359 3 9.84 .2440 579 633 .1805 1,030 1,303 .1455 1,610 2,039 4 13.12 .4190 772 977 .3141 1,373 1,736 .2562 2,146 2,719 5 16.40 .6588 965 1,221 .4910 1,717 2,171 .3934 2,683 3,399 5 19.68 .9040 1,158 1,466 .6780 2,060 2,605 .5423 3,220 4,079 8 26.24 1.6762 1,544 1,954 1.2556 2,747 3,473 1.0248 4,293 5,438 10 32.80 .2.6352 1,931 2,443 1.9642 3,434 4,342 1.5738 5,367 6,798 The resistance is not varied by the pressure, only so fer as changes in pressure vary the velocity. It increases about as the square of the velocity , an E^ows^ho^ leaks in pipes all tend to reduce the pressure in addition to the losses given in the table. ELECTRICITY. 203 Table of Loss by Friction in Elbows. An elbow with a radius as can be made. Radius of elbow, 5 diams. Radius of elbow, 3 diams. Radius of elbow, 2 diams. Radius of elbow, H diams. Radius of elbow, H diams. Radius of elbow, 1 diam. Radius of elbow, f diam. Radius of elbow, £ diam. of one-half the diameter of the pipe is as short Equivalent length of straight pipe, 7.85 diams. Equivalent length of straight pipe, 8.24 diams. Equivalent length of straight pipe, 9.03 diams. Equivalent length of straight pipe, 10.36 diams. Equivalent length of straight pipe, 12.72 diams. Equivalent length of straight pipe, 17.51 diams. Equivalent length of straight pipe, 35.09 diams. Equivalent length of straight pipe, 121.20 diams. ELECTRICITY. . PRACTICAL UNITS. In electrical work it is necessary to have units in terms of which to express the different quantities entering into calculations. The four most important of these are used to express strength of current; electrical pressure , or electromotive force; resistance; power. . The strength of current bowing in a wire may be measured in several wavs. If a compass needle be held under or over a wire, it will be deflected and will tend to stand at right angles to the wire. The stronger the current, the greater the deflection of the needle. If the wire carrying the current be cut and the ends dipped into a solution of silver nitrate, silver will be deposited on the end of the wire toward which the current is flowing, and the amount of silver deposited in a given time will be directly proportional to the average strength of current flowing during that time. When the current flowing in a wire is spoken of, the strength of the current is meant. Unit Strength of Current.— The unit used to express the strength of a cur- rent is called the ampere. If a current of 1 ampere be sent through a bath of silver nitrate, .001118 gram of silver will be deposited per second. The expression of the flow of current through a wire as so many amperes is analogous to the expression of the flow of water through a pipe as so many gallons per second. Electromotive Force.— In order that a current may flow through a wire, there must be an electrical pressure of some kind to cause the flow. In hydraulics, there must always be a head or pressure before water can be made to flow through a pipe. It is also evident that there may be a pressure or head without there being any flow of water, because the opening in the pipe might be closed; the pressure would, however, exist, and, as soon as the valve closing the pipe was opened, the current would flow. In the same way, an electrical pressure or electromotive force (usually written E. M. F.) may exist in a circuit, but no current can flow until the circuit is closed or until the wire is connected so that there will be a path for the current. Unit Electromotive Force (E. M. F.).— The practical unit of electromotive force is the volt. It is the unit of electrical pressure, and fulfils somewhat the same purpose as “pounds per square inch” in hydraulic and steam engineering. The E. M. F. furnished by an ordinary cell of a battery usually varies from .7 to 2 volts. A Daniell cell gives an E. M. F. of 1.072 volts. A pressure of 500 volts is generally used for street-railway work, and, for incan- descent lighting, 1 10 volts is common. Resistance.— All conductors offer more or less resistance to the flow of a current of electricity, just as water encounters friction in passing through a pipe. The amount of this resistance depends on the length of the wire, the diameter of the wire, and the material of which the wire is composed. The resistance Of all metals also increases with the temperature. Unit of Resistance — The practical unit of resistance is the ohm. A con- ductor has a resistance of 1 ohm when the pressure required to set up 1 ampere through it is 1 volt. In other words, the drop , or fall, in pressure through a resistance of 1 ohm, when a current of 1 ampere is flowing, is 1 volt. 1,000 ft. of copper wire .1 in. in diameter has a resistance ot nearly 1 ohm at ordinary temperatures- 204 ELECTRICITY. Ohm’s Law.— The law governing the flow of current in an electric circuit was first stated by Dr. G. S. Ohm, and is known as Ohm's law. This law has since stood the test of exhaustive experiment, and has been found correct. Ohm’s law may be briefly stated as follows: The strength of the current in any circuit is directly proportional to the electromotive force in the circuit , and inversely proportional to the resistance of the circuit. This means that if the resistance of a circuit were fixed, and the E. M. F, varied, the current would be doubled if the E. M.F. were doubled. Also, if the E. M. F. were fixed, and the resistance doubled, the current would be halved. Let E = electromotive force in volts; R = resistance in ohms; C = current in amperes. Then, C = -=, or R = — , or E = C R. R C The last two forms are useful in many cases where the usual form E C — -== is not directly applicable. R Example. — A dynamo D which generates 110 volts, is connected to a coil of wire C, Fig. 1, which has a resistance of 20 ohms; what current will flow, supposing the resistance of the rest of the circuit to be negligible ? We have E = 110 volts; R — 20 ohms; hence, C = ^ = 5.5 amperes. were 8 amperes and the E. M. F. of the dynamo 110 volts, the resistance of the circuit must be Tf lift R = ^; R = ~ = 13.75 ohms. C o Electrical Power.— The electrical power expended in any circuit is found by multiplying the current flowing in the circuit by the pressure required to force the current through the circuit. In other words, W = E C; where W is the power expended, E is the E. M. F., and C is the current. When E is expressed in volts and C in amperes, then W is expressed in watts. The watt is the unit of electrical power, and is equal to the power developed w T hen 1 ampere flows under a pressure of 1 volt. The watt is equal to horsepower. We have, then, the following general relations: Let E = electromotive force in volts; C = current in amperes; R = resistance in ohms; W — power in watts; H. P. = horsepower. Then, W = E C, but E = C R; hence, W = C 2 R. That is, the power in watts expended in any conductor of which the resistance is R, and through which a current C is flowing, is equal to the product of the squares of the current and the resistance. The energy used in forcing a current through the wire reappears in the form of heat; hence, we may say that the heating effect of a current flowing in a conductor is proportional to the square of the current. From the preceding, we also have np_!i = I I 746 746' This relation is very useful for calculating power in terms of electrical units The watt is too small a unit for convenient use in many cases, so that the kilowatt, or 1,000 watts, is frequently used. This is sometimes abbreviated to K.W, CIRCUlfS. 205 The Unit of Work Is the Watt-Hour.— This is the total work done when 1 watt is expended for 1 hour. For example, if a current of 1 ampere were made flow for 1 hour through a resistance of 1 ohm, the total amount of work done would be 1 watt-hour. A kilowatt-hour is the total work done when 1 kilowatt is expended for 1 hour. It is about equivalent to 1} horsepower for 1 hour. ELECTRICAL EXPRESSIONS AND THEIR EQUIVALENTS. {Arranged for Convenient Reference by C. W. Hunt.) One Watt f A rate of doing work. 1. ampere per sec. at one volt. .7373 foot-pound per second. 44.238 foot-pounds per minute. ^ 2,654.28 foot-pounds per hour. .5027 mile-pound per hour. .00134 horsepower. 755 horsepower. One Kilowatt A rate of doing work. 737.3 foot-pounds per second. 44,238. foot-pounds per minute. 502.7 mile-pounds per hour. 1.34 horsepower. One Horse- power r A rate of doing work. I 550. foot-pounds per second. ! 33,000. foot-pounds per minute. \ 375. mile-pounds per hour, i 746. watts. L .746 kilowatt. One Watt- Hour One Horse- POWKR- Hour 1 A quantity of work. 2,654.28 foot-pounds. 503 mile-pound. 1. ampere hour X one volt. .00134 horsepower-hour, horsepower-hour. r A quantity of work. I 1,980,000. foot-pounds. 375. mile-pounds. ! 746. watt-hour. I .746 kilowatt-hour. One Ampere- Hour A quantity of current. One ampere flowing for one hour, irrespective of the voltage. Watt-hour -5- volts. r Force moving in a circle. Torque ^ A force of one pound at a radius of t one foot. CIRCUITS. The path through which a current flows is generally spoken of as an electric circuit. This path may be made up of a number of different parts. For example, the line wires may constitute part of the circuit, and the remainder may be composed of lamps, motors, resistances, etc. In practice, the two kinds of circuits most commonly met with are (1) those in which the different parts of the circuit are connected in series; (2) those in which the different parts of the circuit are connected in multiple or parallel. 1. Series Circuits.— In this kind of circuit, all the component parts are con- nected in tandem, so that the current flowing through one part also flows 206 ELECTRICITY. through the other parts. Fig. 2(a) represents such a circuit made up of a different number of parts. The current leaves the dynamo D at the + side and flows through the arc lamps aaaa , thence through the incandescent lamps 1 1 1, thence through the motor m and resistance r, back to the dynamo, thus making a complete circuit. All these different parts are here connected in series, so that the current flowing through each of the parts #nust be the same unless leakage takes place across from one side of the circuit to the other, and this would be impossible if the lines were properly insulated. The pressure furnished by the dynamo must evidently be the sum of the pressures required to force the current through the different parts, /the most common use of this system is in connection with arc lamps. These lamps are usually connected in series, as shown in Fig. 2 (&). The objections to this system of distribution for general work are that the breaking of the circuit at any point cuts off the current from all parts of the circuit; also the pressure generated by the dynamo has to be very high if many pieces of apparatus are connected in series. In such a system, the dynamo is pro- vided with an automatic regulator that increases or decreases the voltage : of the machine, so that the current in the circuit is kept constant, no matter how many lamps or other devices are in operation. For this reason, such circuits are often spoken of as constant-current circuits. . 2 Parallel Circuits.— In this type of circuit, the different pieces of appa- ratus are connected side by side, or in parallel, across the mam wires from the dynamo, as shown in Fig. 2 (c). In this case, the dynamo D supplies current through the mains to the arc lamps a, incandescent lamps J and motor m. This system is more widely used, and it will be seen at once from the figure that the breaking of the circuit through any one piece of apparatus will not prevent the current from flowing through the other parts. Incan- descent lamps are connected in this way almost exclusively. The lamps are connected directly across the mains, as shown in Fig. 2 (d). Street cars and mining locomotives are operated in the same way, the trolley wire consti- tuting one main and the track the other, as shown in Fig. 2(e). By adopting this system, any car can move independently of the others, and the current mav be turned off and on at will. In all these systems of parallel distribu- tion the pressure generated by the dynamo is maintained constant, no matter what current the dynamo may be delivering. For example, m the lamp svstem Fig- 2 (d). the dynamo would maintain a constant E. M. J?. ot 110 volts. ’Each lamp has a fixed resistance, and will take a certain current amperes^ when connected across the mains. As the lamps are turned on the current delivered by the dynamo increases, the pressure remaining constant. In street-railway work, the pressure between trolley and track is kept in the neighborhood of 500 volts, the current varying with the number of cars in operation. In mine-haulage plants, the pressure is usually 250 or 500 volts, the former being generally preferred as being less dangerous. Lamps may also be connected in series multiple, as shown in Fig 2 (c). Here the two 125-volt lamps 1 1 are connected m series across the 250-volt circuit. Such an arrangement is frequently used in mines when lamps are circuits 1 a s those just described are called constant-potential or con- stant-pressure circuits, to distinguish them from the constant-current circuit mentioned previously. RESISTANCES IN SERIES AND MULTIPLE. Resistances in Lines.— If two or more resistances are connected in series, Fiff 2 ( f ) their total combined resistance is equal to the sum of their sepa- rate resistances. If R equal total combined resistance, and R U R>, R s are the separate resistances connected in series, then, R = -Ri + ^ . nhTT1 Example.— I f the separate resistances were Ri = 10 ohms, i? 2 — 1 ohm, and = 30 ohms, then these three combined would be equivalent to a ^"Rlthtancerin “pVralleK-lf a = numbeTof resistances are . connected in parallel the reciprocal of their total combined resistance is equal to the sum of the reciprocals of the separate resistances. In Fig. 2 (g), three resist- ances are shown connected in parallel. It is evident that the total resistance of such a Combination must be lower than that of the lowest resistance entering into the combination. If the resistances m this case were all equal, ELECTRIC WIRING. 207 the resistance of the three combined would be one-third the resistance of one of them, because a current passing through the three combined could split up between three equal paths, instead of having only one path to pass through. If R represents the combined resistance, and R u R 2 , and R 3 the separate resistances, the following relation is true: + -L + JL R Ri R 2 R& from which R = R\ Ro R$ R 2 Rz + Lti R,i + Ri R-z 13 R If the three resistances were all equal, we would have or R = Example.— Three resistances of 3, 10, and 5 ohms are connected in par- allel. What is their combined resistance? We have l = i+s + i- orie = 150 50 + 15 + 30 150 95 1.58 ohms. Shunt.— When one circuit B, Fig. 2(h), is connected across another A, so as to form, as it were, a by-pass, or side track, for the current, such a circuit is called a shunt, or it is said to be in shunt with the other circuit. ELECTRIC WIRING (CONDUCTORS). Materials.— Practically all conductors used in electric lighting or power work are of copper, this metal being used on account of its low resistance. Iron wire is used to some extent for conductors in telegraph lines, and steel is largely used as the return conductor in electric-railway or haulage plants wherti the current is led back to the power station through the rails. The resistance of iron or steel varies from six to seven times that of copper, depending on the quality of the metal. Aluminum is coming into use as a material for conductors, and in future may play an important part in electric transmission. It is so much lighter than copper that it is able to compete with it as a conductor, even though its cost per pound is higher and its conductivity only about 6(K that of copper. Forms of Conductors.— Most of the conductors used are m the form of copper wire of circular cross-section. Conductors of large cross-section are made up of a number of strands of smaller wire twisted together. For electrolytic plants, copper-refining plants, etc., copper bars of rectangular cross-section are frequently used. . A . . , . Wire Gauge.— The gauge most generally used in America to designate the different sizes of copper wire is the American, or Brown & Sharpe (B & S.). The sizes as given by this gauge range from No. 0000, the largest 460 in. diameter, to No. 40, the finest, .003 in. diameter. Wire drawn ’to the sizes given by this gauge is always more readily obtained than sizes according to other gauges; hence, in selecting line wire for anv purpose it is always desirable, if possible, to give the size required as a wire of the B. & S. gauge. A wire can usually be selected from this gauge, which will be verv nearly that required for any specified case. . Estimation of Cross-Section of Wires.— The diameter of round wires is usually given in the tables in decimals of an inch, and the area of cross- section is given in terms of a unit called a circular mil. This is done simply for convenience in calculation, as it makes calculations of the cross-section much simpler than if the square inch were used as the unit area. A mil is i of an inch, or .001 in. A circular mil is the area (in decimals of a square inch) of a circle, the diameter of which is in., or 1 mil. The circular mil is therefore equal to (.001) 2 = .0000007854 sq. in. If the diameter of the conductor were 1 in., its area would be .7854 sq. in.,. and the number of circular mils in its area would -be 0000007 ^54 = 1,000,000; but 1 in. = 1,000 mils, and (1,000) 2 = 1,000,000; hence the following is true: CM — d-\ or the area of cross-section of a wire in circular mils is equal to the square of its diameter expressed in mils. . . Example.— A wire has a diameter of .101 in. What is its area in circular ^llOlin. = 101 mils. Hence, CM = (101) 2 = 10,201. vide imbt >lum R0P1 cj be u 3 The amount of current that a given wire can carry without overheating depends very largely on the location of the wire. For example, a wire strung in the open air will carry a greater current, with a given temperature rise, than the same wire would if boxed up in a molding or conduit. The 212 ELECTRICITY. table on page 209 giyes the approximate sate carrying capacity of wires when strung in the air. , , In order to keep down the size of wire required to transmit a given amount of power over a given distance, with a certain allowable loss, the current must be kept as small as possible. Now, for a given amount of power the current can only be made small by increasing the pressure, because the number of watts, or power delivered, is equal to the product of the current and the pressure. As a matter of fact, if the pressure m any given case be doubled, the amount of copper required will be only one- fourth as great; in other words, for a given amount of power transmitted, the weight of copper required decreases as the square of the voltage. It is at once seen then, that if anv considerable amount of power is to be trans- mitted over long distances, a high line pressure must be used or else the cost of copper becomes prohibitory: The use of high pressures m power trans- mission will be taken up in connection with alternating currents. Insulated Wires.— For most overhead line work using modern voltages, weather-proof insulated wire is used. This wire is covered with two or three braids of cotton, and treated with insulating compound. For inside work and in places where a better quality of insulation is required, rubber-covered wires are used. The following table gives the approximate weight of weather-proof line wire. The cost of the wire per pound vanes considerably owing to the variations in the price of copper; about 18 cents per pound may be taken as an approximate figure in making calculations. Weather-Proof Line Wire (Roebling’s). Number. B.&S. Gauge. Double Braid. Triple Braid. Outside Diameter. 32ds Inch. Weight. Pounds. Outside ; Diameter. 32ds Inch. Weight. Pounds. Per 1,000 Ft. ; Per Mile. Per i 1.000 Ft. Per Mile. 0000 20 716 3,781 24 775 4,092 000 18 575 3,036 22 630 3,326 00 17 465 2,455 18 490 2.58/ 0 16 375 1.9S0 17 400 2,112 1 15 285 1,505 16 306 1,616 2 14 245 1.294 15 268 1,415 3 13 190 1.003 14 210 1,109 4 11 152 803 12 164 866 5 10 120 634 11 145 766 6 9 98 518 10 112 591 g 8 66 349 9 78 412 10 7 45 238 8 55 290 12 6 30 158 7 35 1 185 14 5 20 106 6 26 137 16 4 14 74 5 20 106 18 3 10 53 4 16 85 For high-tension lines, it is customary to use bare wires ana msuiaie them thoroughlv on special porcelain insulators. The ordinary weather- proof wire insulation is of little or no use as a protection when these high pressures are used, and it only makes the line more dangerous because of the appearance of false security that it gives. In many cases, ^ is also better to use bare feeders for mine-haulage plants, because the ordinary insulation soon becomes defective in a mine, and a wire in thisconditionis really more dangerous than a bare wire, because the latter is known to be dangerous and will be left alone. CURRENT ESTIMATES. Before calculating the size of wire required for any given case, it is necessary to know the current, and the method of getting at this will depend on what the current is to be used for. INCANDESCENT LAMPS. 213 Incandescent Lamps.— These are usually operated ou 110-volt circuits, Fig. A, or on the three-wire system, as shown in Fig. 5. In the three- Wire system, two 110-volt dynamos are connected in series so that the voltage across the outside wires is 220. The neutral wire a a connects to the point b where the machines are connected together. The wire a a merely serves to carry the difference in the currents on the two sides of the system, in case more lamps should he burning on one side than on the other. The outside wires for such a system are calcu- lated as if the lights were operated . . .. . ,. . two in series across 220 volts. The middle wire is usually made equal m size to the outer wires. An ordinary 16 c. p. incandescent lamp requires about 55 watts for its operation; a 32 c. p. lamp requires about 110 watts. Hence, in the case of ordinary parallel dis- tribution, as shown in Fig. 4, the dy- namo will deliver about i ampere for each 16 c. p. lamp operated, and 1 am- pere for each 32 c. p. lamp. In the case of the three-wire sys- tem, each pair of 16 c. p. lamps will take \ ampere, and the total number of amperes in the outside wires will be one-fourth the num- ber of lamps operated. . , ... . , „ _ Example.— A certain part of a mine is to be illuminated by fifty 16 c. p. lamps and ten 32 c. p. lamps. This portion of the mine is 1,000 ft. from the dynamo room, and the allowable drop in pressure is 5 °J. The lamps are to be run on a 110-volt system. Find the size of wire required. Fifty 16 c. p. lamps require - 25 amperes Ten 32 c. p. lamps require 10 amperes Total current 35 amperes We have, then, circular mils = 10 ' 8X * 35 * — = 137 - 454 circular mils ’ or about a No. 00 B. & S. wire. , . , , ., Example. — Take the same case as in the last example, but suppose the lights to be operated on the three-wire system. There will then be twenty - five 16 c. p. lamps and five 32 c. p. lamps on each side of the circuit, and the total current in the outside wires will be 17.5 amperes. The voltage between the outside wires will be 220, and we will have 10.8 X 1,0 00 X 2 X 17.5 X 100 _ 34 353 circular mils, 220 X 5 or about a No. 5 B. & S. wire. If We make the central wire also of this size, it is seen that this system would require three-eighths the amount of copper called for by the Pl al d 110-volt system. There is the disadvantage that two dynamos are needed. Note.— The length to be used in the wiring formula is the average dis- tance traversed by the current in the conductor. For example, it, a $ in Fig. 6 (a), the lamps were all grouped or bunched at the end of the line, tne length used in the formula would be twice that from G to A, because the whole current has to flow out to A through one main and back through the other. In other words, the whole current here passes through the whole length of the line. In case the load is uniformly distributed all along the line, as shown in Fig. 6 (5), it is evident that the current decreases step 'by step from the dynamo to the end. In such a case, the length or distance to be used in the formula is one-half that used in the former case, or simply the distance from the dynamo to the end, instead of twice this distance. circular mils 214 ELECTRICITY. Arc LamDS — Arc lamps are frequently run on constant-potential circuits, and usually consume from 400 to 500 watts. There are so many types of these lamps that it is difficult to give any current estimates that will be gen- erally applicable. Enclosed arc lamps usually take from 3 to 5 amperes when run on 110-volt circuits. Mot ors —Practically all the motors used in mining work are run on the constant-potential system, either at 250 or 500 volts. The efficiency of ordi- narv motors will vary from 70 $ to 9 096 or higher, depending on the size. The efficiency is greater with the larger machines, and, for the ordinary run o( motors, it will probably lie between 1 80$ and 90/,. By efficiency is here meant the ratio of the useful output at the pulley or pinion of the motor to the total input. The accompanying table gives the efficiency of motors of oidinary size. approximate Motor Efficiency. f to 11 H. P., inclusive = 75 $ efficiency 3 to 5 H. P., inclusive = 80$ efficiency 71 to 10 H. P., inclusive = 85$ efficiency 15 H. P. and upwards = 90$ efficiency If the required output in horsepower is known, the input will be w _ H. P. X 746 efficiency W and the current required at full load will be C = where E is the voltage between the mains at the motor. Conductors for Electric-Haulage Plants.-In electric-haulage plants the rails take the place of one of the conductors, so that, m calculating the * size of feeders required, only the overhead conductors are taken into account. It is a difficult matter to assign any definite value to the resisto circuit, as it depends very largely on the quality of the rail bonding at the ioints. If this bonding is well done, the resistance of the return circuit should be very low, because the cross-section of the rails is comparatively large. For calculating the supply feeders, we may use the approximate fOTmUla ’ • . . .. 14XXXCX100 circular mils = £x ^ drop • In this case, L is the average length of feeder over which the power is to be transmitted. It will be noticed that the constant 10.8 appearing m the previous formulas has here been increased to 14. This has been done to allow, approximately, for the track resistance, but this cons tant might vary con- siderablv, depending on the quality of the rail bonding. If 1 ; ^^ad is ali bunched at the end of the feeder, X is the actual length of the feeder in fee If the load is uniformly distributed all along the line, as it would be it a number of locomotives were continually moving along the line, the dis- tance L in the above formula would be taken as one-half that used in l the case where the load was bunched at the end. In other words the whole current C would only flow through an average of one-half the length of tne line. DYNAMOS AND MOTORS. 215 Example.- In Fig. 7, a b represents a section of track 4 ,°° 0 ft. long. thp dvnamo c to the beginning of the section, the distance is 1,200 ft. The Jmllev wheis No 00 B & S., and is fed from the feeder at regular mterva Is. Two mining locomotives are operated, each of which takes an average cur W 75 ZZr The total allowable drop to the end of the line is to be xrf 0 f +^0 terminal voltage, which is 500 volts. Calculate the size of feeder required, assuming that the constant 14, in the formula, takes account of the reS Since the locomotives^are moving from place to place ’iJ ie 4 c ™ te f j 0f tribution for the load may be taken at tne center of the 4,000 ft. 1 e distance L will then be 1,200 + 2,000 = 3,200 ft 150 amperes; hence, we have ^ ^ x 150 x 100 circular mils The total current will be = 268,800. 500X5 . This would require either a stranded cable or the use of two No. 00 wires in uarahSfrom^to o From a to b we have the No .00 trolley wire m narallel with the 'feeder; hence, the section of feeder a b may be a J^g e No 00 wire In many cases, the drop is allowed to run as high 10/n, because the loads are usually heavier, and the distances longer, than m the example given above. . DYNAMOS AND MOTORS. A dynamo is a machine for converting mechanical energy into electrical energv bv moving conductors relatively to a magnetic field. riT . rr . r An y electric motor is a machine for converting electrical energy into mechanical energy by the relative motion between conductors carrying a current and a ma^netic^eld. b of conductors are made to move across a magnetic held by means of a steam engine or other prime mover, and the result is that an E. M. F. is set up in the conductors, and this E. M. I . will set up a current if the circuit is closed. • A , ,, , In the case of a motor, a number of conductors are arranged so that they are free to move across a magnetic field, and a current is sent through these “nd"s from some source of electric current The current flowing through these conductors reacts on the magnetic field and causes tne conductors to move, thus converting the electrical energy delivered to the m °As r fa^as^e^^ica^coni^uction goes, dynamos and motors are almost identical, and the operation of the motor is exactly the reverse to that of the dy DvSamos and motors may be divided into two general classes: mos and motors for direct current ; (5) dynamos and motors for alternating current. . DIRECT-CURRENT DYNAMOS. Prinrinle of Action. -Direct-current dynamos are those that furnish a current that always flows in the same direction. This kind of dynamo is largely used for incandescent lighting, and also for the operation of street raU A dynamo generates an E. M. F. by the motion of conductors across a magnetic field; hence, at the outset, it is seen that there must be at least two essential parts to a dynamo; namely, a magnet of some kind to set up a magnetic field, and a ‘series of conductors arranged so that they may be moved or revolved in the magnetic field. The first part is known as the 216 DYNAMOS AND MOTORS. field magnet, or very often, simply as the field. The second part is known as the armature. The field is supplied by means of a powerful electromagnet which is magnetized by the current in the field coils. Fig. 8 shows a typical six-pole magnet of this kind; B , B are the magnetizing coils, which, when a current is sent through them, form powerful magnetic poles at N, S. The framework A of such a field magnet is usually made of cast iron or cast steel. These field magnets may have any number of poles, but machines of ordinary size are usually provided with from two to eight poles. The armature usually con- sists of a number of turns of insulated copper wire, arranged around the periph- ery of a ring or drum built up of soft iron sheets. Fig. 9 shows the construction of a typical armature of the ring type. The winding is divided into a number of sections, and the terminals connected to the commutator. This commutator consists of a number of copper bars, insulated from each other by means of mica, the bundle of bars being clamped firmly into place and turned up to form a true cylindrical sur- face. The sections in the commutator correspond with those in the armature, and the use and operation of the commutator will be described later. The winding on the ring is endless, i. e., it consists of a number of coils or sections c, the end of one section Fig. 8. COMPLETE ARMATURE. conductor Fig. 9. being joined to the beginning of the next, thus forming an endless coil, as shown in Fig. 10. The construction of such a ring armature would be as shown in Fig. 9. DIRECT-CURRENT DYNAMOS. 217 Qnrmnsp the rin<* shown in Fig. 10 with its endless winding to be rotated enter^he FK^ hand face of the ring are moving upwards, they will have an E. M. F. ge erated to them in one direction, while the E. M. F. in the conductors on the left lade will have an E. M. F. in the opposite direction, because all the conductors on this side are moving downwards, or in the opposite direction, to those on the other side. These two opposing E. M. F.’s will meet at a, as shown by the arrowheads, and will neutralize each other so that no current will flow through the windings of the armature. Suppose, however, that taps are connected a£ the points a and a', as shown by the dotted lines, and these taps connected to two rings r, r', mounted so as to revolve with the armature. By allowing brushes b, b f to press on these rings, we can make Fig. 10. connection with an outside circuit d, which may consist of a number of lamns or any other device through which we wish to send a current. By nuUiL in the taps at a and a', we have allowed the two opposing E. M. F.’s to set up a current through the common connections to the S thence trough the outside circuit. Current now flows in each halt of the armature winding, unites at a, flows out by means of ring r and brush b , thence through the outside circuit d to brush b and ring r, from whence it nasses to a ' and thus completes the circuit. When the ring 1 ?^ es a revolution from the position shown in the figure, it is seen that the current in the ouside circuit will flow in the opposite direction. In fact, an arrange- ment of this kind would deliver a current t^wouldte it would be what is known as an alternating current. Instead of simply bringing out two terminals to rings, suppose the winding to be tapped at a fairly large number of points, and connections brought down to a number of insulated strips, as shown in Fig. 11. If the armature be now revolved, it is seen that the brushes will come in contact with successive bars and keep the outside circuit in such re- lation to the armature winding that the current will always flow through it in the same direction . Moreover, if the num- ber of divisions in the armature be large, the current will fluc- tuate veiv little, being nearly as steady as that obtained from a battery. The arrangement made up of insulated bars is called the commutator, because it commutes or changes the relation of the outside circuit to the armature winding so that the current in the outside circuit always flows in^the same direction. All practical machines used for the generation of direct current must be provided with such a commutator. When alter- nating currents are used it is only necessary to use plain collector rings, as y -vAAAAAf* Re. Fig. 11. 218 DYNAMOS AND MOTORS. shown in Fig. 10. The foregoing brief description will give a general idea as to the construction of an ordinary direct-current dynamo or motor. Drum- wound armatures are more frequently used than the ring type shown, but the action is the same in either case. Factors Determining E. M. F. Generated— A dynamo should be looked upon as a machine for maintaining an electrical pressure rather than as a machine for generating a current. A pump does not manufacture water — it merely maintains a head or pressure that causes water to flow wherever an outlet is provided for it to flow through. In the same way, a dynamo maintains a pressure, and this pressure will set up a current whenever the circuit is closed, so that the current can flow. The important thing to consider, therefore, is the E. M. F. that the dynamo is capable of generating. The E. M. F. generated by an armature depends on the total number of magnetic lines cut through per second by the armature conductors. This means that, in the first place, the faster the armature runs, the higher will be the E. M. F.; in the second place, the greater number of conductors or turns there are on the armature, the higher will be the E. M. F.; and in the third place, the stronger the magnetic field, the higher will be the E. M. F. The E. M. F. in terms of these quantities may be written = nCN 100,000,000’ where n = speed in revolutions per second; C = number of conductors oh face of the armature; N = number of magnetic lines flowing from one pole. The constant 100,000,000 is necessary to reduce the result to volts. This equation enables us to make calculations relating to any two-pole dynamo, and with slight modification it is applicable to machines with field magnets having a number of poles. It will not be necessary to consider this formula further here, as the main thing to fix in mind is that the E. M. F. is propor- tional to the three quantities: speed, number of conductors, and strength of field. Field Excitation of Dynamos.— In the earliest form of dynamo, the magnetic field in which the armature rotated was set up by means of permanent magnets. Permanent magnets are, however, very weak compared with electromagnets, which are excited by means of current flowing around coils of wire wound on a soft-iron core, as shown in Fig. 13. As soon as the current ceases flowing around the coils of an electromagnet, the magnetism almost wholly disappears, but a small amount, known as the residual magnet- ism remains.* It is to this residual magnetism that the dynamo owes its ability to start up of its own accord and excite its own field magnets. When the armature is first started to revolve, a very feeble E. M. F. is gener- ated in it, but the armature is connected to the field coils in such a way •that this small E. M. F. is able to force a small current through the field coils, and thus set up a larger amount of magnetism in the field. This in turn increases the E. M. F. in the armature, and the building-up process goes on rapidly until the dynamo generates its full pressure. There are three different methods in use for supplying the field coils with current, and con- tinuous-current. dynamos are divided into three classes, according to the method used for exciting their fields. These three classes are: (a) Series- wound dynamos; (6) shunt-wound dynamos; (c) compound- wound dynamos. SHUNT- WOUND DYNAMOS. 219 fa'* Series-Wound Dynamos.— In this class of machine, the field coils are connected in Series with the armature, and all the current that passes through the armature also passes through the field and the outside circuit. This arrangement is shown in Fig. 12, where JS and 6’ represent the poles of the magnet, B and — B the brushes, and Re the outside cir- cuit, which may consist of lamps, motors, or any other device in which it is desired to utilize the current. It will be noticed that with an arrangement of this kind, the E. M. F. will increase as the current increases, because the field will become stronger and the speed is sup- posed to remain constant. This will be true up to the point where the field carries all the mag- netism it is capable of, or, in other words, until it becomes saturated. After this point is reached, the E. M. F. will increase very little with increase of current. In most ot the work connected with lighting or power trans- mission, it is desirable to have the voltage „ pri - P Q method of remain nearly constant. For this reason therefore, the senes method ot “^erator^whic^it^s been 6 applied at all ? e “®™Uy i£ Regulator of motors. , (b) Shunt-Wound Dynamos.— This style of machine has n0 \ largely of late years, although it was formerly very co^on Its use t present confined more particularly to machines of smal hv nass to the method of excitation, the field is connected as a sh unt ; or .by pass to me ormatnrp* i p the field winding is connected in parallel with tne armature. ?e“^^ current flows th rou|h £ Halt shows \he connections for this kind of field excitation An adpt SS& the dynamo is well designed, the pressure at more or^kS mately constant. The pressure will, however, always fall off more or less, on account of the drop in the armature, due to fh£ field the tendency that the current m the armature has of weakening tne e . The shunt winding is used quite largely for motors. />\ Pom nound -Wound Dvnamos.— 1 The compound-wound dynamo is the one most largely used for direct-current power and light distribution, and it is so SSsette winding used forfeiting ^ » a««ntagtonofft| «pri p 1- 250 Volts H ow y oils Fig. 16. that the energy represented by the product of the current and the drop through the resistance is converted into heat, and is thereby wasted, therefore, for great variations in speed, this method is not economical, though often very convenient. . , . at t? mo The applied E. II. F. may also be varied by varying the E M. F. of the generator supplving the current, but this can only be done iv here a single generator is supplying a single motor, or several motors, all oe varied at the same time; so that this method is only used in special CRS6S If ’the strength of the field is changed, the speed necessary to give a cer- tain counter E. M. F. will also be changed, which gives a convenient method of varying the speed. If the strength of the field is lessened, the speed will increase* and if the field is strengthened, the speed will decrease With shunt motors, the field may be weakened by inserting a suitable resistance in the field circuit, as in shunt dynamos; with senes motor* 3 the same result mav be obtained by cutting out some of the turns* of the field coils or by placing a suitable resistance m parallel with the field coils. This method of regulation Is also of limited range, since it is not econom- ical to maintain the strength of the field much above or betow a certain density. The resistance method described above being rather more it is generally used. For special cases, such as street : railroad work, various special combinations of the above methods of regulation are used. One of the most common of these is known as the series-parallel method, and is the method of regulation generally used at present for operating street cars. This method is equivalent to the method of cutting down the speed by reducing the E. M. F. applied to the motor, and is only applicab e where at least two motors are used. It is also used, to some extent, m haulage plants. When a low speed is desired, or when- the cm to be started up the motors are thrown m series, as shown in Fig. 16, thus making ?he voltaV across each motor equal to one-half lines, and cutting down the speed accordingly. When a high speed is CONNECTIONS FOR MOTORS. 223 Trolley -SOOVoltSr Fig. 17. Ground desired the motors are thrown in multiple, as shown in Fig. 17, and each motor runs 6 a? 1 full 1 speed because it gets the full ine pressure. ^ practice, ctartino- resistances are used in connection with the above to maKe me startini smooth but the two running positions are as shown, the motors beiim connected in series in the one case, and in parallel in the other. C®nnXn S tr Crntin U ou S .Curr ? nt Motors.-Fig. 18 shows the manner n which a shunt motor is connected to the terminals + and — ot the circuit. It will be seen that the current through the shunt field does not /TWTT'' — — pass through the resistance R KAAAJ which is connected in the arma- ture circuit. This is necessary, since to keep the field strength constant, the full difference of potential must be maintained be- tween the terminals of the field weak field that an excessive current would be required to turnisn ine ,ie Whtn’ connected afshown! hZcver, the field is brought up to its full strength before any curreiU passes through the armature; so this difficulty d °fin?e fnfseries motor the same current field coils, the starting resistance may be placed l in any part trf “e^ciM ^fhe'tffe terminlds 1 ? the motor nC6 ^ " f To C reverse^ the either Urn direction of the field or the direct™ of the armature. It is usual to reverse the direction of the current ; in tne a ture a switch being used to make the necessary changes in the conne Ctl rS!l~ l on chows the connections of one form of reversing switch Two “nTLpplied with "a 1 h^nd^e^^^d t the e two^ar^ ^Sn^togethe? by®a “ft c are^Sanged’on't^e'base* of SK&? eS& bars B and B l may rest either on a and b, as shown by the full c as shown by the dotted lines. The line is connected to the terminals T and T n , and the y motor armature between a and b, or vice versa, a an be ^“elwttehfsm^the position shown by the full lin^ r is connected 224 DYNAMOS AND MOTORS. between c and a. The direction of the current through the motor armature, or whatever circuit is connected between a and b , is thus reversed. In order to reverse only the current in the armature, the reversing switch must be placed in the armature circuit only. Fig. 21 represents the connec- tion for a reversing-shunt motor (a) and a reversing- series motor (6); + and — are the line terminals; R, the starting resistance; B and B\, the brushes of the motor, and F \ the field coil of the motor. Some man- ufacturers combine the starting resistance and revers- ing switch in one piece of apparatus. In connecting up motors, some form of main switch is used to entirely disconnect the motor from the line when it is not in use. To prevent an excessive current from flowing through the motor circuit from any cause, short strips of an easily melted metal, known as fuses, mounted on suitable terminals, known as fuse boxes, are placed in the circuit. These fuses are made of such a sectional area that a current greater than the normal heats them to such an extent that they melt, thereby breaking the circuit and preventing damage to the motor from an excessive current. The length of fuse should be proportioned to the voltage of the circuit, a high voltage requiring longer fuses than a low voltage, in order to prevent an arc being maintained across the terminals when the fuse melts. If desired, measuring instruments (ammeter and voltmeter) may be connected in the motor circuit, so that the condition of the load on the motor may be observed while it is in operation. All these appliances, regulating' resistance, reversing switch, fuses, instruments, etc., are placed inside the main switch; that is, the current must pass through the main switch before coming to any of these appliances, so that opening the main switch entirely disconnects them from the circuit, when they may be handled without fear of shocks. ALTERNATING-CURRENT DYNAMOS. An alternating-current dynamo is one that generates a current that periodically reverses its direction of flow. It was shown in connection with Fig. 10 that an armature provided simply with collector rings produced an alternating current in the outside circuit. This current may be represented by a curve such as that shown in Fig. 22. The complete set of values that the current or E. M. F. passes through repeatedly is known as a cycle. For example, the values passed through during the interval of time represented by the distance a c would constitute a cycle. The set of values passed through during the interval a b is known as an alternation. An alternation is, therefore, half a cycle. The number of cycles passed through per second is known as the frequency of the current, or E. M. F. Alternating-current dynamos are now largely used both for lighting and power transmission, especially when the transmission is over long distances. The reason that the alternating current is specially suitable for long-distance Fig. 22. ALTERNATORS. 225 work is that it may be readily transformed from one pressure to another. We have already seen that in order to keep down the amount of copper in the line, a high line pressure must be used. Pressures much over 500 or 600 volts cannot be readily generated with direct-current machines, owing to the troubles that are likely to arise due to sparking at the commutator. On the other hand, an alternator requires no commutator or even collecting rings, if the armature is made stationary and the field revolving, as is frequently done. Alternators are now built that generate as high as 8,000 or 10,000 volts directly. If a still higher pressure is required on the line, it can be easily obtained by the use of transformers, to be explained later. It is thus seen that where power is to be carried over long distances, the alternating current is indispensable. _ . . , , Alternating-current dynamos, like direct-current machines, consist ot two main parts, i. e., the field and armature. Either of these parts may be the revolving member, and in many modern ma- chines the armature, or the part in which the current is induced, is the revolving member. Fig. 23 shows a typical alternator of the belt-driven type, having a revolving armature. It is not unlike a direct-current machine as regards its gen- eral appearance. The number of poles is usually large, in order to secure the required frequency without running the ma- chine at a high rate of speed. The frequencies met with in practice vary all the way from 25 to 150. The higher frequencies are, however, passing out of use, and at present a frequency of 60 is very , common. This frequency is well adapted both for power and lighting pur- poses. When machines are used almost entirely for lighting work, frequen- cies of 125 or higher may be used. The frequency of any machine may be readily determined when the number of poles and the speed is known, as follows: ' number of poles v , rev. per min. Frequency = t> X ^ • For example, if an eight-pole alternator were run at a speed of 900 R. P. M., the frequency would be 8 _ 900 2 / = — x ^77 = 60 cycles per second. 60 Alternators may be divided into the two following classes: (a) Single* • phase alternators; ( b ) Multiphase alternators. , , (a) Single-Phase Alternators.— These machines are so called because they generate a single alternating current (as represented by the curve shown in Fig. 22). The armature is provided , with a single winding and the two terminals are brought out to collector rings, as previously described. Single- phase machines have been largely used in the past for lighting work, but they are gradually being replaced by multiphase machines, because the single-phase machines are not well suited for the operation of alternating- current motors. . „ , , .. ( b ) Multiphase Alternators.— These machines are so called because they deliver two or more alternating currents that differ in phase; i. e., when one current is, say, at its maximum value, the other currents are at some other value. This is accomplished by providing the armature with two or more distinct windings which are displaced relatively to each other on the armature. One set of windings, therefore, comes under the poles at a later instant than the winding ahead of it, and the current in its winding comes 226 DYNAMOS AND MOTORS. to its maximum value at a later instant than the current in the first wind- ins. In practice, the two types of multiphase alternator most commonly used are (1) two-phase alternators, (2) three-phase alternators. Two-phase alternators are machines that deliver two alternating currents that differ in phase by one-quarter of a complete cycle; i. e., when the current in one circuit is at its maximum value, the current m the other circuit is passing through its zero value. By tapping four equidistant points of a regular ring armature, as shown in Fig. 24, and connecting these points to four collector rings, a simple two-pole two-phase alternator is obtained. One circuit connects to rings 1 and T , the other circuit connects to rings 2 and ft It is easily seen from the figure that when the part of the winding connected to one pair of rings is in its position of maximum action, the E M F in the other coils is zero, thus giving two currents m the two different circuits that differ in phase by one-quarter of a cycle or one-half Three-phase alternators are machines that deliver three currents that differ in phase by one-third of a complete cycle; i. e., when one current is flowing in one direction in one circuit, the currents in the other two circuits are one- half as great, and are flowing in the opposite direction. By tapping three equidistant points of a ring winding, as shown in Fig. 25, a simple three- phase two-pole alternator is obtained. Three mams lead from the collecting rinsrs In order to have three distinct circuits, it would ordinarily be necessary to have six collecting rings and six circuits; but this is not necessary in a three-phase machine if the load is balanced in the three different circuits, because one wire can be made to act alternately for the return of the other tU< Uses of Multiphase Alternators— Multiphase alternators are coming largely into use, because, by using them, alternating-current motors can be readily operated. By using multiphase machines, motors can be operated that will Fig. 24. Fig. 25. start from rest under load, whereas with single-phase machines the motor has to be brought up to speed from some outside source of power before it can be made to run. For this reason, such machines are used for the operation of modern power-transmission plants. As far as the general appearance of three-phase machines goes, they are similar to ordinary single-phase alter- nators^ the only difference being in the armature winding and the larger number of collector rings. The multiphase alternator is also-adapted tor the operation of lights, so that by using these machines, both lights and motors may be operated from the same plant. They are well adapted for power-transmission purposes in mines, especially for the operation of pump- ing and hoisting machinery, because the motors operated by them are very simple in construction and therefore not liable to get out of order. ALTERNATING-CURRENT MOTORS. Alternating-current motors may be divided into two general classes: (a) Synchronous motors; (5) Induction motors. .. '(a) Synchronous motors are almost identical, so far as construction goes, with the corresponding alternator. For example, a two-phase synchronous motor would be constructed in the same way as a two-phase alternator. alternating-current motors. 227 They are called synchronous motors because they always run in synchro- nism, or in step, with the alternator driving them. This means that the motor runs at the same frequency as the alternator, and if the motor had the same number of poles as the alternator, it would run at the same speed, no matter what load it might be carrying. This type of motor has many good points, and is especially well suited to cases where the amounts of power to be transmitted are comparatively large and where the motor does not have to be started and stopped frequently. Multiphase synchronous motors will start up from rest and will run up to synchronous speed without aid from any outside source. They will not, however, start with a strong starting torque or effort, and will not, there- fore, start up under load, and can- not be used in places where a strong starting effort is required. For this reason synchronous motors are not suitable for intermittent work. (6) Induction motors are so called because the current is induced in the Fig. 26. because the current is induced in me , „ hrsW55 armature instead of being led into it from some outside eS mle hin^i a typical induction motor. There are two essential parts ^n .these ! machines, viz the field into which multiphase currents are led from the line, and me armature in which currents are induced by the magnetism set up by the field .SherWe^SS may be the stationaryorrevolvmg member but in most cases the field, or part that is connected to the hue, is stationary. Fig. 27 shows the construction of. the stationary member or field. This con sists of a number of iron laminations, built up to n ?titu«nff with slots around the inner periphery. Theform- woundcoils constitu ting the field winding are placed in these slots and connected the mains. This winding is arranged in the same way as the ar ^ a ture nse absent phase alternator. When the alternating currents _differing in .phase are through the winding, magnetic poles are the constant changing of the currents causes these poles to shift around the ring, thus set- ting up what is known as a revolving magnetic field. This armature, Fig. 28, consists of a laminated iron core provided with a number of slots, in each of which is placed a heavy copper bar b. The ends of these bars are all connected together by two heavy short- circuiting rings r, r running around each end of the arma- ture. The bars and end rings thus form a number of closed circuits. When such an arma- ture is placed in the revolv- ing field, the magnetism will cut across the armature con- ductors, inducing E. M. F.’s in them, and since the conduc- tors are joined up into closed circuits, currents will flow in mmr them. These currents will react on the field, and the armature will be forced to revolve. Such an armature will not run exactly in synchronism, because if it did, it would revolve just as fast as the magnetic field, and there would be no cutting ot i 228 DYNAMOS AND MOTORS . tines of force. The speed drops slightly from no load to full load, but if the motor is well designed, this falling off in speed is slight. Induction motors possess many advantages for mine work. One of the chief of these is the absence of the commutator or any kind of sliding con- 1 tacts whatever. Such motors can vide the armature with a winding simils the terminals to collecting rings, so that armature circuit. therefore operate with absolutely no sparking— a desirable feature for mine work. The motors are also very simple in construction, and are therefore not liable to get out of order. They have an additional advantage over the syn- chronous motor in that they start up with a strong starting effort, and, in fact, behave in most re- spects like any good shunt-wound direct-current motor. They are used quite successfully for all kinds of stationary work, such as pumping, hoisting, etc., but so far have not been used to any great extent for haulage purposes. When these motors are used for purposes where a variable speed is required, it is customary to pro- r to that of the field and bring out resistance may be inserted in the TRANSFORMERS. Reference has already been made to the use of transformers for changing an alternating current from a higher to a lower pressure, or vice versa, with a corresponding change in current. Transformers used for raising the volt- age are known as step-up transformers; those used for lowering the pressure are known as step-down transformers. The transformer consists of a laminated iron core upon which two coils of wire are wound. These coils are entirely distinct, having no connection with each other. One of these coils, called the primary , is connected to the mains; the other coil, called the secondary , is connected to the circuit to which current is delivered. Fig. 29 shows the arrangement of coils and core for a common type of transformer. The secondary coil is wound in two parts S, S', and the primary coii, also in two parts P, P', is placed over the sec- ondary. C is the core, built up of thin iron plates. Fig. 30 shows a weather-proof cast-iron case for this transformer. When a current is sent through the primary it sets up a magnetism in the core which rapidly alternates with the changes in the current. This changing magnet- ism sets up an alterna- ting E. M. F. in the sec- ondary, and this second- ary E. M. F. depends upon the number of turns in the secondary coil. If the secondary turns are greater than the primary, the secondary E. M. F. will be higher than that of the primary. The relation between the primary E. M. F. and secondary E. M. F. is given by the following: Secondary E. M. F. = primary E. M. F. X ^ ecQn( ^ ar y ^ urns . primary turns Fig. 29. BATTERIES. 22 , , ^ ,, primary E. M. F. or, secondary E. M. F. = - — . — - — - . ’ . primary turns secondary turns . . primary turns . . , , The ratio — — z is known as the secondary turns ratio of transformation of the transformer. For example, if a transformer had 1,200 pri- mary turns and 60 Phase 1. Phase 2. lOOO V. P JLSSJJLSL * 1000 P* P' 3— 3 f 000 0006 F-J OOP- n secondary turns, its ratio of transforma- tion would be 20 to 1, Fig. 32. and the secondary voltage would be one-twentieth that of the primary. Transformers are made for a number of different ratios of transformation, the more common ones being 10 to 1 or 20 to 1. Of course, a transformer never gives out quite as much power from the sec- ondary as it takes in from the primary mains, because there is always some loss in the iron core and in the wire making up the coils. The efficiency 1000 V- p I -1000 V p' mwiim Fig. 33. |— *100 V — loo r- Fig. 31. C 5 lOO V — * of transformers is, however, high, reaching as high as 97$ or 98$ in the larger sizes. Transformers are always connected in parallel across the mains, and if they are well designed, will furnish a very nearly constant secondary pressure at all loads, when furnished with a constant primary pressure. Fig. 31 shows transformers connected on a single-phase circuit, Fig. 32 shows the connection for a two-phase circuit, and Fig. 33 shows one method of connection for a three-phase circuit. ELECTRIC SIGNALING. BATTERIES. Batteries are used for various purposes in connection with mining work, principally for the operation of bells and signals. The LeclancM cell is one that is widely used for bell and telephone work. It is made in two or three different forms, one of the most com- mon of these being as shown in Fig. 34 (a). The zinc element of this battery is in the form of a rod Z, and weighs about 3 oz. The other electrode is a car- bon plate placed in a porous cup and sur- rounded with black oxide of manganese, mixed with crushed coke or carbon. The electrolyte used in the battery is a satura- ted solution of sal Fig. 34, (a) 0 ELECTRIC SIGNALING. ammoniac. The E. M. F. of this cell is about 1.48 volts when the cell is in good condition. In another form of the cell, known as the Gonda type, the black oxide of manganese is pressed into the form of bricks and clamped against each side of the carbon plate by means of rubber bands. This cell will do good work if it is only used intermittently, i. e., on circuits where the insulation is good and where there is no leakage causing the cell to give out ^nrrpnt, mntinuouslv. If current is taken from it for any length of The simple bell circuit is shown in Fig. 35, where p is the push button, b the bell, and c, c the cells of the battery connected up in series When two or more bells are to be rung from one push button, they may be joined up in parallel across the battery wires, as in Fig. 37 at a and 6, or they may be arranged in series, as in Fig. 36. The battery B is indicated in each diagram by short parallel lines, this being the conventional method. In the parallel arrangement of the bells, they are independent of each other, and the failure of one to ring would not affect the others; but in the series grouping, all but one bell must be changed to a single-stroke action, so that each impulse of current will produce only one movement of the hammer. The current is then interrupted by the vibrator in the remaining bell, the result Fig. 36. BELL WIRING. e p V. Fig. 37. 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O oS d 03 03 pO d o 3 d ft ft >..2 d d f> o 3 a p o rj JL 03 « qj O 0 d JS 2 t: 03 ,dp d g o dig § 03 'S 2 d ft”d o 7 ^ ft ft oft O 03 232 ELECTRIC SIGNALING. si Fig. 40. being that each bell will ring with full power. The only change necessary to produce this effect is to cut out the circuit-breaker on all but one bell by connecting the ends of the magnet wires directly to the bell terminals. When it is desired to ring a bell from one of two places some distance apart, the wires may be run as shown in Fig. 38. The pushes p, p' are located at the required points, and the battery and bell are put in series with each other across the wires joining the pushes. A single wire may be used to ring signal bells at each end of a line, the connections being given in Fig. 39. Two batteries are required, B and B', and a key and bell at each sta- tion. The keys k, k' are of the double-contact type, making connections normally between bell b or b' and line wire L. When one key, as A:, is depressed, a current from B flows along the wire through the upper contact of k' to bell b' and back through ground plates G', G. When a bell is intended for use as an alarm apparatus, a constant-ringing attachment may be introduced, which closes the bell circuit through an extra wire as soon as the trip at door or window is disturbed. In the diagram, Fig. 40, the main circuit, when the push p is depressed, is through the automatic drop d by way of the terminals a, b to the bell and battery. This current releases a pivoted arm which, on falling, completes the circuit between b and c, establishing a new path for the current by way of e , independent of the push p. For operating electric bells, any good type of open-circuit battery may be used. The Leclanche cell is largely used for this purpose, also several types of dry cells. Annunciator System.— The wiring dia- gram for a simple annunciator system is shown in Fig. 42. The pushes 1, 2, 3, etc. are located in various places, one side being con- nected to the battery wire b, and the other to the 1 1 - • 7 ' IITlfll + Vl 77 071111111. Fig. 41. leadin ciator Fig. 42. , wire l in communication with the annun- irop corresponding to that place. A bat- tery of two or three Leclanche cells is placed at B in any convenient location. The size of wire used throughout may be No. 18 annuncia- tor wire. „ . 4 „ . A return-call system is illustrated in Fig. 41, in which there is one battery wire b, one return wire r, and one leading wire l , lo, etc. for each place The upper portion of the annunciator board is provided with the usual drops, and below these are the return-call pushes. These are double-contact buttons, held normally against the upper contact by a spring. When in this SELL WISING. 233 position, the closing of the circuit by the push button in any room, such as No. 4, rings the office bell and releases No. 4 drop, the path of the current in Fig. 43. this case being from push 4 to ct-c-d-e-f-g-B-h-b back to the push button. On the return sig- nal being made by pressing the button at the lower part of the annunciator board, the office-bell circuit is broken at d, and a new circuit formed through k as follows: From the battery B to g-m-r-n-o-a-c-k-p to battery, the room bell being in this circuit. A gen- eral fire-alarm may be added to this system, consisting of an automatic clockwork appa- ratus for closing all the room-bell circuits at once, or as many at a time as a battery can ring. When this system is installed, the bat- tery wire should be either No. 14 or No. 16. Four or five Leclanch6 cells are usually re- quired in this case. It will be seen that the connections are so arranged that the room bell will ring when the push in that room is pressed. If this be not desired, a double-contact push may be substituted, so that the room-bell circuit is broken at the same time that the circuit is made through the annunciator. This double push should be so connected that the circuit is normally complete through the bell, the leading wire being connected to the tongue, and the battery wire being connected to the second contact point, which is normally out of circuit. Telephones are also used for signaling and communicating purposes. It has been found that a first-class long-distance bridging tele- phone is the best type to use. Bridging tele- phones are so called because they are bridged or connected in parallel across the line, and are not connected in series. If one telephone should get out of order, the others are not likely to be disabled. Fig. 43 shows a com- plete bell annunciator and telephone outfit, MTft LEVEL SBD. LEVEL 234 ELECTRIC SIGNALING . Hoi it mg Engine House. p Battery. Surface. as installed in one of the anthracite coal mines of the D., L. & W. R. R. Co. It will be noticed that bridging instru- ments are used and that each bell in the shaft is provided with a return- call button. This bell wiring should be put up in a substantial manner, and it is best, if possible, to run all the wires down the shaft in the shape of a lead-covered cable. Another shaft-signaling apparatus is shown in Fig. 44, as used at the West Vulcan mines, Mich. Fig. 45 ilFS H 9 f -t‘ level to*-* level //'- Level /£tE level Fig. 44. shows a form of waterproof push but- ton used at the same mine. Fig. 46 shows the arrangement of flash signals as used in Montana. This consists of a switch cut into this main circuit at PROSPECTING. 235 L _ firS Fig. 47. each level of the mines. By pulling out the handle bar of the switch, the lights on this circuit can all be flashed at once, and by a properly arranged code 9f flash sig- nals, the system can be used for communicating between the surface to any part of the mine, and between different portions of the mine. A system of signaling by which signals can be sent to the engine room from any point along the haulage road is shown in , Fig. 47. The conductors a and 6, leading from the battery run parallel to each other along the roadside, and about 6 in. apart. A short iron rod, placed across the wires a, o, signals to the engineer, or by simply bringing the two wires together a signal may be sent. , . . When the engineer hauls from different roads, the signal- ing system should be supplemented with indicators, so that when the bell rings the indicator would show from which point the signal came, and in case several signals were given at the same time, the engineer should not heed any until the indicator shows that a complete signal came from one place. , . . . A system of signaling for showing whether or not a section of track is occupied by another motor is shown / 27S Lamp Circuit Fig. 48. Ma/ns /oo’ 200 f 300 * 400 SOO' in Fig. 48. White lights indicate a clear track and dark- ness an occupied section. A single-center hinge, double- handle switch at each signal station is used and a touch of Fig. 46. the handle throws the switch in the desired direction. The switches are placed in the roof, 4£ ft. above rails within easy reach of motor- man. Fig. 48 shows the connections. Each switch is provided with a spring (not shown in the figure) which, drawing across the center hinge, when the handles are in their central position, insures a perfect contact when the switch is inclined toward either the trolley or rail-terminal plug. PROSPECTING. The prospector should have a general knowledge of the mineral-bearing strata, and should know from the nature of the ledges exposed whether to expect to find mineral or not. He should also possess such a kno wledgeof the use of tools as will enable him to construct simple structures, and a sufficient experience in blacksmithing to enable him to sharpen picks and drills, or to set a horseshoe, if necessary. . , . . , ... Outfit Necessary.— The character of the prospecting being carried on will have considerable effect on the outfit necessary, which should always be as simple as possible. In general, when operating in a settled country, the outfit is as follows: A compass and clinometer for determining the dip and strike of the various measures encountered; a pick and shovel for excavating, and, where rock is liable to be encountered, a set of drills, hammer, spoon for cleaning the holes, tamping stick, powder and fuse, or dynamite fuse and cap; a blowpipe outfit; a small magnifying glass; an aneroid barometer for determining elevations, and a small hand pick; the latter should weigh about If lb., and should have a pick on one end and a square-faced ham- mer on the other, the handle being from 12 to 14 in. long. If the region under consideration has been settled for some time, there will probably be geological, county, railroad, or other maps available. 236 PBOSPECTISG. These mav not be accurate as to detail, but will be of great assistance in the work on account of the fact that they give the course of the railroads, streams, etc. When operating in a mountainous region, away from a settled country, and especially when searching for precious metals, the following materials, in addition to that already mentioned, may be required: A donkey or pony packed with a couple of heavy blankets, an A tent, cooking utensils, etc.;, a . supply of flour, sugar, bacon, salt, baking powder, and coffee, sufficient for at least a month. It is also well to take some fruit, but all fruit containing stones or pits should be avoided, as they are only dead weight, and every pound counts. For the same reason, canned goods should be avoided, on account of the laTge amount of water they contain. A healthy man will require about 3 lb. of solid food per day. Many prefer to vary the diet by taking rice, corn meal, beans, etc., in place of a portion of the flour. The additional tools necessary are an ax, a pan for washing gold ore, making concentrating tests, etc., and, in some cases, an assay furnace and outfit packed upon another animal. Where game is abundant, a shot- gun or rifle will be found useful for supplying fresh meat. In regions abounding in swamps it becomes necessary to operate from canoes, or to - take men for porters or packers, who carry the outfit on their backs or heads. These men will carry from 60 to 125 lb. Plan of Operations.— When the presence of mineral is suspected in a tract of land, a thorough exa min ation of the surface and a study of the exposed rocks, in place, may result in its immediate discovery, or in positive proof of its absence; or it mav result in still further increasing the doubt of, or the belief that, it does exist. The first procedure in prospecting a tract of land is to thoroughly traverse it. and note carefully any stains or traces of smut, and all outcrops of every description; and. whenever possible, take the dip and the course of the outcrop with a pocket compass. Any fossils should also be carefully noted, to assist in determining the geological age of the region. These outcrops are frequently more readily found along roads or streams than anv other place on the tract. In traveling along the streams, the prospector should pav particular attention to its bed and banks, to see whether there are any small particles of mineral in the bed of the stream, or any stains or smut exposed along the washed banks. If small pieces of mineral are found in the stream, a search up it and its tributaries will show where the outcrop from which the find came is located. When the ravines and vallevs are so filled with wash that no exposures are visible, and nothing is gained* bv a careful examination of them, the prospector must rely on topographical features to guide him. . _ Any gold present in the vein material usually remains in the float as free or metallic gold, but other valuable metals are often leached out. The fact that the float itself may be barren does not indicate that it may not have come from a very rich deposit, and hence it will often pay to follow barren float since the outcrop of the vein itself is often either entirely barren, low grade, or of a different nature from the deeper deposits. In cases where there are no outcrops or any other surface indications, it would become necessary to sink shafts or test pits, or to proceed by drilling. The absence of any indication of mineral in the soil may not prove that there is not an outcrop near at hand, for the soil is frequently brought from a distance, and bears no relation to the material underlying it. In like manner, glacial soil often contains debris transported from deposits many miles away; but such occurrences can usually be distinguished by the gen- eral character of the associated wash material. Frequently, the weathered outcrop of a deposit has been overturned or dragged back upon itself, so as to indicate the presence of a very thick deposit For this reason, anv openings made to determine the character of the material should be continued until the. coal or other mineral is of a firm character, and both floor and roof are well exposed. Sometimes, in the case of steeplv pitching coal beds, the surface may be overturned for a consider- able depth, so that it is difficult to tell which is the roof and which is the floor Usually, if Stigmariee are found in the rocks of one wall, it is supposed that this wall ’is the floor of the seam, while if Sigillariae. fern leaves, etc. are found in the wall rock, it is probably the roof of the deposit. These indi- cations are not positive proof, for both of these fossils may occur in either the top or bottom wall of a coal deposit, though they are usually found in the positions noted. Coal. clav. gypsum, salt. etc. usually occur m unaltered deposits, i. e., in rocks that have not undergone metamorphism. PROSPECTING. 237 The accompanying table gives the names of the various geological periods, both as they occur in America and their foreign equivalents, together with the name of the principal form of life during each period. The various terms employed in geology are defined in the glossary. 238 PROSPECTING. Mptals and metallic ores usually occur in rocks that have undergone MSSSBIE mmmm siT=^g^@gi SHIS &S5MS «FtKn d ih^K^ toward the top of the h f^l^¥ eTT{ice or indication of the outcrop of a to sink a shallow shaft above the terrace. importance have as yet 1> eSrB^^’& , a5KSai<^^i»« gs^s&'asr'pSEa: a [>y “ e P d ^ r ik o d fThe coal hat up to been found although the bulk ot the nest coai ^xma, up metamorphic regions con- s j| t£S > » jp-s-i&'K gassa A’g. vvp yp. ^^sa .ntq SMSS3SS&' "^cssrsisiSti* w. -»-» ■» frequently associated with beds or iron 01 ^ lly foU nd in mountainous ORE DEPOSITS . 239 economic products as coal, petroleum, building stone, clays, etc., but not often of the precious metals. The reason for this appears to be that the latter are commonly found to be associated with evidences of more or less heat. In the Rocky Mountains they are rarely found except where volcanic eruptions have at some time been active, or where the strata have been changed or metamorphosed and crystallized by heat. As metallic ore bodies occupy fissures and other openings in the earth’s crust, we must go to regions where the greatest disturbances and uplifts have occurred, accompanied by the greatest rending and contortions of the rocks, and eruptions of volcanic matter. As a broad assertion, we may say that the greater part of any mountain region is a prospecting field, with the exception of those areas we have restricted as unpromising. But over this wide area of more or less metamor- phosed and crystalline rocks, there are regions and localities where the precious metals have already been found, and others where on geological grounds they are most likely yet to be found, and those are generally where eruptive forces have been especially active, where once molten eruptive rocks are most abundant, and the disturbance and crystallizing of the strata most pronounced. _ Position of Veins and Ore Deposits.— Ores, as a rule, are to be looked for at the junction of any two dissimilar rocks, rather than in the mass of those rocks. However, there are many exceptions to this, where the mass of a decomposed dike or sheet of porphyry has been impregnated by free gold or gold-bearing pyrites, and the whole rock is practically a gold vein. In this mass, the richest gold is often found in a network of little quartz veins run- ning through the porphyry mass. Some of our richest gold mines are found in “ rotten,” decomposed, oxidized dikes and sheets of porphyry; but this is rarely the case with lead-silver ores, which frequent rather the lines of con- tact in limestones or in fissure veins in granite. The Cambrian quartzites a few years ago were rather avoided by the prospectors, their extreme hardness pre- senting great difficulties in mining, and from the fact that they were generally supposed to be barren. The late disco v- b eries of very rich gold deposits in them, and of similar deposits in quartzites of a later age, have drawn more attention to them. The gold has been found in a free state associated with oxide of iron in cavernous deposits, and in close prox- imity to eruptive rocks. In the granitic rocks, both gold and silver occur in fissure veins associated with pyrites, galena, etc. These fissures, occupied by mineralized quartz veins, may occur in the granite or gneiss alone, or be at the contact of these rocks with a porphyry dike. Veins in overflows of volcanic lava generally fill a fissure having a more or less steep inclination, penetrating the lava sheets, caused probably by shrinkage of the molten lava on cooling. These fissures, in some cases, are likely to be limited in depth to the thickness of the lava sheet. Where, in a few rare cases, the fissure has been traced down to the underlying granite or some other rock, it has come abruptly to an end. Underground Prospecting. — Frequently a seam or deposit becomes faulted or pinched out underground, and it is necessary to continue the search by means of underground prospecting. Underground prospecting is, to a large extent, similar to surface prospecting, the underground exposures being simply additional faces for the guidance of the engineer. In the case of coal beds or similar seams, if a fault or dislocation is encountered, the man- ner of carrying on the search will depend on the character of the fault. Where sand faults or washouts are encountered, the drift or entry should be driven forwards at the angle of the seam until the continuation of the formation is encountered, when a little examination of the rocks will indi- cate whether they are the underlying or overlying measures. In the case of dislocations or throws, the continuation of the vein may be looked for by Schmidt’s law of faults, which is as follows: Always follow the direction of the greatest angle. It has been discovered by observation that, in the majority of cases, the hanging-wall portion of the fault has moved down, and on this 240 PROSPECTING . account such faults are commonly called normal Jaults. For instance, ii the bed a b, Fig. 1, were being worked from a toward the fault, upon encoun- tering the fault, work would be continued down on the farther side of the fault toward d, until the continuation of the bed toward b was encountered. In like manner, had the work been proceeding from 6, the exploration would have been carried up in the direction of the greatest angle, and the continuation toward a thus discovered. A reverse fault is one in which the movement has been in the opposite direction to a normal fault. Espe- cially in the case of precious metal mines, where the material occurs as perpendicular or steeply pitching veins, faults are liable to displace the deposit, both horizontally and vertically, in which case it may be difficult to determine the direction of the continuation of the ore body; but fre- quently pieces of ore are dragged into the fault, and these serve as a guide to the miner, and indicate the proper direction for exploration. Where a bed or seam is faulted, its continuation can frequently be found by breaking through into the measures beyond, when an examination of the formation will indicate whether the rocks are those that usually occur above or below the desired seam. „ , , , .. . Prospecting for Placer Deposits.— Placers are fragmental deposits from water in which the heavier minerals have been concentrated in certain portions, usually next the underlying, or bed, rock. The materials that are recovered from placer deposits are metallic gold, tinstone, monazite, sand, or precious stones. Placer deposits are modern or ancient. Modern placers are deposits of washed material, or debris, in the beds or along the banks of streams that are either now in existence or existed in comparatively recent times. Placer deposits may also occur in deposits along the seashore. Ancient placers are fragmental accumulations, similar to the modern placers, which have been buried under accumulations of strata or flows of lava, and they may or may not have become consolidated into rock. At times, placers are very compact, owing to the presence of large quanti- ties of oxide of iron or calcium carbonate, or similar cementing material. Often, in the case of modern placers, the streams, or other sources of water that deposited the material, have changed their course so that the placer deposit is now high up in the benches bordering the streams, or, possibly even on the top of the present hills. Such deposits are commonly called bench deposits , while those along the sides of the streams below the high- water mark are called bar deposits , diggings , or placers. ..... Frequently, a large portion of the gold or other valuable material is found in pockets or irregularities in the bed rock, but the pot holes under waterfalls are frequentlv barren of gold, on account of the fact that the current there was sufficiently swift to wash everything out, either heavy or light. When the soil is saturated with water, the mass may partake of the nature of a semifluid through which the heavy particles of gold settle until they accumulate on the bed rock. . ^ . . When prospecting for placers, the miner examines the country for any indications of present or ancient watercourses in which the deposits ot placer material have been formed. He pans the dirt from any deposits dis- covered, to see if it contains colors (small particles of metallic gold). It colors are found, more extensive operations are in order, and hence he sinks to bed rock and examines the material thoroughly, to see if it contains a paying quantity of the valuable mineral. . e ^ .. . . The form of placer deposit in dry or and regions differs from that in regions where the rivers have a continuous flow, on account of the tact that the deposits are largely the result of sudden rushes of water partaking of the nature of cloudbursts*, hence the rich portions in the placer material are very irregular, and are rarelv situated on bed rock, but are usually found on any strata that formed the bottom of the ravine during the sudden rush of water. During the rainy season in arid regions, the surface soil is some- times softened for a few inches, so that it becomes practically a mud, and particles of gold that it may contain tend to settle to the bottom of the sott portion, thus rendering the surface barren. This barren surface may be subsequently washed away by the rain,' or blown away as dust during the dry season. The repeating of this process year after year results in. the removal of considerable of the original surface and the formation of a rich stratum iust below the grass roots. Prospectors in and regions, who have been used to operating in an ordinarily well-watered country, are frequently deceived by finding this rich ground so high up in the deposit, not knowing that it is no indication as to the value of the material at a greater depth. OEMS AND PRECIOUS STONES. 241 In many cases, in the arid regions the portion of the deposit upon bed rock is entirely barren. In like manner, frozen ground may play an important part in the formation and distribution of the values in placer deposits. Gems and precious stones are prospected for in a manner similar to that employed in searching for placer material, and are usually found in alluvial deposits, from which they are obtained by washing. In a few cases gems are found in the rocks themselves; as, for instance, diamonds in the hard matrix that occurs as pipes or chimneys in metamorphic rocks, and which, upon exposure to the atmosphere, becomes decomposed, so that the stones are easily removed. Some of the corundum minerals are found in lime- stone and metamorphic or crystalline rocks. Turquoise usually occurs in veins, the outcrop of which is stained with carbonate of copper. In most cases, it does not pay to extract gems from rock formations when the rock is extremely hard, owing to the fact that the gems are liable to become broken in separating them from the rock matrix. For gem prospecting, the following outfit has been recommended: A shovel and pick; two sieves, one of 2 or 3 meshes to the linear inch, and the other of 20 or more meshes to the inch (the coarse sieve should be arranged to fasten on top of the finer one for use together); a tub in which the sieves can be submerged in water; an oilcloth on which to sort the gravel; several stones and crude gems as a scale of hardness; a small pocket magnifying glass, and a dichroscope. In some cases, a portion of the outfit is dispensed with. The use of the outfit may be explained as follows: The tub is partially filled with water, the two sieves fastened together, and a shovelful of material placed in the upper one, when they are submerged in water, the large stones cleaned and examined, and all of the fine material worked through the upper sieve, which is then removed, the material on it examined and disposed of. The material in the fine sieve is then washed until free from clay, when a little jigging motion in the water will carry the lighter material to the top. The sieve is then quickly inverted and the material dumped out on the oilcloth, thus bringing the heavier stones to the top. The various pieces should now be examined with the magnifying glass, scale of hardness, etc., and the identity of any doubtful colored gems settled, by means of the dichroscope. Few precious stones are of sufficient specific gravity to be concentrated in distinct beds, like gold or tinstone, but they are usually fairly well concentrated and freed from much of the lighter worthless material. Value of Free Gold per Ton of Ore.— The accompanying table was prepared by Mellville Atwood, F. G. S., and its use may be explained as follows' If a 4-lb. sample of quartz be crushed, the gold separated by panning and Value of Free Gold per Ton of Ore. ( Risdon Iron Works.) Weight, Washed Gold. 4-Lb. Sample. Grains. Fineness, 780. Value per Oz., $16.12. Fineness, 830. Value per Oz., $17.15. Fineness, 875. Value per Oz., $18.08. Fineness, 920. Value perOz., $19.01. 5.0 $83.97 $89.36 $94.20 $99.05 4.0 67.18 71.49 75.36 79.24 3.0 50.38 53.61 56.52 59.43 2.0 33.59 35.74 37.68 39.62 1.0 16.79 17.87 18.84 19.81 .9 15.11 16.08 16.95 17.82 .8 13.43 14.29 15.07 15.84 .7 11.75 12.51 13.19 13.86 .6 10.07 10.73 11.30 11.88 .5 8.40 8.93 9.42 9.90 .4 6.71 7.14 7.53 7.92 .3 5.03 5.36 5.65 5.94 .2 3.36 3.57 3.76 3.96 .1 1.68 1.78 1.88 1.98 amalgamation, the quicksilver volatilized by blowpiping or otherwise, and the resulting button weighed, the value of the ore per ton of 2,000 lb. will 242 PROSPECTING. be found opposite the weight of the button. The values are given for fine- ness of gold varying from 780 to 920. . To determine the value of gravel, a 6-lb. sample will give the same results as that obtained from a 4-lb. sample of quartz, on account of the fact that 18 cu. ft. of gravel measured in a bank weigh 1 ton, or 2,000 lb.; hence, a cubic vard of gravel measured in a bank weighs 3,000 lb., and for this reason a sample one and one-half times as large as that required for quartz must, be taken. In case the gravel is of low grade, a sample ten times as large, or 60 lb., mav be taken, in which case the value opposite the weight of the button will have to be divided by 10. As an example, in the use of the table we may suppose that a button from 4 lb. of ore or 6 lb. of gravel weighs 3.8 gr., and that the fineness of the gold is 830. Opposite 3 in the table we will find $53.61 as the value of the button in dollars containing 3 gr. of gold, and opposite .8 we will find $14.29. The sum of these is $67.90, the value of the ore per ton, or the gravel per cubic yard. EXPLORATION BY DRILLING OR BORE HOLES. Earth Augers.— When testing soil or searching for placer gold, sand, soft iron, or manganese ores, and similar materials that usually occur compara- tively near the surface, hand augers may be employed to great advantage. A good form of hand auger consists of a piece of fiat steel or iron, with a steel tip, twisted into a spiral about 1 ft. long, and having four turns. The point is split and the tips sharpened and turned in opposite directions and dressed to a standard width, usually 2 in. The auger is attached to a short piece of 1" pipe, and is operated by joints of 1" pipe, which are coupled together witlr common pipe couplings. The auger is turned by means of a double-ended handle having an eye in the center through which the rod D&SS6S The handle is secured by means of a setscrew. In addition to the auger, it is well to have a straight-edged chopping bit for use in comparatively hard seams. This may be made from a piece of If" octagon steel, with a 2 cut- ting edge. The upper end of the steel is welded on to a piece of pipe similar to that carrying the auger. When the chopping bit is employed, it is necessary to have a heavy sinking bar, which may be made from a piece ot solid U" iron bar, fitted with ordinary 1" pipe threads ()n the ends. Pros- pecting can be carried on to a depth of from 50 to 60 ft. with this outfit. The number of men necessary to operate the rods varies from 2 to 4, depending on the depth of the hole being drilled. When more than 30 ft. of rods are in use, it is usually necessary to have a scaffold on which some of the men can stand to assist in withdrawing the rods. When withdrawing the rods, to remove the dirt, they are not uncoupled unless over 40 ft. of rods are in use at one time, and sometimes as many as 50 or 60 ft. are drawn without Un Percussion or churn drills are frequently employed in drilling for oil, water, or gas, and were formerly much used in searching for coal and ores, but, owing to the fact that they all reduce the material passed through to small pieces or mud, and so do not produce a fair sample, and to the fact that they can only drill perpendicular holes, they are at present little used in prospecting for ‘either ore or coal. . , , The cost and rate of drilling by means of a percussive or churn drill varies greatly, being affected much more by the character of the strata penetrated than is the case with the diamond drill. In the case of highly inclined beds of varying hardness, the holes frequently run out of line and be- come so crooked that the tools wedge, and drilling has to be suspended. For drilling through moderately hard formations, usually encountered in searching for gas or water, such as sandstones, limestones, slates, etc., the accompanying costs, from the American Well Works, Aurora, 111., may be taken per foot for wells from 500 to 3,000 ft. deep for the central or eastern portion of the United This cost includes the placing of the casing, but Cost of Well-Drilling. Size of Well. Inches. Cost per Foot. 6 $1.50 8 2.25 10 3.00 12 5.00 15 8.00 States at present (1900). not the casing itself. drilling or bore HOLES. 243 When drilling wells for oil or gas to a depth of approximately 1^0® ft^, usinff the ordinary American rig with a cable, the cost is sometimes reduced per foot i5r 6" or Sewells. Tto “ usually njpch ifjA mav be drilled in a single day, and at other times, when very hard to make more than from 1 to 2 ft. per ^ The diamond drill is the only form that has been universally successful in drilling in any direction through hard, soft, or variable material. Even rhp of the diamond drill, many difficulties present themselves, and KISS Mate is smt JSBftfswa a practice, Dy u. m ^ « > . *? ’ t econ0 mv to employ a machine of large When a large machine is operating small rods on light work, the ariner in which the feed is independent of the material being cut, as m the case th TheflrIt e K’^advantageous when drilling through variable. measures in sea?ch of fofrly firm material, which does not occur m very thm beds or seams On account of the fact that this class of feed insure© the maximum amount of advance of which the bit is capable in 1 rounl upland danger is that the core from any thin soft seam may be grouna up ana washed away without any indication of its presence having been given. The second class or positive gear-feed, if properly operated, requires somewhat greater skill but if used in connection with a thrust register, it ffi^s^ehaffi^in^rmation as to the material being cAit, andisespeciaHy useful when prospecting for soft deposits of ve y^ 1 ^J® T ^ t ^| ,1 rf ze of t he Size of Tools —The size of tools and rods, and consequently the size oi ine core extracted depends on the depth of the hole and the character of the materialTeing prospected. When operating in firm measures such as “nthracite coal, hardrock, etc., it is best to employ a rattw; small bU even when drilling ud to 700 ft., or more, m depth. For such work, a core oi U in. to 1* in. is usually extracted. The rate of driUing with a small outfit is verv much greater than with a large one, owing to i the fact _ that there is a small cutting surface exposed, and the rate of rotation of the rods can be much treater When prospecting for soft materials, such as bitummo coal valuable soft ores, or for disseminated ores, such as lead^copper, gold, silver etc it is best to employ a larger outfit and extract a core 2 or 3 in. in diameter, and sometimes even larger, even though a comparatively small ma D rift of 1S d ia m ond° d°r H?h d es^o/the divergence from becomes a serious matter. This trouble may b ® wito tools about the bit as nearly up to gauge as possible. . Core oarnfia wim spiral water grooves about them, answer this purpose very well if they are renewed before excessive wear has taken place. of tw0 Surveying of diamond drill-holes may be carried on f b ,y o ei ^ t rict Where methods, depending on the magnetic conditions of tte E F there is no magnetic disturbance, the system developed by Mr. -b. . MacGeorge of Australia, may be employed. This consists m introducing into the hole, at various points, small tubes containing ^lted gelat , which are suspended magnetic needles and small P^mmets. After t gelatine has hardened the tubes are removed, and J the angle s ^^between me center line of the tube, the plummet, and the ne e d ^ noted L’/ This methol the data from which the course of the hole can be plotted, lhismetnoa gives both the vertical and the horizontal dn.t. 244 PROSPECTING. Where there is magnetic disturbances the needle cannot be used, but a system brought out by Mr. G. Nolten, of Germany, has been quite exten- sively employed. In this case, tubes partly filled with hydrofluoric acid are introduced into the hole, at various points, and the acid allowed to etch a ring on the inside of the tube. After the acid has spent itself the tubes are withdrawn, and by bringing the liquid into such a position that it corre- sponds with the ring etched on the inside of the tube, the angle of the hole at the point examined can be determined. This method gives a record of the vertical drift of the hole only. The value of the record furnished by the diamond drill depends largely on the character of the material sought. The core extracted is always of very small volume when compared with the large mass of the formation pros- pected, and hence will give a fair average sample only in the case of very uniform deposits. The value of the diamond drill for prospecting may be stated as follows: More dependence can be placed on the record furnished by the diamond drill when prospecting for materials that occur in large bodies of uniform composition than when prospecting for materials that occur in small bunches or irregular seams. To the first class belong coal, iron ore, low-grade finely disseminated gold and silver ores, many deposits of copper, lead, zinc, etc., as well as salt, gypsum, building stone, etc. To the latter class belong small but rich bunches of gold, silver mineral, or rich streaks of gold telluride. The arrangement of holes has considerable effect upon the results fur- nished. If the material sought lies in beds or seams (as coal), the dip of which is fairly well know T n, it is best to drill a series of holes at right angles to the formation. If the material sought occurs in irregular bunches, pockets, or lenses, it will be necessary to drill holes at two or more angles, so as to divide the ground into a series of rectangles, thus rendering it prac- tically impossible for any vein or seam of commercial importance to exist without being discovered. Where the surface of the ground is covered with drift and wash material, it may be best to sink a shaft or drill pit to bed rock, and locate the machine on bed rock. After this, several series of fan holes may be drilled at various angles from the bottom of the pit. Owing to the upward drift of diamond-drill holes, the results furnished from a set of fan holes drilled from a single position would make a flat bed appear as an inverted bowl, or the top of a hill. On this account, it is best to drill sets of fan holes from two or more locations, so that they will correct one another. If fan holes from different positions intersect the same bed, a care- ful examination of them will usually furnish a check on the vertical drift of the holes. The cost and speed of drilling depend greatly on the formation being penetrated. As a rule, it is more expensive to sink the stand pipe than to do the subsequent drilling. Stand pipes may cost $5 or more per foot to sink, while the cost of drilling in firm rock varies from $0.50 to $2 per foot; in the case of difficult drilling, the cost may run over $4 per foot. Where a large amount of drilling has to be done, a fair average estimate for shallow holes up to 700 ft. deep would be $2 per foot, under such conditions as exist in most mineral districts of the United States. The cost of labor, fuel, etc., enter into the problem, and frequently affect it to a considerable extent. The rate of drilling varies considerably, but in firm rock an average of 1 ft. per hour, including all delays for changing rods, etc., would be a fair average up to 700 ft. Greater speed than this could be made in soft shales or sandstones, and somew T hat less in hard rock. The hardness of the rock affects the rate of drilling much less than does its character. A conglomer- ate rock containing loose pebbles that come out during the drilling, or a crystalline rock containing angular pieces that come out during drilling, will cause far greater trouble than the hardest material ever encountered in diamond drilling. The following tables will give some idea as to the cost of diamond drilling under various conditions. The cost of drilling 2,084 ft. of hole in prospecting the ground through which the Croton aqueduct tunnel was to pass is given as follows: 814 ft. of soft rock (decomposed gneiss), in w hich an average of 23.1 ft. per dav w 7 as drilled, at a cost of $1.15 per ft. 347 ft. of hard rock (gneiss), in which an average of 11.1 ft. per day was drilled, at a cost of $3.97 per ft. 923 ft. of clay, gravel, and boulders, in which from 6£ to 9 ft. per day were drilled, at a cost of $4.07 per ft. The average progress per day in drilling the entire 2,084 ft. was 10.2 ft per day. 245 1 DRILLING OR BORE HOLES. ^*5 In the Minnesota Iron Co.’s mines, at Soudan, Minn., the diamond drill is used for drilling holes from 10 to 40 it. in depth in the back of the stopes, practically all the work being done in iron ore. The average cost per foot of drilling 13,512 ft. of hole was $0.7703, which was divided as follows. Carbons Supplies, oil, etc JJJc Fuel ifc::::::::::::::::::::; o:^ Total $0.7703 The following tables give the cost of boring at two Ishpeming, Mich., mines: TABLE I. f 400| days setter at $3.00 $1,200.75 1 T , J 372 days runner at 2.25 837.00 Labor -j 2 3 oa days runner at 2.00 460.50 [ 4i days laborer at 1.75 7.85 j Carbon 68f carats at $15.144 .• Bits, lifters, shells, barrels, and repairs Oil, candles, waste, and supplies Estimated cost compressed air Total Cost. L $2,506.10 . 1,035.47 .. 433.81 128.09 374.60 Cost per Ft. $0,669 0.276 0.115 0.035 0.100 .. $4,478.07 $1,195 28 193 ft. Ullllt/U 111 lltJlIlall 646 ft. 986 ft. urnieu in ihiacu uic Drilled in dioritic schist Total drilling 1,921 ft. 3,746 ft. Number of 10-hour shifts drill was running, including moving and setting up - V?o «• Amount drilling per 10-hour shift II * TABLE II. Underground drilling W5 £* Surface drilling 5* Stand pipe sunk — 4/U Total distance run 7,959 ft. Actual drilling time underground 672 shifts Actual drilling time on surface "*2 shins Time of foreman, setter, moving, and stand-piping 1,314 sums Total time worked shifts Average progress per man per shift Average progress per drill per shift actually run- ning - Weight of carbon consumed - Distance drilled per carat of carbon consumed 3.70 ft. 8.95 ft. 111.00 carats 67.38 ft. Cost of carbon Cost of supplies and oils.. Cost of fuel Cost of shop material, etc, Pay roll Total cost Amount. $1,887.00 134.13 360.73 663.36 4,000.03 $7,045.25 Per Ft. $0,237 0.017 0.045 0.083 0.502 $0,884 246 PROSPECTING. Records of Cost per Foot in Diamond Drilling. A B C D E F G 11 / J K L M N O Labor .707 1.040 2.483 1.150 .581 1.615 1.030 1.720 1.189 1.284 .721 1.200 .939 .812 .984 Fuel .094 .270 .256 .019 .000 .216 .090 .214 .157 .339 .419 .329 .126 .182 .251 Camp account Repairs .... .373 .559 .789 .538 .295 .621 .384 .549 .516 .495 .519 .595 .644 .722 .636 .139 .110 .294 .171 .135 .144 .103 . .185 .154 .165 .040 .087 .138 .126 .116 Supplies . . . .034 .065 .039 .074 .023 .032 .011 ; .039 .048 .097 .020 .092 .076 .097 .088 Carbon .... .263 .658 .859 .860 .843 1.587 .934 ; .684 .684 .733 .227 .209 .553 .239 .330 Supt .239 .322 .628 .040 .063 .192 .140 .305 .259 .172 .347 .220 .106 .196 .199 Total . . . 1.849 3.024 5.348 2.852 1.940 4.407 2.692 1 1 3.696 3.007 3.285 1 2.293 2.732 2.582 2.374 2.604 A 5 holes, 1,066 ft. I Sandstone and marble. B 1 hole, 1,293 ft. Black slate and jasper. J C 3 holes, 478 ft. Jasper, very hard. K D 5 holes, 780 ft. Jasper, hard. L E 1 hole, 216 ft. Iron slates. M F 1 hole, 174 ft. Jasper and slate. N G 2 holes, 267 ft. Jasper and slate. 0 H 3 holes, 410 ft. Jasper. Average cost of total work of drilling 21 hoies. Total of 4,684 ft. 2 holes, 634 ft. Iron slates. 2 holes, 360 ft. Schist and jasper. 6 holes, 1,350 ft. Iron slates. 2 holes, 611 ft. Schist, jasper, and quartzite. 6 holes, 2,091 ft. Quartzite. Average cost of drilling 18 holes, 5,046 ft. The following figures, taken from a letter written by T. F. Richardson, Departmental Engineer of Dam and Aqueduct Department, Metropolitan Water Board of Boston, and published by the U. S. Geological Survey, are of interest, as they show the rate and cost of diamond drilling under certain conditions. The costs do not take into account depreciation of machinery nor losses of time in moving machines, etc. The machines employed in this work were a Badger drill, manufactured by the M. C. Bullock Manu- facturing Co., of Chicago, 111., and an S-510 drill, manufactured by the Sullivan Machinery Co., Claremont, N. H. The total amount drilled was 2,814 ft., the deepest hole being 286 ft. deep, and the average depths of holes about 60 ft. The amount accomplished per day was from 0 to 32 ft., the average amount being probably about 10 or 12 ft. per day. The cost of drilling varied very largely, both with the hard- ness of the rock and the condition of the rock as to being seamy. The following was the cost of drilling 321.2 ft. of rather hard, tough diorite rock: Labor $341.25 Diamonds 74.30 Coal 17.50 Total $433.05 Cost per foot 1.34 (86.6 ft. of this was drilled with a If" bit, and 237.6 ft. was drilled with a U" bit.) Drilling 150.7 ft. of very hard syenite rock: Labor $158.00 Diamonds 298.69 Coal 10.50 Total - $467.19 Cost per foot ' 3.10 (Size of drill, 1$ in.) 1 drilling or bore holes. 247 The following was the cost of drilling 286.1 ft. of soft schist rockt^ Labor.. 87/75 Diamonds 11.50 Coa !n';zv *m25 Cost per foot (Size of drill, If in.) The following figures will be of considerable interest, owing ; to the fact that the work is practically all of the nature of sinking stand pip.es the Cost of operation per month of bed-rock exploration: TThtpiti Tl HpXOU.UU 6 laborers, at $1 ! 50 per day, 28 days 234.00 lcook 1— $429.00 240 rations, at 60 cents. - - 144,00 Total repairs, pipe and lumber for one party for 10 months ■•••••• 5UU * UU Total commissary charges for team, teed, dOU.UO Total simdry incident^ Total supervision hm.w Totals 10 months $2,070.00 2 ^ 000 Sundry expenses per month Total cost per month 803.00 10 months, at $803 jymuu Total number of feet sunk ^254.20 Total cost 2 4 g Cost per hole, 7,227 -s- 52 154 42 The drills were purchased second-hand from the Nicaragua Canal Co^, and the other apparatus was new. If the ongmai cost of all this machinery were distributed over the work, the results would be as follows. Machinery Total cost $9,63 2 86 Or average cost per foot Both machines are still in good repair, after having been used in Nicara- gua and in various localities in Arizona and California. . .. g xhe total depths penetrated in all materials at the various dam sites are as follows : The Buttes ... Queen Creek. Riverside Dikes San Carlos ... Total Covering. 1,621.2 357.8 729.8 80.0 143.2 2,932.0 Rock. Total. 196.0 1,817.2 55.6 413.4 40.2 770.0 0.0 80.0 30.4 173.6 322.2 3,254.2 248 PROSPECTING . Fig. 2. Magnetic Prospecting.— Bodies of magnetic iron ore are frequently discov- ered or located on account of their magnetic properties. Two forms of compasses are employed in this work: the dipping needle, or miners’ compass, and the ordinary compass. The ordinary compass is used to find the center of magnetic attraction in the horizontal plane, and after this has been found the ground may be run over with the dipping needle, to locate the center of attraction by this means. The ordinary compass does not give good results when operating over a mag- netic deposit, but is only useful in determining its outside edge, and thus locating its general position. The dipping needle differs from the ordinary compass in that the needle is hung in a vertical plane in place of horizontally, so that the needle is free to assume any position varying from the horizontal, depending on the downward component of magnetic attraction at that point. The vertical magnetic component at the point should be compensated for by balancing the dipping needle so that it will ordinarily stand horizontally when not affected by local disturbances. The actual work of prospecting may be carried on as follows: If there were an outcrop of a vein of magnetic material, as shown in Fig. 2, covered with a capping of wash material, the preliminary prospecting would be carried on as shown in Fig. 3, the dipping needle being carried backwards and forwards zigzag across the deposit, noting the point of maximum dip in each case and establishing a stake there as indi- cated by the crosses. After these stakes had all been established, an average straight line would be struck through them that would follow the course of the deposit as nearly as possible. Stakes would be placed at the ends of this line, as at X and Y, and the line X Y divided off into 100' dis- tances by means of stakes marked A , B, etc. Lines at right angles to the original line would then be turned off at these 100' points, and stakes placed every 10 ft. upon the branch lines. These points on the branch lines would be lettered with small letters, corresponding to the large letter on the line X Y, as shown in Fig. 4, which represents the obser- vations taken at the first station. The dip would be noted at each one of the 10' stations, and recorded in the note book. A convenient method of keeping the notes is to have a vertical line down the center of the page for the line X Y, and other vertical lines to the right and left of it for the indi- vidual stations 10 ft. apart, each side of the main line, the horizontal lines across the page being lettered A, B , etc., the sta- tions to the right and left being marked with primes and subscripts of the small letters corresponding to the line. After the observations have been taken, lines may be drawn through points of equal dip and equal deflection (isogonic lines). By this means the general form of the bed is determined. The maximum dip, in the case of an inclined deposit like that shown in Fig. 2, would occur at c, over the hanging wall of the outcrop, the dip at b being consider- ably less, and the dip at a being less than that at b. After the center of magnetic attraction has been discov- ered, prospecting may be continued by means of the diamond drill, or by sinking shafts or test pits. Sometimes, where deposits of magnetic iron ore have been eroded, the sands near the surface may contain such a considerable amount of magnetic disturbance as to indicate the presence of a body of iron ore. while in reality there may be such a small quantity disseminated through the sand that it could not be made to pay for its removal. Fig. 3. GEOLOGICAL MAPS AND CROSS-SECTIONS. 249 Any body of magnetic iron ore is affected by polarity, and one end of it will attract one end of the dipping needle, while the other end will attract the opposite end. Where the body is badly broken up, this dip oi the needle may be reversed several times in a comparatively short distance. Prospecting for Petroleum, Natural Ga3, and Bitumen.— Among the surface indications of petroleum and bitumen may be mentioned white leached shales or sandstones, shales burned to redness, fumaroles, mineral springs, and deposits from mineral springs. Also natural gas, springs of petroleum oil and naphtha, porous rocks saturated with bitumen, cracks in shale, and other rock partly filled with bitumen. Petroleum is never found in any Quantity in metamorphic rocks, but always in sedimentary deposits. Bitumen can be told from coal, vegetable matter, iron, manganese, and other minerals, which it sometimes closely resembles, by its odor and taste, also by the fact that it melts in the flame of a match or candle, giving a bituminous odor. (Iron and manganese do not fuse, and coal and vegetable matter burn without fusion.) Bitumen is also soluble m bisulphide of carbon, chloroform, and turpentine, usually giving a dark, black or brown solution. Frequently, springs or ponds have an iridescent coating ot oil upon the surface. Sometimes iron compounds give practically the same appearance, but the iron coating can always be distinguished from the oil py agitating the surface of the water, when the iron coating will break up like a crust of solid material, while the oil will behave as a fluid, and tend to remain over the entire surface even when it is agitated. , Frequently, bubbles of gas are seen ascending from the bottoms ot pools or creeks. These may be composed of carbureted hydrogen or natural gas, which is a good indication of the presence of petroleum or bitumen; they may be composed of sulphurated hydrogen or carbom c-acid gas. Garb - reted hydrogen can be distinguished by the fact that it burns with a yellow luminous flame, whereas sulphureted hydrogen burns with a bluish flame, and carbon dioxide will not support combustion, but, on the contrary, is a product of combustion. ,. ~ When carbureted hydrogen gas is discovered ascending from water, the bottom of which is not covered with decaying vegetation, it is almost a certain sign that there is petroleum or bitumen somewhere in the underlying or adiacent formations. „ _ , . ... , If natural gas or bitumen is found upon the surface of shale, it is probable that the material ascended vertically through cracks m these rocks from porous strata below; while if it is found in connection with sandstones it is probable that the material was derived from the porous sandstone itsell. This is especially liable to be true if the sandstone has a steep pitch. As a rule, deposits of bitumen or petroleum occur m porous formations overlaid by impervious strata, such as shales, slates, etc. Anticlines are more liable to contain such deposits, though they are not absolutely neces- sary to retain them, as at times portions of the underlying porous strata have been rendered impervious by deposits of calcium salts, silica, etc., ana hence the petroleum or bitumen will be confined to the porous portmns. Natural gas also occurs under similar conditions, but usually in anticlines Construction of Geological Maps and Cross-Sections.— After the surface exam- ination of a property is complete, the data should be entered on the best map procurable, or a map constructed. The scale depends on the size of the property, the complexity of the geological formation, the value of the property, and the material to be mined from it. The amount of work that it will pay to put on the survey will depend largely on the value ot the property, more detail being justified in the case of high-grade properties. If a property 1,200 ft. X 3,000 ft. (the size of four U. S. mining claims) were to be surveyed and mapped with a scale of 1 in. equal to 100 ft., the map would be 12 in. X 30 in. A vein of strata 10 ft. wide on this map would appear as T « ot an inch wide, which is about the smallest division that could be shown with its characteristic symbol; for greater detail, a larger scale, or larger scaled sheets of the most important portions of the deposit, will be necessary. If the geologist constructs the topographical contour map, he can take notes on the geology at the same time. When the l^undanes of the property are being surveyed, certain points should be established, botn vertically and horizontally, as stations in future topographical work. If the map is on government surveyed land, the government lines may be used for horizontal locations, but it will be necessary to determine the elevation of the different points. If the property is much broken, it is well to run a 250 PROSPECTING . few lines of levels across it, to establish points from which to continue the work. This work is usually done with a Y level and chain, the other details being subsequently filled in with a transit and stadia, the levels of the other points being taken either by using the transit as a level, by vertical angles, by bar- ometric observations, or by means of a hand level. Where lines of levels are run across the property in various directions, it is best to run them in such a direction that they will cross the strike of the strata as nearly at right angles as possible, so that the profile thus de- termined may be used in constructing a cross- section. Sometimes, for preliminary work, simply a sketch map is all that may be neces- sary. All of the outcrops and exposures, together with their proper dip, should be entered on the map. To Obtain Dip and Strike From Bore-Hole Records.— Before the results obtained from bore holes are available for use in map construction, the dip and strike of the various strata must be ascertained. The process, in the case of stratified rock, is as follows: If three holes were drilled, as at A, B, and < 7 , Fig. 6, each intersecting a given bed, the strike and angle of dip of the bed may be obtained by reducing the results from the three holes to a plane passing through the highest point of intersection, which is at A. The hole B intersected the bed at the distance Be , and C at the distance Cd below the point A. By continuing the line CB indefinitely, and erecting two lines Be and Cd perpendicular to it, each representing the distance from the hori- zontal plane through A to the intersection of the strata, two points in the line de are obtained, which line intersects CB produced at/; / is one point in the line of strike through A. In order to find the angle of dip, the perpendicular Cg is dropped from the deepest hole C unon the line of Fig. 7. strike Af. The distance Ch, equal to Cd , is laid off at right angles to Cg , when the angle Cg li gives the maximum dip. The results obtained from bore holes may thus be reduced to such form that the dips can be projected on the surface to obtain the line of outcrop for each stratum. Bore holes also furnish data for constructing underground curves in cross-sections of stratified rocks, and in locating the probable outline of ore bodies in other formations. SAMPLING AND ESTIMATING AVAILABLE MINERAL. 251 -r-r • r»« thp man all exoosures, whether surface or those lines ran, op, gr are '^ontours. M the g| s s ^ L b eds or deposits would be seam the crost ^cfion must he taken along the u “« P€^dioulw to the surface >of the cross-section .u i noi a i th p s . section> on this cross-section, accordingT^their SpM'S co'nsiderZe danger of exaggerating their tl * i fn e m a r!s''” t hVIu wwsed course of the beds should he sketched in, the property ^ ei ^ 0 “ e l should be tied to monuments or natural iSSSsSfe r Si ss gg^gSTfiSfiSSSSHaSSS material as it will be extracted the coal, shSuld be a«ta Sr3e° When may^lira te'^ay^^nd^n^wag^obtm^^later^or th^different^^ples BffigMBBBi which may be described as follows. , throwing each shovel- ful^ to'r'fpe^oY^co'nr Vl^h^he Sne'mly le reduced by 252 PROSPECTING. scraping it down with a shovel, passing slowly around it. If the amount of material is small, a flat plate may be introduced into the cone, and the pile flattened by revolving the plate. The pile is then divided into quarters by drawing lines across it. After this, two alternate quarters are scraped out and shoveled away, and the other two quarters are left as the sample. The process may be repeated until the block has been sufficiently reduced. In shoveling away the discarded portions, care should be taken to see that the fine dust under them is brushed away also, as they often contain fine and valuable mineral that would unduly increase the value of the resulting sample. When the sample consists of only a few pounds, it may be reduced by means of a riffle. Large samples consisting of several tons are sometimes sent to sampling works to be reduced by automatic sampling machines. If the property being examined is a mine in active operation, samples may be taken from the working faces, and also from cars, loading chutes, etc. Usually the samples from the face are kept separate from those from the cars and loading chutes, the latter being intended as a check on the former. In the case of ores of the precious metals, large samples are sometimes taken and used for mill runs. Stock piles, or dumps, may be roughly sampled by taking pieces from intervals over the surface, being careful to obtain a fair avenge of coarse and fine material, and of rock and ore. These samples are quartered djwn and assayed, but if a close valuation is d esired, it will be necessary to drive cuts or tunnels through the mass, and to take a certain amount, as every fifth or tenth shovelful, for the sample. When sampling dumps of fine material (as, for instance, tailings) it is possible to take samples from the pile by means of a drill, an auger 1 in. or 2 in. in diameter usually being employed for this purpose. The human factor always plays a large part in the value of a sample as finally selected, and hence it should be taken by a man who has had con- siderable experience in this class of work. For this reason, it is best to employ a mining engineer. One not accustomed to sampling very rarely undervalues a property, owing to the fact that it seems to be human nature to pick up a rich piece of ore or coal, rather than the barren gangue material or slate. When only surface exposures or shallow prospect openings are available, it is impossible to determine the amount of ore in sight, or to form more than a guess as to the size of the deposit. It is not safe to count any ore in sight unless it is exposed on at least three faces. Ore that is exposed on one or two faces can be counted as probable ore, while slight exposures can be counted only as chances indicated. The amount of material available in coal deposits can be estimated much closer than in the case of ores. If a seam is penetrated by a number of bore holes, or by workings extended over a considerable area, it is fair to esti- mate that the material will run practically as exposed for a considerable area; but especially in the case of bituminous coal, it is a comparatively easy matter to form some estimate as to the amount of material available. When dealing with ores, it is impossible to form reliable estimates, owing to the fact that horses or other masses of rock may be exposed at any point, and the ore bodies themselves are usually very irregular, hence it will be necessary to do careful blocking out before making anv estimates. When estimating the amount of mineral available, only that portion which can actually be removed in stoping should be counted, and if the seam is so narrow that it is necessary to break material from the walls, or if there are masses of country rock that have to be removed with the ore, the expense of removing them should be estimated and deducted from the value of the ore. DIAGRAM FOR REPORTING ON MINERAL LANDS. The following diagram will be useful as a guide in making out a report on a mining property: 1. Situation and Sur- roundings. { 1 . 2 . Name, i Distance 1. Location, if on surveyed land. 2. Nearest town or village. 3. Mineral district. . 4. County, state, or territory. and direction from one or more points. REPORTS ON MINERAL LANDS. 253 DIAGRAM FOR REPORTING ON MINERAL LAN DS {Continued). f 1. Hills or mountains. . , 2. Topogra- I 2. Character of surface, vegetation, and timber. phy. 1 3. Streams and water supply. L 4. Elevations. 3. Geology. 1. Struc- ture. 1. Rocks. 2. Axes. 3. Faults. 4. Dikes. { 5. Horses. 2. Geological period. 3. (a) Coal f 1. Number, beds. \ 2. Thickness, 1. Stratified. 2. Crystalline. 3. Igneous. Anticlines or synclines. 1. Number. 2. Strike. 3. Dip. 4. Throw. 1. Number. 2. Strike. 3. Dip. 4. Filling. 5. Throw. 1. Number and size. 2. Location. 3. Material. I or (5) Ore bodies. 1. Veins. 2. Beds or lenses. Reported. r 1 Reported. Averaee 3 ' J 2 ' Accordin « Aveiage. -j tQ meas , Umformity. y urement. Number. ^ Character. Strike. Dip. w . ,,, f 1- Maximum. Width. 1 2 Av erage. Vein filling. Ore chutes. Walls. Throw of walls. Number. Walls. Strike. Dip. Length. Height. Maximum width. Average width. 4. (a) Quality of coal, specimens, appearance in mine, in cars, benches. or , (6) Ore. ' l. Color, external, powder. 2. Luster. _ , . 3. Clearness from clay or sand, shale, 4. Sulphur. 5. Resin. . , . 6. Firmness, size of lumps, air slaking. 7. Cleavage or fiber. 8. Coking. 9. Color of ashes. . 10. Use: Gas, steam, domestic, forge, metallurgy. 11. Analyses or assays. : 1. Shipping. 2. Concentrating. 3. Metals or minerals. 4. Gangue. 5. Impurities. 6. Assays or analyses. 254 PROSPECTING. DIAGRAM FOR REPORTING ON MINERAL LAN DS — ( Continued). 4. Mining. 1. History. 2. Mine. ,’Y>- 1. Dates of opening, abandoning, reopening, number of mines and names. 2. Ownership. 3. Superintendence. 1. Shaft, slope, or tunnel. f 1. Total depth. 2. Extent of I 2. Depth below water level, workings, j 3. Number of levels. t 4. Extent of levels. 3. Water pumps, size, and kind, water cars, number and size, natural drainage. 4. Ventilation, natural, furnace, fan (for- cing or drawing out), sufficient or insuf- ficient. 5. Lighting, system used. 6. Powder, kind and grade used. 7. Explosive or noxious gases. 8. Coal-cutting machines and power drills. 9. (a) Mode of working, holding under, shearing, blasting, or wedging. 1. Underhand stoping. 2. Overhead stoping. ' 5. Rooming with or with- out timber. 6. Square sets. 10. Rooms, or stopes, pillars, dimensions, and general plan. 11. Timbering, timber trees. 12. Roof, or hanging wall, strong or weak, air slakes or not. 13. Floor, or foot- wall, hard or soft, creeps or not. 14. Roads, rails, and cars. 1. Men. 15. System of under- ground tram- ming. 16. System of hoisting 2. Mules. 3. Electricity. 4. Compressed air. 5. Wire rope. 6. Chain. 7. Locomotive. Cage. Skip. Cars. ■{I 5. Maps and Drawings. 1. Of the whole region. 2. Of the underground workings. 1. Cross. 2. Longitudinal. (1. General. 3. Columnar. < 2. Coal bed or other de- ( posit. 4. Buildings, works, or machinery. f 1. Scale. 2. North line, magnetic variations. 3. Date. 4. Maker. 5. Can buy, take, borrow, or have copied. 3. Sections. 5. Explanation. 6. Concentra- tion, 1. Hand picking. 2. Cobbing and picking. 3. Magnetic. 4. Mechanical, Siy. REPORTS OX MINERAL LANDS. 255 7. Coke Ovens. DIAGRAM FOR REPORTING ON MINERAL LANDS ( Continued ). 1. History, ownership, etc. 2. Number. 3. Character of ovens. 4. Dimensions. 5. Construction, materials, etc. f l. Charge, quantity, etc. 6. Operations. \ 2. Working. L 3. Discharging, quenching. 7. Repairs. .. , 8. Quality of product. (Assays, if any.) 9. Disposition of by products. 1. In heaps. 2. In stalls. 1. Roasted. 3. In kilns. 4. By mechanical calcmers. 5. Number &nd dimensions of roasters. ' 1. Base bullion. f 1. In shaft fur nace to 8. Metallur- gical Works and Treat- ment of Ore. 2. Smelted. 9. Disposition of Product. ' 1. Shipped. 2. Shipment. 10. Statistics. 2. In reverber- atory furnace to 3. In retorts to 1. As mined to 2. As concen- trates or coke. 3. Metal or matte to 1. Distance. 2. Roads. 3. Railroads. 4. Navigation, f 1. Capacity. 2. Matte. 3. Metal. 4. Number and dimen- sions of furnaces. 1. Metal. 2. Matte. 3. Number and dimen- sions of furnaces. 1. Metallic zinc. 2. Mercury. 3. Number and size of retorts. 1. Smelter. 2. Concentrator. 3. Sampling works. 4. Jobber at 1. Smelter or furnace. 2. Sampling works. 3. Jobber at 1. Refinery. , 2. Smelter. ^ 3. Jobber at 1. Production. 2. Labor. : f 1. Daily, weekly, or month- 2. Actual. , ^ in - to - nS - 3. Prices. i 2. Yearly in tons.* [3. Average. 1. Whole number of workers. 2. Number of workers in each class. 3. Number of horses or mules. 1. Timber. 2. Tools. 3. Fuel. 4 5 Oil. Powder. Day, different classes. Contract or piece, yard or ton. Porrip (rp 8. Local saies of product. r l. Machinery. 6. Labor, r. {* 9. Value of plant. 2. Buildings. 3. Roads, tracks, etc. 4. Rolling stock. 5. Supplies. 256 PROSPECTING. DIAGRAM FOR REPORTING ON MINERAL LAN DS — ( Continued), 11. Surface Plant. 1. Power plant. 2. Shops. 3. Powder houses. 4. Offices. f 1. Boilers. 2. Waterwheels. 3. Air compressors. 4. Steam and gas engines. 5. Electric plants. 1. Power for. 2. No. of forges. 3. Steam hammers. 4. Other tools. ” 1. Power for. 2. Saws. 3. Lathes. 4. Other machines. t 5. Benches and vises. 1. Power. 2. Lathes. 3. Planers. 4. Shapers. 5. Drill presses. 6. Other tools. 7. Benches and vises. 1. Smith’s shop. 2. Carpenter shop. 3. Machine shop. 5. Dry or change houses. 6. Storehouses. 7. Boarding and dwelling houses. 8. Stables. 9. Shaft houses. 10. Tipples. 11. Pockets or ore bins. 12. Company store. 13. Timber yard and plant for preparing timber. 1 Cifv nr com- L Q ualit y of water i. lAiy or com- n mercial * 14. Water. service. 2. Company service. Sufficient or in- sufficient. 3. Pressure. '1. Quality of water. 2. Sufficient or in- sufficient. 3. Gravity system. f 1. Direct. 4. Pump- ing sys- tem. Reser- voir or stand pipe. 15. Lighting. 1. Character. 2. Origin. 16. Hoisting or wind ing plant. 17. Surface trans- portation. 1. Gas. 2. Electric. 1. Commercial plant. 2. Company plant. Sufficient or insufficient. 1. Steam engines. 2. Compressed-air engines. 3. Oil or gasoline engines. 4. Electric motors. 5. Water motors. 1. Gauge. 2. Total length. 3. Size of cars. 4. No. of cars. 5. Power used. 6. No. of motors. r 1. Character and surface of. 2. Length. 3. No. of wagons and teams. 1. Size and capac- ity of. 2. No. of wagons for. 1. Railroad. 2. Wagon roads. 3. Traction engines. OPENING A MINE. 257 Diagram for reporting on mineral LANDS— {Continued). 12. Miscellaneous. 1. Yearly income, last year, or for any year. Netf S 2. Average cost per lb., or ton of material. [ 1. Quality of ore Or product. 1. Deposits ~ * * ^ of value. 13. Conclu- sions. 3. Merits of property. 4. Advice. 2. Amount of ore or f 1. Gross, material in sight. ( 2. Net. v 3. Value of material in sight. 2. Value of plant and works. 1. Mining. 2. Disposition of product. ^ 5. Local considerations. 1. Continue present system. 2. Change system to . 1. Ship as mined. 2. Concentrate, or coke and ship. 3. Smelt and ship. 1. Troubles. 2. Labor. 3. Supplies. 4. Climate. 5. Shipment facilities. 6. Markets. OPENING A MINE. The location of the surface plant and the mine opening depend on the formation of the deposit primarily, and secondarily on the facilities for transporting the product to market. It is impossible for bf\ ^ i* >.ax .2 X g g 4 ' b O V Oh W ^^a sas & 5 * * b ? ■|S x g;a * Z* * ■ b 02g ©1 p<£ a* CO CO t>. >» d c 3 3 © be bo ^ v - G r« § <® X -fi y^ o Too /3 oo^ be 2 ^ g-S6 ftsi 02 ^ M O ft g o' g bpbcS'SSo rj -H -H £ CM * © -gftft ft ' £ c 3 g d ft ft rift'd .a .a a ^ 2 ^ 83 O p aS o o ,3 ftftft° ©ftft™ ficot» b X b ►» o 3 £ ft a g ft tfl pH c 3 02 3 a ft 02 Tft 2o2 5 &c ag. $s' CO ft © ft a; 02 Nr. O* 05 CO CO CM ^5 o CO N O w ^ $®£ . 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Sic ft) 02 h ^ 02 ft ft ft 02 ft n 02 ft g g ^ 02 02 02 ft ft ftO V 02ft o 3 r O ft 02 'd g O 02 cO g c 3 3 8 02 -p'd S tiij g a; £ g g ft £ 6 d ft^be OTigS ’ a 2 §.s O 53 CO dSs a g 1—1 ft ft c3ft ft-n o g ft . : 02 !tP ; c3 : ft : $h ■ :«a.a * P CG be 02 «s g 9 & 5*5-51,8 2.S >5 g ft ft r ^rO O M as o t * H fec.g g > & *3 ft o 02ft V 02 ft a, 03 >, t-. s 3 02 t-t ft © u g 03 02 ftO * : Depth completed, 1,150 ft. tin the clear. 262 OPENING A MINE . are sealed or closed, and an inner tube introduced so that a freezing mixture may be caused to circulate down through the inner tube, and up through theouter tube. This freezing mixture may be either liquid ammonia gas, which is allowed to expand in the outer tube, or it may be a solution of calcium chloride that has previously been reduced to a very I9W tempera- ture by means of an ordinary refrigerating machine. The circulation is maintained in the pipes until the ground between them is frozen solid, after which the work may be continued as though the formation were solid rock, the material being blasted and hoisted in buckets. The freezing process mavTe applied to any wet formation, whether hard or soft while the pneumltfc process is applicable only to soft formations The. freezing process may be carried to practically any depth. As a rule, the freezing pipes are never sunk inside of the shaft area. , . The Kind-Chaudron method is applicable only to round shafts, and is suitable for shafts passing through very wet and at the same time com- paratively soft formations. The excavation is carried on by means of a large set of boring tools armed with steel teeth, and operated in a manner sinnlar to that employed in drilling wells by the percussive system first, a pit or shaft 4 or 5 ft. in diameter is drilled; this is followed by a reaming bit that enlarges the hole to the desired diameter, or the work may be accom- plished in three stages by using two reaming bits. The material removed by the first bit is hoisted out by means of a sand bucket, or sludger while that removed by the succeeding tools is hoisted out by buckets that are placed in the bottom of the first pit and kept there while the tools are m operation. No water is pumped from the shaft while it is being excavated or lined, and hence practically all the tendency that tbe s ]. des w . oul d have to cave is removed. After the shaft has been excavated down to and into a solid formation, it is lined by lowering cast-iron tubbing into the hole and making a tight ioint against the bottom by means of an expansive packing that is forced out by the weight of the tubbing, or lining. After the lining is m place the space between it and the sides of the excavation is filled with cement. When the cement is thoroughly hardened, the water is pumped from the inside of the lining, and men descend and examine the joint at bed rock. In this method, no workmen enter the shaft until it is lined through the troublesome formation. . Lone-Hole Process.— The long-hole process consists m the drilling of a series of diamond-drill holes over the area of the proposed shaft, then filling the holes with sand, after which the work progresses by removing the first 5 or 6 ft of sand from the holes in the interior of the shaft, charging these holes with explosives, and firing them by electricity. Next, the holes around the boundary of the shaft are charged and fired m the same manner, and the process is continued until the bottoms of the diamond-drill holes are reached. This method is especially applicable to work m hard rock where great speed in sinking is desired, for all the drilling is accomplished at one dperation, after which the sinking progresses by simply cleaning out the drill hole and blasting the material. General Comparison of Methods of Shaft Sinking. Where a shaft is sunk by forepoling, it is usually made rectangular in form. The pneumatic method mav be used for either round or rectangular shafts, and the lining may be either of metal or wood. The freezing process may be used for either round or rectangular shafts, and the lining may be either timber, metal, or masonry, as the entire opening can be left open until the solid rock is reached, when the lining can be built upon it. The Kind-Chaudron method is applicable only to round shafts, on account of the fact that the hole is bored. The long-hole process is applicable to either round or rectangular shafts, but .was originally introduced for sinking rectangular shafts. . Sinking Head-Frames.— Head-frames of very simple form are used for sink- ins The skeleton of the frame is formed of heavy squared timber (10" X 10" or 12" X 12") mortised and pinned together, and braced by diagonal braces. A good height from the surface to the center of the sheave is from 20 to 25 ft. The sheave should be from 6 to 8 ft. in diameter. The sinking bucket should be of boiler iron, or of heavy hard wood strengthened by iron bands, about 3 ft. in diameter at the top by from 2i to 3 ft. deep. It should be suspended bv a handle pivoted a trifle below the center, and it should have a pm on the rim of the bucket that will hold it in an upright position when a loose ring on the handle is slipped over it. A chain fastened to the top of the head-frame, with a hook on its loose end, is suspended so that when hang- ing plumb, it is over a chute leading to the dump car. As the bucket is SHAFT SINKING. 263 hoisted out of the shaft, this chain is attached, and the engine reversed. The bucket swings over the chute, the ring holding it upright is knocked off the pin, and the rock is dropped into the chute. Rocks too large for the bucket are suspended in chains and are hoisted in that way, and removed on a truck that runs on a track inside of the head-frame, the gauge of which is sufficiently wide to give plenty of clearance for the bucket. Sinking Engines.— Most shafts and slopes are sunk with old engines, or else by engines especially designed for such work, and so constructed that they can easily be moved from place to place. In some cases where an old engine can be readily had, it is set up on temporary timber foundations and used until the shaft or slope is finished, when it is replaced by the perma- nent engines, and the old one is dismantled and disposed of to the best a<1 Tod^— The old method of hand drilling is still adhered to in many instances, but it is gradually giving way to machine drilling, especially in deep shafts. When properly managed, the work is done much more rapidly and economically by the several excellent types of rock drills now on the market. They are constructed in a variety of shapes by the makers, and there are so many convenient accessories in the shape of fittings, etc. that all contractors prominent in the various coal fields possess one or more of their favorite type of drills. These drills are run either by compressed air, steam, or electric power, and in large shafts two are usually employed, so that work may not be delayed by a breakdown of one drill. The center or one side of the shaft is usually kept in advance of the rest, so as to furnish a sump for the collection of the water. The holes are drilled from 3 to 6 ft. apart, and the depth varies with the character of the rock. When a suf- ficient number of holes are drilled, the drill is removed, and a cartridge made of dynamite, dualine, or some other form of high explosive is tamped in each hole. These are all fired simultaneously by an electric battery, detonating caps being placed in each charge. To keep the shaft the required shape, if rectangular, a plumb-bob is sus- pended in each corner, either from the flooring on top, or from a beam laid across the cribbing, and these guide the miner in squaring the corners and sides. If the shaft is a circular one, a plumb-line is let down in the center, from time to time, and a rod cut the exact radius is revolved around it. If it strikes the rib, the miner knows that at that point the shaft is not true. Drainage and Ventilation.— When only a small amount of water is encoun- tered while sinking, the best plan is to allow it to collect in a depression and bail it from there into the bucket, hoisting it the same as the rock. Where the water is excessive in quantity, a steam pump is necessary. All the leading pump works make pumps especially designed for sinking purposes, and it is not in the province of this work to mention the advantages pos- sessed by one over the other. When the shaft is of moderate depth, a fire burning m one corner will supply ample ventilation. To rapidly clear away smoke, a good plan is to burn a bundle of straw or shavings in one end of the shaft, and throw a couple of buckets of water down the other end. When the shaft is very deep, or when the sectional area is small, ventilation is produced either by a steam jet, or by a small fan turned either by steam or by hand. In some cases, a fire is used that draws into a board pipe. Speed and Cost of Sinking.— Any attempt at a general estimate regarding the speed and cost of sinking is impossible, for many reasons appreciated by the practical miner. Shafts vary so much in size, and in the character of the material through which they pass, that even if there were no other items to be considered, a general estimate could not be made. But if the ground is pretty well known, and the sectional area and the depth given, the experi- enced contractor knows how much he can drive in a given time, and he can consequently form a good estimate for each separate shaft. The range of cost is so great that it may be anywhere from SI to S10 per cubic yard of material excavated. , . , . Slope Sinking.— A slope is an inclined plane driven down on the bed of the seam, and is generally through coal or ore, though sometimes they are driven through rock across measures to cut the seam that cannot be conve- niently worked bv a slope. In the latter case, it is merely an “inclined tunnel.” In the former it might be termed an “inclined gangway.” A slope and an inclined plane, when mentioned hereafter, will mean an inclined opening in coal or ore , used as a passageway for mine cars. When tne location of the slope has been decided on, erect a temporary 264 OPENING A MINE. sinking plant; an old engine is generally used. For a short distanee, varying with the nature of the ground, but usually ranging from 10 t<3 20 > ft. on the pitch, an open cut is made, and the earth, rock, or crop coal is town ^out by hand. As soon as sufficient cover is reached, the work of undermining and timbering is commenced, and at the same time a double or single track is laid, so that the material can be taken out in a car or self-dumping skip. When the latter is used, the track is continued up a trestle some distance above the surface, and a head-sheave so placed as to draw the skip up the required distance and dump the material in a chute beneath tke tres^mg. The width of the slope depends on the size of the cars and the number of compartments. The most common arrangement is to divide the slope into three compartments; two large ones for hoistways, and a smaller one for pump rod, column pipe, steam pipe, and traveling way. This last is also used as an airway while sinking is going on. In some instances, slopes have but one hoistway, laid with three ratio and a turnout at the middle of the hoist, and some have single track with a central turnout. This may be economy in first cost, but is uot ni the long run. Collisions are apt to occur, and the breaking of a rope or the falling ol coal from an ascending car is apt to cause more damage than when two C ° 1 When n Sveral lifts are simultaneously worked, a single-track slope is used; but unless the pitch is light and several cars can be hoisted at once, this method produces a comparatively small output. . , , , When the dip of a slope is under 40°, the height of the should be about 7 ft. in the clear. When the slope dips more than 40°, unless self- dumping skips or gunboats are used, a cage is necessary, and then the height must be made greater. . . , 4 , , n , „ QTw1 The sinking of a slope is similar to gangway driving, and the tracks and timbering are kept well up to the face. . . . „„ noTO j The timbering is very similar to gangway timbering, except that squared timber is more frequently used (but it is not necessary) and .^e jmito are cut with more care. On steep pitches, a heavy mud all is let into the nb on each side, to prevent the road from slipping down the pitch. The Sump.— When the shaft or slope is completed, among the necessary is a sump in which to collect the drainage of the mine. This is an openingTower in the vein, when it is a pitching one, or in the rock when it is a flat seam reached bv a shaft. It should be large enough to hold an\ excess of water that the pumps cannot handle; and the pumping machinery should be powerful enough to handle the ordinary drainage by running not over 10 hours per day. When this is the case, m an emergency, the pumps ran be run continuouslv, and thus handle the surplus w ater. Drivine the Gangway.— in bituminous coal seams, the height of the gangway is governed bv tlie thickness of the seam, and this is also true, m a certain sense in the anthracite regions. But in the anthracite regions thej are very Hfdom less than 6 ft. in height. In the larger seams they are ^m 6 ft 6 in to 7 ft. 6 in. high in the clear, and from 10 to Id ft. wide The gauge oftrack varies from 24 to 48 in. The grade should rise at least 4 in. in 100 ft., and a cutter 3 ft wide bv 18 in. deep should be cut in the coal on the low side. T f is gutter should be a gutter, and not a receptacle for refuse. There is no ecoSln a sMlow^tter/or in neglecting it ^n^t costs a few cents a dav to keep it open. Some authorities advise a rise of from 6 in. to 1 ft . in o V erV 100 ft., but thev evidently do not take into consideration that ^g^ a riSe means a loss of from 26 to 53 ft in lift at ££ lone or in other words, in the loss of from 68,000 to 13/, 000 sq. ft. of tne area LHoaT^o be reached by the gangway. This app lies to Puffing seams^ Where the seam is fiat, or nearly so, the gangway must, of course, be cmven on a grade that best suits the formation Turnouts oneach side of the shaft or slope, of a suitable length, are a necessity, if the slope or snait to be ke pt constantl v supplied with coal. These turnouts vary m length de^ndingonTe length of the cars, and the number necessary to keep the machinery in motion between trips. They should ^^? e enough^abffiw at least 3 ft. in the clear between the bodies of the cars, 5 ft. is even oette . When possible to avoid it, there should be no center props between the ^Levels in Metal Mines.— The cross-section of the level depends largely on the character of the ore mined, and the desired output from the deposit. In .i. _ mnfni minoc tytwI n pi n tr hi eh-grade mineral from narrow lixt; cuaiauici ui me uic , — ~ , the case of precious metal mines, producing high- veins, the levels are driven as small as possible. •grade mineral from narrow Immediately adjoining the MINE TIMBER AND TIMBERING. 265 shaft there is a plat or station the full width of the shaft. This is heavily timbered and provided with a double track, but, as a rule, the levels have but a single track, and in some cases there is but a single track at the shaft, there being a turnout or switch in the level a short distance from the shaft. In this class of mines, 5 ft. X 6£ ft. in the clear would probably be the average size of a level, it being driven as small as possible. In the case of mines producing lower grade material and handling heavy tonnages from large deposits, as, for instance, in some of the iron and copper mines, the levels are driven larger, and in some instances are double-tracked, being from 7 ft. to 8 ft. high in the clear, and from 7 ft. to 12 ft. wide inside timbers; but, even m this class of mines, in most cases single-track levels 7 ft. X 7 ft. to 8 ft. X 8 ft. in the clear are employed with turnouts or passing points at intervals, and a double or triple track at the shaft. The levels are usually driven with a slight grade away from the shaft, so that they will drain to the shaft, and the grade will be in favor of the loaded car. In some mines where electric tramming is employed, the levels are so driven that the motor makes a circuit through the mine, following the foot-wall in one direction, and returning along the hanging wall, or one of the drifts may be in the country rock. Such systems as this are employed only in large properties handling a very great tonnage. TUNNELS. Mining tunnels are usually of small cross-section compared with those that occur in railroad work, it being rare that their size is such that they cannot be driven in full section, and if the ground is firm the operation of placing the lining may follow behind the work of driving. They are generally lined with timber, and in case the ground is of a soft or treacherous nature, bridged square sets and forepoling are employed, with or without breast boards, as the necessity of the case demands. When the material is firm rock, the tunnel is sometimes not lined, the roof being given an arched form. The various forms of timbering employed as tunnel linings are shown in the sections on Timbering. MINE TIMBER AND TIMBERING. Choice of Timber.— Timber used for underground supports in mines should be long-grained and elastic, and, at the same time, should not be too heavy. Oak, beech, and similar woods are very strong, but are heavy to handle, and when set in place are treacherous, owing to the fact that they are short- grained and not elastic, so that, though strong, when they do break, they break without warning. Mine timber is placed, not with the intention of ultimately resisting the great pressure of the earth, but so that it may keep any loose pieces in place and also to give warning to the workmen, thus enabling them to escape before a fall occurs. For this reason, pine and fir are, as a rule, better for mine timbering, as they combine a fair amount of strength with considerable elasticity, and hence give warning long before they break. Very elastic timbers, such as cypress, willow, etc., are, as a rule, to be avoided, on account of the fact that they will simply bend like a bow, without offering the necessary resistance to hold the material in place for a short time. Preservation of Timbers.— The character of the ventilation in a mine has considerable effect on the life of any timber supports. Damp stagnant air will cause mold and fungus growth, which will be followed by the destruc- tion of the timber through decay or dry rot. All timbered openings should be well ventilated, and provision made for the speedy removal of damp hot air, such as commonly occurs around pump rooms and along steam lines.. Water is a good preservative, as it washes off the spores of the fungi as fast as they are formed, and sometimes shaft timbers are kept wet on account of the preservative action of the water. Timber may be also preserved (1) by a solution of common salt and water; (2) by impregnating the wood with such metallic substances as sul- phates of copper, iron, etc.; (3) by impregnation with the chloride of mag- nesium or zinc; (4) by creosoting; (5) by coal tar; (6) by carbolineum. A solution of 1 lb. of salt in 4 or 5 gal. of water gives a cheap and easily armiied preservative with which the timber should be thoroughly soaked. 266 MINE TIMBER AND TIMBERING. Sulphate of iron is economical and effective. In the zinc process, ablution of 1 gal. of liquid chloride of zinc (Sp Gr. 1.5) mixed with So gal. of is forced into the wood by pressure. Impregnation with crude CTe^ote oil is effective, but it has the disadvantage of making the timber very inflammable. Creosote acts in a threefold manner: (1) WAhsthe pores and prevents saturation by water; (2) it destroys organic life, ^ car- bolic acid that it contains coagulates the albuminoids and P r ^Y^^^cay. Painting with liquid tar is effective, but makes the wood, very mflMomable. Painting with ordinary whitewash is also said to give good results. Car- bolineum is said to be effective but is quite expensive. It is applied with a brush, or bv steeping in a tank; 1 gal. will cover 300 to 400 ft. of timber. Professor Louis, of England, has shown that preservatives decrease the strength of timber from 84 to 204, depending on the P^ce^used. The following table gives the results of tests made by different methods of treating wood at Saint Elroy, France, and recorded in 1890: Tests of Preservatives for Mine Timber. Relative Preservative Effect. Name of Preservative. Oak. Fir. 1 Pine. Beech. Birch. Poplar. Tar Chloride of 2 dnc Sulphate of copper Sulphate of iron Creosote 27.8 10.5 42.1 18.0 1.7 263.5 50.0 12.0 12.5 2.5 87.5 26.3 8.0 4.2 4.4 105.4 18.6 1.8 4.7 0.6 26.2 52.5 2.5 3.7 3.3 150.5 34.7 15.5 2.9 1.3 The simple removing of the bark, under some circumstances seems to be advantageous, but, in some woods, if the bark is removed, the sap ’wood should also be removed. In many cases, the sap wood of coniferous trees is as strong or stronger than the heart wood, and for this reason it should not be removed. Also, in the case of many coniferous trees, the bark seems to act as a protection to the timber in the underground workings. If it becomes necessarv to reduce the size of the individual sticks, it is usually better to split them than to saw them, especially in the case of wood from coniferous trees, as this does not destroy the sap wood or unduly injure the grain or fibers of the stick. Generally speaking, mine timbers last longer when kept wet, and, on this account, some of the mines m Europe have introduced a system of pipes for spraying the timbers m dry portions of the mine When timbers are alternately wet and dry, they are destroyed with amazing rapiditv. Timber should be probed from time to time to ascertain its condition, as’ timbers may appear sound on the outside when the heart is completely destroyed bv dry rot. In selecting props, the principal points to be observed are: Straightness, slowness of growth as indicated by narrow annular rings, freedom from knots, indents, resin, gum, and sap. They should also be well seasoned before use. With these ^cautions and proper mine ventilation, fungus growth may generally be obviated and durability ^Pladne of Timber.— The individual sticks should never be weakened by cutting mortise and tenon joints. The pressure should be evenly distributed over a number of sticks, and not concentrated or centered at one point. Centers of revolution should be avoided. The individual sticks should be placed in the direction of the strain that they are to resist, so thatthey will be subject to compression along their length rather than to a transverse strain J The individual sticks should be so placed, and the joints so formed, that the pressure tends to strengthen rather than weaken the stm . c ture up to the crushing strength of the timber. In the case of large tlie timber- ing should be done according to some regular system, while at the face of coal mines, single props or posts are usually found better, owing to the fact that “duty is only to support the loose portion of the roof for a lifted time. Probably the most important point is to timber in time, before the rock becomes broken or begins to settle. MINE TIMBER AND TIMBERING . 267 It seems generally agreed that the main weight in mines comes nearly at right angles to the bedding, and that the props should be mainly set in that direction. If the deposit is horizontal, the weight generally comes vertically; but if the deposit is inclined, the weight comes at a right angle to the inclina- tion. Some authorities hold it as a principle that all props should be set at a rectangle against the main pressure. Others, in order to guard against possible side thrusts and a tendency of the ordinary weight to ride to the dip m inclined deposits, purposely cause a sufficient number of props to be set slightly deviating from the common axis. Sawyer fixes a maximum and minimum slope for the props, varying with the rate of dip. He makes this maximum slope of the props one-sixth that of the dip, ana the minimum slope one-third of the one-sixth. Props are usually set with the butt end downwards, but not always. Hav- ing the butt end upwards adds a trifle to the weight on the lower end, but the larger size at the top should lessen the liability of its being split by a coupling resting on it, and also gives more surface for abrasion in hammer- ing up against a rough roof. Both ways may therefore have advantages according to the circumstances. The butt end downwards, with air circu- lating, is the way Molesworth recommends for stocking. Size of Timber.— The general tendency at all metal mines at present is toward the use of systematic frames composed of small sizes of timber, rather than toward the use of large individual sticks. The advantages are: (1) the small timber is cheaper and easier to procure; (2) it is easier to handle, and hence costs less to place in position. By making the frames according to some regular system, the individual sticks can be framed on the surface by machinery so that better joints are secured. The setting of timber can be done by less experienced help when it is all alike. Joints in Mine Timbering. — In all mine timbering, the object is to so form the joints that no fastenings will be necessary and that the shape of the pieces will be such that the pressure from the surrounding material will keep the joints tight. The reason for this is that any metal joints usually corrode rapidly in mines, and that, when it becomes necessary to replace timbering, this can be done with greater ease if the sticks are so framed that, by relieving them temporarily of the pressure from the sides and top, they can be simply lifted out of place and new ones substituted. The use of a framing machine renders it possible to frame the joints more exactly than with hand framing. With hand-framed timbers, the joints are always cut a little free to allow for any unevenness in the surface, but, if machine- framed, they are sure to be of the same size. As timber does not shrink in the direction of its grain, it is evident that where the posts meet, if the caps shrink slightly, they will become loose in the space between the shoul- ders; hence, if timbers are cut green and framed to the exact size, subse- quent shrinking may open some of the joints. This may be obviated by keeping the timber moist. . The method of taking timbers into a mine depends on the size and number of timbers used and on the character of the opening into the mine. In drift or tunnel mines, timbers are sent in on flat cars built especially for the purpose, or in the regular mine cars. In vertical shafts, they are usually stood on end on the floor of the cage, and lashed together and also to the supports of the cage. Where the opening is an incline, it is the common practice to load the timbers into a skip and thus lower them into the mine. Timber should, wherever possible, be framed on the surface. Undersetting of Props.— Props at the working face should not be set at right angles to the inclined floor of the seam, but should be underset, and the greater the inclination, the greater the underset. The amount of under- set should vary with the inclination of the seam, and should not be so great that the props will fail out before the roof has tightened them. Forms of Mine Timbering and Underground Supports. — The timbering of a mine maybe divided into two heads: (1) timbering the working faces; (2) tim- bering the roads. The roof may be supported (a) by packing the waste places entirely where sufficient material is obtainable for the purpose, and timbering the faces and roads; (ft) by partially packing the waste, by buildings or stone S illars with intervening spaces, and by timbering the face and roads; (c) y timbering the face and roads and supporting the roof in the waste places by wooden or stone pillars, but without any packing; ( d ) by timbering alone without any packs or walls whatever; ( e ) by supporting the main roads With brick arching, or by steel or iron supports. 268 MINE TIMBER AND TIMBERING. The accompanying plates include all the common forms of mine timber- ing and underground supports. _ . . . . Fig 1 shows a post a and breast cap b. The breast cap b is also sometimes called’ cap, head-block , headboard , lid, or bonnet Sometimes the posts are placed upon blocks of wood similar to the head-blocks or headboards, the block being called a sole; at other times, two or more posts may be set upon one long block of timber called a sill. When posts are used m inclines, they should not be set perpendicular to the foot and hanging walls, but should be underset slightly, so that any tendency of the hanging wall to settle will bring the posts nearer at right angles to the walls, and so tighten them- the amount of underset should never be more than one-sixth the Ditch’ of the deposit. Where posts are set at an angle, they are usually Dlaced on wedges, and, as the pressure comes on, the wedges are tightened Fig 2 represents a stull a, which is used either to keep the walls, of perpendicular or steeply inclined beds or veins apart, to support planking or lagging as a working platform, or as a platform upon which to pile or© or rock Fig. 3 represents cockermegs, which are simply timber frames employed in coal mines for holding the face of the coal in place while it is being undercut They are composed of a pole c extending along the face and supported by short stulls or braces a, the whole being tightened into place by the long stulls b. ...... „ .. , , Fig. 4 shows a crib, cog, chock, pillar, or shanty built up of timbers and filled with waste rock. It is intended to serve as a pillar and to withstand great vertical pressure, doing away sometimes with the necessity of leaving pil 7^is ^cribbing framed from round timbers laid skin to skin, and used in raises or ore chutes. , , . r , Gangway or Level Timbers.— Fig. 5 is a set employed m the case of an extra- wide gangway, there being a center post under the middle of the cap. This form of set may be provided with a sill when the floor of the drift or gangway s^so^ ^ form Qf drift set surrounded by bridging and used where such bad ground is encountered as to necessitate forepoling. A are the posts, B the caps, and C the sill of the regular set; D are upright bridge pieces; E a horizontal bridge piece separated from the set proper by blocks F so as to provide spaces H around the regular set through which the spiles or forepoles can be driven. , . , Fig 8 shows a form of drift set sometimes employed m very heavy or swelling ground. This method of framing the timbers shortens each piece and reduces the transverse strain on all the timbers. Fig. 9 shows an ordinary drift set provided with a sollar for ventilation purposes. An additional brace b is placed parallel to the cap c, and this is covered with plank lagging a, so as to provide a passage above the regular drift, which may be used as a return air-course. Fig. 10 is a simple form of drift set employed when the roof and walls are of soft material, but the floor material firm. It is composed of posts l, upon which is placed the cap c. The joggle cut into the cap to receive the heads of the post should never be less than 1 in. nor more than one-third the thickness of the cap. The cap is usually made of such a length that the posts l have an inclination or batter as shown in the illustration, thus giving greater strength to resist side pressure without decreasing the floor area of the drift, which may be necessary for drains, ditches, water pipes, etc. at the sides of the track. When the floor is not composed of solid material, the posts l may be set upon a sill that is framed to fit the legs in a manner similar to that shown for the cap. The joggle cut in the sill should never be less than 1 in. nor more than one-third the thickness of the sill. The sill is usually composed of lighter material than the cap, is flattened .on one or both sides, and is sometimes used as one of the ties to receive the t; rac k Fig. 11 shows a post l and the cap or collar c, used where one wall is of firm material. On one end the cap is placed in a hitch. When the collar is supported in a hitch, it is sometimes said to be needled, the operation being called “ needling.” The bottom of the post a is also secured m a hitch, in case there is any side pressure. To keep the surrounding material in place, lagging is necessary, as shown behind the timbers in Figs. 5, 10, and 11. In the case of running ground, the lagging is usually made from sawed material apd driven close together. MINE TIMBER AND TIMBERING. 269 270 mine timber and timbering. Fie. 13 illustrates a method of spiling or forepoling. a are the I*>sts of the regular set, b the caps, and e the top bridging. The front ends of the spiles from any given set rest on the bridging of the next advanced set, and the spiles for advancing the work are driven between the bridging and the set, as shown in the illustration. To force the spiles out into the ground, so as to provide room for the placing of the next set, tail-pieces i are employed, these are placed behind the back end of the spiles as they are being driven. After the spiles have been driven forward the desired amount^another set is placed, the tail-pieces knocked out, and the front end of the spiles allowed to settle against the bridging of a new set. Where the face is composed of extremely bad material, it may be necessary to hold it in place with breast boards , asshown at k, the breast boards being held in place hy props ^ which rest against the forward set. When breast boards are used, it is usually necessary to employ foot and collar braces between the sets, so as to transfer the pressure of the breast back through several sets. ^ Fig. 14 shows a method of placing drift sets m the case of very heavy or swelling ground, a are the posts, c the sills, b the caps, d are the collar braces that bear against both the caps and the posts, while e are foot oj hM braces that bear against both the sills and the posts; / are diagonal braces that are halved together and placed as shown. . . . , , Shaft Timbering.— Fig. 12 shows square-set timbering, sometimes employed for shaft lining. A are the wall plates, B the end plates, C the buntons, and D the posts. The method of framing the different parts is plainly Sh °Fig* 15 represents cribbing sometimes employed for shafts. It is composed of heavy sawed material halved together at the ends ^ pieces a are called wall plates , and the short pieces b end plates Between the compartments a partition is built up of pieces c called buntons The end of the buntons are let into the wall plates an inch or so, as shown m tne illustration and should be so placed that they will break joints with the individual pieces of' the wall plates, thus preventing the timbers of any 6in f g .1f, sh“ws l a^tfJr Method of ' framing. ^times em^oyed for the formed at I). This construction necessitates the cutting of a j^non onthe the Dost F as shown. S is a 2"X 2" strip nailed along the center of the back of the wall and end plates as a support f ^^c lag^ng tha is placed outside of the sets. The lagging is usually composed of 2 or 3 ^ 18 shows the use of hangers between the individual square sets. The it timber, to the sinking of a small prospecting mld^from wS,t^"ted down by about 45°. 272 MINE TIMBER AND TIMBERING . Landings Plats or Stations.— Fig. 22 is one method of timbering a pjat or station. The regular square-set timbering of the shaft is continued past the station and the heavy stull or reacher a put across at the bottom of the station. The posts b are bolted against the posts of the sets and the cap c placed on top of them. After this, the wall plates are cut out between the posts b and the station opened and timbered as shown in the illustration. The height of the station is gradually reduced to that of the drift or level COI Fig Ct 23 ^epresents a method of timbering a level in a slope where the ground is so firm that only stulls are employed m the slope and at the station the timbers all being secured in hitches or by stulls. a represents the stulls and c the timbers that are spiked to the stulls and carry the stringers for the car track, b represents the car track from the level that is brought across above the skip track. , . , Special Forms of Supports.— Fig. 24 shows a stone arch which as a stull RiiTYDorts the waste material in the level. . Fig. 25 shows a stone arch when one wall of the formation requires SU ^ig.*26 illustrates a passage lined by a combination of stone or brick walls with wooden caps and lagging for the roof. ' _ _ - . Fig 27 illustrates the lining of a drift or level supported by means of iron or steel shapes bent into the form of an arch and employed for the support of ^Fig^28 illustrates a cast-iron post or stull that has been successfully used as a support in mines. It is composed of two pieces a and 5, held together by a collar vC. By driving c down on the post, f |he two pieces can be taken a ^^Fig a 29 illus?rates a masonry shaft lining supported by means of cast-iron plates C set in bell-shaped cavities cut in the walls of the shaft. As the masonry of a section from below is built up toward that above, the over- hanging portion D is cut out a little at a time, and the masonry from below built up under the plate so that the lining becomes continuous. Fig 30 illustrates masonry shaft linings, supported by artificial stone or cement foundations built in bell-shaped cavities cut m the walls of the shaft. The blocks of artificial stone are provided with inclined bearings C, whicn serve to transmit a portion of the downward thrust of the lining in the direction^of the^a SuppQrts _ The use G f i r0 n or steel, either for vertical or horizontal supports in mines, has not become at all general. In America, timber is as yet comparatively cheap m most mining localities, but this situ- ation is fast changing and the timber reserves are be ^g rapidly cut off, so that many mines now using wood must, m the comparatively near future, resort to some other form of support. Some of the disadvantages ot metal supports are their greater initial cost, and on this account it is essen- tial that all such supports should be recovered. As very little timber is recovered in American mining, this objection is one toat ^1 proMbly co^ tinue. The mine water is often of such a character that it v ill dissolve iron or steel; particularly is this the case in copper mines, and ^ where there is much pyrites. Metal mines keep their shaft sets open but a short time compared with the pit bottoms of large coal mines, and hence the extra cost of metal construction is frequently not warranted. The dis- tricts in which metal mines are located are more likely to be disturbed than is the ground over a coal mine, and if timbering is crushed, it is much easier to repair than iron or steel. 'Another objection to metal supports is the fact that they cannot be as easily framed and worked as timber. On the other hand, the life of metal is, under ordinary circumstances, much greater than that of timber, and while the inital cost may be greater, whenever the metal can be recovered it can be used over and over again, and it always has a certain value as scrap iron or steel. After a metal beam has bent, it can still be used by simply turning ^ upside down Another advantage for steel is that it occupies less space than timber or masonry, and thus gives a larger effective area of roadway for the same cost of driving, or else the amount of excavation may be reduced. . Although metal has not been greatly used for props or upright supports, it has been quite extensively used, both in America and abrosm, for sup- porting shaft bottoms and landings, and m England it has been quite successfully used for cross-bars in timbering roads, the bar tong set upon wooden legs. In some of the European mines, a complete metal casing has MINE TIMBER AND TIMBERING. 273 been used. In locations where a constantly increasing pressure comes upon the roof, an elastic bending material must be used, and in such case, soft steel is greatly to be preferred to cast iron. 274 MINE TIMBER AND TIMBERING. Trestles.— Figs. 31 and 33 illustrate the various timbers and methods of cutting the joints for ordinary railroad trestles. In Fig. 33 the portion (a) at the left illustrates the manner of framing a pile trestle, while the portion ( b ) at the right represents the manner of placing timbers and cutting the joint for the framed trestle. Fig. 31 represents bents of a frame and pile trestle HEAD FRAMES. 275 and the side elevation of a low pile trestle. The various pieces in the figures are numbered, and the accompanying table gives the names of the parts. Fig 32 illustrates a bent of a frame trestle that is fastened together entirely by means of drift bolts, no joints whatever being cut. Figs 34 and 35 illustrate one manner of cutting the tenons and mortises on the ends of the batter braces and posts and frame bents, and also the drain holes that are bored in the mortise to prevent the timber from rotting. Usually the sills are notched or boxed to receive the ends of the timbers, in addition to having mortises formed in them. Figs. 36 and 37 show such joints for receiving the batter brace and post. . Fig 38 illustrates the manner in which a tenon is sometimes formed on the top of the pile to secure the cap. When the cap is secured by a tenon, the two are united by a wooden pin shown in the lower part of the figure, and known as a treenail. Fig. 39 illustrates a manner m which the cap may be placed upon a pile trestle by splitting the cap into two pieces, a and b with the tenon c the full width of the pile between them. . . . Fig. 40 illustrates the manner in which the cap is sometimes secured to a pile by means of a drift bolt, and Fig. 41 shows the manner in which the same thing may be accomplished with the use of a dowel. Figs. 42 and 44 show two methods of longitudinal bracing between the bents of the trestles for inclined planes, such as are used at breakers or concentrating mills. # _ , Fig. 43 is an elevation of a high trestle, showing the cross-bracing and framing of the structure. „ „ , • Timber Head-Frames or Head-Gears— Fig. 45 is the simplest form of head- gear, which consists of a vertical post to carry the weight of the sheave, etc., and a diagonal post that approximately bisects the angle between the rope from the drum and the rope hanging down the shaft, thus taking the resultant pull upon the axle of the sheave. There is usually some extra timbering, as shown, to support the cage guides and form a platform about the sheave for convenience in oiling. Fig. 46 shows a modified form of the same type of frame, in which the main upright leg is vertical and in which there is also another vertical Bent , Framed, 1. Bent, Pile, 2. Cap, 8. Cross-Tie, 4. Dapping , 5. Gaining, see Dapping, 5. Guard-Rail, 6. Jack-Stnnger, 7. Longitudinal Brace, 8. Mortise, 9. Mud Sill, 10. Notching, Gaining, Dapping, 5. Packing Block, 11. Packing Bolts, 12. Sill, 17. Stringer, 18. Sway-Brace, 19. Tenon, 20. Waling Strip , see Longitudinal Brace, 8. 276 MIKE TIMBER ASD TIMBERING. member on the opposite side of the shaft. The inclined leg is also braced and connected to the main vertical member. Fig. 47 is a head-frame for an inclined shaft where the ore pocket is in the structure carrying the sheaves. Such head-frames are sometimes enclosed 49 in their upper portions in a building so as to protect the men during winter. Fig. 4S is a form ot framing quite common in the anthracite coal fields of Pennsylvania, in which the timbers are further braced bv tie-rods, as shown. Steel Shaft Bottoms.— Fig. 49 is a shaft bottom fitted with steel supports, the posts being Z-bar columns and the caps being replaced by I beams, which, in the station proper, are supported on stone or brick walls. This metal construction is employed throughout all the portion of the bottom landing and passages where the cars are handled after they are brought from the workings or before they are returned to the workings. Undersetting of" Props.— The following table, from Sawyers “Accidents in Mines.” gives the maximum and minimum angles at which props should be set for varying inclinations. This table can be taken as a general guide, but it does n<7t take account of the length of prop nor the varying amounts of movement of the top rock under different conditions. METHODS OF WORKING. 277 Undersetting of Props. Rate of Inclination of Seam. Degrees. Angle or Underset of Props. Minimum Degrees. Maximum Degrees. 6 0 1 12 0 2 18 J- 3 24 1 4 30 2 6 36 2 6 42 2 7 48 3 8 64 and upwards 3 9 METHODS OF WORKING. No definite rules can be given for the selection of a method of mining that will cover all the conditions that may exist at any given mine. Each mine is a distinct and separate proposition, and each superintendent must judge how he will adapt the general principles here given to the local conditions at his own mine. Every system of mining aims to extract the maximum amount of the deposit m the best marketable shape and at a minimum cost and danger. OPEN WORK. Open work applies to the working of all deposits that have no overburden, or to those in which the overburden or overlying material is stripped from the portion of the deposit to be removed by hand, steam shovels, scrapers, etc. It includes particularly all quarries and placer workings, and can be applied to many mineral and coal deposits. The advantages of this system are that no timber is required; unprofitable underground workings do not have to be kept open and in repair; when required, a simple hoisting plant is used; there is less danger to the work- men from falls of roof and from blasting; there is practically no danger from fire; artificial lights are not required; mining can Be done more economically, as larger faces are open, larger blasts can be used, and the amount of work accomplished per miner is greater, and better superintend- ence can be had; the health of the men is usually much better when working in the open; the deposits can be more easily extracted and the ore more easily and more perfectly selected, and, under proper conditions, the output can be increased almost indefinitely. The disadvantages of open work are: A large amount of overburden often has to be removed and a place for sorting this waste material provided; the workmen are exposed to the weather; the expense of open work increases rapidly with depth of covering. Open work may be divided into two general classes: First, where the whole or a greater part of the deposit is of value and has to be removed, as in quarries and in ordinary mines; second , where the valuable portion is but a small part of the whole, as in placers or fragmental deposits carrying gold, platinum, etc. Deposits of the first class may be worked as follows: (a) The deposit is stripped, if necessary, and the material is removed by hoisting with derricks or a cableway, or by drawing out in cars with the use of underground passages. This class includes practically all quarries for building or orna- mental stone, slate quarries, and most of the open-pit and steam-shovel iron, phosphate, and similar mines. ( b ) The deposit is stripped, and drifts or tunnels are extended through the material below the surface, either from adjacent valleys or from shafts sunk outside of the deposit. The material, 278 METHODS OF WORKING. after being mined in the open pit, is thrown through openings to these drifts or tunnels, through which it is trammed to the surface or to the foot of the hoisting shaft. . „ . Steam -shovel mines are those in which the material is, when necessary, first shaken loose by big blasts of low-grade powder, and then loaded into railroad cars with steam shovels, which lift the ore from its natural bed and deposit it in cars to be taken directly to market or to a concentrating or washing plant. Mining is thus done very cheaply, but the steam shovel, from a mechanical standpoint, is not an economical machine and the costs of repairs are high. T he expense for hauling material from the steam shovel increases rapidly with adverse grades. Economy in steam-shovel mining depends on the shovel being kept constantly at work. An output of 2,000 tons per day for a steam shovel and one locomotive has been reached and even surpassed, but this cannot he taken as an average for a season s work. Under favorable conditions, there is probably no cheaper method of mining The cost of removing 97,854 yd. of material over a seam of anthracite coal was 81 per ton of material stripped, and 80.516 per ton of coal obtained. The average depth of the stripping was 75 ft. and about two-thirds of the material removed was rock. The cost of stripping a bank 15 to 18 ft. high in Western Pennsylvania was 80.30 per cu. yd. of stripping. By milling system, the deposit is stripped, shafts are sunk outside of the boundaries, and drifts are extended through the ore some distance from the surface. From these drifts, raises are put up to serve as chutes, after w r hich the material is simply blasted loose and worked into these raises, through which it passes to the underground passages, and is trammed to the shafts and hoisted to the surface. The advantages of this system over the steam-shovel methods are: It is not necessary to make any long cut through the overburden to bring the cars on the surface of the ore body. The mining force can be employed underground in extending drifts and driving new raises in bad or stormy weather. Very little handling of the material by manual labor is required, the men simply working the loosened ore into the chutes by means of bars or shovels, without having to lift any of it. Some of the soft-ore iron mines have used this system very advantageously. Cableways in Mining— Cableways are extensively used for stripping deposits, for transporting material after it has been quarried, and also for mining soft or loose deposits, such as clays, phosphates, and gravels, ine cost of removing the overburden varies greatly with the nature of the ground, and depends largely on the distance to which it is necessary to carry the waste material before dumping. Frequently, a cableway can be installed spanning both the place of mining and the dumping ground. In other cases, one end of the cableway is fixed and attached to a washing or gold-saving plant, while the other end revolves about this fixed point m a circle until all of the material within this circumference has been exca- vated; the entire plant is then moved to another location. The advantages of cableways over steam shovels or dredges are that the load may be delivered at a considerable distance from the point of excavation, while the entire apparatus rests on banks entirely clear of the excavation. Cablewavs have been constructed with single spans up to 1,650 ft., han- dling 25-ton loads, and delivering an average daily capacity (10 hours) of 617 vd. of rock Mr. Spencer Miller places the following limitations on the practical applications of cableways: Span (sdnglej^.OOO ft.; load, 2o tons, speed of travel, 1,800 ft. per minute; speed of hoist, 900 ft. per minute. The average practice, however, is about as follow’s: Span, 600 to 1.200 ft., loads, 3 to 7 tons, speed of travel, 500 to 1,000 ft. per minute; speed of hoist, loO to 300 ft. per minute. ... _ , f Placer or fragmental deposits may be worked by means of a stream of water from a pipe or nozzle directed against the bank (hydraulic mining), or the material may be excavated by hand or by mechanical means, such as dredges, steam shovels, etc. , , , . _ Hydraulic Placer Mines.— The material is broken down by water Sowing over the bank, as flume waterfalls, or along the ground so as to ground-sluice the material. The material is frequently just loosened by means of picks or shovels, the current being depended on to carry it away. This is commonly called ground sluicing. Another method of excavating the matenaL is to direct a stream of water against the bank from a pipe or nozzle. _ This is true hydraulicking. After the material has been loosened by the water, it is allowed to flow through sluices and over undercurrents or gold-saving tables so as to recover the valuable portions. CLOSED WORK. 279 Placer Mines Worked by Mechanical Means— Where water is scarce, the material may be excavated by steam shovels or other excavators, such as grab, or scooping, buckets, operated by cableways. The material is then washed by a limited supply of water that is frequently used over and over, or it may be passed over a dry washer or concentrator. Both the steam shovel and the cable excavator have proved very efficient means for working certain classes of deposits. Dredge Mining.— Where the gold-bearing material lies below the water level, or where water can be introduced so as to float a boat, a dredge may be employed. > For gold dredging, a dredge should fulfil the following conditions: (1) Speed and readiness in moving and taking up different positions; (2) an adaptability for cleaning up rock, and for digging to a maximum depth; (3) feasibility of working and of the banking or disposing of the tail- ings; (4) cheapness in working, as most of the dredging propositions are of low grade. , , ,, Three types of dredges have been used: the hydraulic suction dredge, the shovel dredge, and the continuous-bucket ladder dredge. The first of these is well adapted for digging very small gravel and sand, but is not suited for boulders or even large stones without a great loss of efficiency. The con- tinuous-bucket dredge has proved the most successful under ordinary cir- cumstances, as it is controlled by lines and not by spiles or spuds, and hence can be shifted more rapidly and made to conform to irregularities m the bed rock more readily than the dipper type. Also, the continuous-bucket dredge furnishes a constant supply of material to the apparatus used for recovering the gold. „ ^ A continuous-bucket dredge can operate to a depth of 60 ft. According to Mr. R. H. Postlethwaite’, of San Francisco, Cal., a decided advocate of continuous-bucket dredges, the cost of working a shovel dredge runs from 7 cents per cubic yard upwards; but he claims that the bucket dredge can be worked at a cost of from 3 to 5 cents per cubic yard, including a charge of $100 per week for depreciation. The cost of running a small gold dredger should not average over $200per week— that is allowing $125 for wages, $50 for fuel, and $25 for repairs, etc. If the dredger handles 10,000 cu. yd. per week, that would be at a cost of 2 cents per cubic yard. If the material averaged 6 cents per cubic yard, there should be an approximate profit of $400 per week on an investment of from $25,000 to $40,000. 18 cu. ft. of gravel in place will weigh 2,000 lb.; a cubic yard will weigh li short tons. 4 CLOSED WORK. Under this general heading it is customary to divide the methods of mining into coal-mining methods and metal-mining methods. This classifi- cation is not entirely logical, for identical methods are applied to nat bedded deposits of coal, iron ore, clay, salt, etc., and identical or very similar methods to highly inclined coal seams and mineral veins. A more logical classification is one based on the position, character, and thickness of the deposit, but the older classification has become so firmly established that it is not advisable to give it up entirely in a pocketbook. Bedded Deposits.— The typical and most extensive bedded mineral .deposits are of coal and iron ore, and of these the former is by far the more extensively mined. A description of the several methods of mining coal beds will therefore comprise not only all of the essential points in the mining of other bedded deposits, but will include a number of points not usually considered in mining such deposits. The chief of these is the presence of explosiwe gas in such quantities as to influence the choice of a method of mining, r rom the descriptions of the methods of coal mining here given it will therefore be a comparatively simple matter for the miner of clay, iron ore, etc. to adapt a method. COAL MINING. General Considerations.— The elementary causes affecting the extraction of coal are (1) weight of overlying strata or depth of the deposit; (2) strength and character of roof; (3) character of floor; (4) texture of bedded material; (5J inclination and thickness of bed; (6) presence of gas in the seam or in adjoining strata. 280 METHODS OF WORKING. Roof Pressure.— Of these causes, the roof pressure is the most impOTtant, and a number of the other causes are directly affected by it. The weight of the overlying cover will give a maximum roof pressure, but this may be so variously modified that the determination of the actual pressure is practically impossible, and estimates of this pressure must be based largely on practical experience; hence, rules for its calculation are of comparatively little value. One very essential point, however, must be borne in mind, 1 . e., that the direction of pressure is perpendicular to the bedding plane. Strength and Character of Roof.— The strength of roof refers to the power of being self-supporting over smaller or larger areas. A strong roof permits larger openings, but increases the load on the pillars, thereby necessitating larger pillars. A weak roof requires smaller openings, and permits smaller The character of floor influences largely the size of pillars. A soft bottom requires large pillars and narrow openings, especially when the roof is strong. Texture of Coal and Inclination and Thickness of Seam.— Soft, friable coal requires large pillars, while a hard, compact coal requires only small pillars. The inclination and thickness of the deposit increase the size of pillars required, and also influence the haulage, drainage, timbering, method of working, arrangement of breasts, etc. The presence of gas in the seam or in the enclosing strata affects the system of working, as ample air passages must be provided, and provision must fre- quently be made for ventilating separately the different sections of the mine. Where the gas pressure is strong, and outbursts are of frequent occurrence, narrow openings are necessitated that render the workings safe until the gas has escaped. ___ SYSTEMS OF WORKING COAL. There are two general systems of working coal seams: (1) room-and-pillar, and (2) longwall. There are, however, a great num- ber of modifications of each, and it is often diffi- cult to exactly classify a given method under either of these two systems. The room-and-pillar sys- te/n, also known as the pil- lar-and-chamber or bord- and-pillar. and which may include the pillar-and-stall , svstem, is the oldest of the systems, and the one very generally used in the mines of the United States. By this system, coal is first mined from a number of comparatively small places called rooms, chambers, stalls, bords . etc., which are driven either square from or at an angle to the haul- ageway. These openings may be wide or narrow, and may be either a road- way, incline, or chute, according to existing con- ditions. The pillars that are left between the open- ings in the original work- ings support the roof, and are usually subsequently removed. All forms of room-and-pillar workings become impracticable when the ^l ck ^y e f ^ pillars necessary to support the roof pressure much exceeds aouDie me width of the breast openings. LONG WALL METHOD. 281 The pillar-and-stall system is similar to the room-and-pillar system, but in the former the stalls are opened off from the entry their full width, while in the latter the rooms or chambers are turned narrow, and widened inside to their regular width. Fig. 1 shows a typical room-and-pillar method for working an approximately horizontal seam of coal of moderate thickness (4 to 10 ft.), and with a fairly good roof and bottom. Main headings A are usually driven perpendicular to the strike, unless this direction is changed by the cleat in the coal, as explained later. Cross-headings, or entries B, B, are turned off at regular intervals, and at an angle of 90 to these main headings, the distance between any two pairs of cross-entries being deter- mined, in flat seams, by twice the length to which a room can be driven, which in turn is determined by the character of the roof, floor, and seam. The rooms are turned to the right and left of each pair of butt headings, and driven until they meet, or one-half the distance between two pairs of entries. After the rooms are driven up, the pillars between the rooms are drawn, and later the room stumps along these entries, and the entry pillars themsel ves, are drawn, unless it should be necessary to keep some of these cross-entries open for purposes of ventilation. A large chain pillar is left to protect the main headings. , , When cross-entries have been extended a considerable distance, roads are often driven between them parallel to the main heading A. The object of these subroads is to reduce to a minimum the air-courses and roadways to be maintained; or such a subroad may be necessary on account of a squeeze crossing any pair of cross-entries. The extent of the territory worked out to the right and left of each main entry is a matter for local determination. The room openings are made suitable to prevailing conditions, and Fig. 1 shows several of the common methods. The width of the room and the form of the opening depend on the character of the roof and the extent to which it is necessary to leave a pillar to support the cross-heading, it being advan- tageous, of course, to open out the room to its full width at the earliest PO TongwanMethod of Mining.-The longwall system contemplates the extrac- tion of the entire seam or bed, and the original significance of the term “longwall” was a continuous line of breast. No portion of the seam is allowed to remain after leaving the vicinity of the shaft. The method depends on producing a uniform and gradual settlement of the root a tew yards behind the working face. Pack walls are built on each side of the roadways, and at regular intervals in the gob or waste area, and the root settles firmly on these packs, pressing them into the bottom, or compressing them until the roof subsidence is complete. The heignt of the main road- way is maintained by “brushing” the roof or lifting the bottom. Longwall may be advancing or retreating . In longwall advancing, mining begins at oi near the foot of the shaft and advances outwards forming a gradually widening and increasing length of face to the boundary. The passages are made through the excavated portions of the mine, and are maintained b> pack walls built either of the refuse secured in mining or sometimes from material brought in from the surface. In longwall ^fating or withdraw- ing, entries, gangways, or headings are first driven to the boundary or to other convenient distances inbye, and the pillars between these entries are then drawn back toward the shaft; this is also called working home. Fig. 2 shows a plan of combined longwall advancing and retreating, in the upper arrangement, or Scotch longwall, the face is semicircular and the roadsTe turned off at angles of 45° This plan issuitablefor seams up to 3 ft. thick with a weak top, and which pitch less than 20 , and situated at almost any depth. It is the one from which most of the longwall practice in the central coal basins of the United States is taken. In the lower ^por- tion, which shows one method of longwall retreating, narrow Parallel headings are driven in pairs to the boundary, being from 200 to 300 ft. apart. Such a combination of longwall advancing and retreating insures an unvarying supply of coal, for while one side continually leaves the shaft, the Longwall is specially adapted to flat seams or those having a regular and moderate pitch, and which are free from faults; to hard rather than to soft coal; and to the use of undercutting machines. It us also easy of venti- lation and economical in timber, explosives, and trank. In all longwall work, the w r eight of the roof is made to act upon the coal face, which is undercut, according to the ability of the miner and the con- ditions of the seam, from 2£ to 3 ft. deep. This weighing action of the roof 282 METHODS OF WORKING. performs the work of the powder and breaks the coal in a few hours or less, after the sprags have been removed. The time required to break the coal will be greater or less, according to conditions. The success of the entire system, as will be readily seen, depends on a uniformly regular advance of the line of the face or breast, and a uniform system of setting and drawing timber at the face; also, uniformity in the pack walls along the roads, and in the amount of gob packing. This system does not permit of long idle spells induced by strikes or other causes. The coal does not break well, either, when some of the men are out a portion of the time, and their places lie idle. The life of the whole system consists in maintaining what miners call a Fro. 2. traveling weight upon the coal face, which can only be accomplished satis- factorily by uniformity in every part of the work. Longwall advancing is better suited to thin seams than to thick ones, to flat rather than pitching, and to good roofs and hard floors. Longwall retreating is better adapted to thicker beds; to those liable to gob fires; to seams of hard coal having a considerable pitch; to pockety, or irregular seams; and to a soft and treacherous top. The air-course is also less broken along the face, and better haulage installations can be made. Its chief disadvantage is the large amount of dead work necessitated before returns are received. With this system there is no expense in keeping up the haulage road so far as creep or falling roof is concerned, as the roads are all in solid coal, nor is there any trouble from gob fires or water; and little STARTING LONGWALL. 283 detriment to the working face is caused by the mine having to stand idle for a time. If the seam is high enough for the mules . hors es> jo rock whatever will need to be taken down. The coal seam will be proved before ^The Ventilation ^n the retreating plan is as near perfect as it is possible to get it in practice. All the airways are tight, a thing impossible to get in the advancing plan; and it is a comparatively easy matter to shut off hre or to allow a portion of the working face to remain idle. o ,. e Longwall retreating is frequently used for working quite limited sections of a mine in which the seam of coal is 16 to 20 tt. thick, aQ d inclined not more than 10°. A series of 8 or 10 pairs of headings are turned off the butt entry and driven a distance, dependent on local conditions where the working face is formed by driving cross-cuts from one to th e° tb er* bice is carried back on the retreating plan, allowing the r ^ of ^9 or settle on the gob as the work approaches the butt entry. J 1 * way, any extra weight that would crush and rum the adjacent coal is avoided. This method is also used in lower seams in which the coal is soft, <3r ^eroof, or bottom, or both, are of such a nature as to give trouble m working the ^oom- and-pillar system. Sometimes, instead of driving pairs of headings at considerable 7 distances apart, a number of single headmgs are dri ven com- paratively close together, and connected by cross-cuts froni 1C (to 20 yd. apart When the limit of the section is reached, the working face is formed and carried back, as in the other plan. This latter method is more suita- ble for tender roof, or a coal in which the face and butt cleats are not Pr °S?artine Longwall. — There are two methods of starting longwall workings. In the first, the work of extraction begins at the shaft itself, the coal being taken out all around and its place filled with solid packs, leaving only space for the roadways. In the second method, a pillar of solid coal is port the shaft, cut only by the roadways. The longwall work is then started uniformly all around this pillar. Great care is n ee( i e( i iri build, the first pack walls around the shaft pillar, to see that they are and well rammed, in order to break the roof over the coal. The system will not work rightly, however, until the breast has been advanced some dis- tance from the pillar, so as to secure _ the benefit from the weighing action of the roof upon the coal face. The mining will be more difficult in the start, and in some exceptional cases it may even be necessary to place some light shots; which, however, should be avoided, if possible. . . The panel system divides a mine into districts or panels by driving entries and cross-entries so as taintersect one another at regular intervals of, usually, about 100 yd. Large pmars are left surrounding the workings within each panel, and any method of development may be used for each panel. This system presents the following advantages: (1) Better control of the ventila- tion, since the air in any panel may be temporarily increased or decreased, as required. An explosion occurring in one panel is less liable to afreet the other workings. (2) Coal may be extracted, pillars drawn, and the panels closed and sealed off independently of each other. (8) Greater security is afforded against creep and squeeze. (4) Coal that disintegrates on standing can be quickly worked out. , _ x Bearing In, or Undercutting.— In any method of mining where the coal is undermined, advantage should be taken of the roof pressure to assist m both breaking down the coal and also in bearing in. The fact is often overlooked that the roof pressure upon the face coal makes it brittle and more susceptible to the pick, and the good miner starts a shallow mining in the under clay, or lower coal, and carries it the entire width of the face. Bv the time he returns to the side of the breast at which he started, the roof pressure has made the coal more tender and susceptible to the pick, buch a gradual system of mining throws the pressure on the coal face gradually, and the coal breaks in larger pieces. The depth of the undercut depends on the thickness of the seam and the other conditions. Undercutting by mining machines is rapidly replacing hand work wherever these machines Ca ^Bunffing^.’Pack Walls, and Stowing.— Pack walls should be built large enough at first and kept well up to the face, to prevent the weight coming upon the timber and also to permit the roof to settle rapidly when the timber is taken out of the face. Often the roof will not stand this without breaking, and possibly closing in the entire face. The face should therefore be kept in shape, and just as soon as there is room for a prop or 284 METHODS OF WORKING. chock, it should be put in immediately, and the pack walls likewise should be extended after each cut or web is loaded out. As a general thing, the pack walls in the gob are not so wide as the road- side ones, particularly when the seam produces enough waste material to stow the “marches,” “ cundies,” or “gobs,” between these pack walls. Usually about 50/c of the cubical contents of the solid seam taken out will stow the spaces between the pack walls in thick pitching seams, where the entire gob must be completely filled or nearly so. No waste material, except such as will hasten spontaneous combustion, should be taken out of the mine to the surface. Timbering a Longwall Face.— The method of timbering the working face depends on the nature of the roof, floor, coal, etc. The action of the roof on the coal face is regulated almost entirely by timber; consequently, when the coal is of such a nature as to require little weight to make it mine easily, the roof must be timbered with rows of chocks and, if necessary, a few props. Control of Roof Pressure.— The working face of a longwall working should advance up grade, but this face cannot always be kept parallel with the strike. When the angle at the line of face, made with the line of strike, is less than 90°, the greater pressure of the covering rocks is thrown on the gob, and, when this angle is more than 90°, the greater pressure comes on the coal. The angle made by the working face with the line of pitch varies inversely as the vertical angle of pitch, or for a high pitch this angle is small and for a low pitch it is large. Where longwall is worked in adjacent sections, care must be taken to prevent the advancing of one section throw- ing a crushing weight on any of the others, and thus producing a crush or an uncontrollable cave. Where the rocks are pitching* and a greater portion of the cracks that cut them run in lines parallel to the strike, neither stone nor timber can efficiently support the roof, which frequently breaks off close to the working face. The ends of all stone packs nearest the face of the coal should be in line, and the ends of these pack walls should form a line parallel to the face of the coal. Timbers set at equal distances and in line along a longwall face are much more efficient in supporting the roof than irregularly set tim- bers. Fig. 3 shows the proper way of locating the pack walls and the face timber. Number of Entries.— The entries in a mine may be driven single , double , triple, etc. The single-entry system is only advisable under certain conditions and for short distances, since the ventilation must be maintained along the face of the rooms, and there is but one haUlage- way, which may easily be closed by a fall or creep. Rooms are turned off one or both sides of the entry. The double-entry system is most commonly used. Two parallel entries are driven, separated by an entry pillar whose thickness varies with the depth of the seam, and connected at intervals of about 20 yd. by cross-cuts or breakthroughs to maintain ventilation. The triple-entry system is used particularly in very gaseous seams requir- ing separate return airways; or, at times, in mines where the large output requires ample haulage roads. It is usually applied to the main entries only, but sometimes, also, to the cross-entries. In gaseous mines, the middle entry is usually made the haulage road and intake airway, and the outside entries the return air-courses for either side of the mine, respectively. A still larger number of entries even has been suggested for deep .'workings where it is difficult to keep open broad passages, but these have not been generally adopted or tried experimentally to any great extent. Direction of the Face. — The typical room-andqflllar plan, Fig. 1, shows the main headings and the rooms driven parallel to the direction of the dip, and the cross-headings parallel to the strike, but in most coal seams there are vertical cleavages, called cleats, which cross the coal in two directions about at right angles to each other. Face cleats, as they are called, are the more pronounced, while the end or butt cleats are the shorter, less pronounced joints. The direction of the face with respect to the cleats is of prime importance as greatly facilitating or retarding the mining of the coal. Fig. 4 shows the different positions that the face may occupy with respect to the direction of the cleats. The angle of the breast depends on the hard- ness of the coal and freedom of the cleats, and each method has its peculiar Fig. 3. PILLARS. 285 adaptation to the varying conditions of a coal seam. When the face cleats are working free and the coal is very soft , it may be necessary to drive “ end on.” The end-on method is best adapted to a very heavy roof pressure, while for a light roof pressure the short-horn method assists in breaking the coal. If the “ face ” cleats are free and the coal breaks readily along them, and it is reasonably hard , the long-horn method is adopted, for when the coal is undercut it needs more support than it gets from the cleats, and its weight must be thrown somewhat upon the end cleats. “ Face on” is adopted when the face cleats are not as free or numerous as the butt cleats. Unless the coal at the face re- ceives sufficient support, the undercutting or bearing in can- not be thoroughly done, or else the amount of spragging and the risk to the miner are in- creased. When the end cleats are less pronounced and nu- merous, and the roof pressure reat, the coal will probably reak better by carrying wide breasts upon the ends of the coal, and it is then an advan- tage to drive double rooms with large pillars between them. In pitching seams, the pillar should have very long sides perpendicular to the strike, if the principal cleats in the coal are parallel to the strike, or nearly so. , The short-horn method is adapted to heavy roof pressure and wide room pillars, as the face cleats are here quite pronounced, and the pillars between the rooms thereby weakened to a large extent; hence, wide pillars are more often employed when working on the ends of the coal. When the face cleats are less pronounced, and the end cleats are working freely, a good breast of coal is carried on the face, and, unless other conditions require it, a great width of room pillars is not needed. If this can be done consistently, and good lump coal secured at the same time, the room should cross the pitch as little as possible, as a side pressure upon the pillars having very long sides running diagonally across the pitch is destructive. PILLARS. Size of Pillars.— It is impossible to give exact rules or formulas for deter- mining the proper size of pillars. Each case in practice requires special consideration, and in laying out the pillars in a virgin field it is well to find out what the current practice is in similar fields. In general, the thicker the seam and the greater its depth from the surface, the greater should be the thickness of the pillar. Some coal deteriorates rapidly when subject to weight and to the disintegrating effect of the atmosphere, and pillars of such coal must be larger than when composed of a hard, compact coal. Permanent pillars, or those that are to remain for a considerable length of time, must be larger than those that are to be promptly removed. Pillars about the bottom of a shaft, or along main haulage roads, should be left large enough to provide for increasing developments, for when landings are enlarged or when haulage systems are introduced, the original pillars fre- quently have to be reduced in size by taking a skip off of them or by taking out chambers for engines and pumps. . Shaft Pillars.— Various formulas have been given to determine the size of shaft pillars, and the results given by these several formulas are very diverse. Merivale. — S = X 22, where S equals the length of the side of the pillar in yards, and D equals depth of shaft in fathoms. Andre— Up to 150 yd. depth, have the pillar 35 yd. square, and for greater depths increase 5 yd. on each side for every 25 yd. of increased depth. Dron. — Draw lines enclosing all surface buildings that it is necessary to erect about the head of the shaft, and make the shaft pillar so that solid coal will be left outside these lines all around for a distance equal to one- third the depth of the shaft. Wardle.— Shaft pillars should not be less than 40 yd. square down to a depth of 60 fathoms, and should increase 10 yd. on a side for every 20 fathoms increase in depth. Fig. 4. 286 METHODS OF WORKING. Hughes. — Leave 1 yd. in width of pillar for every yard in depth of shaft. Pa mely.— Allow a pillar 40 yd. square for any depth up to 100 yd.; for greater depths, increase the pillar 5 yd. for every 20 yd. in depth. Calculating the size of pillar from each of these authorities, we find the Authority. For Shaft 300 Ft. Deep. For Shaft 600 Ft. Deep. Merivale 4ndre 22 yd. square. 35 yd. square. 31 yd. square. 45 yd. square. Wardle Pamely Dron Hughes 40 yd. square. 40 yd. square. 33i yd. square.* 100 yd. diameter. 60 yd. square. 65 yd. square. 66f yd. square.* 200 yd. diameter. •Outside of buildings. None of these formulas takes account of the thickness of the seam, and the following formula, which takes account of this veiy important element, was suggested by Mr. R. J. Foster, in “ Mine s and Minerals . Radius of pillar = Z\/ D X U in which D = depth of shaft; t = thickness of seam. Pitching seams require smaller pillars on the low side than on the rising Sid RooV^PM Tars.— The relative width of pillar and breast is dependent on the weight of cover, as compared with the character of the roof and floor, and the crushing strength of the coal. These relative widths are deter- mined largelv by practice. Speaking generally, the narrower the rooms or chambers. ‘the higher the cost in yardage, the greater the production of slack and nut coal, the greater the consumption of powder, track iron, ties, etc., and the greater the cost of dead work. , For bituminous coal of medium hardness and good roof and floor, a rale often used is to make the thickness of room pillars equal to 1* of the depth of cover for each foot of thickness of the seam, according to the expression W p = ^ X A in which W p = pillar width; t = thickness of seam- D = depth of cover, and then make the width of breast or opening equal’ to the depth of cover divided by the width of pillar thus tound, according to the expression W 0 = where W 0 = width of room. Frail coal and coal that disintegrates readily when exposed to the air, and a soft bottom, may increase the width of pillar required as much as o0* of the amount found above; also, a hard roof may increase the same as much as 254; while on the other hand, a frail roof or a hard coal or fl(x>r may reduce the width of pillar required 25*. The hardness of the roof affects both the width of pillar and width of opemng alike, which is not the case with any of the other factors. Dunn’s Tables of Size of Room Pillars for Various Depths. The following table is for first working, with the design of afterwards taking out the pillars, the width of the principal workings being 5 yd., and Depth. Feet. Size of Pillars. Yards. Proportion in Pillars. Depth. Feet. Size of Pillars. Yards. Proportion in Pillars. 120 20 X 5 .41 1,080 26 X 14 .69 240 20 X 6 .50 1,200 26 X 16 .71 360 22 X 7 .52 1,320 28 X 18 .73 480 22 X 8 .57 1,440 28 X 20 .75 600 22 X 9 .59 1,560 30 X 21 .77 720 22 X 12 .61 1,680 30 X 22i .78 840 26 X 15 .63 1,800 30 X 24 .79 960 28 X 16 .66 ROOM PILLARS. 287 Extremely large pillars must often be left as a precautionary measure to protect permanent haulageways and surface buildings, or to avoid any pos- sibility of a break in the roof that would cause an inflow of water. Table Showing Distance From Center to Center of Breasts or Chambers Measured on the Entry or Gangway, for Different Angles. A I to I B © © 0 ^© Distance Measured on the Entry in Feet, When Width of Breast + Width of Chamber Is: 03 r ' h q; f-i . 20 25 30 35 40 45 50 65 60 65 70 75 90 20.0 25.0 30.0 35.0 40.0 45.0 50.0 ■ 55.0 60.0 65.0 70.0 75.0 85 20.0 25.1 30.1 35.1 40.2 45.2 50.1 55.2 60.2 65.3 70.3 75.3 80 20.3 25.4 30.5 35.5 40.6 45.7 50.6 55.8 60.9 66.0 71.1 76.2 75 20.7 25.9 31.1 36.2 41.4 46.6 51.2 56.9 62.1 67.3 72.5 77.7 70 21.2 26.6 31.9 37.2 42.6 47.9 53.1 58.5 63.9 69.2 74.5 79.8 65 22.0 27.6 33.1 38.6 44.1 49.6 55.1 60.7 66.2 7L7 77.2 82.8 60 23.0 28.9 34.6 40.4 46.2 52.0 57.6 63.5 69.3 75.1 80.8 86.6 55 24.4 30.5 36.6 42.7 48.8 54.9 60.9 67.1 73.3 79.4 85.5 91.6 50 25.8 32.6 39.2 45.7 52.2 58.7 65.1 71.8 78.3 84.9 91.4 97.9 45 28.2 35.4 42.4 49.5 56.6 63.6 ^0.6 77.8 84.9 91.9 99.0 106.1 40 31.1 38.9 46.7 54.5 62.2 70.0 77.6 85.6 93.4 101.2 109.0 116.7 35 34.9 43.6 52.3 61.0 69.7 78.5 87.0 95.9 104.6 113.4 122.1 130.8 30 40.0 50.0 60.0 70.0 80.0 90.0 100.0 110.0 120.0 130.0 140.0 150.0 25 47.3 59.2 71.0 82.8 94.6 106.5 118.1 127.2 142.0 153.8 165.7 177.5 20 58.5 73.1 87.7 102.4 117.0 131.6 145.9 160.8 175.5 190.1 204.7 219.3 15 77.4 96.6 115.9 135.3 154.5 ]73.9 192.8 212.5 231.9 251.2 270.5 289.8 10 115.2 144.0 172.8 201.6 230.4 259.2 287.3 316.7 345.6 374.4 403.1 432.0 5 229.5 286.9 344.2 401.6 459.0 516.3 572.5 631.1 688.5 745.8 803.2 860.5 In the following table, the weight thrown upon pillars at different depths by the removal of different proportions of coal is given: Weight on Pillars in Pounds per Square Inch. Percentage of Coal Left in Pillars. Depth Sean Feel 90/. 80/ 70/ 60/ 50/ 40/ 30/ 20/ 10/ 100 Ill 125 142 166 200 250 333 500 1,000 500 555 625 710 830 1,000 1,250 1,665 2,500 5,000 1,000 1,111 1,250 1,428 1,666 2,000 2,500 3,333 5,000 10,000 1,500 2,000 3.000 4.000 5.000 10,000 1,666 2,222 3,333 4,444 5,555 11,110 1,875 2,500 3,750 5,000 6,250 12,500 2,138 2,956 4,384 5,912 7,340 2,496 3,333 4,999 6,666 3.000 4.000 6.000 8,000 3,750 5,000 7,500 4,998 6,666 7,500 15,000 Chain and barrier pillars vary in size even more than shaft pillars, and their widths are almost entirely determined by local considerations. In some States, the minimum width of barrier pillars is regulated by law. Barrier Pillars. — For finding the width of barrier pillars in anthracite seams, the following formula, adopted conjointly by the chief mining engi- neers of the Lehigh & Wilkes-Barre Coal Co., Susquehanna Coal Co., D., L. & W. R. R. Co., Delaware & Hudson Canal Co., and the State mine inspectors of Eastern Pennsylvania, is recommended: Formula for width of barrier pillars: (Thickness of workings X 1 / of depth below drainage level) + (thickness of workings X 5). Thus, for a seam 6 ft. thick, 400 ft. below drainage level, the barrier pillar should be (6 X 4) + (6 X 5) — 54 ft. Depth Below Water Level — All Dimensions in Feet. Formula. — (Thickness of workings X 1* of depth below drainage level) + (thickness of workings X 5) = width of barrier pillar. 288 METHODS OF WORKING. 00$ *1 I 88388888883888888888888 09*‘l ] OXOCNNC^iOiO^'l'COCCNNHHOOC'.C'.QCOO rH rH rr rH rH CO CO CO CO CO 00*‘l t^tOiCTrMMr-iOC'.XC'CiO^COMiHOC'.Xt^tOiO ^ CC US I> CT- OOW^XOC^^OCOi-CCiCfr- ^ T-H 1-1 Lt -M S -iiiONMO^M ^«* ro a3SSSS38c3lS8S8S88g:3 001*1 | 8S882838i5g$SS8£8S883$S3 090*1 | t^MXWOJ'7'OOHtOCi-!OO^C5'^QCOO ^SKxOrtMTfCNXOr-X^cCt^COHM^O ^ 1 — r rH T-i rH i-H d OCOOC5^;ot^coocsco C^^MM'^iOiO'-Ot't'XClC.OrTiINMM^LCOO rH rH rH rH rH rH rn rH rH rH 001 H^Mcc^^ioc^t-t>xocr. 00 ii!£232;2S2^i2 rH rH rH rH rH rH rn rn rn 09 NNXMO'fOiOr-'ONt'MCC^aOgvDHN^OO i-inClCOCQ'^iQiQO^r < t^ c OwOiClOHHC^?|COCO 0 lOOiOOiCOOOiOOiOOlOOiCOOOOO^OsO H^(NMW^'1'iOiOO(5t't'XX05CSOOHH?lN r d a> : : : : : : : j : : : | : : : : i j 1 j j : i • , • • • • : ! * . * • • • • • i ? • ; ! • s o 2 E-i co «t to as eo oa cm eo 03 to r- oo a> o — cmco«* m CM CM CM CM CM CM Each adjoining owner is to leave one-half of the pillar thickness required. PILLAR DR A WING. 289 Compressive Strength of Anthracite.— Attention has recently been called by Mr. William Griffith, of Scranton, Pa., to the advisability of testing the strength of the different coals and of using this data as a basis for the proper proportioning of the pillars and for determining the probability of a squeeze. Jn some crude experiments, which Mr. Griffith carried on, he found that different coals from even the same locality varied greatly in their strengths. If attention were given to this matter, probably the sizes of pillars could be calculated on a much more certain basis than is possible at present, and the liability to squeeze lessened. The table on page 290 gives the results of some preliminary and crude tests made by Mr. Griffith, which supply the only data available as to the crushing strength of anthracite coal. Drawing pillars is about the most dangerous work the miner has to perform, but the met of its being so is no doubt the reason why, comparatively speaking, so few serious accidents happen in it. It is not so much that the best, most skilled workmen are chosen to perform pillar drawing, as that the men, being alive to the dangers, are more on the alert and careful to protect themselves. Sometimes, if not very often, in chamber or room-and-pillar working it is the custom to work out the rooms or chambers and leave pillars all the way from the shaft to the boundary line over large areas; in other words, the portion of the roof left standing on pillars is very extensive. Mines so worked have sometimes been spoken of as mines on stilts. To this mode of proceeding there are several serious objections. By leaving the pillars until the boundary has been reached, a large number of airways and roadways have to be kept open and in repair, and this number is constantly increasing until the limits of the workings have been reached. This circumstance renders the ventilation more difficult, and thereby increases risks of accident. Moreover, the length of time during which the old rooms and pillars are left open and standing increases the danger of squeeze and creep Fig. 5. Fig. 6. setting in, by which a large area may in a short time be overrun. Also, by this method, the pillars first formed are last removed, and hence it happens that a large number of them crack and give way under the combined action of atmospheric agencies and great pressure. Even if they resist these actions well, the quality of the coal greatly deteriorates by the long exposure. For the above reasons, it is the best practice to carry on the two workings (working the rooms and drawing the ribs and pillars) simultaneously. By so doing, the length, mean duration of the roadways, etc. are reduced, and the pillar coal obtained in much better condition; and, in order to concen- trate the workings as much as possible, the two operations should go on as closely together as practicable. With fairly thick and very soft coals, the rapid working up of the rooms and equally quick drawing of the ribs, as soon as the rooms are driven their full distance, is essential to economical working; for delay in extracting ribs and pillars in such circumstances results in their getting crushed and the coal lost or largely ground to slack, waste of props and material, disordered ventilation, and shortened life of the mine. Methods of drawing pillars vary according to the inclinations of the seams, the nature of the roof and floor, and the character of the coal. Figs. 5 and 6 show the common methods. In Fig. 5, A, B, and C, the drawing begins by cross-cutting the fast ends of the pillars to obtain a retreating face. A shows a method for soft coal and narrowing pillars, B for wide Tests of Compressive Strength of Sawed Pieces of anthracite Coal. 290 METHODS OF WORKING. Remarks. Checker coal from Exeter. Checker coal M. W. coal pile. Checker coal bottom of Clear Spring colliery. Clear Spring Pittston vein glassy coal. Clear Spring Marcey checker coal. Clear Spring Marcey checker coal. Clear Spring Marcey checker coal. Clear Spring Marcey. Very good test. Checker coal. Clear Spring Marcey. Knot in block. Not fair test. Clear Spring reddish glassy coal. Clear Spring reddish. Not fair average test. Crushing Weight. Tons. Deduced. Per Cu. In. CO © I— J O') © r-J I-J H'^'^COi-HC- <^c4r-5©fHr-3iHCOCli— i' Breaking Weight. Tons. Deduced. Per Cu. In. ONClONOJN . Oioooco^o — 'GO ao © © O'-, c^. C^. lO © i“ 1 OO lO '-H ^ ^ ' H H H rH Average Weight Sustained. Crush- ing. Tons. t'-»o>ia©ioioi>-©G 003 CO(MCOCOl>*CQ'MI>iOCO w Break- ing. Tons. 28 (?) 17 (?) 30 (?) 28 (?) 30 20 22 38 32 22 30 Dimensions of Test Piece. Height. r-tC4CCOCOlO> *1S9X jo jaqxnnK i-HMCO''*iiO©t>CC©©^| 1 pillars, the end being taken in two lifts, while C is for harder coal and shows it taken in three lifts. D and E show the pillars cut into stocks to be drawn by side or end lifts, according to the character of the coal, the inclination of the seam, thickness of the cover, and the strength or weak- ness of the roof and floor. Fig. 6 shows some of the methods used in robbing the pillars in steep pitch- ing, thick beds of anthra- cite. To get the coal out of the pillar at the left of A, a skip is taken off the side, as shown. Suc- cessive skips are thus taken off until the whole is removed, the miner keeping the manway open to the heading be- low as a means of retreat. The pillar between A and B is very similarly worked. To remove that between B and C, a nar- row chute or heading is driven up the middle, and cross-cuts put to the right and left a few yards from the upper end. Shots are placed in the four blocks of coal thus formed, as shown, and they are fired simultane- ously by battery. This operation is repeated in each descending portion unless the pillar begins to run. A pillar from which the coal has started to run is shown to the right of C. To secure the highest percentage of pillar coal, a method should be adopted that will pre- vent squeezing or crush- ing, if possible. All the pillars in a panel may be taken out at the same time by end lifts in such a way as to keep the face of all the lifts in line and perpendicular to the sides of the pillars, or the pillars are drawn in lifts of three or more pillars each, the centers of the face of the lifts lying in a straight line that makes an angle of about 40° with the sides R 0 OM-AND-PILLA R METHODS. 291 of the pillars. (See also “ Flushing of Culm,” which is described fully on page 314.) Gob fires are due to the spontaneous ignition of coal, and are most likely to occur in pack walls and gobs where there is an insufficiency of air. Ample ventilation is the best preventive. Spontaneous Combustion.— According to Prof. Able, Dr. Percy, and Prof. Lewes, the causes of the spontaneous ignition of coal are: First , and chiefly, the condensation and absorption of oxygen from the air by the coal, which of itself causes heating, and this promotes the chemical combination of the volatile hydrocarbons in the coal and some of the carbon itself with the condensed oxygen. This process may be described as self-stimulating, so that, with conditions favorable, sufficient heat may be generated to cause the ignition of portions of the coal. The favorable conditions are: A mod- erately high external temperature; a broken condition of the coal, affording the fresh surfaces for absorbing oxygen; a supply of air sufficient for the P urpose, but not in the* nature of a strong current adequate to remove the eat; a considerable percentage of volatile combustible matter or an extremely divided condition. Second , moisture acting on sulphur in the form of iron pyrites. The heating effect of this second cause is very small, and it acts rather by breaking the coal and presenting fresh surfaces for the absorption of oxygen. Coal Storage.— Prof. Lewes gives the following recommendations for the storage of coal: “ The coal store should be well roofed in, and have an iron floor bedded in cement; all supports passing through and in contact with the coal should be of iron or brick; if hollow iron supports are used, they should be cast solid with cement. The coal must never be loaded or stored during wet weather, and the depth of coal in the store should not exceed 8 ft., and should only be 6 ft. where possible. Under no condition must a steam or exhaust pipe or flue be allowed in or near any wall of the store, nor must the store be within 20 ft. of any boiler, furnace, or bench of retorts. No coal should be stored or shipped to distant ports until at least a month has elapsed since it was brought to the surface. Every care should be taken during loading or storing to prevent breaking or crushing of the coal, and on no account must a large accumulation of small coal be allowed. These precautions, if properly carried out, would amply suffice to entirely do away with spontaneous ignition in stored coal on land.” When the coal pile has ignited, the best way to extinguish the fire is to remove the coal, spread it out, and then use water on the burned part. The incandescent portion is invariably in the interior, and when the fire has gained any headway usually forms a crust that effectually prevents the water from acting efficiently. MODIFICATIONS OF ROOM-AN D-PI LLAR METHODS. Some modifications of the room-and-pillar plan shown in Fig. 1 can usually be applied to seams whose dip does not exceed 3°. When the pitch is greater, rooms are often turned off toward the rise only, and the cross- entries driven correspondingly closer together. When the pitch is from 5° to 10°, the cars may still be taken to the face if the rooms are driven across the pitch, thus making an oblique angle with an entry or gangway, the rooms being known as room breasts. Buggy Breasts.— For inclinations between 10° and 18°, that is, after mule haulage becomes impossible and until the coal will slide in chutes, buggies are often used. Fig. 8 shows a buggy breast in plan and section. Coal is loaded into a small car or buggy c, which runs to the lower end of the breast and there delivers the coal upon a platform l , from which it is loaded into the mine car. The refuse from the seam is used in building up the track, and if there is not sufficient refuse for this, a timber trestle is used. Another form of buggy breast is shown in Fig. 7. Here the coal is dumped directly into the mine car from the buggy. If the breast pitches less than 6°, the buggy can be pushed to the face by hand, but in rooms of a greater pitch, a windlass is permanently fastened to timbers at the bottom of the breast, while the pulleys at the face are temporarily attached to the props by chains, so that they can be advanced as the face advances. The rope used is from £ in. to f in. in diameter, and any form of ordinary horizontal windlass can be used. With the windlass properly geared, one man can easily haul a buggy to the face of a breast in a few minutes time. The buggy runs upon 20-lb. T rails spiked with 2£" X 1" spikes upon 2" X 4" 292 METHODS OF WORKING . hemlock studding sawed into lengths of 14 ft. This system has been thoroughly tested by the Delaware & Hudson Canal Co., Scranton, Pa., and has proved a very successful and economical one. _ _ Chute Breasts.— Seams pitching more than 15° are usually worked by chutes, or self-acting inclines. When the pitch is between 15° and 30°, sheet iron is laid to furnish a good sliding surface for the coal. On inclinations of less than 18° to 20°, it is usually necessary to push the coal down the chute Sheet iron is not required on pitches above 30°. It must be remem- bered that these pitches are only fair averages, as much depends on the character of the coal. Anthracite slides more easily than bituminous. _ To secure the best returns from a coal seam, the slope or shaft should be driven to the basin, and the lowest gangways or levels first driven to the property limits, and the coal then worked retreating toward the slope or shaft. Practice is, however, usually contrary to this, and the upper levels or gang- wavs are turned off first, and working places opened out as rapidly as the gangway is driven. Fig. 9 shows a method of grouping rooms that may be Fig. 7. used where the pitch is from 8° to 20°, the straight heading being driven on the strike and the other headings at such angles as will give a good grade for haulage purposes. The pillar-and-stall system is a modification of the room-and-pillar, to which it is similar in ali respects excepting in the relative size of the pillars and breasts. The stalls are usually opened narrow and widened inside, according to conditions of roof, floor, coal, depth, etc., being from 4 to 6 yd. in the single-stall method, with the pillars about the same width. Fig. 10, A and B , shows single and double stalls. This system is adapted to weak roof and floor, or strong roof and soft bottom, to a fragile coal, or wherever ample support is required, and is particularly useful in deep seams with CONNELLS VILLE METHOD . 293 great roof pressure. Double stalls are often driven from 12 to 15 yd. wide, with an intervening pillar of sometimes 30 yd. A „ The following are a few of the applications of the pillar-and-stall method of working as they are carried out in some of the leading coal fields of America i Connellsville Region (if. L. Auchmuty) .—Fig. 11 shows the common method used in the Connellsville, Pa., region. The average dip is about 50. The face and butt headings are driven, respectively, at right angles to each other on the face and the butt of the coal. The face headings leave the main butts about 1,000 ft. apart, while from these face headings, and 400 ft. apart, secondary butts are driven, and again from these butts on the face of the coal the rooms or wide work- ings are excavated to a length of 300 ft., this having proved the most convenient length for economical working. Koom pillars have a thickness of 30 to 40 ft., while the rooms are 12 ft. in width and are spaced 42 to 52 ft. between centers, de- pending on depth o strata over the coal. The headings are 8 ft. wide, and in all main butts and faces the dis- tance between centers Fig. 9. of parallel headings is 60 ft., leaving a solid rib of 52 ft. A solid rib of 60 ft. is also left on the side of each main heading. The average thickness of cover at the Leith mine, which 294 METHODS OF WORKING. is here described and which may be considered as a type of the region, is 250 ft., the overlying measures being alternated layers of soft shale ’ & and coal for 4 ft. The bottom is an 18" layer of hard fireclay and slate. These floor and roof materials are soft, and are easily disintegrated by air and water. At some mines, cover will Teach as much as 700 ft., and the dip of 5 £ (as at Leith) is much heavier at some points on eastern out- crop, and will run as high as 12<, flattening off as the synclinal line of the basin is reached, until it is almost level. In some localities, the material below coal is hard limestone, requiring blasting to remove it, and at other places the roof slates are much more solid than at Leith, and not read- ily disintegrated. The method of drawing ribs is one of the beauties of the system, since it is i harder to do succe ssfull y in a soft coal like the Connellsville coal than in hard coal. The Fig. 10. Fig. 1L CLEARFIELD METHOD. 295 coal nself is firm. When necessary to protect the top or bottom, 4 to 6 in. of coal are left covering the soft material. The method as given above is often applied to a whole series of butts (4 or 5) at once instead of to butt by butt, as shown in Fig. 11. In this case, work is started at the upper end of the uppermost butt and progresses, as shown in Fig. 11; but, after cutting across the butt heading from which the rooms were driven, the butt heading itself and the upper rooms from the second butt, or that just before, are likewise drawn back by continuous slices being removed from the rooms of the upper butt, and on across the next lower butt, etc., all on an angle to the butts, and so continued as the operations progress, until another butt is reached, etc., thus gradually making a longer and longer line of fracture, which is only limited by the number of butts it is desired to include at one time in the section thus mined. This works very nicely and makes long even lines of fracture, the steps of the face of the workings (in the rib drawing) being about 30 ft. ahead of one another. Pittsburg Region {H. L. Auchmuty ) .—The coal is worked in much the same way as in the Connellsville region, except that a different system of drawing ribs is used. The coal is worked on the room-and-pillar system, with double entries, with cut-throughs between for air, and on face and butt, entries are about 9 ft. wide, and the rooms 21 ft. wide and about 250 ft. long; narrow (or neck) part of room, 21 ft. long by 9 ft. wide; room pillars, 15 to 20 ft. wide, depending on depth of strata over the coal, which is from a few feet to several hundred feet. The mining is done largely by machines of various types. Coal is hard, of course, and, in many places, the roof immediately over the coal is also quite hard. There are about 4 ft. of alternate layers of hard slate and coal above the coal seam. Rooms are mined from lower end of butt as fast as butt is driven, the ribs being drawn as mining progresses. As the coal is harder than in the Connellsville region, thickness of coal pillar between parallel entries is somewhat less. Clearfield Region ( G . F. Duck ).— The butt and face are not strongly marked in the B or Miller seam, the one chiefly worked in this region. Where possible, these cleavages are followed in laying out the workings, but the rule is to drive to the greatest rise or dip and run headings at right angles to the right and left, regardless of anything else. The main dip or rise heading is usually driven straight, and is raised out of swamps or cut down through rolls— very common here— unless they are too pronounced, when the head- ing is curved around them. The same is true of room headings, except that they are more usually crooked, not being graded except over very minor disturbances. As the B seam rarely runs over 4 ft. in thickness, and is worked as low as 2 ft. 8 in. in the haulage headings, the roof is taken down to give 5 ft. to 5 ft. 2 in. above the rail, or 5 ft. 8 in. to 5 ft. 10 in. in the clear. Where the resulting rock is taken outside, the headings are driven 10 ft. wide with 24 ft. of pillar, roof taken down in haulage heading but not in air-course. Where the rock is gobbed underground, the haulage heading is 18 to 24 ft. wide, air-course 10 ft., pillar 24 ft., and roof taken down in haulage heading only. The thinner the coal, the wider the heading. It is more economical to haul the rock to daylight. The bottom generally consists of 3 ft. to 5 ft. of hard fireclay, frequently carrying sulphur balls. In numerous places, the sand rock is immediately over the coal, but in most cases there is from 3 to 5 ft. of slate before the sand rock is reached. Room headings are driven 280 ft. apart, haul rock to daylight, heading 10 ft. wide with 24 ft. pillar to 10 ft. air-course, in which roof is left up. A 15 ft. to 25 ft. chain pillar is left between air-course and faces of rooms from the lower heading, every fourth to eighth of which is driven through to the air-course to shorten the travel of the air. The rooms are therefore 180 to 200 ft. long, and the men push the cars to the face, an important economical item in this thin coal. Rooms are 21 ft. wide with a 15 ft. pillar, and a 15 ft. chain pillar is left between the first room on any room heading and the main heading, and roof is not taken down in rooms. Main-heading track is usually 30-lb. iron, room heading, 12 lb., and 2" X *" strap iron set on edge is used in the rooms in low coal. Mine cars hold from 600 to 800 lb. in low seams, and 1,500 to 2,000 lb. in the so-called thick seams, i. e., 3 ft. 8 in. to 4 ft. thick. Reynoldsville Region.— The measures are very regular, and the method employed the typical one shown in Fig. 1. The average thickness of the principal seam is 6£ ft. and the pitch is 3° to 4°. The coal is hard and firm, \ 296 METHODS OF WORKING. and contains no gas; the cover is light, and on top of the coal there are 3 or 4 ft of bony coal; the bottom is fireclay. Drift openings and the double- entry system are used. Both main and cross-entries are 10 it. wide, with a 94-ft pillar between. The cross-entries are 600 ft. apart, and a 24 ft, chain pillar is left along the main headings. The rooms are about 24 it. wide and open inbye, the necks being 9 ft. wide and 18 ft. long. The pillars are from 18 to 30 ft. thick. . West Virginia ( James W. Paul).— The general plan of working the Pitts- burg coal in the northern part of West Virginia is as follows. The coal measures vary from 7 to 8 ft. in thickness, and have a covering varying from 50 to 500 ft. The coal does not dip at any place over 5$. In most places the coal is practicallv level, or has just sufficient dip to afford drainage. The usual method of exploitation is to advance two parallel headings, 30 ft. apart on the face of the coal. At intervals of 500 to 600 ft., cross-headings are turned to right and left, and from these headings rooms are turned off. These cross-headings are driven in pairs about 20 or 30 ft, apart. Between the main headings and the first room is left a block of coal about 100 ft., and on the cross-headings there is often left a barrier pillar of 100 ft. after every tenth room. The headings are driven from 8 to 12 ft. wide, and the rooms are made 24 ft. wide and 250 to 300 ft. long. A pillar is left between the rooms about 15 to 20 ft. wide. These pillars are withdrawn as soon as the panel of rooms has been finished. The rooms are driven in from the entry about 10 ft. wide for a distance of 20 ft., and then the room is increased m width on one side. The track usually follows near the rib of the room. Cross-cuts on the main and cross-headings are made every 75 to 100 ft., and m rooms about every 100 ft. for ventilation. . . . ~ ^ The double-heading svstem of mining and ventilation is m vogue. Over- casts are largelv used, but a great many doors are used in some of the mines. Rooms' are worked in both directions. This is the general practice when the grades are slight. When the coal dips over 1#, the rooms are driven in one direction only. In this case, the rooms are made longer, as much as 350 ft. It is the custom then to Break about every third room into the cross-heading above (a practice ill advised). The floor of this bed of coal, being composed of shale and fireclay, often ALABAMA METHODS. 297 heaves, especially when it is made wet. Some trouble is at times experi- enced by having the floor heave by reason of the pillars being too small for the weight they support. . . The dimensions of rooms and pillars given are for a mine (with covering 300 to 500 ft. thick) having a fairly good and strong roof. Where roof, bottom, and thickness of cover change, these dimensions are altered to suit the requirements. The main-heading pillars may be reduced to 30 or 40 ft.; the rooms may he made 15 ft. wide with 12 ft. pillars, and no harrier pillars mav be left on the cross-headings. The foregoing plan is very much followed in other parts of the State; at least an attempt is made to do so, but local disturbances often require changes in the plan. This plan is followed on some parts of New River, and also in the Flat Top field. Alabama Methods (J. E. Strong).— Fig. 12 shows the common methods used in working the Alabama coals. The seams now working vary from 2 to 6 ft. thick, and they pitch from 2° to 40°. Where the seams are thin, the coal is hard, and pillars of about 20 to 30 ft. are used to support the roof. Fig. 13. The thick seams are soft and easily broken, and much larger pillars are left. The character of bottom and top varies; fireclay bottom and slate roof are usually found with the thick seams, and hard bottom and sandstone rqof with the thin, seams. The general plan of laying out the mine is to drive the slope straight with the pitch of the seam; this is usually on the butts of the coal. A single-track slope is 8 ft. wide, and a double-track slope 16 ft. Cross-headings are driven or turned from the slope water level every 300 ft.; air-courses are driven parallel on either side of the slope. Where an 8 ft. slope is driven, 30 ft. of pillar are left between the slope and airway, and for a 16 ft. slope, 30 ft. of pillar. The size of pillar, however, depends largely on the character of the roof and thickness and strength of coal. On the lower side of the headings, pillars from 20 to 60 ft. are left on the entry before turning the first room. The rooms are worked across the pitch on an angle of about 5° on the rail, Fig. 12, A, when the coal does not pitch greater than 20°; where the pitch is greater, chutes are worked and the rooms are driven straight up the pitch (Fig. 12, B). In a few cases, where the pitch is not greater than 15°, double rooms are worked with two roadways in each room (Fig. 12, C). A rope with two pulleys is used, and each track keeps the rib side of the room, the loaded car pulling up the empty on the opposite side of the room; distance between room centers, about 42 ft. Where single rooms are worked, the room is driven narrow (8 ft. wide) for 21 ft., when connections are made with the room outside of it; the room is then widened out to about 25 ft., sloping gradually until this width is at tained; pillars of from 10 to 20 ft. thick are left between the rooms, and cross-cuts fdr ventilation are made about every 50 ft.; every third or fourth room is driven through to the entry above; pillars are then drawn back to the entry stumps or pillars. The average cover over the coal now working is from 100 to 600 ft. Air-courses usually have an area of 30 ft., and sufficient coal is taken out to give this area, the roof and bottom being left. George’s Creek District, Md.— Fig. 13 shows the method used in the George’s Creek field, Maryland. The coal shows no indication of cleats, and the butts and headings can be driven in any direction. The main heading is driven to secure a light grade for hauling toward the mouth. Cross- headings making an angle of 35° to 40° are usually driven directly to the 298 METHODS OF WORKING. rise, and of the dimensions shown. Pillars are drawn as soon as the rooms are completed, being attacked on the ends and from the rooms on either side, the coal being shoveled to the mine car on a track in the room. Very- wide pillars are split. No effort is made to hold up the overlying strata, and the entire bed is removed as rapidly as possible. An extraction of 85$ of the bed is considered good work. A section of the seam is as follows: Roof coal, 10 in.; coal, 7 ft.; slate, i in.; coal, 10 in.; slate, 1 in.; coal, 10 in.; fireclay; slate. The top bench is bony and frequently left in place to prevent disintegration of the roof by the air. Above this coal is from 8 to 10 ft. of “rashings,” consisting of alternating thin beds of coal and shale, that is very brittle, and requires considerable timber to keep it in place.— (“ Mines and Minerals,” Vol. 19, page 422.) Blossburg Coal Region, Pa.— Coal is generally mined from drifts, but in a few cases by slopes. Fig. 14 shows the general method adopted; the breasts are run at right angles to the slips; the breast pillars are split by a center heading and taken out as soon as the breasts are finished. The gangway pillars are taken out retreating from the crop or boundaries of the property. Fig. 15. The general average of the coal seams is not over 31 ft., accompanied by fireclay and some iron ore. The dip of the veins is about 3$. — (‘‘Mines and Minerals,” Vol. 19, page 126.) Indiana Coal Mining.— Fig. 15 shows the double-entry room-and-pillar method as used in Indiana. The entries are generally 6 ft. high, 8 ft. broad, IOWA METHOD. 299 the minimum height required by law being 4 ft. 6 in. The rooms are from 21 to 40 ft. in width. The mines are generally shallow. The rooms m Fig. 15 are shown as widened on both ribs, but a more usual method in this locality is to widen the room on the inbye rib, leaving one straight rib for the protec- tion of the road in the room.— (“ Mines and Minerals,” Yol. 20, page 202.) Iowa Coal Mining.— The coal lies at a depth of 200 ft. below the surface, and is geologically similar to that of the Missouri and Illinois fields. It lies in lenticular basinsextending northwest and southeast and outcropping in the larger river beds. The seams are practically level, non-gaseous, and gen- erally underlaid by fireclay and overlaid by a succession of shales, sand- stones, and limestones, which are generally of a yielding nature, giving a strong, good roof for mining. There are three distinct seams, the lower one, which varies from 4 to 7 ft. in thickness, being the only one worked. The coal is a hard, brittle, bituminous coal that shoots with difficulty, but is excellent for steam and domestic uses. About Centerville, the coal has a distinct cleat, but elsewhere in the State this is lacking. The entry pillars along the main roads are 6 to 8 yd. thick, for the cross-entries 5 to 6 yd., and for the rooms 3 to 5 yd. Room pillars are drawn in when approaching a cross-cut. Both room-and-pillar and longwall methods are in use, with modifications of each. In the ro 9 m-and-pillar system, the double-entry system is almost invariably used in the larger mines. Rooms are driven off each entry of each pair of cross-entries at distances of 30 to 40 ft., center to center; the rooms are 8 to 10 yd. m width, and pillars 3 to 4 yd. The rooms are narrow for a distance of 3 yd., and then widened inbye at an angle of 45° to their full width. They vary from 50 to 100 yd. in length, and the road is carried along the straight rib. When double rooms are driven, the mouths of the rooms are 40 to 50 ft. apart, and they are driven narrow from the entry a distance of 4 or 5 yd. Fia 16. A cross-cut is then made connecting them, and a breast 16 yd. wide is driven up 50 to 60 yd. The pillar between each pair of rooms is 12 to 15 yd. In pillar-and-stall work, the stalls are usually turned off narrow and widened inside, the pillar varying from 5 to 8 yd. The stalls are 30 to 40 yd. in length, and the pillars are drawn back. When the stalls are driven m pairs, the pillar 8 to 10 yd. in width is carried between them. Longwall . — The main haulage road runs in each direction from the foot of the shaft, and on both sides of this diagonal roads are turned at an angle of 45°, or parallel to the main haulageway. These are spaced 10 yd. apart and driven 50 to 60 yd., when they are cut off by another diagonal road. Panel breasts are used where the conditions are such as to induce a squeeze. Rooms are turned narrow off entries and are arranged in sets of 6 to 12 rooms, with a pillar 10 to 20 yd. wide between the sets of rooms. When the rooms have progressed a short distance from the entry, they are connected by cross-cuts, and the longwall face is carried forward from this point. Packs are built and the roof allowed to settle, as in longwall. The wide pillars are taken out after the roof has settled. 300 METHODS OF WORKING. Ventilation :— The system of ventilating the workings usually employed is that of conducting the air to the inside workings by means of an air-course forming the back entry of each haulage road. From this point it is carried along the face of the rooms, through the breakthroughs or cross-cuts in the room pillars, returning thence to the haulage road, which is usually made the return airway. When, however, the mine is ventilated by means of a furnace or an exhaust fan, the intake airway is usually made the haulage road, in order to avoid doors at the shaft bottom. The Tesla, California, method is shown in Fig. 16. The coal seam averages 7 ft, of clear coal, and pitches 60°. This system was adopted m a portion of the mine to get coal rapidly: for, at this point, a short-grained, slate cap rock came in over the coal, making it difficult to keep props in place. The floor is a close blue slate and has a decided heaving tendency. The roof is an excellent sandstone. There is a small but troublesome amount of gas. Two double chutes are driven up the pitch at a distance of 36 ft. apart, con- nected every 40 ft. by cross-cuts. One side of each chute is used for a coal chute and the other for a manway and air-course. At a distance of 12 yd. apart small gangways are driven parallel with the main mine gangways. These are continued from each chute a distance of 300 ft., if the conditions warrant it. The top line is then attacked from the back end and the coal is worked on the cleavage planes; the breast, or room, therefore consists of a 12-yd. face, including the drift or gangway through which the coal is carried to the chutes; a rib of coal (2 or 3 ft.) is left between the breasts to keep the rock from falling on the breast below. Thus in each breast the Fig. 17. miners have a working face of about 15 or 16 yd., and as the coal is directed to the car by a light chute, moved along as the face advances, the coal is delivered into the cars at small cost, and but little loss results from the falling coal, as a minimum of handling is thus obtained. Immediately above each gangway, and starting from these main chutes, an angle chute is driven at about 45°, connecting with the breast gangway above it, and into these chutes the coal from that breast is delivered, runs into the mam chute, and from it is loaded into the mine cars in the main gangway. These angle chutes serve as a means of keeping the main chute full, and at the same time giving each breast an opportunity to send out coal continuously. Thev also serve the purposes primarily intended, of saving the coal from breakage, by giving it a more gradual descent into the full chute, me breast gangways are driven 5 ft. wide. No timbers are needed in these gangways, as they are driven iu the coal, except ou the foot-waU or floor TESLA METHOD. 301 side, which, as before stated, is a firm sandstone. It is found safest to leave a rib of coal on the top of the breast 2 or 3 ft. thick, until the working- face has passed on 12 or 15 ft., when this rib is cut out and thus all the coal extracted, the roof caving behind and filling in the opening. As cross-cuts are driven every 36 ft., ventilation is kept along the working faces, and a safe and effectual means of securing all the coal in the seam is thus attained. Fig. 17 shows another system used in No. 7 vein at the same place. The seam averages 7 ft. of coal. The roof is shelly and breaks quickly, hence the coal must be mined rapidly. In this system the gangway chutes are driven at right angles with the strike of the seam, 40 ft. up the pitch; a cross-cut 5 ft. X 6 ft. is then driven Fig. 18. parallel with the gangway. From this cross-cut, chutes are driven at same distance apart as the gangway chutes (30 ft.), at an angle of 35°, and cross- cuts are driven every 40 ft. between chutes, for ventilation. After a panel of five or more chutes is driven up the required distance, work is com- menced on the upper outside pillar and the pillars on that line are drawn and the next line is attacked, and this is continued until the panel or block is worked down to the cross-cut over the gangway. About every 80 ft. in this level it is found advantageous to build a row of cogs parallel with the strike of the seam as the pillars are drawn. This serves to save the crushing of the pillars, and prevents any accidents from falls of rock. But few timbers are required by this system.— (“Mines and Minerals, ” Yol. 19, page 145.) 302 METHODS OF WORKING. New Castle Colorado, Method.— The following method as described by Mr. R M Hosea * Chief Engineer of the Colorado Fuel and Iron Co., is used at New Castle Colo for highly inclined bituminous seams. The coals mined are only feirly hard, contain considerable gas, and make much waste in mining Fig - 18 shows the method used for extracting the Wheeler or thicker* veinto its ful 1 width of 45 ft., and the E seam 18 ft. thick, excepting that left for pillars. Rooms and pillars are laid out under each other m the two seams whenever practicable. Entries are along the foot-wall, 30 it. un the pitch is an air-course. Rooms and breasts are laid out as shown in B and C Fig. 18. In the Wheeler vein, the manways go through the entrv pillars to the air-course and thence along the ribs each side of the room one manway to the main entry serving for two double rooms. A lower bench of 6 ft. is first mined the full length of the rooms, 120 ft., side man wavs being protected by vertical or leaning props, bordered with 3 planks outside and the chute or battery is then put in. At the top the rooms arrconnected by cross-cuts, and, occasionally, intermediate cross-cuts are reauired The room is kept full of loose coal, only sufficient being drawn to keen the’ working floor at the proper height for the mining. When driven to the limit and^ with cross-cuts connected, the coal is all dra\vn out at the chutes which have receptacles for rock and waste at their sides, to be picked out by the loaders. The next operation is to dnve across the seam at Fig. 19. the air-course until the hanging wall is reached, manways, called back wan- t 4“ be°ng mrnteined as before. A triangular section of coal is mined off, as shown in A, Fig. 18, and the room filled with loose coal. The full thick ness of the seam is now taken off*, shots being first placed at S S, coa | drawn out at the bottom as required. Section D, Fig. 18, shows a method of robbing a pillar. In doing this, the manways are moved back into the uillar each side 10 ft. or so, by mining on the lower bench as before, and E 0 ies are drilled into the roof with long drills, which bring down as much of ^eo^erhanging 1 ^^ as can be reached.-(“ Mines and Minerals, 1 Yol. 17, page 377.) MODIFICATIONS OF LONGWALL METHOD. Fig 19 shows a good arrangement of the main and temporary haulage- wavs in a fiat seam The chief object in any plan of longwall workings is to w! the permanent roadways the arteries of the system, providing the most toect route^rom 11 aU° sections of the mine to the shaft. The temporary LONG WALL METHOD . 303 roads or working places are only maintained for a distance of 60 to 100 yd., until cut off by subroads branching at regular intervals from the main roads. In the figure, full heavy lines indicate the permanent haulageways, except only the main intake airway (12 ft. wide), running west from the downcast shaft D , and the main return air-course (12 ft. wide) leading from the face on the east side to the man- way around the upcast U, which is the hoisting- shaft. The full light lines indicate the diag- onal subroads, driven to cut off the working S laces, shown by the otted lines. The stables are located as shown in the shaft pillar, between the two shafts, where they will not contami- nate the air going into the mine, but will receive air fresh from the down- cast and discharge it at once into the upcast cur- rent. This position also affords ready access from either shaft in case of accident, and for the handling of feed and refuse. The pumps may be located in any con- venient position at the foot of the upcast. The shaft bottoms are driven 14 ft. wide nearly through the shaft pillar, and are r A __ [Three ', ! Sp/iff'' '• L1/7& Fig. 20. Wor/rec/. Oaf MB continued 10 ft. wide north and south through the gob. The width of all other roads and subroads is made 8 ft. The Fig. 21. extra width of the straight road through the hoisting shaft is to provide for the future need, when the size of the workings will demand that the mine be ventilated in four sections or splits; and these two roads will then each form the return of two sections. This will be accomplished by over- casting the main road forming the shaft bottom, and carrying half the cur- rent by this means to the east face, where it is again divided. The same thing is done on the west side. The divided currents, after traversing the faces of their own respective sections, unite and return to the hoisting shaft by the main haulage road. When the roof is very solid, the gob roads turn off the entries at 45°, and 304 METHODS OF WORKING. maybe a considerable distance apart, so that the tracks can be turned in along the working face and the mine cars loaded at the face. Whenthe roof is tender, making it impossible to maintain sufficient room for the mine cars to pass along the face, gob roads are turned off near together, and the mine cars run to the road heads, to which points the coal is shoveled or hauled in buckets. When the working face has reached such a distance from the bottom of the shaft that it becomes impossible to work rapidly enough to avoid the destructive weighting action of the roof, the mining must be divided into panels or sections, the working face of each of which can be advanced at the proper rate. . . . ,, , Figs 20 and 21 show a plan and section, respectively, of two methods largely* used in Europe for working thick pitching, contiguous seams of hard long-grained coal. From the foot of the shafts, levels are driven on the strike, and jig roads turned off these in the top seam at right angles up the pitch. The working faces are advanced in the same horizontal plane, the lower one being always ahead. The coal from the two lower seams is run through horizontal passages to the upper seam, where it is lowered to the levels below by means of jigs or gravity planes The slates between the seams and the refuse obtained in mining are used to fill m as the faces advance. This gobbing must be done quite thoroughly, m order to prevent excessive settling of the roof and consequent crushing of the coal at the faces. Where spontaneous combustion is liable to occur, it is not advisable to use this method, but rather that shown in the lower portion of the figures. Slopes, or inclined planes, are driven down the pitch from the levels to the basin, or, if possible, to the boundary line, where the working faces are formed by driving levels to the right and left of the ends of the slopes. The working faces are here also kept in a horizontal plane with the lower one farthest up the pitch. The coal from the two upper seams is taken through tunnels or flats to the slopes in the lower seam, and hoisted to the shaft bottom. Here all the inclined planes or other passages are mthe solid coal, and the worked-out places are left behind. A very small amount of coal is left in the mine when worked from the basin upwards, and the effects of squeezes are not felt to any great extent, as the weight of the roof is thrown on the gob. Where there is not sufficient refuse material to fill in with, it is taken into the mine from the surface, or from another adjacent mine having an extra amount of stowing material. . _ It is not necessary that the slopes be sunk to the boundary line, m which case the main-slope pillars should be large and left in so that the dip workings , as they are called, can be continued downwards when desired. In this way, the first cost of opening up is greatly reduced. The ventila- tion of these workings is quite simple, the intake being split at the ends of the main entries, or slopes, and the air forced along the different working faces to the right and left, and thence to the upcast by way of the main-return airways. If at all possible, it is advisable to provide an outlet near the faces of the rise workings that are advancing upwards, because the lighter gases cannot be forced down-hill with satisfaction unless an excessive velocity of the air-current be maintained. These systems are well adapted to deep or shallow mines, and to give maximum outputs for minimum development, provided the work is carried on quickly and steadily. Overhand-Stoping Method.— Where several thick and heavily pitching seams, in which considerable firedamp is given off and the roof falls freely, are to be worked, a shaft is sometimes sunk m the adjacent strata, and at certain distances horizontal tunnels are driven to the coal seams. From these tunnels, levels or haulage roads are driven m each seam to the right and left, provided the seams are not so close together as to make it more profitable to use rock chutes or tunnels, through which the coal is run from one seam into the other. At certain intervals, depending on the length of the lifts horizontally, pairs of headings, usually called dtps, are driven up the pitch until they intersect the levels and tunnels above. Headings are turned off these dips to the right and left, parallel to the mam levels or haulage roads, and when they meet or have reached their limit horizontally they are holed, or cut through, by cross-cuts driven on the pitch. The working faces thus formed are then carried back, as shown in Fig. 22. Skips are taken off the face and the roof allowed to cave in after each operation and fill up the gob behind. The order of working is such that the top faces are worked in advance of the lower ones. The cars, which are taken to the working faces, are handled in the dips by balance carriages, or back balances , as they are termed in some localities,. I he ANTHRACITE MINING. 305 barney, or balance, runs on a narrow track in the middle of the track for the carriage on which the car is placed. The barney will raise the carnage with the empty car on it, and the carriage and loaded car will hoist the barnew These gravity planes are only made one-half the length of the dips, or about 150 ft., in order that greater safety may be secured and shorter ropes used. One is placed in the lower half of one of the pairs of dip headings, and another in the upper half of the other, thus necessitating that the cars be changed from one gravity plane to the other midway along the dips. This is done by taking the car off one carriage and pushing it through a break- through or cross-cut to the other. Fig. 22 shows the method of working these lifts in some parts of England and Belgium where the seams are gaseous, and some of them quite thick. The face is stepped more or less deeply, depend- ing on the pitch, in order to protect ea,ch miner from the falling coal of his neighbor. The men reach the higher portion of the working face through timbered manways. The coal is generally run down chutes to the cars below, but in some places it is run to the end of the gangway below by means of inclined chutes, or spouts, laid on the gob. The essential feature for the successful operation of this system is the close and careful stowing of the gob between walls. In Belgium, cord wood and brush wood are very largely used for gobbing material or stowing between the regular timbers. All the coal, except very thin vertical pillars, is taken out. Where there is Fig. 22. much firedamp, the miners simply nick the coal and leave it stand over night during which time the gas either forces it off the solid or so loosensit that the miner can easily take it off with a pick. (See also Highly Incline Mineral Deposits.) , METHODS OF MINING ANTHRACITE. A perfectly flat seam of anthracite is seldom found in America, and even where a portion of the seam maybe found lying comparati^ sudden changes in dip must be expected that a system adapted to working on a pitch is almost universally used. A breast may start on a How _ pitch au d the pitch may increase gradually until it beeves vertical, or Pj? may be the case. The cleat is usually lacking m anthracite and the direc- tion of driving the breasts is determined largely by the pitch and by haulage COI For^hches up to 30°, the methods shown in Figs. 1,7, 8, 9, 10, 12, and 13 are, in general, applicable, with certain changes due to local considerations. There is considerable difference in the methods of opening rooms m anthra- cite and bituminous mines, owing to variations in thecharac^ coals and to the fact that anthracite will slide on chutes of 1 ^ s o 1 ^ 1 "^ tl a ° T 5 than bituminous coal. Where the pitch does not exceed 4Jthewoingm turned off at right angles to the gangway. In moderately thick . & oal i seams, pitching between 4° and 18°, the rooms are generally driven forming room breasts, thus securing a grade that permits the haulage of the cars to the face. 306 METHODS OF WORKING. There are two methods of mining thick coal in breasts when nearly flat. (1) The breasts are opened out and driven to the limit in the lower bench of coal, and the top benches are blown down afterwards, beginning at the face and working back. (2) When the roof is good and there is no danger of its falling and closing up the workings, the upper benches may be worked in the opposite direction, beginning at the gangway and driving towards the limit of the lift, or the working of the upper bench may follow up that of the lower bench. When the seam is less than 12 ft., the top is supported by props; in thicker seams, the expense is so great for propping that but little attempt is made to support the roof. In the thicker anthracite seams (notably the Mammoth), the coal in the breasts is so worked as to make an arch of the upper benches of coal, which acts as a temporary support for the roof, the coal in the arch being extracted when the pillars are robbed. When the inclination of anthracite seams is less than 30°, the breasts may be opened with one chute in the center, which ends in a platform projecting into the gangway, off which the coal can be readily loaded into the mine car. When this method is employed, the refuse is thrown to either side of the chute. If the pillars are to be robbed by skipping or slabbing one rib only, it is well to keep most of the refuse on one side. Sometimes, when the top is good, and the breasts are driven wide, two chutes are used, but the cost of making the second chute is considerable and is therefore not advisable unless necessitated by the method of ventilation employed. Col. Brown’s Method.— Fig. 23 shows a panel system devised by Col. D. P. Brown, of Lost Creek, Pa., wiiich gives good results in thick seams pitching from 15° to 45°, where the top is brittle, the coal free, and the mine gaseous. Rooms or breasts are turned off the gangway in pairs, at intervals of about * Fig. 23. 60 yd. The breasts are about 8 yd. wide, and the pillar between about 5 yd. wide, which is drawn back as soon as the breasts reach the airway near the level above. In the middle of each large pillar between the several pairs ot breasts, chutes about 4 yd. wide are driven from the gangway up to the airway above. These are provided with a traveling way on one side, giving the miners free access to the workings. Small Headings are driven in the bottom bench of coal, at right angles to these chutes, and about 10 or 20 yd. apart. These headings are continued on either side of the chutes until they intersect the breasts. When the chute and headings are finished, the work of getting the coal in the panel is begun by going to the end of the upper- most heading and widening it out on the rise side until the airway above is reached and a working face oblique to the heading is formed. This face is then drawn back to the chute in the middle of the panel. After the work- ing face in the uppermost section has been drawn back some 10 or 12 yd., work in the next section below is begun, and so on down to the gangway, working the various sections in the descending order. Both sides of the pillar are worked similarly and at the same time toward the chute. Small cars, or buggies, are used to convey the coal from the working faces along the headings to the chute, where it is run down to the gangway below and loaded into the regular mine cars. This system affords a great degree of safety to the workmen, because whenever any signs of a fall of roof or coal occur, the men can reach the heading in a very few seconds and be perfectly safe. A great deal of narrow work must be done before any great anthracite mining. 307 Quantity of coal can be produced. The breasts are driven in pairs and at intervals, to get a fair quantity of coal while the narrow work is being done, and they are not an essential part of th,e system It is claimed that the facility and cheapness with which the coal can be mined, ^ cleaned in the mine more than counterbalance the extra expense for the nal B a tte ry°Work i n g. — Fig. 24 shows a method of opening a breast by two chutes c/c, when there is a great amount of refuse, or when a great amount Fig. 24. 25. are of £?as is given off. The chutes are extended up along the rib to mthm fewfeet If the working face, either by planking carried ^upright posts, or by building a jugular manway, as shown inthe sections (a) and (5), Fig. These chutes, built of jugulars or inclined props and faced by 2 plank, made as nearly air-tight as possible, to carry the air from the heading a to the working face. Fig. 24 shows a breast on a pitch too steep to enable the miner to keep up to the face. In seams of less than 35° the platform / shown near the face ot the breast is unnecessary, and in seams thicker than 12 ft. it cannot be built; hence, this method of working is applica- ble (1) to beds pitching more than 35°, and (2) to thin seams. The coal is separated from the refuse on the platform /, and is run down the manway chutes and loaded into the cars from a platform projecting into the gang- way g. The refuse is thrown in the middle of the breast behind the platform. A cer- tain amount of coal is kept on the plat- form to deaden the blow from the falling coal. The chutes are timbered when the character of the coal requires it. This plan can also be employed in thick seams refuse’ tcf fin\ InT center^/ the breast so that the miner can work without the Pla Fig. I 25 (a) is a section through p,p when jugulars a, a areusedtoform the manways b, b along the sides of the breast; and (5) is a section through the 308 METHODS OF WORKING. same line when upright posts a, a are used to support the plank in forming the manways b, b. The refuse in these eases only partially fills the gob. In working very thick seams op heavy dips, where there is not enough refuse to fill the middle of the breast, the miner has nothing to stand on, the l Plan along ts. Fig. 27. Section on pq. platform being impracticable; therefore, it is necessary to leave the loose coal in the breast. Loose coal occupies from 50 $ to 90$ more space than coal in the solid. This surplus is drawn out through a central chute. If the roof ANTHRACITE MINING. 309 is poor, the movement of the coal will not in this way cause it to fall ano mix with the coal; and if the floor is soft, the jugulars, which are stepped into the floor, are not so liable to be unseated, closing the manway and blocking the ventilation. The surplus is sometimes sent down the manways, leaving the loose coal in the center of the breast undisturbed, until the limit is reached. Single-Chute Battery.— To prevent the coal from running out through the chutes, the opening into the breast is closed by a battery constructed by laying heavy logs across the openings, as shown at b, Fig. 26, or else built on props, as shown at b , Fig. 27; a hole is left in the center, or at one side of the battery, through which the coal may be drawn. The battery closes all the openings into the breast, except the space occupied by the jugular manways, and is made air-tight, or as nearly so as possible, by a covering of plank. Fig. 26 is a plan and section of a breast opened up by a single chute. The plan A is taken on the line m n shown on the section B , which section is taken on the line / 1 shown on the plan A. The pitch is great and the seam is so thick that the breast must be kept full of loose coal for the men to work upon, the surplus being drawn off at the battery b and run into the car standing on the gangway g through the chute c. A manway w is made along each side of the breast, for the purpose of ventilation and affording a passage for the men to reach the working face. The heading a is used for an air- course between breasts. The main airway h is driven over the gangway g , where it will be well protected. By drawing the surplus coal through a central chute,- the manways are not injured so much as when it is drawn off through side chutes, as the coal will move principally along the middle of the breast. When the breast is worked up to its limit, all the loose coal is run out of the breast and the drawing back of the pillars is commenced, unless for some purpose they are allowed to stand for a time. Double-Chute Battery.— Fig. 27 shows a plan and section of double-chute breasts used in very thick seams having a heavy dip. The breasts are entered by two main coal chutes c, c, each of which is provided with a battery 6, through which the coal is drawn. A manway chute rri is driven up through the middle of the pillar for a few yards and is then branched in both directions until each branch (slant chute) intersects the foot of a breast near the battery b, as shown. The jugu- lar manways n, n are started at this point and continued up each side of the breast. The main airway h is driven in the solid through the stump A above the gangway. By driving the main gangway g against the roof, as shown, the pitch of the chute is lessened, and the loading chute c is more readily controlled. When the main gangway is not driven against the roof, a gate is placed in the chute below the check-battery, which enables the loader to properly handle the coal. Coal in excess of the amount necessary to keep the miner up to the face may be drawn through the main battery, or sent down the manway chute, from which it is loaded through an air-tight check-battery. The main chutes are usually 8 or 9 ft. wide, but sometimes only for the first 6 or 8 ft.; above this they are driven about 6 ft. square. The manway and slant chutes are also about 6 ft. square. When the seam is not thick enough to carry the return airway h (Fig, 27) over the gangway, the chutes are driven up in the same manner as in Fig. 27, for a distance of about 30 ft., where they intersect the airway. The breast is opened out just above the airway, a battery being built in the airway Fig. 28. 310 METHODS OF WORKING. immediately above each chute. A manway is driven from the gangway up through the middle of the stump until it intersects the airway, and a trap door is placed at this point to confine the air. This manway is made about 4 ft. X 6 ft., or smaller. . . . Fig. 28 shows a less complicated plan than Fig. 27. The main chutes n, n are driven up to the heading c, from which the breast is opened out; a log battery is built at the top Fig. 29. of each chute at the points marked a, a. The chutes are used for drawing the battery coal, and for re- ceiving the manway coal, and are also used for trav- eling ways. A check-bat- tery b is placed in the chute to prevent the air-current from taking a short cut from the gangway through the chute to the breast air- ways. This check-battery is of great assistance to the loader when the chute has a very steep pitch, as he can readily control the flow of coal through the draw- hole. All these methods are open to the objection that in case of any accident to the breast manway, by which the flow of air, shown by the arrows, is obstructed, there is no means of isolating the breast in which the accident occurs, and the venti- lation of all the breasts beyond it is entirely stopped. To overcome this, sometimes the pil- lar A, shown in left- hand breast, Fig. 28, is left in each breast to protect the airway. Rock-Chute Mining. Fig. 29 shows a section of two seams, sepa- rated by a few yards of rock. Chutes from 4i to 7 ft. high and 7 to 12 ft. wide are driven in the rock from the gangway or level g to the level l in the seam above, at such an angle that the coal will gravitate from the upper seam into the gangway g. The work- ing, otherwise, is sim- ilar to that previously described. Rock-chute mining contemplates the fol- lowing sequence of operation; 1. The opening of all gangways and air- ways in the lower seam, lying a few feet above it. Fig. 30. to develop coal as yet untouched in a thick seam ANTHRACITE MINING. 311 2. Developing the thick bed by a regular series of rock chutes driven from the gangway below; workings being opened out from chutes as in ordinary pillar-and-breast working — the panel system or some other plan may be found better than pillar-and-breast workings 3 Driving the breasts to the limit of the lift and robbing out the pillars from a group of breasts as soon as possible, even if a localized crush is induced. 4 After one group of breasts is taken out and the roof has settled, open- ing a second series of chutes for the recovery of coal from any large pillars that were not taken out when the crush closed the workings. 5. While the work of recovering the pillar coal is in progress, a second group of breasts may be worked, and the process continued until all the area to be worked from that gangway has been exhausted. The same process is employed in opening lower lifts. , , 6 When all the upper bed of coal has been exhausted, the lower seam may be worked by the ordinary method. Workings in this seam may be Fig. 31. carried on simultaneously with the upper bed, but to avoid the possibility of a squeeze destroying these workings, very large pillars must be left. After exhausting the upper seam, these pillars may be advantageously worked by opening one or two breasts in the center of each, and when these are worked to the upper limit, attacking the thin rib on each side, com- mencing at the top and drawing back. . , When the roof of the lower bed is good, the cost of timbering and keeping open the gangways and airways will be considerably less than if these were driven in the upper seam, and this difference, in some cases, may be suf- ficient to pay for driving all the rock chutes. . There are three undetermined points in this connection, viz.: (1) The 312 METHODS OF WORKING. maximum distance between the two beds, or the length of rock chute that can be driven with satisfactory financial results. (2) The maximum dip on which such working can be successfully opened. (3) The maximum thick- ness of the upper and also of the lower seam, which w T ill yield results war- ranting the additional outlay w'hen rock chutes are of considerable length. Fig. 30 show's how one or more seams are worked by connecting them by a “stone drift,” or “tunnel,” driven horizontally across the measures, through w hich the coal from the adjacent seams is taken to the haulage- way leading to the landing at the foot of the slope or shaft. Tunnels are sometimes driven horizontally through the measures from the surface, so as to cut one or more seams above water level. The low r er seam of coal is w r orked from a gangw ay or level l, connected by a tunnel, or stone drift t, to the level or gangway g, in the thick seam, The stone drift may be extended right and left to open seams above and below' the thick seam* This tunnel, or stone drift, is never driven under a breast in the upper seam, but directly under the middle of the pillar. In the upper and thicker seam, when the coal is very hard, a breast 5 is worked to the limit and the loose coal nearly all run out through the chute s into the gangw ay g. The “ monkey gangway ” m is driven near the top as a return airway, and is connected to the upper end of the chute s by a level heading n, and to the main gangw ay g by a heading v. These headings are driven for the purpose of ventilation and to provide access to the battery in case the chute s should be closed. In the lower seam, the breast is still being w orked upwards in the ordinary way. The J. L. Williams method of working anthracite, Fig. 31, has been applied successfully by the originator at the Richards Mine, Mt. Carmel, Pa. ; and by it 90£ of the available coal is said to have been obtained. The method is a pil- lar-and-stall method with the folio w T ing distinguishing points: (a) Timbering the gob with props set not more than 6 ft. apart, to keep up the roof during the extraction of the pillars. (6) Making holes from the crop, for the delivery of timber into the workings, (c) Removing the pillars in shorter lifts than is possible w hen the roof is supported with culm pillars. ( d ) Keep- ing the gob open with timber for dumping the fallen rock, that would have to be sent to the surface if the breasts were flushed. Both the floor and the roof of the mine were weak, so that it w'as not possible to make either the breasts or the pillars wide. In some cases, the floor consisted of 3 ft. of clod, and to prevent its lifting and sliding, every alternate pronwas put through the clod and its foot set in the slate beneath, while the other props were set on pieces of 2" plank 2 ft. in length to keep down the bottom. A small gangway X is driven to take out the chain pillar, and Y is a small gangw ay for taking in timber. Running of Coal.— In large seams, when the coal is soft and shelly 91* slip- pery and lies at an angle of more than 50°, and generates large quantities of firedamp a danger to be guarded against is the sudden liberation of gas should a breast run; that is, should the coal at the face loosen and run out bv its own gravity, only stopping w'hen it chokes or fills up the open space below To meet these conditions, the air-course maybe driven above the gangway and used as a return, the fan being attached as an exhaust, and the working breasts ventilated in pairs. The inside manway of one of a pair of breasts is connected with the gangway for the intake, and the outside manwav of the other breast with the return airway, giving each pair of breasts a separate split of the current. In collieries where this system of working is folio w T ed, the coal is soft. A new T breast is worked up a few ^ ards, but as soon as it is opened out, the coal runs freely and the manways are pushed up on each side as rapidly as possible, to keep up with the face. Two miners one on either side, sometimes finish a breast without being able to cross to each other. The work is done exclusively with safety lamps, and when a breast “runs” the gas is liberated in such quantities that it frequently fills breasts from the top to the airway before the men can get down the'manwav on the return side. When the gas reaches the cross-hole, it passes into the ‘return airway without reaching any part where men are working. Should a run of coal block a breast by closing the manway, it affects the current of one pair of breasts alone. As the gangway is the intake, leakage at the batteries passes into the breasts, as the cross-holes are above their level and the gas is thus kept above the starter when at the draw-hole. The gangway, chutes, and airway are supplied by w-ooden pipes, w r hich connect with a door behind the inside chute. If a breast runs up to the surface, it does not affect the return airway, as it is in the solid,. ANTHRACITE MINING . 313 Among the disadvantages urged against this system of working are the f<)1 ItTncfeases the friction, as the air must pass in the airway all the distance from the breast to the fan, the area of the airway being small in comparison t0 ilis t^faces of the breasts are so much higher than the return airway, the lighter gas must be forced down into the return against the buoyant power of its smaller specific- gravity. The reduction of friction obtained by splitting is neutralized by each split running up one small manway and down another; the advantage of running through several pillar headings and thus securing a shorter course being lost. This can be partly obviated by ventilating the breasts in groups, but the dangers avoided in splitting are increased. Blackdamp, which accumulates in the empty or partly empty breasts, works its way down and mixes with the intake current, as there is no return current in the breast strong enough to carry it away, the return being closed in the airway. . ^ , All things considered, when the seam is soft and has a pitch of 40° and upwards, and emits large quantities of gas in sudden outbursts, as in running breasts, this system is the best that can be adopted. When the Coal Is Hard and Gas Is Not Freely Evolved.— The reverse of the svstem just described is followed at some collieries where the coal is hard and but little gas is encountered. The airway is driven over the gangway or against the top, the fan being used to force the air inward to the end of the airway. The air is distributed as it returns, being held up at intervals by distributing doors placed along the gangway. Among the advantages claimed for this plan are the following: ■ As the pressure is outward, it forces smoke and gas out at any openings that may exist from crop-hole falls or other causes. The warm air from the interior of the mine returning up the hoisting slope or shaft prevents it from freezing. As the current is carried from the fan to the end of each lift without pass- ing through working places, the opening of doors as cars are passing, etc. does not interfere with the current. . If a locomotive is used, the smoke and gases generated by it are carried away from the men toward the bottom. Locomotives are generally used only from the main turnout to the bottom. An objection to this svstem is that the gangway, as the return, is apt to be smoky. Starters and loaders are forced to work in more or less smoke, and even the mules work to disadvantage, while if gas is given off, it is passed out over the lights of those working in the gangway. However, in places where there is but little gas, and airways of large area can be driven, this plan works very satisfactorily, and some of the best ven- tilated collieries are worked upon it. . An objection advanced by some against forcing fans is that they increase the pressure, thus damming the gas back in the strata. In case the speed of the fan is slacked off, the accumulated gas may respond to the lessened pres- sure and spring out in large volumes from its pent-up state. This argument, however, works both wavs. An exhaust fan running at a given speed is taking off pressure, and if anything occurs to block the intake, the pressure is diminished, and the gas responds to the decrease on the same principle. Hints for the Smaller Seams When They Are Small and Lie From Horizontal to About 10°. — ' Two gangways may be driven, the lower or main gangway being the intake. Branch gangways should then be driven diagonally or at a slant, with a panel or group of working places on each slant gangway. Large headings should connect the panels. In this system, the air is carried directly to the face of the gangway and up into the breasts, returning back through the working places. The intake and return are separated by a solid pillar, the only openings being the slant gangways on which are the panels. The advantages of this plan are several: The main gangway is solid, with the exception of the small cross-holes connecting with the gangway above; these furnish air to the gangway and are small and easily kept tight. These stoppings* should be built of brick, and made strong enough to withstand concussion. A full trip of wagons can be loaded and coupled in each panel or section without interfering with, or detaining the traffic on, the main road; one trip can be loaded while another is run out to the main gangway for transpor- tation to the bottom. 314 METHODS OF WORKING. The only break in the intake current is when a trip of cars is taken out from, or returns to, a panel or section; this can be partially provided against by double doors, set far enough apart to permit one to close after the trip before the other is opened. This distance can be secured by opening the first three breasts on a back switch above the road through the gangway pillar, or by running each branch over the other far enough to obtain the distance for the double doors. If it is not desired to carry the whole volume of air to the end of the air- way, a split can be made at each branch road. These will act as unequal splits in reducing friction, and, although not theoretically correct, are prefer- able to dragging the whole current the full length of the workings. The objections urged to this plan are that it involves too much expense in the large amount of narrow work at high prices necessary to open out a colliery, that it necessitates a double track the whole length of the lift, and that the grade ascends into each panel or section. But the latter criticism falls, because the loss of power hauling the empty wagons up a slight grade is more than made up by the loaded wagons running down while the mules are away putting a trip into another panel or section. For a large colliery this is without doubt the best and cheapest system. When the Seam is Small and Lies at an Angle of More Than 10°.— In small seams lying at an angle of more than 10°, and too small to permit an airway over the chutes, it is more difficult to maintain ventilation. If air holes are put through every few breasts, and a fresh start obtained by closing the back holes, or if an opening can be gotten through to the last lift as often as the current becomes weak, an adequate amount of air can be maintained, because the lift worked can be used as the intake, and the abandoned lift above as the return. To ventilate fresh ground, the filling of the chutes with coal will have to be depended on, or a brattice must be carried along the gangway. This can be done for a limited distance only, as a brattice leaks too much air. As a rule, collieries worked on this plan are run along until the smoke accumulates and the ventilation becomes poor; then a new hole is run through and the brattice removed and used as before for the next section. This operation is repeated until the lift is worked out. Some- times, to make the chutes tight, canvas covers are put on the draw' holes, but as they are usually left to the loaders to adjust, they are often very imperfectly applied. Then, as the coal is frequently very large, the air will leak through the batteries. This plan works very satisfactorily if the openings are made at short intervals, say as frequent as every fifth breast, but the distance is usually much greater to save expense. As the power of the current decreases as the distance between the air holes is increased, good ventilation is entirely a question of how often a cut-off is obtained. An effective ventilation could be maintained in a small seam at a heavy angle by working with short lifts, say two lifts of 50 yd. instead of one of 100 yd., as at present. The gangways should be frequently connected, and one used as an intake and the other as a return. This would necessitate driving two gangways where one is now made to do, but the additional expense would be made up in the greater proportion of coal won. FLUSHING CF CULM. From 15 $ to 20$ of the coal taken out of an anthracite mine, according to the methods used in the past, became so fine in the course of preparation through the breaker that it could not be used or sold, and had to be piled away as refuse. Recently, the coarser portions of these culm piles have been screened out and sold for use as steam sizes, while the finer part, together with the fine material from the breaker, has been carried back into the mines with water to fill the abandoned portions of the underground workings. This culm is carried through a system of conveyors to the hopper, usually an old oil barrel, and the stream of water is conducted into the same hopper by a 3" pipe. The culm is then carried by the water through a pipe from 4 to 6 in. in diameter, which passes into the mine through the shaft, bore hole, or other opening, thence alo-ng the gangways to the chambers through the cross-cuts, and to the point where it is desired to deposit the culm. The bottoms or outlets of the chambers to be filled are closed by board partitions fitted closely, or by walls of slate or mine rubbish. The culm, as it issues CULM FLUSHING. 315 from the end of the pipe, takes a very flat slope, and it is carried a long dis- tance by the water, which ultimately filters through the deposited culm to the lower portion of the mine, to be pumped to the surface. When the chamber is filled to the roof, the pipe is withdrawn and extended to the next place to be filled, and so on. Wrought-iron pipe is said to be the best, and the life of the pipe depends on the nature of the water used and the material treated. With fresh water and small culm from the buckwheat screen, it lasts 18 months; when carrying culm from the bank, ranging from dust to pea'coal and some chestnut, 9 months; and when mixed with ashes, 6 months. The smaller the material the better. The amount of water used depends on the distance to which the culm is carried and the slope of the pipe. , i From li to If lb. of water is required to flush 1 lb. of culm to level and down-hill places; 3 to 6 lb. of water to 1 lb. of culm to flush up-hill for heights varying from 10 to 100 ft. above the level of the shaft bottom. Any ele- vation of the pipe very materially increases the amount of water necessary. Mr James B. Davis, superintendent of the Dodson and Black Diamond mines, has ascertained by experiment that 1 cu. ft. of anthracite coal ground to culm can be flushed into a space of nearly 1£ cu. ft., and it is therefore impossible to compress the culm more than one-third. In addition to acting as a filling and a support, to prevent squeezes and crushing, flushing has been advantageously used for fighting and sealing off mine fires. No instance has been recorded where spontaneous combustion has taken place in the flushed culm. The Dodson culm* plant, which was a pioneer, cost $7,473.42, with the capacity of flushing 119 tons per day, while the Black Diamond culm plant is capable of flushing 287 tons per day and cost $6,280.12, but plants can probably be put up much more cheaply than this. The saving from the flushing of culm over depositing it on the surface varies for the ordinary anthracite colliery from $5 to $15 per day. The average cost of putting in stoppings in a 9' vein is given by Mr. Davis as $9.50, including material. To remove the pillars after the intervening breasts have been filled with culm, the face of the pillar along the gangway is attacked, and a road driven up through the pillar, splitting it (z, Fig. 32). This road may be the full width of the pillar, but in general it is necessary to leave a narrow stump of coal on either side to keep up the fine flushed material in the adjoining breasts. The thickness of this supporting coal depends entirely on the condition of the flushed material behind it. If that is fine, it will set firmly and form a compact mass that will not run. In such a case, the pillar may be entirely taken out, leaving a vertical wall of solidly packed flushed culm. When the flushed material is of a size larger than buckwheat, it will not set compactly, but will run when it is opened up, and when such material fills the adjoining breasts, the thin pillar of coal must be left to keep back the culm. Timbers are placed flush up against the culm or the coal stumps, as the case may be, and if there is a tendency for the culm to run, lagging is placed behind the timbers. In some cases, as much as 700 ft. of timber have been used per 100 ft. of pillar taken out. As the pillar is removed, the top settles until it finally rests upon the flushed culm, and as the weight from the top and the pres- sure from the sides comes upon these props, they are broken, while the coal that has been left will also be crushed. At the Black Dia- mond colliery, the props used are 16 ft. long, and at this colliery the top settles about 4 ft. if the flushed material is packed tightly before the roof pressure comes on it. After this settling, new props 12 ft. in length are put in close up against the culm and the broken stump of the original pillar, and they serve to keep the road open up to the working face. Fig. 32. 316 MINING MINERAL DEPOSITS. METHODS OF MINING MINERAL DEPOSITS. Much of what has already been given under the heading of Coal Mining applies equally to the mining of mineral deposits. It will therefore not be repeated under this heading, and the only methods here given will be those that have not already been covered. Highly inclined deposits are mined out as follows: Horizontal passages called drifts , levels , or galleries are driven through the ore at regular intervals, and connected by openings at right angles to the levels, which, in the case of perpendicular or highly inclined deposits, are called winzes or raises, according as they are sunk from above or raised from below. These parallel openings divide the ore body into a series of rectangles, thus serving to test its value. (See also Overhand-Stoping Method, page 304.) Levels. — The distance between the individual levels depends on the material being mined. They are placed nearer together in high-grade ore than in low-grade material. The width of the vein also has considerable influence on the distance between the levels. In veins where it is necessary to break into walls to afford working room in the levels, they are usually placed as far apart as is consistent with the economical handling of the material in chutes and convenient access to the working faces of the stopes. The distance between the levels varies from 60 to 100 ft., and should be measured on the dip and not perpendicularly. Winzes or Raises.— The distance between the raises or winzes varies from 30 to 250 ft., depending largely on the character of the material and the method of getting it into the chutes or winzes. Where the material at the working faces is shoveled or thrown directly into the chutes, they are often placed as close as 30 ft., while if the material is carried from the working face to the chute or winze in a wheelbarrow, the chutes may be much farther apart. Stoping.— For narrow deposits, there are two general styles of stoping in regular use, called, respectively, underhand and overhand stoping. There are several minor divisions under each. Underhand stoping may be conveniently divided into underhand regular and underhand Cornish. The regular method of underhand stoping is illustrated in (a), Fig. 33, and may be described as follows: The miner selects a place in any given level or on the surface of the ore deposit from which to commence stoping. A cut 6 or 7 ft. in depth and from 6 to 8 ft. in length is made. This forms the first, or No. 1, bench in the stope. After this, he continues the work in each direction, supporting the track, if any exists above, upon stulls or timbering. After this No. 1 bench has proceeded a sufficient distance, he starts a similar cut in the bottom of it, which forms No. 2 bench, and is driven in both directions as before. At first the ore can be shoveled to the level above, but after considerable depth has been attained, it will be necessary to provide a winze, as shown at /, through which the ore from the lower benches can be hoisted. Stulls covered with lagging are placed across the stope behind each bench as platforms, to support the waste material. Under- hand stoping by the Cornish system is illustrated in (6), Fig. 33, and differs from the system just described only in that the level below has to be driven first, and a winze sunk to it. a is the lower level, b the winze, and c the upper level. The work is then carried on in successive benches, as described. OVERHAND STORING. 317 The advantages of the Cornish method are that any water that collects in the stope flows to the lower level and does not have to be taken care ot in each individual stope. Also, the ore can be tumbled down through the raise to the lower level, thus avoiding the extra hoisting with a windlass, or small hoist. The advantages that apply to any system of underhand stoping are as follows: The ore can be extracted at once; while the stope is new, the miner is protected from the roof by stulls and stagings; the loss of fine and valuable mineral is reduced, owing to the opportunity for sorting afforded during the handling of the broken ore. The disadvantages are as follows: The manner in which the ore must be handled is expensive; an individual pumping plant will be necessary in each stope of a wet mine with the regular system; should the mine be abandoned for any length of time, the stulls become loose and allow the rock stowed upon them to fall on the face of the ore, rendering the mine unsafe, and burying the ore so as to require a large expenditure of time and money to reopen the workings; in a wet stope, the water flows down over the working faces, interfering with the workmen and forcing them to stand continually in water. . , _ _ Overhand Stoping.— In this system of stoping, the ore is broken down from above as the work progresses. Work is usually started from the bottom of a raise, as B, Fig. 34. After the lower level A has been driven, the miner stands on top of the lagging over the caps and works out a slice C 5 or 6 ft. high, this being followed by succeeding slices, as D and E. Chutes are timbered or cribbed at intervals, through which the material may be thrown down and any waste packed in the space between the chutes, as at F. In cases where the entire deposit is of value, a portion of the broken ore is allowed to accumulate as a platform upon which the men stand while Fig. 34. working, only enough being sent through the chutes to provide working room. After overhand stoping is started, the work may be carried on by means of breast holes, as shown at E. The force of gravity assists in break- ing the rock, and reduces the powder necessary for blasting. Where rich ore is broken, platforms of planks, or sheets of canvas or bull hide covered with plank, may be placed over the filling to receive the broken ore, thus preventing the loss of fine and valuable material in the filling. One argument which is usually presented against overhand stoping is that the roof is not secured by timbering, but this is offset by the fact that the workmen are always close to the roof and thus examine its condition and break off any dangerous portions or give them such support as may be needed with temporary timbers. Overhand stoping may be carried on in a number of modified forms, all of which involve the principle of breaking down the material in such a manner that thq work is aided by gravitation. Sometimes, where practically the entire deposit is removed, temporary platforms supported on stulls are con- structed close to the working face for the workmen. The advantages of overhand stoping are that no hoisting or pumping is required in the block of ore being worked, as with underhand stoping with- out a winze; water gives no trouble in the stopes; less timbering is required than in the underhand stoping, because no platforms are required to store waste, and the timbering in working stagings is usually recovered; where the mine is abandoned for a time, the working face is usually left in better 318 MINING MINERAL DEPOSITS. shape with overhand than with underhand stoping. In the overhand system, gravity assists in the breaking of the ore. The disadvantages are that the miner is forced to work under an unsup- ported roof, though the fact that he is close to it enables him to examine it and take care of any dangerous portions. There may be greater loss of the fine and valuable material that becomes mixed with the waste than in underhand stoping, though this may be largely prevented by the use of boards or canvas. Flat or Slightly Inclined Deposits.— Where flat or slightly inclined ore bodies are being worked, the working drifts (corresponding to levels in steeper deposits) are driven comparatively close together (about 30 ft. apart) and the material between them removed in successive steps, as in underhand or overhand stoping, the space behind the miner being packed with waste mate- rial to support the roof, or the roof being supported by timbering until the ore is removed. Sometimes pillars of ore have to be left to aid in the support of the roof, and when this is the case, the miners try to leave the pillars where the ore is low grade. When a deposit of ore is of uniform value throughout, and the roof of a somewhat flexible character, it may be let down without much, if any, stowing, as in the longwall system of coal mining. In other cases, the material is removed like square work or by pillars and rooms, the pillars in either case being robbed as closely as possible before leaving the workings. LARGE DEPOSITS OVER 8 FEET THICK. With a deposit much over 8 ft. in Fig. 35. The advantages are that it thickness, it is impossible to keep the walls in place by stulls or single sticks of timber. Large masses of mineral frequently contain very valuable ma- terial, and engineers have developed a number of methods for the removal of their valuable contents. The method depends largely on the value per ton of the material being removed, and local conditions as to the cost of labor, timber, filling material, char- acter of wall rock, etc. The methods used for these deposits are square work , filling , caving , and square-set timbering systems. Square work, also called the cham - ber-and-pillar system , is illustrated in Fig. 35. Galleries are driven through the ore as shown, the deeper galleries being smaller than the upper ones, the object being to leave larger pillars for the support of the material above the workings. Galleries are then driven at right angles to these, to leave square pillars, as shown. When this system is applied to a bed that is only 30 or 40 ft. thick, from three-fourths to eight-ninths of all the material in the deposit can be removed, the remainder being left as pillars; but where it be- comes necessary to leave floors be- tween the succeeding levels, as shown in (5), Fig. 35, scarcely one-half of the deposit can be removed, even when it is of such a firm nature that the gal- leries can be driven considerably wider than the thickness of the pil- lars. This system of mining is applied to the removal of salt, gypsum, build- ing stone, and various low-grade ores, and is very similar to the room-and- pillar system (see page 280). # ;s no timbering, and that, owing to the MINING THICK DEPOSITS. 319 Fig. 36. Fig. 37. depending principally on the cost of the stowing material compared with the value per ton of the deposit being removed. In this process, the filling * material should be composed entirely of large pieces, so that it can be packed closely. Transverse Rooming With Filling.— In other cases, a filling system is used in which rooms or chambers are driven across the deposit and then con- tinued upwards by overhand stoping, the ore being thrown to a lower level through a chute cribbed up as the work progresses, and the excavated space filled up with broken rock brought down through a chute from above, as showm in Fig. 36. After the rooms are worked out between two levels, the pillars are removed in the same manner. Longitudinal Back Stoping With Filling.— In this case, the deposit is worked as a series of overhand stopes, Fig. 37, the space below the workmen being filled with broken rock a brought down through raises b from above, the ore being thrown to a level c, which has been timbered through the filling material on larger size of the chambers, the material can be removed at a low cost per ton. The disadvantages are that a large portion of the deposit has to be left untouched, and that where the formation being mined is at all soft, it is not safe to work these large chambers. Filling Methods.— Sometimes a filling of worthless material is substituted for the worked-out ore. This system may be carried on by any one of a number of different plans. Slicing Method. — In some cases, comparatively small drifts or chambers (from 6 ft. X 6 ft. to 10 ft. X 10 ft.) are driven through the ore across the deposit, and then tightly packed with broken rock, after which other drifts or chambers are driven beside the first ones and also packed or filled. This S rocess is continued until a slice has been removed from under the entire eposit. The process is then repeated on top of the filling, taking out suc- cessive chambers and filling them, until another slice has been removed. This method has been used in the copper mines of Spain, and has also been tried at some mines in the United States with varying degrees of success, 320 MIKING MINERAL DEPOSITS. the first or lower floor of the stope. This method has been very successfully applied to some of the large iron mines of the Lake Superior region of the United States. . The tilling material used in any one of the various filling methods may be obtained at the surface, may be partially or wholly obtained from the waste rock associated with the vein material and from drifts or passages that have to be driven in barren ground, or it may be obtained by driving drifts into the hanging wall, and opening chambers there, from which the waste may be obtained. (See also Flushing of Culm, page 314.) Caving Methods.— The longwall method of mining coal is really a caving system, but where this system is applied to the mining of large masses, it becomes necessary to introduce some special features. There are two general systems in use, caving a back of ore and caving the gob or waste only. Caving a Back of Ore. — In this system, drifts or levels are run through the ore a few feet below the top of the deposit, as though the material above were to be removed by overhand stoping, but in place of breaking the material down, it is allowed to cave by gravity. When a back of ore is thick (20 ft. or more), the entire stope is sometimes allowed to cave full and then the broken ore removed by driving heavily timbered drifts through to the farther side and drawing the crushed material into the face of the drift. When the overlying worthless material appears, op- erations are continued by removing the last set in the drift and drawing the ore Horn nearer the shaft. This method is continued until practically all the broken ore has been removed. Where the back of the ore is comparatively thin (less than 20 ft.), the caving is usually accomplished at the face of the drift only, the drift being driven a short distance beyond the timbering without support. The ore above this unsupported portion will cave in and can be removed. When the waste rock and old timber from above appear, the operator retreats, removing one set of timber from the drift, caving and remov- ing the ore over it. In this manner, operations are contin- ued until all the ore over the drift or stope has been caved, when another drift or stope is driven beside the first and the ore over it caved. In this method, blasting has to be re- sorted to only in driving the drifts, from one-half to three- fourths of the ore being obtained without the use of powder. The advantages of this system are that little blasting is re- quired; practically the entire deposit is recovered; the mining cost per ton is very low. The disadvantages are that the ore is liable to become mixed with more or less dirt, which caves down with it; only one level of the Sine can be operated at a time, and the surface of the ground is allowed to cave into the openings, thus rendering it unfit for ordinary surface uses. Caving the Waste Only.— In this system, Fig. 38, drifts A and galleries B are drivin through the top of the ore body immediately under the waste rock. After one of these drifts or galleries is completed, the floor is covered with a lagging of plank or poles, and the waste material allowed to cav eon to this platform. Subsequently, other drifts are driven beside the first one, the floor covered with lagging, and the waste allowed to cave. This P r ocess is continued until a slice has been removed over the entire surface of the ore deposit when more drifts are driven lower down and another slice removed After the first slice has been removed, the broken ot waste mate- rial is supported on the lagginglaid on the floors of the first d rifts, and hence the miners have only to support this lagging m order to supigrt the waste. The caving of any individual drift crushes the ore on either side to a con- siderable extent, thus materially reducing the blasting expense. Fig. 38. IRREGULAR DEPOSITS. 321 The advantages of this system are that the entire deposit is recovered*, little blasting is required; the ore obtained is clean; the mining expense is comparatively low per ton. , „ . _ , . „ The disadvantages are that only one level of a mine can be producing at a time; the surface is allowed to cave, thus rendering it unfit for surface uses. SQUARE-SET SYSTEM. Frequently, large masses of material are encountered, which it is neces- sary to remove, and at the same time support the surrounding material. At times, it is not desirable to fill the stope while the ore is being removed, and, at the samq time, it is impossible to support the walls by single sticks or stulls. To overcome these diffi- culties, the square-set system has been evolved, which consists in the sup- porting of the walls by means of a series of square frames, from 6 to 9 ft. square, which are placed in position as fast as the ore is removed. The use of these frames reduces the length of the individual sticks, and so produces a firm structure. The timbers may be square-sawed material or round logs. If the walls are soft, the sides and top may require lagging, and if the floor is soft or composed of ore, sills will be necessary under the posts. The mining ;s carried on by overhand- stoping system, removing one block at a time and replacing it with the square set. Fig. 39 represents a stope, the walls and roof of which are supported by square sets that are lagged from the outside, sets are made from round timber. Fig. 39. In this case, the square IRREGULAR DEPOSITS. Covoting or Gophering.— Bodies of valuable material frequently occur that cannot be mined by any regular system. These are recovered by simply following the ore throughout its irregularities and removing it with the use of as little supporting timber or other material as possible. Owing to the crooked and irregular passages that occur in such mines, the work has been called coyoting , or gophering. Sometimes regular levels are driven at stated intervals, and the coyoting, or gophering carried on from them Many of the small gold and silver mines of the West, the mines of Mexico and South America, and the Missouri lead and zinc deposits are worked by this system, the object being to remove as much of the ore as possible without the use of timbering or the driving of unnecessary passages. . Probably one of the best examples of working irregular deposits is the mining practice in the Joplin zinc district, Missouri. The deposits of zinc blende are irregularly distributed through a limestone rock, and the mining is carried on in a very crude and irregular fashion. After an ore bodv has been found by drilling, a shaft 5 ft. X 5 jt. to 6 it X 9 ft. in the clear is sunk by the contractor, the price being $4 per foot for soft and $9 per foot for hard ground for the first 50 to 80 ft., the contractor doing all the work in sinking and timbering. Through the soft ground, the shaft is timbered by 4" round poles or by 2" X 4" or 2" X 6" timbers laid flatwise, skin to skin. The mines are divided into four kinds. (1) Very hard mines that require all the ore to be drilled with air drills and blasted out, and require no timbering. (2) Mines that are hard but have open crevices between the strata where a hand drill can be driven and a charge of dyna- mite lodged and exploded, throwing down a large amount of dirt and so iarring the surrounding ground that it may be easily cut down with the miner’s pick. This kind of ground needs no timber. (3) Mines that are moderately soft and where the miner can place a blast anywhere by driving 822 COSTS OF MINING ANTHRACITE, a spud, throwing down a large amount of ore. The drifts are carried 10 ft. X 12 ft. in the clear, and are cut ahead from 6 to 10 ft. before putting in the sets of timber and laggings to hold the roof. (4) Mines that are very soft and where a drift cannot be carried over 8 ft. X 10 ft. in size, where the getting of the ore is all performed by pick and shovel, and where it is neces- sary to timber close and drive spiling overhead as well as along the sides and to resort to mud -sills in the floor of the drift. When the shaft reaches the ore and the drift is extended for some dis- tance to prove the ore bodv, underhand stoping is used and 15' holes are drilled bv hand in the bottom. A charge of 50 lb. of 40* dynamite lifts a stope 10 ft. X 10 ft. The cost of 75 tons of ore, hoisting it and dumping it on the mill platform during a shift of 9 hours in the two classes of hard mines mentioned, is, according to Mr. E. Hedburg, as follows: 1 ground boss - 2 miners at §2.00 2 miners at §1.75 2 shovelers at §1.75 1 hoister 1 engineer, who also sharpens picks and drills 1 engineer Dynamite - Fuel Oil and supplies Superintendent - Total - § 2.50 4.00 3.50 3.50 1.75 2.25 1.50 6.00 2.50 2.50 3.50 $33.40 Or 44.5 cents per ton of rough ore; this includes pumping the mine. In verv soft ground, a drift 8 ft. to 10 ft. high is driven, a spiling put in the top and sides. When one level is worked out, the whole drift is then caved from the surface and allowed to settle down on the floor of timbers. The cost of mining in soft ground is about the same as in hard ore, as the saving of labor and dynamite is expended in timber and time. A typical primitive mining plant in this region, which has a shaft 150 ft. deep, with pump, hoisting engines, and boilers, and including hand jigs, screens, and tools, costs from §2,000 to §3,000; more modern plants are however now being erected, costing §8.000 to §10,000. SPECIAL METHODS. Frozen Ground.— When the material of placer deposits is frozen, as in Alaska and Siberia, it is mined by building a fire on the surface, which thaws the earth to a depth of from 1 ft. to 14 in. The embers are then scraped awav and the thawed material removed. By repeating this operation, a shaft can be sunk, and then, by building a fire against one side, a drift can be started and continued by thawing the face. 1 ft. at a time. It has been found that 1 ft. of timber piled against the face of a drift will thaw to a depth of about 1 ft. The latest practice thaws the frozen grounc by means of a steam jet instead of by fire. The openings have to be securely but not heavily, timbered. Leaching Methods.— Salt, copper, and sulphur have been mined by leaching methods. In the case of salt, a hole is drilled into the salt formation, water allowed to flow down and dissolve the salt, and is then pumped out as a con- centrated brine. For excavating upward in salt, a jet of water is made to play upon the roof of the level to be raised, and the resulting brine is carried off 'in launders. „ _ When old workings containing the sulphides of copper are left exposed to the action of air and to percolating waters, part of the copper is converted into soluble sulphate. Water pumped from such mines may be a profitable source of the metal, for bv passing it over iron bars or scrap iron the copper will be separated and deposited as cement copper in the bottom of the vessel containing the iron. . In the case of sulphur, superheated steam is forced down to melt the sulphur, which is then pumped out. LEHIGH REGION. 323 COSTS QF MINING ANTHRACITE. The following costs include only labor and supplies, and do not include, in general, improvements, royalties, taxes, and other similar fixed charges that are independent of the method of mining. LEHIGH REGION (PENNA.). The costs for the Lehigh region, though based on the results of a single company, are believed to be very fairly representative of the entire region. They are the mean costs of two collieries where about 2,000 men were employed inside and outside, and apply to the year 1897, when the con- dition at all anthracite mines was very unfavorable to economical working, as the mines were then working on very short time. The tonnage at these collieries for the year was as follows: January, 29,775.04 February, 30,872.97 March, 42,827.04 April, 38,553.08 May, 34,090.02 June, 35,761.89 July, 44,409.13 August, 37,500.97 September, 27,406.94 1 October, 56,710.04 ! Total, November, 48,177.94 [ 463,672.08. December, 37,587.02 J The following tables show the distribution of this output by sizes during the year, and the costs per ton itemized under the several headings given: Percentages of Different Sizes. Month. Lump. Broken. Egg. Stove. Chestnut. Pea. January 10.56 23.59 18.27 18.69 14.21 14.68 February 12.34 22.54 18.11 17.98 14.50 14.53 March 11.85 19.26 18.81 19.69 13.18 17.21 April 12.81 19.21 18.35 19.48 11.14 19.01 May 13.81 19.11 18.35 19.01 11.32 18.40 June 15.29 18.60 17.73 19.08 11.23 18.07 July 14.26 19.89 17.41 18.30 11.25 18.89 August 13.56 20.26 18.10 17.72 11.49 18.87 September 12.31 20.41 18.27 18.28 11.61 19.12 October 12.21 18.01 19.15 18.89 12.28 19.46 November 11.40 18.53 19.78 19.79 12.01 18.49 December 10.78 19.56 20.09 20.32 12.07 17.18 Year 12.58 19.71 18.59 18.99 12.15 17.98 Costs of Mining and Preparation. Month. Outside. Inside. Total Cost. Credits. Net Cost Labor. Supplies. Total. Labor. Supplies. Total. January... .300 .109 .409 .951 .196 1.147 1.595 .100 1.495 February.. .297 .085 .382 .909 .190 1.099 1.519 .063 1.456 March .243 .047 .290 .844 .151 .995 1.311 .088 1.223 April .242 .071 .313 .822 .137 .959 1.303 .075 1.228 May .251 .100 .351 .852 .166 1.018 1.397 .103 1.294 June .300 .079 .379 .500 .203 .703 1.576 .103 1.473 July .240 .063 .303 .487 .162 .649 1.485 .084 1.401 August .... .248 .095 .343 .709 .182 .891 1.579 .085 1.494 September .278 .096 .374 .682 .158 .840 1.588 .054 1.534 October.... .228 .093 .321 .721 .129 .850 1.580 .072 1.508 N ovember .247 .093 .340 .806 .210 1.016 1.846 .091 1.755 December. .290 .061 .351 .833 .220 1.053 1.883 .090 1.793 Year .271 .092 .363 1.109 .162 1.271 1.634 .088 1.546 324 COSTS OF MINING ANTHRACITE. Cost per Ton of Supplies Used Inside. Distribution. Jan. Feb. Mar. Apr. May. 1 Jun. JuJ. Oils .010 .011 .007 .010 .007 .009 .006 Powder .033 .030 .031 .026 .030 .032 .029 Lumber .007 .025 .011 .004 .002 .008 .007 Props Feed .040 .027 .021 .015 .022 .027 .019 .039 .018 .019 .017 .023 .022 .022 Mules killed, etc .010 .005 .014 .019 .013 .009 .015 T rails, frogs, etc. Wire ropes .005 .012 .018 .007 .016 .009 .018 .010 .025 .010 .013 General supplies , — - .019 .021 .014 .009 .018 .021 .013 Total general supplies .166 .167 .140 .109 .133 .163 .134 Pumping machinery Hoisting machinery Ventilating machinery Boilers .009 .005 .004 .012 .016 .023 .004 Mine cars Engines .021 .018 .007 .016 .017 .,017 .024 Total repairs .030 .023 .011 .028 .033 .040 .028 Total cost inside ' .196 .190 .151 .137 .166 .203 .162 Credits .100 .063 .088 .075 .103 .103 .084 Net cost inside - .096 .127 .063 .062 .063 .100 .078 Cost per Ton of Supplies Used Outside. Distribution. Jan. Feb. Mar. Apr. May. Jun. Jul= QJ]g .010 .008 .007 .006 .009 .009 .008 T.nmhpr .022 .025 .003 .016 .015 .005 .012 Feed - .008 .004 .005 .004 .005 .005 .006 Mules killed, etc T rails, frogs, etc .001 .003 .004 .005 .002 Wire ropes General supplies .020 .021 .015 .008 .040 .016 .019 Total general supplies .060 .058 .031 I .037 .073 .040 .047 Pumping machinery Hoisting machinery .001 .008 .002 .001 ! .001 .003 .008 .001 Ventilating machinery .028 .012 .008 .014 .017 .003 .008 Breaker machinery .011 Boilers .006 .005 .002 | .013 .001 .011 .005 RroalrPT .006 .008 .005 | .006 .005 .006 .002 Tracks and sidings Miscellaneous 1 .001 r Vt\tnl wnnirs .049 .027 .016 .034 .027 .039 .016 I Uttlo 1 G 1 O ----- Total cost dutside 1 .109 .085 .047 1 .071 .100 .079 .063 Net cost outside .109 .085 1 .047 ! .071 .100 .079 .063 In the two tables above and the one following, the figures were available for seven months of the year only, but an average for these months gives a fair average for the year. WYOMING REGION. 32S Itemized Cost of Outside Labor. Occupations. Jan. Feb. March. April* May. June. July. Foreman and assistants .013 .012 .007 .006 .006 .006 .003 Clerks, shipper and supply .004 .004 .003 .003 .002 .002 .002 Hoisting engineers .009 .022 .018 .021 .019 .026 .021 Pump and fan engineers .003 .003 .003 .002 .003 .003 Locomotive engineers and helpers .014 .014 .011 .009 .011 .013 .011 Firemen and ashmen .078 .071 .056 .060 .063 .069 .057 Stablemen .005 .005 .003 .003 .004 .005 .003 Watchmen .007 .006 .004 .005 .006 .006 .004 Total miscellaneous .133 .137 .105 .109 .114 .130 .101 Topmen and footmen .004 .004 .002 .003 .003 .004 .003 Top drivers and oilers .007 .007 .006 .006 .007 .008 .007 Dumpmen .002 .003 .002 .002 .002 .003 .002 Platform and docking boss .014 .013 .013 .012 .012 .012 .012 Chute bosses .006 .006 .005 .006 .005 .004 .006 SI are pickers .059 .063 .058 .053 .048 .056 .057 Car loaders .007 .007 .007 .006 .006 .008 .008 Breaker engineer .003 .003 .002 .002 .002 .001 .002 Dirt and plane engineer .007 .001 .001 .001 .001 .001 .001 Rock and dirt men .007 .009 .009 .006 .004 .005 .005 General laborers .012 .013 .009 .011 .020 .022 .012 Total breaker .128 .129 .114 .108 .110 .124 .115 Pumping machinery .001 .001 Hoisting machinery .010 .005 .005 .005 .006 .009 .005 Ventilating machinery .003 Breaker machinery .005 .004 .004 .006 .003 .002 .002 Boilers .004 .004 .001 .005 .002 Breakers .007 .009 .007 .005 .011 .019 .006 Tracks and sidings .008 .007 .007 .009 .007 .008 .007 Miscellaneous .004 .001 .002 Total repairs .039 .031 .024 .025 .027 .046 .024 Total cost outside labor .300 .297 .243 .242 .251 .300 .240 WYOMING REGION (PENNA.). The following tables of costs for the Wyoming region give mean results from a number of different collieries which are quite widely separated in location and at which the conditions of working are so different that the mean results given are thought to represent average results for the entire region. They also apply, approximately, to the Lackawanna Valley, where the general conditions are the same, although the seams are much nearer the surface than in the Wyoming region, and the amount of gas present in the coal is much less. These same figures are probably also fairly representative of the Schuylkill and Shamokin fields. The collieries for which the following figures are averages are all operated through shafts, varying in depth from 350 to 1,100 ft., and many of the mines are extremely gaseous. The number includes several entirely new and modern surface and underground plants, and the others, though not new, have been overhauled and modernized as much as possible. At these collieries 10,000 men were employed during the year 1895, for which the data are given, and during the same year the output was 1,862,144 tons, distributed during the year as follows: Month. Ton- nage. Days Worked. Month. Ton- nage. Days Worked. Month. Ton- nage. Days Worked. January. 107,952 7.94 May 179,752 12.84 September 161,213 11.52 February 98,109 7.37 June 164,062 11.92 October.... 198,161 13.90 March.... 141,991 9.95 July 145,445 10.59 November 228,433 17.15 April .... 136,375 9.69 August .. 177,241 12.96 December 123,406 8.87 326 COSTS OF MINING ANTHRACITE. Percentages of Different Sizes. Month. Lump. Steamer. Broken. Egg. Stove. Chestnut. Pea. January 8.21 .02 17.53 20.31 21.46 18.04 14.43 February 8.29 .12 17.75 20.41 20.85 17.44 I 15.14 March 6.20 .55 17.64 20.04 20.65 18.00 16.92 April 7.01 .38 16.76 20.17 20.92 18.12 16.64 May 4.79 .27 18.63 20.33 21.42 18.23 16.33 June 3.29 .21 22.43 19.72 20.21 18.57 15.57 July August September October 7.84 .42 19.42 19.54 19.46 18.58- ! 14.74 5.05 .57 19.84 20.69 18.92 18.62 16.31 4.25 .27 18.81 21.98 19.98 19.32 15.39 4.72 .01 16.77 22.00 21.27 19.88 15.35 November 2.69 .16 15.56 22.42 22.66 20.71 15.80 December 4.40 .57 14.03 22.62 21.27 21.41 15.70 Year 5.23 .29 17.96 20.95 20.80 • 19.03 15.74 Costs of Mining and Preparation per Ton. ! Months. Outside. Inside. Total Cost. Credits. Net Cost. Labor. Supplies, j Repairs. Total. Labor. Supplies. Repairs. Total. January .363 .042 .014 .419 .934 .249 .028 1.211 1.630 .120 1.510 February .376 .042 .014 .432 .047 .273 .030 1.250 1.682 .104 1.578 March .297 .031 .010 .338 .872 .182 .022 1.076 1.414 .096 1.318 April .305 .034 .023 .362 .870 .203 .020 1.093 1.455 .103 1.352 May .270 .022 .011 .303 .839 .164 .015 1.018 1.321 .101 1.220 June .290 .032 .011 .333 .874 .206 .018 1.098 1.431 .105 1.326 July .309 .046 .019 .374 .879 .266 .033 1.178 1.552 .098 1.454 August .286 .030 .017 .333 .873 .194 .026 1.093 1.426 .102 1.324 September — .284 .039 .012 .335 .890 .201 .024 1.115 1 1.450 .105 1.345 October .267 .036 .013 .316 .856 .188 .020 1.064 1.380 .100 i 1.280 November .... .262 .029 .010 j .301 .860 .214 .018 1.092 1.393 .104 1.289 December .... .344 .045 .018 ! .407 .954 .307 .028 1.289 1.696 .120 1.576 Year .297 .034 .014 | .345 .881 .214 .023 1.118 1.463 .104 1.359 Coal Production of United States. Year. Bituminous. Anthracite. Tons of 2,000 Lb. Value. Tons of 2,240 Lb. Value. 1890 1895 1897 1898 1899 111,302,322 135,118.193 147,609.985 166,592,023 193,321,987 $110,420,801 115,779,771 119,567,224 132,586,313 167,935,304 46,468,641 57.999,937 52,611,680 53,382,644 53,944,647 $66,383,772 82,019,272 79,301,954 75,414,537 88,142,130 PRICES OF COAL. The table on page 327, given by the U. S. Geological Survey ,will be of interest as showing the fluctuations in the average prices ruling in each State since 188t. Prior to that vear. the statistics were not collected with sufficient accuracy to make a statement of average prices of any practical value. These averages are obtained bv dividing the total value by the total product, except for the years 1886, 1887, and 1888, when the item of colliery consumption was not considered Average Prices per Short Ton for Coal at the Mines Since 1886. PRICES OF COAL. 327 1901. 05 CO O CO O CO rH rH 05 ©1 lO 0© rH CO CO ©!©00©©la0©>©l©©©«0© OHOHCj © © so CO ©J 05 05 t}J ©J TjH T(H©l©lO5©©rHt''-©J00©QOCO rH rH ©4 rH >—1 HHHHH H H H Hr- In ©4 rH rH rH rH rH 1.04 1.67 1.18 •0061 N-^iOWNOHCOiOGOMCJOOCOHCO t^©)©l©l">HI>Tt 00 -COC0i0«0 : T}|©t^ COC0©l>©©00©rH©O5©©J © rH ©1 rH CO rHrHrH rH rH rH rHrHrH CO rH rH rH rH ^ © <0 .81 1.51 © © 1896. ©rH©-Q0CO©T^ ^LOOi>05I^GO©©;©©©CO © rH ©4 r-i HrHn rHrHrH rHrHrH ©4 rHrH ©4 rH HO O .83 .1.50 1.02 1895. ©UOCO©CO © rH CO ©©© rH © ©3 © ©© 1H ©<0 ;C0t>O5 00 CO©rH©CO © rH©)rH rHrHrH rHrHrH rHrHrH CO rHrH ©l rH .86 1.41 1.02 1894. CO©JrH-^lO © © © © CO CO t > » !>• fr © tr © ©1 CO t" |>. ©J © © CO © rH 05 ©1 CO ©| CO <»O5©©|©3(»l^TtfrH©rH©|>.rHa5<»^O5C0'>HX>COI> ; C0 © rH ©Q rH rHrHrH rHrH©icOrHrHrH CO ©l rH ©4 rH .91 1.52 1.09 CO 05 GO rH ©rfrHTfOO © © GO © CO © tr © CO ©^ © 00 00 00 ^ rH 1> lO 05 CO CO ©| 05 CO © CO ©} GO GO ©J 05 © H 05 © GO © ©1 hJH GO CO I> CO rH ©4 rH rH rH rH rH rHrHrH t— 1 H rH CO rH©4rH ©4 rH .96 1.59 1.14 1892. r|« © ^ © ©} © rH 00 rH ©1 H ©J 05 © CO © ©|Tf©r^©^HCO©l©©GO©rr rH©JHJ©05 05 © l> CO CO 05 GO © ©} CO © 05 05 ©q 00 rH CO © GO ©J GO ©] rH rH©i^H rHrHrHrH rH rH ©5 rHrH tJ* rH ©l rH ©4 rH .99 1.57 1.16 1891. t" © © t''- © HCOHt^HCOH©CON QOCO©^©tr rH ©© CO rH © CO © rH ©1 CO © 05©!>©qc0 0500©©^©q ©05TjH05©OqrHT^GOGOCOQO© H H ©j H H HHHrH rH rH ©4 rHrHrH CO t— 1 ©1 r-i ©4 rH .99 1.46 1.13 1890. C0O5©©TjH CO © ©J rfH © ©| © as ©J © rf © CO © — 1 ^ © ©©4©t 1H© 0505GO©aC0 0500 05©Jrt< CO tr TfJ 05 GO GO rH © tr !>. |>. 00 t". rH rH ©4 rH rH V "rHrHrH " ‘ rH rH ©4 rHrHrH ‘©4 * rH ©4 rH ’©4 ’ rH .99 1.43 1.12 1889. rH©J©rH© X'- ©J © CO GO ©© rH © ©1 © COCO rH © © CO ©1 ©J © rH Tf CO © © ©<©t>-COT^©QOI>.CO'rtl t'r rj<© !>©1©©©COOO©I H rl ©4rH H rlnHH rH rH ©4 rH rH rH ©4 rH ©4 rH w 1.00 1.44 1.13 1888. ©©©©© ©1 © GO © © © © © rH © © ©CO©©©©©©©©© rH©©©{© rHTjJ 00 CO © ©J © © ©J © © ©05©©rH©rH©©rH© HHT(i©iH HhHHHH rH ©4 CO CO CO CO rH ©4 ©4 rH CO rH CO a 1.00 a 1.95 a 1.42 1887. ©GO©©© ©HfrrHtl©©©©T^© © ©00©©©©©^©©© CO©©©j© ©COOOCOTHrH05©CO© © ©GO©l©CO©©©©l©© rH rH CO ©4 rH rH rH rH —5 rH rH * rH rH CO CO rH "©4 " rH ©j ©j '©4 ‘ CO W a 1.12 a 2.01 a 1.45 1886. CO©©©© rH©©©©©©0©© © © © © © © © © © © rH © Tf © © CO © rHrH©©}©XrH©©CO© © © © © GO rH 00 rH © ©l © © rH rH CO ©< l-H HHHHHH H H CO CO rH ©4 rH rH ©4 rH ©J CO a 1.06 a 1.95 a 1.30 State or Territory. Alabama Arkansas California Colorado Georgia Idaho Illinois Indiana Indian Territory Iowa Kansas Kentucky Maryland Michigan Missouri Montana Nevada New Mexico North Carolina North Dakota Ohio Oregon Pennsylvania bituminous Tennessee Texas Utah Virginia Washington West Virginia Wyoming Total bituminous Pennsylvania anthracite.... General average a Exclusive of colliery consumption, b Includes Alaska, c Includes Nebraska. 328 COST OF COKING COAL. COST OF COKING COAL The cost for labor alone of coking coal has been given by a number of companies in the Connellsville district as 61 cents per ton of coke produced, or 40j cents per ton of coal coked, exclusive of royalties, taxes, rents, and such fixed charges. In the “American Manufacturer” for July 27, 1899, Mr. F. C. Keighley gave the following as the proportional costs of the several items of mining and coking Connellsville coal: Coke Yard. Per Cent. Coke Yard. Per Cent. Drawing 70.01 Shifting cars 1.28 Leveling 8.96 Y"ard bosses 1.12 Charging 3.48 Masons on repairs 6.12 Carters Bookkeeper and superin- 2.48 Forking Individual cars 1.60 .52 tendent, £ of total for Sundry .51 TYviTTA q nn vfi rn 2.04 1.20 Yard pumps .76 III! 1 1 tv allU J Ql vA Cleaning tracks Total - 100.08 Mine. Per Cent. Mine. Per Cent. Room coal 52.15 Machinist .49 Drivers - 8.07 Bookkeeping, £ of total for TTpudin? oorI i 11.15 mine and yard..: .49 Rope haulage 2.81 Outside labor 1 2.03 Roads 3.03 Stable boss .96 Mine bosses 1.31 Teams .65 Fire boss 1.44 Blacksmith .98 Timber 2.83 Carpenters f 1.01 .43 Lamp cleaners .82 irdpptib - Superintendence, £ of total Inside pumps .59 for mine and yard .49 Steam pumps .55 Cagers .66 Surveys .41 Runners and oilers .80 Extra men .51 Engineers 1.01 Supplies - .92 Vi rPTTIPTI 1.13 Betterments - 1.05 Dumpers 1.25 Total 100.02 The mine labor is 67.20£ of the total labor cost, and the coke-yard labor is 32.804 of the total labor cost. The cost of equipping a coke plant and opening a mine to furnish the coal in the Connellsville region is from 8500 to $1,000 per oven, dependent on the kind of opening for the mine and local considerations. 8500 per oven is a fair price for a plant when the conditions are favorable and the mine is a drift mine, and 81.000 is a fair price for a shaft mine about 300 ft. deep, under rather unfavorable conditions. Fulton gives the cost of the various types of coke ovens as follows: Not saving by-products: Beehive, 8300; Thomas, 8800; McLanahan, 8800; Belgian, 81,000; Cop pee. 81.000; Bernard, 81,000. „ Saving by-products: Simon Carves, 81.300; Semet-Solvay. $1,600; Huessner, 81,400; G. Seibel. 81.300; Otto-Hoffman. 81.600; Festner-Hoffinan, 81.500. The usual quantitv of coal required to make 1 ton of coke is 1.4 to 1.6 tons. The lo<5s in loading coke at the ovens and again unloading it at the furnaces or steel works is 24 to 34. During the winter and in wet seasons coke takes on 2d' to 3* of moisture in transit between the ovens and the furnaces. EXPLOSIVES. 329 EXPLOSIVES. The characteristics of a good blasting explosive are: (1) sufficient stability and strength; (2) difficulty of detonating by mechanical shock; (3) handy form; (4) absence of injurious effects on the user. Explosives are divided into two general classes: (1) low explosives or ^.irect-exploding materials; (2) high explosives or indirect-exploding mate- rials that require a detonator. Low Explosives.— Gunpowder or black powder is the type of this group. Its composition varies, depending on the purpose for which it is to be used, but the ingredients commonly used in its manufacture are saltpeter, sulphur, and charcoal. The following table gives the composition of blasting powder in different countries: Composition of Blasting Powder ( Guttmann ). Ingredients. Great Britain. Germany. Austria- Hungary. France. Russia. Italy. United States. Saltpeter 75 66.0 64 62 66.6 70 64 Sulphur 10 12.5 16 20 16.7 18 16 Charcoal 15 21.5 20 18 16.7 12 20 High Explosives.— These are a mixture of nitroglycerine with an absorbing dope, the composition of which is such that, in addition to thoroughly and permanently absorbing the nitroglycerine, it is itself a gas-producing com- pound. Nitroglycerine at 60° F. has a specific gravity of 1.6. It is odorless, nearly or quite colorless, has a sweetish burny taste, is poisonous even in very small quantities, and is insoluble in water. All nitroglycerine com- pounds freeze at 42° F., and explode when confined at 360° F. It takes fire at 306° F., and, if unconfined, burns harmlessly unless in large quantities, so that a part of it, before coming in contact with the air, becomes heated to the exploding *point. Thawing Dynamite. — All frozen cartridges should be thawed, as, when frozen, cartridges are very hard to explode, and even if they do explode, the results are not nearly as satisfactory as when properly thawed. When cartridges are frozen, do not expose to a direct heat, but thaw by one of the following methods: First, place the number of cartridges needed for a day’s work on shelves in a room heated by steam pipes (not live steam) or a stove. Where regular blasting is done, a small house can be built for this purpose, fitted with a small steam radiator. Exhaust steam through these pipes gives all heat necessary. Bank your house around with earth, or, preferably, fresh* manure. Second, use two water-tight kettles, one smaller than the other, put cartridges to be thawed in smaller kettle, and place it in larger kettle, filling space between the kettles with hot water at, say, 130° to 140° F., or so that it can be borne by the hand. To keep water warm, do not try to heat it in the kettle, but add fresh warm water. Cover kettles to retain heat. In thawing do not allow the temperature to get above 212° F. Third, where the number of cartridges to be thawed is small, they may be placed about the person of the blaster until ready for use, the heat of the body thawing the cartridges. Keep cartridges away from all fires— this applies to all explosives. Do not be in a hurry, but thaw slowly. Do not thaw before an open fire. Do not put cartridges in an oven, on a hot stove, against hot iron plates, or against brick casing of a boiler. Do not put cartridges in hot water, or expose them to live steam. And do not take any kind of powder, fuse, or caps near a blacksmith shop. A large number of high explosives are made that vary but little in their composition, the main difference being in the character of the dope and in the percentage of nitroglycerine. The trade name is usually determined by the percentage of nitroglycerine, thus 10/« dynamite means that the dyna- mite contains 10 Jo of nitroglycerine, etc. Safety explosives, or as they are called in England, -permitted explosives, are compounds intended for use in gaseous mines, and they are so constituted 330 EXPLOSIVES. that they will ignite without producing the extremely high temperature given by ordinary explosives. The term flameless explosives was formerly used, but it has been replaced by safety explosives , as the absence of a flame is not now necessary to a permitted explosive. Common Blasting Explosives. Atlas. A B+ B C + c D+ D E + E M 0 o a 3 p. 0> P4 A B + B C + c No. 1 XX No. 1 No. 2 SS No. 2 S No. 2 No. 2 C No. 3 No. 3B No. 4 B & £ (2 1 0 No. 1 XX No. 1 No.2SS No. 2S No. 2 Old No. 1 No. 1 A New No. 1 No. 2 Extrs No. 2 No. 2C No. 3 XXX xxxx Giant Gelatine. Hecla Powder. 9 cD £ o Ph o3 % No. 1 A No. 1 XX No. 1 No. 1 XS No. 1 No. 2 i No. IX No. 2 XX No. 2 X No. 3 C No. 1 No. 2 No. 2X No. 3 A No. 2 No. 3 No. 3 X No. 3B No. 3 No. 4 Drilling -Adapt the size and depth of the hole to the work to be accom- plished As a rule for ordinary rock blasting, the distance between the boles shouM be equa?to from one-half to the total depth of the holes, the holes set back from the face twice as far for dynamite as for common black powder sav a distance equal to the depths of the holes or slightly less, and Cd oSe-third 1 thl lenlth of the hole^ These directions are only general, and do not apply to very deep holes. de Pe^ ness of the rock, also on size of drill holes. In all cases, the experience shafts, experience shows in weak rock. All the holes in the heading or shaft should have the same “iff SSSSSS-t the free faces formed by firing the previous holes , . l"°ho!e should^ever'hS’e^ a^harge™ f S more than 12 in. of explosive placed iu it Where several holes are fired together, this rule is sometimes slight y deviated from It fs usually best to employ a length of charge between these two limits as for instance, about 10 times the diameter of the hole* Chambering orsquibbing is the blasting out of a cavity at the bottom of a drill hole to allow of a larger charge of explosive being used. . , Rniiino a drill hole is the working of clay into any cracks op^hing into a drill "lofe to p?eveit the power g of the "blast being scattered through the char C g r h.| k -The charge must fit and fill the bot^m of bore and be packed wise with . -The charge must fit and fill the bottom of bore and be pacK< a'knife, a^^^achH^S’oppe^ into^the^hole, C strike g a wooch h* len BLASTING. 331 rammer on it with sufficient force to make the powder completely fill the bottom and diameter of the bore. Where water is not present, a more per- fect loading is made by taking powder out of cartridge and dropping it in loosely, ram each 6 or 8 in. of the charge, using the paper of each cartridge as a wad, to take down any powder that may have stuck to the sides of the hole. If water is standing in the hole, do not break the paper of the car- tridges and avoid ramming more than enough to settle the charge on the bottom, using cartridges of as large diameter as will readily run into the bore. When cartridges are used, the last cartridge placed in the hole should contain an electric exploder, or cap with fuse attached. When loose powder is used, a piece of cartridge 2 or 3 in. in length, with exploder or cap attached, should be pressed firmly on top of charge. Some blasters put an exploder or cap in the first cartridge put in the hole, placing remainder of charge on top. The charge should be placed in a solid part of the material to be broken. If possible, the face should be undercut and then the overhanging material shot down. Best results are obtained when the bore holes cross the faces or layers of the material at right angles. The charges should be placed so as to disturb the sides and roof of a tunnel through material of medium hardness as little as possible. The charge at the bottom of the tunnel snould be placed from 6 to 12 in. below the permanent level. Amount of Charge. — No invariable rule can be laid down as to the diameter and length of cartridges to be used under any and all circumstances, nor the amount or grade of powder required for all kinds of work. Much depends on the good sense and judgment of the persons using the explosive. Guttmann, in his well-known handbook on blasting, says: “There is no lack of theories for tne determination of blasting charges, ‘but their application depends on empirical facts determined by practical work. I therefore advise that the calculation of charges under ordinary conditions be neg- lected, and recommend watching actual operations for some weeks, asking for explanation from the most expert miners. In this way experience will be gotten in a short time that will enable one to estimate with some precision the proper charge to use after inspecting the spot to be blasted." A good rule by which to determine the weight of black powder to use in any given hole in bituminous workings is the following: Find the distance in feet from the charge out in the line of least resistance. Multiply the fourth power of this distance by ^ the diameter of the hole in inches, and divide this product by the thickness of the seam in inches. The result will be the weight of the charge in pounds. Thus, for a 2\ rt hole in a seam of bituminous coal 6 ft. thick, where the charge is placed 4£ ft. deep from the face of the coal, or cutting, we have for the weight of charge to be used, 9 X 9 - 9 - 9 ^ - 4X2 - 5 5 71 b 2 X 2 X 2 X 2 X 6X 12 6 Tamping.— -In deep holes, water makes a good tamping, but fine sand, clay, etc. are generally used. Fill in for the first 5 or 6 in. carefully, so as not to displace cap and primer; then with a hardwood rammer pack bal- ance of material as solid as possible, ramming with the hand alone, and not using any form of hammer. Never use a metal tamping rod. Firing.— If the work is wet, or the charge used under water, use water- proof fuse, and protect the end of the fuse by applying bar soap, pitch, or tallow around the edge of the cap. Water must not be allowed to reach the powder in the fuse or the fulminate in the cap. Exploding by electricity is best under water at great depth, as the pressure of water is so great on the fuse that it is forced through and dampens it so as to prevent firing. Seam Blasting.— If a seam is found in the rock, remove the powder from the cartridges and push it into the seam and fire a cap beside it. This will open the seam so that a larger quantity of explosive can be used, and the rock broken without drilling. In blasting coal, slate, marble, granite, free- stone, or any other material that it is desirable to obtain in large blocks, cartridges of small diameter should be used in wide bore holes, the charge being rolled in several folds of paper, to prevent its touching the sides of the bore holes. The intensity of action and the crushing effect of the explosive are thus lessened. Firing by Detonation.— Nitroglycerine explosives always require detonation by a cap or exploder in order to develop their full force. Fig. 1 illustrates the method of attaching such an exploder to the end of a fuse and the pla- cing of it in the cartridge. The exploders are loaded with fulminate of mer- cury and are slipped over the end of the fuse, after which the upper end is 332 EXPLOSIVES. crimped tightly against the end of the fuse, as shown. (Miners sometimes bite the caps on to the fuse w ith their teeth. This is a very dangerous pro- ceeding and should never be allowed, as, with strong caps, one of them exploding in a man’s mouth would prove fatal.) In placing the cap or Fig. 1. Fig. 2. Fig. 3. exploder into the dynamite or giant-powder cartridge, care should be taken that only about two-thirds of the cap be embedded in the material of the cartridge, for if the fuse had to pass through a portion of the material before reaching the cap. there w ould be danger of its igniting the material, thus causing deflagration of the cartridge in place of detonation. The fumes given off by high explosives are much w^orse in the case of del cartridge. The electric exploder, Fig. 2, has wires A and B , which carry the current to the exploder. D is a cement (usually sulphur) that protects the explosive compound C (usually mercury fulminate) and the w^hole is contained m a Conner shell. A small platinum wire E is heated by the passage of a current ^ and ignites the explosive. Fig. 3 shows the method of placing a cap or an electric exploder in a cartridge of powder. When a number of holes are ex- ploded at one time, the electric exploders are connected in series, as shown in Fig. 4, for a small number of holes, and as in Fig. 5 for a larger number. The battery for furnishing the current of electricity is a magneto machine that is worked by either pulling up or by depressing a handle or rack bar, or else by turning a crank. _ . , . . Directions for Blasting by Electricity.— Drill the number of holes desired to be Fig. 4. fired at one time; depth and spacing of holes depending on character of rock size of drill holes, etc., the blaster, of course, using his judgment in this matter Load the hole in the usual manner, fitting one cartridge with a fuse ARRANGEMENT OF DRILL HOLES. 333 (electric exploder) instead of cap and fuse. The fuse head is fitted into the bottom end of the cartridge, or into the middle of one side of the cartridge, where a hole has been punched with a pencil or small sharp stick to receive it; push the powder close around the fuse head. The fuse can then be held in position by tying a string around the cartridge and the fuse wires, binding the wires to the cartridge, as shown in Fig. 3. A shows head of fuse, £ the two fuse wires, C string used to tie wires to cartridge. Avoid taking hitches in fuse wires, as by this very common practice, the insulation of the wires may be injured and the current of electricity may pass from one wire to the other, without passing through the cap, hazarding a misfire. The cartridge containing the fuse is put in on top of the charge by some blasters; by others, at bottom of the charge. The best place for it is in the center of the charge, having part of the charge above and part below it. In tamping the hole, great care must be taken not to cut the wires, or injure the cotton covering of fuse wires, or to pull the fuse out of the cartridge. Allow at least 8 in. of the fuse wire to project above the hole, to make connections. When all the holes to be fired at one time are tamped, separate the ends of the two wires in each hole, and, by the use of connecting wire, join one wire of the first hole with one of the second, the other or free wire of the second with one of the third, and so on to the last hole, leaving a free wire at each end hole. All connections of wires should be made by twisting together the bare and clean ends; it is best to have the joined parts bright. Scrape off the cotton covering at the ends of the wires to be connected, say for 2 in., then rub the wire with a small hard stone. This makes a bright fresh wire. Be sure that all connections are clean, bright, and well twisted. Do not hook or loop wires in making connections. Bare joints in wire should never be allowed to touch the ground, particularly so if the ground is wet. This can be prevented by putting dry stones under the joints. The charges having all been connected, as directed above, the free wire of the first hole should be joined to one of the leading wires, and the free wire of the last hole to the other of the two leading wires. The leading wires should be long enough to reach a point at a safe distance from the blast, say 250 ft. at least. All being ready, and not till the men are at a safe distance, connect the leading wires, one to each of the projecting screws on the front side or top of the battery, through each of which a hole is bored for the purpose, and bring the nuts down firmly on the wires. Now, to fire, take hold of the handle for the purpose, lift the rack bar (or square rod, toothed on one side) to its full length, and press it down, for the first inch of its stroke with moderate speed, but finishing the stroke with all force, bringing rack bar to the bottom of the box with a solid thud, and the blast will be made. Do not churn rack bar up and down. It 334 EXPLOSIVES. is unnecessary and harmful to the machine. One quick stroke of the rack bar is sufficient to make the blast. Never use fuses (exploders) made by different manufacturers in the same blast. Connecting wire should be of Fig. 8. Fig. 9. same size as the fuse wire; leading wire should be at least twice as large. Covering on wire should not “ strip ” or come off easily. The power of an explosive cannot be exactly calculated from the quantity and temperature of the gas resulting from its detonation, as it is impossible to determine the exact composition of gas at the moment of explosion and during the subsequent cooling period. Tables that give the relative strength Fig. 10. Fig. 11. of explosives are apt to be misleading, as so much depends on the compo- sition of the explosive, and since there are so many explosives of varying compositions that are sold under the same name. Pressures Developed by Explosives.— According to experiments conducted ARRANGEMENT OF DRILL HOLES. 335 by Sarrau, Vielle, Nonle, and Abel, the following approximate maximum pressures, in tons per square inch, developed by various explosives, have been arrived at: Mercury fulminate, 193; nitroglycerine, 86; guncotton, 71; blasting powder, 43. _ , . Values of Explosives.— Taking gunpowder (containing 61# saltpeter) as a standard, and calling its value 1, the following are the comparative values Fig. 12. Fig. 13. of the other explosives: Dynamite, containing 75# nitroglycerine, 2.2; blasting gelatine, containing 92 # nitroglycerine, 3.2; nitroglycerine, 3.3. The arrangement of aril I holes for driving and sinking should be such as to permit the easy handling of the drills and also to minimize the number of holes and the weight of explosive. Two distinct systems are m use: (1) the center cut , by which a center core or key is first removed, and after that concentric layers about this core; (2) the square cut , in which the lines of 336 MACHINE MIXING. holes are parallel to the sides of the excavation, the rock being removed in wedges instead of in concentric circles. The center-cut method is shown in Figs. 6, 7, 8, and 9, Fig. 6 showing the face of a heading, Fig. 7 an elevation or vertical section, and Figs. 8 and 9 plans. The numbers of the holes correspond in the several views. The holes are supposed to be drilled by rock drills, and they are so placed that all except the breaking-in holes have an equal line of resistance. The num- ber of holes given is supposed to take out a clean cut of the whole section abed to the extent of 3 ft. 6 in. The order of firing the holes is: (1) break- ing-in shots 1, 2, 8 , and 4 simultaneously; (2) 5, 6, 7, 8 ; (3) 9, 10, 11, 12; (4) IS, U, 15, 16; (5) 17, 18, 19, 20. The square-cut arrangement is shown in Figs. 12 (face), 10, 11 (plans), and 13 (vertical elevation). The entering wedge, Fig. 11, is best removed in two stages: First, the part egh by the shots 1, 2, 8, and 4; and second, part efh by shots 5, 6, 7, and 8. The other shots are then fired: (1) 9, 10, 11, 12: (2) 13, lit, 15, 16; (3) 17, 18, 19, 20, each volley being fired either simultaneously or consecutively. Where there is a natural parting in the heading, advan- tage is, of course, taken of this- in the location of the shots. Figs. 14 and 15 show two arrangements of drill holes used in sinking the Parker shaft at Franklin Furnace, N. J. The size of the shaft was 10 ft. X 20 ft. in the rock. At first, only 6' cuts were put in, but these were gradually increased until IF and 12' cuts were pulled. The best average obtained was 66 ft. of shaft from 6 consecutive cuts. MACHINE MINING. The number of coal-mining machines in use has increased rapidly within a very short time. In 1896 there were 1,446 in use in the United States. During 1897 there was an increase of 542, or 37.5$, while the average yearly gain from 1891 to 1896 was only about 22$. The total tonnage won by machines in 20 States in 1897 was 22,649,220 short tons, or 16.17$ of the total product of these States, and 15.3$ of the total bituminous product of the United States. A universal mining machine has not yet been brought out, and one of the principal reasons for the failure of mining machines in a number of instances has been the attempt to use a machine under condi- tions to which it was not adapted. When a mining machine is designed and built to suit the conditions under which it is to be operated, it is safe to say that there are but few mines in which they cannot be successfully utilized. They are of particular advantage where there is a long working face and where the coal is over 3 ft. in thickness. Low seams require more under- cutting for the given output than high seams. As a rule it has not been found economical to use machines in seams pitching over 12° to 15°, though pick machines have been used in mines having an inclination of 23°, the difliculty being not so much in the cutting as in moving the machine from place to place. There are four general types of mining machines in use; pick machines, chain-cutter machines, cutter-bar machines, and longwall machines. The first two are the types almost universally used in America. Cutter-bar machines have almost entirely disappeared from use excepting one type which is at present used in Iowa. Longwall mining machines have not been very generally adopted in America, as the longwall method of mining is not extensively used. Both compressed air and electricity are used for operating mining machines. Pick machines driven by compressed air are made by three separate concerns. Four companies make electric chain machines and one of these four is also making a compressed-air chain machine. One makes a longwall machine, and one has brought out a pick machine for electric power. Pick machines work very similarly to a rock drill. They can be used wherever mining machines are applicable, and their particular advantage is that they are more perfectly under the control of the operator, who can cut around pvrites and similar obstructions without cutting them with the machine. ‘ This renders such a machine particularly applicable for seams of VENTILATION OF MINES. 337 coal having rolls in the bottom and containing pyrites or other hard impuri- ties. They are also applicable for working pillars on which there is a saueeze, as they are light and can be easily handled and readily removed. q Chain-cutter machines consist of a. low metal bed frame upon which is mounted a motor that rotates a chain to which suitable cutting teeth are attached. To operate chain machines to the best advantage, the coal should be comparatively free from pyrites. They also require more room than pick machines, and a space from 12 to 15 ft. in width is nece&sa p , „ a Jo n l = t ^ e ^® to work them to advantage. These machines have proved failures m some mines on account of the incessant jarring of the roof by the re & r Jack. Chain-cutter machines cannot be used to undercut coal when a squeeze is upon it. Coal seams that are comparatively level and free from pyrites and have a comparatively good roof can undoubtedly be more satisfactorily and economically cut with chain-cutter machines than with any other type. The average height of cut is to 5 in., and at this height the chain- cutter machines makes only about 60/c as much small coal as a pick machine. This is not always an advantage, as it does not always allow sufficient height for the coal to fall down after the cut is made. In a 3£' seam, 3 men are required to handle the machine to advantage. .. , . _ . . „ Shearing —All the pick machines can be converted into shearing machines and can be used for longwall work by using a longer striking arm and a longer supply hose. The chain machines are used to do shearing work by having the cutting parts turned vertically. . . .. „ , Capacity.— The average producing capacity of each mining machine used in the United States was 11,398 tons in 1891, 11,373 tons m 1896, and 11,393 tons in 1897. So much depends on the local conditions that it is almost impossible to give specific data of rates of working and costs, but the following are fair working approximations. A good pick machine will undercut 450 sq. ft. m 10 hours, while an ordi- nary miner will undercut 120 sq. ft. in the same time. In a seam varying from 41 to 6 ft in thickness, the machine will undercut from 50 to 100 tons of coal in 10 hours. The cost of undercutting under these conditions has been giv en as approximately 10 cents per ton. Extraordinary records show 1,400 sq. it. to have been cut in 9 hours in Western Pennsylvania, and in an 8' seam, 240 tons have been undercut in a shift of 10 hours. A good chain cutter will make from 30 to 45 cuts, 44 m. wide and 6 it. deep in 10 hours under moderately fair conditions, while m high seams two men handling the same machine under ordinary conditions can make 60 cuts per shift, and under particularly favorable conditions, 80 to 120 cuts per shift. VENTILATION OF MINES. This subject is divided naturally into (a) gases occurring m workings, explosive conditions, quantity of air, distribution of air, and (o) ventilating methods and machinery. THE ATMOSPHERE. Composition.— Air consists chiefly of oxygen and nitrogen, with small and varying amounts of carbonic-acid gas, ammonia gas, and aqueous vapor. These gases are not chemically combined, but exist in a free state m umtorm proportion, as follows: ■ ■ r ,,r • * ^ By Volume. By \\ eight. 100.0 100.0 Wherever air is found, its composition is practically the same. Weight —The weight of 1 cu. ft. of air at 32° F. and under a barometric pressure of 30 in. is .080975 lb. Air decreases in weight per cubic foot as we ascend in the atmosphere, and increases as we descend below the surface of the earth. 338 VENTILATION OF MINES. The weight of 1 cu. ft. of dry air at any temperature and barometric pressure is found by means of the formula 1.3253 X B W 459 + t * in which w = weight of 1 cu. ft. of dry air; B = barometric pressure (inches of mercury); t = temperature (degrees F.). The constant 1.3253 is the weight in pounds avoirdupois of 459 cu. ft. of dry air at a temperature of 1° F. and 1 in. barometric pressure. Example.— Find the weight of 1 cu. ft. of dry air at a temperature of 60° F. and a barometric pressure of 30 in. w 1.3253 X 30 “459 + 60 = .07661b. Table of Weight of Dry Air. Weight of 1 cu. ft. of dry air at different temperatures and barometric 1 3253 X B pressures, as calculated by the formula w = + . Temperature. Degrees F. t Weight of 1 Cu. Ft. of Dry Air (Lb. Avoirdcpois). Barometer (In.). B — 27. Barometer (In.). B = 28. Barometer (In.). B = 29. Barometer (In.). B = 30. 0 .07796 .08085 .08373 .08662 5 .07718 .08002 .08285 .08569 10 .07631 .07914 .08196 .08478 15 .07550 .07830 .08109 .08388 20 .07470 .07747 .08023 .08300 25 .07393 .07667 .07041 .08215 30 .07318 .07589 .07860 .08131 32 .07288 .07558 .07828 .08098 35 .07244 .07512 .07780 .08048 40 .07171 .07435 .07701 .07967 45 .07099 .07362 .07625 .07888 50 .07031 .07291 .07551 .07811 55 .06961 .07219 .07477 .07735 60 .06895 .07150 .07405 .07660 65 .06828 .07081 .07324 .07587 70 .06766 .07016 .07266 .07516 75 .06701 .06949 .07197 .07445 80 .06648 .06884 .07130 .07376 85 .06576 .06820 .07064 .07308 90 .06519 .06760 .07001 .07242 95 .06490 .06699 .06938 .07177 100 .06401 .06638 .06875 .07112 110 .06288 .06521 .06754 .06987 120 .06180 .06409 .06638 .06867 130 .06075 .06300 .06525 .06750 140 .05974 .06195 .06416 .06637 150 .05874 .06092 .06310 .06528 160 .05781 .05995 .06209 .06423 170 . .05688 .05899 .06110 .06321 180 .05601 .05808 .06015 .06222 190 .05514 .05718 .05922 .06126 200 .05430 .05631 .05832 .06033 220 .05271 .05466 .05661 .05856 240 .05119 .05309 .05498 .05688 260 .04978 .05162 .05346 .05530 280 .04840 .05020 .05200 .05380 300 .04714 .04888 .05063 .05238 350 .04423 .04587 .04751 .04915 400 .04166 .04321 .04475 .04629 THE BAROMETER. 339 Atmospheric Pressure.— The term barometric pressure is the pressure caused bv the weight of the atmosphere above a given point. It is measured by the barometer, and this gives rise to the synonymous term barometric pressure. Atmospheric pressure is usually stated in pounds per square inch, while barometric pressure is stated in inches of mercury. Thus, at sea level, the atmospheric pressure under normal conditions of the atmosphere is 14./ lb. per sq. in., while the barometric pressure at the same level is 30 in. of mercury column, or simply 30 in. , . ' , . Barometric Variations.— The pressure of the atmosphere is not constant, but is subject to fluctuations depending on the condition of the atmosphere. Besides these, there are fluctuations that are more or less regular and are called barometric variations. There is both a yearly and a diurnal, or daily, variation. Of these two, the more important and the. more regular is the daily variation, in which the barometer attains a maximum height from 9 to 10 o’clock a. m., and a minimum about 4 o’clock p. m. Other maximum and minimum readings are obtained at 10 p. m. and 3 a. m., respectively; but these are not as pronounced as those occurring in the daytime. The daily barometric variations range from .01 to .08 in. Mercurial Barometer.— This barometer is often called the cistern barometer; or when the lower end of the tube is bent upwards instead of the mouth of the tube being submerged in a basin, it is known as the siphon barometer. The instrument is constructed by filling a glass tube 3 ft. long, and having a bore of £ in. diameter, with mercury, which is boiled to drive off the air. The thumb is now placed tightly over the open end, the tube inverted, and its mouth submerged in a basin of mercury. When the thumb is withdrawn, the mercury sinks in the tube, flowing out into the basin, until the top of the mercury column is about 30 in. above the surface of the mercury m the basin, and after a few oscillations above and below this point, comes to rest. The vacuum thus left in the tube above the mercury column is as perfect a vacuum as it is possible to form, and is called a Torricelli vacuum, after its discoverer. There being evidently no pressure in the tube above the mercury column, and as the weight of this column standing above the sur- face of the mercury in the basin is supported by the pressure of the atmos- phere, it is the exact measure of the pressure of the atmosphere on the surface of the mercury in the basin. If the experiment is performed at sea level, the height of the mercury will be found to average about 30 in., at higher elevations it is less, while if we descend deep shafts below this level, it Is greater. Roughly speaking, an allowance of 1 in. of barometric height is made for each 900 ft. of ascent or descent from sea level (see calculation of barometric elevations). A thermometer is attached to each mercurial barometer to note the temperature of the reading, as it is customary m all accurate work with this instrument to reduce each reading to an equivalent reading at 32° F., which is the standard temperature for barometric readings. A scale is provided at the top of the mercury column with its inches so marked upon it as to make due allowance for what is called the error of capacity. In other words, the inches of the scale are longer than real inches, since the level of the mercury in the basin rises as it sinks m the tube, and vice versa. The top of the mercury column is always oval, convex upwards, owing to capillary attraction, and the scale is read where it is tangent to this convex surface. , , „ ., . , Aneroid Barometer.— This is a more portable form than the mercurial barometer. It consists of a brass box resembling a steam-pressure gauge, having a similar dial and pointer, the dial, however, being graduated to read inches, corresponding to inches of mercury column, instead of reading pounds, as in a pressure gauge. Within the outer case is a delicate brass box having its upper and lower sides corrugated, which causes it to act as a bellows, moving in and out as the atmospheric pressure on it changes. The air within the box has been partially exhausted, to render it sensitive to atmospheric changes. The movement of the upper surface of the box is communicated to the pointer by a series of levers^ and the dial is graduated to correspond with the mercurial barometer. Calculation of Atmospheric Pressure.— The weight of the mercury column of the barometer is the exact measure of the pressure of the atmosphere, since it is the downward pressure of the atmosphere that supports the mercury column, area for area; that is to say, the pressure of the atmosphere on 1 sq. in. supports a column of mercury whose area is 1 sq. in., and whose height is such that the weight of the mercury column is equal to the weight of the atmospheric column. Hence, since 1 cu. in. of mercury weighs .49 lb., 340 VENTILATION OF MINES. the atmospheric pressure that supports 30 in. of mercury column is .49 X 30 = 14.7 lb. per sq. in. In like manner, the atmospheric pressure correspond- ing to any height of mercury column may be calculated. It will be observed that the sectional size of the mercury column is not important, since it is supported by the atmospheric pressure on an equal area, but the calculation of pressure is based on 1 sq. in. Water Column Corresponding to Any Mercury Column.— The density of mercury referred to water is practically 13.6; hence, the height of a water column corresponding to a given mercury column is 13.6 times the height of the mercury column. For example, at sea level, where the average barometric pressure is 30 in. of mercury, the height of water column that the atmos- pheric pressure will support is 13.6 X = 34 ft. This is the theoretical height to which it is possible to raise water by means of a suction pump, but the length of the suction pipe should not exceed 75 $ or 80$ of the theoretical water column. . , , , Calculation of Barometric Elevations.— Such elevations, although approxi- mate, are useful for many purposes. The barometric readings are reduced to equivalent readings at the standard temperature of 32° F., and for deter- mining differences in elevation, the readings of two barometers should be taken, if possible, at the same time. It must not be supposed, however, that the barometer alwavs reads the same for the same elevation at this tempera- ture. The temperature of the atmosphere has indeed very little effect on the atmospheric pressure, which is due to the weight of air above the point of observation, aerial currents, and other phenomena. In the more accurate determinations of vertical height or elevation by means of the barometer, the following formula is usually employed: R = reading of barometer (inches) at lower station; r — reading of barometer (inches) at higher station; T = temperature (F.) at lower station; t = temperature (F.) at higher station; H = difference of level in feet between the two stations. H= 56,300 (log B- log 0(l + ^)- log R H 56,300 1 + ( i +— -1 \ + 900 I + log r. More simply: H = 49,000 (§^) (l + ) . R = ’49,000 (900 + T+ t) -f 90017] .49,000 (900 + T+ t) - 900 id * Correction for Temperature.— Mercury expands about .0001 of its volume for each degree Fahrenheit. To reduce, therefore, a reading at any tem- perature to the corresponding reading at the standard temperature of 32° F., subtract of the observed height for each degree above 32°; or, if the temperature is below 32°, add TT ,^ for each degree. Thus, 30.667 in. at 62° F. is equivalent to a reading of 30.555 in. at 32° F., since 30.667 -^-^=(30.667) - 30.667 -.092 = 30.555 in. Depth of Shafts.— The barometer is often employed to determine the depth of a shaft or the depth of any point in a mine below a corresponding point on the surface. The aneroid is employed for this work, being more portable. Allowance must always be made in such cases for the venti- lating pressure of the mine. A simple formula often used for such calcu- lations is the following: • H= 55,OOo(l-^), in which the letters stand for the same factors as designated above. The most important use of the barometer in mining practice, however, is found in the warning that it gives of the decrease of atmospheric pressure, and the expansion of mine gases that always follows. CHEMISTRY OF GASES. 341 CHEMISTRY OF GASES. All matter exists in one of three forms, solid , liquid , or gaseous, according to the predominance of the attractive or the repulsive forces existing between the molecules For example, water exists as ice, or in a solid form, when the attractive force exceeds the repulsive force between its molecules As the^enmeratu^ is raised or heat is applied, the ice assumes the liquid form due to^hl more rapid vibration of the molecules of which it is composed. In other words, the repulsive force existing between the molecules is increased aid the result is a liquid. If we still further raise the tempera- S% bv applying more heat, the vibration of the molecules becomes yet more rapid, the repulsive force is increased between the molecules, and a gas or vapor called steam is formed. . . • An atom is the smallest conceivable division of matter A molecule is a collection of two or more atoms, united by affinity. The atom cannot consist of more than one element. The molecule may be either simple or compound. If compound, it is a chemical compound, itS Che^afcomp^nTs^ compound is one formed by the union of two or more atoms chemically, such atoms uniting always in fixed or definite°proportions. The properties of a chemical compound are always Mechanical Mixture. — A mechanical mixture is_ composed of different sub- stances that are not chemically united, and which are mixed in no fixed Smmrtion The properties of a mechanical mixture present a regular proportion, ine p p iTnllTn to a minimum state. Thus, a solution of gradation from a is not a chemical compound of salt and water, bTCplv a mechanical mixture of the salt in the water. If more salt is Slo t^tPr thp strength of the mixture or the brine is increased; added to the water the strengm onu«mt . g legg> Qn the other ha nd, an it -^if?s ! chemffial compound formed by the union of 1 atom of sodium withTatoin of chlorine, the two atoms being bound together by chemical Affinity, and always uniting in the same proportion, 1 atom of each, to form Sal The air that we breathe is a mechanical mixture of nitrogen and oxygen gases with small amounts of other ingredients. The nitrogen and oxygen gases’ are in a free state; that is to say, they are not combined as in a chem- fca? compound. This Is true, although the proportion of these two gases, oxvgen and nitrogen, in the atmosphere, is uniformly in the ratio of say, 1 volume of oxygen to 4 of nitrogen. Firedamp is another example of true mechanical mixture, consisting chiefly of a mixture of marsh gas CH± and Sfwith smaU amounts of other hydrocarbons and a varying amount of carbonic-acid gas, which is always present in firedamp. These gases are not combined chemically, but are mixed in varying proportions. Atomic volume, or specific volume , means simply relative volume. These terms refer to the relative volume of gases resulting from any particular reaction. By means of the laws of atomic volume, we can ascertain the volumes of the different gases resulting from any particular reaction. 1 he chemical reaction that takes place between the elements constituting the different gases is expressed by means of a chemical equation. When we have expressed such reaction by a chemical equation, we can then calculate the volumes of the gases formed, with respect to the original volumes of the gases entering into the reaction. It must be observed, how- ever, that the atomic volumes express merely the relative^ volumes of gases; or, in other words, the ratio of the volumes of gases before and after the rea LawToTvollme a — The following laws of volume refer to gases only, and ^First— EquaWoVum^of all gases, under the same conditions of tempera- ture and pressure, contain the same number of molecules. Hence, the molecules of all simple gases are of the same size. - Second.— The molecules of compound gases, under like con ditions of tem- perature and pressure, occupy twice the volume of an atom of hydrogen gas. There are very few exceptions to these two laws of gaseous volume, and the exceptions are unimportant so far as mining practice concerned. _ An element is a form of matter that is composed wholly of like atoms. Thus hvdrogen, oxygen, iron, copper, gold, and silver are elements. Chemical Symbols and Equations.— To facilitate the writing of chemical 342 VENTILATION OF MINES. equations expressing the reaction that takes place between elements under certain conditions, it is usual to express the elements by letters called symbols. These symbols stand for the elements that they represent, and are written as capital letters, except where two letters are used to express a symbol, in which case the first letter only is a capital. Thus, C is the symbol for the element carbon, but Cu is the symbol for copper (cuprum) and Co is the symbol for cobalt. It is important that these symbols be written exactly in this manner; otherwise they are liable to be frequently misconstrued. For example, Co stands for cobalt, while the symbol CO Table of Elements. Element. Symbol. Atomic Weight. Element. Symbol. Atomic Weight. Aluminum Al 27.5 Manganese Mn 55.0 Antimony (stibium) Sb 120.0 Molybdenum Mo 96.0 Argon(?) A Neodymium(?) Nd Arsenic As 75.0 Nickel Ni 58.8 Barium P'7- 137 0 Niobium . Nb 94.0 Beryllium Be 0 4 Nitrogen N 14.0 Bismuth Bi 208.0 Osmium Os 191.0 Boron B 11.0 Oxygen O 16.0 Bromine Br 80.0 Palladium Pd 106.5 Cadmium Cd 112.0 Phosphorus. P 3L0 Caesium Cs 133.0 platinum Pt 197.0 Calcium Ca 4o!o Potassium (kalium) K 39!o Carbon C 12.0 Praseodymium(?) Pr Cerium Ce 138.0 Rhodium Eh 104.0 Chlorine Cl 35.5 Rubidium Eb 85.0 Chromium Cr 52^5 Ruthenium Eu 10L0 Cobalt Co 59.0 Samarium(?) Sa Columbium Cb 93.7 Scandium Sc Copper (cuprum) Cu 63.0 Selenium Se 79.0 Didymium D 147.0 • Silicon Si 28.0 Erbium(?) Er 169.0 Silver (argentum) Ag 108.0 Fluorine F 19.0 Sodium (natrium) Na 23.0 Gallium Ga 69.0 Strontium Sr 87.5 Germanium Ge Sulphur S 32.0 Gold (aurum) Au 196.7 Tantalum Ta 182.0 Helium(?) He Tellurium Te 127.0 TTvrlrn^pn H 1.0 Thallium Tl 205.0 Xlj Tnrlinm In 113.4 Thorium Th 231.5 TodinP! I 127.0 Tin (stannum) Sn 108.0 Iridium Ir 193.0 Titanium Ti 48.0 Iron (ferrum) Fe 56.0 Tungsten (wolfram) ... W 184.0 Lanthanum La 139.0 Uranium U 240.0 Lead (plumbum) Pb 207.0 Vanadium V 51.2 Lithium Li 7.0 Ytterbium Yb Magnesium Mg 24.0 Yttrium Y 89.0 Mercury (hydrargy- Zinc Zn 65.0 rum) Hg 200.0 Zirconium Zr 90.0 stands for carbonic-oxide gas, which is a chemical compound composed ot two elements, carbon and oxygen. ...... A molecule is expressed by writing the symbols of its elementary atoms. Where more than 1 atom of a substance or element enters into the compo- sition of a molecule, the number of atoms of such element is expressed by a small subscript letter written immediately after the symbol of the element. Thus carbonic-acid gas is composed of 1 atom of carbon chemically united with’ 2 atoms of oxygen, and is expressed by the symbol C0 2 . Where the symbol is written without such subscript figure, 1 atom only is meant. Thus carbonic-oxide gas being composed of 1 atom of carbon chemically united to 1 atom of oxygen, is expressed by the symbol CO. CHEMISTRY OF GASES. 343 A large figure written before the symbols expressing the molecule indi- cates the number of molecules entering into the reaction. A large figure is sometimes used before the symbol of a single element to indicate the number of atoms of that element that enter the reaction. In any reaction occurring between atoms of matter, no matter is destroyed. In any reaction, there are always the same number of atoms after the reaction as before the reaction took place. A chemical equation is therefore an expression of equality between the atoms before and after a reaction takes place. The first member of the equation contains the substances that act upon each other while the second member of the equation contains the substances that are formed by the reaction. The number of atoms is the same in each member of the equation. „ , . , . Example.— T o express the reaction that takes place when carbonic- oxide gas burns in the air to produce carbonic-acid gas, we write CO -+• 0 -H 4 N — C0 2 -f- 4 N In this equation, each molecule of carbonic-oxide gas CO takes up 1 atom of the free oxygen of the atmosphere to form carbonic-acid gas C0 2 . The nitrogen in the atmosphere being 4 times the volume of oxygen, is expressed as 4 atoms in the equation. This nitrogen, however, remains inactive, and takes no part in the reaction. It is written on both sides of the equation for the purpose of determining the atomic volumes of the gases before and after the reaction, as explained below. The reaction for an explosion of firedamp is + 40 + 16N = 00 2 + 2 H,0 + 16 N m In this equation, each molecule of marsh gas CH* is dissociated; that is to say, its atoms are separated. The atom of carbon in the molecule unites with 2 atoms of the oxygen of the air to form carbonic-acid gas C0 2 . The 4 atoms of hydrogen, in like manner, combine with two atoms of oxygen in the air to form 2 molecules of water or steam 2 (HO), or 2 H 2 0. The nitro- gen in this equation is equal to 4 times the volume of the oxygen consumed, and is therefore written as 1 6N, since a total of 4 atoms of oxygen have been used. The nitrogen is however inert, and plays no part in the reac- tion itself, but is written here on both sides of the equation, as in the previous equation, in order to properly represent the atomic volumes of the gases or their relative volumes before and after the reaction takes place. Calculation of the Relative Volumes of Gases— To calculate the relative volumes of the gases before and after the reactions expressed in each of the equations given in the preceding paragraphs, write beneath the symbol of each molecule or atom its atomic volume. In the chemical equation expressing the reaction that takes place when carbonic-oxide gas CO burns to carbonic-acid gas C0 2 , we have as follows: CO + O + 4N = C0 2 + 4 N Atomic volumes, 2+1+4= 2+ 4 or in this reaction, 7 volumes have been reduced to 6 volumes. Such a change of volume often takes place in chemical reactions. All attempts to explain the cause of this change of volume, however, have thus far failed; but that the change of volume does take place has been demonstrated by a large number of experiments. . ' _ . . . , To calculate the volume of air consumed in the complete explosion of 100 cu. ft. of carbonic-oxide gas CO, we write the ratio of the relative volumes of carbonic-oxide gas and air, which is 2 : (1 + 4), or 2 : 5; and to obtain the actual volume of air consumed in the explosion of 100 cu. ft. of carbonic- oxide gas, we write the proportion 2 : 5 : : 100 : x, or x = — ^ — = 250 cu. ft. To find the volume of carbonic-acid gas C0 2 produced in the complete explosion of 100 cu. ft. of earbonic-oxide gas CO, write the ratio of the atomic volumes of these two gases 2 : 2, which shows no change of volume, and. therefore, the. volume of carbonic-acid gas C0 2 produced will be the same as the volume of carbonic-oxide gas CO burned. To find the volume of air consumed m the complete explosion of 100 cu. ft. of marsh gas CH h write the equation expressing the reaction that takes place in this explosion as given above, CH± + 40 + 16 N = C0 2 -f 2 H 2 0 + 1 6N Atomic volumes, 2 + 4 + 16 = 2 + 4 + 16 There is no change of volume caused by the explosion, since 22 volumes on one side of the equation produce, likewise, 22 volumes on the other side; or 22 volumes before the explosion produce 22 volumes after the explosion. 344 VENTILATION OF MINES. To find the volume of air consumed, we write the ratio of the atomic volumes of marsh gas and air 2 : (4 + 16), or 2 : 20, or 1 : 10; that is to say, roughly speaking, the amount of air consumed in the complete explo- sion of marsh gas is 10 times the volume of the marsh gas. This is not exact, however, as the volume of nitrogen in the air is 3.83 times the volume of oxygen. Making this correction, the volume of air consumed in the complete explosion of marsh gas is 9.66 times the volume of the gas. To determine the percentage of pure marsh gas in the above firedamp mixture (marsh gas and air), we write the ratio of the atomic volumes of these two, 2 : (2 + 4 + 15.32), or 1 : 10.66; and — X 100 = 9.38$ of CH±. 1 U* DO The volume of carbonic-acid gas formed in this reaction is equal to the volume of marsh gas consumed, and the volume of watery vapor is double the volume of marsh gas consumed; the total volume of gas and vapor formed by the reaction is the same as the original volume of marsh gas and air, or firedamp mixture, since the sum of the atomic volumes on each side of the equation is the same. Atomic weight is the relative weight of an atom of an element compared with an atom of hydrogen. Atomic weight is, then, not an absolute weight to be expressed in pounds, ounces, or any other denomination, but is simply relative weight. The atomic weight of each of the elements is given in the table on page 342. Molecular weight is the sum of the atomic weights of the elements forming the molecule, taking the atomic weight of each element as many times as there are atoms of that element in the molecule. A molecule of water is composed of 2 atoms of hydrogen and 1 atom of oxygen, and as the atomic weight of hydrogen is 1 and that of oxygen 16, the molecular weight of water is (2 X 1) +16 = 18. In the same manner, since a molecule of marsh gas CH4 is composed of 4 atoms of hydrogen and 1 of carbon, and the atomic weight of hydrogen is 1 and that of carbon 12, the molecular weight of marsh gas is (4 X 1) + 12 = 16. The density of a gas is the weight of any volume compared with the weight of the same volume of hydrogen or some other standard. The density of a gas is constant at all temperatures and pressures, the change of temperature and pressure affecting the gas in question and the standard alike. The density of air referred to hydrogen is 14.38. (a) The density of any simple gas, referred to hydrogen as unity, is equal to its atomic weight. ( b ) The density of any compound gas , referred to hydrogen as unity, is one-half of its molecular weight. Specific Gravity of Gases.— The specific gravity of a gas is the weight of that gas referred, to the weight of a like volume of air as a standard. It is, in other words, the ratio between the weight of like volumes of any gas and air, both the air and gas being subject to the same temperature and pressure. Thus, since the weight of 1 cu. ft. of air at a temperature of 60° F. and 30 in. barometric pressure is .0766 lb., and the weight of 1 cu. ft. of carbonic-acid gas C0 2 is .11712 lb. at the same temperature and pressure, the specific .11712 gravity of carbonic-acid gas is --y — = 1.529. Weight of Gases.— The weight of 1 cu. ft. of any gas at any given tempera- ture and pressure is found by first calculating the weight of 1 cu. ft. of dry air at the same temperature and pressure by means of the formula given on page 338 for air, and then multiplying this weight by the specific gravity of the gas referred to air as a standard. Example.— To determine the weight of 1 cu. ft. of carbonic-acid gas at a temperature of 60° F., and 30 in. barometric pressure, we multiply the weight of 1 cu. ft. of dry air, at this temperature and pressure, as found above (.0766 lb.), by the specific gravity of carbonic-acid gas (1.529). Thus, .0766 X 1.529 = .11712 lb. The table on page 349 gives the specific gravity of the gases common in mining practice, referred to air as a standard. Expansion of Air and Gases.— All air and gases expand uniformly at the same rate. The expansion and contraction of air and gases follow two simple laws that we will consider under the heads (a) Ratio of volume and absolute temperature and ( b ) Ratio of volume and absolute pressure. Absolute temperature means the temperature as reckoned from absolute zero, which is the point on the temperature scale below which it is assumed that no substance can exist in a gaseous state. * The absolute zero of the PRESSURE. 345 » Fahrenheit scale is assumed in mining practice as 459° below zero. Hence, the absolute temperature corresponding to any common temperature is found by adding 459° to the common temperature. Thus, the absolute temperature corresponding to 60° F. is 459 + 60 = 519°. Absolute Pressure.— The term absolute pressure refers to the total pressure supported by air or gas; i. e., the pressure above a vacuum. Gauge pressure is the pressure above the atmosphere. Absolute pressure is always the atmospheric pressure plus the gauge pressure. If a gauge pressure on a boiler indicates 60 lb. per sq. in., the absolute pressure supported by the steam in the boiler will be 60 + 14.7 = 74.7 lb. per sq. in. Or, if the ventila- ting pressure in a mine is equal to 13 lb. per sq. ft., the absolute pressure supported by the air in the airways will be 13 + (14.7 X 144) = 2,129.8 lb. ner so ft Relation of Volume and Absolute Temperature ( Charles ’ or Gay Lussac's law). The volume of any air or gas varies directly as its absolute temperature. Relation of Volume and Absolute Pressure ( Boyle's or Mariotte’s law).— The volume of any air or gas varies inversely as the absolute pressure it supports. For example, if we double the absolute pressure supported by air or gas, the volume of the air or gas will be reduced to one-half its original volume; if we multiply the absolute pressure 3 times, we reduce the volume to one- third the original volume; etc. „ „ . Example.— The intake current of a mine is 50,000 cu. ft. of air per minute; the ventilating pressure is 13 lb. per sq. ft. The temperature of the intake is 20° F.; the temperature of the return air is 70° F. Calculate the volume of the return air-current per minute, according to the rules of expansion of air, due to the increase of temperature and decrease of pressure, in the return current. The increased volume of the return air, due to the decrease of pressure and increase of temperature, is found by writing a compound proportion, the first member of which consists of two ratios, viz., the direct ratio of the absolute temperatures, and the inverse ratio of the absolute pressures, accord- ing to the two laws stated above. That is, we write Or, (459 + 20) : (459 + 70) 2,116.8 : 2,129.8 529 X 2,129.8 X 50,000 479X2,116.8 50,000 : x. 55,558 cu. ft. Example— In a compressed-air plant, the gauge shows a pressure of 80 lb. per sq. in. ; the area of the piston is 20 sq. in., and its stroke 10 in. The pump makes 100 strokes per minute. Assuming there is no leakage of air past the piston, what will be the volume of air discharged from the pump into the mine per minute? , „ , The volume of air discharged from the pump cylinder per minute = 20 X 10 X 100 _ 11<57 cu ft (cylinder pressure). The absolute pressure on the air in the cylinder is 80 + 14.7 = 94.7 lb. The absolute pressure on the discharged air is simply the atmospheric pressure (14.7 lb.). Hence, we write the proportion 14.7 : 94.7 : : 11.57 : x ; or, x = — ; X 11.57 = 74.54 cu. ft. per minute, nearly. , . . , In calculating the expanded volume of air or gas, it will be observed that the ratio of the original volume to the expanded volume is always equal to the product of the direct ratio of the absolute temperatures and the inverse ratio of the absolute pressures, which gives a compound proportion, the first member of which consists of two ratios, the one a direct ratio and the other an inverse ratio. r A . . - Weight Produces Pressure.— In the study of the barometer as a means of measuring atmospheric pressure, we observe that the weight of the atmos- g here produced the atmospheric pressure. In like manner, the weight of all uids produces pressure, and this pressure acts equally in all directions. This is an important consideration in the study of mine ventilation, since it has given rise to the measurement of pressure by air or motive columns. Calculation of Pressure.— An air column, or motive column, in ventilation, is a column of air having a base of 1 sq. ft., and of such height that its weight shall be equal to any given pressure. To calculate the height of air column corresponding to any given pressure, divide the pressure in pounds per square foot by the weight of 1 cu. ft. of the air. Mine pressure is also 346 VENTILATION OF MINES. measured by the water column that it will support, as in the water gauge, or by the mercury column, as in the barometer. In the measurement of pressure by means of the water column, the weight of the water column must be equal to the pressure, ( ireafor area. Since the weights of these columns are proportional to their sectional areas, it makes no difference what this area may be, the weight of the column calculated for a sectional area of 1 sq. in. will equal the pressure per square inch that supports the same. Hence, since 1 cu. in. of mercury weighs .49 lb., .49 X 30 = 14.7 lb. is the atmospheric pressure corresponding to a height of 30 in. of mercury, or, as we say, 30 in. of barometer. If we consider a cubical box, as shown in the accompanying figure, holding exactly 1 cu. ft. of water, and assume the weight of the water to be 62.5 lb., as is usual in practice, and divide the bottom of the box into 144 sq. in., as show T n in Fig. 1, we observe: (a) The pressure of the water on the bottom of the box is equal to the weight of the water, 62.5 lb.; that is to say, the pressure per square foot due to lft. of water column is 62.5 lb. ( b ) The pressure on the bottom of the box, when the water is only 1 in. deep, is equal to the weight of a layer of water 1 in. thick, or 62 5 — = 5.2 lb.; or, the pressure per square foot due to 1 in. of water column 12 is 5.2 lb. (c) The pressure per square inch on the bottom of the box is equal to the weight of a prism of water 1 ft. high, and having a base of 1 sq. in. = .434; or, the pressure per square inch due to 1 ft. of water column is .454 lb. These principles relating to the pressure of fluids are important to the student of mining, of which the following are examples: 1. In a mountainous country, several thousand feet above sea level, where the barometer registers, say, only 21 in., it is desired to know the theoretical height a pump will draw. .49 X 21 = 10.29 lb. atmospheric pressure, and = 24 ft., nearly. The theoretical suction, in this instance, is 24 ft., nearly, but the actual draft or suction would vary from f to $ of this, according to the perfection of the pump. 2. The water-gauge reading between the intake and return airways of a certain mine is 2.5 in.; to determine the pressure per square foot, we have, 2.5 X 5.2 = 13 lb. per sq. ft. 3. To determine the pressure per square foot on a mine dam, due to a vertical head of 200 ft., 62.5 X 200 = 12,500 lb. 4. To express in air column or motive column, a mine pressure equivalent to a water-gauge reading of 3 in., assuming the temperature of the air to be 60° F. and the barometric pressure 30 in., we have for the weight of 1 cu. ft. 1 3253 X 30 of air at this temperature and pressure w = — — y = .0766 lb. The pressure per square foot due to 3 in. of water gauge is 3 X 5.2 = 15.6. Then, 15 6 we have for motive column, m = = 204 ft. .0766 Diffusion and Transpiration of Gases.— Diffusion of gases means the mixing of the gaseous volumes. Graham took several glass tubes, and inserting in one end of each a plug of plaster of Paris that was porous, he filled each tube with a different gas; as for example, oxygen, hydrogen, nitrogen, etc. He then placed the open end of each inverted tube in a basin of mercury, supporting the tubes in an erect position. The gas in each tube immedi- ately began to diffuse through the porous plaster plug into the atmosphere, and it was observed that the mercury rose in each tube to take the place of the gas that passed into the atmosphere. The mercury rose in the hydrogen tube 4 times as fast as in the oxygen tube, and in the other tubes the mer- cury rose at different rates. Rate of Diffusion (Graham’s Law).— The rate of diffusion of gases into air is ~~7 % '\ m 62 S /As — jg . Fig. 1. DIFFUSION OF GASES. 347 in the inverse ratio of the square roots of their densities. The density of oxvaen being 16 and hydrogen 1, the rate of diffusion of oxygen as compared with hytogfn is 1 to 4; that is to say, the rate of diffusion of oxygen is only one-fourth that of hydrogen. Table Showing the Corresponding Mercury and Air Columns, and Pressure per Square Foot for Each Inch of Water Column. 0) bo 03 3 60 68 rH itity. d -M O fa u H U £ CC Navigation Steam. 13.21 .49 81.64 4.66 250.0 80 Dunraven Steam. 5.46 .44 84.22 9.88 218.0 70 Cyfarthfa Steam. 18.90 1.02 67.47 12.61 147.0 47 Bute Steam. 9.25 .34 86.92 3.49 375.0 120 Bonville’s Court Anthracite. 2.62 93.13 4.25 555.0 178 Watney’s Anthracite. 14.72 84.18 1.10 600.0 192 Plymouth Iron Works Bituminous. 36.42 .80 62.78 55.9 18 Cwm Clydach Bituminous. 5.44 1.05 63.76 29.75 55.1 18 Bettwys Bituminous. 22.16 6.09 2.68 69.07 1 24.0 8 Gases Enclosed in the Pores of Coal and Evolved in Vacuo at 212° F.— (If. LeChatellier.) Locality. CH 4 C0 2 N 0 Analyst. Dunraven mine (blowers) 96.70 .47 2.79 J. W. Thomas. Dunraven mine (bore hole) 96.50 .44 3.02 J. W. Thomas. Garswood mine 84.16 .86 12.30 2.65 W. Kellner. Garswood mine (blowers) 88.86 .41 8.90 1.83 W. Kellner. Glamorgan mine (blowers) 93.01 .27 5.94 .78 W. Kellner. Dombran mine (blowers) 95.11 .48 4.07 .34 f Austrian Firedamp Karwin mine 94.59 .18 4.48 .75 | Commission. Karwin mine (blowers) 99.10 .20 .70 Hruschau mine 79.16 .19 17.04 .61 Hruschau mine (blowers) 87.93 .83 10.25 .99 Peters wald mine (blowers) 90.00 .15 9.25 .60 Segen Gottes mine 83.51 1.17 15.02 .30 Sauer. Segen Gottes mine (borehole) 87.16 1.11 11.73 Sauer. Liebe Gottes mine (borehole) 77.69 3.77 18.48 .06 Sauer. Gases Enclosed in the Pores of Coal and Evolved in Vacuo at 212° F .—{Schondorfr.) Locality. Clh CiH, II C0 2 N+O Blowers. Bonifacius mine at Kray (Essen) Consolidation mine at Schalk ( Westphalia 1 Konig mine at Neunkirchen (Saarbruck) Oberkirchen mine at Schaumburg Cavities in the roof, Lothringen mine at Castrop (Westphalia) New Iserlohn mine at Lawgendren (West- phalia) 90.94 89.88 84.89 (60.46 1 93.66 27.95 ( 4.75 \ 4.00 1.62 37.64 .88 .06 1.40 5.84 2.11 1.35 .09 .30 .67 .65 2.56 .63 .45 1.34 .40 7.36 3.61 12.84 4.80 70.25 65.00 95.00 354 VENTILATION OF MINES. Fig. 2. coal seam, as illustrated in Fig. 2, and the pressure of the gas thus becomes distributed over a large area. Thus, a pressure of 10 atmospheres of a gas feeder becoming distributed over an area of 200 sq. ft. results in a total pres- sure of upwards of 2,000 tons, upon a comparatively small area of coal. As mine openings approach proximity to such a locality, this pressure man- ifests itself by bursting the coal from its position in the face, and throwing it into the entries, in some cases com- pletely blocking the openings or pas- sageways. Such an occurrence is termed an outburst. It is frequently accompanied by thunderings and poundings, which manifest themselves for several days previous to the actual outburst of gas. These poundings are _ taken as a warning by the miners S • experienced in such regions. The ' s ? poundings are probably the result of the gas working its way from one crevice to another, always advancing closer and closer to the mine openings, where they finally burst forth with extreme violence. Testing for Gas’ by Lamp Flame.— Marsh gas and firedamp are detected in mine workings by the small flame cap that envelopes and surmounts the flame of the lamp in a firedamp mixture. This flame cap is caused by the gaseous mixture, which burns as it comes in contact with the flame. The proportion of gas in the mixture determines the height of the flame cap. When testing for gas, the lamp flame is first reduced to a small, uniform size, and although this is not a universal practice, it has the advantage of giving uniform results. The lamp is held in an upright position, m one hand, while the eyes are carefully screened by the other hand from the glare of the light, the lamp being slowly raised toward the root where gas is suspected. The flame is carefully watched for the first appearance of a cap, and the height of the cap is carefully noted. Many lamps are provided with a graduated scale set opposite to the flame, so that the height of a cap may be estimated with accuracy. After the observation, the lamp is quietly and promptly withdrawn from the gas. Should flaming occur within the lamp, as sometimes happens when it is raised too quickly, or when the gaseous mixture is strong, the lamp should be withdrawn carefully and not with undue haste, as there is danger of the flame of the gases burning within the lamp being forced through the gauze by a rapid movement. This requires great presence of mind on the part of the person using the lamp. In Fig. 3 the heights of flame cap due to the presence of different proportions of marsh gas are shown. These heights, as given, refer to the experimental heights of flame cap ob- tained with pure marsh gas. It should be ob- served, however, that the presence of other gases in the firedamp will vary its explosive character, and this fact very mate- rially modifies the explo- siveness of certain caps. For example, in the ex- periments on pure marsh gas, a 2" flame cap w as found to be inexplosive; while, in the mine, and with the variable char- „ . acter of the firedamp mixtures usually found there, a flame ot 1 T % in. is often found to indicate explosive conditions. Again, flames of even less height than this often indicate dangerous conditions, especially where the coal is inflammable and there is much fine dust present m the atmosphere. These conditions account readily for the various statements that we commonly see in regard to the explosiveness of certain flames. In fact, each fire boss learns, after years of experience, to depend wholly on his 1:50 LAO 1:30 1:25 Fig. 3. 1:20 1:18 1:16 SAFETY LAMPS. 355 own knowledge, guided by tbe conditions tbat exist in tbe workings and with which he has become familiar. SAFETY LAMPS. The safety lamp is designed to give light in gaseous workings without the danger of igniting the gases present in the atmosphere. The principle of the safety lamp depends on the cooling effect that an iron-wire gauze exerts on flame. It is a well-known fact that all gases ignite at certain fixed temperatures, and if this temperature is decreased from any cause, the flame is extinguished. , „ . Use of Safety Lamps.— Safety lamps are used for two general purposes in the mine, and may be classified under two heads: (a) lamps. for general use; (b) lamps for testing for gas. , „ , . , Safety Lamps for General Work.— The essential features of a lamp designed for general mine work are: (1) safety in strong currents; (2) good illuminating power; (3) security of lock fastening; (4) freedom from flaming; (5) security against accident; (6) simplicity of construction. The conditions under which a lamp is placed at the working face differ from those that attend the testing for gas. The illuminating power of the lamp must be good, so that the workman can see clearly what he is doing. The lamp must not be too sensitive to gas, or its tendency to flame will necessitate that a care- ful watch be kept of it, and this would interfere with the prosecution of the miner’s work. Again, the miner is too often careless or neglectful of his lamp, and would fail to give it the required attention The lamp is often upset, and is apt to be broken by flying coal, or by a fall, unless carefully protected. The lamp should be so securely locked as not to permit of any tampering on the part of the miner without its being detected in the lamp room. In order that the lamp may be thoroughly and rapidly cleaned, its construction should be simple. The lamp should be easily taken apart and put together again after it is cleaned. _ . . . Lamps for Testing.— The essential features of a lamp for testing purposes are* (1) free admission of air below the flame; (2) no reflecting surface behind the flame; (3) ability to test for a thin layer of gas at the roof. When testing for gas, it is important to have a free admission of the air below and around the flame, as the flame cap is very sensitive and is inter- fered with seriously by the conflicting ascending and descending currents in a lamp in which the air enters above the flame. A more uniform cap will be given where the currents ascend quietly around the flame. # This feature is very important to the production of a good flame cap, and it is this feature that makes the Davy lamp such a favorite among fire bosses. In order that a flame cap shall be readily observed, there should be no reflection behind it, as the eye is easily deceived under these conditions. A scale by which, the height of the flame cap may be accurately measured, is a convenient feature in many lamps for testing purposes. In the use of the common Davy lamp in testing for gases, it is a common, although dangerous, practice to turn the lamp on its side and place it close up against the roof. In this position, the flame is very apt to pass through the gauze, from two causes: The gauze is readily heated, because the flame cap is close against it, and when heated, affords no protection against the passage of the flame and the ignition of the gas outside the lamp. Again, in this position, small particles from the roof are apt to fall upon the gauze, and this may often assist in the passage of the flame through the gauze. A dirty gauze is unsafe. When the lamp is turned sideways, the gauze may become smoked by contact with the flame, and this smoke, or deposit of carbon, assists greatly the passage of flame through the gauze. Another common and dangerous practice on the part of the fire boss is to brush the gas down on the lamp with his cap. By so doing, there is great danger of the flame being blown through the gauze and igniting the gas that may be present. On these accounts, it is essential that a good lamp for testing pur- poses shall be able to draw its air from a point close to the roof, in cases where it is necessary to do so. This is often accomplished by an extra tube, which is supplied with the lamp, and which may be taken off the lamp __i j. nrui ~ nrv Ck rvn t Girl A nf t.np IRTT1T) TO tllft TOT). its flame. A more uniform the lard oil commonly used in the safety lamp. 356 SAFETY LAMPS. Detection of Small Percentages of Gas.— The Davy lamp in the hands of a careful person may be made to detect the presence of gas in quantities as low as 3f*. It is claimed by some tire bosses that 2 $ of gas may be detected with a good Davy. For the detection of small quantities of gas, specially constructed lamps have been used. These lamps are designed to burn alcohol or hydrogen, giving a non-luminous flame. Among these may be mentioned the Pieler lamp, burning alcohol, which it is claimed will detect as small a quantity of gas as A device known as the Clowes gas tester has been invented, and may be attached to many safety lamps. It consists of a hydrogen tube that is designed to furnish a small stream of hydrogen to the lamp flame when testing for gas. Surrounding the wick of the lamp is a closely fitting cone, to which the hydrogen from the tube is supplied. When the lamp is to be used for testing for gas, the wick is lowered, extinguishing the oil flame after the hydrogen is turned on. It is claimed that gas may be detected in as small quantities as iJo by this apparatus attached to any good safety lamp admitting its air below the flame. The Shaw gas tester is useful for determining the percentage of marsh gas in the mine air, but it cannot be applied at the face, and samples of gas must be taken to the surface for analysis. . Oils for Safety Lamps.— Most safety lamps burn vegetable oils, which are considered the safest for mining use, and so reported by the English Mine Commission. Such oils are rape-seed oil and colza oil, made from cabbage seed. Seal oil is also largely used, and was regarded as a safe oil by the English Mine Commission. Seal oil affords a better light than vegetable oils, and in its use there is less charring of the wick. A mixture of 1 part of coal oil to 2 parts of rape or seal oil is often used, and improves the light, but the smoke from the flame is increased. The Ashworth-Hepplewhite-Gray lamp is constructed to burn coal oil, or a mixture of coal and lard oil. The Wolf lamp is especially designed for burning naphtha or benzine. Special tests have been made to prove the safety of using such a fluid in this lamp, and resulted in demonstrating the fact that the lamp was safe under any condi- tions that might arise. A thorough test was made, the oil vessel of the burning lamp being heated to 180° F., at which point the lamp was extinguished without ma nifesting any dangerous results. Types of Safety Lamps.- In the year 1815, Sir Humphrey Davy and George Stevenson, the latter a poor miner, discovered, simultaneously, that flame would not pass through small openings in a perforated iron plate. This led to the construction of what are known as the Davy, and the Stevenson or “ Geordy,” lamps. The Davy lamp is still a great favorite among fire bosses for the detection of gas in mine air. Inasmuch as all safety lamps, of which there are a large number, depend on the same principle, we will only describe such lamps as possess essential features, and which show important improvements and the gradual developments in safety -lamp construction. Davy Lamp.— Fig. 4 (a) shows a wire gauze cylinder about 5 in. in height and 1£ in. in diameter, surmounted by a gauze cap 2 in. in depth. The gauze, which has 28 wires to the inch, or 784 apertures to the square inch, is fastened to a brass standard, which secures it to the oil cup or lamp below. The gauze at the top of the lamp is doubled by the cap, which gives greater security at this point, where the flame tends to pass through the gauze more quickly, and where the gauze is more readily burned out. The mixture of gas and air enters the lamp in the lower part of the gauze, and burns within the lamp, the products of combustion passing out through the upper portion of the gauze cylinder. This lamp gives a good flame cap, on account of the free access of the air below the flame, which prevents smoking and increases the illuminating power of the lamp. As a lamp for general use, the Davy lamp, however, is unsafe, on account of its liability to flame. In many mining localities the use of this lamp is prohibited by law, except for purposes of examining for gas, when it must be used solely by properly authorized fire bosses. The flame of the lamp is also unprotected from the force of rapid air-currents, and is not safe when the velocity of the current exceeds 6 ft. per second. The illuminating power of the lamp is also not sufficient for general work. , . , , , Clanny Lamp.— The unbonneted Clanny lamp, Fig. 4 (6), is constructed according to the same principles as the Davy lamp, differing only in the fact that the lower part of the wire gauze surrounding the flame is replaced by a strong glass cylinder or chimney. The purpose of this is to increase the illuminating power of the lamp. The lamp, when clean, gives a good light, but the entrance of the air at a point above the flame, and its descent (dJ (e) Fig. 4. (f> 358 SAFETY LAMPS. within the lamp to the flame, causes the lamp to smoke, due to the conflict of the ascending and descending air-currents within the lamp. The smoke becomes deposited on the glass chimney, which interferes greatly with the light. This lamp is not a good one for gas testing, and in fact cannot be used for that purpose to any advantage. The unbonneted Clanny is not safe in an air-current having a velocity greater than 8 ft. per second. The bonneted Clanny obviates this difficulty to a large extent, but increases the tendency of the lamp to smoke. Mueseler Lamp.— This lamp, Fig. 4 (c), in all respects resembles the Clanny lamp just described, except that the tendency in the Clanny lamp to smoke is overcome in the Mueseler by increasing the draft by means of an interior wrought-iron chimney or tube, supported within the lamp, and reaching down to within an inch of the base of the flame. The air enters the lamp as in the Clanny, above the flame, but is deflected downwards by the central tube, and passes under the edge of this tube, ascending through it to the top of the lamp, where it escapes. The Mueseler lamp is a better lamp for illuminating purposes than the Clanny, and presents more security, when bonneted, against explosions within the lamp. This lamp will withstand a current of very much higher velocity than the Clanny lamp, and is reputed to be safe in a current having a velocity of 100 ft. per second. The lamp is not a good lamp for the detection of gas. It does not flame, however, as quickly as the Clanny lamp. Marsaut Lamp— This lamp, Fig. 4 (d), is built after the Clanny lamp in every respect, but is supplied with multiple-gauze chimneys, one within the other, the effect of which is to increase the security against explosion of gas within the lamp. The bonneted Marsaut lamp is a peculiarly strong lamp in this respect. The gauze used in the caps of this lamp has 984 apertures to the square inch. This lamp is often extinguished in an explosive mixture by the force of the explosion within itself. It gives a good light and is a good lamp for general work; it is not, however, a good lamp for testing for gas. Ashworth-Hepplewhite-Gray Lamp.— This lamp, Fig. 4 (e), combines a number of characteristic features. It is designed for general work, as well as for testing for gas. It often happens that gas accumulates in a thin layer along the roof of an entry or working place, and is not detected by the use of the Davy lamp or any ordinary lamp. The Gray lamp is so arranged that it can be made to draw its air from the top of the lamp, by means of openings in the top of the four standards of the lamp, the air passing down through the standards, and into the lamp, below the flame. When not in use for testing, openings can be made in the lower part of the stand- ards by moving a slide, and air enters at these openings. The lamp is essen- tially a bonneted Clanny. The glass chimney, however, as well as the gauze that surmounts it, is made in a conical form, the purpose of this being to diffuse the light upward for examination of the roof of the mine. The conical form given to the gauze also strengthens the lamp against explo- sions of gas within. This lamp is a very good all-around lamp, and possesses good illuminating power. . , . . Wolf Lamp.— The Wolf lamp, Fig. 4 (/), is rapidly growing m popularity having been already introduced in a large number of mines in America ana England, and on the Continent. This lamp is essentially a Clanny lamp with a free admission of air. It is compact and efficient, and has good illuminating power, and is also constructed in different forms, combining, as desired, any or all of the features of previous lamps. Two of its charac- teristic features, however, consist in a self-lighting arrangement accom- plished by means of a percussive device, which ignites a wax taper within the lamp, and a locking device, which can be opened only with a powerful magnet. This relighting device is an important feature in any safety lamp for general use, inasmuch as the most dangerous conditions exist immedi- ately after an explosion, and the miners are always left to grope their way in the dark. A large number of lives are lost, owing to the confusion that ensues, the men becoming bewildered and losing their wav, when they are shortly overcome by the afterdamp of the explosion. This lamp permits of immediate relighting with safety to the men. „ , _ . , _ Locking Lamps.— The ordinary lock consists of a lead plug, which, when inserted in the lamp, will show the least tampering on the part of the miner. Other locks consist of an ordinary turnbolt operated by a peculiar key. Magnetic locks allow of the opening of the lamp only by means of a Strong magnet kept in the lamp room. Cleaning Safety Lamps.— Safety lamps should be thoroughly and regularly CARE OF SAFETY LAMPS. 359 cleaned and filled between each shift. Each lamp should then be lighted and inspected by a competent person before being given to the miner. A careful inspection of the gauze of the lamp is necessary, as well as of all the joints by which air may enter the lamp. It should be known to a certainty that each lamp is securely locked before leaving the lamp room. Relighting Stations.— These stations are located at certain places in gaseous mines where they can be supplied with a current of fresh air, and where there is no danger from the gases of the mine. The lamp is apt to be overturned, or to fall, and is often extinguished thereby; and if these stations were not provided, the man would have to return with his lamp to the surface in order to have it relighted. Such a station is always located at the entrance of the gaseous portion of a mine, in cases where the entire mine does not liberate gas. Illuminating Power of Safety Lamps.— The following table gives the illumi- nating power or candlepower of some of the principal lamps. The light of a sperm candle is taken as 1, or unity. f Name of Lamp. Illuminating Power of Lamp. Davy Geordy Clanny •. Mueseler Evan Thomas. Marsaut, 3 gauzes Marsaut, 2 gauzes Marsaut, with Ho wat’s deflector Ashworth-Hepplewhite-Gray Wolf .16 .10 .20 .35 .45 .45 .55 .65 .65 .90 EXPLOSIVE CONDITIONS IN MINES. In the ventilation of gaseous seams, the air-current may be rendered explosive by the sudden occurrence of any one of a number of circum- stances that cannot be anticipated. Among these are the following: (1) Derangement of the ventilating current. (2) Sudden increase of gas due to outburts, falls of roof, feeders, fall of barometric pressure, etc. (3) Presence of coal dust thrown into suspension in the air, in the ordinary working of the mine, or by the force of blasting at the working face, or by a blown-out, or windy, shot. (4) Pressure due to a heavy blast, or any concussion of the air caused by closing of doors, etc. (5) Rapid succession of shots in close workings. (6) Accidental discharges of an explosive in a dirty atmosphere. Any or all of these causes may precipitate an explosion at any moment. Hence, the condition of the air-current should be maintained far within the explosive limit. The explosive conditions vary considerably in different coal seams. The nature of the coal and its enclosing strata, its friability and inflammability, together with the character of its occluded gases, deter- mine, to a large extent, the explosive conditions in the seam. Experience in any particular seam or district must always be the best guide, and furnish the best standard for determining the explosiveness of any given lamp flame. For example, a 2" flame may be comparatively safe in a small mine where the coal is hard and not particularly flammable, while a li" flame cap would be considered unsafe in mines where the conditions are more favorable to the generation of gas and formation of coal dust. The daily output of the mine and the general care that is enforced upon the miners at the working face are factors that should always be considered and taken into serious account in determining explosive conditions (see Testing for Gas by Lamp Flame). Derangement of Ventilating Current.— The flow of the air-current must be uniform and continuous. Doors must be kept closed, since the mere setting open of a door, for a short period of time, is sufficient to precipitate a serious explosion. Any contemplated change in the current, by the erection of brattices, air bridges, stoppings, etc., should be carefully considered before the work is begun, and every precaution adopted to secure the safety of the 360 VENTILATION OF MINES. men. Derangement of the current may occur through a fall of roof upon the main airway, by which the area of the airway is reduced, which results in the reduction of the quantity of air passing in the mine. If this fall is not noticed at once, serious results may happen. The utmost vigilance is therefore required on the part of fire bosses and all connected with mine workings. The failure of the ventilating apparatus is another source that gives rise to the derangement of the current. As a rule, furnaces are not now employed for the ventilation of gaseous seams. There are, however, some furnaces in use in such seams, and these require constant attention lest the fire should burn low. Upon any accident occurring to the ventila- ting machinery, notice should at once be given to the inside foreman, and the men withdrawn as rapidly as possible. A sudden increase of gas may occur at any time in a gaseous seam, owing to an outburst, which suddenly yields a large volume of gas and may render the mine air in that section extremely explosive. The men working on the return of such a current must be hastily withdrawn, and all lights extinguished. A heavy fall of coal in the mine workings or in the airways, or the tapping of a large gas feeder, produces the same effect in a less degree. The nearer the fall of roof takes place to the face of the workings, the more liable it is to be followed with a large flow of gas, inasmuch as the gas near the face has not had time to drain off, as in the case of old workings. This fact is always true in reference to new workings in a gaseous seam. The gas continues to flow freely for a considerable period, w r hen its flow gradually decreases until it about ceases. When a large feeder has been tapped, it may be plugged for a time, if necessary, but the better practice is to allow it to flow freely and diffuse into the air-current, which should be sufficiently increased to dilute the quantity of gas given off and to render it inexplosive. The men upon the return air should be notified. It is dangerous practice to light these feeders. When there is a large area of abandoned workings m the mine, any considerable fall of barometric pressure is usually followed by a large outflow of gas from the gobs or waste places of the mine. A fall of 1 in. m 5 hours represents a very rapid decrease of barometric pressure. At all large collieries there is, or should be, a good standard barometer located upon the surface near the shaft. In many cases, these barometers are self-recording, and are often provided with an automatic alarm that gives warning when- ever a fall of barometric pressure occurs. This warning should at once be conveyed to the men in the workings, and every precaution adopted to avoid evil results. The fact is fairly well established that a fall of atmos- pheric pressure is not followed by an outflow of gas from the mine workings for the space of, say, 3 hours after such fall occurs. This statement must be regarded with caution, however, as it largely depends on the condition and extent of the abandoned workings. Where these are full of gas, its expan- sion affects the condition of the airways much more quickly than m cases where these working places are partly ventilated. Effect of Coal Dust in Mine Workings —According to the greater or less flam- mability of the coal, the presence of fine dust in the airways and workings of the mine becomes a dangerous factor. Certain coals are extremely friable and are reduced readily to fine dust, which is thrown into suspension m the air-current by the ordinary operations of the miners in their work, as well as by the concussion of the air from numerous causes, and by the movement of cars and the traveling of men and animals upon the various haul- ways and passageways. For a long time it was questioned whether the presence of dust was a dangerous factor, except where there was also a small percentage of gas in the air. Evidence, however, has well established the fact that coal dust of itself is a dangerous element, and may often be the sole cause of an explosion, when acted upon by a flame of sufficient intensity and magnitude. The action of the flame is to distil carbonic-oxide gas (70 from the fine particles of dust suspended in the air. The explosion of the § as thus formed causes a further disturbance and raises a larger supply oi ust, which likewise contributes to the liberation of fresh quantities of gas, and thus an explosion is generated and transmitted. Small quantities of marsh gas greatly increase the violence of this action, but explosions in flouring mills and w 7 ell-ventilated coal bins establish the fact that such occurrences are not dependent on the presence of marsh gas. .... Too much faith must not be placed in the use of water by sprinkling lor laying the dust. This has a beneficial effect in the immediate vicinity, but a large amount of water is required to render an untidy working place safe MINE EXPLOSIONS. 361 at firing time. Better practice is to allow no accumulations of dust at the face. This should be regularly loaded out with the coal. Pressure as Affecting Explosive Conditions.— Gaseous mixtures that are not explosive in the ordinary condition of a mine, often become explosive under the momentary pressure to which they are subjected by heavy blasting, and, in some instances, this may occur from the concussion of the air caused by the quick shutting of a door. In the latter case, how- ever, the explosive condition of the air would necessarily have to be close to the limit, in order for such a slight occurrence to precipitate an explosion. The factor of pressure as increasing the explosiveness of gaseous mixtures should be considered and constantly borne in mind. Rapid Succession of Shots in Close Workings.— It constantly happens that two, three, or more shots are fired by means of fuse or touch squibs in a single chamber or heading, where the circulation of air is not always the best. The practical effect is that a considerable quantity of carbonic-oxide gas CO is produced by the firing of the first shot, and this gas does not have time to diffuse or become diluted by the air-current before it is fired by the flame of the following shots. An explosion may often be precipitated by such an occurrence, if the workings are at all dusty. Two shots at the most are all that should be fired at one time in a close chamber or heading. Mine Explosions.— The explosion of gas in a mine usually arises from the ignition of an explosive mixture of gas and air called firedamp , which has accumulated in some unused chamber or cavity of the roof, or in the waste places of the mine, and has been ignited by a naked light, by the flame of a shot, or by a mine fire. The initial force of an explosion is generally expended locally, but the flame continues to feed upon the carbonic-oxide gas generated by the incomplete combustion of the firedamp mixture, and distilled also from the coal dust thrown into the air by the agitation. Air is required to burn this carbonic-oxide gas; this causes the flame to travel against the air-current, or in the direction in which fresh air is found. In the other direction, or behind the explosion, the flame is soon extin- guished in its own trail when the initial force of the explosion is expended. The explosion continues to travel along the airways against the current as long as there is sufficient gas or coal dust for it to feed upon, or until its temperature is cooled below the point of ignition, by some cause such as, for example, the rapid expansion of the area of the workings. We observe the chief factor in transmitting an explosion is the presence of carbonic-oxide gas, which lengthens the flame and extends the effect. The recoil of an explosion is the return of the flame along the path that it has just traversed. In the recoil, the flame burns more quietly, advances more slowly, and travels close to the ropf. The evidence found at the point where a recoil took place, or an explosion turned back, has been sufficient to establish the fact that the recoil is caused primarily by a cooling of the tem- perature, probably caused very largely by an expansion of the area of the airway. Soot is often deposited at this point in considerable quantity, if the action of the flame is not such as to consume it. This fact alone shows the combustion at this point to have been incomplete. Immediately in the rear of the flame is a mixture of carbonic-oxide gas CO, which bursts into flame at the sudden stoppage of the advancing explosion. This is rendered possible by the flow of cold air from the adjacent chambers and workings along the floor of the airway. The flame now retreats, burning the trail of carbonic-oxide gas along the roof, fed by the cold air along the floor. To Explore Workings After a Serious Explosion.— The shafts or slopes and the ventilating machinery should claim the first attention of those on the surface, and an effort should be made to reach the bottom as expeditiously as possible. Assistance from neighboring collieries, both in the way of skilled labor and advice, should also be requested. Should the shaft or slope need repairs before communication between top and bottom is restored, the person in charge on the surface should, in the meantime, see that props of the lengths in ordinary use, brattice boards, brattice cloth, and nails are brought to a convenient place for putting on the cage or car, and he ought also to collect all the tools likely to be required, such as axes, saws, ham- mers, etc. It is also important that rough tracings of the workings be prepared for the use of the leader of each squad of explorers. Officials will understand how useful these will be to those that are penetrating into work- ings about which every man of his squad may have been heretofore ignorant. When the explorers have arrived at the bottom and are ready to proceed, there should be for each section, if more than one is operated upon, two 362 VENTILATION OF MINES. managers, each, having his own squad of men, and his own particular duty to do. One may take charge of restoring the ventilation, the inspection of the workings, and the clearing of the roads; the other may appoint and have charge of the bottom man, the conveying of material, and the detailing of stretcher companies where required. They can consult and help each other in every difficulty, but system is necessary if the work is to be done in the shortest possible time. . A . _ ... The manager who has charge of the men m front should appoint two experienced men with good nerves to act as foremen, instructing them to inspect and report to him the condition of the workings within a short radius. He should then form the rest of his men into, say, three squads of three each, who will work together at stoppings or falls until separated by him or until the end of the shift. Being near the bottom, it will probably be found that all is clear for three or four breast or stoop lengths, and stop- pings are required to be put up. Material will be required for this, and when the cage is first sent to the top for it, it should not be kept there to enable the top man to put on a big load, but it should be sent down with all despatch, loaded with a half dozen each of props and brattice boards, with one piece of cloth and nails. This will allow a start to be made, and will prevent the anxious men from worrying over what to them is an unac- countable delay. Larger loads can be sent down in subsequent trips. For convenience in carrying, the brattice cloth may be cut in lengths to suit the gangways or headings with 2 or 3 ft. to spare. Squad No. 1 should be detailed to the first stopping. This may be put up with boards at top and bottom and cloth between. If the air-current is strong, a few of the follow- ing stoppings may be put up by squads No. 2 and No 3, with cloth only stretched between two props. These can be very rapidly put up and will drive the ventilation forwards, thus allowing the firemen to extend rapidly the area of inspection. These stoppings can be completed by No. 1 detail. In a short time it may become impossible to proceed in this manner, lhe foul air will in all probability become more difficult to dislodge, and eventu- ally one detail may be able to put up stoppings as quickly as the firedamp or chokedamp can be carried off. Part of what may be called the ventilaung detail can now be transferred to the bearer detail, the duties of the latter having become heavier as the stoppings advanced. It is not an easy task to carry props long distances in a stooping posture, and when to that is added, it may be, the carrying out of the living or dead bodies, the men begin to fag very soon. But the person in charge here must see that the forward party is kept in material for stoppings so that no delay may occur on that account. A system of staging gives relief to the carrying parties. To conclude with a few general remarks Let those that nave never yet assisted to explore a mine after an explosion be assured of this, that the chief requisites in a leader are a capacity for hard work and the ability to organize his men into a system, however roughly, whereby work will be best forwarded. It mil not speed the work to say to a dozen or more men, generally, do this or that, neither is it beneficial to allow all the workmen to discuss matters and suggest plans. Those in charge ought to arrange what is to be done. Anything else results in noise and confusion. And let men that are sent from other collieries take with them their own toefis and lamps. Those in charge ought to take note of the position, etc. of bodies found, and of every point which is likely to throw light on the cause or origin of the explosion. This can be more correctly done before the roads are disturbed by oust and travel. These notes might not only be the means of ascertain- ing the cause of explosion, but also of pointing out a way of prevention m In no case after an explosion should the air-current of the mine be reversed from its usual course, except only after careful consideration, because of the reliance placed by the entombed workmen on their knowl- edge of the direction in which the air should be moving- and the reversal of the current may drive the gases of the explosion upon them with disas- trous results. Conditions must be allowed to remain as they exist, and the rescuers conform themselves to such conditions in the best manner possible. QUANTITY OF AIR REQUIRED FOR VENTILATION. The quantity of air required for the adequate ventilation of a mine can- not be stated as a rule applicable in every case. Regulations tlmt would supply a proper amount of air for the ventilation of a tlnck seam would be ELEMENTS IN VENTILATION. 363 found to cause great inconvenience if applied without modification to the workings in a thin seam. Likewise, the ventilation of an old mine with extended workings, a large area of which has been abandoned, and m many cases not properly sealed off, will require, naturally, a larger quantity of air per capita than a newly opened mine or shaft. The natural conditions existing in rise and dip workings, with respect to the gases that may be liberated or generated in those workings, call for the modification of the quantity of air required in each case. For example, dip workings, where much blackdamp is generated, will require a larger quantity of air, or higher velocity at the working face, to carry off such damps; and rise work- ings, liberating a large amount of marsh gas, will likewise require a higher velocity at the working face. On the other hand, a reversal of these conditions, such as a large quantity of marsh gas being liberated m dip workings, or a similar amount of blackdamp being generated in rise work- ings, will require a comparatively low velocity of the air at each respective Quantity Required by State Laws.— The quantity of air required by the laws of the several States is generally specified as 100 cu ft. per man per minute, and in many cases an additional amount of 500 cu. it. per animal per minute is stated. This quantity is m no case stated as the actual amount of air required for the use of each man or animal, but is only the result of experience, as showing the quantity of air required for the proper ventilation of the average mine, based on the number of men and animals employed. The number of men employed m a mine is an indica- tion of the extent of the working face, while the number of animals employed is an indication likewise of the extent of the haulage roads, or the development of the mine. These amounts refer particularly to non-gaseous Sea The Bituminous Mine Law of Pennsylvania specifies that there shall be not less than 100 cu. ft. per minute per person m any mine, while 150 cu. it. are required in a mine where firedamp has been detected. . > The Anthracite Mine Law of Pennsylvania specifies a minimum quantity of 200 cu. ft. per minute per person. Each of these laws contains modifying clauses, which specify that the amount of air in circulation shall be sufficient to “dilute, render harmless, and sweep away” smoke and noxious or da Quantity of Air Required for Dilution of Mine G.*...-To determiiie > this requires a knowledge of the quantity of gas generated °^ llb ^ted m the workings. The quantity of air for dilution should be ample, and should be such as not to permit the condition of the current to approach the explosive point. The ventilation should be ample at the face. - r . Quantity of Air Required to Produce the Necessary Velocity of Current at the Face — This consideration modifies considerably the quantity of air required for the ventilation of thick and thin seams. The velocity of the current is dependent not only on the quantity of air in circulation, but on the area of the air passage. This area is quite small in thin seams, and often very large in thick seams. As a result, the velocity is often low at the face of thick seams, and insufficient for the proper ventilation of the face, although the quantity of air passing into such a mine may be very large. A certain velocity of the current is always required in order to sweep away the gases. This velocity depends on the character of the gases and the position ot the workings. Heavy damps are hard to move from dip workings where they have accumulated; and, likewise, lighter damps accumulating ’at 'the: face of steep pitches are hard to brush away, and the velocity of the current in these cases must be equal to the task of driving out these gases. ELEMENTS IN VENTILATION. The elements in any circulation of air are (a) horsepower or power applied; (5) resistance of the airways, or mine resistance, which gives rise to the total pressure in the airway; (c) velocity generated by the power applied against the mine resistance. ,. , . Horsepower or Power of the Cur rent. -The power applied is often ^spoken of as the power upon the air. It is the effective power of the ventilating motor, whatever this may be, including all the ventilating , ^£ e J^cies, whether natural or otherwise. The power upon the air may be the power exerted by a motive column due to natural causes, or to a furnace, or may 364 VENTILATION OF MINES. be the power of a mechanical motor. The power upon the air is always measured in foot-pounds per minute, which expresses the units of work accomplished in the circulation. Mine Resistance.— The resistance offered by a mine to the passage of an air-current, or the mine resistance, is due to the friction of the air rubbing along the sides, top, and bottom of the air passages. This friction causes the total ventilating pressure in the airway, and is equal to it. Calling the resistance E, the unit of ventilating pressure (pressure per square foot) p, and the sectional area of the airway a, we have, E = pa; that is to say, the total pressure is equal to the mine resistance. Velocity of the Air-Current.— Whenever a given power is applied against a given resistance, a certain velocity results. For example, if the power u (foot-pounds per minute) is applied against the resistance pa, a velocity v (feet per minute) is the result; and since the total pressure pa moves at the velocity v, the work performed each minute by the power applied is the product of the total pressure by the space through which it moves per minute, or the velocity. Thus, u = (pa) v. Relation of Power, Pressure, and Velocity.— The relation of these elements of ventilation is not a simple relation. For example, a given power applied to move air through an airway establishes a certain resistance and velocity in the airway. The resistance of the airway is not an independent factor; that is to say, it does not exist as a factor of the airway independent of the velocity, but bears a certain relation to the velocity. Power always produces resistance and velocity, and these two factors always sustain a fixed relation. This relation is expressed as follows: The total pressure or resistance varies as the square of the velocity; i. e., if the power is sufficient to double the velocity, the pressure will be increased 4 times; if the power is sufficient to multiplv the velocity B times, the pressure will be increased 9 times. Thus, we observe that a change o*f power applied to any airway means both a change of pressure and a change of velocity. Again, since the power is expressed by the equation u = (pa) v, and since p a, or the total pressure, varies as v 2 , the work varies as vK From this it follows that, if the velocity is multiplied by 2, and, consequently, the total pressure by 4, the work performed (pa) v will be multiplied by 2 3 = 8. We thus learn that the power applied varies as the cube of the velocity. MEASUREMENT OF VENTILATING CURRENTS. The measurement and calculation of any circulation in a mine airway includes the measurement of (a) the velocity of the air-current, (b) of pres- sure, (c) of temperature, (d) calculation of pressure, quantity, and horse- power of the circulation. These measurements should be made at a point in the airway where the airway has a uniform section for some distance, and not far from the foot of the downcast shaft or the fan drift. Measurement of Velocity.— For the purpose of mine inspection, the velocity of the air-current should be measured at the foot of the downcast, at the mouth of each split of the air-current, and at each inside breakthrough, in each split. These measurements are necessary in order to show that all the air designed for each split passes around the face of the workings. The measurement of the velocity of a current is best made by means of the anemometer. This instrument consists of a vane placed in a circular frame and having its blades so inclined to the direction of its motion that 1 ft. of lineal velocity in the passing air-current will produce 1 revolution of the vane. These revolutions are recorded by means of several pointers, each having a separate dial upon the face of the instrument, the motion being communicated by a series of gear-wheels arranged decimally to each other. Most anemometers are provided with a large central pointer that makes 1 revolution for each 100 revolutions of the vane. The dial for this pointer is marked by 100 divisions, which record the number of lineal feet of velocity. In very accurate work with the anemometer, certain constants are used as suggested by the instrument maker, but these constants are of little value in ordinary practice and are of doubtful' value even in more accurate observations. The measurement of the velocity of an air-current must necessarily represent only approximately the true velocity in the airway. The air travels with a greater velocity in the center of the airway, and is retarded at MEASUREMENT OF PRESSURE. 385 the sides, top, and bottom by the friction of these surfaces. Hence, the air to a large extent rolls upon these surfaces, which naturally generates an eddy at the sides of airways. When measuring the air, the anemometer should be held in a position exactly perpendicular to the direction of the current, and moved to occupy different positions in the airway, being held an equal time in each position, or it may be moved continuously around the margin of the airway, and through the central portion. The person taking the observation should observe the caution of not obstruct- ing the area of the airway by his body, as the area is thereby reduced, and the velocity of the current increased. The area of the airway is accurately measured at the point where the observations are taken. To obtain the quantity of air passing (cubic feet per minute), multiply the area of the airway, at the point where the velocity is measured, by the velocity. Example.— The anemometer gives a reading of 1,320 ft. in 2 minutes, the height of the airway is 6 ft. 6 in., and its average width 8 ft. 8 in. What volume of air is passing in the airway per minute? 1 320 X 8f X — 37,180 cu. ft. per min. The measurement of the ventilating pressure is made by means of a water column in the form of a water gauge. Water Gauge.— The water gauge is simply a glass U tube open at both ends. Water is placed in the bent portion of the tube, and stands at the same height in both arms of the tube when each end of the tube is subjected to the same pressure. If, however, one end of the tube is subjected to a greater pressure than the other end, the water will be forced down in that arm of the tube, and will rise a corre- sponding height in the other arm, the differ- ence of level in the two arms of the tube repre- senting the water col- umn balanced by the excess of pressure to which the water in the first .arm is subjected. An adjustable scale graduated in inches measures the height of the water column. The zero of the scale is ad- justed to the lower water level, and the Fig. 6. upper water level will then give the reading of the water gauge. One end of the glass tube is drawn to a narrow opening to exclude dust, while the other end is bent to a right angle, and passing back through the standard to which the tube is attached, is cemented into the brass tube that passes through a hole in- the partition or brattice, when the water gauge is in use. The bend of the tube is contracted to reduce the tendency to oscillation in the height of water column. (See Fig. 5.) When in use, the water gauge must be in a perpendicular position. It is placed upon a brattice occupying a position between two airways, as shown at A, Fig. 6. The brass tube forming one end of the water gauge is inserted m a cork, and passes through a hole bored in the brattice. The water gauge must not be subjected to the direct force of the air-current, as m this case the true pressure will not be given. Fig. 6 shows the instrument as occupying a position in the breakthrough, between two entries. It will be observed that the water gauge records a difference of pressure, each end of the water gauge being subject to atmospheric pressure, but one end in addition being subject to the ventilating pressure, which is the difference of Fig. 5. 366 VENTILATION OF MINES, pressure between the two entries. The water gauge thus enables us to measure the resistance of the mine inbye from its position between tw o airways. If placed in the first breakthrough, at the foot of the shaft, it measures the entire resistance of the mine, but if placed at the mouth ot a split it measures only the resistance of that split. It never measures the resistance outbye from its position in the mine, but always inbye (see Calcula- tion of Pressure). ,« , . Measurement of Temperature.— It is important to measure the temperature of the air-current at the point where the velocity is measured, as the tem- perature is an important factor of the volume of air passing (see Expan- sion of Air and Gases, etc.). , __ . . _ Thermometers.— Thermometers measure changes m the temperature ot the atmosphere bv the contraction and expansion of mercury or spirits; or they may be made entirely of metal, and the changes of temperature are then measured by the expansion and contraction of the sensitive metallic portion These latter are known as aneroid thermometers. The Fahren- heit thermometer is the one most commonly used in America. By this scale, the freezing point of water at the sea level is placed at 32° above zero; the boiling point of water at sea level is placed at 212° above zero, so that the space between these two points is divided into 180°. ^ . Reaumur and Centigrade thermometers are used on the continent ot Europe. Of these two, the first is generally used in Germany, and the second in France, but the latter is almost exclusively used by the scientists of all nations. . _ ^ . . , , In the Reaumur thermometer, the freezing and boiling points are placed at 0° and 80°, respectively. In the Centigrade, the freezing and boiling points are placed at 0° and 100°, respectively. _ ,. ., .. To Convert Fahrenheit Into Centigrade— (1) Subtract 32 and divide the remainder by 1.8, or multiply by f . A ... ... . , , If a Fahrenheit thermometer registers 16/°, what will be the register by a Centigrade thermometer ? 167 - 32 (167 - 32)5 1.8 = 75° Centigrade. 75° Centigrade. To Convert Centigrade Into Fahrenheit. — (1) Multiply by 1.8, or f, and add 32. • Ars 75°, what will be the register by a If the Centigrade thermometer registers Fahrenheit thermometer? 75 X 1.8 + 32 = 167° Fahrenheit. + 32 167° Fahrenheit. To Convert Fahrenheit Into Reaumur.— (1) Subtract 32, and divide by 2.25, ° r mhe'Fahrenheit thermometer registers 113°, what will be the register by the Reaumur thermometer? 113 — 32 2.25 = 36° Reaumur. I 113 — 32 ^ = 36° Reaumur. 9 To Convert Reaumur Into Fahrenheit— (1) Multiply by 2.25, or multiply by f, If the Reaumur thermometer registers 36°, what will be the register by the Fahrenheit thermometer? 36 X 2.25 + 32 = 113° Fahrenheit. + 32 = 113° Fahrenheit. To Convert Reaumur Into Centigrade.— Multiply by 1-25. . . If a Reaumur thermometer registers 32°, what will be the register by a Centigrade thermometer? 32 X 1.25 = 40° Centigrade. To Convert Centigrade Into Reaumur.— Multiply by .8. . . If a Centigrade thermometer registers 40°, what will be the register by a Reaumur thermometer? 40 x .8 = 32° Reaumur. Calculation of Mine Resistance— The mine resistance is equal to the total pressure p a that it causes. This mine resistance is dependent upon tnree factors: (a) The resistance k offered by 1 sq. ft. of rubbing surface to a current naving a velocity of 1 ft. per minute. The coefficient of friction k, or the unit of resistance , is the resistance offered by the unit of rubbing sur- face to a current of a unit velocity. This unit resistance has been variously estimated by different authorities (see following table). The value most universally accepted, however, is that known as the Atkinson coefficient THE EQ UIVALENT ORIFICE. 367 (.0000000217). (b) The mine resistance, which varies as the square of the velocity. ( c ) The rubbing surface. Hence, if we multiply the unit resist- ance by the square of the velocity, and by the rubbing surface, we will obtain the total mine resistance as expressed by the formula pa = ksv *. Table of Various Coefficients of Friction of Air in Mines. Pressure per Sq. Ft. Decimals of a Pound. J. J. Atkinson’s treatise A. Devillez in Ventilation des Mines: Forchies - Crachet-Picquery Grand Baisson Average of 2, 3, and 4 Used in Ventilation des Mines Arched Tunnels Along a working face of coal G. G. Andre, Atmosphere of Coal Mines Peclet, Cheminee (Devillez, p. 112) j) Clark According to Goupiiliere’s Cours d’ Exploitation des Mines, Vol. II, p. 389: D’Aubuisson - Navier W. Fairley J. Stanley James D. Murgue .0000000217 .000000008211 .000000008928 .000000008611 .000000008585 .000000009511 .000000002113 .000000014266 .000000022424 .000000003697 .000000002272 .000000001955 .000000001872 .00000001 .00000000929 .000000008242 It will be observed that J. J. Atkinson’s coefficient is greatly in excess of any other, with the exception of Andre’s. Fairley’s is derived from an average taken between Atkinson, Devillez, and Clark, and, undoubtedly, it is an exceedingly simple coefficient to work out calculations with, as it will save a great mass of figures. James, in his work on colliery ventilation, reduces the coefficient still further on the authority of the Belgian Mine Commission, but he gives a most unwieldy figure to use. Atkinson’s figure is the one most in use, and if it is too high, it errs on the side of safety, and it is always advisable to have plenty of spare ventilating power at a mine. For this reason, and until a regular and thorough investi- gation, made by a commission of competent men, provides a standard coef- ficient, we prefer to abide by Atkinson’s coefficient, and it is used in all our calculations Calculation of Power, or Units of Work per Minute. — If we multiply the total pressure by the velocity (feet per minute) with which it moves, we obtain the unite of work per minute, or the power upon the air. Hence, u = pav = ksv* which isrthe fundamental expression for work per minute , or power. The Equivalent Orifice.— This term, often used in regard to ventilation, evaluates the mine resistance, or, as will be seen from the equation given below for its value, it expresses the ratio that exists between the quantity of air passing in an airway and the pressure or water gauge that is produced by the circulation. This term was suggested by M. Daniel Murgue, and refers to the flow of a fluid through an orifice in a thin plate, under a given head. The formula expressing the velocity of flow through such an orifice is v = 1 / 2 gh] multiplying both members of this equation by A, and substi- tuting for the first member A v, its value q , we have, after transposing and correcting for vena contracta, A = - , in which .62 is the coefficient for .62y 2 g h the vena contracta of the flow. Reducing this to cubic feet per minute and inches of water gauge represented by i , we have, finally, the equation A = .0004 X —7=. By this formula, Murgue has suggested assimilating the V i flow of air through a mine to the flow of a fluid through a thin plate; since, in each case, the quantity and the head or pressure vary in the same ratio. Thus, applying this formula to a mine, Murgue multiplies the ratio of the quantity of air passing (cubic feet per minute) and the square root of the water gauge (inches) by .0004, and obtains an area A , which he calls the equivalent orifice of the mine. . , „ Potential Factor of a Mine. ( Proposed by J. T. Beard.) — Equations 8 and 27, 368 VENTILATION OF MIXES. pages 370-371, give, respectively, the pressure and the power that will circu- late a given quantitv of air per minute in a given airway. These equations may be written as equal ratios, expressed in factors of the current and the * T) Jc s u k s airway, respectively; thus, — = — ^ , and — = which show that the ratio between the pressure and the square of the quantity it circulates in any given airwav is equal to the ratio between the power and the cube of the quantity it circulates. Solving each of these equations with respect to q, we have the following: With respect to pressure, *- ( a \i rs)^- With respect to power, *“ (rny*- Hence, we observe that, in any airway, for a constant pressure , the quan- tity of air in circulation is proportional to the expression a-y and, for a constant power , the quantity is proportional to the expression which terms are called the potentials of the mine with respect to pressure and power, respectively; and their values — — and are the potentials of the Vp current with respect to pressure and power, respectively. These factors, it will be observed, evaluate the airway, as they determine the quantity of air a given pressure or power will circulate in that airway (cubic feet per minute). Bv their use. the relative quantities of air any given pressure or power will circulate in different airways are readily determined. The rule mav be stated as follows: . . . Rule. — For any given pressure or power, the quantity of air in circulation is always ' proportional to the potential for pressure, or the potential for power , as the case may he. This rule finds important application in splitting (see Calculation of Natural Splitting) . In all cases where the potential is used as a ratio, the relative potential maybe employed by omitting the factor k; or it may be employed to obtain the pressure and power, in several splits by multiplying the final result by k (see Formulas 46, 47, etc., page 378). Example.— 20,000 cu. ft. of air is passing in a mine in which the airway is 6 ft. X 8 ft., and 10.000 ft. long, under a certain pressure; it is required to find what quantity of air this same pressure will circulate in a mine in which the airwav is 6 ft. X 12 ft., and 8,000 ft. long. Calculating the potential X p with respect to the pressure for each of these mines, or airways, we have, using the relative potential, Xi= 6X8< 6X8 6X12 — .62845, and X 2 — 6 X 12^ 2 (6 + J2) x 8,000 \ 2(6 + 8) X 10,000 = 1.1384. Since the ratio of the quantities is e^ual to the ratio of the potentials with respect to pressure, in these two mines, we write the propor- 20,000 X 1.1384 .62845 = 36,229 cu. ft. per tion 20,000 : q 2 : : .62845 : 1.1384, and q 2 = min. . . . . . ,, Example.— 20,000 cu. ft. of air is passing in a mine in which the airway is 6 ft. X 8 ft., and 10,000 ft. long, under a certain power; it is required to find what quantity of air will be circulated by this same power m a mi ne in which the airway is 6 ft. X 12 ft., and 8,000 ft. long. We calculate the potential X u with respect to power for each of these 6X8 mines, using, as before, the relative potential. Thus, X\ = ^ io 000 -- .7337, and X 2 6X 12 f 2(6 1.0905. Then, in this case, since the 12)X 8,000 ratio of the quantities is equal to the ratio of the potentials with POTENTIAL FACTOR. 369 respect to power, we write the proportion, 20,000 : q% : : .7337 : 1.0905, and a = 20,000 X 1^0905 _ 29 726 cu. ft. per min. v2 7337 The following table will serve to illustrate the use of the formulas employed in these calculations. It will be observed that there are several formulas for quantity, and for velocity, and for work or horse- power, but in each respective case the several formulas are derived by simple transposition of the terms of the original formula, and are tabulated here for convenience. Choice must be made in the use of any of these for- mulas, according to the known terms in each example. . Thus, an example mav ask- What pressure will be produced in passing a given quantity of air through 'a certain mine, the size and length of the airways being given? We then use the formula p = if t ^ ie question asks what quan- tity of air a given pressure will produce in this same mine, we use the formula q -4 pa ks Xfl. It will be observed that this second formula is a simple transposition of the first. , „ , x ... , In like manner the question maybe asked, what power will produce a certain quantity of air in a certain airway; and the expression used, in this case, is u = k S y~. Or, the question may be asked, what quantity of air will be produced in a given airway by means of a certain power^or work applied to the airway. In this case, the formula used is q = If the fic- tion asks for the power required to produce a given velocity in a fiven air- way the formula employed is u = ksv s . All of these formulas are derived by combining the simple formulas p = — — , q = av, and u = qp. To illustrate the use of the formulas, we take as an example an under- ground road, 5 ft. wide by 4 ft. high, and 2,000 ft. in length, and calculate the value of each symbol or letter, assuming a velocity of 500 ft. per minute. Symbol. Value of Symbol for this Particular Example. Area of airway (5 ft. X 4 ft.) tinrconowpr ♦ a h 20 sq. ft. 2.959 H. P. Pnoffipipnt of friction + k .0000000217 lb. VUCUILIV/Ilt VII llibtlL/ll | T nn rrfVi rtf* QirWflV l 2,000 ft. ±J0IlgXIl U1 dll WdJ • • • Perimeter of airway, 2(5 ft. + 4 ft.) Pressure (lb. per sq. ft.) nna-nfitxr r»f nir fpn ft, ner mm. ) 0 P q 18 ft. 9.765 lb. 10,000 cu. ft. quantity ui an it. A rna nf rnhhiTiP 1, SlirftinP s 36,000 sq. ft. AltJd UI lUUUIllg ouiiavyt Units of work per minute (power) Volnpitv (ft ripr min ^ u V 97,650 ft.-lb. 500 ft. V clUtltj \ A o* pci min. ; Wotpr an n orp i 1.87788 ip. vv dtei gdugu - TTmiiirolorit nrifipp nf flip TTVlTlfi A 2.919 sq. ft. JjU UlValcIll UllliUC ui tiiv ■prktori+ml fnr nowpr X u 217.16 units. i UtUlltldl lUi pu vv Cl ■pz-ktcntial fnr* tytpwii re X v 3,200 units. I Utt/Utldl 1U1 piCOOUlC Weight of 1 cu. ft. of downcast air Motive column (downcast air) moYvfVi nf fnrnflPP shaft, P W M D .08098 lb. 120.5 ft. 306.77 ft. Average temperature of the upcast column.. Average temperature of the downcast column T t 350° F. 32° F. *A horsepower is equal to 33,000 units of work. . , , . t This coefficient of friction is an invariable quantity, and is the same in every calculation relating to the friction of air in mines. Note.— The water gauge is calculated to five decimal places to enable all the other values to be accurately arrived at. In practice, it is only read to one decimal place. 370 VENTILATION OF MINES. FORMULAS. On the right side of each formula, the various calculations, based on the example given, are worked out in figures. To Find: No. Formula. • Specimen Calculation. Rubbing sur- face of an air- way. (Sq.ft.) 1 s — l 0 2,000 X 18 = 36,000 sq. ft. Area of an airway. (Sq.ft.) 2 a = — V 20 sq. ft. of area. ouU Velocity. (Ft. per min.) 3 II ^^ = 500 ft. 4 3 / U V ” \ks si 97,650 \ .0000000217 X 36,000 5 v J Va 1 9.765X20 \ ks \ .0000000217 X 36,000 6 u 97,650 cqq «■ 9.765 X 20 500 * ~ pa Pressure. 7 ksv 2 .0000000217 X 36,000 X 500 2 n (Lb. persq. ft.) P a 20 ~ 9./6D1D. 8 k sq 2 J .0000000217 X 36,000 X 10,000 2 20 s = 9.765 lb. 9 II |g 10 p = Mw 120.58 X .08098 = 9.765 lb. 11 p — 5.2 i 5.2 X 1.87788 = 9.765 lb. 12 II hk cel 13 II Sc Water gauge. (Inches.) 14 i - 5.2 9 '™ 5 = 1.87788 in. Resistance of an airway. (Total pressure, 15 16 pa = ksv 2 u pa = - * V .0000000217 X 36,000 X 500 2 = 195.31b. 9 ^° = 195.3 n>. FORMULAS. 371 To Find: 1 No. Formula. | 1 Specimen Calculation. Quantity. 17 q == av 20 X 500 = 10,000 cu. ft. (Cu.ft.per min) ►c It •e 18 97 650 18 y/,oou = 1Q 000 cu ft 9.765 19 1 9.765 X 20 \ .0000000217 X 36,000 = 10,000 cu. ft. 20 9 = ^ Xa 3 1 97,650 ^ 0 q \ .0000000217 X 36,000 = 10,000 cu. ft. 21 q = X u fu 217.16 X ^ 97,650 = 10,000 cu. ft. 22 q = fX/u ^3,2002 X 97,650 = 10,000 Cu. ft. 23 q = X p Vp 3,200 X V 9-765 = 10,000 cu. ft. Units of work 24 u = avp 20 X 500 X 9.765 = 97,650 ft.-lb. per minute, or power on the 25 II 8 10,000 X 9.765 = 97,650 ft.-lb. air. (Ft.-lb.permin) 26 u = ksv* .0000000217 X 36,000 X 500 3 = 97,650 ft.-lb. ks q 3 .0000000217 X 36,000 X 10,000 3 27 U ~~ a 3 20 3 = 97,650 ft.-lb. 28 u = h 33,000 2.959 X 33,000 = 97,650 ft.-lb. 29 q z u = x~z ■A-u = 97,650 ft.-lb. 30 q 3 - 97 - 65oft - ib - Horsepower. 31 h U “ 33,000 = 2.959 H. P. 33,000 Power poten- tial. (Units.) 32 | w ° £ II 20 — 217.16 units. ^ .0000000217 X 36,000 33 1 * 1 *. II Hi j/lO’OOO 2 - 217.16 units. \ 9.765 ■y q 10,000 _ 2^7 i6 units. 34 ■A-u — O/— fn ^97,650 372 VENTILATION OF MINES. To Find: No. Formula. Specimen Calculation. Pressure poten- tial. (Units.) 35 r 36 H & f " 11 S •ell *|a Co 1 1 20 „ 20 \ .0000000217 X 36,000 = 3,200 units. - Q - Q ° = 3,200 Units. V 9.765 Equivalent orifice. (Sq. ft.) 37 .0004 q Vi .0 004 X 10 ,°°0 — 2.919 sq. ft. 1/1.87788 Motive column, downcast air. (Feet.) 38 39 K - 1>x 459+r M = - P - w 30M7x m + ^ - m5ft - Motivecolumn, upcast air. (Feet.) 40 39 M = 2 - w 306 - 77x !“;32- m7ft ; mZ = m7ft - Variation of the Elements.— In the illustration of the foregoing table, we have assumed fixed conditions of motive column, as well as fixed conditions in the mine airways. It is often convenient, however, to know how the different elements, as velocity v, quantity q, pressure p, power u, etc., will vary in different circulations; since we may, by this means, compare the circulations in different airways, or the results obtained by applying different pressures and powers to the same airway. These laws of variation must always be applied with great care. For example, before we can ascertain how the quantity in circulation will vary in different airways, we must -mow whether the pressure or the power is constant or the same for each hrway. The following rules may always be applied: For a constant pressure: v varies as q varies as (relative poten- tial for pressure). For a constant power: varies as q varies as — ^ (relative potential for power). For a constant velocity: q varies as a; p varies as — ; u varies as lo. For a constant quantity: v varies inversely as a; p varies inversely as X u 3 (potential for power); u varies inversely as X M 3 (potential for power) or directly as p. For the same airway: The following terms vary as each other: v , q, Vp, fu. Similar Airways. v = length of similar side, or similar dimension. For a constant pressure: v varies as ^ j ; q varies as r 2 X rvariesas lv 2 , or V lq 2 . DISTRIBUTION OF AIR. 373 1. 3 jr 2 For a constant power: v varies as q varies as r X yjj ; r varies as r ^ or ^« 3 For a constant velocity: q varies as r 2 ; p varies as u varies as Ir; /-l u r varies as y g, or For a constant quantity: v varies inversely as r 2 ; p and u vary inversely as or Furnace Ventilation. p (motive column) varies as D; q varies as j/ D. Fan Ventilation. r b . l , ; r varies as — — * V*' It has been customary in calculations pertaining to the yield of centrif- ugal ventilators to assume as follows: q varies as n; p varies as ?i 2 ; u varies as n 3 . More recent investigation, however, shows that when we double the speed we do not obtain double the quantity of air in circulation; or, in other words, the quantity does not vary exactly as the number of revolutions of the fan. Investigation also points to the fact that the efficiency of centrif- ugal ventilators decreases as the speed increases. To what extent this is the case has not been thoroughly established. The variation between the speed of a fan and the quantity, pressure, power, and efficiency, as calculated from a large number of reliable fan tests, may be stated as follows: Forthesamefan, discharging against a constant potential: q varies as n- 91 . p varies as it 1 * 94 . Complement of efficiency (1 — K) varies as w 425 . The efficiency here referred to is the mechanical efficiency , or the ratio between the effective work qp and the theoretical work of the fan. DISTRIBUTION OF AIR IN IWNE VENTILATION. When a mine is first opened, the air is conducted in a single current around the face of all the headings and workings, and returns again to the upcast shaft, where it is discharged into the atmosphere. As the develop- ment of the mine advances, however, it becomes necessary to divide the air into two or more splits or currents. This division or splitting of the air- current is usually accomplished at the foot of the downcast, or as soon as possible after the current enters the mine. There are several reasons why the air-current should be thus divided. The most important reason is that the mine is thereby divided into separate districts, each of which has its own ventilating current, which may be increased or decreased at will. Fresh air is thus obtained at the face of the workings, and the ventilation is under more perfect control. It often happens that certain portions of a mine are more gaseous than others, and it is necessary to increase the volume of air in these portions, which can be readily accomplished when each district has its own separate circulation. Again, the gases and foul air are not conducted from one district to another, but each district is supplied with fresh air direct from the main intake. Should an explosion occur in any part of the mine, it is more apt to be confined to one locality when a mine is thus divided into separate districts. Another consideration is the reduced power necessary to accomplish the same circulation in the mine; or the increased circulation obtained by the use of the same power. Requirements of Law in Regard to Splitting.— The Anthracite Mine Law of Pennsylvania specifies that every mine employing more than 75 persons must be divided into two or more ventilating districts, thus limiting the number that are allowed to work on one air-current to 75 persons. The Bituminous Mine Law of Pennsylvania limits the number allowed to work upon one current to 65 persons, except in special cases, where this number may be increased to 100 persons at the discretion of the mine inspector. Practical Splitting of the Air-Current— When the air-current is divided into two or more branches, it is said to be split. The current may be divided one or more times; when split or divided once, the current is said to be traveling 374 VENTILATION OF MINES . in two splits, each branch being termed a split. The number of splits in which a current is made to travel is understood as the number of separate currents in the mine, and not as the number of divisions of the current. Primary Splits.— When the main air-current is divided into two or more splits, each of these is called a primary split. . Secondary Splits. — Secondary splits are the divisions of a primary split. Tertiary Splits.— Tertiary splits result from the division of a secondary split. Equal Splits of Air.— When a mine is spoken of as having two or more equal splits, it is understood to mean that the length and the size of the separate airways forming those splits are equal in each case. It follows, of course, from this that the ventilating current traveling in each split will be the same, inasmuch as they are all subject to the same ventilating pressure. When an equal circulation is obtained in two or more splits by the use of regulators, these splits cannot be spoken of as equal splits. * Unequal Splits of Air.— By this is meant that the airways forming the splits are of unequal size or length. Under this head we will consider (a) Natural Division of the Air- Current; ( b ) Proportionate Division of the Air- Current. Natural Division of the Air-Current.— By natural division of air is meant any division of the air that is accomplished without the use of regulators; or, in other words, such division of the air-current as results from natural means. If the main air-current at any given point in a mine is free to traverse two separate airways in passing to the foot of the upcast shaft, and each of these airways is free or an open split, i. e., contains no regulator, the division of the air will be a natural division. In such a case, the larger quantity of air will always traverse the shorter split of airway. In other words, an air-cur- rent always seeks the shortest way out of a mine. A comparatively small current, however, will always traverse the long split or airway. Calculation of Natural Splitting.— It is always assumed, in the calculation of the splitting of air-currents, that the pressure at the mouth of each split, starting from any given point, is the same. Since this is the case, in order to find the quantity of air passing in each of several splits starting from a common point, the rule given under Potential Factor of a Mine is apphed. This rule may be stated as follows: The ratio between the quantity of air passing in any split and the pressure potential of that split is the same for all splits starting from a common point. Also the ratio between the. entire quantity of air in circulation in the several splits and the sum of the pressure potentials of those splits is the same as the above ratio, and is equal to the square root of the pressure. Expressed as a formula, indicating the sum of the pressure potentials (Xi + X 2 + etc.) by the expression 2I P , this rule is = Jr = V P- Hence, p = and u = express the pressure and power, (2J P ) 2 ~ (2X P ) 2 . . _ respectively, absorbed by the circulation of the splits. These are the basal formulas for splitting, from which any of the factors may be calculated by transposition. They will be found illustrated in the table at the end of this section. We will give here two examples only, showing the calculation of the natural division of an air-current between several splits. \\ e have, from Xi ^ the above formulas, q\ = ^ ^ Q. Example. — In a certain mine, an air-current of 60,000 cu. ft. perminute is traveling in two splits as follows: Split A, 6 ft. X 8ft., 5,000 ft. long- split B, 5 ft. X 8 ft., 10,000 ft. long. It is required to find the natural division of this air-current. . , , . , r+ Calculating the relative potentials for pressure in each split, we have for split A for split B, X 2 .*1 -«Vs = 4 °^ 48 2(6 + 8)5,000 40 2(5 + 8)10,000 = .4961 and 2 X p = 1.3849; and substituting these values, we have, Qi Q2 - v 60,000 = 38,506 cu. ft. per min.; 1.3849 x 60.000 = 21,494 cu. ft. per min. 1.3849 and DISTRIBUTION OF AIR. 375 Example.— In a certain mine, there is an air-current of 100,000 cu. ft. per minute traveling in three splits as follows: Split A, 6 ft. X 10 ft., 8,000 ft. long; split B , 6 ft. X 12 ft., 15,000 ft. long; split C, 5 ft. X 10 ft., 6,000 ft. long. Find the natural division of this current of air. Calculating the respective relative potentials with respect to pressure, we have for split A X, = 60 y 2(6 + 1 ff x8 , 000 - -9185; for split B, X t = 72 ^ + - .8314; for split C, X 3 = 50 V 2(5 + 10 rx 6 , - 60b = ' 8833 ' Adding these potentials, we have 2 X p = .9185 + .8314 + .8333 = 2.5832. Then, applying the foregoing rule, we have qi = X 100,000 = 35,556 cu. ft. per min.; « 2 = ~~ X 100,000 = 32,184 cu. ft. per min.; QQOO and x 100 ’ 000 = 32,260 cu - ft - P er min - Total, 100,000 Proportional Division of the Air-Current.— It continually happens that differ- ent proportions of air are required in the several splits of a mine than would be obtained by the natural division of the air-current. It is usually the case that the longer splits employ a larger number of men, and require a larger quantity of air passing through them. They, moreover, liberate a larger quantity of mine gases, for which they require a larger quantity of air than is passing in the smaller splits. The natural division of the air-current would give to these longer splits less air, and to the shorter ones a larger amount of air, which is directly the reverse of what is needed. On this account, recourse must be had to some means of dividing this air pro- portionately, as required. This is accomplished by the use of regulators, of which there are two general types, the box regulator and the door regulator. Box Regulator. — This is simply an obstruction placed in those airways that would naturally take more air than the amount required. It consists of a brattice or door placed in the entry, and having a small shutter that can be opened 1 to a greater or less amount. The shutter is so arranged as to allow the passage of more or less air, according to the requirements. The box regulator is, as a rule, placed at the end or near the end of the return air- way of a split. It is usually placed at this point as a matter of convenience, because, in this position, it obstructs the roads to a less extent, the haulage from the back entry in this split being carried over to the main haulway, through a cross-cut, before this point is reached. The difficulty, however, can be avoided, in most cases, by proper consideration in the planning of the mine with respect to haulage and ventilation. The objection to this form of regulator is that, in effect, it lengthens the airway, or increases its resistance, making the resistance of all the airways, per foot of area, the same. It is readily observed that, by thus increasing the resistance of the mine, the horsepower of the ventilation is largely increased, for the same circulation. This is an important point, as it will be found that the power required for ventilation is thus increased anywhere from 50$ to 100$ over the power required when the other form of regulator can be adopted. Door Regulator.— In this form of regulator, which was first introduced by Beard, the division of the air is made at the mouth of the split. The regu- lator consists of a door hung from a point of the rib between two entries, and swung into the current so as to cut the air like a knife. The door is provided with a set lock, so that it may be secured in any position, to give more or less air to the one or the other of the splits, as required. The posi- tion of this regulator door, as well as the position of the shutter in the box regulator, is always ascertained practically by trial. The door is set so as to divide the area of the airway proportionate to the work absorbed in the 376 VENTILATION OF MINES. respective splits. The pressure in any split is not increased, each split retaining its natural pressure. . . . , Calculation of Pressure for Box Regulators— When any required division of the air-current is to be obtained by the use of box regulators, these are placed in all the splits, save one. This split is called the open, or free, split, and its pressure is calculated in the usual way by the formula p = ~as~' The natural pressure in this open split determines the pressure of the entire mine, since all the splits are subject to the same pressure in this form of ^ First* determine in which splits regulators will have to be placed, in order to accomplish the required division of the air. Calculate the natural pres- sure, or pressure due to the circulation of the air-current, for each split, when passing its required amount of air, using the formula p = ^ The split showing the greatest natural pressure is taken as the free split. In each of the other splits, box regulators must be placed, to increase the pressure in those splits; or, in other words, to increase the resistance of those splits per unit of area. . , . . Example. — The ventilation required m a certain mine is: split A , 6 ft. X 9 ft., 8,000 ft. long; 40,000 cu. ft. per min. split B , 5 ft. X 8 ft., 6,000 ft. long; 40,000 cu. ft. per min. split a 9 ft. X 9 ft., 8,000 ft. long; 10,000 cu. ft. per min. split D, 6 ft. X 8 ft., 10,000 ft. long; 30,000 cu. ft. per mm. In which of these splits should regulators be placed, to accomplish the required division of air, and what will be the mine pressure? . Calculating the pressure due to friction in each split when passing its required amount of air, we find, .0000000217 X 2(6 + 9)8,000 X 40,0002 ' 5# ~ .0000000217 X 2(5 + 8)6,000 X 40.0002 ~40* .0000000217 X 2(9 + 9)8,000 X 10 . 000 2 81 3 .0000000217 X 2(6 + 8 )10,000 X 30,0 002 = 49 45 lb per sq ft for split A, p = for split B, p = for split C, p = = 52.92 lb. per sq. ft.; = 84.63 lb. per sq. ft.; = 1.176 lb. per sq. ft.; for split D, p = 48 * Split B has the greatest pressure, and is therefore the free split. Box regulators are placed in each of the other splits to increase their respective pressures to the pressure of the free split or the mine pressure. Therefore, the mine pressure in this circulation is 84.63 lb. per sq. ft. _ The Size of opening in a box regulator is calculated by the formula for determining the flow of air through an orifice in a thin plate under a certain head or pressure. The difference in pressure between the two sides of a box regulator is the pressure establishing the flow through the opening, which corresponds to the head h in the formula v = \Z%9 h -. This regulator is usually placed at the end of a split or airway, and since the regulator increases the pressure in the lesser split so as to make it equal to the pressure in the other split, the pressure due to the regulator will be equal to the ventilating pressure at the mouth of the split, less the natural . pressure or the pressure due to friction in this split. Hence, when the position of the regulator is at the end of the split, the pressure due to friction m the split is first calculated by the formula p = ^- 2 , and this pressure is deducted from the ventilating pressure of the free or open split, which gives the pressure due to the regulator. This is then reduced to inches of water gauge, and .OCKHq Tbe va ] ue 0 f ^ thus obtained is substituted for i in the formula A — V K the area (square feet) of the opening in the regulator. Example.— 50,000 cu. ft. of air is passing per minute m a certain mine, in two equal splits, under a pressure equal to 2 in. of water gauge, and it is required to reduce the quantity of air passing m one of these splits, by a box regulator placed at the end of the split, so as to pass but 15,000 cu. ft. per DISTRIBUTION OF AIR. 377 minute in this split. Find the area of the opening in the regulator, assu- ming that the ventilating power is decreased to maintain the pressure con- stant at the mouth of the splits after placing the regulator. The size and length of each split is 6 ft. X 10 ft. and 10,000 ft. long. . , „ ^ The natural pressure for the split in which the regulator is placed will be .0000000217 X 2(6 + 10) X 10, 000 X 15, OOP 2 = ? m lb per sq> _ ksq 2 __ a 3 Then, 7.233 5.2 (6 X 10) 3 1.4 in. of water gauge (nearly), due to friction of the air- current in this split. „ . .0004 q Finally, A = — j=- - V And, 2 — 1,4 = .6 in. water gauge due to regulator. .0004 X 15,000 V -6 = 7.746 sq. ft., area of opening. Size of Opening for a Door Regulator.— The sectional area at the regulator is divided proportionately to the work to be performed in the respective splits according to the proportion A\ : A 2 :: U\ : u 2 . Or since A\-t A 2 = a, we have A\ :a :: U \ : u x + u 2 , and A x = — X a. This furnishes a method of pro- portionate splitting in which each split is ventilated under its own natural pressure. The same result would be obtained by the placing of the box regulator at the intake of any split, thereby regulating the amount of air passing into that split, but the door regulator presents less resistance to the flow of the air-current. The practical difference between these two forms of regulators is that in the use of the box regulator each split is ventilated under a pressure equal to the natural pressure of the open or free split which very largely increases the horsepower required for the ventilation of the mine- while in the use of the door regulator each split is ventilated under its own natural pressure, and the proportionate division of the air is accomplished without any increase of horsepower. This is more clearly . , x — — -• — — h s , and the table showing the corn- explained in the two following parai parative horsepowers of the two methods. Calculation of Horsepower for Box Regulators.— By the use of the box regu- lator, the pressure in all the splits is made equal to the greatest natural pressure in any one. This split is made the open or free split, and its natural pressure becomes the pressure for all the splits, or the mine pressure. This mine pressure, multiplied by the total quantity of air in circulation (the sum of the quantities passing in the several splits), and divided by 33,000, gives the horsepower upon the air, or the horsepower of the circulation. Thus, in the first example given on page 376, in which for split B the pressure p = 84.63 lb. per sq. ft. and the total quantity of air passing per minute is 120,000 cu. ft., we have Calculation of Horsepower for Door Regulators. — In the use of the door regulator, each split is ventilated under its own natural pressure, and, hence, in the calculation of the horsepower of such a circulation, the power of each split must be calculated separately, and the sum of these several powers will be the entire power of the circulation. For the purpose of com- parison, we tabulate below the results obtained in the application of these two methods of dividing the air in the above example. Splits. Natural Division. Required Division. Horsepower. Door Regulator. Box Regulator. Split A, 6 ft. X 9 ft., 8,000 ft. long Split B, 5 ft. X 8 ft., 6,000 ft. long Split C, 9 ft. X 9 ft,, 8,000 ft. long Split D, 6 ft. X 8 ft., 10, 000 ft. long Totals 28,277 22,360 47,423 21,940 40,000 40.000 10.000 30,000 64.145 102.582 .356 1 44.955 102.582 102.582 25.645 76.936 120,000 1 120,000 212.038 307.745 378 VENTILATION OF MINES SPLITTING FORMULAS The following table of formulas will serve to illustrate the methods of calculation in splitting. The example assumes the same airway as that given on page 369 and used to illustrate the table of formulas, page 370, but the air- current is divided, as specified in the table: Natural Division. Primary Splits— Split (1) = 4 ft. X 5 ft., 800 ft. long. Split (2) = 4 ft. X 5 ft., 1,200 ft. long. To Find: No. Formula. Specimen Calculation. Potential for pressure. 35 Y n 1 a x *~ a \lks' U ? = (Xx + X 2 + etc.). (1) 20 ^ 00000 oo 217x14 , 4 oo 5 ’ 060 ' / 20 _ . (2) 20 0000000217 X 2b 600 5,060 + 4,131 = 9191. Natural divi- sion. 41 X v q ~ 2 X p X Q ' (1) X 10,000 = 5,505 cu. ft. (2) ^lli x 10,000 = 4,495 cu ‘ ft ' Or the natural division may be calculated from the pressure at the mouth of the several splits by using formula (23); thus, 23 q^X p \/ p. (1) 5,060 ]/ 1.1838 = 5,505 cu. ft. (2) 4,131 V 1.1838 = 4,495 cu. ft. See formula (42). Pressure. 42 Q 2 P (2 X p )* Power. 43 Q 3 (zx„r Quantity. 44 45 Q = S.X p y'p. <2 = X p )-w. 9,191 V 1.1838 = 10,000 cu. ft. 1^9, 191 2 X 11,838 = 10,000 cu. ft. Increase of quantity due to splitting. (Pressure con- stant. ) 46 2 X p Q = -X •A-p — O Q 191 i~j~ X 10,000 = 28,722 cu. ft. Increase in quantity due to splitting. (Power con- stant.) 47 & It 10,00 °-V(|^) 2 = 20,205 CU,ft SPLITTING FORMULAS 379 500 ft. long. Secondary Splits. — (1) 4 ft. X 5 ft., 800 ft. Jong. (2) 4 ft. X 5ft (3) 4 ft. X 5 ft., 400 ft. long. (4) 4 ft. X 5 ft., 300 ft. long. The calculation is often shortened, when many splits are concerned, by using the relative potential , omitting the factor A;; but the final result must then be multiplied by k to obtain the pressure or power; or, these factors must be divided by Ac, when finding the quantity, as in formulas (49) to (51). tH Oi O rH iO iO o3 jq fH O P*5S fH 3 t « fH* 3 p 55 09 0> M £ o I to* P. P a 5 2 *3 o.o3 2 pj* Ph’43 Pi 380 VENTILA TIOX OF MIXES. Proportionate Division. Primary Splits (only).— (1) 4 ft. X 5 ft., 800 ft. long = 3,500 cu. ft. (2] 4 ft. X 5 ft., 1,200 ft. long = 6,500 cu. ft. To Find: No. Formula. Specimen Calculation. Pressure due to friction. 13 (f P X 2* (1) S--"- (2) IS = 2 - 4757,b - To accomplish this division of air, the pressure in split (1) must be increased by means of a regulator to make it equal to the pressure in the free or open split (2), and, hence, the pressure due to the regulator is equal to the difference between the natural pressures in these splits. Pressure due to the regulator in split (1). 53 P = P-2 — Pi- 2.4757 — .47845 = 1.99725 lb. Area of the opening in regulator. 37 , _ .0004 q ^ /— * V * .0004 X 3,500 _ 2 259 gq ft 1.99725 \ 5.2 Secondary Splits.— (1) 4 ft, X 5 ft., 800 ft. — 3,500 cu. ft. (2) 4 ft. X 5 ft., 500 ft. — 6,500 cu. ft. (3) 4 ft. X 5 ft., 400 ft. — 4,000 cu. ft. (4) 4 ft. X 5 ft., 300 ft. — 2,500 cu. ft. Note— When using the relative potential, multiply the result by k, to obtain the pressure, or the power. Pressure due to friction. Free split-second- ary pressure. 13 *8 11 J (1) .0000000217 2 =- -47848 lb. (2) .0000000217 = 1.0314 lb. (3) -0000000217 = -31248 lb - (4) .0000000217 (£^)* = .0915461b. V 1.2172 / Since the natural pressure in (3) is greater than that in (4), (3) is the free split, and its natural pressure is the pressure for the secondary splits. The pressure for the primary splits is then found by first adding the pressures in (2) and (3), and if their sum is greater than the natural pressure for (1), it becomes the pressure for the primary splits, or the mine pressure. If the natural pressure for (1) is the greater, this is made the free split, and its natural pressure becomes the primary or mine pressure. In this case, the secondary pressure must be increased by placing a regulator in split (3). Primary or mine pressure. P 2 +P 3 . 1.0314 + .31248 = 1.34388. Pressure due to P3 — Pi- (4) .31248 — .091546 = .220934 lb. the regula- 1 tors. (Pa + Pa)—Pi- (1) (1.0314 + .31248) — .47848 = .86540 lb. Areas of open- ings in the regulators. 37 i _ .0004 q Vi (4) • 0004 X 2 ' 500 - 4.85 1 4sa.ft. /.220934 M 5.2 (1) '° 004 X 3,500 = 3.4328 sq. ft. 1.8654 \ 5.2 METHODS AND APPLIANCES. 381 METHODS AND APPLIANCES IN THE VENTILATION OF MINES. Ascensional Ventilation.— Every mine, as far as practicable, should be venti- lated upon the plan known as ascensional ventilation. This term refers particularly to the ventilation of inclined seams. The air should enter the mine at its lowest point, as nearly as possible, and from thence be conducted through the mine to the higher points, and there escape by a separate shaft, if such an arrangement is practicable. Where the seam is dipping considerably and is mined through a vertical shaft, the upcast shaft should be located as far to the rise of the downcast shaft as possible. The intake air is then first conducted to the lowest point of the dip workings, which it traverses upon its way to the higher workings. In the case of a slope working where a pair of entries is driven to the dip, one being used as the intake and the other the return, there being cross-entries or levels driven at regular intervals along the slope, the air should be conducted at once to the inside workings, from which point it returns, ventilating each pair of cross- entries from the inside, outwards. Where the development of the cross- entries or levels is considerable, their circulation is considered separately, and a fresh air split is made in the intake at each pair of levels. In all ventilation, the main point to be observed is to conduct the air-current first to the inside workings, from whence it is distributed along the working face as it returns toward the upcast. General Arrangement of Mine Plan.— Every mine should be planned with respect to three main requirements, viz.: (a) haulage; ( b ) drainage; (c) ventilation. These requirements are so closely connected with one another that the consideration of one of them necessitates a reference to all. The mine should be planned so that the coal and the water will gravitate toward the opening, as far as possible. There are many reasons, in the consideration of non-gaseous mines, why the haulage should be effected upon the return airways. The haulage road is always a dusty road, caused by the traveling of men and mules, as well as by the loss of coal in transit, which becomes reduced to fine slack and powder. If the haulage is accomplished upon the intake entry or air-course, this dust is carried continually into the mine and working places, which should be avoided whenever possible. When the loaded cars move in the same direction as the return air, the ventilation of the mine is not as seriously impeded. It is often the case that fewer doors are required upon the return airway than upon the intake, which is a feature favorable to haulage roads. Again, in this arrangement, the hoisting shaft is made the upcast shaft, which prevents the formation of ice, and conse- quent delay in hoisting in the winter season. The arrangement, however, presupposes the use of the force fan or blower, since if a furnace or exhaust fan is employed, a door, or probably double doors, would have to be placed upon the main haulage road at the shaft bottom, which would be a great hindrance. In the ventilation of gaseous mines; however, other and more important considerations demand attention. The gaseous character of the return current prevents making the return airway a haulageway. In such mines, the haulage should always be accomplished upon the intake air, as any other system would often result in serious consequences. In such gaseous mine, men and animals must be kept off the return airways as far as this is possible. . As far as practicable, ventilation should be accomplished m sections or districts, each district having its own split of air from the main intake, and its own return connecting with the main return of the mine. Reference has been made to this under Distribution of the Air in Mine Ventilation. This splitting of the air-current is accomplished preferably by means of an air bridge, either an under crossing or an over crossing. There are, in general, three systems of ventilation, with respect to the ventilating motor employed: (a) natural ventilation; (b) furnace ventilation; (c) mechanical / VC71/t'i/l/CLt'i071/ Natural ventilation means such ventilation as is secured by natural means, or without the intervention of artificial appliances, such as the furnace, or any mechanical appliances by which the circulation of air is maintained. In natural ventilation, the ventilating motor or air motor is an air column that exists in the downcast shaft by virtue of the greater weight of the downcast air. This air column acts to force the air through the airways 382 VENTILATION OF MINES. of the mine. An air column always exists where the currents of air pass through a certain vertical height, and Afferent temperatures This is the case whether the opening is a shaft or a slope, since? in 'either case, there is a vertical height which ^ part determines the height of air column. The other factor determining the hei § h ^ of mr column is the difference of temperature between rfu^de^ticai The calculation of the ventilating pressure m natural ventilation is identical with that of furnace ventilation, which is described later. , lirnri ventilation of Rise and Dio Workings.— We have referred to the air column existing either in vertical shafts or slopes as the motive column or venti- Mng motor Such an air column will be readily seen to exist m any rise or din workings within the mine, and may assist or retard the circulation of the air-current through the mine. It is this air column that renders the ventilation of dip workings easy, and that of rise workings correspondingly difficult depending, however, on the relative temperature of the intekeaim return currents; the latter usually is the warmer of the two, i\hich gpwes rise to the air column. The influence of such air columns m ^{. al ^ a * jbe taken into account in the calculation of any ventilation. This is often neglected • • The influence of air columns in rise or dip workings, within the unne, becomes very manifest where, from any reason, the mam intake current is increased or decreased. For example, a mine is ventilated in two sphts, a rise and a dip split; a current of 50,000 cu. ft. of air is passing m the mam airwav, 30,000 cu. ft. passing into the dip workings, and 20,000 mto the roe workings. A fall of roof in the main intake airway, or other cause,reduces the main current from 50,000 to 35,000 cu. ft. Instead, now, of 21 , going to the dip workings and 14,000 to the nse workings, we find that this proportion no longer exists, but that the dip workings are taking more than their proportion of air, and the rise workings less. Thus the emulation being decreased to 35,000 cu. ft., the dip workings will ^ k h e Q ?°Vh^ cu. ft., and the rise workings 10,000 cu. ft. On the other hand, had the intake current been increased instead of decreased, the workings ^ would then take more than their proportion, while the dip workings would take less The reason for this distribution is evident; suppose, for example, the intake or mine pressure is 3 in. of water gauge, and m there is k in of water gauge acting to assist ventilation, whilea like water gauge ofi in in the ri^ workings lets to retard ventilation The effective water auge in the dip workings is therefore 3, in., while the effective w a nue in the rise workings is 21 in., or they are to each other as 7 . 5. If, now, the mine pressure is decreased to, say, 2 in., the^ effective nse and diD pressures will be, respectivelv, 2£ in. and 11 in., or as o : 3. e observe, before the decrease, the dip pressure was h or 1.4, times the i ^ P^^f e ’ while after the decrear iok place m the mine pressure, the dip pressure became for 1 M times the rise pressure. The relative quanUtiespa^ng m the dip split before and after the decrease took placets compared with the quantities passing in the rise split, will be as the V 1.4 : j/l.66, ?bowing an increase of proportion. Now, instead of a decrease taking piacemthemme pressure, let us suppose it is increased , say, from 3 in. to 4 m. The eff^tive pressures in t 1 lip and rise workings will then be, re ^ c k vel ^Jj “■ and 3£ in., or they will be to each other as 9:7, instead of 7. 5. Her e we observe that the dip pressure is If, or 1.15, times the nse pr^sure, instead of 1.4. The relative quantities, therefore, passing in the dip split, before and after the increase of the mine pressure, as compared with the quantities passing in the rise split, will be in the ratio of V 1.4 : l/l.lo. decrease of proportion. We observe that any alteration of the mm e sure bv which it is increased or decreased does not affect the inside dip or rise columns, and hence the disproportion obtains. In case of a dec^^ of the mine pressure, the dip workings receive more than p^^rtion of air, and in case of an increase of the mine pressure, they receive less tha i nfl uence of^Msons^-In any ventilation, air columns are always established in slopes and shafts, owing to the relative temperatures of the outade and inside 1 air. The temperature of the upcast, or return column, may always be assumed to be the same as that of the inside air The of the downcast, or intake column, generally approximates the tempw^^eof the outside air. although, in deep shafts or long slopes, this temperature imy be Changed considerably before the bottom of the shaft or slope is reached, and METHODS AND APPLIANCES 383 consequently the average temperature of the downcast or intake, is often different from that of the outside air. The difference of temperatures will also vary with the season of the year. In winter the outside temperature is below that of the mine, and the circulation in shafts and slopes is assisted, since the return columns are warmer and lighter than the intake columns for the same circulation. In the summer season, however, the reverse of this is the case. The course of the air-current will thus often be changed. When the outside temperature approaches the average temperature of the mine, there will be no ventilation at all in such mines, except such as is caused bv accidental wind pressure. „ . . , In furnace ventilation the temperature of the upcast column is increased above that of the downcast column by means of a furnace. The chief points to be considered in furnace ventilation are in regard arrange- ment and size of the furnace. Furnace ventilation should n6 o^ TbP factor c is a constant of design whose value may vary from 2 to 7. but en^o Stfc res^Jmw its e^^yforpa.^ the^mor P a£dwith straight radial blades having only a forward FAN CONSTRUCTION. 391 curve at the lip of the blade to avoid the shock of the entry air against the revolving blades, and the spiral casing starting a short distance upon the cut-off and extending uniformly around the circumference of the fan, the value of this constant may be 2 or 3. Where none of these accessories to the efficiency of the fan is employed, the value of c may be as high as 7. FAN CONSTRUCTION. Size of Central Orifice.— The velocity of the intake should vary between 1,000 ft. and 1,500 ft. per minute, while 1,200 ft. may be used for fan calcula- tions. If d = dia meter of opening, and q = quantity of air passing per minute, d = ^ ^0 x 7 ? 854 fOT sin S le - intake faIls ’ and d = V^400 X .7854 for double-intake fans. Upon entering the fan the air travels in a radial direction; this change of direction is accompanied by a slight reduction of the velocity, hence the throat area of the fan must be slightly in excess of the intake area. The throat is the surface of the imaginary cylinder that has for its two bases the two intake openings of the fan, and for its length the width of the fan, = ndb. [The throat area is commonly made 1.25 times the total area of the intake orifices, which gives for breadth of blade b = f d for double intake, and b = T % d for single intake. — Beard.] Diameter of Fan.— Murgue assumes the tangential velocity of the blade tips (it) to create a depression double that due to the velocity as expressed by the equation H = — , or if the manometrical efficiency = K , and the* rfi la h effective head produced = h, h = K H = K — , or m= ^ If' From this equation, the tangential velocity (feet per second) may be calculated for any given effective head h. This effective head h is the head of air column effective in producing the circulation in the airway. To convert the effective head of air column into inches of water gauge (£), we have h = ^ 2 )<°i2 Hav ^ 11 8' f° un( l the tangential speed required in feet per second, this is multiplied by 60, to obtain the speed in feet per minute, and dividing this result by the desired number of revolutions per minute, or the desired speed of the ventilator, the outer circumference of the fan blades is obtained. No reference is made in the equation to the quantity of air in circulation, which is determined from the equivalent orifice of the mine and of the fan by the equation V — an * w hich V = volume of air (cu. ft. per sec.); a = equivalent orifice of the mine: o = the equivalent orifice of the fan. M. Murgue also uses the equation h = — — , and suggests that the value of K for any particular type of machine should be first decided, after which the tangential speed required to produce any given effective head of air column ( h ) is easily calculated from the formula u 4 Igh method The breadth of the blade is left largely to judgment, while this method of calculation gives the same size of fan for any given effective head desired, regardless of the quantity of air to be circulated, which is the same as saying that the ventilator will present the same efficiency when a large amount of air is crowded through its orifice of passage as when a smaller amount of air is necessary. Mr. Beard uses the following formulas for determining the several dimen- sions of a ventilating fan: m = a/_J \ nV V ' c + 163, 600 2 \ X 3 j Q n 2 i/ V 385,000,000 p (m 3 — l)n 2 K V^IV + i; D = e = m |/ 77Z 3 — 1 i/m 3 — 1 170 m 3,770 V p . n i/K*v' 4,'X 3 K* V 392 VENTILATION OF MINES. in which m = — , which is the ratio between the outer diameter of the fan a blades D and the inner diameter of the blade d , which equals the diameter of the intake orifice; b = width of fan blade; e = expansion of spiral casing at point of cut-olf. , . , . ,. . , The other symbols stand for the same quantities as previously indicated. Curvature of Blades.— It was at one time supposed that the curvature of the blades should be such that the radial passage of the air-current would be undisturbed by the revolution of the fan; but fans constructed on this principle gave no adequate results, and the theoretical spiral thus developed was entirely abandoned. A certain curvature of the blade backward, however, is assumed by many to increase the efficiency of the fan. This has not been proved in practice, but the effect of the backward curvature appears simply to necessitate a higher speed of revolution in the fan, in order to obtain the same results as are obtained with radial blades. The Guibal blade, radial at its outer extremity, or normal to the outer circumference, and curved forward in the direction of motion, atits inner extremity, so that the lip of the blade approaches tangency to the throat circle, seems the most effective blade in centrifugal ventilation. Tapered Blades.— The object of the taper is to produce a constant area of passage from the throat to the circumference of the fan, and thus prevent the reduction of the velocity of the current in its passage through the fan This feature presents an attempt similar to that attempted by the curvature of the blades, to hasten the passage of the air through the fan. It has not been proved, however, to have produced any beneficial result, except in the strengthening of the discharge pressure against the atmos. pheric pressure, in open-running fans. On the other hand, the slowing up of the air in its passage through a covered fan has by no means been proved a detriment, but is assumed by many to be an advantage, inasmuch as the air thus remains longer within the influence of the fan blades. The number of blades depends on the size of the fan. An increased number strengthens the fan’s action at the circumference, or supports the air at that point, and thus prevents the backlash or the reentry of air into the fan. due to the eddies occurring at the circumference when the blades are too iar apart. To a certain extent, the number of blades is modified by the speed of revolution, high-speed motors requiring a somewhat lesser number, while low-speed motors require more. In any case, the number of blades should not be so great as to abnormally increase the resistance to the air- current. In general, the distance upon the outer circumference from tip to tip of the fan blades should be from 2 to 3 times the depth of the blade. The spiral casing gradually reduces the velocity of the air and reduces the shock incident to the discharge of the air into the ati^sphere. The spiral casing should be so proportioned that the velocity of the flow from the fan blades will be maintained constant around the entire circumference, and this should not be less than the velocity of the blade tips. The expansion e of the casing at the cut-off should be such as to provide a velocity of the air at this point equal to the velocity of the blade tips, according to the equation e = -|-v. in which T> = diameter of fan; n = number revolu- 1 it Dnb tions per minute; b = breadth of fan blade. , . . The evase chimnev reduces the velocity of the air, as it is discharged into the atmosphere to The chimney should be sufficiently high to protect toe fan from the effect of high winds, but should not extend too far above the fan casing, the point of cut-off b ® i ^ 1 ® 1 ^ t ®ij Delow thlS ’ a about the level of a tangent to the throat circle at its lower side. High-Speed and Low-Speed Motors— The question of speed of the jrenti latin! motor is largely an open one, inasmuch as the same work maybe performed by a small ventilator running at a high speed as is performed by a large ventilator running at a low speed. . It is important to design a mine ventilator at a speed &™h for* his teen its being- increased in case of emergency. If the ventilator has oeen designed at a high speed, a demand for an increase of speed cannot be met as rladily as whin the ventilator is designed at a ^^m^ other words, the exigencies of mine ventilation demand that a ventilator shall be capable of greatly increased speed. Fan Tests.— A large number of fan tests have been made, from time t CONDUCTING AIR-CURRENTS. 393 time, on different types of fans and under different conditions, with respect to the resistance against which the fan is operated, and the quantity of air required, and the speed of the ventilator. The experiments have resulted, to a large extent, in tabulating a mass of contradictory data. The condi- tions that affect the yield of the centrifugal ventilator are so numerous, and the tabulation of the necessary data has been so often neglected m these experiments, as to render them practically useless for the purpose of scientific investigation. In conducting a reliable fan test, the following points should be observed: (1) Take the velocity, pressure, and temperature of the air at the same point in the airway, as nearly as practicable. This point should be selected near the foot of the downcast shaft, or m the fan drift at a suitable distance from the fan, to avoid oscillations of pressure and velocity. (2) The area of the fan drift should be uniform for a suitable distance in each direction from the point of observation, and tins area should be carefully measured. (3) Take the anemometer readings at differ- ent positions in the airway, so as to obtain an average reading over the entire sectional area. Do not interpose the body in this area so as to decrease the sectional area of the airway. (4) Take outside temperature of the air and the barometric pressure at the time of making the test. (5) The intake and discharge openings of the fan should be protected against wind pressure. (6) At least three observations should be made, at as many different speeds of the ventilator, and the number of revolutions of the fan carefully observed and recorded for each observation. . Mr. R. Van A. Norris (Trans. A. I. M. E., Yol. XX, page 637) gives the results of a large number of experiments performed upon different mine ventilating fans. This table, like all other tabulated fan tests, shows a large amount of contradictory data. The conclusions drawn by Mr. Norris from these tests are interesting and would be given here excepting that they might be misleading if considered apart from the description of the experi- ments and the discussion leading up to the conclusions. CONDUCTING AIR-CURRENTS. Doors.— A mine door is used for the purpose of deflecting the air-current from its course in one entry so as to cause it to traverse another entry, at the same time permitting the passage of mine cars through the first entry. The essential points in the construction of a mine door are that it shall be bung from a strong door frame in such a manner as to close with the current. The door should be hung so as to have a slight fall. If necessary, canvas flaps may be supplied to prevent leakage around the door, and particularly at the bottom. Double doors are used on main entries at the shaft bottom, or at any point where the opening of the door causes a stoppage of the entire cir- culation of the mine. Such doors should be placed a sufficient distance apart to allow an entire trip of mine cars to stand between them, so that one of the doors will always be closed while the other is open. Stoppings.— Stoppings are used to close break-throughs that have been made through two entries, or rooms, for the purpose of maintaining the cir- culation as the workings advance; also to close or seal off abandoned rooms or working places. Stoppings must be air-tight and substantially built. A good form of stopping is constructed by laying up a double wall of slate, having about 8 or 10 in. of space between the two walls. This space is filled, as the building progresses, with dirt taken from the roadways, or other fine material. In the building of stoppings to seal off* mine fires, it is important to begin the work at the end nearest the return air, and work toward the intake end, which should be sealed off last. This method avoids the danger of an explosion occurring within the workings that are being sealed off, as the necessary dilution of the gases within is accomplished by the fresh air- current, until the intake is finally sealed. Where the intake is sealed first, an explosion is almost inevitable, as has been proved in many instances. Air Bridges.— An air bridge is a bridge constructed for the passage of air across and over another airway, this being called an overcast; or, the cross- ing may be made to pass under the airway, this being called an unaercast. In almost every instance, overcasts are preferable to undercasts for several reasons. An undercast is liable to be filled with water accumulating from mine drainage; it is also liable to fill with heavy damps from the mine, when the ventilation is sluggish, and to offer considerable resistance to the free passage of the air-current. An undercast can never be maintained as air- tight as an overcast, on account of the continual travel through the 394 HOISTING AND HAULAGE. haulageway or passageway leading over it. This continual passing over the bridge causes a fine dust to sift into the airway and mingle with the air-current. All these objections are overcome in the construction of the overcast An air brattice is any partition erected in an airway for the purpose of deflecting the current. A thin board stopping is sometimes spoken of as a brattice; but the term applies more particularly to a thin board or canvas partition running the length of an entry or room and dividing it into two airways, so that the air will be obliged to pass up one side of the partition and return on the other side of the partition, thus sweeping the face of the heading or chamber. Such a temporary brattice is often constructed by nailing brattice cloth or heavy duck canvas to upright posts set from 4 to 6 ft. apart along one side of the entry a short distance from the rib. Curtains. — These are sometimes called canvas doors. Heavy duck, or canvas, is hung from the roof of the entry to divide the air or deflect a portion of it into another chamber or entry. Curtains are thus used very often previous to setting a permanent door frame. They are of much use in longwall work, or where there is a continued settlement of the roof, which would prevent the construction of a permanent door; also, in tempo- rary openings where a door is not required. HOISTING AND HAULAGE. HOISTING. There are two general systems of hoisting in use: (a) Hoisting without attempting to balance the load. In this system, the cage and its load are hoisted by an engine and lowered by gravity. (b) Hoisting in balance. In this system, the descending cage or a special counterbalance assists the engine to hoist the loaded ascending cage. Hoisting in balance is usually effected by the use of (1) double cylindrical drums; (2) flat ropes winding on reels; (3) conical drums; (4) the Koepe system; (5) the Whiting system 1. Double cylindrical drums are widely used: they consist essentially of an engine coupled directly or else geared to the common axis of the drums. The drums are usually provided with friction or positive clutches, and brakes, so that they can be run singly if desired, or the load can be lowered by gravity and the brake. , _ , , , 2. Flat ropes wound on reels are sometimes used either for unbalanced hoisting with a single reel or for balanced hoisting with a double reel. With & the double reels, the load on the engine is balanced throughout the entire hoist, for, as the rope is wound on the reel, the diameter of the reel is increased, and the lever arm through which the power of the engine is applied is also increased and the mechanical efficiency of the hoisting system de- creased. Thus, when the cage is at the bottom of the shaft and the entire weight of the rope is out, giving the maximum load to be hoisted, the drum is of a minimum diameter and the engine has, therefore, its greatest lever- age to start the load. A flat rope has the advantage of preventing fleeting, but its first cost, extra weight, wear, and difficulty of repairing have prevented its very general adoption. 3. Conical Drums— A conical drum, Fig. 1, equalizes the load on an engine just as a flat rope on a reel does. On account of the fleeting of the rope, however, the drum must be set at a considerable distance from the shaft to prevent the rope leaving the head-sheave. A tail-rope gives the most Fig. 1. HOISTING. 395 perfect counterbalance, the weight of the cage and rope on each side being exactly equal. 4. In the Koepe system. Fig. 2, one rope runs over and the other under driving sheaves S. A tail-rope R is used, and the head-sheaves x , x' are placed vertically and at such an angle to each other that their grooves and the groove in the dri- ving sheave are in line. As the main driving shaft is short, the en- gines can be placed close together, thus requiring a smaller foundation and engine house than for a drum hoist. The objection to the system is the liability of the rope to slipping about the driving sheave, and for this reason a hoisting indicator can- not be depended on. The system is also inconvenient for hoisting from different levels in the same shaft, and, in case of the rope breaking, both cages fall to the bottom. 5. The Whiting system, Fig. 3, uses two narrow- grooved drums placed tandem instead of a single- driving sheave as is used in the Koepe system. The rope passes from the cage A over a head-sheave, under the guide sheave T and around the sheaves if, F three times, then out to the fleet sheave C, back under another guide sheave, and up over another head-sheave to the cage B. The sheave M is driven by a motor either coupled direct to its shaft, or geared. The drums F and M are coupled together by a pair of connecting-rods, like the drivers of a locomotive, and this arrangement makes it possible to utilize all the friction of both drums to drive the rope. Thus a tail-rope is not depended on to produce more friction, though one is generally used as a balance to the loads. It is best to incline the follower sheave F from the vertical an amount Fig. 2. Q n equal in its diameter to the distance between the centers of two adjacent grooves, the object being to eliminate chafing between the ropes around the drums and to prevent them from running off by enabling the rope to run from each groove in one drum straight to the proper groove in the other. This throws the shaft and crankpins out of parallel with those of the main drum, but this difficulty is overcome by the connections in the ends of the parallel rods. The fleet sheave C is arranged to travel back- wards and forwards, as shown by the dotted lines, in order to change the working length of the rope, whereby hoisting can be done from different levels in the The power used for hoisting is generally steam for the main hoists, tricity is, however, coming rapidly into use, particularly for smaller shaft. Elec- hoists 396 HOISTING AND HAULAGE . and local Installations, and for main hoists in locations where fue* in- expensive and water-power available. Gasoline engines are also being used to an increasing degree, particularly for smaller hoists and in local installa- tions, and they are said to give very satisfactory results. PROBLEMS IN HOISTING. To Balance a Conical Dram.— Having given the diameter of one end of a conical drum, to determine the diameter of the other end that will equalize the load on the engines. In Fig. 1. call total load at bottom A, empty cage at top B, loaded cage at top C, empty cage plus rope at bottom!), small diameter of dram z, and large diameter y; then. Ax — By = Cy — Vx. Example.— In a shaft, the cage weighs 2 tons, the empty car 1 ton. the loaded car 3 tons, and the rope 2 tons. What should be the small diameter of a conical drum whose large diameter is 30 ft.? (2 + 2 + 3)x - (2 + 1)30 = (2 + 3)30 - (2+ 2 + l)z, or 7 x — 90 = loO — 5 z. 12z = 240, x = 20 ft. To Find the Size of the Hoisting Engine.— Let D = diameter of cylinder. P = mean effective steam pressure in cylinders, r = ratio of stroke to diam- eter of cylinder and i c = work per revolution required to be done: then, by making one cylinder capable of doing the work, n = number of strokes, u = work per minute (ft.-lb.). D = 1®^. or 2) = Example —What should be the size of the cylinders of a hoisting engine that is to perform 152.580 ft.-lb. of work per revolution, if the mean effective pressure is 45 lb. per sq. in. and the stroke of the piston is twice its diam eter ? D = = 23 - 5in ' To get up speed in a few seconds, more power than would be represented by the load to be lifted is required. Mr. Percy gives the following rule for t his case: In a properly balanced winding arrangement, with uniform load, multiplv the weight of coal in pounds by the average speed of the cage m feet per minute: add one-half to cover the frictional resistances, and call ihat the load. Then the power that must equal this must be the average effective pressure of steam in pounds per square inch on the piston, multi- plied by the area of one cylinder in square inches, and multiplied again by the average speed of the piston in feet per minute. Approximately, the average effective pressure of steam will be two-thirds of the pressure shown on the gauge near the engines. A good average piston speed is 400 ft. per minute. . , „ . _ _ , , n . , c . To Find the Actual Horsepower of an Engine for Hoisting Any Load Out of a Shaft at a Given Rate of Speed — To the weight of the loaded car add the weight of the rope and cage. This will give the gross weight. Then, H. P. gross weight in lb. X speed in ft. per minute . L ^ “ 33.000 contingencies, friction, etc. . , . , . , ^ ~ ^ Example. — H aving a shaft 600 ft. deep, gross weight of load 20,000 Id., to be hoisted in II minutes, what horsepower is required? H . p. _ = 243 H. P„ nearly . To which add £ for contingen- cies, and we have 324 H. P. . ^ _ ... , In a shaft with two hoistways, use the net weight -j- the weight of one rope, instead of the gross weight. . The following rules regarding winding engines are given by Percy: 1. To Find the Load That a Given Pair of Direct-Acting Engines Will Start. Multiply the area of one cylinder by the average pressure of the steam per square inch in the cylinder, and twice the length ot the stroke. Divide this by the circumference of the drum, and deduct i for friction, etc. HEAD-FRAMES. 397 Example.— Given a pair of engines, cylinders 20 in. diameter by 40 in. stroke, the drum 12 ft. diameter, and the pressure at steam gauge 50 lb., steam cut-off at average pressure of steam in cylinder 48.2 lb. Then, area of cylinder = 314.16 sq. in. 314.16 X 48.2 X 80 = 1,211,400.96. The circumference of the drum = 452.4 in. 1,211,400.96 -4- 452.4 = 2,677. f of 2,677 = 1,784 lb., or the net load. The gross load would include the weight of rope, cage, and car, but as these are balanced by the descending rope, cage, and car, the net load only is found. The drum mentioned is cylindrical. 2. Knowing the Load and the Diameter of a Cylindrical Drum, and the Length of Stroke, the Cut-ofF and Pressure of Steam at Steam Gauge, to Find the Area and Diameter of Cylinders of a Pair of Direct-Acting Engines. — Multiply the load by the circumference of the drum, and add one-half for friction, etc. Divide this by the mean average steam pressure, multiplied by twice the length of the stroke. Example. — Having the drum 10 ft. in diameter, the stroke 6 ft., the steam pressure at gauge 60 lb., the cut-off at £ of stroke, and the load 5 tons, or 11,1 Then’ 11,200 X 31.416 (circumference of drum) = 351,859. 351,859 + £ of 351,859 (or 175,930) = 527,789. , _ The mean average pressure = 56.2 lb. 56.2 X (6 X 2) = 674.4. 527,789 - 4 - 674.4 = 782.6 sq. in., area of piston. 782.6 .7854 = 996. V 996 — 31.56 in., or diameter of cylinder. 3 To Find the Approximate Period of Winding on a Cylindrical Drum With a Pair of Direct-Acting Engines.— Assume the piston to travel at an average velocity of 400 ft. per minute, and divide this by twice the length of the stroke, and multiply by the circumference of the drum. This gives the speed of cage in feet per minute. Divide the depth of shaft by this, and the result will be the period of winding. , „ ^ _ . _ . , Example. — Drum, 31.416 ft. circumference; stroke, 6 ft.; depth of shaft, 1 500 ft ’ Then, 400 - 4 - 12 = 33.33. 33.33 X 31.416 = 1,047.1. 1,500 -4- 1,047.1 = 1.43 min., or about 1 min. 26 sec. . „ _ A . , _ .. , 4. To Find the Useful Horsepower During a Winding. — Multiply the depth of shaft by net weight raised; divide this by number of minutes occupied in winding, and divide again by 33,000. . , _ . , Example. — Net weight, 2 tons = 4,4801b.; depth, 1,500 ft.; period of wmd- mg Then, m 4^0 e x 1,500 = 6,720,000. 6,720,000 - 4 - 1.43 = 4,699,301. 4,699,301 -4- 33,000 = 142+ H. P. HEAD-FRAMES. Head-frames are built of wood or steel, and some of the typical forms are shown on pages 275 and 276. They vary in height from 30 to 100 ft., depending on local conditions. , , „ _ . , , The inclined leg of a head-frame should be placed so as to take up the resultant strain due to the load hanging down the shaft and the pull of an engine. Fig. 4 shows the graphical method of determining the direction and mag- nitude of this resultant force. Produce the direction of the two portions of the rope lead- ing to the drum and down the shaft until they intersect at G, measure off a distance G K to scale to represent the load hanging down the shaft; similarly, measure off GH to the same scale to represent the pull of the engine, com- plete the parallelogram GHLK; the direction of the line G L represents the direction of the resultant force, and its length represents the amount of this force. The inclined leg of the head-frame should be placed as nearly as possible parallel to this resultant line, and should be designed to withstand a compressive strain equal to this resultant. _ . , .. Head-sheaves are made of iron, being sometimes entirely cast, or else tne Fig. a. ✓ 398 HOISTING AND HAULAGE. rim and hub are cast separately and wrought-iron spokes are used. The former are cheaper and quite satisfactory, but the latter are lighter and stronger, and therefore usually better. The diameter of the sheave depends on the diameter of the rope, and the table giving this will be found on page 120. The groove in the sheave should be wood-lined, to reduce wear on the rope. Wrought-iron spokes should be staggered in the hub and not placed radially. _ _ A A _ Guides and conductors are usually of timber rigidly attached to the sides of a shaft. In England and certain parts of Europe, wire ropes are used for guides and are strongly advocated, but they have never found favor in America. These ropes when used are weighted at the bottom, and Percy gives 1 ton for each 600 ft. in depth for each wire as a good weight to be used. When not thus weighted, the ropes are fastened at the bottom and attached to levers at the top, the levers being weighted to produce the requisite tension. Safety catches usually consist of a pair of toothed cams placed on either side of the cages and enclosing the guides. When the load is on the hoisting rope, these cams are kept away from the guides by suitable springs; but if the rope breaks, the springs come into action and throw the catcnes or dogs so that they grip the guides, and the tendency to fall increases the ^Detaching hooks are devices that automatically disconnect the rope from the cage in case of overwinding. HAULAGE. The magnitude of modern mines and the practice of loading or of treating the coal or ore at a large central station makes the underground haulage of the material one of the most important problems in connection with mining. A good haulage system is now essential to make most mines a commercial success. Haulage may be considered under the following heads: 1. Inclined Roads— Gravity planes, engine planes. , 2. Level Roads— Mule haulage, rope haulage (tail-rope and endless rope), motor haulage (steam, electricity, compressed air, or gasoline). Gravity Planes.— The loaded car or trip hauls the empty car up the grade. Two ropes are attached to a drum so that the rope attached to the loaded car unwinds from the drum as the car de- - scends, while the rope attached to the empty 4 ^ car is wound on the drum and the car thus — hauled up the plane. The natural slope of Horizontal. the ground, in a large measure, determines Fig. 5. the grade of the incline, but where it is pos- sible to alter the direction of the incline, the grade may be lessened by constructing the incline across the slope of the ground. The grade of the incline may be increased by carrying the upper landing forwards till a point is reached from which the required grade is obtained. „ A _ , The following rule gives suggestions based on practice that has been successful: For lengths not exceeding 500 ft., the minimum grade for the incline should be 5 $ when the weight of the descending load is 8,000 lb. and that of the ascending load 2,8001b. Or the inclination should not be less than 5 H if the respective descending and ascending loads are one-half of those just given. When the length of the plane is from 500 to 2,000 It., the grade should be increased from 5$ to 10$, according to the loads. A load of 4,000 lb. on a 10$ grade 2,000 ft. long will hoist a weight of 1,400 lb. The angle of inertia is that angle or inclination at which a car will start to move down the slope or plane. The car, when it has once started on this S rade, will continue to accelerate its speed as it descends the plane A B , ig. 5 . If we decrease the angle of inclination until the plane A B occupies the position A C, such that the moving car will continue to move, at a uniform velocity instead of accelerating its speed, the angle EGA will be the angle of rolling friction, and the tangent of this angle will be the coefficient of rolling friction for the car. . _ .. The upper portion of a plane is made steeper than the lower portion so that the trip may start quickly at the head and afterwards maintain a uniform velocity. With a good brake to control the cars, the uniform grade of a central portion of a gravity plane should not fall much below 3 , which corresponds practically to a 5£$ grade. HAULAGE. ^99 The acceleration f of the haulage system is given by the formula / = x g X sin a Pl + P2 where p, and p, are the descending and ascending pulls, respectively. The length of steep pitch is given by the formula- i = |L, to haul the loaded trip up, is T = ( W + w l) sin a + ( W + w l) cos a X /*> where IF = weight of loaded trip; wl = weight of rope; a = slope angle; ** "example 6 — 1 Mndthe°possible tension of a rope used to lower a loaded trip nf two cars upon a plane 800 ft. long, having a uniform grade of 5 + 2w ’] Example.— F ind the horsepower for an endless-rope system 5,000 ft. long for an output of 1,000 tons per day of 10 hours in a flat seam, the mine cars having a capacity of 2.000 lb. each and weighing 1,200 lb. each. Assuming a speed of winding of 8 miles per hour or 704 ft. per minute, and for the coefficient of friction /m = T = a [ 5,00 °^^ ( 1 + + 2 X 1-58 X 5,OOo] = 1,697, say 1,700 lb. H. P. = 704 5,000 40 X 33,000 [3,333 ( 2 X 1,200 \ + 2,000 X 1.58 X 704 J = 36.2 H. P. or, 36.2 assuming an efficiency for the engine of 60^,—^ = 60 H. P. Inclined Roads.— The calculation of power for inclined roads is the same as that just given, excepting that the work due to lifting the coal through a height h must be added to that found by the previous formulas. If h equals the elevation due to the grade of the incline, the additional work of the engine due to hoisting the load from this elevation will be OA and the total work per minute u will be u = fi i[o ^1 + + 2 w v J + O h. Example. — Assuming the same conditions as given above, and, in addi- tion, a rise or elevation of 100 ft. in the entire length of the haulage way, we hare u = ^[ 3 , 333(1 + 2 ^^°° ) + 2 X 1.58 X 70l] + 3,333 X 100 = 1,528,050 ft.-lb. per minute = 46.3 H. P., or assuming an efficiency of 60£ for the engine, ^ = 77 H. P. MOTOR HAULAGE. Locomotive Haulage. — Wire-rope haulage is very efficient in headings, on heavy grades, and against large loads, but in crooked passages it entails great costs for renewals and repairs. When the grades do not exceed 5£ for short distances and average 3# against, or for short distances 84 and 54 average in favor of loads, locomotives have been found the most economical form ot haulage. MOTOR HAULAGE. 403 M EK^'iSS® s““m l-omoaves are K^J3^S3!»^^"y5aa a?r and electricity of ^ whfchTnumber of types have been designed in recent yearf and whTch have been very successful and have shown a marked efficiency over the mule . _ 194 , compressed air is particularly auDlicable irf gaseolis mines, as it improves ventilation and is perfectly safe under all conditions. The great disadvantage in compressed-air haulage is ^M^H^MyeXof^he Baldwin Locomotive Works, gives the following in In 8 oMer th^co^pre^ed^locomotives may be able to make a fair lenffth° of run, the tanks for storage purposes must necessarily be rather cumbersome^ and constructed to carry high-storage pressures lnorder that theTmay be designed correctly and get a minimum of storage for the maximum work expected, it is necessary to have a complete profile of the nrnnosed haulage road and to make a tabulated statement of the air con Siwfon oSTe Various grades, noting the “ cut-off” necessary to produce the reamsite tractive effort. By making a summation of these varmus amounts, an^addtng^O^y we will have the possible amount of air used in doing cer- tai IMrLcesL e ry lfi therefore, to provide storage on the loepmotive for this amount of air at a much greater pressure than that used m the cylinders. Tn order that the locomotive may receive a quick charge at the stations specially provided for the purpose, it is necessary to have stationary storage to 800 lb and to have the volume of this storage at least double the tank capacity of the locomotives comprising the system. This allows an equalized nressure in the locomotive storage of approximately 600 lb. . . ^ The following formula is useful in determining the capacity of stationary storage: P' = in which V = volume of storage on locomotive; X = volume of stationary storage desired; p = cylinder pressure; P = stationary storage pressure; and if = locomotive storage P res ®^- . , If the average time for each trip is 30 minutes, the compressor must be able to compress in that time to pressure P, the calculated amount of air required for one trip or series of trips for the various locomotives included in the haulage. In general, it is customary to extend extra-strong pipeinto the mine and of such length and diameter as to bave the required volume for the stationary storage. There are times however when it would be found more economical to arrange for tank storage either inside or putsitm the mine, but in general, especially when the mine is advancing, it is the better practice to install pipe storage since it increases the range of the locomotive as the workings advance. . ^ ^ - The following table gives the various tractive efforts of different sizes of compressed-air locomotives, when working at 100 lb. cylinder pressure, and various cut-offs. If other pressures or strokes are used, the tractive efforts are directly proportionate. This table is calculated by means of the formula, tractive effort = d 2 lxP' D ’ in which d = diameter of cylinder; D = diameter of driver; Z = length of stroke; p — working pressure of the cylinders; and x — variable due to the various cut-offs. 404 HOISTING AND HAULAGE. Tractive Efforts of Compressed-Air Locomotives. Cylinder. Diam- eter of Driver. Inches. Weight on Driver. Pounds Tractive Effort for Each 100-Lb. Cylinder Pressure at Various Cut-Offs. Diam. Inches. Stroke. Inches. 7 e 3 3F 5. 8 ■ 1 * 3. 8 4 1 8 5 10 24 6,000 1,020 990 920 835 710 530 325 6 10 24 8,500 1,470 1,425 1,320 1,200 1,020 760 445 7 12 26 13,000 2,200 2,150 1,990 1,810 1,540 1,140 700 8 12 26 18,000 2,880 2,750 2,600 2,360 2,000 1,510 900 9 14 26 25,000 4,340 4,140 3,840 3,490 2,960 2,220 1,350 10 14 26 32,000 5,280 5,150 4,740 4,310 3,660 2,630 1,670 11 16 28 42,000 6,770 6,450 5,980 5,440 4,620 3,470 2,140 12 16 28 52,000 8,050 7,800 7,200 6,550 5,580 4,150 2,550 On account of certain losses due to radiation, etc. for cut-off at full length of stroke in steam practice, x is taken as .85. While cylinder surface acts as a detriment to the use of steam, it acts entirely opposite in the use of air, for the reason that, in the expansion of the air, very low temperatures are produced, and, with a maximum of cylinder surface exposed, we absorb a maximum of heat from the surrounding air, which virtually adds new energy to the air, thus acting as a reheater. Therefore in air practice, x is made .98 for full-stroke cut-off, with the others proportionately high. If simple-expansion cylinders are used, the working pressure should not exceed 130 lb., while, with compounds, one can easily use from 180 to 225 lb. with great economy. Where it is imperative to have a minimum- sized locomotive storage with a maximum run, this can be accomplished with compound locomotives. Originally, it was the custom to lag the cylin- ders as in steam practice, but now it is found advantageous to leave them bare and to corrugate both sides and ends so as to present a maximum surface to the surrounding atmosphere while running, thus absorbing new energy. Example.— It is desired to haul trips of 60 cars, empties weighing 2,000 lb. and loads 6,000 lb. each, over a track having the following profile, and with one charge of air. All grades are in favor of loads. (The following calcu- lations have been made with the slide rule.) Profile of Road. Grade. Distance. Grade. Distance. Grade. Distance. 1.3# 800 ft. 0.30# 700 ft. 2.4# 400 ft. 2.0# 600 ft. 1.77# 1,025 ft. 3.5# 425 ft. 1.3# 800 ft. 0.90# 300 ft. 1.2# 320 ft. The maximum grade being 3.5#, and the car friction in this case being 1 #, the total resistance when ascending a 3.5# grade due to cars is, hence, 3.5# -HI# = 4.5#. Since it is desired to haul 60-car trips, and all grades are in favor of loads, it is only necessary to provide a locomotive capable of hauling 60 empties weighing 120,000 lb. up the above-mentioned grade. The drawbar pull necessary to do this is 4.5# of 120,000 lb. = 5,400 lb. In general, it will require a locomotive having a weight on drivers of 5 times the tractive effort desired if steel tires are used, as is the practice in the con- struction of air locomotives, and 6 times the tractive effort if cast-iron chilled wheels are used, as is the practice in electric locomotives. We will there- fore assume the necessary weight of the locomotive to give the proper adhesion as 32,000 lb., and we calculate that the tractive effort necessary to haul itself up the 3.5# grade would be 3.5# + .5# = 4# (.5# covering the fric- tion of the locomotive on the level) of 32,000 lb., or 1,2801b., to which we add the necessary drawbar pull to haul the desired load, 1,280 + 5,400, and have a total tractive effort of 6,680, which is about the limit of a locomo live on dry rail with sand. MOTOR HAULAGE. 405 Bv consulting the table of tractive efforts of compressed-air locomotives, we see that, at 100 lb. working pressure, a 10" X 14", 26" driver. locomotive has a maximum tractive effort at £ cut-off, which is practically full stroke, of 5,280 lb., and by dividing - 5 T % 8 <£ into our necessary tractive effort, we find that the necessary working pressure would be about 130 lb. # On this basis, we then make up the following table in order to ascertain the necessary air consumption: Grade. Distance. Going in T.E. 1.3 800' 3,375 2.0 600' 4,450 3,375 1.3 800' 0.3 700' 1,830 1.77 1,025' 4,100 0.9 300' 2,750 2.4 400' 5,075 3.5 425' 6,760 1.2 320' 2,220 0.3 700' Coming 2,600 Strokes. 120 80 120 105 150 40 60 65 50 Cut-Off. Cu. In. Air Used. 126,000 176.000 126.000 55,125 315.000 42,000 157,500 239.000 52,500 110,000 20 l additional . 1,399,125 279,825 Total - 1,678,950 cu. m. This equals 975 cu. ft. at 130 lb. pressure used in hauling the required loads on a single round trip. Since we should return to the starting point with 130 lb. in the locomotive storage, it is evident that the volume of the tanks shall allow for the use of 975 cu. ft. in addition to 1 volume at 130 lb. Let V = volume of storage on locomotive; P' = pressure of storage on locomotive; p — working pressure; V' = volume at working pressure nec- essary to do the work required. _ ., „„„ Then the product of the volume of the locomotive storage by its pressure must equal the sum of the volume necessary to do the work required multiplied by the working pressure, and the locomotive storage volume by the working pressure, thus, p’v = pv + pv\ or,r= v przr p - 130 If P' = 650, then V = 975 X _ f 3 Q = 244 cu - ft - With one locomotive, making trips every 30 minutes, we must arrange for a compressor capable of compressing 975 cu. ft. at 130 lb. m this time, bince it is customary to rate compressors at their capacity in free air per minute, the above is equivalent to 975 X 130 = 288 cu. ft. free air per minute. 14.7 X 30 This must be compressed to 800 lb. in the compressor, and stored in stationary storage. If X is the volume of the stationary storage, pV+PX VAX * P' = P'-P or X = 244 X 650-130 800 — 650 = 846 cu. ft. “ r P-P" The length of the haulage is 5,370 ft., hence the cross-section of the pipe 846 necessary to furnish the requisite storage is = .157 sq. ft. From the following table, this would require a 5£" pipe, but for practical purposes it is possible that a 5" pipe would be selected. # Returning with loads, it is possible that there is only one grade that the trip will hare to be hauled. 406 HOISTING AND HAULAGE. Standard Steam and Extra-Strong Pipe Used for Compressed-Air Haulage Plants. Trade Diam- eter. In. Cu. Ft. in 1 Lineal Ft. Lineal Ft. Necessary to Make 1 Cu. Ft. Steam. Extra Strong. Trade Diam- eter. In. Thick- ness. Weight per Ft. Thick- ness. Weight per Ft. 2 .0218 45.41 .15 3.61 .22 5.02 2 2i .0341 29.32 .20 5.74 .28 7.67 2£ 3 .0491 20.36 .21 7.54 .30 10.20 3 3£ .0668 15.00 .22 9.00 .32 12.50 3£ 4 .0873 11.52 .23 10.70 .34 15.00 4 4£ .1105 9.05 .24 12.30 .35 17.60 4£ 5 .1364 7.33 .25 14.50 .37 20.50 5 5£ .1650 6.06 .26 16.40 .40 24.50 6 .1963 5.10 .28 18.80 .43 28.60 6 From the following table we see that it would require 2.88 X 32.5 — 93.6 H. P.; hence, we would be compelled to arrange for a boiler capacity of practically 100 H. P., provided we used a three-stage compressor, as is the general custom. Horsepower Necessary to Compress 100 Cu. Ft. of Free Air to Various Pressures and With Two-, Three-, and Four-Stage Compressors. Gauge Pres- sure. Horsepower Necessary. Gauge Pressure. Horsepower Necessary. Two- Stage. Three- Stage. Four- Stage. Two- Stage. Three- Stage. Four- Stage. 100 15.7 15.2 14.2 900 36.3 33.7 31.0 200 21.2 20.3 18.8 1,000 37.8 34.9 31.8 300 24.5 23.1 21.8 1,200 39.7 36.5 33.4 400 27.7 25.9 24.0 1,400 41.3 37.9 34.5 500 29.4 27.7 25.9 1,600 43.0 39.4 35.6 600 31.6 29.5 27.4 1,800 44.5 40.5 36.7 700 33.4 31.2 28.9 2,000 45.4 41.6 37.8 800 34.9 32.5 30.1 2,500 43.0 39.0 Electric Haulage.— Mr. H. K. Myers says in regard to mine haulage by electricity: In general, it costs from 6 to 10 cents per ton to deliver coal from face of workings to shaft, slope, or tipple, where the haul is 1 mile and the tracks approximately level; yet I know three mines that at present haul from parting with the trolley system, the miner delivering from face of room, making an average round trip of 9,000 ft., at a total cost of 1 cent per ton. These mines have never had a mule in them, and it would be almost an impossibility to introduce them, for the reason that the seam is of such thickness that the clearance between tie and roof is only about 4 ft. Since the advent of the electric-mining locomotive, there has been a change in the mine wagons universally used. Formerly it was customary to find as much as 60 lb. per ton car resistance on the level, while at present it is as low as 15 lb. . _ . . , . In dimensioning mining locomotives, it is customary to make the weight from 6 to 8 times the necessary tractive effort, dependent entirely on the nature of the work. If the work is constant and a maximum, then the weight will be only 6 times the torque of the motors, while if the work is intermittent with a short-time maximum tractive effort, then the factor will be 8. The weight of an electric locomotive running at a speed of 6 to MOTOR HAULAGE. 407 8 miles per hour with intermittent load may also be mM be 400 lb for each rated horsepower of the motor, and the weight should be Himes the rated drawbar pull, regardless of speed. For continuous work, these weights should be decreased 25/*. Drawbar Pull on Various Grades for Different Sized Locomotives. Horse- Weight. Grades. power. Level. 1/* 2 J 3/ 4/ 5 J 6/* 10 20 30 50 70 100 4.000 8.000 12,000 20,000 28,000 40,000 500 1,000 1.500 2.500 3.500 5,000 460 920 1,380 2,300 3,220 4,600 420 840 1,260 2,100 2,940 4,200 380 760 1,140 1,900 2,660 3,800 340 680 1,020 1,700 2,380 3,400 300 600 900 1,500 2,100 3,000 260 520 780 1,300 1,820 2,600 In mines it is found that the friction between wheel and rail is less than on the surface, due to dampness and powdered coal on the rail. The tractive efforts with chilled wheels is usually considered ¥ of the weight, lhe table on page 408 and diagram on page 409 give hauling capacities of locomotives in tons of 2,000 lb. . , . For maximum continuous work, it is necessary to have a grade such that the efforts to haul the same number of empty wagons as loaded are equal. With the car resistance considered 1/ and the loaded cars weigh- ing 3 times as much as the empties, this is found to be * of 1/. The most critical point in the designing of mining locomotives is to make the limiting dimensions a minimum. The demands for various dimensions are wonder- ful. The headings in mines are never of more generous proportions than really necessary, and all clearances a minimum. The minimum dimen^ons for mining locomotives are as small as 2 ft. for wheel base, 8 ft. for length over all, and 3 ft. width. Scarcely two orders carry the same dimensions, and it is impossible to have any kind of a standard. In consequence of this, it is necessary to have a great variety of motors suitable for gauges as nar- row as 18 in. and for wheels as small as 20 in. m diameter. With such a variety, it becomes possible to construct a locomotive weighing 40,000 lb. on 3' gauge, having the width over all 62 in., height 35 in., and length 12 ft. In construction, it is necessary to have the most modern form of motors and the most rigid mechanical construction. The motors now used are of the best possible construction and efficiency. They are of the slow-speed street-car type, 6 to 8 miles per hour winding, and range in size from 4 to 50 H. P. It is customary to use the rheostatic type of controller for mining locomotives, on account of its small dimensions and apparent efficiency for this class of work, but it is doubtless but a short time until a very compact form of series-parallel type will be devised. On account of the use of this rheostatic controller, it becomes necessary to Pro- vide for large diverter capacity, and since the locomotive is designed for the maximum tractive effort, it is hardly ever possible to run without resist- ance and, hence, a large amount of current must be dispeped with the consequent heating. If the motors are overloaded, they heat rapidly, this heating varying as the square of the current. A motor that has a rating of 40 amperes for regular work, if worked for 3 minutes at 100 amperes, should not be subjected to such a strain oftener than once in 18f minutes, as shown by the following equation: 402 x x = 3 X 100 2 ; x = 18£ minutes. Using the same problem given under compressed-air locomotives, in which the maximum tractive effort was 6,760 lb., we find from the table of drawbar pulls that a locomotive equipped with two 50 H. P. motors (equals 100 H. P.) will carry the load with an overload, these motors being rated for continuous work at approximately 32 amperes of 500 volts. Using the formula = which t — various times at which 408 HOISTING AND HAULAGE. various amounts a of current are used on the corresponding grades, 2 the summation of the items t a 2 calculated for each section or grade, and T = total time that should be taken for each trip, we calculate the following table: Grade. Dist. T. E. Time. Minutes. Amperes. to? 1.30 800 3,375 1.5 114 Empties. 19,600 2.00 600 4,450 1.1 134 19,900 1.30 800 3,375 1.5 114 19,600 .30 700 1,830 1.3 74 7,100 1.77 1,025 4,100 2.0 128 32,800 .90 300 2,750 .6 100 6,000 2.40 400 5,075 .8 148 17,300 3.50 425 6,760 .8 182 26,500 1.20 320 2,220 .6 86 4,400 .30 700 2,600 1.3 96 Loads. 13,900 167,100 = 2 t a 2 ^Jl6U00 = 64; 4 096 T = 167100; T = 4a By this means we can make 60-car trips every 40 minutes without injury to the motors, based upon a speed of 6 miles per hour. (See also page 215.) Speed of haulage depends on the system of haulage used and on the con- dition of the haulage road. The law in Pennsylvania provides for a speed of haulage not over 6 miles per hour, and this is the speed at which electric and Hauling Capacity of Electric Locomotives. Horsepower. Weight. Drawbar Pull on Level. Frictional Car Resistance per Ton on Level. Grades. Level. 1 Jo W 2{ m 3 jo 3 if 4 f 5 f 6 i 10 4,000 500 20 23 15 10 8 6.3 5.2 4.2 3.5 3.0 2.2 1.6 30 15 11 8.4 6.7 5.4 4.5 3.8 3.2 2.7 2.0 1.5 40 12 9 7 5.7 4.7 4.0 3.4 3.0 2.5 1.8 1.4 20 8,000 1,000 20 46 29 21 16 13 10.3 8.4 7.1 6.0 4.3 3.1 30 31 22 17 13 11 9 7.5 6.4 5.4 4.0 3.0 40 23 18 14 11 9.5 8 6.8 5.9 5.0 3.7 2.8 30 12,000 1,500 20 69 44 32 24 19 15 13 10.7 9.0 6.5 4.7 30 43 33 25 20 16 13 11 9.6 8.2 6.0 4.4 40 34 26 21 17 14 12 10 8.8 7.5 5.6 4.1 50 20,000 2,500 20 115 73 52 40 32 26 21 18 15 11 7.9 30 77 55 42 33 27 22 19 16 14 10 7.3 40 58 44 35 29 24 20 17 15 13 9.3 6.8 70 28,000 3,500 20 161 103 74 56 44 36 30 25 21 15 11 30 107 77 59 47 38 31 26 22 19 14 10 40 81 61 50 40 33 28 24 20 18 13 9.6 100 40,000 5,000 20 230 147 105 80 63 52 42 36 30 22 16 30 153 110 84 67 54 45 38 32 27 20 15 40 115 88 70 57 47 40 34 29 25 19 14 MOTOR HAULAGE. 409 compressed-air haulages are usually calculated and at which loaded trips are usually run. Empty trips are usually run at a slightly higher speed. The speed for tail-rope haulage is given by three prominent makers of such plants, as follows: (a) 600 to 700 ft. per minute; (6) 8 to 10 miles per hour; (c) 6 to 8 miles per hour. The speed for endless-rope haulage is given by the same makers as (a) 140 to 150 ft. per minute; (5) 1 to 2 miles per hour; (c) 150 to 200 ft. per minute. A slow speed for endless rope is to be preferred as being much more economical in the wear of the rope and cars, and many prefer a single- car system to a trip system, thus doing away with the trip rider By han- dling: the cars singly or even in trains of two and at a slow speed, the load can be picked up without any slippage of the rope through the grips; while if trains of from 12 to 25 cars are used, with the rope traveling 3 to 3* miles per hour, it is impossible to pick up the load without having the rope slip through the grip, thus heating the rope and cutting it. The slow-speed, single-car or small-train, system requires more cars, but this is counterbal- anced by the life of the cars and rope. Those that have tried both systems prefer the slow-speed small trip to the high-speed large trip. It has been found in general practice that the maximum pulling power of a mule as well as a locomotive is, approximately, one-fifth its weight, or, in other words, a locomotive will pull as much as the same weight of mules will pull, and at a speed about three times as great. ...... Cost of Haulage.— So much depends on local considerations that it is difficult to give costs of haulage that will be of service. Mule haulage has been given as costing, under different conditions, 5.74 cents and 7.92 cents per ton-mile, and in other locations 2.35 cents, 2.95 cents, and 7.15 cents per ton of coal hauled. „ . ... The Berwind-White Coal Mining Co., at Windber, Pa., uses 30 electric loco- motives at various mines, which average, approximately, 400 tons per day ol 9 hours, per locomotive, over an average haul of 2 miles for the round trip. The approximate cost for operating one of these locomotives, including the wages of motorman, trip rider, and proportion of power-house expense, is about $6.00 ner day, or cents per ton of coal haul per mile. If the total load, including weight of cars, is considered, it figures f of 1 cent per ton per mile. These figures do not, however, include grades, which is an important factor in equating costs per ton per mile. In these mines there are no mules 410 HOISTING AND HAULAGE. whatever, the locomotives distributing the empty cars to room partings, for the men to push to the face. If the haul is done between side tracks and under similar grade conditions, the same locomotives could easily handle 1,000 to 1,200 cars per day. . , , Mr. F. J. Platt, of Scranton, Pa., gives the following comparative costs of electric and mule haulage per ton of coal hauled and under approximately the same conditions in the same mine: Name of Mine. Mule Haulage. Cents. Electric Haulage. „ Cents. Green Ridge Colliery New York & Scranton Coal Co New York & Scranton Coal Co Mt. Pleasant Colliery Hillside Coal & Iron Co Hillside Coal & Iron Co 7.15 6.58 2.35 2.95 10.77 9.10 2.76 2.62 1.07 1.27 4.56 4.65 The following costs of electric haulage, per ton of material hauled, are given in the catalogue of the General Electric Co.: Name of Mine. Mule Haulage. Cents. Electric Haulage. Cents. Wythe Lead & Zinc Co Blossburg Coal Co. Cleveland-Cliffs Iron Co. (’94, ’95, ’96) 10 2.56 7.9 3.9, 4.5, 4.8 At Carbondale, Pa., compressed-air locomotives have hauled coal for 1 5 cents per ton-mile, at Mill Creek, Pa., for 3.77 cents per ton-mile, and at Glen Lyon, Pa., for 1.89 to 1.93 cents per ton-mile. THIRD-RAIL MINE LOCOMOTIVES. By W. L. Affelder* Traction locomotives have overcome practically every obstacle that has appeared in their path except that of grade. No conservative manufacturer will recommend a traction locomotive for a haulage in which the grade against the loaded trips exceeds 5 per cent., and the more conservative Diace 4 ner cent, as- the practical limit. A traction locomotive will work successfully on considerably steeper grades when the grades are short and all of a large trip will not be on the grade at the same time, but where a grade of over 4 per cent, is continuous over a considerable distance, some other svstem of mechanical haulage should be adopted. This fact led several companies into experimenting on electric haulage m which tractive force due to the weight of the locomotive would not be a factor, and in which friction and gravity alone would have to be overcome. In 1899, the Morgan Electric Machine Co. placed their first third- and-traction-rail locomotive, or so-called ‘‘sprocket locomoUve, in the Star City Ind., mine of the Harder & Hafer Co., of Chicago. This system, as developed, combines the flexibility of the trolley-traction system and the advantages of the wire-rope systems in surmounting grades Ihe ihndiaA is generally placed 5 inches to the right of the center of the track. There are three sizes of third rail— standard, heavy, and special, and the compo- nent parts of < spike^to^he* tie's, which are first trimmed, if necessary, to receive it. On this stringer are spiked, at intervals of about 18 inches, pme blocks E of nent parts of each are made in 16-foot lengths. The standard size will be described. A 6*"xH" white : pine bottom _stnnger^ r securely *See ‘Mines and Minerals,” March, 1904. THIRD-RAIL MINE LOCOMOTIVES. 410a sufficient thickness to bring the height of the completed fluid rail 4 inches above the height of the steel rails. Two tongitudinal pme strips D, each in. X 1£ in., are spiked to the blocks, leaving a H-m. slot between them. They are trimmed on top in such a way as to allow the iron track C , which is 4 in. wide and 1-in. thick, to be partially countersunk. This track con- sists of a flat bar of iron with lf-in. square holes punched through it at intervals of the same distance. It is made continuous by means of perforated fish plates J that are securely bolted to the ends of the two bars at _ a joint. Two pine strips DD, which are similar to strips I) except that they are trimmed on the lower side to cover the iron rail, are laid on the strips I) and fastened to them with 4-in. spikes. By means of an insulated c0 PPer cable, which is connected with the iron bar, the positive electric current is introduced into the third rail. The wooden portion of the rail acts both as a carrier of the iron bar or rack and as a medium for insulating it. The negative current is carried by the bonded steel rails. The locomotives are made in two standard sizes: one having an oU-id.r. motor and the other two motors of the same kind. On each of the two axles B are two track wheels H and one steel sprocket A with its accompanying gear. The track wheels are tight on the axles, but the sprocket and gear are loose, the sprocket being insulated both from the axle and from the gear by means of maple blocks, shown m solid black m the figure. The teeth of the two sprocket wheels, which are geared to run in unison, run in the slot between the two wooden strips D D and D of the 410b HOISTING AND HAULAGE. third rail and engage the iron rail C. In coming in contact with the charged iron rail, they take up the current, and through the agency of copper con- tact springs that rub against them, impart the current to the motor or motors. In revolving, the motor drives the sprockets, and as the construc- tion of the third rail is such as to ma k e it absolutely rigid, the movement of the sprockets in the perforated iron track produces motion of the locomo- tive. As all transmission of power is through the cut-steel gear-wheels, loss of power is entirely eliminated. The following advantages are claimed for this system: The full power of the third-rail locomotive — weighing only 6.000 lb.— is available at all times regardless of the grades, within limits, or slippery character of the track sur- face. The third rail can be extended easily and cheaply by the track layers as the regular track is extended. There is little liability of explosions being caused by the electric current, as the conductor is close to the floor; and from this* same line power can be taken off at any point to light the mine and to run machinery. No sand, trolley pole, or trolley wire are required: and men and animals are safe, as it is practically impossible for them to accidentally come in contact with the electric current. Also, heavy fells of roof will not injure the third rail. Moreover, in this system, only a com- paratively small weight has to be moved, thus saving in power and wear. A modification of the above-described system is manufactured by the Morgan Electric Machine Co., consisting of a combination of a complete trolley traction locomotive with the third-rail feature for use on grades. Gathering locomotives are used to take the cars from the rooms. They are similar in their general construction to the ordinary traction locomotive bnt are shorter and lower. In traveling along the entries the locomotive obtains its power by means of a regular trolley attachment, but when leaving an entrv to go into a room the trolley pole is fastened down and a flexible insulated cable is hooked npon the trolley wire and upon the track. The current returns through the bonded rails in rooms where steel rails are used, and when wooden rails are used in the rooms a double cable like that on a mining machine is used, one cable being attached to the trolley wire upon the entrv and the other to the ground wire or entry rail. The reel upon which the cable winds acts automatically to keep the cable taut in winding and unwinding. It is operated by chains and sprocket wheels or by friction plates. Several makes of gathering locomotives are now being operated successfully, both in anthracite and bituminous mines. MINE ROADS AND TRACKS. Underground or mine-ear tracks should be solidly laid on good sills, rest- ing on the solid floor of the mine. They should be well ballasted, and should have good clean gutters on the lower side of the entry, so that the rails mav be protected as much as possible from the action .of the mine water. Much of the following data, on mine roads is based on an article on Mine Roads.’’ by Mr. H. L. Auchnmty. “Mines and Minerals." March. 1900. " Grade.— The trades depend entirely on oirotimstanees. V.::. when possible, the grade should be in favor of the load, and should be at least 5 in. in 100 ft. to insure flow in the gutters alongside the track. On main roads, where wagons having a capaeitv of 15 to 2.5 tons are hauled by anim a l power, the grades should not exceed 14 to 24 in flavor of the loaded wagon. Such a rate of grade provides for an easy return haul of the empty trip without wearing out the stock, and likewise insures good drainage. With grades under 14, unless the ditches are kept perfectly clean, the drainage is apt to be sluggish, and then, in low places, we are sure to find a wet and muddy track, which is a great source of waste energy. . Where banting is done by locomotives, whether by compressed air or steam, the adverse grades should not be over 1.54 to 2.54 if it can possibly be avoided. When gradients are heavy, too great a percentage of the tractive power of the locomotive is consumed in drawing itself up the grade. Ties should be spaced about 2 ft. apart, center to center, m ak i n g 15 to a 30' rail. The rail should be well spiked to the ties with four spikes to each tie. the joint between two rails on one side of the track being located about midway between two joints on the opposite rail. Care should be taken in locating the spikes that they are not all in the center of the tie. thereby MINE ROADS AND TRACKS. 411 causing a tendency to split the same. It is best to place them each side of the center with two spikes between the rails, on one side, and the two spikes on the outside of the rail on the other side of the center of the tie. With tne spikes so located, there is no tendency totototo pp^oVtlfe tif Tte” outside and inside spike are on the same side of the center oi tne lie. lies having a 5 in. face and 4 in. deep hy 5£ ft. in length should be ordinary sizes of rail, i. e., 16 lb. to 20 lb., and, m general, the thickness should be sufficiently great that the spike does not pass e ^ re ^^|^?racks tie as then its holding power is greatly diminished. On haulage tracks where 35-lb. to 40-lb. rail is used, the ties should be at least 5 in. deep have a face of 6 in., the ties ordinarily used for lighter sizes of rails being entirely too thin for rails of this weight, as a larger spike than the ordinary 3 in. X I in. is required to securely hold the vails to place. The ends of the ties should be lined up along one side of the track, so that they are all the same (Stancl from the rail and, with each tie placed at right angles to the rail as it should be, we have a well-spaced, neat-looking track, which, when we!l tamped with the ballast, is perfectly solid. On curves, the ties should be laid so as to form radii of the curves of the track. , Rails.— The weight of rail to be chosen in any individual case depends entirely on the weight of wagons used, and the motive power. For wagons whose ^Lpacity is alout 1.5 tons, the weight of rail, when the motxve power is live stock should not be less than 16 lb. per yd., while for wagons having a capacity of 2 tons or over, a 20-lb. rail should be used. There is no economy in P using a very light rail, as the base is gradually eaten away by the mine water when it comes in contact with the metal, and m the case of a heav} section of rail it will be much longer before the rail becomes weakened. On main roads, where haulage machinery of one kind or another is used, the weight of rail for 2-ton wagons should be from 25 lb. to 35 lb. per yd., and on steep slopes as high as 40 lb. per yd. . ~ In the case of locomotive haulage, authorities claim that the weighty should be regulated by allowing 1 ton for each driver for each 10 lb. weight of rail per yd . Gaupe —The gauge of the track in coal mines should not be less than 30 in. nor more than 48 in. A mean between these two, or a gauge 42 in. is desirable, because it combines, to a certain extent, advantages claimed for the extremes. The advocates of broad gauges believe that the greater stability of the track and the consequent reduction ^ ^ulage expen- ses, the increased capacity of the broad-gauged mine cars » the reduction m the outlay for rolling stock, and for repairs to the same, more than equal the disadvantages of broad as compared to the narrow gauges. Advocates of the narrow gauges think that the ease of hauling around sharp curves, the reduction in cost of construction, and the use of mine cars with inside wheels, are advantages greater than those advanced bythe advocates of the broad gauges. An allowance about im should alwaysbe made between the wheel gauge and the track gauge. By so < *°iug, tne : resist ance to hauling is greatly overcome, and there is no binding of the wagons on the track, hence a less likelihood of having derailed wagons. With an average running wagon, there is a resistance of 15 to 20 lb. per ton tractive force on a level track, which would be equal to the resistance occasioned by a gmde of .75^ to H, and with wagons that bind on the track, this resistance is greatly increased. . f Curves should be of as large a radius as possible, and never if possible, of less radius than 25 ft. The resistance of curves is very considerable. - The less the radius of the curve, and the greater the length of thee urvedtrack occupied bythe trip, or train, the greater the resistance. The length of wheel bases of the cars, the condition of rolling stock and of the track and the rate of speed, all influence the resistance, and there is no formula that will apply to all cases. In practice on surface railroads, engineers compensate for curves on grades at the rate of ijh* ft. in each hundred feet for each degree of curvature, the grade being stated in feet per hundred. In mine work, this compensation is not made, as the gam will not pay for the labor that must necessarily be employed to do work m a thoroughly scientific manner. , Sharper curves can be used on narrow-gauge roads than on broad-gauge roads, because the difference in length of the inner and ^terrailsoncurves on the same degree is not quite so great, and also because the wheel bases of cars are less. The track should be spread about * in. on easy curves, and 412 HOISTIXG AND HAULAGE. on very short curves about 1 in., or as much as the tread of the wheels will permit’. A good rule is to widen the track ^ in. for each 2£° of curvature. Short and irregular curves are to be avoided whenever possible, as they increase the load and are destructive to rails and rolling stock. When a sharp curve is necessary, the rail should be bent to the right curvature by a portable rail bender, or by a jack and clamps. To Bend Rails to Proper Arc for Any Radius.— Rails are usually 30 ft. long, and the most convenient chord to use in bending mine rails is 10 ft. Then, having the radius and chord, we find the rise of middle ordinate by squaring the radius, and from it take the square of £ the chord. Extract the square root of the remainder and subtract it from the radius; the result will be the rise of the middle ordinate. Thus, having a radius of 30 ft. and a chord of 10 ft., the middle ordinate will be 30 — y'&E — 5-, or 0.42 ft. Rail Elevation.— In elevating rails on curves, consider whether the hauling is to be done bv a rope, or by a locomotive, or electric motor. For either of the latter, elevate the rail on the outside of the curve; but for the first, elevate the inner rail, since as the power is applied by a long flexible rope, there is alwavs a tendency for both rope and wagons to take the long chord of the curve as soon as the point of curve is reached. On slope haulages, operated bv a single rope, when the weight of the wagons traveling on the grade of the slope is sufficient to draw the rope off the hoisting drum, the rails on curves should be elevated on the outside, the effect then being similar to that of a locomotive, i. e.. the centrifugal force tends to throw the wagon to the outside of the track. In such cases, the elevation should be moderate so as not to interfere with the trip when drawn out again by the rope—the opposite effect being then experienced. On an 18° curve (319 ft. radius 1. an elevation of 2 in. or 3 in. in the outer rail, where the haulage was by slope rope, has never given any trouble in operating. In general, the elevation of rail necessary for different degrees of curvature for a 42" track gauge should be made in accordance with the following table: Table of Elevations. For outer rail of curves for a speed of 10 to 15 miles per hour and a gauge of track of 42 in. for locomotives; or for slope haulages where cars run down grade by gravity. Degree of Curve. Radius of Curve (Ft.). Elevation of Outer Rail (In.). Degree of Curve. Radius of Curve (Ft.). Elevation of Outer Rail (In.). 1 5,729.6 i I 10.0 573.7 H 2 2.864.9 12.0 478.3 3 1,910.1 5 T6 TS 15.0 383.1 if 4 1,432.7 18.0 319.6 in 5 1.146.3 T6 20.0 287.9 6 955.4 H 57.3 100.0 7 819.0 a 95.5 60.0 4£ 8 9 716.8 637.3 _ e l 114.6 50.0 4£ I No elevation should be over 4£ in., which would be equivalent to an elevation of 6 in. for standard track gauge of 4 ft. 9 in., the latter being con- sidered as the maximum for standard gauge. A ^ Rollers.— The rollers on level tracks should not be more than about 20 ft. apart to properly carry the rope, and on gravity slopes where the lower end of the slope gradually flattens off. the distance between rollers should not be more than 12 to 15* ft., as this spacing allows the trip of wagons to run much farther, by keeping the rope well off the ties, than if they are farther apart, thereby not supporting the rope, and causing a great amount of friction between the rope and the ties. With tracks in fair shape and rollers 12 to 15 ft. apart, the resistance, due to the rope in running empty wagons down grades varying from 3.8* to 6.2*, varied from 6* to 15* of the weight of ropes by actual trial. MINE ROADS AND TRACKS. 413 Switches.— The switch, or latch , most commonly used in mines is shown in Fig. 7. When the branch or siding is in constant use, an ordmar\ railway lrog is substituted for the bar b. The latches a, a : are wedge-shapeS .bars of iron (made as high as the rail) withan^ “nne^ldtoletoW^/a rod Fig. 7. attached to a lever so that they may both be moved at once from the side of the track, or by a person situated some distance away. This switch is made self- closing or automatic whenever it is necessary to run all the cars off at the branch (the switch then being used only to admit cars to the main track) by attaching the latches through a bar or lever to a metallic spring, a stick of some elastic wood, or a counter weight, to pull them back into a certain position whenever they have been pushed to one side or the other by the passage of a car -I ^ ^ n -t-i-tVl i oofi rtn c nf on the main track. Figs. 10, 11, 12, and 13 show some of the applications of these spring latches or automatic switches. , A modification of this switch is shown m Fig. 8, which represents a form of double switch. These latches are set by the drivers, who kick them over and drop a small square of plate iron between them to hold them m place This switch costs more than the other style and is better adapted to outside r0a The^ordinary movable rail switch in common use on all surface railways is sometimes used in mine roads. It is commonly used m slopes arranged as • shown by Fig. 12, to replace latches set by the car, and is also largely used in outside roads. For crossings, ordinary railway frogs and grade crossings are sometimes used, as is also a small turntable, which then answers two purposes. More frequently the plan shown in Fig. 9, in which four movable bars are thrown across the main track whenever the other road is to be used, is adopted. The subordinate road is built from li to 2 in. higher than the main road, to allow the bars to clear the main-track rails. . . , . Turnouts.— On gangways or headings used as mam haulage roads, turnouts should be constructed at convenient intervals to allow the loaded and emptv trips to pass. These turnouts should be long enough to accommodate from 5 or 6 up to 15 or 20 cars. The switches at each end may be made seli- acting so that the empty trip, coming in, is thrown on the turnout, and in running out on the main track at the otner end, the loaded cars open the switch, which immediately closes. As there is constant trouble with self-setting switches, either from small fragments of coal or slate clogging them up, or from insufficient power of the spring to move them, they are viewed with dis- favor by many mine managers, who do not care to use them under any conditions. Slope Bottoms.— At the foot of a slope, or at the landing on any lift, the gang- way is widened out to accommodate at least two tracks— one for the empty and one for the loaded cars. The empty track should be on the upper side of the gang- way, or that side nearer the floor of the seam, and the loaded track on that side of the gangway nearer the roof of the seam. An arrangement of tracks often used is shown in Fig. 10. At a distance of 40 IS SIlOWll 111 -Tig. -L V. Al/ Cl uioiauuv or 50 ft. above the gangway, the slope is widened out to accommodate the branch leading into the gangway loaded track. This branch descends with a gradually lessening inclination until nearly at the level of the gang- way it turns into the main loaded track. A short distance abov e the gangway , 414 HOISTING AND HAULAGE. a bridge or door is placed, which, when closed, forms a latch by which the empty cars are taken off the slope. The empty track is about 6 ft. higher than the loaded track, and is carried over it on a trestle. The illustration in Fig. 10 shows the plan as arranged for a single slope, or one side only of a slope taking the coal from both directions. When coal is being raised from this lift, the bridge is closed; the empty car comes down and is run off over the bridge; the car is unhooked from the rope, and the chain and hook attached to the rope are thrown down to the branch below on which a loaded car is standing; the loaded car is attached, the signal given, the car ascends to the main track on the slope, opening the switch— or the switch may be set each time by the bottom men, by a lever at the bottom of the branch. This plan can only be economically applied in thick seams, as the height necessary to allow one track to cross the other on a trestle cannot be obtained in seams of moderate thick- ness without taking down a large amount of top. A more simple plan, which dispenses with the bridge, is often used. The branch is laid off, as shown by Fig. 10, but, near the point where it enters the gangway, a switch opening into the empty track is placed. By this arrangement, the. tracks cannot be as well arranged for handling the cars by gravity as in the former plan, in which the empty cars when detached from the rope run by gravity into the empty siding, and the loaded cars descend by gravity around the curve to the foot of the branch, where they lie ready to be attached to the rope. When the pitch of the slope is so steep that the coal or ore falls out of the cars, during hoisting a gunboat is used or the cars are raised on a slope carriage — in either case, the arrangement of the tracks ^at lift landings is entirely different. With either a gunboat or a slope carriage, the arrangement of tracks on the slope is the same; but, in the former case, a connection between the slope and gangway tracks is often advisable. When a , . , ™ gunboat is used, the gangway tracks run direct to the slope, and a tipple, or dump, is placed on each side to dump the mine cars f but when the cars are raised on a slope carriage, the gangway tracks run direct (at right angles) to the slope, to carry the car to the cage or carriage. The fl 9 or of the cage is horizontal, and has a track on it that tits on the end of the gangway track when the car- riage is at the bottom, and this track is arranged with stops similar to those on cages used in shafts. Another common arrangement of tracks at the bottom of a slope is shown in Fig. 11. A branch is made by widening the slope out near the bottom, and this, being a few feet higher than the main track, is used to run off the empties by gravity. The loaded cars run in by gravity around the curve to the foot of the slope in position to be attached to the rope. In ascending, the loaded car forces its way Fig. 12. through the switch, or the switch may be set by a lever located at the foot of the slope. When the empty car descends, it runs in on the branch, where the chain is unhooked and thrown over in front of the loaded car, and runs around the curve into ll^olSSved that in this plan the loaded car (and consequently the Fig. 11. the MINE ROADS AND TRACKS. 415 bottom men) stands on the track in line with the slope, and is in danger from any objects falling down the slope, or from the breakage of the rope or coup- lings; but this can be obviated by making the bottom on the curve. The illustration in Fig. 11 shows only one side of the slope; the other side is, of course, similar. All these plans necessitate the location of that part of the gangway near the slope, in the upper benches of the coal or near the top rock. The gang- way is then curved gently around toward the floor, so that, when it has been driven far enough to leave a sufficiently thick pillar, the bottom bench is reached and the gangway is then driven along the bottom rock. A very different bottom arrangement is shown by Fig. 12, which also represents a plan frequently adopted on surface planes. The two slope tracks are merged into one a short distance from the bottom of the slope, and on the opposite sides of the bottom two tracks curve around into the gang- way on opposite sides of the slope. As these branches curve into the main gangway tracks, a switch sends off a side track for the empty cars. The switch on the slope is either set by the car— and this can be done because the next loaded goes up on the same side on which the last empty descended —or by a lever located at the bottom. . . It will at once be seen that in this plan no opportunity is afforded oi handling the cars by gravity. The curved branches are made nearly level, and the momentum of the descending car, if quickly detached, is often sufficient to carry it partly or wholly around the curve, even against a slight adverse grade. The disadvantage above noted of having the bottom in direct line with the slope (where there is danger from breakage and falling material) also obtains in this plan. In the plan shown by Fig. 13, the grades may be so arranged that the cars can be entirely handled by gravity. The latches on the main-slope track may be closed automatically by a spring or weight, the loaded car running through them in its ascent on the slope, or both sets may be operated by a single lever at the bottom. The switch at the upper end of the central track (loaded) is set by a hand lever. All three sets may be linked together, so that they can all be properly set by a single lever. Reference to Fig. 11 will show that this is only a modification of that method. It requires space at the bottom for only three tracks, while Fig. 13 requires width to accom- modate four tracks, and is objectionable because it is more complicated. The extra set of latches at the top of the central track, and the curvature of both main tracks into this central one, must inevitably cause much trouble and delay from cars jumping the track at this point. The plan shown in Fig. 14 is open to many of the objections pertaining to some of those already described, and which need not be reiterated here. It can only be employed in thick seams, or in seams of moderate thickness lving at a slight angle or dip. In planning the arrangement of tracks on a slope, it is advisable to place as few switches as possible on the slope itself, to keep the main track Fig. 13. Fig. 14. 416 HOISTING AND HAULAGE. 'ESEzZEB a LOADED*—: unbroken, to make the tracks as straight as possible, to have nothing stand- ing at the bottom in direct line with the slope tracks, and to arrange the tracks so that cars are handled by gravity. . , The arrangement of tracks near the top of the slope, and on the surface, is often very similar to the bottom arrangements, as already described; but as all loaded cars (except rock and slate cars, which are run off on a separate switch) are to be sent off on one track, and all the empties come in on the same track to the head of the slope, and as there is usually abundance of room for tracks and sidings, these top arrangements are, in a measure, much more easily designed. In some instances, the two mam-slope tracks run into a single track near the head of the slope— a plan somewhat similar to the bottom arrangement shown by Fig. 12— and the cars are then brought to the surface on one track, which, after passing the knuckle, bifurcates into a loaded and empty track. A similar arrangement is frequently adopted at slopes on which a carriage or gunboat is used. When the two mam-slope tracks are continued up over the knuckle to the surface— the most common and best plan— the arrangement of tracks and switches may be planned entirely with a view to the quickest and most economical method of handling the cars. „ , _ . Vertical Curves.— The vertical curves at the knuckle and bottom of a slope or plane should have a sufficiently large radius, so that when passing over them the car will rest on the rail with both front and back wheels. The wheel base of the car must be considered in adopting the radius for these curves, for if the curve is of too short a radius, there is danger of the car jumping the track every time it passes over the curve. Tracks for Bottom of Shaft.— Fig. 15 shows the arrangement of tracks at the foot of a shaft, with one of the cages at surface. The grades should be so arranged that from the inside latches of the crossings the empty track should have a slight down grade from the shaft, and the loaded track a slight down grade toward the shaft. The cross- __ y __ ings and the short straight piece of road close to the shaft should be level. “=* As it is often desired to move empty Fig. 15. cars from one side of the shaft to the other, without stopping the hoisting, a narrow branch road should be cut through the shaft pillar, and used for this purpose. Where the pitch of the seam prevents this, a road should be laid alongside the shaft, room to accommodate it being cut out of the rock on the side most desirable. (See also Shaft Bottom, page 276.) _ _ „ , In arranging tracks for shaft bottoms, at tops and bottoms of slopes, on coal bins, for mechanical-haulage landings, at foot of slopes or shafts, or m the body of the mine, it is customary to provide double tracks of sufficient length to hold the requisite number of wagons for economically operating the plant and with sufficient distance from center to center of tracks, and from centers of tracks to sides of entries, to easily pass around the wagons where it may be necessary, either in handling them, or in lubricating the wheels. For wagons with a capacity of from 1£ to 2 tons, it generally requires an entry to be about 15 to 17 ft. wide in the clear for ordinary land- ings in the body ’of the mine, while at shaft bottoms the necessary width may attain 17 to 18 ft. in the clear, owing largely to location and local requirements. The curved crossovers connecting the tracks at shaft bot- toms should be designed with radii of as great length as can be introduced, thereby giving an easy running track. They should not be less than from 20 to 50 ft. on center lines for ordinary gauge of tracks, i. e., 36 to 44 in. On landings constructed in the body of the mine for the reception ot empty and full wagons handled by mechanical haulage from shaft or slope, and from this point transported by animal power to the various working places in the mine, a grade of about 1 f> in favor of the loaded wagons to be handled by the stock will be found quite an assistance in delivering the wagons to the haulage. The frogs and switches for these landings, as well as those required at the shaft or slope, should be formed of regular track rails, and can generally be arranged to be thrown by a spring or a con- veniently located hand lever, as has been described, instead of being kicked to position, as was the custom at one time. Besides these usual arrangements of shaft-bottom landings, at many plants the natural grades of the entries can be taken advantage of in designing convenient and economical methods for handling the mine cars. MINE ROADS AND TRACKS. 417 For instance, where the coal is to be hauled from the dip workings of a mine by some form of mechanical haulage, and a summit can conveniently be arranged for in the track on the same side of the hoisting shaft, at the proper distance therefrom, to accommodate the requisite number of loaded wagons to be hauled, thus allowing them to run by gravity over, say, a 1 > . O H Inches. Lb. Lb. 3X li Laboratory 40 100 6 X 2 One 560 1,200 10 X 4 Three 1,800 4,900 10 X 7 Five 3,800 8,000 15 X 9 Eight 7,400 15,500 15X10 Nine 7,800 16,000 20 X 6 Ten 5,300 11,200 20 X 10 Ten 8,100 18,300 12X30 Sixteen 14,200 33,000 15X30 Twenty 14,200 35,000 Extreme Dimensions. Length. Breadth. Ft. In. 1 10 0 1 6 6 3 10 10 10 Height. Ft. In. Ft. In. 6 1 3 9 0 5 11 9 4 4 0 10 2 3 9 5 11 11 6 11 4 4 250 250 250 250 250 250 250 250 250 250 s-< . ^ ft 0 a> g © H 4 6 8 15 15 15 20 30 30 and preparing it for other crushers, or for breaking large quantities of any material where an approximate sizing is not essential. The Dodge crusher, Fig. 2, has a fixed jaw a and a movable jaw b, operated by a cam on the shaft g. The movable jaw is pivoted at the bottom, so that the minimum movement between the jaws is at the discharge opening. The advantage of this is that the least movement occurs at the discharge opening, 420 ORE DRESSING AND PREPARATION OF COAL. and hence the product is of a fairly uniform size, so that the crusher may be used as a rough sizing apparatus. The disadvantages are that the large pieces of rock have to be crushed in the upper part of the space ^ between the jaws, where the motion is greatest and the pur- chase or leverage least, thus re- quiring an excessive amount of power, especially when dealing with hard material. The move- ment of the jaw at the discharge opening is so much less than that above that there is danger of clogging or blocking the ma- chine, especially when working upon tough or sticky material. The capacity of the Dodge style , , , of machine is less than that of the Blake. It is used largely as a secondary crusher, or for crushing comparatively small amounts of material where an approximately sized product is desired. Fig. 2. The Dodge Crusher. No. Size of Jaw Opening. Diameter of Pulleys. Width of Belt Used. Horsepower Required. No. Tons per Hour, Nut Size. Revolutions per Minute. Weight Complete. Inches. Inches. Inches. • 1 4 X 6 20 4 2 to 4 i to 1 275 1,200 2 7 X 9 24 5 4 to 8 1 to 3 235 4,300 3 8X12 30 6 8 to 12 2 to 5 220 5,600 4 10X16 36 8 12 to 18 5 to 8 200 12,000 Roll* Jaw Crushers.— Fig. 3 is a sectional view of a Sturtevant roll-jaw crusher. The rolling motion of the jaw subjects the material to a rolling and squeezing action, instead of a direct squeeze. The product of this crusher is approximately sized and there is no greater producer of sized output. The adjustment of the machine for fine crushing neces- sarily contracts the space for dis- charge, and thereby lessens its capacity. When set wide, or for material from 1 to H inches in size, the discharge is very free and the capacity is claimed to be greater than that of any other jaw and toggle machine. Gyratory Crushers.— These crush- ers, Fig. 4, are all large capacity, con- tinuous-action crushers, a is a ring or hopper against which the material is crushed by a conical head c, which Fig. 3. fits on a shaft g, the bottom of which is placed in an eccentric bearing so that the amount of space between a and c varies as the head rotates. The material to be crushed is dumped into the receiving hopper h, and the machine is thus automatically fed. ROLLS. 421 The advantages of this style are that the large pieces of material are received at the top of the jaws, where the motion is least and the leverage or purchase greatest, thus reducing the work necessary m this heavy y preliminary crushing. The relative move- ment between the crushing members is a maximum at the discharge opening, but the amount of this movement is so small that the product is approximately sized. The fact that the maximum movement is at the point of discharge assures a free discharge. There is practically no shaking imparted to the building by gyratory crushers. Their capacity is very great, and with a large size, material may be dumped into the hopper h directly from the cars. For small capacity a gyratory crusher is more expensive than a jaw crusher. Frequently, where very great amounts of material are to be crushed, large gyra- tory crushers are used as secondary crush- ers after jaw crushers of the Blake pattern, the discharge from the jaw crushers ran- ging from 6" to 12" cubes, and that from the gyratory crushers from 1£" to 2£" cubes. (See table on page 422). ROLLS. Cracking Rolls.— This is a general name applied to rolls having teeth, which are usually made separate and inserted. These rolls, Fig. 5, are employed for Fig 4 breaking coal, phosphate rock, etc., the object being to break the material into angular pieces with the smallest possible production of very fine material. The principal field for cracking rolls is in the preparation of anthracite coal, and the exact style or design of the roll depends largely on the physical condition of the coal under treatment. In most cases, the rolls are constructed with an iron cylinder having steel teeth inserted, the size, spacing, and form of the teeth depending on the size and physical condition of the material to be broken. Cracking rolls vary from 12 to 48 in. in diameter and from 24 to 36 in. in face width. The teeth of the larger sizes are from 3 to 3| in. high, and of the smaller 1 in. or less. The average practice in the anthracite regions of Pennsylvania is to give the points of the teeth a speed of about 1,000 ft. per minute, though the speed in different cases varies from 750 to 1,200 ft. per minute. One of the largest anthracite companies has a standard roll speed of 97.5 R. P. M. for the main rolls and 124.5 R. P. M. for the pony rolls. The harder the coal, the faster the rolls , can be run. If run slow and overcrowded, the rolls will make more culm than when driven at a proper speed. One advantage of comparatively fast driven rolls is that the higher speed has a tendency to free the rolls by throwing out, by centrifugal force, any material lodged between the (®) (g) 1*1 O© tIt- 1§J: |o© -~r§T nx ' oo r§r T§I OO in si Fig. 5. 422 ORE DRESSING AND PREPARATION OF COAL . teeth. In one test it was found that less fine coal was produced at 800 ft. per minute, but that the rolls blocked at this speed and hence had to be driven 1,000 ft. per minute. In one case a pair of main rolls 24 in. in diameter, 30 in. face, running at 1,000 ft. per min- ute, handled 2,500 tons of coal in 24 hours. A pair of 19" X 24'' main rolls run at 1,000 ft. per minute handled 300 tons mine run in 10 hours. A well-known maker of rolls for crushing bitumi- nous coal gives a speed of 100 to 150 li. P. M., according to the output re- quired, for rolls 24 in. in diameter and 33 in. long. As a rule, cracking rolls are never run up to their full capacity, as is the case with crushing rolls. The form of the teeth varies greatly, but, as a rule, the larger rolls have straight pointed teeth of the spar- row-bill or s o m e similar form, Fig. 6 a. The old curved, or hawk-billed, teeth, Fig. 6 b, have now gone almost wholly out of use. On* small sized rolls, rectangular teeth with a height equal to one side of the square base are frequently em- ployed, and these may be cast in seg- ments of manga- nese or chrome steel. Corrugated rolls have teeth or cor- rugations extend- ing their entire length. They were first introduced by a s x P « O > C3 < H o S ® a ◄ o a s E-* a o « a £ o Q a S3 % a « a z ◄ © c 'tire ; Sv C r-i CC CC Cl o rl ^ x in c c c c c c n Cl CC tC OC t- © f-, © ©, ft cog- * 5 ft KXNCrrdXCC O ! r-M'TTfLOt'XO O Cl £1 CC 'C © . g 4 © « © °s © © >» OD •omBij jo qjSna'i X 2 I ’© . •aurej^j jo qiptAi 1>0»— I Cl OC •'S’ CC CC -S' ® 1— iCCCCCC^iOlCt-OC® •jaddon i dox oi araBi^T mono# j uioj^ jqSian TfOiSHiC C-J iO OiOn^O •^annd sutAua jo suoitnioAon; J COCOiCOCOOO i OCMCMCMCCO |>-lC'H*'^''^ , ' , ?‘CCCCCCCC «** o .S-P © OQ © <— Face. S n ” s © | | ft 1 5 1 r- Cl Cl -S CC CC 'S* TT tT 1 1 -aio JO qooq; jo laaoujBqo 1 oj SutpiooDY k ^utH -ui J SutssBX 4 qT 000 6 jo suox j tit ‘juoh JOd AqondBO 2 to 4 4 to 8 (ito 12 10 to 20 15 to 30 25 to 40 30 to 60 50 to 125 100 to 160 Weight of Breaker. Pounds. SiSSSSSSoS locflcxxcqox^ c^ior^cc'i-tooic’ci' jnoqy ‘poutq -moo sSutuado ^nt -Ataoan ooJtlX J° ' suotsuamid Inches. 1 r-> CC SC ■'3* Tf O CO t> a r-i xxxxxxxxxx d lO CC l> oc o ^ 3C jnoqy oc © ft ‘Suraado Stn xxxxxxxxxx -ApoaH qoB 3 jo © c ’suotsuatma >— t hhhh *9Ztg ROLLS. 423 Fig Mr E. B. Coxe, at Drifton, Pa M but they have not come into general use owing to the fact that, while they break some coal fairly well, in most cases it has been found that a continuous edge causes too much disinte- gration along its length, while a point splits the coal into three or four pieces only, all the cracks radiating from the place where the point strikes, thus producing very much less culm. Another advantage possessed by the toothed rolls is that if anything hard passes through the corrugated roll and breaks out a piece of the corrugation, the entire roll is ruined, while, in the case of the toothed rolls, any one of the teeth may be replaced. Disintegrating rolls and pulverizers are sometimes used to reduce coking coal to the size of corn or rice before intro- ducing it into the ovens. One roll is driven at double the speed of the other, the slower roll acting as a feed-roll, and the other as a disintegrator. The slower roll is commonly driven at from 1,800 to 2,000 ft. per minute peripheral speed, and the faster roll at from 3,600 to 4,000 ft. per mi- nute. The teeth are always fine, rarely being over f m. high. In some cases, the inner roll is provided with a series of saw teeth from £ in. to | in. high and having about f in. pitch, the individual teeth being set so as to form a slight spiral about the body of the roll. The other roll is provided with teeth having their greatest dimension in the direction of rotation, so that they tend to cross the teeth on the opposite roll. These teeth are also set so as to form a slight spiral, and thus prevent blocking. In other cases, the teeth on both rolls are set in the form of quite a steep spiral. , _ . , , Hammers— For the reduction of coal, crushers employing hammers have been used, Fig. 7. The crushing chamber is usually of a circular or barrel form, and the crushing is done by means of hammers pivoted about a central shaft. These swing out by centrifugal force and strike blows upon the coal to be broken. When it is reduced sufficiently fine, it is discharged through bars or gratings at the lower portion of the machine. This style of machinery is usually employed in preparing coal for coke ovens, thus occupying the same J field as the disintegrating rolls. A No. 3 pulverizer of this type will crush 50 to 75 tons per hour run of mine, down to £ in., or it will crush 100 tons per hour of slack. Such a machine occupies about 8 sq. ft. of floor space and requires 25 to 30 H. P. to run it. Crushing Rolls.— The prin- cipal representative of this type of machine is the ordi- nary Cornish roll having a fairly wide face and rather small diameter. The diam- eter of these rolls was kept down for a great many years on account of the fact that the chilled cast-iron shells could not be obtained in large sizes and were expen- sive and hard to handle. With the advent of the rolled- steel shells, it became possible to employ larger diameters and higher speeds. Rolls of the Cornish type vary from 4" face and 9" diameter to 16" face and 42" diameter. The distinctive feature of the Cornish roll is a comparatively wide face compared with the diameter, and a rather slow peripheral speed. Many of the modern Cornish rolls are provided with rolled-steel shells, especially when employed for very fine crushing, owing to the fact that these shells are of a more uniform texture, work more evenly, can be worn much thinner before being discarded, and can be trued up with less difficulty than is the case when chilled iron is employed. To guard against the bending of the rou Fig. 7. 424 ORE DRESSING AND PREPARATION OF COAL. shaft or breaking of the machine in case any hard material (such as a pick or hammer) gets between the rolls, one roll is mounted in a movable bearing and kept in place by a compressed spring washer. This washer is composed of two plates between which are placed one or more steel springs. The plates are kept together by several small bolts, which are screwed up so as to compress the springs to a certain degree. Then the entire arrangement is employed as a washer on the rod that keeps the rolls together. Should the pressure exerted on the rolls exceed that already exerted in the spring, the plates would be brought nearer together and the roll allowed to move back and pass the hard substance, but at any pressure below this, the roll acts as if placed in a fixed bearing. Cracking, corrugated, and disintegrating rolls are usually provided with breaking pieces back of one of the rolls, so that in case any extra hard piece passes through the rolls, the breaking piece will give way, allowing the rolls to move back and thus prevent the bending of the shaft or breaking of the machine itself. Compressed spring washers have never come into general use in connection with this style of machinery. Amount Crushed.— The amount of material that can pass between any pair of rolls is proportionate to the number of square feet of roll surface passing per minute; hence, the capacity may be increased by keeping the face width the same and in- creasing the speed, or the same capacity may be obtained by reducing the face and increasing the speed. According to Stutz (A. I. M. E. IX, page 464), if the distance between the contact points of the material with the rolls be t, Fig. 8, the dis- tance between the crushing face of the rolls w, the angle a, as shown in the figure, and R the radius of the roll, then 22 _ t — w _ t — w ~ 2 vers, sin a ~~ 2(1 — cos a)’ According to Pernolet, the amount of material that may be crushed by a pair of rolls in a given time is equal to one-fourth or one-fifth of a band or layer whose length is the circumference of the roll multiplied by the number of revolutions; whose width is the length of the rolls, and whose thickness is equal to the space or distance between the rolls. 1 1 \ Fig. 8. Or, Q = dnnlw , where d = diameter of rolls; ir = 3.14; n = number of revo- lutions in the given time: l = length of rolls; w = space between rolls; and £ = coefficient, to allow for the irregular feeding of the material and the space between the pieces. . _ _ The Denver Engineering Works gives the following formulas for the capacity of crushing rolls: T = tons per hour; R = rev. per min.; S = mesh (inches). For 14" X 27" rolls, T = 7.725 R S. For 16" X 36" rolls, T = 11.775 RS. For 12" X 20" rolls, T = 4.9 R S. Speeds. — The pressure on the bearings necessary to crush ore depends directly on the face width, and hence if the capacity can be kept the same and the face width decreased, it is evident that there will be less pressure on the bearings and less loss in friction. The difficulty of keeping the bearings cool when crushing hard rock with the old Cornish rolls has led to the adoption of high-speed, narrow-faced rolls for certain classes of work. One objection to running the small diameter rolls fast is that the larger pieces of ore have a tendency to dance on the face of the rolls rather than to be crushed, while the bite is better when the speed is slower. The advantages of high-speed, narrow-faced rolls are: greater capacity for a given bearing pressure; less loss of power from friction; less dancing of the ore on the roll face, owing to the fact that the angle of approach between the surfaces of large rolls is more acute than with rolls of a small diameter. High-speed, large-diameter rolls will handle C 9 arser material and hence make a greater range of reduction than small-diameter rolls. The disadvantage of high-speed rolls is that they tend to hammer and pulverize the ore, so that with verv brittle minerals a high speed may be detrimental. In general, it may be stated that for crushing to any definite size with the lowest possible production of very fine material, rolls are the best form of ROLLS. 425 machinery on the market. For fine crushing of brittle material, quite slow speeds may give the best results. . , . ,. ,, The accompanying table gives some facts m regard to the crushing-roll practice of several manufacturers, the data having been taken from their catalogues or other information furnished by them. Crushing Rolls. Name. Size. Inches. Peripheral Speed in Ft. per Min. Spring Pres- sure in Lb. per In. of Face Width. Character of Rolls. Frazer & Chalmers... 24X8 36X16 600-1,500 4,000 for hard quartz. Cornish. Frazer & Chalmers,.. 44X5 56X8 2,200-2,300 Narrow face, high speed. Earle C. Bacon 1,000 Cornish. Sturtevant Mill Co. 16X3 27X5 3,000 • Special cen- trifugal. E. P. Allis Co 20X12 26X14 30X14 36X14 i 800 Cornish. E. P. Allis Co 1,885 Narrow face, high speed. Colorado Ironworks 20X12 27X14 36 X 16 40X16 600 4,000 for hard rock. 4,800 for very hard rock. Cornish. Colorado Iron Works 36X6 42X6 54X8 2,100-2,800 Narrow face, high speed. Denver Engineering Works Co 20 X 12 to 36X16 350-100 3,500-4,500 Cornish. Gates Iron Works ... 9X4 26X15 36 X 15 470-850 2,266-3,333 Cornish. The Gates Iron Works has furnished the following formulas relating to crushing rolls, in which D = diameter of roll m inches; N == number of R. P. M.; S = maximum size of ore cube in inches fed to the rolls, S' = maximum size of cube for a given diameter of roll. oqo s N = f x isd- s ' = M76XZ> - It will be seen from the first of these formulas than N is an inverse function of S, which agrees with the results shown in the previous diagram. As a rule, it is best not to try to run rolls up to the maximum size that they will crush, but to feed smaller material to them. . ... The Denver Engineering Works Company has furnished the diagram, Fig. 9, and formulas relating to rolls. This diagram serves very well to illustrate the fact that small rolls do not grip or crush large pieces as well when running at comparatively high peripherial speeds as when running at slow speeds. In the case of the 10" X 16" roll, a difference of from 1" to cube size made a difference of 20 R. P. M. in order to obtain the 426 ORE DRESSING AND PREPARATION OF COAL. most effective crushing speed, and the difference between £" and £" cube sizes made a difference almost as great. It will also be noticed that the larger diameters, as, for instance, the 42" roll, are not so greatly affected by this cause, owing to the fact that the effective or crushing angle between the rolls is much more acute than in the case of the smaller diameters. CRUSHING MILLS. Radial Roller Mills.— In this type of mill, the crushing is performed on a ring or die by a series of heavy rolls pressing on it by gravity. In some cases, the rolls travel around on the die and in others the die travels in relation to the rolls. Fig. 10 represents one form of Chilian mill that is the leading type of this class. , , ,,, . ,, . .. The peculiarity of the grinding action of the radial rolling mills is that it is not a pure crushing action, but a triturating or grinding action as well, owing to the fact that while the different portions the face of the roll are all traveling at the same speed, the outer portions have to travel over a greater length of ring than the inner po tions, so that there is only one line along which true crushing action occurs. Some manufacturers have made the crushing ring and the rollers both with coning faces, the vertices of both cones meeting at a common point. This has resulted in a true crushing action, but for so'me classes of work the triturating action is to be preferred, as, for instance, in the grinding of silver ores for the patio process of amalgamation. , . Centrifugal Roller Mills.— In centrifugal roller nulls the crushing is accom- plished between rapidlv moving rolls and the inside of a stationary die or ring. The Huntington ‘mill. Fig. 11, is one of the principal representatives of this class of machinery. The rollers c are supported from bearings e and are carried rapidly around by means of the frame a and the ^Ihe ore is crushed against the ring d. In order to prevent the accumulation CRUSHING MILLS. 427 Fig. 10. of ore below the rollers, and to throw it out for crushing, scrapers / are pro- vided. The crushed ore discharges through screens, as shown in the illus- tration. There are many styles of this class of machinery having different numbers of rollers, varying from 1 up, and some machines have been intro- duced combining a portion of the action of radjal and centrifugal machines, the faces of the die or ring being at an angle and the rollers being mounted in inclined bearings so that they tend to crowd out and down upon the ring. Centrifugal roller mills have found two espe- cial fields in concentration works, one for crushing clay or soft ores containing free gold, and the other for re- grinding middlings for fur- ther concentration. Rolls of this type are also extensively employed in grinding cement and phosphate rocks. Ball Mills.— There are two types of ball mills: (1) those in which the crushing is per- formed by balls traveling in a fixed path, and (2) those in which the crushing is per- formed by a large mass of balls of various sizes rolling over one another. In the first type the balls travel in a fixed path, track, or race that may be either vertical or horizontal. Where it is vertical, the balls must be driven at such a rapid rate that their centrifugal force will keep them in contact with the crushing ring or track. This form may be likened to a bicycle ball bearing on a large scale, the crushing being accomplished between the balls and the race or track. The serious objec- tion to this class of ball mills is found in the uneven wear of both the balls and the race, so that the work soon becomes unevenly distributed, and also in the fact that the balls cannot be used after they have been worn to a slight extent. , . In the second class of machines the balls are introduced into a large barrel or chamber, where they roll over one another, the ore being crushed between the different balls and between the balls and the lin- ing of the chamber. In this style of machine the crushed material may be discharged through openings in the per- iphery or through openings in one end of the barrel. One great advantage with this style of mill is that the balls can be entirely worn out and it is only necessary to charge a sufficient number of new balls with the ore each day to make up for the wear of those in the mill. STAMPS. Gravity stamps are especially well suited for material the Fig. 11. valuable portion of which does not have a tendency to slime. The fact that these stamps are very simple in construction, easy to transport and erect, as well as to operate, gives them a decided advantage over other forms of crushers. Fig. 12 illustrates a 10-stamp battery of the gravity type. 428 ORE DRESSING AND PREPARATION OF COAL. Fie 13 is a detail of the mortar stamp heads and dies. The mortar a is placed on a suitable foundation of timbers b and the ore crushed on dies £ by the stamps s, which are secured by means of tapered joints to the he^s or bosses h The stems e are attached to the heads h and the whole lifted by the cams (shown in detail in Fig. 12). The cams operate under tappets on the stems as shown in Fig. 12. As the cam operates under the -edge of the tappet, it not only lifts the stamp, but gives a partial rotation, thus equalizing the wear on both the stamp and die. The ore is fed in at the back of the mortar and the crushed material discharged through the screen, as shown in Figs. 12 and 13 Usually a single screen at the front is employed, but sometimes two or more upon different sides of the mortar may be introduced. For treating free-milling gold ores in which the gold occurs in rather large grains free from iron pyrites, the California style of battery was developed, the charac- teristics of Which are a small drop (4 in. to 6 in.), low discharge ^m.U heavy stamp (750 to 1,000 lb.), and a high speed or number of drops permin- ute (90 to 105). The advantage of this style is rapid crushing, but the majority of the gold had to be saved on apron plates outside the mortar. For working ores that contain large quantities of iron pyrites with the g-old values occurring in the cleavage planes of the pyrites, the Gilpin County . Colo., style of battery was developed. This is characterized by a Loumy, y high drQp (lg tQ 20 in v a high discharge (14 in.), a light stamp (550 to 600 lb.), and a comparatively slow rate of drop (30 per minute) . With this style of battery, most of the gold was obtained on amalgamated plates in the battery, but its use was accompanied by excessive sliming on Fig. 12. Fig. 13. account of the fact that the high discharge kept the material m the mortar for a long time, and subjected it to repeated treatment. w Modern practice tends toward the use of rather heavy 1 000 lb ) quick drop (90 to 105 per minute), and low discharge (4 to 6 m.). The advantages are P tU the capacity of the hatte^ sliming - reduced to a minimum. If the ore contains sulphides carrying go , they afe separated by concentration upon manners or 1 amon nlates do subsea uentlv treated by chlorination or smelting. If the apron plates ao not catch the major portion of the values, the tailings may treated by t e cyanfdfproceT This last method is that employed at many large gold mines, especially those of the Transvaal in South Africa. T . . Order of Drop.— There is much diversity of practice m this respert. . It is desirable to drop the stamps in such rotation as to insure an even disti ^b tion of the pulp on the several dies. Adjacent stamps should not drop co ^ secutivelv, as this occasions accumulation of the pulp at one end of mortar in conseauence of which the efficiency of the stamps at that end is reduced by having a decreased height of drop and a cu shion pulverization of the ore. The stamps at the other themortarhave too little work, and are liable to “ pound iron.” The order of drop 1, 4, 2, 5, 3 STAMPS. 429 seems to best fulfil the requirements. It gives a good but the two just m 6 ?n i large & ^lfs ^lie stendanl^rop is gtven as 1 7, 3, 9, 5, 2, 8 , A 1CK 1 s, 4, 10,2, 7, 5, 9, 3 , 6 as a close favorite; while 1, 5, 9, 7, 3, 2, 6 , 10, 8 , 4 and 1,6 SDee 3 d of 'SUmps— Heav^stainps and stamps having high drops should KKrS.7S| 6 doK r dislodged! and breakage is imminent. A fast drop produces a good splash, which is very desirable for battery amalgamation. Shoes and Dies. — Shoes and dies are either of iron or steel. In most mills, remote from foundries where transportation is an important item m the cost nf^hops and dies steel shoes and dies have replaced those of iron. Chrome ° t f p S ( shot? and ^ dies have been introduced and have proved superior. In feme S S, steel shoesVd iron dies ; are used L The ^ £SS evenly with steel shoes than the steel dies do. The life is about 2. to 3 times that of iron shoes and dies, and the cost about twice as great as those of iron. The mixture of steel ( from the old chrome steel shoes and dies) with iron nrodS Xes and dVes Sat wear considerably longer than those of pure Son* and may be advantageously introduced l where r»n Z* Qj O "O 02 £ 02 Q. O 1 9.78 9.78 14.22 14.22 2 39.12 29.34 56.88 42.66 3 88.02 48.90 127.98 71.10 4 156.48 68.46 227.52 99.54 5 244.50 88.02 355.50 127.98 6 352.08 107.58 511.92 156.42 7 479.22 127.14 696.78 184.86 8 625.92 146.70 910.08 213.30 9 792.18 166.26 1,151.82 241.74 10 978.00 185.82 1,422.00 270.18 11 1,183.38 205.38 1,720.62 298.62 12 1,408.32 224.94 2,047.68 327.06 13 1,652.82 244.50 2,403.18 355.50 14 1,916.88 264.06 2,787.12 383.94 15 2,200.50 283.62 3,199.50 412.38 16 2,503.68 303.18 3,640.32 440.82 17 2,826.42 322.74 4,109.56 469.26 18 3,168.72 342.30 4,607.28 497.70 19 3,530.58 361.86 5,133.42 526.14 20 3,912.00 381.42 5,688.00 554.58 21 4,313.00 400.98 6,271.00 583.26 22 4,733.50 420.54 6,882.50 611.46 23 5,173.70 440.10 7,522.50 639.90 24 5,633.30 459.67 8,190.70 668.35 25 6,112.60 479.22 8,887.50 696.79 4-S P Horizontal Surface. bm. Sloping Surface. be. e rO A ■P ft o» p Total Pressure. Pressure Lowest Ft. Total Pressure. Pressure Lowest Ft. 26 6,611.1 498.78 9,612.8 725.21 27 7,129.5 518.35 10,366.0 753.67 28 7,667.6 537.90 11,149.0 782.10 29 8,225.0 557.46 11,988.0 810.54 30 8,802.0 577.01 12,797.0 839.00 31 9,398.5 596.59 13,665.0 867.41 32 10,015.0 616.14 14,561.0 895.86 33 10,650.0 635.70 15,486.0 924.30 34 11,306.0 655.26 16,439.0 952.70 35 11,980.0 674.81 17,420.0 981.19 36 12,675.0 694.39 18,429.0 1,009.60 37 13,389.0 713.94 19,467.0 1,038.10 38 14,123.0 733.50 20,533.0 1,066.50 39 14,875.0 753.07 21,629.0 1,095.00 40 15,648.0 772.63 22,752.0 1,123.40 41 16,440.0 792.20 23,904.0 1,151.80 42 17,252.0 811.74 25,084.0 1,180.30 43 18,083.0 830.73 26,293.0 1,208.70 44 18,934.0 850.86 27,530.0 1,237.20 45 19,804.0 870.41 28,793.0 1,265.60 46 20,695.0 889.99 30,090.0 1,294.00 47 21,605.0 909.54 31,412.0 1,322.30 48 22,533.0 929.10 32,763.0 1,350.90 49 23,482.0 948.66 34,143.0 1,379.40 50 24,450.0 968.21 35,550.0 1,407.90 Horsepowers for Coal Conveyors (Coal Included). Speed, 100 ft. per minute. Conveyors, 100 ft. long. Standard steel troughs. ■"I® °.o flP Size of Flights In. 4 X 10 4X12 5X12 5X15 6X18 Horizontal . Inclined. 12 In. Between Flights. 2 } 3 3* 4* 54 18 In. Between Flights. 2 24 3 34 44 12 In. Between Flights. 3 34 4 54 64 o .g N rd 5° Size of Flights. In. 5X15 6X18 8X 18 8 X 20 8 X 24 10 X 24 Horizontal. 16 In. Between Flights. 4 5 7 8 94 124 24 In. Between Flights. 34 4 5 6 7 8 Inclined. 16 In. Between Flights. 44 54 8 10 114 14 446 ORE DRESSING AND PREPARATION OF COAL. Weights and Capacities of Standard Steel Buckets. Chain. Size of Bucket. In. Weight of Bucket. Lb. Capacity of Bucket. Lb. Capacity of Elevator. 100' per Min. Number of Drawing. Lb. per Min. Net Tons per Hr. a> W) *d - 12 X 9 X 11? 181 11 1,100 33.0 5,357 o Q 14 X 9X11? 221 121 1,250 37.5 5,357 0 18 X 9X11? 27 161 1,650 49.5 5,357 24 X 9 X Ilf 36 22 2,200 66.0 5,357 12X10 X 161 20 19 1,380 41.4 5,357 tS bC 18 X 10 X 161 29 281 2,072 62.2 5,357 'O O 24X10X161 38 38 2,760 82.8 5,357 ft 30 X 10 X 161 461 471 3,450 103.5 5,357 a 18 X 12 X 161 31 33 2,400 72.0 5,357 24 X 12 X 161 40 44 3,200 96.0 5,357 30 X 12 X 161 48 55 4,000 120.0 5,357 Buckets taken £ full. Buckets continuous. 1 lb. of coal = 34 cu. in. Elevating Capacities of Malleable Iron Buckets. Table gives tons (2,000 lb.) of pea coal per hour at 100 ft. per minute. Buckets. Capacities. Distance Between Buckets in In. Size In. Wt. Lb. Cu. In. Lb. 8 10 1 12 14 16 18 20 22 24 2f X 4 0.75 15 0.48 2.16 1.73 1.44 1.23 1.08 1.94 31 x 5 1.50 31 0.97 4.36 3.49 2.91 2.49 2.18 4 X 6 2.00 51 1.57 7.06 5.65 4.71 4.04 3.53 3.14 2.83 3.81 41 x 7 2.56 75 2.33 10.38 8.39 6.99 5.99 5.19 4.66 4.19 4.72 5 x 8 3.56 102 3.15 11.34 9.45 8.10 7.09 6.30 5.67 5.15 6 x 10 5.47 185 5.73 17.19 14.73 12.88 11.46 10.31 9.38 8.59 7 x 12 8.97 287 8.90 22.88 20.02 17.80 16.02 14.56 13.35 7 X 14 11.41 295 9.14 20.56 18.28 16.45 14.95 13.71 10 X 18 1 1 Weight of 1 cu. ft. of pea coal = 53.5 lb. 32.3 cu. in., or .0187 cu. ft. = 1 lb. Conveying Capacities of Flights at 100 Ft. Per Minute. (Tons of Pea Coal per Hour.) Size of Flight. In. Horizontal. Inclined. 10° 20° 30° Lb. Coal per Flight. Every 16 In. Every 18 In. Every 24 In. Every 24 In. Every 24 In. Every 24 In. 4 X 10 33.75 30 22.5 15 18.0 14.25 10.5 4 X 12 42.75 38 28.5 19 24.0 18.00 13.5 5 X 12 51.75 46 34.5 23 28.5 22.50 16.5 5 X 15 69.75 62 46.5 31 40.5 31.50 22.5 6 X 18 80 60.0 40 49.5 40.50 31.5 8X18 8X 20 8 X 24 10 X 24 120 90.0 105.0 135.0 172.5 60 70 90 115 72.0 84.0 120.0 150.0 57.00 66.50 96.00 120.00 48.0 56.0 72.0 90.0 Note. — T hese ratings are for continuous feed. 2,000 lb. — 1 ton. HANDLING OF COAL. 447 Horsepower for Bucket Elevators, N = number taken from table; = height of elevatpr in feet; co = weight of material in one bucket; d = distance apart of buckets, in inches. Revolu- tions per Minute. Diameter of Head-Wheels. Revolu- tions per Minute. 22 In. 24 In. 26 In. 28 In. 30 In. 32 In. 10 .064 .070 .075 .080 .087 .093 10 12 .077 .083 .090 .097 .104 .111 12 14 .089 .096 .106 .114 .121 .130 14 16 .102 .111 .121 .130 .140 .148 16 18 .115 .125 .136 .146 .157 .167 18 20 .128 .139 .151 .162 .174 .186 20 22 .140 .153 .166 .179 .191 .204 22 24 .153 .167 .181 .195 .209 .223 24 26 .166 .181 .196 .211 .226 .242 26 28 .179 .195 .211 .227 .244 .260 28 30 .191 .209 .226 .244 .261 .279 30 32 .204 .223 .241 .260 .278 .297 32 34 .217 .237 .256 .276 .296 .316 34 36 .230 .251 .271 .292 .313 .334 36 38 .242 .265 .287 .309 .331 .353 38 40 .255 .279 .302 .325 .348 .372 40 COST OF UNLOADING COAL. Coal is generally unloaded from railroad cars into the hold of a vessel by some form of unloader, which usually raises the car bodily and dumps it directly into the hold of the vessel. In this way the cost of unloading has been reduced to a very small figure, and the speed of unloading greatly increased. The cost of unloading is given by the makers of the Brown hoist as varying from 2£ cents per ton up to 4£ cents per ton; deducting in each case 2 cents for trimming the coal in the vessel, the actual cost of loading varies from £ cent to 2£ cents per ton, depending on the conditions. Along the Lakes it is customary to pay a premium of £ cent per ton to all connected with the loading, for all coal loaded in excess of 2,500 tons per day and 1,800 tons per night. The Brown hoist has a guaranteed capacity of at least 800 tons per hour, but this has been greatly exceeded in practice TheMcMyler end dump has a record of 4.65 tons per minute, and the McMyler side dump of 8.41 tons per minute. These figures apply to the lake cities of the U. b. The C. W. Hunt Co., West New Brighton, N. Y., gives the follovvmg figures for handling coal along the Atlantic seaboard: The cost of shoveling coal by hand in the hold of the vessel into ordinary iron buckets is about 6 to 7 cents per ton of 2,000 lb.; the cost for iron ore, phosphate rock, or sand, about 10 i less. The cost of shoveling coal and hoisting it out of vessel to the wharf with an ordinary hoist with manila rope is 12 to 13 cents per ton, so that the hoisting costs about the same as the shoveling. The cost for both shoveling and hoisting with a steam engine is 10 to 11 cents per ton. ine cost when using a steam shovel or grab bucket for taking up coal out of the vessel varies greatly in different classes of vessels, but usually runs from about 1£ to 5 cents per ton, averaging about 3 cents. After the coal is hoisted, it can be carried into storage with an automatic railway or other efficient plant, at a cost of about 1 to 1£ cents per ton For great distances a cable railway or a convevor can be used, which handles the material about as cheaply as for short distances, but the cost of plant is greatly increased. In unloading anthracite from cars on a trestle into pockets or on the ground, the loss on all sizes is 2 to 3j$ when the coal is not resized; when it is resized the loss is 8£ to 9j&. 448 BEIQ UETING. The cost of stocking and unloading anthracite by the Dodge system is given by Mr. Piez, “ Mines and Minerals/ * June, 1898, page 488, as follows: Year. Engine Service, Stocking and Lifting, per Ton. Cents. Office Expense, per Ton. Cents. Steam, Wages and Fuel, per Ton. Cents. Labor, Dumping and Lifting, per Ton. Cents. Repairs, per Ton. Cents. Supplies, per Ton. Cents. Total, per Ton. Cents. 1895 .87 .29 .97 2.67 .78 .25 5.83 1896 .78 .30 .82 2.19 .90 .27 5.26 1897 .69 .32 .62 1.88 .97 .16 4.64 BRIQUETING. Machines Employed— Fuel, fuel dust, and other products may be briqueted by a number of different styles of machines, but all these may be divided into two classes, briquet and eggette machines. The eggette machines have a pair of rollers, the faces of which are provided with semispherical or semi- ovoid openings. The material that is fed between these rolls crowds into the openings of the two rolls, thus forming small spheres. The material is mixed with a suitable bond before being fed to the rolls, and the eggettes are received on any suitable form of traveling belt or chute and removed for drying or storage. This style of machine has not been used to any great extent in this country. The briqueting machines all act more or less on the principle of the brick machine, having some kind of a die or mold into which the material is crowded. The material is either pressed as it is being fed into the mold or subsequently by some form of plunger. For some materials, common brick machines, such as are used in the manu- facture of building brick, are employed, while in others special forms are necessary. , . Briqueting of Fuel.— Fuel briquets have not come into general use m the United States for two reasons: (1) on account of the great amount of cheap fuel available, which has prevented the utilization of culm, coal dust, etc.; and (2) on account of the lack of or high price of suitable bonding material. This latter condition is now being removed by the introduction of by-product coke ovens, from which supplies of coal tar can be obtained. Aside from peat and certain kinds of brown coal, and possibly some caking coals, it is neces- sary to employ a bond in the making of any fuel briquets. This is especially true in the case of anthracite coal The present tendency is to employ no inorganic bonding materials, as they increase the ash. The material to be briqueted should be as clean and free from dirt or slate as possible, and the particles should be of practically uniform size, the most satisfactory product being from coal crushed to about fin. cube size. The coal must be thor- oughly mixed with bonding material and then subjected to a heavy pressure. One advantage claimed for briquets is that they can be made of such a form as to occupy less space than the original fuel. The French navy has found it possible to store 10^ more briquets than coal in a given space, and also that the loss by breakage and pulverization is very much less. Under favor- able conditions, fuel can be briqueted for 20 cents per ton, and the following are some of the advantages claimed for these briquets: They are sound throughout and will not decrepitate while burning, thus reducing the loss by fine material working through the grates. The bond, if properly selected, renders the briquets practically waterproof, so that they are not injured if kept in storage, do not evolve combustible gases, nor ignite from spontaneous combustion. There is no fine material mixed with the briquets, and hence a more uniform fire can be maintained with them. Briqueting of Flue Dust.— Flue dust from iron blast furnaces has been suc- cessfully briqueted in a number of instances. One firm employs a common brick machine, making bricks 2£ in. X 4f in. X 9 in. With this machine, they mix the flue dust with 3$ of lime and 3^ of cement, the lime acting as a flux in the furnace. These machines work with comparatively light pres- sure. When regular briqueting machines, producing round bricks and TREATMENT OF INJURED PERSONS. 449 employing high pressures are employed, no cementne^ being mixed with 4 4 to are loaded ^into barrels and taken direct to the blast furnace, with as u Another firm, figuring on a basis of 130 tons per 24 hours, and using 3j6 lime in the solution, gave the following figures: 4 tons lime, 13.00 per **r:5 2 machine tenders (day and night), 12hours, at #2.50... 2 laborers (day and night), 12 hours, at $1.75 Oil and waste - - Interest on cost of plant 1 . ^ ' Thi* is less than 20 cents per ton. This estimate does not take into con- sideration the cost of power, which would be about 35 H. P., nor does it take into consideration hauling of material to plant and removing of briquets. Cubic Feet Occupied by 2,000 Pounds of Yabious Coals. ( Link-Belt Engineering Co ., Philadelphia , Pa.) 5.00 3.50 2.00 1.50 Varieties. Lackawanna, anthracite.. Garfield red ash, anthracite . Ly kens Valley, anthracite .... Shamokin, anthracite : -— Plymouth red ash, anthracite. Wilkes-Barre, anthracite Lehigh, anthracite Lorberry, anthracite Scranton, anthracite Pittston, anthracite Broken. Egg. Stove. 37.10 36.65 34.90 37.30 36.95 36.35 37.55 37.25 37.55 38.05 37.70 37.25 34.90 34.85 34.75 34.95 34.35 33.75 33.30 33.80 33.55 34.65 34.20 33.80 35.35 35.20 34.60 35.45 34.95 34.35 34.35 36.35 37.25 37.25 34.70 34.00 32.55 33.55 33.30 33.70 Pea, 37.25 37.50 38.50 38.50 36.90 36.90 33.05 35.20 34.95 35.50 Cumberland, bituminous 36.65 Clearfield, bituminous 33.55 New River, bituminous. | 40.15 Pocahontas, bituminous American cannel, bituminous English cannel, bituminous... 34.00 41.50 42.30 TREATMENT OF INJU RED PERSONS. The dangers to be feared in case of wounds, are: shock or collapse , loss of blood , and unnecessary suffering in the moving qf the P at ™nt. insen- Tn shock the iniured person lies pale, faint, and cold, sometimes sible with feeble pulse and superficial breathing. The cause of death in case of a shock is arrest of heart action, produced by the suspension of the functions of the brain and spinal cord. In treatment, the two most import- ant" of the injured person; (2) the application of eX ThTinTured^erson should at once be placed in a recumbent portion, his head resting 1 on a plane lower than that of his trunk, legs, and feet. He should be lell wrapped up and protected from the chilling influences of external air When there is danger of immediate death, stimulants should bfliven; in all other conditions of shock, stimulants are injurious Sss of Blood. — In case of loss of blood, two conditions P res ^\thems^ m \ The bleeding is arrested spontaneously or otherwise, but the injured tli symptoms of loss .of blood; (2 'the injured pers0 n is actually bleeding and he is, or is not, suffering from loss of blood. In the first condition, life is threatened by anemia .of brain spinal cord, and all the efforts of treatment are to direct the flow of whatever 450 TEE A TMENT OF INJURED PERSONS. quantity of blood may still remain in the body to the vital centers in the brain and spinal cord. This is most efficiently done by placing the injured person in a recumbent position, with his head resting on a plane somewhat Fig. 1. Fig. 2. lower than that of his trunk and legs. In graver cases, constricting bands should be applied to both arms, as near the shoulders as possible, and to both thighs, as near the abdomen as possible. This last maneuver directs the entire quantity of blood in the body to the suffering centers, the centers of life itself. Stimulants may be sparingly administered. If there is bleeding, do not try to stop it by binding up the wound. The current of blood to the part must be checked. To do this, find the artery, by *ts beating; lay a firm and even compress or pad (made of cloth or rags rolled up, or a round stone or piece of wood well wrapped) over the artery ( Fig. 1 ) . Tie a handkerchief around the limb and compress; put a bit of stick through the handkerchief and twist the latter up until it is just tight enough to stop the bleed- ing; then put one end of the stick under the handkerchief, to prevent untwisting, as in Fig. 2. The artery in the thigh runs along the inner side of the muscle in front near the bone, as shown by dotted line in Fig. 8. A little above the knee it passes to the back of the bone. In injuries at or above the knee, apply the compress higher up. on the inner side of the thigh, at the point P, Fig. 3, with the knot on the outside of the thigh. When the leg is injured below the knee, apply the compress at the back of the thigh, just above the knee, at P, Fig. 4, and the knot in front, as in Figs. 1 and 2. The artery in the arm runs down the inner side of the large muscle in front, quite close to the bone, as shown by dotted line; low down it is further forwards, towards the bend of the elbow. It is most easily compressed a little above the middle, at P. Fig. 5. Care should be taken to examine the limb from time to time, and to lessen the compression if it becomes cold or purple; tighten up the handkerchief again if the bleeding begins afresh. To Transport a Wounded Person Comfortably. Make a soft and even bed for the injured part, of straw, folded blankets, quilts, or Fig. 3. Fig. 4. Fig. 5 Fig. 6. pillows, laid on a board with side pieces of board nailed on. when this can be done. If possible, let the patient be laid on a door, shutter, settee, or some firm support, properly covered. Have sufficient force to lift him steadily, and let those that bear him not keep step. Should any important arteries be opened, apply the handkerchief, as recommended. Secure the vessel by a surgeon’s dressing forceps, or by a TREATMENT OF PERSONS OVERCOME BY GAS. 451 hook then have a silk ligature put around the vessel, and tighten, should the bleeding be from arterial vessels of small size, apply persulphate of iron, either in tmcture or in powder, by wetting a piece of lmt or sponge with the solution 1 then after bleeding ceases, apply a compress against the parts, to sustain them during the application of the persulphate of iron, and to vent ^ furthe^bleeding, should it occur. The persulphate of iron should be ke meedin^rom 1 1 cVl^WoTivc! A %ad or compress is placed immediately before the ear over the region marked by a dotted line, Fig. 6. The com- nress is firmly secured by a handkerchief. If this ^o®s not ^rest bleeding, a similar compress on the opposite side should be applied. Should the bleed- inTissurfmmTwound of the posterior or back part of the head, a compress should be placed behind the ear, over the region marked by the dotted line, Fig. 6, and firmly secured by a handkerchief or bandage. TREATMENT OF PERSONS OVERCOME BY GAS. Miners are exposed to asphyxia when the circulation of the air is not suf- ficiently active, when the mine exhales a quantity of deleterious gas, when they imprudently penetrate into old and abandoned workings, and when th6 The symptoms of asphyxia are sudden cessation of the respiration, of the pulsations of the heart, and of the action of the senses; the swollen and marked with reddish spots, the eyes are protruded, the features are distorted, and the face is often livid, etc. . ^ The best and first remedy to employ, and m which the greatest confidence ought to be placed, is the renewal of the air necessary for respiration. Pr T ee prompflywithdraw the asphyxiated person from the deleterious place and exf^se^him^to roun( j the neck and chest, and dash cold water in ‘ke^ace^and s hould e be h made to irritate the mucous membrane with i the feathered end of a quill, which should be gently moved in the nostrils of the insensible person, or to stimulate it with a bottle of volatile alkali placed under .tbe ^ U p wa rmth of the body, and apply mustard plasters over the heart an pro duce respiration, Doctor Sylvester’s method of producing artificial respiration should be tried as follows: Place the patient on the back on a flat surface, inclined a little upwards from the feet; raise and support the head and shoulders on a smaU firm cushion or folded article of dress placed under the shoulder blades. D raw forwards the patient’s tongue and keep it projecting beyond the lips, an elastic band over the tongue and under the chin will answer this purpose, or a piece of string or tape may be tied around them, or by raising the lower iaw the teeth may be made to retain the tongue in that position. Remove all tight clothing from about the neck and chest, especially the suspenders. Then g standing at the patient’s head, grasp the arms just above the elbows, and draw the arms gently and steadily upwards above the head, and keep them stretched upwards for 2 seconds (by this means air is diawn into the lungs'). Then turn down the patient’s arms and press them gently and firmly for 2 seconds against the sides of the chest (by this means air is Pressed out of the lungs) . Repeat these measures alternately , deliberately , and per- severingly about 15 times in a minute, until a spipntaneous effort to respire is perceived, immediately upon which cease to imitate the movements of breathing, and proceed to induce circulation and warmth. 6 To promote warmth and circulation, rub the limbs upwards with firm, grasping pressure and energy, using handkerchiefs flannels, etc. Apply hot flannels! bottles of hot water, heated bricks, etc. to the pit of the stomach, the arm pits, between the thighs, and to the soles of the feet. , . 7 On the restoration of life, a teaspoonful of warm water should be given, and then, if the power of swallowing has returned, small quantities of wine, warm brandy and water, or coffee should be administered. 8. These remedies should be promptly applied, and as death does not certainly appear for a long time, they ought only to be discontinued^ when it is clearly confirmed. Absence of the pulsation of the heart is not a sure sign of death, neither is the want of respiration. 452 COAL DEALER'S TABLE. Coal Dealers’ Computing Table, for Ascertaining the Price of Any Number of Pounds, at a Given Price per Ton of 2,000 Pounds. Lb . $0.75 $1.00 $1.25 $1.50 $1.75 $2.00 $2.25 $2.50 $2.75 10 .01 .01 .01 .01 .01 .01 .01 .01 .01 20 .01 .01 .01 .02 .02 .02 .02 .03 .03 30 .01 .02 .02 .02 .03 .03 .03 .04 .04 40 .02 .02 .03 .03 .04 .04 .04 .05 .06 50 .02 .02 .03 .04 .04 .05 .06 .06 .07 60 .02 .03 .04 .05 .05 .06 .07 .08 .08 70 .03 .03 .04 .05 .06 .07 .08 .09 .10 80 .03 .04 .05 .06 .07 .08 .09 .10 .11 90 .03 .04 .06 .07 ..08 .09 .10 .11 .12 100 .04 .05 .06 .08 .09 .10 .11 .13 .14 200 .08 .10 .13 .15 .17 .20 .23 .25 .28 300 .11 .15 .19 .23 .26 .30 .34 .38 .41 400 .15 .20 .25 .30 .35 .40 .45 .50 .55 500 .19 .25 .31 .38 44 .50 .56 .63 .69 600 .23 .30 .37 .45 .53 .60 .68 .75 .83 700 .26 .35 .44 .53 .61 .70 .77 .88 .96 800 .30 .40 .50 .60 .70 .80 .90 1.00 1.10 900 .34 .45 .56 .68 .79 .90 1.01 1.13 1.24 1,000 .38 .50 .63 .75 .88 1.00 1.13 1.25 1.38 1,100 .41 .55 .69 .83 .96 1.10 1.24 1.38 1.51 1,200 .45 .60 .75 .90 1.05 1.20 1.35 1.50 1.65 L 300 .49 .65 .81 .98 1.14 1.30 1.46 1.63 1.79 L 400 .52 .70 .88 1.05 1.22 1.40 1.58 1.75 1.93 1,500 .56 .75 .94 1.13 1.31 1.50 1.69 1.88 2.06 1,600 .60 .80 1.00 1.20 1.40 1.60 1.80 2.00 2.20 1,700 .64 .85 1.06 1.28 1.49 1.70 1.91 2.13 2.34 1,800 .68 .90 1.13 1.35 1.58 1.80 2.03 2.25 2.48 1,900 .71 .95 1.19 1.43 1.66 1.90 2.14 2.38 2.61 Lb . $3.00 $3.25 $3.50 $3.75 $4.00 $4.25 $4.50 $4.75 $5.00 10 .02 .02 .02 .02 .02 .03 .03 .03 20 .03 .03 .04 .04 .04 .05 .05 .05 .05 30 .05 .05 .05 .06 .06 .07 .07 .07 .08 40 .06 .07 .07 .08 .08 .09 .09 .10 .10 50 .08 .08 .09 .09 .10 .11 .12 ,12 .13 60 .09 .10 .11 .11 .12 .13 .14 .15 .15 70 .11 .11 .12 .13 .14 .15 .16 .17 .18 80 .12 .13 .14 .15 .16 .17 .18 .19 .20 90 .14 .15 .16 .17 .18 .19 .20 .22 .23 100 .15 .16 .18 .19 .20 .22 .23 .24 .25 200 .30 .33 .35 .38 .40 .43 .45 .48 .50 300 .45 .49 .53 .56 .60 .64 .68 .72 .75 400 .60 .65 .70 .75 .80 .85 .90 .95 1.00 500 .75 .81 .88 .94 1.00 1.07 1.13 1.19 1.25 600 .90 .98 1.05 1.13 1.20 1.28 1.35 1.43 1.50 700 1.05 1.14 1.23 1.31 1.40 1.49 1.58 1.67 1.75 800 1.20 1.30 1.40 1.50 1.60 1.70 1.80 1.90 2.00 900 1.35 1.46 1.58 1.69 1.80 1.92 2.03 2.14 2.25 1,000 1.50 1.63 1.75 1.88 2.00 2.13 2.25 2.38 2.50 1,100 1.65 1.79 1.93 2.06 2.20 2.34 2.48 2.62 2.75 1,200 1.80 1.95 2.10 2.25 2.40 2.55 2.70 2.85 3.00 1,300 1.95 2.11 2.28 2.44 2.60 2.77 2.93 3.09 3.25 1,400 2.10 2.28 2.45 2.63 2.80 2.98 3.15 3.33 3.50 1,500 2.25 2.44 2.63 2.81 3.00 3.19 3.38 3.57 3.75 1,600 2.40 2.60 2.80 3.00 3.20 3.40 3.60 3.80 4.00 1,700 2.55 2.76 2.98 3.19 3.40 3.62 3.83 4.04 4.25 1,800 2.70 2.93 3.15 3.38 3.60 3.83 4.05 4 28 4.50 1,900 2.85 3.09 3.33 3.56 3.80 4.04 4.28 4.52 4.75 NATURAL SINES AND COSINES, 453 TABLE OF NATURAL SINES, COSINES, TANGENTS, AND COTANGENTS. EXPLANATION. Given an angle, to find its sine, cosine, tangent, and cotangent: Example— Find the sine, cosine, tangent, and cotangent of 37° 24 . . Look in the table of natural sines along the tops of the pages, and find 37 . Glancing down the left-hand column marked ('), until 24 is found, find opposite this 24 in the column marked sine and headed 3/°, the number .60738; then .60738 = sin 37° 24'. Similarly, find m the column marked cosine and headed 37°, the number .79441, which corresponds to cos 3/° 24'. So also, find in the column marked tangent and headed 3/°, and opposite 24 , the number .76456; and in the column marked cotangent and headed 37 , ana opposite 24', the number 1.30795. , , , ... . ... In most of the tables published, the angles run only from 0° to 45° at the heads of the columns; to find an angle greater than 45°, look at the bottom of the vaqe and glance upwards , using the extreme right-hand column to find minutes , which begin with 0 at the bottom and run upwards, 1, 2, 3, etc. up to 60. Example.— Find the sine of 77° 43'. _ _ . , Look along the bottom of the tables until the column marked sine and marked 77° is found. Glancing up the column of minutes on the right until 43 ' is found, find opposite 43 ' in the column marked sine at the bottom and marked 77°, the number .97711; this is the sine of //°43 . Similarly, the cosine, tangent, and cotangent may be found. To find the sine, cosine, tangent, or cotangent Of an angle whose exact value is not given in the table: , . r u | e —Find in the table the sine , cosine , tangent , or cotangent corresponding to the degrees and minutes of the angle. . For the seconds, find the difference of the values of the sine, cosine, tangent, or cotangent taken from the table between which the seconds of the angle fall; multiply this difference by a fraction whose numerator is the number of seconds m the given angle and whose denominator is 60 . . . , ^ v If sine or tangent, add this correction to the value first found; if cosine or cotangent, subtract the correction. Example.— Find the sine, cosine, tangent, and cotangent of 56 43 17 . Sin 56° 43' = .83597. Sin 56° 44' = .83613. Since 56° 43 17 is greater than 56° 43 ' and less than 56° 44 ', the value of the sine of the angle lies between V? * 2 a ’ QQC 1 Q QQWV7 — 0001 mil 1 tlTll VI T1 & til 0.11 OO 11 i Hlv V tllUC LAAvy oaaav/ p « . « i • “83597 and .83613; the difference equals .83613 — .83597 = .00016; multiplying this by the fraction M, .00016 X ii = 00005. nearly, which is to be added .00005, nearly, which is to be added to .83597, the "value first found', or .83597 + .00005 = .83602. Hence, sm 56° 43' 1 7" = 83602 Cos 56° 43' = 54878; cos 56° 44' = .54854; the difference equals .54878 _ 54054 _> 00024 and .00024 Y U = .00007, nearly. Now, since the cosine is deshed! we must’ sSak this correction from cos 56° 43' or .54878; subtract- ing, .54878 - .00007 = .54871. Hence, cos 56° 43' 17" = .54871. . Given the sine, cosine, tangent, or cotangent, to find the angle corresponding^ Example.— The sine of an angle is .47486; what is the angle? ,, Consulting the table of natural sines, glance down the columns marked sine until .47486 is found, opposite 21 ' in the ^ft-hand column and under the column headed 28°. Therefore, the angle whose sine = .47486 is 28° 21 , or sin 28° 21' = .47486. To find the angle corresponding to a given sine, cosine, tangent, or cotangent whose exact value is not contained in the table: ... R U | %—Find the difference of the two numbers in the table between which the given sine , cosine, tangent, or cotangent falls, and use the number of parts m this difference as the denominator of a fraction. 454 NATURAL SINES AND COSINES. Find the difference between the number belonging to the smaller angle and the given sine , cosine, tangent , or cotangent, and use the number of parts in the dif- ference just found, as the numerator of the fraction mentioned above. Multiply this fraction by 60, and the result will be the number of seconds to be added to the smaller angle. . , Example. — Find the angle whose sine equals .5/698. . Looking in the table of natural sines, in the column marked sine, it is found between .57691 = sin 35° 14' and .57715 = 35° 15'. The difference between them is .57715 — .57691 = .00024, or 24 parts. The difference between the sine of the smaller angle, or sin 35° 14' = .57691, and the given sine, or .57698, is .57698 — .57691 = .00007, or 7 parts. . „ Then, ^ X 60 = 17.5", and the angle = 35° 14' 17.5", or sm 3o° 14 17.(/ = .57698. „ „ . . _ The cosecant of an angle is equal to the reciprocal of its sine, and the secant is equal to the reciprocal of its cosine. Hence, to multiply a quantity bv the cosecant, divide it by the sine; or, to divide it by the cosecant niultiplv it bv the sine. Similarlv, to multiply a quantity by the secant ol an angle, divide it by the cosine; or, to divide it by the secant, multiply it by the cosine. NATURAL SINES AND COSINES. 455 0° 1° 2° 3 ° 4 ° / / Sine Cosine Sine Cosine Sine Cosine Sine Cosine Sine Cosine 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 .00000 .00029 .00058 .00087 .00116 .00145 .00175 .00204 .00233 .00262 .00291 .00320 .00349 .00378 .00407 .00436 .00465 .00495 .00524 .00553 .00582 .00611 .00640 .00669 .00698 .00727 .00756 .00785 .00814 .00844 .00873 .00902 .00931 .00960 .00989 .01018 .01047 .01076 .01105 .01134 .01164 .01193 .01222 .01251 .01280 .01309 .01338 .01367 .01396 .01425 .01454 .01483 .01513 .01542 .01571 .01600 .01629 .01658 .01687 .01716 .01745 1 . 1 . 1 . 1 . 1 . 1 . 1 . 1 . 1 . 1 . 1 . .99999 .99999 .99999 .99999 .99999 .99999 .99999 .99999 .99998 .99998 .99998 .99998 .99998 .99998 .99997 .99997 .99997 .99997 .99996 .99996 .99996 .99996 .99995 .99995 .99995 .99995 .99994 .99994 .99994 .99993 .99993 .99993 .99992 .99992 .99991 .99991 .99991 .99990 .99990 .99989 .99989 .99989 .99988 .99988 .99987 .99987 .99986 .99986 .99985 .99985 .01745 .01774 .01803 .01832 .01862 .01891 .01920 .01949 .01978 .02007 .02036 .02065 .02094 .02123 .02152 .02181 .02211 .02240 .02269 .02298 .02327 .02356 .02385 .02414 .02443 .02472 .02501 .02530 .02560 .02589 .02618 .02647 .02676 .02705 .02734 .02763 .02792 .02821 .02850 .02879 .02908 .02938 .02967 .02996 .03025 .03054 .03083 .03112 .03141 .03170 .03199 .03228 .03257 .03286 .03316 .03345 .03374 .03403 .03432 .03461 .03490 .99985 .99984 .99984 .99983 .99983 .99982 .99982 .99981 .99980 .99980 .99979 .99979 .99978 .99977 .99977 .99976 .99976 .99975 .99974 .99974 .99973 .99972 .99972 .99971 .99970 .99969 .99969 .99968 .99967 .99966 .99966 .99965 .99964 .99963 .99963 .99962 .99961 .99960 .99959 .99959 .99958 .99957 .99956 .99955 .99954 .99953 .99952 .99952 .99951 .99950 .99949 .99948 .99947 .99946 .99945 .99944 .99943 .99942 .99941 ,99940 .99939 .03490 .03519 .03548 .03577 .03606 .03635 .03664 .03693 .03723 .03752 .03781 .03810 .03839 .03868 .03897 .03926 .03955 .03984 .04013 .04042 .04071 .04100 .04129 .04159 .04188 .04217 .04246 .04275 .04304 .04333 .04362 .04391 .04420 .04449 .04478 .04507 .04536 .04565 .04594 .04623 .04653 .04682 .04711 .04740 .04769 .04798 .04827 .04856 .04885 .04914 .04943 .04972 .05001 .05030 .05059 .05088 .05117 .05146 .05175 .05205 .05234 .99939 .99938 .99937 .99936 .99935 .99934 .99933 .99932 .99931 .99930 .99929 .99927 .99926 .99925 .99924 .99923 .99922 .99921 .99919 .99918 .99917 .99916 .99915 .99913 .99912 .99911 .99910 .99909 .99907 .99906 .99905 .99904 .99902 .99901 .99900 .99898 .99897 .99896 .99894 .99893 .99892 .99890 .99889 .99888 .99886 .99885 .99883 .99882 .99881 .99879 .99878 .99876 .99875 .99873 .99872 .99870 .99869 .99867 .99866 .99864 .99863 .05234 .05263 .05292 .05321 .05350 .05379 .05408 .05437 .05466 .05495 .05524 .05553 .05582 .05611 .05640 .05669 .05698 .05727 .05756 .05785 .05814 .05844 .05873 .05902 .05931 .05960 .05989 .06018 .06047 .06076 .06105 .06134 .06163 .06192 .06221 .06250 .06279 .06308 .06337 .06366 .06395 .06424 .06453 .06482 .06511 .06540 .06569 .06598 .06627 .06656 .06685 .06714 .06743 .06773 .06802 .06831 .06860 .06889 .06918 .06947 .06976 .99863 .99861 .99860 .99858 .99857 .99855 .99854 .99852 .99851 .99849 .99847 .99846 .99844 .99842 .99841 .99839 •99838 .99836 .99834 .99833 .99831 .99829 .99827 .99826 .99824 .99822 .99821 .99819 .99817 .99815 .99813 .99812 .99810 .99808 .99806 .99804 .99803 .99801 .99799 .99797 .99795 .99793 .99792 .99790 .99788 .99786 .99784 .99782 .99780 .99778 .99776 .99774 .99772 .99770 .99768 .99766 .99764 .99762 .99760 .99758 .99756 .06976 .07005 .07034 .07063 .07092 .07121 .07150 .07179 .07208 .07237 .07266 .07295 .07324 .07353 .07382 .07411 .07440 .07469 .07498 .07527 .07556 .07585 .07614 .07643 .07672 .07701 .07730 .07759 .07788 .07817 .07846 .07875 .07904 .07933 .07962 .07991 .08020 .08049 .08078 .08107 .08136 .08165 .08194 .08223 .08252 .08281 .08310 .08339 .08368 .08397 .08426 .08455 .08484 .08513 .08542 .08571 .08600 .08629 .08658 .08687 .08716 .99756 .99754 .99752 .99750 .99748 .99746 .99744 .99742 .99740 .99738 .99736 .99734 .99731 .99729 .99727 .99725 .99723 .99721 .99719 .99716 .99714 .99712 .99710 .99708 .99705 .99703 .99701 .99699 .99696 .99694 .99692 .99689 .99687 .99685 .99683 .99680 .99678 .99676 .99673 .99671 .99668 .99666 .99664 .99661 .99659 .99657 .99654 .99652 .99649 .99647 .99644 .99642 .99639 .99637 .99635 .99632 .99630 .99627 .99625 .99622 .99619 60 59 58 57 56 55 54 53 52 51 50 49 48 47 46 45 44 43 42 41 40 39 38 37 36 35 34 33 32 31 30 29 28 27 26 25 .24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9 8 « 7 6 5 4 3 2 1 0 t / Cosine Sine Cosine ! Sine Cosine Sine Cosine Sine Cosine Sine 89 ° 88 ° 87 ° 86° 85 ° 456 NA TURAL SINES AND COSINES. 5° 6° 7° 8° 9° t / Sine Cosine Sine Cosine Sine Cosine Sine Cosine Sine Cosine o 08716 .99619 .10453 .99452 .12187 .99255 .13917 .99027 .15643 .98769 60 1 08745 .99617 .10482 .99449 .12216 .99251 .13946 .99023 .15672 .98764 59 08774 .99614 .10511 .99446 .12245 .99248 .13975 .99019 .15701 .98760 58 3 08803 99612 .10540 .99443 .12274 .99244 .14004 .99015 .15730 .98755 57 08831 99609 .10569 .99440 .12302 .99240 .14033 .99011 .15758 .98751 56 5 08800 99607 .10597 .99437 .12331 .99237 .14061 .99006 .15787 .98746 55 0 *08889 .99604 .10626 .99434 .12360 .99233 .14090 .99002 .15816 .98741 54 7 08918 .99602 .10655 .99431 .12389 .99230 .14119 .98998 .15845 .98737 53 g 08947 .99599 .10684 .99428 .12418 .99226 .14148 .98994 .15873 .98732 52 9 08976 .99596 .10713 .99424 .12447 .99222 .14177 .98990 .15902 .98728 51 10 !o9005 .99594 .10742 .99421 .12476 .99219 .14205 .98986 .15931 .98723 50 09034 99591 .10771 .99418 .12504 .99215 .14234 .98982 .15959 .98718 49 09063 99588 .10800 .99415 .12533 .99211 .14263 .98978 .15988 .98714 48 13 09092 99586 .10829 .99412 .12562 .99208 .14292 .98973 .16017 .98709 47 09121 99583 .10858 .99409 .12591 .99204 .14320 .98969 .16046 .98704 46 15 09150 99580 .10887 .99406 .12620 .99200 .14349 .98965 .16074 .98700 45 09179 99578 .10916 .99402 .12649 .99197 .14378 .98961 .16103 .98695 44 09908 99575 .10945 .99399 .12678 .99193 .14407 .98957 .16132 .98690 43 09937 99572 .10973 .99396 .12706 .99189 .14436 .98953 .16160 .98686 42 19 09266 .99570 .11002 .99393 .12735 .99186 .14464 .98948 .16189 .98681 41 20 ^09295 .99567 .11031 .99390 .12764 .99182 .14493 .98944 .16218 .98676 40 21 09324 .99564 .11060 .99386 .12793 .99178 .14522 .98940 .16246 .98671 39 22 09353 .99562 .11089 .99383 .12822 .99175 .14551 .98936 .16275 .98667 38 23 09382 99559 .11118 .99380 .12851 .99171 .14580 .98931 .16304 .98662 37 94- 0941 1 .99556 .11147 .99377 .12880 .99167 .14608 .98927 .16333 .98657 36 25 09440 .99553 .11176 .99374 .12908 .99163 .14637 .98923 .16361 .98652 35 26 09469 .99551 .11205 .99370 .12937 .99160 .14666 .98919 .16390 .98648 34 27 *09498 .99548 .11234 .99367 .12966 .99156 .14695 .98914 .16419 .98643 33 28 ]09527 .99545 .11263 .99364 .12995 .99152 .14723 .98910 .16447 .98638 32 29 !o9556 .99542 .11291 .99360 .13024 .99148 .14752 .98906 .16476 .98633 31 30 ]o9585 .99540 .11320 .99357 .13053 .99144 .14781 .98902 .16505 .98629 30 31 .09614 .99537 .11349 .99354 .13081 .99141 .14810 .98897 .16533 .98624 29 32 .09642 .99534 .11378 .99351 .13110 .99137 .14838 .98893 .16562 .98619 08 33 .09671 .99531 .11407 .99347 .13139 .99133 .14867 .98889 .16591 .98614 27 34 .09700 ^99528 .11436 .99344 .13168 .99129 .14896 .98884 .16620 .98609 | 26 35 .09729 .99526 .11465 .99341 .13197 .99125 .14925 .98880 .16648 .98604 25 36 .09758 .99523 .11494 .99337 .13226 .99122 .14954 .98876 .16677 .98600 24 37 .09787 .99520 .11523 .99334 .13254 .99118 .14982 .98871 .16706 .98595 23 38 .09816 .99517 .11552 .99331 .13283 .99114 .15011 .98867 .16734 .98590 22 39 .09845 .99514 .11580 .99327 .13312 .99110 .15040 .98863 .16763 .98585 21 40 !09874 .99511 .11609 .99324 .13341 .99106 .15069 .98858 .16792 .98580 20 41 .09903 .99508 .11638 .99320 .13370 .99102 .15097 .98854 .16820 .98575 19 42 .09932 .99506 .11667 .99317 .18399 .99098 .15126 .98849 .16849 .98570 18 43 !o9961 .99503 .11696 .99314 .13427 .99094 .15155 .98845 .16878 .98565 17 44 !o9990 .99500 .11725 .99310 .13456 .99091 .15184 .98841 .16906 .98561 16 45 J0019 .99497 .11754 .99307 .13485 .99087 .15212 .98836 .16935 .98556 15 46 J0048 .99494 .11783 .99303 .13514 .99083 .15241 .98832 .16964 .98551 14 47 .10077 .99491 .11812 .99300 .13543 .99079 .15270 .98827 .16992 .98546 13 48 .10106 .99488 .11840 .99297 .13572 .99075 .15299 .98823 .17021 .98541 12 49 !l0135 .99485 .11869 .99293 .13600 .99071 .15327 .98818 .17050 .98536 11 50 '.10164 .99482 .11898 .99290 .13629 .99067 .15356 .98814 .17078 .98531 10 51 .10192 .99479 .11927 .99286 .13658 .99063 .15385 .98809 .17107 .98526 9 52 !l0221 .99476 .11956 .99283 .13687 .99059 .15414 .98805 .17136 .98521 8 53 !l0250 .99473 .11985 .99279 .13716 .99055 .15442 .98800 .17164 .98516 7 54 .10279 .99470 .12014 .99276 .13744 .99051 .15471 .98796 .17193 .98511 6 55 !l03G8 .99467 .12043 .99272 .13773 .99047 .15500 .98791 .17222 .98506 5 56 .10337 .99464 .12071 .99269 .13802 .99043 .15529 .98787 .17250 .98501 4 57 .10366 .99461 .12100 .99265 .13831 .99039 .15557 .98782 .17279 .98496 3 58 .10395 .99458 .12129 .99262 .13860 .99035 .15586 .98778 .17308 .98491 2 59 J0424 .99455 .12158 .99258 .13889 .99031 .15615 .98773 .17336 .98486 1 60 ’.10453 .99452 .12187 .99255 .13917 .99027 .15643 .98769 .17365 .98481 0 Cosine Sine Cosine Sine Cosine Sine Cosine Sine Cosine Sine / f 84° 83° 82° 81° 80° NATURAL SINES AND COSINES. 457 10° 11° 12° 13° 14 c > r t - Sine Cosine Sine Cosine Sine Cosine Sine Cosine Sine Cosine 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 69 80 .17365 .17393 .17422 .17451 .17479 .17508 .17537 .17565 .17594 .17623 .17651 .17680 .17708 .17737 .17766 .17794 .17823 .17852 .17880 .17909 .17937 .17966 .17995 .18023 .18052 .18081 .18109 .18138 .18166 .18195 .18224 .18252 .18281 .18309 .18338 .18367 .18395 .18424 .18452 .18481 .18509 .18538 .18567 .18595 .18624 .18652 .18681 .18710 .18738 .18767 .18795 .18824 .18852 .18881 .18910 .18938 .18967 .18995 .19024 .19052 .19081 .98481 .98476 .98471 .98466 .98461 .98455 .98450 .98445 .98440 .98435 .98430 .98425 .98420 .98414 .98409 .98404 .98399 .98394 .98389 .98383 .98378 .98373 .98368 .98362 .98357 .98352 .98347 .98341 .98336 .98331 .98325 .98320 .98315 .98310 .98304 .98299 .98294 .98288 .98283 .98277 .98272 .98267 .98261 .98256 .98250 .98245 .98240 .98234 .98229 .98223 .98218 .98212 .98207 .98201 .98196 .98190 .98185 .98179 .98174 .98168 .98163 .19081 .19109 .19138 .19167 .19195 .19224 .19252 .19281 .19309 .19338 .19366 .19395 .19423 .19452 .19481 .19509 .19538 .19566 .19595 .19623 .19652 .19680 .19709 .19737 .19766 .19794 .19823 .19851 .19880 .19908 .19937 .19965 .19994 .20022 .20051 .20079 .20108 .20136 .20165 .20193 .20222 .20250 .20279 .20307 .20336 .20364 .20393 .20421 .20450 .20478 .20507 .20535 .20563 .20592 .20620 .20649 .20677 .20706 .20734 .20763 .20791 .98163 .98157 .98152 .98146 .98140 .98135 .98129 .98124 .98118 .98112 .98107 .98101 .98096 .98090 .98084 .98079 .98073 .98067 .98061 .98056 .98050 .98044 .98039 .98033 .98027 .98021 .98016 .98010 .98004 .97998 .97992 .97987 .97981 .97975 .97969 .97963 .97958 .97952 .97946 .97940 .97934 .97928 .97922 .97916 .97910 .97905 .97899 .97893 .97887 .97881 .97875 .97869 .97863 .97857 .97851 .97845 .97839 .97833 .97827 .97821 .97815 .20791 .20820 .20848 .20877 .20905 .20933 .20962 .20990 .21019 .21047 .21076 .21104 .21132 .21161 .21189 .21218 .21246 .21275 .21303 .21331 .21360 .21388 .21417 .21445 .21474 .21502 .21530 .21559 .21587 .21616 .21644 .21672 .21701 .21729 .21758 .21786 .21814 .21843 .21871 .21899 .21928 .21956 .21985 .22013 .22041 .22070 .22098 .22126 .22155 .22183 .22212 .22240 .22268 .22297 .22325 .22353 .22382 .22410 .22438 .22467 .22495 .97815 .97809 .97803 .97797 .97791 .97784 .97778 .97772 .97766 .97760 .97754 .97748 .97742 .97735 .97729 .97723 .97717 .97711 .97705 .97698 .97692 .97686 .97680 .97673 .97667 .97661 .97655 .97648 .97642 .97636 .97630 .97623 .97617 .97611 .97604 .97598 .97592 .97585 .97579 .97573 .97566 .97560 .97553 .97547 .97541 .97534 .97528 .97521 .97515 .97508 .97502 .97496 .97489 .97483 .97476 .97470 .97463 .97457 .97450 .97444 .97437 .22495 .22523 .22552 .22580 .22608 .22637 .22665 .22693 .22722 .22750 .22778 .22807 .22835 .22863 .22892 .22920 .22948 .22977 .23005 .23033 .23062 .23090 .23118 .23146 .23175 .23203 .23231 .23260 .23288 .23316 .23345 .23373 .23401 .23429 .23458 .23486 .23514 .23542 .23571 .23599 .23627 .23656 .23684 .23712 .23740 .23769 .23797 .23825 .23853 .23882 .23910 .23938 .23966 .23995 .24023 .24051 .24079 .24108 .24136 .24164 .24192 .97437 .97430 .97424 .97417 .97411 .97404 .97398 .97391 .97384 .97378 .97371 .97365 .97358 .97351 .97345 .97338 .97331 .97325 .97318 .97311 .97304 .97298 .97291 .97284 .97278 .97271 .97264 .97257 .97251 .97244 .97237 .97230 .97223 .97217 .97210 .97203 .97196 .97189 .97182 .97176 .97169 .97162 .97155 .97148 .97141 .97134 .97127 .97120 .97113 .97106 .97100 .97093 .97086 .97079 .97072 .97065 .97058 .97051 .97044 .97037 .97030 .24192 .24220 .24249 .24277 .24305 .24333 .24362 .24390 .24418 .24446 .24474 .24503 .24531 .24559 .24587 .24615 .24644 .24672 .24700 .24728 .24756 .24784 .24813 .24841 .24869 .24897 .24925 .24954 .24982 .25010 .25038 .25066 .25094 .25122 .25151 .25179 .25207 .25235 .25263 .25291 .25320 .25348 .25376 .25404 .25432 .25460 .25488 .25516 .25545 .25573 .25601 .25629 .25657 .25685 .25713 .25741 .25769 .25798 .25826 .25854 .25882 .97030 .97023 .97015 .97008 .97001 .96994 .96987 .96980 .96973 .96966 .96959 .96952 .96945 .96937 .96930 .96923 .96916 .96909 .96902 .96894 .96887 .96880 .96873 .96866 .96858 .96851 .96844 .96837 .96829 .96822 .96815 .96807 .96800 .96793 .96786 .96778 .96771 .96764 .96756 .96749 .96742 .96734 .96727 .96719 .96712 .96705 .96697 .96690 .96682 .96675 .96667 .96660 .96653 .96645 .96638 .96630 .96623 .96615 .96608 .96600 .96593 60 59 58 57 56 55 54 53 52 51 50 49 48 47 46 45 44 43 42 41 40 39 38 37 36 35 34 33 32 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 t Cosine > Sine Cosine ; Sine Cosine : Sine Cosine Sine Cosine i Sine - t 1 79° 78° 77° 76° 75° ... 458 NATURAL SINES AND COSINES , 15 ° 16 ° 17 ° 18 ° | 19 ° / Sine Cosine Sine Cosine Sine Cosine Sine Cosine Sine Cosine 0 .25882 .96593 .27564 .96126 .29237 .95630 .30902 .95106 .32557 .94552 60 1 .25910 .96585 .27592 .96118 .29265 .95622 .30929 .95097 .32584 .94542 59 2 .25938 .96578 .27620 .96110 .29293 .95613 .30957 .95088 .32612 .94533 58 3 .25966 .96570 .27648 .96102 .29321 .95605 .30985 .95079 .32639 .94523 57 4 .25994 .96562 .27676 .96094 .29348 .95596 .31012 .95070 .32667 .94514 56 5 .26022 .96555 .27704 .96086 .29376 .95588 .31040 .95061 .32694 .94504 55 6 .26050 .96547 .27731 .96078 .29404 .95579 .31068 .95052 .32722 .94495 54 7 .26079 .96540 .27759 .96070 .29432 .95571 .31095 .95043 .32749 .94485 53 8 .26107 .96532 .27787 .96062 .29460 .95562 .31123 .95033 .32777 .94476 52 9 .26135 .96524 .27815 .96054 .29487 .95554 .31151 .95024 .32804 .94466 51 10 .26163 .96517 .27843 .96046 .29515 .95545 .31178 .95015 .32832 .94457 50 11 .26191 .96509 .27871 .96037 .29543 .95536 .31206 .95006 .32859 .94447 49 12 .26219 .96502 .27899 .96029 .29571 .95528 .31233 .94997 .32887 .94438 48 13 .26247 .96494 .27927 .96021 .29599 .95519 .31261 .94988 .32914 .94428 47 14 .26275 .96486 .27955 .96013 .29626 .95511 .31289 .94979 .32942 .94418 46 15 .26303 .96479 .27983 .96005 .29654 .95502 .31316 .94970 .32969 .94409 45 16 .26331 .96471 .28011 .95997 .29682 .95493 .31344 .94961 .32997 .94399 44 17 .26359 .96463 .28039 .95989 .29710 .95485 .31372 .94952 .33024 .94390 43 18 .26387 .96456 .28067 .95981 .29737 .95476 .31399 .94943 .33051 .94380 42 19 .26415 .96448 .28095 .95972 .29765 .95467 .31427 .94933 .33079 .94370 41 20 .26443 .96440 .28123 .95964 .29793 .95459 .31454 .94924 .33106 .94361 40 21 .26471 .96433 .28150 .95956 .29821 .95450 .31482 .94915 .33134 .94351 39 22 .26500 .96425 .28178 .95948 .29849 .95441 .31510 .94906 .33161 .94342 38 23 .26528 .96417 .28206 .95940 .29876 .95433 .31537 .94897 .33189 .94332 37 24 .26556 .96410 .28234 .95931 .29904 .95424 .31565 .94888 .33216 .94322 36 25 .26584 .96402 .28262 .95923 .29932 .95415 .31593 .94878 .33244 .94313 35 26 .26612 .96394 .28290 .95915 .29960 .95407 .31620 .94869 .33271 .94303 34 27 .26640 .96386 .28318 .95907 .29987 .95398 .31648 .94860 .33298 .94293 33 28 .26668 .96379 .28346 .95898 .30015 .95389 .31675 .94851 .33326 .94284 32 29 .26696 .96371 .28374 .95890 .30043 .95380 .31703 .94842 .33353 .94274 31 30 .26724 .96363 28402 .95882 .30071 .95372 .31730 .94832 .33381 .94264 30 31 .26752 .96355 .28429 .95874 .30098 .95363 .31758 .94823 .33408 .94254 29 32 .26780 .96347 .28457 .95865 .30126 .95354 .31786 .94814 .33436 .94245 28 33 .26808 .96340 .28485 .95857 .30154 .95345 .31813 .94805 .33463 .94235 27 34 .26836 .96332 .28513 .95849 .30182 .95337 .31841 .94795 .33490 .94225 26 35 .26864 .96324 .28541 .95841 .30209 .95328 .31868 .94786 .33518 .94215 25 36 .26892 .96316 .28569 .95832 .30237 .95319 .31896 .94777 .33545 .94206 24 37 .26920 .96308 .28597 .95824 .30265 .95310 .31923 .94768 .33573 .94196 23 38 .26948 .96301 .28625 .95816 .30292 .95301 .31951 .94758 .33600 .94186 22 39 .26976 .96293 .28652 .95807 .30320 .95293 .31979 .94749 .33627 .94176 21 40 .27004 .96285 .28680 .95799 .30348 .95284 .32006 .94740 .33655 .94167 20 41 .27032 .96277 .28708 .95791 .30376 .95275 .32034 .94730 .33682 .94157 19 42 .27060 .96269 .28736 .95782 .30403 .95266 .32061 .94721 .33710 .94147 18 43 .27088 .96261 .28764 .95774 .30431 .95257 ' .32089 .94712 .33737 .94137 17 44 .27116 .96253 .28792 .95766 .30459 .95248 .32116 .94702 .33764 .94127 16 45 .27144 .96246 .28820 .95757 .30486 .95240 .32144 .94693 .33792 .94118 15 46 .27172 .96238 .28847 .95749 .30514 .95231 .32171 .94684 .33819 .94108 14 47 .27200 .96230 .28875 .95740 .30542 .95222 .32199 .94674 .33846 .94098 13 48 .27228 .96222 .28903 .95732 .30570 .95213 .32227 .94665 .33874 .94088 12 49 .27256 .96214 .28931 .95724 .30597 .95204 .32254 .94656 .33901 .94078 11 50 .27284 .96206 .28959 .95715 .30625 .95195 .32282 .94646 .33929 .94068 10 51 .27312 .96198 .28987 .95707 .30653 .95186 .32309 .94637 .33956 .94058 9 52 .27340 .96190 .29015 .95698 .30680 .95177 .32337 .94627 .33983 .94049 8 53 .27368 .96182 .29042 .95690 .30708 .95168 .32364 .94618 .34011 .94039 7 54 .27396 .96174 .29070 .95681 .30736 .95159 .32392 .94609 .34038 .94029 6 55 .27424 .96166 .29098 .95673 .30763 .95160 .32419 .94599 .34065 .94019 5 56 .27452 .96158 .29126 .95664 .30791 .95142 .32447 .94590 .34093 .94009 4 57 .27480 .96150 .29154 .95656 .30819 .95133 .32474 .94580 .34120 .93999 3 58 .27508 .96142 .29182 .95647 .30846 .95124 .32502 .94571 .34147 .93989 2 59 .27536 .96134 .29209 .95639 .30874 .95115 .32529 .94561 .34175 .93979 1 60 .27564 .96126 .29237 .95630 .30902 .95106 .32557 .94552 .34202 .93969 0 Cosine Sine Cosine Sine Cosine Sine Cosine Sine Cosine Sine / 7 4° 78 ° 72 ° 71 ° 70 ° \ / NATURAL SINES AND COSINES. 459 20° 21° 22° 23° 24° / Sine Cosine Sine Cosine Sine Cosine Sine Cosine Sine Cosine o .34202 .93969 .35837 .93358 .37461 .92718 .39073 .92050 .40674 .91355 60 1 .34229 .93959 .35864 .93348 .37488 .92707 .39100 .92039 .40700 .91343 59 2 .34257 .93949 .35891 .93337 .37515 .92697 .39127 .92028 .40727 .91331 58 3 .34284 .93939 .35918 .93327 .37542 .92686 .39153 .92016 .40753 .91319 57 4 .34311 .93929 .35945 .93316 .37569 .92675 .39180 .92005 .40780 .91307 56 5 .34339 .93919 .35973 .93306 .37595 .92664 .39207 .91994 .40806 .91295 55 6 .34366 .93909 .36000 .93295 .37622 .92653 .39234 .91982 .40833 .91283 54 7 .34393 .93899 .36027 .93285 .37649 .92642 .39260 .91971 .40860 .91272 53 g .34421 .93889 .36054 .93274 .37676 .92631 .39287 .91959 .40886 .91260 52 9 .34448 .93879 .36081 .93264 .37703 .92620 .39314 .91948 .40913 .91248 51 10 .34475 .93869 .36108 .93253 .37730 .92609 .39341 .91936 .40939 .91236 50 11 .34503 .93859 .36135 .93243 .37757 .92598 .39367 .91925 .40966 .91224 49 12 .34530 .93849 .36162 .93232 .37784 .92587 .39394 .91914 .40992 .91212 48 13 .34557 .93839 .36190 .93222 .37811 .92576 .39421 .91902 .41019 .91200 47 14 .34584 .93829 .36217 .93211 .37838 .92565 .39448 .91891 .41045 .91188 46 15 .34612 .93819 .36244 .93201 .37865 .92554 .39474 .91879 .41072 .91176 45 16 .34639 .93809 .36271 .93190 .37892 .92543 .39501 .91868 .41098 .91164 44 17 .34666 .93799 .36298 .93180 .37919 .92532 .39528 .91856 .41125 .91152 43 18 .34694 .93789 .36325 .93169 .37946 .92521 .39555 .91845 .41151 .91140 42 19 .34721 .93779 .36352 .93159 .37973 .92510 .39581 .91833 .41178 .91128 41 20 .$4748 .93769 .36379 .93148 .37999 .92499 .39608 .91822 .41204 .91116 40 21 .34775 .93759 .36406 .93137 .38026 .92488 .39635 .91810 .41231 .91104 39 22 .34803 .93748 .36434 .93127 .38053 .92477 .39661 .91799 .41257 .91092 38 23 *.34830 .93738 .36461 .93116 .38080 .92466 .39688 .91787 .41284 .91080 37 24 .34857 .93728 .36488 .93106 .38107 .92455 .39715 .91775 .41310 .91068 36 25 .34884 .93718 .36515 .93095 .38134 .92444 .39741 .91764 .41337 .91056 35 26 .34912 .93708 .36542 .93084 .38161 .92432 .39768 .91752 .41363 .91044 34 27 .34939 .93698 .36569 .93074 .38188 .92421 .39795 .91741 .41390 .91032 33 28 .34966 .93688 .36596 .93063 .38215 .92410 .39822 .91729 .41416 .91020 32 29 .34993 .93677 .36623 .93052 .38241 .92399 .39848 .91718 .41443 .91008 31 30 .35021 .93667 .36650 .93042 .38268 .92388 .39875 .91706 .41469 .90996 30 31 ' .35048 .93657 .36677 .93031 .38295 .92377 .39902 .91694 .41496 .90984 29 32 .35075 .93647 .36704 .93020 .38322 .92366 .39928 .91683 .41522 .90972 28 33 .35102 .93637 .36731 .93010 .38349 .92355 .39955 .91671 .41549 .90960 27 34 .35130 .93626 .36758 .92999 .38376 .92343 .39982 .91660 .41575 .90948 26 35 .35157 .93616 .36785 .92988 .38403 .92332 .40008 .91648 .41602 .90936 25 36 .35184 .93606 .36812 .92978 .38430 .92321 .40035 .91636 .41628 .90924 24 37 .35211 .93596 .36839 .92967 .38456 .92310 .40062 .91625 .41655 .90911 23 38 .35239 .93585 .36867 *92956 .38483 .92299 .40088 .91613 .41681 .90899 22 39 .35266 .93575 .36894 .92945 .38510 .92287 .40115 .91601 .41707 .90887 21 40 .35293 .93565 .36921 .92935 .38537 .92276 .40141 .91590 .41734 .90875 20 41 .35320 .93555 .36948 .92924 .38564 .92265 .40168 .91578 .41760 .90863 19 42 .35347 .93544 .36975 .92913 .38591 .92254 .40195 .91566 .41787 .90851 18 43 .35375 .93534 .37002 .92902 .38617 .92243 .40221 .91555 .41813 .90839 17 44 .35402 .93524 .37029 .92892 .38644 .92231 .40248 .91543 .41840 .90826 16 45 .35429 .93514 .37056 .92881 .38671 .92220 .40275 .91531 .41866 .90814 15 46 .35456 .93502 .37083 .92870 .38698 .92209 .40301 .91519 .41892 .90802 14 47 .35484 .93493 .37110 .92859 .38725 .92198 .40328 .91508 .41919 .90790 13 48 .35511 .93483 .37137 .92849 .38752 .92186 .40355 .91496 .41945 .90778 12 49 .35538 .93472 .37164 .92838 .38778 .92175 .40381 .91484 .41972 .90766 11 50 .35565 .93462 .37191 .92827 .38805 .92164 .40408 .91472 .41998 .90753 10 51 .35592 .93452 .37218 .92816 .38832 .92152 .40434 .91461 .42024 .90741 9 52 .35619 .93441 .37245 .92805 .38859 .92141 .40461 .91449 .42051 .90729 8 53 .35647 .93431 .37272 .92794 .38886 .92130 .40488 .91437 .42077 .90717 7 54 .35674 .93420 .37299 .92784 .38912 .92119 .40514 .91425 .42104 .90704 6 55 .35701 .93410 .37326 .92773 .38939 .92107 .40541 .91414 .42130 .90692 5 56 .35728 .93400 .37353 .92762 .38966 .92096 .40567 .91402 .42156 .90680 4 57 .35755 .93389 .37380 .92751 .38993 .92085 .40594 .91390 .42183 .90668 3 58 .35782 .93379 .37407 .92740 .39020 .92073 .40621 .91378 .42209 .90655 2 59 .35810 .93368 .37434 .92729 .39046 .92062 .40647 .91366 .42235 .90643 1 60 .35837 .93358 .37461 .92718 .39073 .92050 .40674 .91355 .42262 .90631 0 Cosine Sine Cosine Sine Cosine Sine Cosine Sine Cosine Sine I 69° 68° 67° 66° 65° f 460 natural sines and cosines. 25 ° 26 ° 27 ° 28 ° 29 ° / I - Sine Cosine Sine Cosine Sine Cosine Sine Cosine Sine Cosine 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 87 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 .42262 .42288 .42315 .42341 .42367 .42394 .42420 .42446 .42473 .42499 .42525 .42552 .42578 .42604 .42631 .42657 .42683 .42709 .42736 .42762 .42788 .42815 .42841 .42867 .42894 .42920 .42946 .42972 .42999 .43025 .43051 .43077 .43104 .43130 .43156 .43182 .43209 .43235 .43261 .43287 .43313 .43340 .43366 .43392 .43418 .43445 .43471 .43497 .43523 .43549 .43575 .43602 .43628 .43654 .43680 .43706 .43733 .43759 .43785 .43811 .43837 .90631 .90618 .90606 .90594 .90582 .90569 .90557 .90545 .90532 .90520 .90507 .90495 .90483 .90470 .90458 .90446 .90433 .90421 .90408 .90396 .90383 .90371 .90358 .90346 .90334 .90321 .90309 .90296 .90284 .90271 .90259 .90246 .90233 .90221 .90208 .90196 .90183 .90171 .90158 .90146 .90133 .90120 .90108 .90095 .90082 .90070 .90057 .90045 .90032 .90019 .90007 .89994 .89981 .89968 .89956 .89943 .89930 .89918 .89905 .89892 .89879 .43837 .43863 .43889 .43916 .43942 .43968 .43994 .44020 .44046 .44072 .44098 .44124 .44151 .44177 .44203 .44229 .44255 .44281 .44307 .44333 .44359 .44385 .44411 .44437 .44464 .44490 .44516 .44542 .44568 .44594 .44620 .44646 .44672 .44698 .44724 .44750 .44776 .44802 .44828 .44854 .44880 .44906 .44932 .44958 .44984 .45010 .45036 .45062 .45088 .45114 .45140 .45166 .45192 .45218 .45243 .45269 .45295 .45321 .45347 .45373 .45399 .89879 .89867 .89854 .89841 .89828 .89816 .89803 .89790 .89777 .89764 .89752 .89739 .89726 .89713 .89700 .89687 .89674 .89662 .89649 .89636 .89623 .89610 .89597 .89584 .89571 .89558 .89545 .89532 .89519 .89506 .89493 .89480 .89467 .89454 .89441 .89428 .89415 .89402 .89389 .89376 .89363 .89350 .89337 .89324 .89311 .89298 .89285 .89272 .89259 .89245 .89232 .89219 .89206 .89193 .89180 .89167 .89153 .89140 .89127 .89114 .89101 .45399 .45425 .45451 .45477 .45503 .45529 .45554 .45580 .45606 .45632 .45658 .45684 .45710 .45736 .45762 | .45787 .45813 | .45839 | .45865 .45891 : .45917 j .45942 .45968 .45994 .46020 .46046 .46072 ! .46097 .46123 .46149 | .46175 .46201 ! .46226 .46252 .46278 .46304 .46330 .46355 .46381 .46407 .46433 .46458 .46484 .46510 .46536 .46561 .46587 .46613 .46639 .46664 .46690 .46716 .46742 .46767 .46793 .46819 .46844 .46870 .46896 .46921 .46947 .89101 .89087 .89074 .89061 .89048 .89035 .89021 .89008 .88995 .88981 .88968 .88955 .88942 .88928 .88915 .88902 .88888 .88875 .88862 .88848 .88835 .88822 .88808 .88795 .88782 .88768 .88755 .88741 .88728 .88715 .88701 ! .88688 .88674 | .88661 i .88647 ! .88634 .88620 .88607 1 .88593 .88580 .88566 .88553 .88539 ! .88526 .88512 ! .88499 ! .88485 1 .88472 1 .88458 1 .88445 : .88431 ! .88417 1 .88404 i .88390 I .88377 1 .88363 ' .88349 .88336 ! .88322 | .88308 .88295 .46947 .46973 .46999 .47024 .47050 .47076 .47101 .47127 .47153 .47178 .47204 .47229 .47255 .47281 .47306 .47332 .47358 .47383 .47409 .47434 .47460 .47486 .47511 .47537 .47562 .47588 .47614 .47639 .47665 .47690 .47716 .47741 .47767 .47793 .47818 .47844 .47869 .47895 .47920 .47946 .47971 .47997 .48022 .48048 .48073 .48099 .48124 .48150 .48175 .48201 .48226 .48252 .48277 .48303 .48328 .48354 .48379 .48405 .48430 .48456 .48481 .88295 .88281 .88267 .88254 .88240 .88226 .88213 .88199 .88185 .88172 .88158 .88144 .88130 .88117 .88103 .88089 .88075 .88062 .88048 .88034 .88020 .88006 .87993 .87979 .87965 .87951 .87937 .87923 .87909 .87896 .87882 .87868 .87854 .87840 .87826 .87812 .87798 .87784 .87770 .87756 .87743 .87729 .87715 .87701 .87687 .87673 .87659 .87645 .87631 .87617 .87603 .87589 .87575 .87561 .87546 .87532 .87518 .87504 .87490 .87476 .87462 .48481 .48506 .48532 .48557 .48583 .48608 .48634 ! .48659 j .48684 | .48710 .48735 .48761 .48786 .48811 .48837 .48862 .48888 .48913 .48938 .48964 | .48989 .49014 .49040 .49065 .49090 .49116 .49141 .49166 .49192 .49217 .49242 .49268 .49293 .49318 .49344 .49369 .49394 .49419 .49445 .49470 .49495 .49521 .49546 .49571 .49596 .49622 .49647 .49672 .49697 .49723 .49748 .49773 .49798 .49824 .49849 .49874 .49899 .49924 .49950 .49975 .50000 .87462 .87448 .87434 .87420 .87406 .87391 .87377 .87363 .87349 .87335 .87321 .87306 .87292 .87278 .87264 .87250 .87235 .87221 .87207 .87193 .87178 .87164 .87150 .87136 .87121 .87107 .87093 .87079 .87064 .87050 .87036 .87021 .87007 .86993 .86978 .86964 .86949 .86935 .86921 .86906 .86892 .86878 .86863 .86849 .86834 .86820 .86805 .86791 .86777 .86762 .86748 ,.86733 .86719 .86704 .86690 .86675 .86661 .86646 .86632 .86617 .86603 60 59 58 57 56 55 54 53 52 51 50 49 48 47 46 45 44 43 42 41 40 39 38 37 36 35 34 33 32 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 Cosine Sine Cosine | Sine Cosine Sine Cosine Sine Cosine Sine / / 64 ° 63 ° 62 ° 61 ° 60 ° NATURAL SINES AND COSINES. 461 30° 31° 32° 33° 34° / t Sine Cosine Sine Cosine Sine Cosine Sine Cosine Sine Cosine 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 .50000 .50025 .50050 .50076 .50101 .50126 .50151 .50176 .50201 .50227 .50252 .50277 .50302 .50327 .50352 .50377 .50403 .50428 .50453 .50478 .50503 .50528 .50553 .50578 .50603 .50628 .50654 .50679 .50704 .50729 .50754 .50779 .50804 .50829 .50854 .50879 .50904 .50929 .50954 .50979 .51004 .51029 .51054 .51079 .51104 .51129 .51154 .51179 .51204 .51229 .51254 .51279 .51304 .51329 .51354 .51379 .51404 .51429 .51454 .51479 .51504 .86603 .86588 .86573 .86559 .86544 .86530 .86515 .86501 .86486 .86471 .86457 .86442 .86427 .86413 .86398 .86384 .86369 .86354 .86340 .86325 .86310 .86295 .86281 .86266 .86251 .86237 .86222 .86207 .86192 .86178 .86163 .86148 .86133 .86119 .86104 .86089 .86074 .86059 .86045 .86030 .86015 .86000 .85985 .85970 .85956 .85941 .85926 .85911 .85896 .85881 .85866 .85851 .85836 .85821 .85806 .85792 .85777 .85762 .85747 .85732 .85717 .51504 .51529 .51554 .51579 .51604 .51628 .51653 .51678 .51703 .51728 .51753 .51778 .51803 .51828 .51852 .51877 .51902 .51927 .51952 .51977 .52002 .52026 .52051 .52076 .52101 .52126 .52151 .52175 .52200 .52225 .52250 .52275 .52299 .52324 .52349 .52374 .52399 .52423 .52448 .52473 .52498 .52522 .52547 .52572 .52597 .52621 .52646 .52671 .52696 .52720 .52745 .52770 .52794 .52819 .52844 .52869 .52893 .52918 .52943 .52967 .52992 .85717 .85702 .85687 .85672 .85657 .85642 .85627 .85612 .85597 .85582 .85567 .85551 .85536 .85521 .85506 .85491 .85476 .85461 .85446 .85431 .85416 .85401 .85385 .85370 .85355 .85340 .85325 .85310 .85294 .85279 .85264 .85249 .85234 .85218 .85203 .85188 .85173 .85157 .85142 .85127 .85112 .85096 .85081 .85066 .85051 .85035 .85020 .85005 .84989 .84974 .84959 .84943 .84928 .84913 .84897 .84882 .84866 .84851 .84836 .84820 .84805 .52992 .53017 .53041 .53066 .53091 .53115 .53140 .53164 .53189 .53214 .53238 .53263 .53288 .53312 .53337 .53361 .53386 .53411 .53435 .53460 .53484 .53509 .53534 .53558 .53583 .53607 .53632 .53656 .53681 .53705 .53730 .53754 .53779 .53804 .53828 .53853 . .53877 .53902 .53926 .53951 .53975 .54000 .54024 .54049 .54073 .54097 .54122 .54146 .54171 .54195 .54220 .54244 .54269 .54293 .54317 .54342 .54366 .54391 .54415 .54440 .54464 .84805 .84789 .84774 .84759 .84743 .84728 .84712 .84697 .84681 .84666 .84650 .84635 .84619 .84604 .84588 .84573 .84557 .84542 .84526 .84511 .84495 .84480 .84464 .84448 .84433 .84417 .84402 .84386 .84370 .84355 .84339 .84324 .84308 .84292 .84277 .84261 .84245 .84230 .84214 .84198 .84182 .84167 .84151 .84135 .84120 .84104 .84088 .84072 .84057 .84041 .84025 .84009 .83994 .83978 .83962 .83946 .83930 .83915 .83899 .83883 .83867 .54464 .54488 .54513 .54537 .54561 .54586 .54610 .54635 .54659 .54683 .54708 .54732 .54756 .54781 .54805 .54829 .54854 .54878 .54902 .54927 .54951 .54975 .54999 .55024 .55048 .55072 .55097 .55121 .55145 .55169 .55194 .55218 .55242 .55266 .55291 .55315 .55339 .55363 .55388 .55412 .55436 .55460 .55484 .55509 .55533 .55557 .55581 .55605 .55630 .55654 .55678 .55702 .55726 .55750 .55775 .55799 .55823 .55847 .55871 .55895 .55919 .83867 .83851 .83835 .83819 .83804 .83788 .83772 .83756 .83740 .83724 .83708 .83692 .83676 .83660 .83645 .83629 .83613 .83597 .83581 .83565 .83549 .83533 .83517 .83501 .83485 .83469 .83453 .83437 .83421 .83405 .83389 .83373 .83356 .83340 .83324 .83308 .83292 .83276 .83260 .83244 .83228 .83212 .83195 .83179 .83163 .83147 .83131 .83115 .83098 .83082 .83066 .83050 .83034 .83017 .83001 .82985 .82969 .82953 .82936 .82920 .82904 .55919 .55943 .55968 .55992 .56016 .56040 .56064 .56088 .56112 .56136 .56160 .56184 .56208 .56232 .50256 .56280 .56305 .56329 .56353 .56377 .56401 .56425 .56449 .56473 .56497 .56521 .56545 .56569 .56593 .56617 .56641 .56665 .56689 .56713 .56736 .56760 .56784 .56808 .56832 .56856 .56880 .56904 .56928 .56952 .56976 .57000 .57024 .57047 .57071 .57095 .57119 .57143 .57167 .57191 .57215 .57238 .57262 .57286 .57310 .57334 .57358 .82904 .82887 .82871 .82855 .82839 .82822 .82806 .82790 .82773 .82757 .82741 .82724 .82708 .82692 .82675 .82659 .82643 .82626 .82610 .82593 .82577 .82561 .82544 .82528 .82511 .82495 .82478 .82462 .82446 .82429 .82413 .82396 .82380 .82363 .82347 .82330 .82314 .82297 .82281 .82264 .82248 .82231 .82214 .82198 .82181 .82165 .82148 .82132 .82115 .82098 .82082 .82065 .82048 .82032 .82015 .81999 .81982 .81965 .81949 .81932 .81915 60 59 58 57 56 55 54 53 52 51 50 49 48 47 46 45 44 43 42 41 40 39 38 37 36 35 34 33 32 31 30 29 28 27 26 25 24 23 22 21 , 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 / Cosine i Sine Cosine Sine Cosine Sine Cosine Sine Cosine Sine 59° 58° i 57° 56° 55° f 462 NATURAL SINES AND COSINES. 35 ° 36 ° 37 ° 38 ° 39 ° f Sine Cosine Sine Cosine Sine Cosine Sine Cosine Sine Cosine 0 .57358 .81915 .58779 .80902 .60182 .79864 .61566 .78801 .62932 .77715 60 1 .57381 .81899 .58802 .80885 .60205 .79846 .61589 .78783 .62955 .77696 59 2 .57405 .81882 .58826 .80867 .60228 .79829 .61612 .78765 .62977 .77678 58 3 .57429 .81865 .58849 .80850 .60251 .79811 .61635 .78747 .63000 .77660 57 4 .57453 .81848 .58873 .80833 .60274 .79793 .61658 .78729 .63022 .77641 56 5 .57477 .81832 .58896 .80816 .60298 .79776 .61681 .78711 .63045 .77623 55 6 .57501 .81815 .58920 .80799 .60321 .79758 .61704 .78694 .63068 .77605 54 7 .57524 .81798 .58943 .80782 .60344 .79741 .61726 .78676 .63090 .77586 53 8 .57548 .81782 .58967 .80765 .60367 .79723 .61749 .78658 .63113 .77568 52 9 .57572 .81765 .58990 .80748 .60390 .79706 .61772 .78640 .63135 .77550 51 10 .57596 .81748 .59014 .80730 .60414 .79688 .61795 .78622 .63158 .77531 50 11 .57619 .81731 .59037 .80713 .60437 .79671 .61818 .78604 .63180 .77513 49 12 .57643 .81714 .59061 .80696 .60460 .79653 .61841 .78586 .63203 .77494 48 13 .57667 .81698 .59084 .80679 .60483 .79635 .61864 .78568 .63225 .77476 47 14 .57691 .81681 .59108 .80662 .60506 .79618 .61887 .78550 .63248 .77458 46 15 .57715 .81664 .59131 .80644 .60529 .79600 .61909 .78532 .63271 .77439 45 16 .57738 .81647 .59154 .80627 .60553 .79583 .61932 .78514 .63293 .77421 44 17 .57762 .81631 .59178 .80610 .60576 .79565 .61955 .78496 .63316 .77402 43 18 .57786 .81614 .59201 .80593 .60599 .79547 .61978 .78478 .63338 .77384 42 19 .57810 .81597 .59225 .80576 .60622 .79530 .62001 .78460 .63361 .77366 41 20 .57833 .81580 .59248 .80558 .60645 .79512 .62024 .78442 .63383 .77347 40 21 .57857 .81563 .59272 .80541 .60668 .79494 .62046 .78424 .63406 .77329 39 22 .57881 .81546 .59295 .80524 .60691 .79477 .62069 .78405 .63428 .77310 38 23 .57904 .81530 .59318 .80507 .60714 .79459 .62092 .78387 .63451 .77292 37 24 .57928 .81513 .59342 .80489 .60738 .79441 .62115 .78369 .63473 .77273 36 25 .57952 .81496 .59365 .80472 .60761 .79424 .62138 .78351 .63496 .77255 35 26 .57976 .81479 .59389 .80455 .60784 .79406 .62160 .78333 .63518 .77236 34 27 .57999 .81462 .59412 .80438 .60807 .79388 .62183 .78315 .63540 .77218 33 28 .58023 .81445 .59436 .80420 .60830 .79371 .62206 .78297 .63563 .77199 32 29 .58047 .81428 .59459 .80403 .60853 .79353 .62229 .78279 .63585 .77181 31 30 .58070 .81412 .59482 .80386 .60876 .79335 .62251 .78261 .63608 .77162 30 31 .58094 .81395 .59506 .80368 .60899 .79318 .62274 .78243 .63630 .77144 29 32 .58118 .81378 .59529 .80351 .60922 .79300 .62297 .78225 .63653 .77125 28 33 .58141 .81361 .59552 .80334 .60945 .79282 .62320 .78206 .63675 .77107 27 34 .58165 .81344 .59576 .80316 .60968 .79264 .62342 .78188 .63698 .77088 26 35 .58189 .81327 .59599 .80299 .60991 .79247 .62365 .78170 .63720 .77070 25 36 .58212 .81310 .59622 .80282 .61015 .79229 .62388 .78152 .63742 .77051 24 37 .58236 .81293 .59646 .80264 .61038 .79211 .62411 .78134 .63765 .77033 23 38 .58260 .81276 .59669 .80247 .61061 .79193 .62433 .78116 .63787 .77014 22 39 .58283 .81259 .59693 .80230 .61084 .79176 .62456 .78098 .63810 .76996 21 40 .58307 .81242 .59716 .80212 .61107 .79158 .62479 .78079 .63832 .76977 20 41 .58330 .81225 .59739 .80195 .61130 .79140 .62502 .78061 .63854 .76959 19 42 .58354 .81208 .59763 .80178 .61153 .79122 .62524 .78043 .63877 .76940 18 43 .58378 .81191 .59786 .80160 .61176 .79105 .62547 .78025 .63899 .76921 17 44 .58401 .81174 .59809 .80143 .61199 .79087 .62570 .78007 .63922 .76903 16 45 .58425 .81157 .59832 .80125 .61222 .79069 .62592 .77988 .63944 .76884 15 46 .58449 .81140 .59856 .80108 .61245 .79051 .62615 .77970 .63966 .76866 14 47 .58472 .81123 .59879 .80091 .61268 .79033 .62638 .77952 .63989 .76847 13 48 .58496 .81106 .59902 .80073 .61291 .79016 .62660 .77934 .64011 .76828 12 49 .58519 .§1089 .59926 .80056 .61314 .78998 .62683 .77916 .64033 .76810 11 50 .58543 .81072 .59949 .80038 .61337 .78980 .62706 .77897 .64056 .76791 10 51 .58567 .81055 .59972 .80021 .61360 .78962 .62728 .77879 ■ .64078 .76772 9 52 .58590 .81038 .59995 .80003 .61383 .78944 .62751 .77861 .64100 .76754 8 53 .58614 .81021 .60019 .79986 .61406 .78926 .62774 .77843 .64123 .76735 7 54 .58637 .81004 .60042 .79968 .61429 .78908 .62796 .77824 .64145 .76717 6 55 .58661 .80978 .60065 .79951 .61451 .78891 .62819 .77806 .64167 .76698 5 56 .58684 .80970 .60089 .79934 .61474 .78873 .62842 .77788 .64190 .76679 4 57 .58708 .80953 .60112 .79916 .61497 .78855 .62864 .77769 .64212 .76661 3 58 .58731 .80936 .60135 .79899 .61520 .78837 .62887 .77751 .64234 .76642 2 59 .58755 .80919 .60158 .79881 .61543 .78819 .62909 .77733 .64256 .76623 1 60 .58779 .80902 .60182 .79864 .61566 .78801 .62932 .77715 .64279 .76604 0 Cosine Sine Cosine Sine Cosine Sine Cosine Sine Cosine Sine / 54 ° ; 53 ° 52 ° 51 ° 50 ° / NATURAL SINES AND COSINES. 463 40° 41° 42° 43° 44° / / - Sine Cosine Sine Cosine Sine Cosine Sine Cosine Sine i Cosine 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 . 49 50 51 52 53 54 55 56 57 58 59 60 .64279 .64301 .64323 .64346 .64368 .64390 .64412 .64435 .64457 .64479 .64501 .64524 .64546 .64568 .64590 .64612 .64635 .64657 .64679 .64701 .64723 .64746 .64768 .64790 .64812 .64834 .64856 .64878 .64901 .64923 .64945 .64967 .64989 .65011 .65033 .65055 .65077 .65100 .65122 .65144 .65166 .65188 .65210 .65232 .65254 .65276 .65298 .65320 .65342 .65364 .65386 .65408 .65430 .65452 .65474 .65496 .65518 .65540 .65562 .65584 .65606 .76604 .76586 .76567 .76548 .76530 .76511 .76492 .76473 .76455 .76436 .76417 .76398 .76380 .76361 .76342 .76323 .76304 .76286 .76267 .76248 .76229 .76210 .76192 .76173 .76154 .76135 .76116 .76097 .76078 .76059 .76041 .76022 .76003 .75984 .75965 .75946 .75927 .75908 .75889 .75870 .75851 .75832 .75813 .75794 .75775 .75756 .75738 .75719 .75700 .75680 .75661 .75642 .75623 .75604 .75585 .75566 .75547 .75528 .75509 .75490 .75471 .65606 .65628 .65650 .65672 .65694 .65716 .65738 .65759 .65781 .65803 .65825 ' .65847 .65869 .65891 .65913 .65935 .65956 .65978 .66000 .66022 .66044 .66066 .66088 .66109 .66131 .66153 .66175 .66197 .66218 .66240 .66262 .66284 .66306 .66327 .66349 .66371 .66393 .66414 .66436 .66458 .66480 .66501 .66523 .66545 .66566 .66588 .66610 .66632 .66653 .66675 - .66697 .66718 .66740 .66762 .66783 .66805 .66827 .66848 .66870 .66891 .66913 .75471 .75452 .75433 .75414 .75395 .75375 .75356 .75337 .75318 .75299 .75280 .75261 .75241 .75222 .75203 .75184 .75165 .75146 .75126 .75107 .75088 .75069 .75050 .75030 .75011 .74992 .74973 .74953 .74934 .74915 .74896 .74876 .74857 .74838 .74818 .74799 .74780 .74760 .74741 .74722 .74703 .74683 .74664 .74644 .74625 .74606 .74586 .74567 .74548 .74528 .74509 .74489 .74470 .74451 .74431 .74412 .74392 .74373 .74353 .74334 .74314 .66913 .66935 .66956 .66978 .66999 .67021 .67043 .67064 .67086 .67107 .67129 .67151 .67172 .67194 .67215 .67237 .67258 .67280 .67301 .67323 .67344 .67366 .67387 .67409 .67430 .67452 .67473 .67495 .67516 .67538 .67559 .67580 .67602 .67623 .67645 .67666 .67688 .67709 .67730 .67752 .67773 .67795 .67816 .67837 .67859 .67880 .67901 .67923 .67944 .67965 .67987 .68008 .68029 .68051 .68072 .68093 .68115 .68136 .68157 .68179 .68200 .74314 .74295 .74276 .74256 .74237 .74217 .74198 .74178 .74159 .74139 .74120 .74100 .74080 .74061 .74041 .74022 .74002 .73983 .73963 .73944 .73924 .73904 .73885 .73865 .73846 .73826 .73806 .73787 .73767 .73747 .73728 .73708 .73688 .73669 .73649 .73629 .73610 .73590 .73570 .73551 .73531 .73511 .73491 .73472 .73452 .73432 .73413 .73393 .73373 .73353 .73333 .73314 .73294 .73274 .73254 .73234 .73215 .73195 .73175 .73155 .73135 .68200 .68221 .68242 .68264 .68285 .68306 .68327 .68349 .68370 .68391 .68412 .68434 .68455 .68476 .68497 .68518 .68539 .68561 .68582 .68603 .68624 .68645 .68666 .68688 .68709 .68730 .68751 .68772 .68793 .68814 .68835 .68857 .68878 .68899 .68920 .68941 .68962 .68983 .69004 .69025 .69046 .69067 .69088 .69109 .69130 .69151 .69172 .69193 .69214 .69235 .69256 .69277 .69298 .69319 .69340 .69361 .69382 .69403 .69424 .69445 .69466 .73135 .73116 .73096 .73076 .73056 .73036 .73016 .72996 .72976 .72957 .72937 .72917 .72897 .72877 .72857 .72837 .72817 .72797 .72777 .72757 .72737 .72717 .72697 .72677 .72657 .72637 .72617 .72597 .72577 .72557 .72537 .72517 .72497 .72477 .72457 .72437 .72417 .72397 .72377 .72357 .72337 .72317 .72297 .72277 .72257 .72236 .72216 .72196 .72176 .72156 .72136 .72116 .72095 .72075 .72055 .72035 .72015 .71995 .71974 .71954 .71934 .69466 .69487 .69508 .69529 .69549 .69570 .69591 .69612 .69633 .69654 .69675 .69696 .69717 .69737 .69758 .69779 .69800 .69821 .69842 .69862 .69883 .69904 .69925 .69946 .69966 .69987 .70008 .70029 .70049 .70070 .70091 .70112 .70132 .70153 .70174 .70195 .70215 .70236 .70257 .70277 .70298 .70319 .70339 .70360 .70381 .70401 .70422 .70443 .70463 .70484 .70505 .70525 .70546 .70567 .70587 .70608 .70628 .70649 .70670 .70690 .70711 .71934 .71914 .71894 .71873 .71853 .71833 .71813 .71792 .71772 .71752 .71732 .71711 .71691 .71671 .71650 .71630 .71610 .71590 .71569 .71549 .71529 .71508 .71488 .71468 .71447 .71427 .71407 .71386 .71366 .71345 .71325 .71305 .71284 .71264 .71243 .71223 .71203 .71182 .71162 .71141 .71121 .71100 .71080 .71059 .71039 .71019 .70998 .70978 .70957 .70937 .70916 .70896 .70875 .70855 .70834 .70813 .70793 .70772 .70752 .70731 .70711 60 59 58 57 56 55 54 53 52 51 50 49 48 47 46 45 44 43 42 41 40 39 38 37 36 35 34 33 32 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9 8 T 6 5 4 3 2 1 0 / Cosine s Sine 1 Cosine } Sine Cosine : Sine Cosine ; Sine Cosine ! Sine r 49° 48° 47° 46° 45° 464 NATURAL TANGENTS AND COTANGENTS. 0 ° 1 ° 2 ° 3 ° 4 ° Tang Cotang Tang Cotang Tang Cotang Tang Cotang Tang Cotang 0 .00000 Infin. .01746 57.2900 .03492 28.6363 .05241 19.0811 .06993 14.3007 60 1 .00029 3437.75 .01775 56.3506 .03521 28.3994 .05270 18.9755 .07022 14.2411 59 2 .00058 1718.87 .01804 55.4415 .03550 28.1664 .05299 18.8711 .07051 14.1821 58 3 .00087 1145.92 .01833 54.5613 .03579 27.9372 .05328 18.7678 .07080 14.1235 57 4 .00116 859.436 .01862 53.7086 .03609 27.7117 .05357 18.6656 .07110 14.0655 56 5 .00145 687.549 .01891 52.8821 .03638 27.4899 .05387 18.5645 .07139 14.0079 55 6 .00175 572.957 .01920 52.0807 .03667 27.2715 .05416 18.4645 .07168 13.9507 54 7 .00204 491.106 .01949 51.3032 .03696 27.0566 .05445 18.3655 .07197 13.8940 53 8 .00233 429.718 .01978 50.5485 .03725 26.8450 .05474 18.2677 .07227 13.8378 52 9 .00262 381.971 .02007 49.8157 .03754 26.6367 .05503 18.1708 .07256 13.7821 51 10 .00291 343.774 .02036 49.1039 .03783 26.4316 .05533 18.0750 .07285 13.7267 50 11 .00320 312.521 .02066 48.4121 .03812 26.2296 .05562 17.9802 .07314 13.6719 49 12 .00349 286.478 .02095 47.7395 .03842 26.0307 .05591 17.8863 .07344 13.6174 48 13 .00378 264.441 .02124 47.0853 .03871 25.8348 .05620 17.7934 .07373 13.5634 47 14 .00407 245.552 .02153 46.4489 .03900 25.6418 .05649 17.7015 .07402 13.5098 46 15 .00436 229.182 .02182 45.8294 .03929 25.4517 .05678 17.6106 .07431 13.4566 45 16 .00465 214.858 .02211 45.2261 .03958 25.2644 .05708 17.5205 .07461 13.4039 44 17 .00495 202.219 .02240 44.6386 .03987 25.0798 .05737 17.4314 .07490 13.3515 43 18 .00524 190.984 .02269 44.0661 .04016 24.8978 .05766 17.3432 .07519 13.2996 42 19 .00553 180.932 .02298 43 5081 .04046 24.7185 .05795 17.2558 .07548 13.2480 41 20 .00582 171.885 .02328 42.9641 .04075 24.5418 .05824 17.1693 .07578 13.1969 40 21 .00611 163.700 .02357 42.4335 .04104 24.3675 .05854 17.0837 .07607 13.1461 39 22 .00640 156.259 .02386 41.9158 .04133 24.1957 .05883 16.9990 .07636 13.0958 38 23 .00669 149.465 .02415 41.4106 .04162 24.0263 .05912 16.9150 .07665 13.0458 37 24 .00698 143.237 .02444 40.9174 .04191 23.8593 .05941 16.8319 .07695 12.9962 36 25 .00727 137.507 .02473 40.4358 .04220 23.6945 .05970 16.7496 .07724 12.9469 35 26 .00756 132.219 .02502 39.9655 .04250 23.5321 .05999 16.6681 .07753 12.8981 34 27 .00785 127.321 .02531 39.5059 .04279 23.3718 .06029 16.5874 .07782 12.8496 33 28 .00815 122.774 .02560 39.0568 .04308 23.2137 .06058 16.5075 .07812 12.8014 32 29 .00844 118.540 .02589 38.6177 .04337 23.0577 .06087 16.4283 .07841 12.7536 31 30 .00873 114.589 .02619 38.1885 .04366 22.9038 .06116 16.3499 .07870 12.7062 30 31 .00902 110.892 .02648 37.7686 .04395 22.7519 .06145 16.2722 .07899 12.6591 29 32 .00931 107.426 .02677 37.3579 .04424 22.6020 .06175 16.1952 .07929 12.6124 28 33 .00960 104.171 .02706 36.9560 .04454 22.4541 .06204 16.1190 .07958 12.5660 27 34 .00989 101.107 .02735 36.5627 .04483 22.3081 .06233 16.0435 .07987 12.5199 26 35 .01018 98.2179 .02764 36.1776 .04512 22.1640 .06262 15.9687 .08017 12.4742 25 36 .01047 95.4895 .02793 35.8006 .04541 22.0217 .06291 15.8945 .08046 12.4288 24 37 .01076 92.9085 .02822 35.4313 .04570 21.8813 .06321 15.8211 .08075 12.3838 23 38 .01105 90.4633 .02851 35.0695 .04599 21.7426 .06350 15.7483 .08104 12.3390 22 39 .01135 88.1438 .02881 34.7151 .04628 21.6056 .06379 15.6762 .08134 12.2946 21 40 .01164 85.9398 .02910 34.3678 .04658 21.4704 .06408 15.6048 .08163 12.2505 20 41 .01193 83.8435 .02939 34.0273 .04687 21.3369 .06437 15.5340 .08192 12.2067 19 42 .01222 81.8470 .02968 33.6935 .04716 21,2049 .06467 15.4638 .08221 12.1632 18 43 .01251 79.9434 .02997 33.3662 .04745 21.0747 .06496 15.3943 .08251 12.1201 17 44 .01280 78.1263 .03026 33.0452 .04774 20.9460 .06525 15.3254 .08280 12.0772 16 45 .01309 76.3900 .03055 32.7303 .04803 20.8188 .06554 15.2571 .08309 12.0346 15 46 .01338 74.7292 .03084 32.4213 .04833 20.6932 .06584 15.1893 .08339 11.9923 14 47 .01367 73.1390 .03114 32.1181 .04862 20 5691 .06613 15.1222 .08368 11.9504 13 48 .01396 71.6151 .03143 31.8205 .04891 20.4465 .06642 15.0557 .08397 11.9087 12 49 .01425 70.1533 .03172 31.5284 .04920 20.3253 .06671 14.9898 .08427 11.8673 11 50 .01455 68.7501 .03201 31.2416 .04949 20.2056 .06700 14.9244 .08456 11.8262 10 51 .01484 67.4019 .03230 30.9599 .04978 20.0872 .06730 14.8596 .08485 11.7853 9 52 .01513 66.1055 .03259 30.6833 .05007 19.9702 .06759 14.7954 .08514 11.7448 8 53 .01542 64.8580 .03288 30.4116 .05037 19.8546 .06788 14.7317 .08544 11.7045 7 54 .01571 63.6567 .03317 30.1446 .05066 19.7403 .06817 14.6685 .08573 11.6645 6 55 .01600 62.4992 .03346 29.8823 .05095 19.6273 .06847 14.6059 .08602 11.6248 5 56 .01629 61.3829 .03376 29.6245 .05124 19.5156 .06876 14.5438 .08632 11.5853 4 57 .01658 60.3058 .03405 29.3711 .05153 19.4051 .06905 14.4823 .08661 11.5461 3 58 .01687 59.2659 .03434 29.1220 .05182 19.2959 .06934 14.4212 .08690 11.5072 2 59 .01716 58.2612 .03463 28.8771 .05212 19.1879 .06963 14.3607 .08720 11.4685 1 60 .01746 57.2900 .03492 28.6363 .05241 19.0811 .06993 14.3007 .08749 11.4301 0 Cotang Tang Cotang Tang Cotang Tang Cotang 1 Tang Cotang Tang 89 ° 88 ° 87 ° 86 ° 85 ° / NATURAL TANGENTS AND COTANGENTS. 465 5 ° 6 ° 7 ° 8 ° 9 ° / f Tang Cotang Tang Cotang Tang Cotang Tang Cotang Tang Cotang 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 .08749 .08778 .08807 .08837 .08866 .08895 .08925 .08954 .08983 .09013 .09042 .09071 .09101 .09130 .09159 .09189 .09218 .09247 .09277 .09306 .09335 .09365 .09394 .09423 .09453 .09482 .09511 .09541 .09570 .09600 .09629 .09658 .09688 .09717 .09746 .09776 .09805 .09834 .09864 .09893 .09923 .09952 .09981 .10011 .10040 .10069 .10099 .10128 .10158 .10187 .10216 .10246 .10275 .10305 .10334 .10363 .10393 .10422 .10452 .10481 .10510 11.4301 11.3919 11.3540 11.3163 11.2789 11.2417 11 .2048 11.1681 11.1316 11.0954 11.0594 11.0237 10.9882 10.9529 10.9178 10.8829 10.8483 10.8139 10.7797 10.7457 10.7119 10.6783 10.6450 10.6118 10.5789 10.5462 10.5136 10.4813 10.4491 10.4172 10.3854 10.3538 10.3224 10.2913 10.2602 10.2294 10.1988 10.1683 10.1381 10.1080 10.0780 10.0483 10.0187 9.98931 9.96007 9.93101 9.90211 9.87338 9.84482 9.81641 9.78817 9.76009 9.73217 9.70441 9.67680 9.64935 9.62205 9.59490 9.56791 9.54106 9.51436 .10510 .10540 .10569 .10599 .10628 .10657 .10687 .10716 .10746 .10775 .10805 .10834 .10863 .10893 .10922 .10952 .10981 .11011 .11040 .11070 .11099 .11128 .11158 .11187 .11217 .11246 .11276 .11305 .11335 .11364 .11394 .11423 .11452 .11482 .11511 .11541 .11570 .11600 .11629 .11659 .11688 .11718 .11747 .11777 .11806 .11836 .11865 .11895 .11924 .11954 .11983 .12013 .12042 .12072 .12101 .12131 .12160 .12190 .12219 .12249 .12278 9.51436 9.48781 9.46141 9.43515 9.40904 9.38307 9.35724 9.33155 9.30599 9.28058 9.25530 9.23016 9.20516 9.18028 9.15554 9.13093 9.10646 9.08211 9.05789 9.03379 9.00983 8.98598 8.96227 8.93867 8.91520 8.89185 8.86862 8.84551 8.82252 8.79964 8.77689 8.75425 8.73172 8.70931 8.68701 8.66482 8.64275 8.62078 8.59893 8.57718 8.55555 8.53402 8.51259 8.49128 8.47007 8.44896 8.42795 8.40705 8.38625 8.36555 8.34496 8.32446 8.30406 8.28376 8.26355 8.24345 8.22344 8.20352 8.1837C 8.16398 8.1443c .12278 .12308 .12338 .12367 .12397 .12426 .12456 .12485 .12515 .12544 .12574 .12603 .12633 .12662 .12692 .12722 .12751 .12781 .12810 .12840 .12869 .12899 .12929 .12958 .12988 .13017 .13047 .13076 .13106 .13136 .13165 .13195 .13224 .13254 .13284 .13313 .13343 .13372 .13402 .13432 .13461 .13491 .13521 .13550 .13580 .13609 .13639 .13669 .13698 .13728 .13758 .13787 .13817 .13846 i .13876 i .13906 : .13935 ! .13965 1 .13995 ! .14024 i .ll054 8.14435 8.12481 8.10536 8.08600 8.06674 8.04756 8.02848 8.00948 7.99058 7.97176 7.95302 7.93438 7.91582 7.89734 7.87895 7.86064 7.84242 7.82428 7.80622 7.78825 7.77035 7.75254 7.73480 7.71715 7.69957 7.68208 7.66466 7.64732 7.63005 7.61287 7.59575 7.57872 7.56176 7.54487 7.52806 7.51132 7.49465 7.47806 7.46154 7.44509 7.42871 7.41240 7.39616 7.37999 7.36389 7.34786 7.33190 7.31600 7.30018 7.28442 7.26873 7.25310 7.23754 7.22204 7.20661 7.19125 7.17594 7.16071 7.14553 7.13042 7.11537 .14054 .14084 .14113 .14143 .14173 .14202 .14232 .14262 .14291 .14321 .14351 .14381 .14410 .14440 .14470 .14499 .14529 .14559 .14588 .14618 .14648 .14678 .14707 .14737 .14767 .14796 .14826 .14856 .14886 .14915 .14945 .14975 .15005 .15034 .15064 .15094 .15124 .15153 .15183 .15213 .15243 .15272 .15302 .15332 .15362 .15391 .15421 .15451 .15481 .15511 .15540 .15570 .15600 .15630 .15660 .15689 .15719 .15749 .15779 .15809 .15838 7.11537 7.10038 7.08546 7.07059 7.05579 7.04105 7.02637 7.01174 6.99718 6.98268 6.96823 6.95385 6.93952 6.92525 6.91104 6.89688 6.88278 6.86874 6.85475 6.84082 6.82694 6.81812 6.79936 6.78564 6.77199 6.75838 6.74483 6.73133 6.71789 6.70450 6.69116 6.67787 6.66463 6.65144 6.63831 6.62523 6.61219 6.59921 6.58627 6.57339 6.56055 6.54777 6.53503 6.52234 6.50970 6.49710 6.48456 6.47206 6.45961 6.44720 6.43484 6.42253 6.41026 6.39804 6.38587 6.37374 6.36165 6.34961 6.33761 6.32566 6.31375 .15838 .15868 .15898 .15928 .15958 .15988 .16017 .16047 .16077 .16107 .16137 .16167 .16196 .16226 .16256 .16286 .16316 .16346 .16376 .16405 .16435 .16465 .16495 .16525 .16555 .16585 .16615 .16645 .16674 .16704 .16734 .16764 .16794 .16824 .16854 .16884 .16914 .16944 .16974 .17004 .17033 .17063 .17093 .17123 .17153 .17183 .17213 .17243 .17273 .17303 .17333 .17363 .17393 .17423 .17453 .17483 .17513 .17543 .17573 .17603 .17633 6.31375 6.30189 6.29007 6.27829 6.26655 6.25486 6.24321 6.23160 6.22003 6.20851 6.19703 6.18559 6.17419 6.16283 6.15151 6.14023 6.12899 6.11779 6.10664 6.09552 6.08444 6.07340 6.06240 6.05143 6.04051 6.02962 6.01878 6.00797 5.99720 5.98646 5.97576 5.96510 5.95448 5.94390 5.93335 5.92283 5.91236 5.90191 5.89151 5.88114 5.87080 5.86051 5.85024 5.84001 5.82982 5.81966 5.80953 5.79944 5.78938 5.77936 5.76937 5.75941 5.74949 5.73960 5.72974 5.71992 5.71013 5.70037 5.69064 5.68094 5.67128 60 59 58 57 56 55 54 53 52 51 50 49 48 47 46 45 44 43 42 41 40 39 38 37 36 35 34 33 32 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 Cotang ; Tang Cotang ; Tang Cotang ; Tang Cotang ; Tang Cotang ' Tang 84 ° 83 ° 82 ° 81 ° 80 ° 486 NATURAL TANGENTS AND COTANGENTS. 10° 11° 12° 18 ° 14 ° f Tang Cotang Tang Cotang Tang Cotang Tang Cotang Tang Cotang 0 .17633 5.67128 .19438 5.14455 .21256 4.70463 .23087 4.33148 .24933 4.01078 60 1 .17663 5.66165 .19468 5.13658 .21286 4.69791 .23117 4.32573 .24964 4.00582 59 2 .17693 5.65205 .19498 5.12862 .21316 4.69121 .23148 4.32001 .24995 4.00086 58 3 .17723 5.64248 .19529 5.12069 .21347 4.68452 .23179 4.31430 .25026 3.99592 57 4 .17753 5.63295 .19559 5.11279 .21377 4.67786 .23209 4.30860 .25056 3.99099 56 5 .17783 5.62344 .19589 5.10490 .21408 4.67121 .23240 4.30291 .25087 3.98607 55 6 .17813 5.61397 .19619 5.09704 .21438 4.66458 .23271 4.29724 .25118 3.98117 54 7 .17843 5.60452 .19649 5.08921 .21469 4.65797 .23301 4.29159 .25149 3.97627 53 8 .17873 5.59511 .19680 5.08139 .21499 4.65138 .23332 4.28595 .25180 3.97139 52 9 .17903 5.58573 .19710 5.07360 .21529 4.64480 .23363 4.28032 .25211 3.96651 51 10 .17933 5.57638 .19740 5.06584 .21560 4.63825 .23393 4.27471 .25242 3.96165 50 11 .17963 5.56706 .19770 5.05809 .21590 4.63171 .23424 4.26911 .25273 3.95680 49 12 .17993 5.55777 .19801 5.05037 .21621 4.62518 .23455 4.26352 .25304 3.95196 48 13 .18023 5.54851 .19831 5.04267 .21651 4.61868 .23485 4.25795 .25335 3.94713 47 14 .18053 5.53927 .19861 5.03499 .21682 4.61219 .23516 4.25239 .25366 3.94232 46 .18083 5.53007 .19891 5.02734 .21712 4.60572 .23547 4.24685 .25397 3.93751 45 16 .18113 5.52090 .19921 5.01971 .21743 4.59927 .23578 4.24132 .25428 3.93271 44 17 .18143 5.51176 .19952 5.01210 .21773 4.59283 .23608 4.23580 .25459 3.92793 43 18 .18173 5.50264 .19982 5.00451 .21804 4.58641 .23639 4.23030 .25490 3.92316 42 19 .18203 5.49356 .20012 4.99695 .21834 4.58001 .23670 4.22481 .25521 3.91839 41 20 .18233 5.48451 .20042 4.98940 .21864 4.57363 .23700 4.21933 .25552 3.91364 40 21 .18263 5.47548 .20073 4.98188 .21895 4.56726 .23731 4.21387 .25583 3.90890 39 22 .18293 5.46648 .20103 4.97438 .21925 4.56091 .23762 4.20842 .25614 3.90417 38 23 .18323 5.45751 .20133 4.96690 .21956 4.55458 .23793 4.20298 .25645 3.89945 37 24 .18353 5.44857 .20164 4.95945 .21986 4.54826 .23823 4.19756 .25676 3.89474 36 25 .18384 5.43966 .20194 4.95201 .22017 4.54196 .23854 4.19215 .25707 3.89004 35 26 .18414 5.43077 .20224 4.94460 .22047 4.53568 .23885 4.18675 .25738 3.88536 34 27 .18444 5.42192 .20254 4.93721 .22078 4.52941 .23916 4.18137 .25769 3.88068 33 28 .18474 5.41309 .20285 4.92984 .22108 4.52316 .23946 4.17600 .25800 3.87601 32 29 .18504 5.40429 .20315 4.92249 .22139 4.51693 .23977 4.17064 .25831 3.87136 31 30 .18534 5.39552 .20345 4.91516 .22169 4.51071 .24008 4.16530 .25862 3.86671 30 31 .18564 5.38677 .20376 4.90785 .22200 4.50451 .24039 4.15997 .25893 3.86208 29 32 .18594 5.37805 .20406 4.90056 .22231 4.49832 .24069 4.15465 .25924 3.85745 28 33 .18624 5.36936 .20436 4.89330 .22261 4.49215 .24100 4.1'4934 .25955 3.85284 27 34 .18654 5.36070 .20466 4.88605 .22292 4.48600 .24131 4.14405 .25986 3.84824 26 35 .18684 5.35206 .20497 4.87882 .22322 4.47986 .24162 4.13877 .26017 3.84364 25 36 .18714 5.34345 .20527 4.87162 .22353 4.47374 .24193 4.13350 .26048 3.83906 24 87 .18745 5.33487 .20557 4.86444 .22383 4.46764 .24223 4.12825 .26079 3.83449 23 38 .18775 5.32631 .20588 4.85727 .22414 4.46155 .24254 4.12301 .26110 3.82992 22 39 .18805 5.31778 .20618 4.85013 .22444 4.45548 .24285 4.11778 .26141 3.82537 21 40 .18835 5.30928 .20648 4.84300 .22475 4.44942 .24316 4.11256 .26172 3.82083 20 41 .18865 5.30080 .20679 4.83590 .22505 4.44338 .24347 4.10736 .26203 3.81630 19 42 .18895 5.29235 .20709 4.82882 .22536 4.43735 .24377 4.10216 .26235 3.81177 18 43 .18925 5.28393 .20739 4.82175 .22567 4.43134 .24408 4.09699 .26266 3.80726 17 44 .18955 5.27553 .20770 4.81471 .22597 4.42534 .24439 4.09182 .26297 3.80276 16 45 .18986 5.26715 .20800 4.80769 .22628 4.41936 .24470 4.08666 .26328 3.79827 15 46 .19016 5.25880 .20830 4.80068 .22658 4.41340 .24501 4.08152 .26359 3.79378 14 47 .19046 5.25048 .20861 4.79370 .22689 4.40745 .24532 4.07639 .26390 3.78931 13 48 .19076 5.24218 .20891 4.78673 .22719 4.40152 .24562 4.07127 .26421 3.78485 12 49 .19106 5.23391 .20921 4.77978 .22750 4.39560 .24593 4 06616 .26452 3.78040 11 50 .19136 5.22566 .20952 4.77286 .22781 4.38969 .24624 4.06107 .26483 3.77595 10 51 .19166 5.21744 .20982 4.76595 .22811 4.38381 .24655 4.05599 .26515 3.77152 9 52 .19197 5.20925 .21013 4.75906 .22842 4.37793 .24686 4.05092 .26546 3.76709 8 53 .19227 5.20107 .21043 4.75219 .22872 4.37207 .24717 4.04586 .26577 3.76268 7 54 .19257 5.19293 .21073 4.74534 .22903 4.36623 .24747 4.04081 .26608 3.75828 6 55 .19287 5.18480 .21104 4.73851 .22934 4.36040 .24778 4.03578 .26639 3.75388 5 56 .19317 5.17671 .21134 4.73170 .22964 4.35459 .24809 4.03076 .26670 3.74950 4 57 .19347 5.16863 .21164 4.72490 .22995 4.34879 .24840 4.02574 .26701 3,74512 3 58 .19378 5.16058 .21195 4.71813 .23026 4.34300 .24871 4.02074 .26733 3.74075 2 59 .19408 5.15256 .21225 4.71137 .23056 4.3J5723 .24902 4.01576 .26764 3.73640 1 60 .19438 5.14455 .21256 4.70463 .23087 4.33148 .24933 4.01078 .26795 3.73205 0 Cotang Tang Cotang Tang Cotang Tang Cotang Tang Cotang Tang f 79 ° 78 ° 77 ° 76 ° 75 ° NATURAL TANGENTS AND COTANGENTS. 467 15° 16° 17° 18° 19° / - Tang Cotang Tang Cotang Tang Cotang Tang Cotang Tang Cotang o .26795 3.73205 .28675 3.48741 .30573 3.27085 .32492 3.07768 .34433 2.90421 60 26826 3.72771 .28706 3.48359 .30605 3.26745 .32524 3.07464 .34465 2.90147 59 26857 3.72338 .28738 3.47977 .30637 3.26406 .32556 3.07160 .34498 2.89873 58 3 .26888 3.71907 .28769 3.47596 .30669 3.26067 .32588 3.06857 .34530 2.89600 57 26920 3.71476 .28800 3.47216 .30700 3.25729 .32621 3.06554 .34563 2.89327 56 .26951 3.71046 .28832 3.46837 .30732 3.25392 .32653 3.06252 .34596 2.89055 55 .26982 3.70616 .28864 3.46458 .30764 3.25055 .32685 3.05950 .34628 2.88783 54 7 .27013 3.70188 .28895 3.46080 .30796 3.24719 .32717 3.05649 .34661 2.88511 53 .27044 3.69761 .28927 3.45703 .30828 3.24383 .32749 3.05349 .34693 2.88240 52 9 .27076 3.69335 .28958 3.45327 .30860 3.24049 .32782 3.05049 .34726 2.87970 51 10 .27107 3.68909 .28990 3.44951 .30891 3.23714 .32814 3.04749 .34758 2.87700 50 27138 3.68485 .29021 3.44576 .30923 3.23381 .32846 3.04450 .34791 2.87430 49 12 .27169 3.68061 .29053 3.44202 .30955 3.23048 .32878 3.04152 .34824 2.87161 48 13 .27201 3.67638 .29084 3.43829 .30987 3.22715 .32911 3.03854 .34856 2.86892 47 14 .27232 3.67217 .29116 3.43456 .31019 3.22384 .32943 3.03556 .34889 2.86624 46 15 27263 3.66796 .29147 3.43084 .31051 3.22053 .32975 3.03260 .34922 2 .86356 45 16 27294 3.66376 .29179 3.42713 .31083 3.21722 .33007 3.02963 .34954 2.86089 44 17 27326 3.65957 .29210 3.42343 .31115 3.21392 .33040 3.02667 .34987 2.85822 43 18 .27357 3.65538 .29242 3.41973 .31147 3.21063 .33072 3.02372 .35020 2.85555 42 19 .27388 3.65121 .29274 3.41604 .31178 3.20734 .33104 3.02077 .35052 2.85289 41 20 .27419 3.64705 .29305 3.41236 .31210 3.20406 .33136 3.01783 .35085 2.85023 40 21 27451 3.64289 .29337 3.40869 .31242 3.20079 .33169 3.01489 .35118 2.84758 39 27482 3.63874 .29368 3.40502 .31274 3.19752 .33201 3.01196 .35150 2.84494 38 23 27513 3.63461 .29400 3.40136 .31306 3.19426 .33233 3.00903 .35183 2.84229 37 27545 3.63048 .29432 3.39771 .31338 3.19100 .33266 3.00611 .35216 2.83965 36 25 27576 3.62636 .29463 3.39406 .31370 3.18775 .33298 3.00319 .35248 2.83702 35 27607 3.62224 .29495 3.39042 .31402 3 18451 .33330 3.00028 .35281 2.83439 34 27638 3.61814 .29526 3.38679 .31434 3.18127 .33363 2.99738 .35314 2.83176 33 28 .27670 3.61405 .29558 3.38317 .31466 3.17804 .33395 2.99447 .35346 2.82914 32 29 .27701 3.60996 .29590 3.37955 .31498 3.17481 .33427 2.99158 .35379 2.82653 31 30 .27732 3.60588 .29621 3.37594 .31530 3.17159 .33460 2.98868 .35412 2.82391 30 31 .27764 3.60181 .29653 3.37234 .31562 3.16838 .33492 2.98580 .35445 2.82130 29 32 .27795 3.59775 .29685 3.36875 .31594 3.16517 .33524 2.98292 .35477 2.81870 28 33 '.27826 3.59370 .29716 3.36516 .31626 3.16197 .33557 2.98004 .35510 2.81610 27 34 .27858 3.58966 .29748 3.36158 .31658 3.15877 .33589 2.97717 .35543* 2.81350 26 35 .27889 3.58562 .29780 3.35800 .31690 3.15558 .33621 2.97430 .35576 2.81091 25 36 .27921 3.58160 .29811 3.35443 .31722 3.15240 .33654 2.97144 .35608 2.80833 24 37 .27952 3.57758 .29843 3.35087 .31754 3.14922 .33686 2.96858 .35641 2.80574 23 38 .27983 3.57357 .29875 3.34732 .31786 3.14605 .33718 2.96573 <35674 2.80316 22 39 .28015 3.56957 .29906 3.34377 .31818 3.14288 .33751 2.96288 .35707 2.80059 21 40 !28046 3.56557 .29938 3.34023 .31850 3.13972 .33783 2.96004 .35740 2.79802 20 41 .28077 3.56159 .29970 3.33670 .31882 3.13656 .33816 2.95721 .35772 2.79545 19 42 .28109 3.55761 .30001 3.33317 .31914 3.13341 .33848 2.95437 .35805 2.79289 18 43 .28140 3.55364 .30033 3.32965 .31946 3.13027 .33881 2.95155 .35838 2.79033 17 44 .28172 3.54968 .30065 3.32614 .31978 3.12713 .33913 2.94872 .35871 2.78778 16 45 .28203 3.54573 .30097 3.32264 .32010 3.12400 .33945 2.94591 .35904 2 .78523 15 46 .28234 3.54179 .30128 3.31914 .32042 3.12087 .33978 2.94309 .35937 2.78269 14 47 .28266 3.53785 .30160 3.31565 .32074 3.11775 .34010 2.94028 .35969 2.78014 13 48 .28297 3.53393 .30192 3.31216 .32106 3.11464 .34043 2.93748 .36002 2.77761 12 49 .28329 3.53001 .30224 3.30868 .32139 3.11153 .34075 2.93468 .36035 2 .77507 11 50 .28360 3.52609 .30255 3.30521 .32171 3.10842 .34108 2.93189 .36068 2.77254 10 51 .28391 3.52219 .30287 3.30174 .32203 3.10532 .34140 2.92910 .36101 2.77002 9 52 .28423 3.51829 .30319 3.29829 .32235 3.10223 .34173 2.92632 .36134 2.76750 8 53 .28454 3.51441 .30351 3.29483 .32267 3.09914 .34205 2.92354 .36167 2.76498 7 54 .28486 3.51053 .30382 3.29139 .32299 3.09606 .34238 2.92076 .36199 2.76247 6 55 .28517 3.50666 .30414 3.28795 .32331 3.09298 .34270 2.91799 .36232 2.75996 5 56 .28549 3.50279 .30446 3.28452 .32363 3.08991 .34303 2.91523 .36265 2.75746 4 57 .28580 3.49894 .30478 3.28109 .32396 3.08685 .34335 2.91246 .36298 2.75496 3 58 .28612 3.49509 .30509 3.27767 .32428 3.08379 .34368 2.90971 .36331 2.75246 2 59 ’*28643 3.49125 .30541 3.27426 .32460 3.08073 .34400 2.90696 .36364 2.74997 1 60 .28675 3.48741 .30573 3.27085 .32492 3.07768 .34433 2.90421 .36397 2.74748 0 Cotang ; Tang Cotang ; Tang Cotang Tang Cotang Tang Cotang j Tang f t 74° 73° 72° 71° 70° 468 NATURAL TANGENTS AND COTANGENTS. 20° 21° 22° 23° 24° / Tang Cotang Tang Cotang Tang Cotang Tang Cotang Tang Cotang 0 .36397 2.74748 .38386 2.60509 .40403 2.47509 .42447 2.35585 .44523 2.24604 60 1 .36430 2.74499 .38420 2.60283 .40436 2.47302 .42482 2.35395 .44558 2.24428 59 2 .36463 2.74251 .38453 2.60057 .40470 2.47095 .42516 2.35205 .44593 2.24252 58 3 .36496 2.74004 .38487 2.59831 .40504 2.46888 .42551 2.35015 .44627 2.24077 57 4 .36529 2.73756 .38520 2.59606 .40538 2.46682 .42585 2.34825 .44662 2.23902 56 5 .36562 2.73509 .38553 2.59381 .40572 2.46476 .42619 2.34636 .44697 2.23727 55 6 .36595 2.73263 .38587 2.59156 .40606 2.46270 .42654 2.34447 .44732 2.23553 54 7 .36628 2.73017 .38620 2.58932 .40640 2.46065 .42688 2.34258 .44767 2.23378 53 8 .36661 2.72771 .38654 2.58708 .40674 2.45860 .42722 2.34069 .44802 2.23204 52 9 .36694 2.72526 .38687 2.58484 .40707 2.45655 .42757 2.33881 .44837 2.23030 51 10 .36727 2.72281 .38721 2.58261 .40741 2.45451 .42791 2.33693 .44872 2.22857 50 11 .36760 2.72036 .38754 2.58038 .40775 2.45246 .42826 2.33505 .44907 2.22683 49 12 .36793 2.71792 .38787 2.57815 .40809 2.45043 .42860 2.33317 .44942 2.22510 48 13 .36826 2.71548 .38821 2.57593 .40843 2.44839 .42894 2.33130 .44977 2.22337 47 14 .36859 2.71305 .38854 2.57371 .40877 2.44636 .42929 2.32943 .45012 2.22164 46 15 .36892 2.71062 .38888 2.57150 .40911 2.44433 .42963 2.32756 .45047 2.21992 45 16 .36925 2.70819 .38921 2.56928 .40945 2.44230 .42998 2.32570 .45082 2.21819 44 17 .36958 2.70577 .38955 2.56707 .40979 2.44027 .43032 2.32383 .45117 2.21647 43 18 .36991 2.70335 .38988 2.56487 .41013 2.43825 .43067 2.32197 .45152 2.21475 42 19 .37024 2.70094 .39022 2.56266 .41047 2.43623 .43101 2.32012 .45187 2.21304 41 20 .37057 2.69853 .39055 2.56046 .41081 2.43422 .43136 2.31826 .45222 2.21132 40 21 .37090 2.69612 .39089 2.55827 .41115 2.43220 .43170 2.31641 .45257 2.20961 39 22 .37123 2.69371 .39122 2.55608 .41149 2.43019 43205 2.31456 .45292 2.20790 38 23 .37157 2.69131 .39156 2.55389 .41183 2.42819 .43230 2.31271 .45327 2.20619 37 24 .37190 2.68892 .39190 2.55170 .41217 2.42618 .43274 2.31086 .45362 2.20449 36 25 .37223 2.68653 .39223 2.54952 .41251 2 42418 .43308 2.30902 .45397 2.20278 35 26 .37256 2.68414 .39257 2.54734 .41285 2.42218 .43343 2.30718 .45432 2.20108 34 27 .37289 2.68175 .39290 2.54516 .41319 2.42019 .43378 2.30534 .45467 2.19938 33 28 .37322 2.67937 .39324 2.54299 .41353 2.41819 .43412 2.30351 .45502 2.19769 32 29 .37355 2.67700 .39357 2.54082 .41387 2.41620 .43447 2.30167 .45538 2.19599 31 30 .37388 2.67462 .39391 2.53865 .41421 2.41421 .43481 2.29984 .45573 2.19430 30 31 .37422 2.67225 .39425 2.53648 .41455 2.41223 .43516 2.29801 .45608 2.19261 29 32 .37455 2.66989 .39458 2.53432 .41490 2.41025 .43550 2.29619 .45643 2.19092 28 33 .37488 2.66752 .39492 2.53217 .41524 2.40827 .43585 2.29437 .45678 2.18923 27 34 .37521 •2.66516 .39526 2.53001 .41558 2.40629 .43620 2.29254 .45713 2.18755 26 35 .37554 2.66281 .39559 2.52786 .41592 2.40432 .43654 2.29073 .45748 2.18587 25 36 .37588 2.66046 .39593 2.52571 .41626 2.40235 .43689 2.28891 .45784 2.18419 24 37 .37621 2.65811 .39626 2.52357 .41660 2.40038 .43724 2.28710 .45819 2.18251 23 38 .37654 2.65576 .39660 2.52142 .41694 2.39841 .43758 2.28528 .45854 2.18084 22 39 .37687 2.65342 .39694 2.51929 .41728 2.39645 .43793 2.28348 .45889 2.17916 21 40 .37720 2.65109 .39727 2.51715 .41763 2.39449 .43828 2.28167 .45924 2.17749 20 41 .37754 2.64875 .39761 2.51502 .41797 2.39253 .43862 2.27987 .45960 2.17582 19 42 .37787 2.64642 .39795 2.51289 .41831 2.39058 .43897 2.27806 .45995 2.17416 18 43 .37820 2.64410 .39829 2.51076 .41865 2.38863 .43932 2.27626 .46030 2.17249 17 44 .37853 2.64177 .39862 2.50864 .41899 2.38668 .43966 2.27447 .46065 2.17083 16 45 .37887 2.63945 .39896 2.50652 .41933 2.38473 .44001 2.27267 .46101 2.16917 15 46 .37920 2.63714 .39930 2.50440 .41968 2.38279 .44036 2.27088 .46136 2.16751 14 47 .37953 2.63483 .39963 2.50229 .42002 2.38084 .44071 2.26909 .46171 2.16585 13 48 .37986 2.63252 .39997 2.50018 .42036 2.37891 .44105 2.26730 .46206 2.16420 12 49 .38020 2.63021 .40031 2.49807 .42070 2.37697 .44140 2.26552 .46242 2.16255 11 50 .38053 2.62791 .40065 2.49597 .42105 2.37504 .44175 2.26374 .46277 2.16090 10 51 .38086 2.62561 .40098 2.49386 .42139 2.37311 .44210 2.26196 .46312 2.15925 9 52 .38120 2.62332 .40132 2.49177 .42173 2.37118 .44.244 2.26018 .46348 2.15760 8 53 .38153 2.62103 .40166 2.48967 .42207 2.36925 .44279 2.25840 .46383 2.15596. 7 54 .38186 2.61874 .40200 2.48758 .42242 2.36733 .44314 2.25663 .46418 2.15432 6 55 .38220 2.61646 .40234 2.48549 .42276 2.36541 .44349 2.25486 .46454 2.15268 5 56 .38253 2.61418 .40267 2.48340 .42310 2.36349 .44384 2.25309 .46489 2.15104 4 57 .38286 2.61190 .40301 2.48132 .42345 2.36158 .44418 2.25132 .46525 2.14940 3 58 .38320 2.60963 .40335 2.47924 .42379 2.35967 .44453 2.24956 .46560 2.14777 2 59 .38353 2.60736 .40369 2.47716 .42413 2.35776 .44488 2.24780 .46595 2.14614 1 60 .38386 2.60509 .40403 2.47509 .42447 2.35585 .44523 2.24604 .46631 2.14451 0 Cotang Tang Cotang Tang Cotang Tang Cotaug Tang Cotang Tang f 69° 68° 67° 66° 65° NATURAL TANGENTS AND COTANGENTS. 469 25° 26° 27° 28° 29° t t Tang Cotang Tang Cotang Tang Cotang Tang Cotang Tang Cotang o 46631 2.14451 .48773 2.05030 .50953 1.96261 .53171 1.88073 .55431 1.80405 60 \ 46666 2.14288 .48809 2.04879 .50989 1.96120 .53208 1.87941 .55469 1.80281 59 46702 2.14125 .48845 2.04728 .51026 1.95979 .53246 1.87809 .55507 1.80158 58 3 46737 2.13963 .48881 2.04577 .51063 1.95838 .53283 1.87677 .55545 1.80034 57 4 46772 2.13801 .48917 2.04426 .51099 1.95698 .53320 1.87546 .55583 1.79911 56 46»n« 2 13639 .48953 2.04276 .51136 1.95557 .53358 1.87415 .55621 1.79788 55 46R43 2 13477 .48989 2.04125 .51173 1.95417 .53395 1.87283 .55659 1.79665 54 40R79 2 13316 .49026 2.03975 .51209 1.95277 .53432 1.87152 .55697 1.79542 53 46914 2 13154 .49062 2.03825 .51246 1.95137 .53470 1.87021 .55736 1.79419 52 g 46950 2.12993 .49098 2.03675 .51283 1.94997 .53507 1.86891 .55774 1.79296 51 10 .46985 2.12832 .49134 2.03526 .51319 1.94858 .53545 1.86760 .55812 1.79174 50 U 47021 2.12671 .49170 2.03376 .51356 1.94718 .53582 1.86630 .55850 1.79051 49 12 47056 2.12511 .49206 2.03227 .51393 1.94579 .53620 1.86499 .55888 1.78929 48 13 47092 2.12350 .49242 2.03078 .51430 1.94440 .53657 1.86369 .55926 1.78807 47 14 47128 2.12190 .49278 2.02929 .51467 1.94301 .53694 1.86239 .55964 1.78685 46 15 47163 2.12030 .49315 2.02780 .51503 1.94162 .53732 1.86109 .56003 1.78563 45 16 47199 2.11871 .49351 2.02631 .51540 1.94023 .53769 1.85979 .56041 1.78441 44 17 47234 2.11711 .49387 2.02483 .51577 1.93885 .53807 1.85850 .56079 1.78319 43 18 47270 2.11552 .49423 2.02335 .51614 1.93746 .53844 1.85720 .56117 1.78198 42 19 47305 2.11392 .49459 2.02187 .51651 1.93608 .53882 1.85591 .56156 1.78077 41 20 .47341 2.11233 .49495 2.02039 .51688 1.93470 .53920 1.85462 .56194 1.77955 40 21 47377 2 11075 .49532 2.01891 .51724 1.93332 .53957 1.85333 .56232 1.77834 39 22 .47412 2.10916 .49568 2.01743 .51761 1.93195 .53995 1.85204. .56270 1.77713 38 23 .47448 2.10758 .49604 2.01596 .51798 1.93057 .54032 1.85075 .56309 1.77592 37 24 .47483 2.10600 .49640 2.01449 .51835 1.92920 .54070 1.84946 .56347 1.77471 36 25 47519 2.10442 .49677 2.01302 .51872 1.92782 .54107 1.84818 .56385 1.77351 35 26 2.10284 .49713 2.01155 .51909 1.92645 .54145 1.84689 .56424 1.77230 34 27 47590 2.10126 .49749 2.01008 .51946 1.92508 .54183 1.84561 .56462 1.77110 33 28 .47626 2.09969 .49786 2.00862 .51983 1.92371 .54220 1.84433 .56501 1.76990 32 29 .47662 2.09811 .49822 2.00715 .52020 1.92235 .54258 1.84305 .56539 1.76869 31 30 .47698 2.09654 .49858 2.00569 .52057 1.92098 .54296 1.84177 .56577 1.76749 30 31 .47733 2.09498 .49894 2.00423 .52094 1.91962 .54333 1.84049 .56616 1.76629 29 32 .47769 2.09341 .49931 2.00277 .52131 1.91826 .54371 1.83922 .56654 1.76510 28 33 .47805 2.09184 .49967 2.00131 .52168 1.91690 .54409 1.83794 .56693 1.76390 27 34 .47840 2.09028 .50004 1.99986 .52205 1.91554 .54446 1.83667 .56731 1.76271 26 35 .47876 2.08872 .50040 1.99841 .52242 1.91418 .54484 1.83540 .56769 1.76151 25 36 .47912 2.08716 .50076 1.99695 .52279 1.91282 .54522 1.83413 .56808 1.76032 24 37 .47948 2.08560 .50113 1.99550 .52316 1.91147 .54560 1.83286 .56846 1.75913 23 38 .47984 2.08405 .50149 1.99406 .52353 1.91012 .54597 1.83159 .56885 1.75794 22 39 • .48019 2.08250' .50185 1.99261 .52390 1.90876 .54635 1.83033 .56923 1.75675 21 40 .48055 2.08094 .50222 1.99116 .52427 1.90741 .54673 1.82906 .56962 1.75556 20 41 .48091 2.07939 .50258 1.98972 .52464 1.90607 .54711 1.82780 .57000 1.75437 19 42 .48127 2.07785 .50295 1.98828 .52501 1.90472 .54748 1.82654 .57039 1.75319 18 43 .48163 2.07630 .50331 1.98684 .52538 1.90337 .54786 1.82528 .57078 1.75200 17 44 .48198 2.07476 .50368 1.98540 .52575 1.90203 .54824 1.82402 .57116 1.75082 16 *5 .48234 2.07321 .50404 1.98396 .52613 1.90069 .54862 1.82276 .57155 1.74964 15 46 .48270 2.07167 .50441 1.98253 .52650 1.89935 .54900 1.82150 .57193 1.74846 14 47 .48306 2.07014 .50477 1.98110 .52687 1.89801 .54938 1.82025 .57232 1.74728 13 48 .48342 2.06860 .50514 1.97966 .52724 1.89667 .54975 1.81899 .57271 1.74610 12 49 .48378 2.06706 .50550 1.97823 .52761 1.89533 .55013 1.81774 .57309 1.74492 11 50 .48414 2.06553 .50587 1.97681 .52798 1.89400 .55051 1.81649 .57348 1.74375 10 51 .48450 2.06400 .50623 1.97538 .52836 1.89266 .55089 1.81524 .57386 1.74257 9 52 .48486 2 06247 .50660 1.97395 .52873 1.89133 .55127 1.81399 .57425 1.74140 8 53 .48521 2.06094 .50696 1.97253 .52910 1.89000 .55165 1.81274 .57464 1.74022 7 54 .48557 2.05942 .50733 1.97111 .52947 1.88867 .55203 1.81150 .57503 1.73905 6 55 .48593 2.05790 .50769 1.96969 .52985 1.88734 .55241 1.81025 .57541 1.73788 5 56 .48629 2.05637 .50806 1.96827 .53022 1.88602 .55279 1.80901 .57580 1.73671 4 57 .48665 2.05485 .50843 1.96685 .53059 1.88469 .55317 1.80777 .57619 1.73555 3 58 .48701 2.05333 .50879 1.96544 .53096 1.88337 .55355 1.80653 .57657 1.73438 2 59 .48737 2.05182 .50916 1.96402 .53134 1.88205 .55393 1.80529 .57696 1.73321 1 60 .48773 2.05030 .50953 1.96261 .53171 1,88073 .55431 1.80405 .57735 1.73205 0 Cotang Tang Cotang Tang Cotang Tang Cotang Tang Cotang ; Tang t 64° I 63° 62° 61° 60° 470 NATURAL TAX GENTS AND COTANGENTS. 30° 31° 32° 33° 2A° t Tang Cotang Tang Cotang Tang Cotang Tang Cotang Tang Cotang 0 1.73205 .60086 1.66428 .62487 1.60033 .64941 1.53986 .67451 ; 1.48256 ' 60 1 ! .57774 1.73089 .60126 1.66318 .62527 1.59930 .64982 1.53888 .67493 j 1.48163 59 2 .57813 ( 1.72973 .60165 1.66209 .62568 1.59826 .65024 1 1.53791 .67536 j 1.48070 ! 58 3 1 .57851 1.72857 .60205 1.66099 .62608 1.59723 .65065 i 1.53693 .67578 1.47977 j 57 4 | .57890 1.72741 .60245 1.65990 .62649 1.59620 .65106 1.53595 .67620 i 1.47885 ; 56 .57929 1.72625 .60284 1.65881 .62689 1.59517 .65148 1.53497 .67663 1 1.47792 ! 55 6 .57968 1.72509 .60324 1.65772 .62730 1.59414 .65189 ! 1.53400 .67705 1.47699 : 54 1.72393 .60364 1.65663 .62770 : 1.59311 .65231 1.53302 .67748 I 1.47607 i 53 8 1 .55046 1 1.72278 .60403 1.65554 .62811 1.59208 .65272 1.53205 .67790 j 1.47514 | 52 9 .58085 1.72163 .60443 1.65445 .62852 1.59105 .65314 1.53107 .67832 | 1.47422 51 10 1 .58124 i 1.72047 .60483 1.65337 .62892 1.59002 .65355 i 1.53010 .67875 I 1.47330 ! 50 11 ; .58162 ' 1.71932 .60522 1.65228 .62933 1.5S900 .65397 | 1.52913 .67917 1.47238 49 12 .58201 1.71817 .60562 1.65120 .62973 | 1.58797 .65438 i 1.52816 .67960 1.47146 ! 48 13 1 .58240 1.71702 .60602 1.65011 .63014 I 1.58695 .65480 1.52719 .68002 1.47053 | 47 14 | .58279 1.71588 .60642 1.64903 .63055 1.58593 .65521 1 1.52622 .68045 1.46962 46 .58318 1.71473 .60681 1.64795 .63095 1.58490 .65563 ! 1.52525 .68088 ! 1.46870 45 16 j .58357 1.71358 .60721 1.64687 .63136 1.58388 .65604 1.52429 .68130 1 1.4677S i 44 IT 1 .58396 1.71244 .60761 1.64579 .63177 1.5S286 .65646 1.52332 .68173 i 1.46686 43 18 j .58435 1.71129 .60801 1.64471 .63217 1.58184 .65688 j 1.52235 .68215 1.46595 | 42 19 .58474 1.71015 .60841 1.64363 .63258 ! 1.58083 .657*29 ! 1.52139 .68258 1.46503 i 41 20 1 .58513 1.70901 .60881 ! 1.64256 .63299 1.57981 .65771 j 1.52043 .68301 1.46411 40 21 .58552 1.70787 .60921 1.64148 .63340 . 1.57879 .65813 j 1.51946 .68343 1.46320 39 22 .58591 1.70673 .60960 1.64041 .63380 1.57778 .65854 i 1.51850 .68386 1.46229 38 23 j .58631 1.70560 .61000 1.63934 .63421 | 1 .57676 .65896 ! 1.51754 .68429 1.46137 37 24 1 .58670 1.70446 .61040 1.63826 .63462 ! 1.5i575 .65938 1.51658 .68471 ! 1.46046 I 36 25 1 .58709 1.70332 .610S0 1.63719 .63503 1.57474 .65980 1.51562 .68514 | 1.45955 26 .58748 1.70219 .61120 1.63612 .63544 1.57372 .66021 I 1.51466 .68557 1.45864 1 1 34 27 .58787 1.70106 .61160 1.63505 .63584 i 1.57271 .66063 1 1.51370 .68600 1.45773 1 33 28 .58826 1.69992 .61200 1.63398 .63625 1.57170 .66105 1 1.51275 .68642 1.45682 L 32 29 .58865 ! 1.69879 .61240 1.63292 .63666 ! 1.57069 .66147 J 1.51179 .68685 1.45592 31 30 1 .58905 1 1.69766 .61280 1.63185 .63707 1 1.56969 .66189 1.51084 .68728 1 1.45501 i 30 3! .58944 i 1.69653 .61320 1 1.63079 .63748^1.56868 .66230 ! 1.50988 .68771 | 1.45410 : 29 32 .58983 1.69541 .61360 1.62972 .63789 ! jl. 56767 .66272 ! 1.50893 .68814 ! 1.45320 -28 33 1 .59022 1.69428 .61400 1.62866 .63830 j | 1.56667 .66314 1.50797 .68857 j 1.45229 . 27 34 | .59061 1.69316 .61440 1.62760 .63871 i 1.56566 .66356 ! 1.50702 .68900 ! 1.45139 j 26 35 .59101 j 1.69203 .61480 1.62654 .63912 1 1.56466 .66398 : 1.50607 .68942 1 1.45049 25 36 i .59149 ; 1.69091 .61520 1.62548 .63953 | 1.56366 .66440 1.50512 .68985 i 1.44958 24 37 1 .59179 1.68979 .61561 | 1.62442 .63994 1.56265 .66482 1.50417 .69028 j 1.44868 23 38 I ' .59218 1.68S66 .61601 j 1.62336 .64035 1 1.56165 .66524 1.50322 .69071 ; 1.44778- 22 39 | .59253 1.68754 .61641 1.62230 .64076 I 1.56065 .66566 1.50228 .69114 ! 1.44688 i 21 40 | .59297 | 1.68643 .61681 : 1.62125 .64117 J 1.55966 .66608 1.50133 .69157 j 1.44598 20 41 .59336 * 1.68531 .61721 1.62019 .64158 ! 1.55866 .66650 1.50038 .69200 ! 1.4450S J* 42 ! .59376 1.68419 .61761 1.61914 .64199 ! 1.55766 .66692 1.49944 .69243 1 1.44418 18 43 .59415 1.68308 .61801 1.61808 .64240 j 1.55666 .66734 1.49849 .69286 1.44329 17 44 .59454 1.68196 .61842 1.61703 .64281 1.55567 .66776 1.49755 .69329 1.44239 J® 45 .59494 1.68085 .61882 | 1.61598 .64322 1.55467 .66S18 1.49661 .69372 1.44149 J 3 46 j .59533 1.67974 .61922 1.61493 .64363 1.55368 .66860 1.49566 .69416 1.44060 14 47 I .59573 1.67863 .61962 | 1.61388 .64404 1.55269 .66902 1.49472 .69459 ! 1.43970 ! 13 48 .59612 1.67752 .62003 1.61283 .64446 1.55170 .66944 1.49378 .69502 1.43881 49 j .59651 1.67641 .62043 ! 1.61179 .64487 1.55071 .66986 1.49284 .69545 1.43792 1 11 50 ! .59691 1.67530 .62083 ! 1.61074 .64528 1.54972 .67028 1.49190 .69588 L. 43703 i 10 51 .59730 ' 1.67419 .62124 i 1.60970 .64569 1.54873 .67071 ' 1.49097 .69631 1.43614 9 52 i .59770 1 1.67309 .62164 1 1.60865 .64610 1.54774 .67113 I 1.49003 .69675 1.43525 8 53 ! .59809 i 1.67198 .62204 1.60761 .64652 1.54675 .67155 | 1.48909 .69718 1.43436 7 54 j .59849 1.67088 .62245 , 1.60657 .64693 I 1.54576 .67197 ' 1.48816 .69761 j 1.43347 6 55 .59888 1.66978 .62285 ! 1.60553 .64734 1.54478 .67239 , 1.48722 .69804 | 1.43258 5 56 ' .59928 1.66867 .62325 1.60449 .64775 1.54379 .67232 1.48629 .69847 1.43169 4 57 ■ .59967 1.66757 .62366 ! 1 160345 .64817 1.54281 .67324 1 1.48536 .69891 1.43080 3 58 .60007 1.66647 .62406 1.60241 .64858 1.54183 .67366 1 1.48442 .69934 1.42992 2 59 .60046 1.66538 .62446 1.60137 .64899 1.54085 .67409 1.48349 .69977 1.42903 1 60 .60086 1.66428 .62487 i 1.60033 .64941 1.53986 .67451 | 1.48256 .70021 1.42815 0 Cotang Tang Cotang ] Tang Cotang Tang Cotang Tang Cotang Tang r 59 ° 58 ° 57 ° 56 ° 55 ° NATURAL TANGENTS AND COTANGENTS. 471 35° 36° 37° 38° 39° / f - Tang Cotang Tang Cotang Tang < Cotang Tang < Cotang Tang 1 Cotang 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 .70021 .70064 .70107 .70151 .70194 .70238 .70281 .70325 .70368 .70412 .70455 .70499 .70542 .70586 .70629 .70673 .70717 .70760 .70804 .70848 .70891 .70935 .70979 .71023 .71066 .71110 .71154 .71198 .71242 .71285 .71329 .71373 .71417 .71461 .71505 .71549 .71593 .71637 .71681 .71725 .71769 .71813 .71857 .71901 .71946 .71990 .72034 .72078 .72122 .72167 .72211 .72255 .72299 .72344 .72388 .72432 .72477 .72521 .72565 .72610 .72654 1.42815 L. 42726 L. 42638 L. 42550 1.42462 1.42374 1.42286 1.42198 1.42110 1.42022 1.41934 1.41847 1.41759 1.41672 1.41584 1.41497 1.41409 1.41322 1.41235 1.41148 1.41061 1.40974 1.40887 1.40800 1.40714 1.40627 1.40540 1.40454 1.40367 1.40281 1.40195 1.40109 1.40022 1.39936 1.39850 1.39764 1.39679 1.39593 1.39507 1 .39421 1.39336 1.39250 1.39165 1.39079 1.38994 1.38909 1.38824 1.38738 1.38653 1.38568 1.38484 1.38399 1.38314 1.38229 1.38145 1.38060 1.37976 1.37891 1.37807 1.37722 1.37638 .72654 .72699 .72743 .72788 .72832 .72877 .72921 .72966 .73010 .73055 .73100 .73144 .73189 .73234 .73278 .73323 .73368 .73413 .73457 .73502 .73547 .73592 .73637 .73681 .73726 .73771 .73816 .73861 .73906 .73951 .73996 .74041 .74086 .74131 .74176 .74221 .74267 .74312 .74357 .74402 .74447 .74492 .74538 .74583 .74628 .74674 .74719 .74764 .74810 .74855 .74900 .74946 .74991 .75037 .75082 .75128 .75173 .75219 .75264 ! .75310 1 .75355 L. 37638 .37554 1.37470 L. 37386 1.37302 1.37218 1.37134 1.37050 1.36967 1.36883 1.36800 1.36716 1.36633 1.36549 1.36466 1.36383 1.36300 1.36217 1.36134 1.36051 1 35968 1.35885 1.35802 1.35719 1.35637 1.35554 1.35472 1.35389 1.35307 1.35224 1.35142 1.35060 1.34978 1.34896 1.34814 1.34732 1.34650 1.34568 1.34487 1.34405 1.34323 1.34242 1.34160 1.34079 1.33998 1.33916 1.33835 1.33754 1.33673 1.33592 1.33511 1.33430 1.33349 1.33268 1.33187 1.33107 1.33026 1.32946 1.32865 1.32785 1.32704 .75355 ] .75401 : .75447 : .75492 .75538 .75584 .75629 .75675 .75721 .75767 .75812 .75858 .75904 .75950 .75996 .76042 .76088 .76134 .76180 .76226 .76272 .76318 .76364 .76410 .76456 .76502 .76548 .76594 .76640 .76686 .76733 .76779 .76825 .76871 .76918 .76964 .77010 .77057 .77103 .77149 .77196 .77242 .77289 .77335 .77382 .77428 .77475 .77521 .77568 .77615 .77661 .77708 .77754 .77801 .77848 .77895 i .77941 i .77988 i .78035 ; .78082 L .78129 L. 32704 L. 32624 L. 32544 1.32464 1.32384 1.32304 1.32224 1.32144 1.32064 1.31984 1.31904 1.31825 1.31745 1.31666 1.31586 1.31507 1.31427 1.31348 1.31269 1.31190 1.31110 1.31031 1.30952 1.30873 1.30795 1.30716 1.30637 1.30558 1 .30480 1.30401 1.30323 1.30244 1.30166 1.30087 1.30009 1.29931 1.29853 1.29775 1 .29696 1 .29618 1.29541 1.29463 1.29385 1.29307 1.29229 1.29152 1.29074 1.28997 1.28919 1.28842 1.28764 1.28687 1 .28610 1 .28533 1.28456 1.28379 1.28302 1.28225 1.28148 1.28071 1.27994 .78129 ] .78175 ] .78222 : .78269 : .78316 : .78363 .78410 .78457 .78504 .78551 .78598 .78645 .78692 .78739 .78786 .78834 .78881 .78928 .78975 .79022 .79070 .79117 .79164 .79212 .79259 .79306 .79354 .79401 .79449 .79496 .79544 .79591 .79639 .79686 .79734 .79781 .79829 .79877 .79924 .79972 .80020 .80067 .80115 .80163 .80211 .80258 .80306 .80354 .80402 .80450 .80498 .80546 .80594 .80642 .80690 .80738 .80786 i .80834 l .80882 . .80930 r .80978 L. 2 7994 , L. 27917 , L. 27841 1.27764 1.27688 1.27611 1.27535 1.27458 1.27382 1.27306 1.27230 1.27153 1.27077 1.27001 1 .26925 1.26849 1.26774 1.26698 1.26622 1.26546 1.26471 1.26395 1 .26319 1.26244 1 .26169 1 .26093 1 .26018 1 .25943 1.25867 1.25792 1.25717 1.25642 1.25567 1.25492 1.25417 1.25343 1.25268 1.25193 1.25118 1.25044 1.24969 1.24895 1.24820 1.24746 1.24672 1.24597 1.24523 1.24449 1.24375 1.24301 1.24227 1.24153 1 .24079 1.24005 1.23931 1.23858 1.23784 1.23710 1.23637 1.23563 1 .23490 .80978 : .81027 .81075 : .81123 : .81171 .81220 .81268 .81316 .81364 .81413 .81461 .81510 .81558 .81606 .81655 .81703 .81752 .81800 .81849 .81898 .81946 .81995 .82044 .82092 .82141 .82190 .82238 .82287 .82336 .82385 .82434 .82483 .82531 .82580 .82629 .82678 .82727 .82776 .82825 .82874 .82923 .82972 .83022 .83071 .83120 .83169 .83218 .83268 .83317 .83366 .83415 .83465 .83514 .83564 .83613 .83662 .83712 i .83761 .83811 ; .83860 l .83910 L. 23490 1.23416 1.23343 1.23270 1.23196 1.23123 1.23050 1.22977 1.22904 1.22831 1.22758 1.22685 1.22612 1.22539 1.22467 1.22394 1.22321 1.22249 1.22176 1.22104 1.22031 1.21959 1.21886 1.21814 1.21742 1.21670 1.21598 1.21526 1.21454 1.21382 1.21310 1.21238 1.21166 1.21094 1.21023 1.20951 1.20879 1.20808 1.20736 1.20665 1.20593 1.20522 1.20451 1.20379 1.20308 1.20237 1.20166 1.20095 1.20024 1.19953 1.19882 1.19811 1.19740 1.19669 1.19599 1.19528 1.19457 1.19387 1.19316 1.19246 1.19175 60 59 58 57 56 55 54 53 52 51 50 49 48 47 46 45 44 43 42 41 40 39 38 37 36 35 34 33 32 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 1 2 ; l , 0 Cotan j ? Tang Cotan £ 1 Tang Cotang l Tang Cotang ; Tang Cotani g Tang t f 54° 53° i 52° 51° 50° 472 NATURAL TANGENTS AND COTANGENTS. 40° 41° 42° 43° 440 / ' Tang Cotang Tang Cotang Tang Cotang Tang Cotang Tang Cotang 0 .83910 1.19175 .86929 1.15037 .90040 1.11061 .93252 1.07237 .96569 1.03553 60 1 .83960 1.19105 .86980 1.14969 .90093 1.10996 .93306 1.07174 .96625 1.03493 59 2 .84009 1.19035 .87031 1.14902 .90146 1.10931 .93360 1.07112 .96681 1.03433 58 3 .84059 1.18964 .87082 1.14834 .90199 1.10867 .93415 1.07049 .96738 1.03372 57 4 .84108 1.18894 .87133 1.14767 .90251 1.10802 .93469 1.06987 .96794 1.03312 56 5 .84158 1.18824 .87184 1.14699 .90304 1.10737 .93524 1.06925 .96850 1.03252 55 6 .84208 1.18754 .87236 1.14632 .90357 1.10672 .93578 1.06862 .96907 1.03192 54 7 .84258 1.18684 .87287 1.14565 .90410 1.10607 .93633 1.06800 .96963 1.03132 53 8 .84307 1.18614 .87338 1.14498 .90463 1.10543 .93688 1.06738 .97020 1.03072 52 9 .84357 1.18544 .87389 1.14430 .90516 1.10478 .93742 1.06676 .97076 1.03012 51 10 .84407 1.18474 .87441 1.14363 .90569 1.10414 .93797 1.06613 .97133 1.02952 50 n .84457 1.18404 .87492 1.14296 .90621 1.10349 .93852 1.06551 .97189 1.02892 49 12 .84507 1.18334 .87543 1.14229 .90674 1.10285 .93906 1.06489 .97246 1.02832 48 13 .84556 1 .18264 .87595 1.14162 .90727 1.10220 .93961 1.06427 .97302 1.02772 47 14 .84606 1.18194 .87646 1.14095 .90781 1.10156 .94016 1.06365 .97359 1.02713 46 15 .84656 1.18125 .87698 1.14028 .90834 1.10091 .94071 1.06303 .97416 1.02653 45 16 .84706 1.18055 .87749 1.13961 .90887 1.10027 .94125 1.06241 .97472 1.02593 44 17 .84756 1.17986 .87801 1.13894 .90940 1.09963 .94180 1.06179 .07529 1.02533 43 18 .84806 1.17916 .87852 1.13828 .90993 1.09899 .94235 1.06117 .97586 1.02474 42 19 .84856 1.17846 .87904 1.13761 .91046 1.09834 .94290 1.06056 .97643 1.02414 41 20 .84906 1.17777 .87955 1.13694 .91099 1.09770 .94345 1.05994 .97700 1.02355 40 21 .84956 1.17708 .88007 1.13627 .91153 1.09706 .94400 1.05932 .97756 1.02295 39 22 .85006 1.17638 .88059 1.13561 .91206 1.09642 .94455 1.05870 .97813 1.02236 38 23 .85057 1.17569 .88110 1.13494 .91259 1.09578 .94510 1.05809 .97870 1.02176 37 24 .85107 1.17500 .88162 1.13428 .91313 1.09514 .94565 1.05747 .97927 1.02117 36 25 .85157 1.17430 .88214 1.13361 .91366 1.09450 .94620 1.05685 .97984 1.02057 35 26 .85207 1.17361 .88265 1.13295 .91419 1.09386 .94676 1.05624 .98041 1.01998 34 27 .85257 1.17292 .88317 1.13228 .91473 1.09322 .94731 1.05562 .98098 1.01939 33 28 .85308 1.17223 .88369 1.13162 .91526 1.09258 .94786 1.05501 .98155 1.01879 32 29 .85358 1.17154 .88421 1.13096 .91580 1.09195 .94841 1.05439 .98213 1.01820 31 30 .85408 1.17085 .88473 1.13029 .91633 1.09131 .94896 1.05378 .98270 1.01761 30 31 .85458 1.17016 .88524 1.12963 .91687 1.09067 .94952 1.05317 .98327 1.01702 29 32 .85509 1.16947 .88576 1.12897 .91740 1.09003 .95007 1.05255 .98384 1.01642 28 33 .85559 1.16878 .88628 1.12831 .91794 1.08940 .95062 1.05194 .98441 1.01583 27 34 .85609 1.16809 .88680 1.12765 .91847 1.08876 .95118 1.05133 .98499 1.01524 26 35 .85660 1.16741 .88732 1.12699 .91901 1.08813 .95173 1.05072 .98556 1.01465 25 36 .85710 1.16672 .88784 1.12633 .91955 1.08749 .95229 1.05010 .98613 1.01406 24 37 .85761 1.16603 .88836 1.12567 .92008 1.08686 .95284 1.04949 .98671 1.01347 23 38 .85811 1.16535 .88888 1.12501 .92062 1.08622 .95340 1.04888 .98728 1.01288 22 39 .85862 1.16466 .88940 1.12435 .92116 1.08559 .95395 1.04827 .98786 1.01229 21 40 .85912 1.16398 .88992 1.12369 .92170 1.08496 .95451 1.04766 .98843 1.01170 20 41 .85963 1.16329 .89045 1.12303 .92224 1.08432 .95506 1.04705 .98901 1.01112 19 42 .86014 1.16261 .89097 1.12238 .92277 1.08369 .95562 1.04644 .98958 1.01053 18 43 .86064 1.16192 .89149 1.12172 .92331 1.08306 .95618 1.04583 .99016 1.00994 17 44 .86115 1.16124 .89201 1.12106 .92385 1.08243 .95673 1.04522 .99073 1.00935 16 45 .86166 1.16056 .89253 1.12041 .92439 1.08179 .95729 1.04461 .99131 1.00876 15 46 .86216 1.15987 .89306 1.11975 .92493 1.08116 .95785 1.04401 .99189 1.00818 14 47 .86267 1.15919 .89358 1.11909 .92547 1.08053 .95841 1.04340 .99247 1.00759 13 48 .86318 1.15851 .89410 1.11844 .92601 1.07990 .95897 1.04279 .99304 1.00701 12 49 .86368 1.15783 .89463 1.11778 .92655 1.07927 .95952 1.04218 .99362 1.00642 11 50 .86419 1.15715 .89515 1.11713 .92709 1.07864 .96008 1.04158 .99420 1.00583 10 51 .86470 1.15647 .89567 1.11648 .92763 1.07801 .96064 1.04097 .99478 1.00525 9 52 .86521 1.15579 .89620 1.11582 .92817 1.07738 .96120 1.04036 .99536 1.00467 8 53 .86572 1.15511 .89672 1.11517 .92872 '1.07676 .96176 1.03976 .99594 1.00408 7 54 .86623 1.15443 .89725 1.11452 .92926 1.07613 .96232 1.03915 .99652 1.00350 6 55 .86674 1.15375 .89777 1.11387 .92980 1.07550 .96288 1.03855 .99710 1.00291 5 56 .86725 1.15308 .89830 1.11321 .93034 1.07487 .96344 1.03794 .99768 1.00233 4 57 .86776 1.15240 .89883 1.11256 .93088 1.07425 .96400 1.03734 .99826 1.00175 3 58 .86827 1.15172 .89935 1.11191 .93143 1.07362 .96457 1.03674 .99884 1.00116 2 59 .86878 1.15104 .89988 1.11126 .93197 1.07299 .96513 1.03613 .99942 1.00058 1 60 .86929 1.15037 .90040 1.11061 .93352 1.07237 .96569 1.03553 1.00000 1.00000 0 / Cotang Tang Cotang Tang Cotang Tang Cotang Tang Cotang Tang / 49° 48° 47° 46° 45° logarithmic tables. 473 LOGARITHMIC TABLES. rp m iPfth°and e folumn headS P (')i opposite 'the latter, and under the proper 2l® find the desired logarithmic sine, cosine, tangent, or cotangent. in the sine, cosine, tangent, or cotangent ^TnTincfthe L^MrUhmi^Rnictio^s^or an Angle Containing Degrees, Minutes, and c j Tt'ind the logarithm for the degrees and minutes in the manner given Seconds.— Find me logantnm , ded ,? d ta ke the number next below the lo^Mithm^hus fo^d-^Mer toda^tglumn^ea e^ y prope^vate/n^ he foun^^yJ^w^ating^etweeii^the^TOlues^gyra. ina+°CphS S " ^4to%6° C tog T io7a C ^ log COtg a log tang a + Cpl. T. _ — COMMON LOGARITHMS OF NUMBERS. To. Log. No.! Log. No. Log. 0 — 00 20 30 103 40 60 206 1 00 000 21 32 222 41 61 278 2 30 103 22 34 242 42 62 325 3 47 712 23 36 173 43 63 347 4 60 206 24 38 021 44 64 345 5 69 897 25 39 794 45 65 321 6 77 815 26 41 497 46 66 276 7 84 510 27 43 136 47 67 210 8 90 309 28 44 716 48 68 124 9 95 424 29 46 240 49 69 020 10 00 000 30 47 712 50 69 897 11 04 139 31 49 136 51 70 757 12 07 918 32 50 515 52 71 600 13 11 394 33 51 851 53 72 428 14 14 613 34 53 148 54 73 239 15 17 609 35 54 407 55 74 036 16 20 412 36 55 630 56 74 819 17 23 045 37 56 820 57 75 587 18 25 527 38 57 978 58 76 343 19 27 875 39 59 106 59 77 085 20 30 103 40 60 206 60 77 815 No. 60 61 ' 62 68 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 Log. 77 815 78 533 79 239 79 934 80 618 81 291 81 954 82 607 83 251 83 885 84 510 85 126 85 733 86 332 86 923 87 506 88 081 88 649 89 209 89 763 90 309 No. Log. 80 90 309 81 90 849 82 91 381 83 91 908 84 92 428 85 92 942 86 93 450 87 93 952 88 94 448 89 94 939 90 95 424 91 95 904 92 96 379 93 96 848 94 97 313 95 97 772 96 98 227 97 98 677 98 99 123 99 99 564 100 00 000 474 LOGARITHMS. N. L. 0 , T 3 4 5 6 ' 7 8 9 P. P. too 00 000 043 087 130 173 217 260 303 346 389 101 432 475 518 561 604 647 689 732 775 817 44 43 42 102 860 903 945 988 *030 *072 *115 *157 *199 *242 A A A S A 9 103 01 284 326 368 410 452 494 536 578 620 662 X 2 A. A 8.8 4.0 8.6 8.4 104 703 745 787 828 870 912 953 995 *036 *078 3 13.2 12.9 12.6 105 02 119 160 202 243 284 325 366 407 449 490 4 17.6 17.2 16.8 106 531 572 612 653 694 735 776 816 857 898 5 22.0 21.5 21.0 107 938 979 *019 *060 *100 *141 *181 *222 *262 *302 6 7 26.4 30 8 25.8 30.1 25.2 29 4 108 03 342 383 423 463 503 543 583 623 663 703 1 8 35^2 34.4 33^6 109 743 ■ 782 822 862 902 941 981 *021 *060 *100 9 39.6 38.7 37.8 110 04 139 179 218 258 297 336 376 415 454 493 111 532 571 610 650 689 727 766 805 844 883 41 40 39 112 922 961 999 *038 *077 *115 *154 *192 *231 *269 A 1 a n *» Q 113 05 308 346 385 423 461 500 538 576 614 652 X 2 T. 1 8.2 8.0 O.i/ 7.8 114 690 729 767 805 843 881 918 956 994 *032 3 12.3 12.0 11.7 115 06 070 108 145 183 221 258 296 333 371 408 4 16.4 16.0 15.6 116 446 483 521 558 595 633 670 707 744 781 5 20.5 20.0 19.5 117 819 856 893 930 967 *004 *041 *078 *115 *151 6 7 24.6 28.7 24.0 28.0 23.4 27.3 118 07 188 225 262 298 335 372 408 445 482 518 1 8 32.8 32.0 31.2 119 555 591 628 664 700 737 773 809 846 882 9 36.9 36.0 35.1 120 918 954 990 *027 *063 *099 *135 *171 *207 *243 121 08 279 314 350 386 422 458 493 529 565 600 38 37 36 122 636 672 707 743 778 814 849 884 920 955 x 3.8 3.7 3.6 123 991 *026 *061 *096 *132 *167 *202 *237 *272 *307 2 7.6 7!4 7.2 124 09 342 377 412 447 482 517 552 587 621 656 3 11.4 11.1 10.8 125 691 726 760 795 830 864 899 934 968 *003 4 15.2 14.8 14.4 126 10 037 072 106 140 175 209 243 278 312 346 5 19.0 18.5 18.0 127 380 415 449 483 517 551 585 619 653 687 6 7 22.8 26.6 22.2 25.9 21. (> 25.2 128 721 755 789 823 857 890 924 958 992 *025 8 30^4 29 6 28^ 129 11 059 093 126 160 193 227 261 294 327 361 9 34.2 33.3 32.4 130 394 428 461 494 528 561 594 628 661 694 131 727 760 793 826 860 893 926 959 992 *024 35 34 33 132 12 057 090 123 156 189 222 254 287 320 352 1 3.5 3.4 3.3 133 385 418 450 483 516 548 581 613 646 678 2 7!o 6*8 6^6 134 710 743 775 808 840 872 905 937 969 *001 3 10.5 10.2 9.9 135 13 033 066 098 130 162 194 226 258 290 322 4 14.0 13.6 13.2 136 354 386 418 450 481 513 545 577 609 640 5 17.5 17.0 *)A A 16.5 TOO 137 672 704 735 767 799 830 862 893 925 956 6 7 21.0 24.5 zU.4 23.8 19.0 23.1 138 988 *019 *051 *082 *114 *145 *176 *208 *239 *270 8 28^0 27.2 26^4 139 14 301 333 364 395 426 457 489 520 551 582 9 31.5 30.6 29.7 140 613 644 675 706 737 768 799 829 860 891 141 922 953 983 *014 *045 *076 *106 *137 *168 *198 32 31 30 142 15 229 259 290 320 351 381 412 442 473 503 1 3.2 3.1 3.0 143 534 564 594 625 655 685 715 746 776 806 2 6^4 6^2 6^0 144 836 866 897 '927 957 987 *017 *047 *077 *107 3 9.6 9.3 9.0 145 16 137 167 197 227 256 286 316 346 376 406 4 12.8 12.4 12.0 146 435 465 495 524 554 584 613 643 673 702 5 16.0 15.5 15.0 147 732 761 791 820 850 879 909 938 967 997 6 7 19.2 22.4 18.6 21.7 18.0 21.0 148 17 026 056 085 114 143 173 202 231 260 289 8 25^6 24^8 24^0 149 319 348 377 406 435 464 493 522 551 580 9 28.8 27.9 27.0 150 609 638 667 696 725 754 782 811 840 869 N. L. 0 1 2 3 4 5 6 7 8 9 P. P. LOGARITHMS. 475 N. L. 0 1 2 3 4 5 6 7 8 9 P.P • 150 1 7 609 638 667 696 725 754 782 811 840 869 151 898 926 955 984 * <013 * <041 * *070 =< <099 * *127 * *156 29 28 152 .8 184 213 241 270 298 327 355 384 412 441 i 2.9 2.8 153 469 498 526 554 583 611 639 667 696 724 2 5.8 5.6 154 752 780 808 837 865 893 921 949 977 * *005 3 8.7 8.4 155 L 9 033 061 089 117 145 173 201 229 257 285 4 11.6 1 A 11.2 110 156 312 340 368 396 424 451 479 507 535 562 5 6 14.0 17.4 16.8 157 590 618 645 673 700 728 756 783 811 838 7 20.3 19.6 158 866 893 921 948 976 *003 5 *030 * *058 5 *085 5 *112 8 23.2 22.4 159 20 140 167 194 222 249 276 303 330 358 385 9 26.1 25.2 160 412 439 466 493 520 548 575 602 629 656 161 683 710 737 763 790 817 844 871 898 925 27 26 162 952 978 *005 *032 *059 *085 : *112 = *139 : *165 : *192 1 2.7 2.6 163 21 219 245 272 299 325 352 378 405 431 458 2 5.4 5.2 164 484 511 537 564 590 617 643 669 696 722 3 8.1 7.8 165 748 775 801 827 854 880 906 932 958 985 4 10.8 IQ C 10.4 IQ ft 166 22 Oil 037 063 089 115 141 167 194 220 246 5 6 lo.D 16.2 lo.u 15.6 167 272 298 324 350 376 401 427 453 479 505 7 18.9 18.2 168 531 557 583 608 634 660 686 712 737 763 8 21.6 20.8 169 789 814 840 866 891 917 943 968 994 *019 9 24.3 23,4 170 23 045 070 096 121 147 172 198 223 249 274 171 300 325 350 376 401 426 452 477 502 528 25 172 553 578 603 629 654 679 704 729 754 779 1 2.5 173 805 830 855 880 905 930 955 980 *005 *030 2 5.0 174 24 055 080 105 130 155 180 204 229 254 279 3 7.5 175 304 329 353 378 403 428 452 477 502 527 4 10.0 1 o K 176 551 576 601 625 650 674 699 724 748 773 O 6 LA.O 15.0 .177 797 822 846 871 895 920 944 969 993 *018 7 17.5 178 25 042 066 091 115 139 164 188 212 237 261 8 20.0 179 285 310 334 358 382 406 431 455 479 503 9 22.5 180 527 551 575 600 624 648 672 696 720 744 181 768 792 816 840 864 888 912 935 959 983 24 23 182 26 007 031 055 079 102 126 150 174 198 221 1 2.4 2.3 ! 183 245 269 293 316 340 364 387 411 435 458 2 4.8 4.6 184 482 505 529 553 576 600 623 647 670 694 3 7.2 6.9 185 717 741 764 788 811 834 858 881 905 928 4 K 9.6 9.2 11.5 186 951 975 998 *021 *045 *068 *091 *114 *138 *161 o 6 LA .v 14.4 13^8 187 27 184 : 207 231 254 277 300 323 346 370 393 7 16.8 16.1 188 416 - 439 462 485 508 531 554 577 600 623 8 19.2 18.4 189 646 1 669 692 715 738 761 784 807 830 852 9 21.6 20.7 190 875 > 898 921 944 967 989 *012 *035 *058 *081 191 28 102 ; 126 149 171 194 217 240 262 285 307 22 2! 192 33 C > 353 375 398 421 443 466 488 511 533 1 2.2 2.1 193 | 55 ( > 578 601 623 646 668 691 713 735 758 2 4.4 4.2 194 78 C ) 803 825 847 870 892 914 937 959 981 3 66 6.3 195 29 002 5 026 048 070 092 115 137 159 181 203 4 8.8 11.0 8.4 10.5 196 226 > 248 270 292 314 336 358 380 403 425 o 6 13.2 12.6 197 1 469 491 513 535 557 579 601 623 645 7 15.4 14.7 198 66 - 1 688 710 732 754 776 798 820 842 863 8 17.6 16.8 199 882 > 907 929 951 973 994 *016 *038 *060 *081 9 19.8 18.9 200 30 102 J 125 146 168 190 211 233 255 276 298 N. L.O 1 2 3 4 5 6 1 7 8 9 P. P. 476 LOGARITHMS . N. L. 0 1 2 3 4 5 6 7 8 9 P. P. 200 30 103 125 146 168 190 211 233 255 276 298 22 21 1 2.2 2.1 2 4.4 4.2 3 6.6 6.3 4 8.8 8.4 5 11.0 10.5 - 6 13.2 12.6 7 15.4 14.7 8 17.8 16.8 9 19.8 18.9 20 1 2.0 2 4.0 3 6.0 4 8.0 5 10.0 6 12.0 7 14.0 8 16.0 9 18.0 19 1 1.9 2 3.8 3 5.7 4 7.6 5 9.5 6 11.4 7 13.3 8 15.2 9 17.1 18 1 1.8 2 3.6 3 5.4 4 7.2 5 9.0 6 10.8 7 12.6 8 14.4 9 16.2 17 1 1.7 2 34 3 5.1 4 6.8 5 8.5 6 10.2 7 11.9 ! 8 13.6 9 15.3 201 202 203 204 205 206 207 208 209 210 320 535 750 963 31 175 387 597 806 32 015 341 557 771 984 197 408 618 827 035 363 578 792 *006 218 429 639 848 056 384 600 814 *027 239 450 660 869 077 406 621 835 *048 260 471 681 890 098 428 643 856 *069 281 492 702 911 118 449 664 878 *091 302 513 723 931 139 471 685 899 *112 323 534 744 952 160 492 707 920 *133 345 555 765 973 181 514 728 942 *154 366 576 785 994 201 222 243 263 284 305 325 346 366 387 408 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 428 634 838 33 041 244 445 646 846 34 044 449 654 858 062 264 465 666 866 064 469 675 879 082 284 486 686 885 084 490 695 899 102 304 506 706 905 - 104 510 715 919 122 325 526 726 925 124 531 736 940 143 345 546 746 945 143 552 756 960 163 365 566 766 965 163 572 777 980 183 385 586 786 985 183 593 797 *001 203 405 606 806 *005 203 613 818 *021 224 425 626 826 *025 223 242 262 282 301 321 341 361 380 400 420 439 635 830 35 025 218 411 603 793 984 459 655 850 044 238 430 622 813 *003 479 674 869 064 257 449 641 832 *021 498 694 889 083 276 468 660 851 *040 518 713 908 102 295 488 679 870 *059 537 733 928 122 315 507 698 889 *078 557 753 947 141 334 526 717 908 *097 577 772 967 160 353 545 736 927 *116 596 792 986 180 372 564 755 946 *135 616 811 *005 199 392 583 774 965 *154 36 173 192 211 229 248 267 286 305 324 342 361 549 736 922 37 107 291 475 658 840 380 568 754 940 125 310 493 676 858 399 586 773 959 144 328 511 694 876 418 605 791 977 162 346 530 712 894 436 624 810 996 181 365 548 731 912 455 642 829 *014 199 383 566 749 931 474 661 847 *033 218 401 585 767 949 493 680 866 *051 236 420 603 785 967 511 698 884 *070 254 438 621 803 985 530 717 903 *088 273 457 639 822 *003 38 021 039 057 075 093 112 130 148 166 184 202 382 561 739 917 39 094 270 445 ! 62 C ! 220 ; 399 578 i 757 934 111 » 287 > 463 1 637 238 417 596 775 952 129 305 480 655 256 435 614 792 970 146 322 498 672 274 453 632 810 987 164 340 515 690 292 471 650 828 *005 182 358 533 707 310 489 ■ 668 846 *023 199 375 550 724 328 507 686 863 *041 217 393 568 742 346 525 703 881 *058 235 410 585 759 364 543 721 899 *076 252 428 602 777 794 t 811 829 846 863 881 898 915 933 950 K. L.O 1 2 3 4 5 6 7 8 9 P.P. LOGARITHMS. 477 N. L.O 1 2 3 4 5 6 7 8 9 P. P. 250 : 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 •‘277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 59 794 811 829 846 863 881 898 915 933 950 18 1 1.8 2 3.6 3 5.4 4 7.2 5 9.0 6 10.8 7 12.6 8 14.4 9 16.2 17 1 1.7 2 3.4 3 5.1 4 6.8 5 8.5 6 10.2 7 11.9 8 13.6 9 15.3 16 1 1.6 2 3.2 3 4.8 4 6.4 5 8.0 6 9.6 7 11.2 8 12.8 9 14.4 15 1 1.5 2 3.0 3 4.5 4 6.0 5 7,5 6 9.0 7 10.5 8 12.0 9 13.5 14 1 1.4 2 2 8 3 4.2 4 5.6 5 7.0 6 8.4 7 9.8 8 11.2 9 12.6 967 10 140 312 483 654 824 993 41 162 330 985 157 329 500 671 841 *010 179 347 *002 175 346 518 688 858 *027 196 363 *019 192 364 535 705 875 *044 212 380 *037 209 381 552 722 892 *061 229 397 *054 5 226 398 569 739 909 *078 : 246 414 *071 5 243 415 586 756 926 *095 ; 263 430 *088 s 261 432 603 773 943 *111 : 280 447 *106 5 278 449 620 790 960 *128 ; 296 464 *123 295 466 637 807 976 *145 313 481 497 514 531 547 564 581 597 614 631 647 664 830 996 42 160 325 488 651 813 975 681 | 847 *012 177 341 504 667 830 991 697 863 *029 193 357 521 684 846 *008 714 880 *045 210 374 537 700 862 *024 731 896 *062 226 390 553 716 878 *040 747 913 *078 243 406 570 732 894 *056 764 929 *095 259 423 586 749 911 *072 780 946 *111 275 439 602 765 927 *088 797 963 *127 292 455 619 781 943 *104 814 979 *144 308 472 635 797 959 *120 43 136 152 169 185 201 217 233 249 265 281 297 457 616 775 933 44 091 248 404 560 313 473 632 791 949 107 264 420 576 329 489 648 807 965 122 279 436 592 345 505 664 823 981 138 295 • 451 607 361 521 680 838 996 154 311 467 623 377 537 696 854 *012 170 326 483 638 393 553 712 870 *028 185 342 498 654 409 569 * 727 886 *044 201 358 514 669 425 584 743 902 *059 217 373 529 685 441 600 759 917 *075 232 389 545 700 716 731 747 762 778 793 809 824 840 855 871 45 025 179 332 484 637 788 939 46 090 886 040 194 347 500 652 803 954 i 105 902 056 209 362 515 667 818 969 120 917 071 225 378 530 682 834 984 135 932 086 240 393 545 697 849 *000 150 948 102 255 408 561 712 864 *015 165 963 117 271 423 576 728 879 *030 180 979 133 286 439 591 743 894 *045 195 994 148 301 454 606 758 909 *060 210 *010 163 317 469 621 773 924 *075 225 240 i 255 270 285 300 315 330 345 359 374 380 538 m 835 982 47 120 27 1 422 567 > 404 i 553 ' 702 > 850 5 997 ) 144 5 290 > 436 I 582 419 568 716 864 *012 159 305 451 596 434 583 731 879 *026 173 319 465 611 449 598 746 894 *041 188 334 480 625 464 613 761 909 *056 202 349 494 640 479 627 776 923 *070 217 363 509 654 494 642 790 938 *085 232 378 524 669 509 657 805 953 . *100 246 392 538 683 523 672 820 967 *114 261 407 553 698 712 2 727 741 756 770 784 799 813 828 842 N. L.O 1 2 3 4 5 6 7 8 9 P. P. 478 LOGARITHMS. N. L.oj 1 2 3 4 5 6 7 8 9 p. P. 300 47 712 727 741 756 770 784 799 813 828 842 301 857 871 885 900 914 929 943 958 972 986 302 48 001 015 029 044 058 073 087 101 116 130 303 144 159 173 187 202 216 230 244 259 273 304 287 302 316 330 344 359 373 387 401 416 15 305 430 444 458 473 487 501 515 530 544 558 306 572 586 601 615 629 643 657 671 686 700 1 1.5 307 714 728 742 756 770 785 799 813 827 841 2 3.0 308 855 869 883 897 911 926 940 954 968 982 3 A 4.5 a n 309 996 *010 *024 *038 *052 *066 *080 *094 *108 *122 4 5 o.u 7.5 310 49 136 150 104 178 192 206 220 234 248 262 7 | 9.0 10.5 311 276 290 304 318 332 346 360 374 388 402 8 9 j 12.0 13.5 312 415 429 443 457 471 485 499 513 527 541 313 554 568 582 596 610 624 638 651 665 679 314 693 707 721 734 748 762 776 790 803 817 315 831 845 859 872 886 900 914 927 941 955 14 316 969 982 996 *010 *024 *037 *051 *065 *079 *092 317 50 106 120 133 147 161 174 188 202 215 229 1 1.4 318 243 256 270 284 297 311 325 338 352 365 2 2.8 319 379 393 406 420 433 447 461 474 488 501 3 4 4.2 5.6 320 515 529 542 556 569 583 596 610 623 | 637 5 6 7.0 8.4 321 651 664 678 691 705 718 732 745 759 772 7 g 9.8 11.2 322 786 799 813 S 2 & 840 853 866 880 893 907 9 12^ 1 \ - 323 920 934 947 961 974 987 *001 *014 *028 *041 324 51 0551 068 081 095 108 121 135 148 162 175 325 188 202 215 228 242 255 268 282 295 308 326 322 335 348 362 375 388 402 415 428 441 13 327 455 468 481 495 508 521 534 548 561 574 328 587 601 614 627 640 654 667 680 693 706 1 1.3 329 720 733 746 759 772 786 799 812 825 838 2 3 2.6 3.9 330 851 865 878 891 904 917 930 943 957 970 4 5 5 2 6.5 331 983 996 *009 *022 *035 *048 *061 *075 *088 *101 6 7.8 Q 1 332 52 114 127 140 153 166 179 192 205 218 231 7 g 10.4 333 244 257 270 284 297 310 323 336 349 362 9 11.7 334 375 388 401 414 427 440 453 466 479 492 335 504 517 530 543 556 569 582 595 608 621 336 634 S 647 660 673 686 699 711 724 737 750 337 763 ; 776 789 802 815 827 840 853 866 879 12 338 892 : 905 917 930 943 956 969 982 994 *007 339 53 020 | 033 046 058 071 084 097 | 110 122 135 1 t) 1.2 O I 340 148 1 161 173 186 199 212 224 237 250 263 L 3 i A.T 3.6 A W 311 275 | 288 301 314 326 339 352 364 377 390 4 5 4.0 6.0 342 403 ! 415 428 441 453 466 479 491 504 517 6 7.2 343 529 ! 542 555 567 580 593 605 . 618 631 m 7 g 8.4 9.6 344 656 ; 668 681 694 706 719 732 744 757 769 9 10.8 345 782 794 807 820 832 845 857 870 882 895 346 908 920 933 945 958 970 983 995 *008 *020 347 54 033 045 058 070 083 095 108 120 133 145 348 158 170 183 195 208 220 233 245 258 270 349 283 295 307 320 332 345 357 370 382 394 350 407 419 432 444 456 469 481 494 506 518 N. L 0 1 2 3 4 5 6 7 8 9 P. P. LOGARITHMS. 479 N. L. 0 1 2 3 4 5 6 7 8 9 P. P. 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 54 407 419 432 444 456 469 481 494 506 518 13 1 1.3 2 2.6 3 3.9 4 5.2 5 6.5 6 7.8 ' 7 9.1 8 10.4 9 11.7 12 1 1.2 2 2.4 3 3.6 4 4.8 5 6.0 6 7,2 7 8.4 8 9.6 9 10.8 II 1 1.1 2 2.2 3 3.3 4 4.4 5 5.5 6 6.6 7 7.7 8 8.8 9 9.9 10 1 1.0 2 2,0 3 3.0 4 4.0 5 5.0 6 6.0 7 7.0 8 8.0 9 9.0 531 654 777 900 55 023 145 267 388 509 543 667 790 913 035 157 279 400 522 555 679 802 925 047 169 291 413 534 568 691 814 937 060 182 303 425 546 580 704 827 949 072 194 315 437 558 593 716 839 962 084 206 328 449 570 605 728 851 974 096 218 340 461 582 617 741 864 986 108 230 352 473 594 630 753 876 998 ! 121 242 364 485 606 642 765 888 *011 133 255 376 497 618 630 642 654 666 678 691 703 715 727 739 751 871 991 56 110 229 348 467 585 703 763 883 *003 122 241 360 478 597 714 775 895 *015 134 253 372 490 608 726 787 907 *027 146 265 384 502 620 738 799 919 *038 158 277 396 514 632 750 811 931 *050 170 289 407 526 644 761 823 943 *062 182 301 419 538 656 773 835 955 *074 194 312 431 549 667 785 847 967 *086 205 324 443 561 679 797 859 979 *098 217 336 455 573 691 808 820 832 844 855 867 879 891 902 914 926 937 57 054 171 287 * 403 519 634 749 864 949 066 183 299. 415 530 646 761 875 961 078 194 310 426 542 657 772 887 972 089 206 322 438 553 669 784 898 984 101 217 334 449 565 680 795 910 996 113 229 345 461 576 692 807 921 *008 124 241 357 473. 588 703 818 933 *019 136 252 368 484 600 715 830 944 *031 148 264 380 496 611 726 841 955 *043 159 276 392 507 623 738 852 967 978 990 *001 *013 *024 *035 *047 *058 *070 *081 58 092 206 320 433 546 659 771 883 995 104 218 331 444 557 670 782 894 *006 115 229 343 456 569 •681 794 906 *017 127 240 354 467 580 692 805 917 *028 138 252 365 478 591 704 816 928 *040 149 263 377 490 602 715 827 939 *051 161 274 388 501 614 726 838 950 *062 172 286 399 512 625 737 850 961 *073 184 297 410 524 636 749 861 973 *084 195 309 422 535 647 760 872 984 *095 59 106 118 129 140 151 162 173 184 195 207 218 329 439 55C 66C 77C 87? m 60 229 340 450 l 561 1 671 1 780 ) 890 5 999 ’ 108 240 351 461 572 682 791 901 *010 119 251 362 472 583 693 802 912 *021 130 262 373 483 594 704 813 923 *032 141 273 384 494 605 715 824 934 *043 152 284 395 506 616 726 835 945 *054 163 295 406 517 627 737 846 956 *065 173 306 417 528 638 748 857 966 *076 184 318 428 539 649 759 868 977 *086 195 20( 3 217 228 239 249 260 271 282 293 304 N. L. 0 1 2 3 4 5 6 7 8 9 P. P. 480 LOGARITHMS. N. L 0 | 1 2 3 4 5 6 7 8 9 P. P. 400 50 206 217 228. 239 249 260 271 282 293 304 401 314 325 336 347 358 369 379 390 401 412 402 423 433 444 455 466 477 487 498 509 520 403 531 541 552 563 574 584 595 606 617 627 404 638 649 660 670 681 692 703 713 724 735 405 746 756 767 778 788 799 810 821 831 842 406 853 863 874 885 895 906 917 927 938 949 H 407 959 970 981 991 *002 *013 *023 *034 *045 *055 408 61 066 077 087 098 109 119 130 140 151 162 l i.i 409 172 183 194 204 215 225 236 247 257 268 2 3 2.2 3.3 410 278 289 300 310 321 331 342 352 363 374 4 5 4.4 5.5 411 384 395 405 416 426 437 448 458 469 479 6 6.6 412 490 500 511 521 532 542 553 563 574 584 7 g 7.7 8.8 413 595 606 616 627 637 648 658 669 679 690 9 9!9 414 700 711 721 731 742 752 763 773 784 794 415 805 815 826 836 847 857 868 878 888 899 416 909 920 930 941 951 962 972 982 993 *003 417 62 014 024 034 045 055 066 076 086 097 107 418 118 128 138 149 159 170 180 190 201 211 419 221 232 242 252 263 273 284 294 304 315 420 325 335 346 356 366 377 387 397 408 418 10 421 428 439 449 459 469 480 490 500 511 521 1 422 531 542 552 562 572 583 593 603 613 624 1 ! o ! 1.0 423 634 644 655 665 675 685 696 706 716 726 3 z .u 3.0 424 737 747 757 767 778 788 | 798 808 818 829 4.0 425 839 849 859 87C 880 890 | 900 910 921 931 5 5.0 426 941 951 961 972 982 992 *002 *012 *022 *033 6 : 6.0 427 63 043 053 063 073 083 094 104 114 124 134 7 Q i 7.0 Q A 428 144 155 165 175 185 195 205 215 225 236 O 9 j o.U ! 9.0 429 246 256 266 276 286 296 306 317 327 337 1 430 347 357 367 377 387 397 407 417 428 438 431 448 458 468 478 488 498 508 518 528 538 432 548 558 568 579 589 599 609 619 629 639 433 649 659 669 679 689 699 709 719 729 739 434 749 759 769 779 789 799 809 819 829 839 435 849 859 869 879 889 899 909 919 929 939 Q 436 949 959 969 979 988 998 *008 *018 *028 *038 437 64 048 058 068 078 088 098 108 118 J.28 137 i 0.9 438 147 157 167 177 187 197 207 217 227 237 2 1.8 439 246 256 266 276 286 296 306 316 326 335 3 A 2.7 q 440 345 355 365 375 385 395 404 414 424 434 * 5 A 0.0 4.5 K A 441 444 454 464 473 483 493 503 513 523 532 D 7 O.T 6.3 442 542 ; 552 562 572 582 591 601 611 621 631 8 Q 7.2 Q 1 443 640 1 650 660 670 680 689 699 709 719 729 0.1 444 738 , 748 758 768 777 787 797 807 816 826 445 836 I 846 856 865 875 885 895 904 914 924 446 933 ; 943 953 963 972 982 992 *002 *011 *021 447 65 031 040 050 060 070 079 089 099 108 118 448 128 1 137 147 157 167 176 186 196 205 215 449 225 > 234 244 254 263 273 283 292 302 312 450 321 . 331 341 350 360 369 379 389 398 408 N. L. 0 1 2 3 4 5 6 t-r i 8 9 p. p. LOGARITHMS . 481 N. L. 0 1 2 3 4 5 6 7 8 9 P. P. 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 35 321 331 341 350 360 369 379 389 398 408 10 1 1.0 2 2.0 3 3.0 4 4.0 5 5.0 6 6.0 7 7.0 8 8.0 9 9.0 9 1 0.9 2 1.8 3 2.7 4 3.6 5 4.5 6 5.4 7 6.3 8 7.2 9 8.1 8 1 0.8 2 1.6 3 2.4 4 3.2 5 4.0 6 4.8 j 7 5.6 8 6.4 9 7.2 418 514 610 706 801 896 992 36 087 181 427 523 619 715 811 906 *001 096 191 437 533 629 725 820 916 *011 106 200 447 543 639 734 830 925 *020 115 210 456 552 648 744 839 935 *030 124 219 466 562 658 753 849 944 *039 134 229 475 571 667 763 858 954 *049 : 143 238 485 581 677 772 868 963 *058 153 247 495 591 686 782 877 973 *068 162 257 504 600 696 792 887 982 *077 172 266 276 285 295 304 314 323 332 342 351 361 370 464 558 652 745 839 932 67 025 117 380 474 567 661 755 848 941 034 127 389 483 577 671 764 857 950 043 136 398 492 586 680 773 867 960 052 145 408 502 596 689 783 876 969 062 154 417 511 605 699 792 885 978 071 164 427 521 614 708 801 894 987 080 173 436 530 624 717 811 904 997 089 182 445 539 633 727 820 913 *006 099 191 455 549 642 736 829 922 *015 108 201 210 219 228 237 247 256 265 274 284 293 302 394 486 578 669 761 852 943 68 034 311 403 495 587 679 770 861 952 043 321 413 504 596 688 779 870 961 052 330 422 514 605 697 788 879 970 061 339 431 523 614 706 797 888 979 070 348 440 532 624 715 806 897 988 079 357 449 541 633 724 815 906 997 088 367 459 550 642 733 825 916 *006 097 376 468 560 651 742 834 925 *015 106 385 477 569 660 752 843 934 *024 115 124 133 142 151 160 169 178 187 196 205 215 305 395 485 574 664 753 842 931 224 314 404 494 583 673 762 851 940 233 323 413 502 592 681 771 860 949 242 332 422 511 601 690 780 869 958 251 341 431 520 610 699 789 878 966 260 350 440 529 619 708 797 886 975 269 359 449 538 628 717 806 895 984 278 368 458 547 637 726 815 904 993 287 377 467 556 646 735 824 913 *002 296 386 476 565 655 744 833 922 *011 69 020 028 037 046 055 064 073 082 090 099 108 197 285 373 461 548 636 722 81 C 117 205 294 ; 381 469 l 557 i 644 ; 732 1 819 126 214 302 390 478 566 653 740 827 135 223 311 399 487 574 662 749 836 144 232 320 408 496 583 671 758 845 152 241 329 417 504 592 679 767 854 161 249 338 425 513 601 688 775 862 170 258 346 434 522 609 697 784 871 179 267 355 443 531 618 705 793 880 188 276 364 452 539 627 714 801 888 897 r 906 914 923 932 940 949 958 966 975 N. L. 0 1 2 3 4 5 6 7 8 9 P. P. 482 LOGARITHMS. N. L. 0 1 2 3 4 5 6 7 8 9 P. P. 500 >9 897 906 914 923 1 932 940 949 958 1 966 975 9 1 0.9 2 i 1.8 3 2.7 4 3.6 5 | 4.5 6 1 5.4 7 I 6.3 8 7.2 9 | 8.1 8 1 0.8 2 1.6 3 2.4 4 3.2 5 4.0 6 4.8 7 5.6 8 6.4 9 7.2 7 | 1 0.7 2 1.4 3 2.1 4 2.8 501 502 503 504 505 506 507 508 509 984 '0 070 157 243 329 415 501 586 672 992 079 165 252 338 424 509 595 680 *001 088 174 260 346 432 518 603 689 *010 096 183 269 355 441 526 612 697 *018 105 191 278 364 449 535 621 706 *027 : 114 200 286 372 458 544 629 714 *036 : 122 209 295 381 467 552 638 723 *044 : 131 217 303 389 475 561 646 731 *053 : 140 226 312 398 484 569 655 740 *062 148 234 321 406 492 578 663 749 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 757 766 774 783 791 800 808 817 825 834 842 927 71 012 096 181 265 349 433 517 851 935 020 105 189 273 357 441 525 859 944 029 113 198 282 366 450 533 868 952 037 122 206 290 374 458 542 876 961 046 130 214 299 383 466 550 885 969 054 139 223 307 391 475 559 893 978 063 147 231 315 399 483 567 902 986 071 155 240 324 408 492 575 910 995 079 164 248 332 416 500 584 919 *003 088 172 257 341 425 508 592 600 609 617 625 634 642 650 659 667 675 684 767 850 933 72 016 099 181 263 346 692 775 858 941 024 107 189 272 354 700 784 867 950 032 115 198 280 362 709 792 875 958 041 123 206 288 370 717 800 883 966 049 132 214 296 378 725 809 892 975 057 140 222 304 387 734 817 900 983 066 148 230 313 395 742 825 908 991 ! 074 156 239 321 1 403 750 834 917 999 082 165 247 329 411 759 842 925 *008 090 173 255 337 419 428 436 444 452 460 469 477 485 493 501 509 591 673 754 835 916 997 73 078 159 518 599 681 762 843 925 *006 i 086 i 167 526 607 689 770 852 933 *014 094 175 534 616 697 779 860 941 *022 102 183 542 624 705 787 868 949 *030 111 191 550 632 713 795 876 957 *038 119 199 558 640 722 803 884 965 *046 127 207 567 648 730 811 892 973 *054 135 215 575 656 738 819 90 C 981 *062 143 223 583 | 665 j 746 I 827 908 989 1*070 151 231 239 i 247 255 263 272 280 288 296 304 312 5 3.5 6 4.2 32 C 40 C 48 C 56 C 64 C 711 791 87 * 951 1 328 ) 408 ) 488 ) 568 ) 648 ) 727 ) 807 5 886 J 965 336 416 496 576 656 735 815 894 973 344 424 504 584 664 743 823 902 981 352 432 512 592 672 751 830 910 989 360 440 520 600 679 759 838 918 997 368 448 528 608 687 767 846 926 *005 376 456 536 616 695 775 854 933 *013 384 464 544 624 703 783 862 941 *020 392 472 552 632 711 791 870 949 *028 7 4.9 8 56 9 6.3 74 03 ( 3 044 052 060 068 076 5 084 092 099 107 N L.O 1 2 9 O 4 6 7 8 9 P P. LOGARITHMS. 483 N. L. 0 1 2 3 4 5 6 7 8 9 P. R 550 74 036 044 052 060 068 076 084 092 099 107 551 115 123 131 139 147 155 162 170 178 186 552 194 202 210 218 225 233 241 249 257 265 553 273 280 288 296 304 312 320 327 335 343 554 351 359 367 374 382 390 398 406 414 421 555 429 437 445 453 461 468 476 484 492 500 556 507 515 523 531 539 547 554 562 570 578 557 586 593 601 609 617 624 632 640 648 656 558 663 671 679 687 695 702 710 718 726 733 559 741 749 757 764 772 780 788 796 803 811 560 819 827 834 842 850 858 865 873 881 889 8 561 896 904 912 920 927 935 943 950 958 966 0.8 1 .6 562 974 981 989 997 *005 *012 *020 *028 *035 *043 1 2 563 75 051 059 066 074 082 089 097 105 113 120 3 2 A I 564 128 136 143 151 159 166 174 182 189 197 4 3.2 565 205 213 220 228 236 243 251 259 266 274 5 4.0 566 282 289 297 305 312 320 328 335 343. 351 6 4.8 5.6 6.4 567 358 366 374 381 389 397 404 412 420 427 7 8 568 435 442 450 458 465 473 481 488 496 504 9 7 >2 569 511 519 526 534 542 549 557 565 572 580 570 587 595 603 610 618 626 633 641 648 656 571 664 671 679 686 694 702 709 717 724 732 572 740 747 755 762 770 778 785 793 800 808 573 815 823 831 838 846 853 861 868 876 884 574 891 899 906 914 921 929 937 944 952 959 575 967 974 982 989 997 *005 *012 *020 *027 *035 576 76 042 050 057 065 072 080 087 095 103 110 577 118 125 133 140 148 155 163 170 178 185 578 193 200 208 215 223 230 238 245 253 260 579 268 275 283 290 298 305 313 320 328 335 580 343 350 358 365 373 380 388 395 403 410 7 581 418 425 433 440 448 455 462 470 477 485 1 0.7 582 492 500 507 515 522 530 537 545 552 559 2 1.4 583 567 574 582 589 597 604 612 619 '626 634 3 2.1 584 641 649 656 664 671 678 686 693 701 708 4 2.8 3.5 4.2 585 716 723 730 738 745 753 760 768 775 782 5 6 586 790 797 805 812 819 827 834 842 849 856 7 4 i 9 587 864 871 879 886 893 901 908 916 923 930 8 5.6 588 938 945 953 960 967 975 982 989 997 *004 9 6.3 589 77 012 019 026 034 041 048 056 063 070 078 590 085 093 100 107 115 122 129 137 144 151 591 159 166 173 181 188 195 203 210 217 225 592 232 240 247 254 262 269 276 283 291 298 593 305 313 320 327 335 342 349 357 364 371 594 i 379 1 386 393 401 408 415 422 430 437 444 595 452 : 459 466 474 481 488 495 503 510 517 596 525 . 532 539 546 554 561 568 576 583 590 597 597 605 612 619 627 634 641 648 656 663 598 670 i 677 685 692 699 706 714 721 728 735 599 743 i 750 757 764 772 779 786 793 801 808 600 81c > 822 830 837 844 851 859 866 873 880 N. L 0 1 2 3 4 5 6 7 8 9 P P. 484 LOGARITHMS. N. L. 0 1 2 3 4 5 6 7 8 9 P. P. 600 77 815; 822 830 837 844 851 859 866 873 880 601 887 895 902 909 916 924 931 938 945 952 602 960 967 974 981 988 996 *003 : *010 : *017 1 *025 603 78 032 039 046 053 061 068 075 082 089 097 604 104 111 118 125 132 140 147 154 161 168 605 176 183 190 197 204 211 219 226 233 240 606 247 254 262 269 276 283 290 297 305 312 8 607 319! 326 333 340 347 355 362 369 376 383 | 608 390 ; 398 405 412 419 426 433 440 447 455 l 0.8 609 462| 469 476 483 490 497 504 512 519 526 2 : 3 1.6 2.4 610 533 540 547 554 561 569 576 583 590 597 4 5 3.2 4.0 611 604 611 618 625 633 640 647 654 661 668 6 ►7 4.8 c f; 612 675 682 689 696 704 711 718 725 732 739 7 g 0.0 6.4 613 746 753 760 767 774 781 789 796 803 810 9 7'.2 614 817 824 831 838 845 852 859 866 873 880 615 888 895 902 909 916 923 930 937 944 951 616 958 965 972 979 986 993 *000 *007 *014 *021 617 79 029 036 043 050 057 064 071 078 085 092 618 099 106 113 120 127 134 141 148 155 162 619 169 176 183 190 197 204 211 218 225 232 620 239 246 253 260 267 274 281 288 295 302 7 621 309 316 323 330 337 344 351 358 365 372 622 379 386 393 400 407 414 421 428 435 442 1 2 0.7 1.4 623 449 456 463 470 477 484 491 498 505 511 3 2*1 624 518 525 532 539 546 553 560 567 574 581 4 2.8 625 588 595 602 609 616 623 630 637 644 650 5 3.5 626 657 664 671 678 685 692 699 706 713 720 6 4.2 627 727 734 741 748 754 761 768 775 782 789 7 g 4.9 5.6 628 796 803 810 817 824 831 837 844 851 858 9 | 6.3 629 865 872 879 886 893 900 906 913 920 927 630 934 941 948 955 962 969 975 982 989 996 631 80 003 010 017 024 030 037 044 051 058 065 632 072 079 085 092 099 106 113 120 127 1 34 633 140 147 154 161 168 175 182 188 195 202 634 209 216 223 229 236 243 250 257 264 271 635 277 284 291 298 305 312 318 325 332 339 6 636 346 353 359 366 373 380 387 393 400 407 637 414 421 428 434 441 448 455 462 468 475 1 0.6 638 482 489 496 502 509 516 523 530 536 543 2 1.2 639 550 557 504 570 577 584 591 598 604 611 3 4 1.8 i 2.4 640 618 625 632 638 645 652 659 665 672 679 5 6 3.0 3 6 641 686 693 699 706 713 720 726 733 740 747 7 4.2 4 Q 642 754 760 767 774 781 787 794 801 808 814 8 9 ! 4.0 1 5.4 643 821 828 835 841 848 855 862 868 875 882 644 889 i 895 902 909 916 922 929 936 943 949 645 956 i 963 969 976 983 990 996 *003 *010 *017 646 81 023 1 030 037 043 050 057 064 070 077 084 647 090 i 097 104 111 117 124 131 137 144 151 648 158 ! 164 171 178 184 191 198 204 211 218 649 224 : 231 238 245 251 258 265 271 278 285 650 291 . 298 305 311 318 325 331 338 345 351 N. L.O 1 2 3 4 5 6 7 8 260 266 271 276 282 287 293 298 304 800 30 S 1 314 320 325 331 336 342 347 352 358 N. L. 0 1 2 3 4 5 6 7 8 9 P. P. 488 LOGARITHMS. N. L. 0 1 2 3 4 5 6 7 8 9 P. P. 800 90 309 314 320 325 331 336 342 347 352 358 801 363 369 374 380 385 390 396 401 407 412 802 417 423 428 434 439 445 450 455 461 466 803 472 477 482 488 493 499 504 509 515 520 804 526 531 536 542 547 553 558 563 569 574 805 580 585 590 596 601 607 612 617 623 628 806 634 639 644 650 655 660 666 671 677 682 807 687 693 698 703 709 714 720 725 730 736 808 741 747 752 757 763 768 773 779 784 789 809 795 800 806 811 816 822 827 832 838 843 810 849 854 859 865 870 875 881 886 891 897 6 811 902 907 913 918 924 929 934 940 945 950 812 956 961 966 972 977 982 988 993 998 *004 i o 0.6 1 0 813 91 009 014 020 025 030 036 041 046 052 057 L 3 Y.L 1.8 814 062 068 073 078 084 089 094 100 105 110 4 2.4 815 116 121 126 132 137 142 148 153 158 164 5 3.0 816 169 174 180 185 190 196 201 206 212 217 6 3.6 817 222 228 233 238 243 249 254 259 265 270 7 Q 4.2 ± a 818 275 281 286 291 297 302 307 312 318 323 O 9 5.4 819 328 334 339 344 350 355 360 365 371 376 820 381 387 392 397 403 408 413 418 424 429 821 434 440 445 450 455 461 466 471 477 482 822 487 492 498 503 508 514 519 524 529 535 823 540 545 551 556 561 566 572 577 582 587 824 593 598 603 609 614 619 624 630 635 640 825 645 651 656 661 666 672 677 682 687 693 826 698 703 709 714 719 724 730 735 740 745 827 751 756 761 766 772 777 782 787 793 798 828 803 808 814 819 824 829 834 840 845 850 829 855 861 866 871 876 882 887 892 897 903 830 908 913 918 924 929 934 939 944 950 955 5 831 960 965 971 976 981 986 991 997 *002 *007 1 0.5 832 92 012 018 023 028 033 038 044 049 054 059 2 1.0 833 065 070 075 080 085 091 096 101 106 111 3 1.5 834 117 122 127 132 137 143 148 153 158 163 4 2.0 835 169 174 179 184 189 195 200 205 210 215 5 c 2.5 9 n 836 221 226 231 236 241 247 252 257 262 267 D 7 o.u 3.5 837 273 278 283 288 293 298 304 309 314 319 8 4.0 838 324 330 335 340 345 350 355 361 366 371 9 4.5 839 376 381 387 392 397 402 407 412 418 423 840 428 433 438 443 449 454 459 464 469 474 841 480 485 490 495 500 505 511 516 521 526 842 531 536 542 547 552 557 . 562 567 572 578 843 583 588 593 598 603 609 614 619 624 629 844 634 639 645 650 655 660 665 670 675 681 845 586 ; 691 696 701 706 711 716 722 727 732 846 737 742 747 752 758 763 768 773 778 783 847 78 £ ; 793 799 804 809 814 819 824 829 834 848 84 C 1 845 850 855 860 865 870 875 881 886 849 891 . 896 901 906 911 916 921 927 932 937 850 942 1 947 952 957 962 967 973 978 983 988 N. L. 0 1 2 3 4 5 6 7 8 9 I \ P. LOGARITHMS. 483 N. L. 0 1 2 3 4 5 6 7 8 9 P. P. 850 1 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 ‘ 892 893 894 895 896 897 898 899 900 12 942 947 952 957 962 967 973 978 983 988 6 1 0.6 2 1.2 3 1.8 4 2.4 5 3.0 6 3.6 7 4.2 8 4.8 9 5.4 5 1 0.5 2 1.0 3 1.5 4 2.0 5 2,5 6 3.0 7 3.5 8 4.0 9 4.5 4 1 0.4 2 0.8 3 1.2 4 1.6 5 2.0 6 2.4 7 2.8 8 3.2 9 3.6 993 33 044 095 146 197 247 298 349 399 998 049 100 151 202 252 303 354 404 *003 054 105 156 207 258 308 359 409 *008 059 110 161 212 263 313 364 414 *013 064 115 166 217 268 318 369 420 *018 : 069 120 171 222 273 323 374 425 *024 : 075 125 176 227 278 328 379 430 *029 : 080 131 181 232 283 334 384 435 *034 : 085 136 186 237 288 339 389 440 *039 090 141 192 242 293 344 394 445 450 455 460 465 470 475 480 485 490 495 500 551 601 651 702 752 802 852 902 505 556 606 656 707 757 807 857 907 510 561 611 661 712 762 812 862 912 515 566 616 666 717 767 817 867 917 520 571 621 671 722 772 822 872 922 526 576 626 676 727 777 827 877 927 531 581 631 682 732 782 832 882 932 536 586 636 687 737 787 837 887 937 541 591 641 692 742 792 842 892 942 546 596 646 697 747 797 847 897 947 952 957 962 967 972 977 982 987 992 997 94 002 052 101 151 201 250 300 349 399 007 057 106 156 206 255 305 354 404 012 062 111 161 211 260 310 359 409 017 067 116 166 216 265 315 364 414 022 072 121 171 221 270 320 369 419 027 077 126 176 226 275 325 374 424 032 082 131 181 231 280 330 379 429 037 086 136 186 236 285 335 384 433 042 091 141 191 240 290 340 389 438 047 096 146 196 245 295 345 394 443 448 453 458 463 468 473 478 483 488 493 498 547 596 645 694 743 792 841 890 503 552 601 650 699 748 797 846 895 507 557 606 655 704 753 802 851 900 512 562 611 660 709 758 807 856 905 517 567 616 665 714 763 812 861 910 522 571 621 670 719 768 817 866 915 527 576 626 675 724 773 822 871 919 532 581 630 680 729 778 827 876 924 537 586 635 685 734 783 832 880 929 542 591 640 689 738 787 836 885 934 939 944 949 954 959 963 968 973 978 983 988 95 036 085 134 182 231 279 328 37 € 993 041 090 139 i 187 236 ' 284 1 332 i 381 998 046 095 143 192 240 289 337 386 *002 051 100 148 197 245 294 342 390 *007 056 105 153 202 -250 299 347 395 *012 061 109 158 207 255 303 352 400 *017 066 114 163 211 260 308 357 405 *022 071 119 168 216 265 313 361 410 *027 075 124 173 221 270 318 366 415 *032 080 129 177 226 274 323 371 419 424 t 429 434 439 444 448 453 458 463 468 N. * L. 0 1 2 3 4 5 6 7 8 9 P. P. 490 LOGARITHMS . N. L. 0 1 2 3 4 5 6 7 8 9 P. P. soo 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 924 925 926 927 928 929 930 931 932 933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 950 & 424 429 434 439 444 448 453 458 463 468 5 1 0.5 2 1.0 3 1.5 4 2.0 5 2.5 6 3.0 7 3.5 8 4.0 9 4.5 4 1 0.4 2 0.8 3 1.2 4 1.6 5 2.0 6 2.4 7 2.8 8 3.2 | 9 3.6 472 521 569 617 665 713 761 809 856 477 525 574 622 670 718 766 813 861 482 530 578 626 674 722 770 818 866 487 535 583 631 679 727 775 823 871 492 540 588 636 684 732 780 828 875 497 545 593 641 689 737 785 832 880 501 550 598 646 694 742 789 837 885 506 554 602 650 698 746 794 842 890 511 559 607 655 703 751 799 847 895 516 564 612 660 708 756 804 852 899 904 909 914 918 923 928 933 938 942 947 952 999 96 047 095 142 190 237 284 332 957 *004 052 099 147 194 242 289 336 961 *009 057 104 152 199 246 294 341 966 *014 061 109 156 204 251 298 346 971 *019 066 114 161 209 256 303 350 976 *023 071 118 166 213 261 308 355 980 *028 076 123 171 218 265 313 360 985 *033 080 128 175 223 270 317 365 990 *038 085 133 180 227 275 322 369 995 *042 090 137 185 232 280 327 374 379 384 388 393 398 402 407 412 417 421 426 473 520 567 614 661 708 755 802 431 478 525 572 619 666 713 759 806 435 483 530 577 624 670 717 764 811 440 487 534 581 628 675 722 769 .816 445 492 539 586 633 680 727 774 820 450 497 544 591 638 685 731 778 825 454 501 548 595 642 689 736 783 830 459 506 553 600 647 694 741 788 834 464 511 558 605 652 699 745 792 839 468 515 562 609 656 703 750 797 844 848 853 858 862 867 872 876 881 886 890 895 942 988 97 035 081 128 174 220 267 900 946 993 039 086 132 179 225 271 904 951 997 044 090 137 183 230 276 909 956 *002 049 095 142 188 234 280 914 960 *007 053 100 146 192 239 285 918 965 *011 058 104 151 197 243 290 923 970 *016 063 109 155 202 248 294 928 974 *021 067 114 160 206 253 299 932 979 *025 072 118 165 211 257 304 937 984 *030 077 123 169 216 262 308 313 317 322 327 331 336 340 345 350 354 359 405 451 I 497 543 589 635 681 727 364 410 456 502 , 548 i 594 > 640 685 ' 731 368 414 460 506 552 598 644 690 736 373 419 465 511 557 603 649 695 740 377 424 470 516 562 607 653 699 745 382 428 474 520 566 612 658 704 749 387 433 479 525 571 617 663 708 754 391 437 483 529 575 621 667 713 759 396 442 488 534 580 626 672 717 763 400 447 493 539 585 630 676 722 768 772 \ 777 782 786 791 795 800 804 809 813 N. L.O 1 2 3 4 5 6 7 8 9 P. P. LOGARITHMS 491 1 L 0 1 2 3 4 5 6 7 8 9 P. P. 950 Y7 772 ' 777 782 786 791 795 800 804 809 813 5 1 0.5 2 1.0 3 1.5 4 2.0 5 2.5 6 3.0 7 3.5 8 4.0 9 4.5 4 1 0.4 2 0.8 3 1.2 4 1.6 5 2.0 6 2.4 7 2.8 8 3.2 9 3.6 951 952 953 954 955 956 957 958 959 960 961 962 963 964 965 966 967 968 969 970 971 972 973 974 975 976 977 978. 979 980 981 982 983 984 985 986 987 988 989 990 991 992 993 994 995 996 997 998 999 I00C 818 864 909 955 )8 000 046 091 137 182 823 868 914 959 005 050 096 141 186 827 873 918 964 009 055 100 146 191 832 877 923 968 014 059 105 150 195 836 882 928 973 019 064 109 155 200 841 886 932 978 023 068 114 159 204 845 891 937 982 028 073 118 164' 209 850 896 941 987 032 078 123 168 214 855 900 946 991 037 082 127 173 218 859 905 950 996 041 087 132 177 223 227 232 236 241 245 250 254 259 263 268 272 318 363 408 453 498 543 588 632 277 322 367 412 457 502 547 592 637 281 327 372 417 462 507 552 597 641 286 331 376 421 466 511 556 601 646 290 336 381 426 471 516 561 605 650 295 340 385 430 475 520 565 610 655 299 345 390 435 480 525 570 614 659 304 349 394 439 484 529 574 619 664 308 354 399 444 489 534 579 623 668 313 358 403 448 493 538 583 628 673 677 682 686 691 695 700 704 709 713 717 722 767 811 856 900 945 989 99 034 078 726 771 816 860 905 949 994 038 083 731 776 820 865 909 954 998 043 087 735 780 825 869 914 958 *003 047 092 740 784 829 874 918 963 *007 052 096 744 789 834 878 923 967 *012 056 100 749 793 838 883 927 972 *016 061 105 753 798 843 887 932 976 *021 065 109 758 802 847 892 936 981 *025 069 114 762 807 851 896 941 985 *029 074 118 123 127 131 136 140 145 149 154 158 162 167 211 255 300 344 388 432 476 52C 171 216 260 304 348 i 392 ! 436 i 480 1 524 176 220 264 308 352 396 441 484 528 180 224 269 313 357 401 445 489 533 185 229 273 317 361 405 449 493 537 189 233 277 322 366 410 454 498 542 193 238 282 326 370 414 458 502 546 198 242 286 330 374 4ia 463 506 550 202 247 291 335 379 423 467 511 555 207 251 295 339 383 427 471 515 559 56 4 t 568 572 577 581 585 590 594 599 603 607 651 69 1 73< 782 '82( 87( 91; 95' ? 612 [ 656 > 699 ) 743 1 787 3 830 ) 874 3 917 7 961 616 660 704 747 791 835 878 922 965 621 664 708 752 795 839 883 926 970 625 669 712 756 800 843 887 930 974 629 673 717 760 804 848 891 935 978 634 677 721 765 808 852 896 939 983 638 682 726 769 813 856 900 944 987 642 686 730 774 817 861 904 948 991 647 691 734 778 822 865 909 952 996 | 00 001 1 004 009 013 017 022 026 030 035 039 N. L.O 1 1 2 3 I 4 5 6 7 8 9 P. P. 492 LOGAixs m ^ nv TRIGONOMETRIC FUNCTIONS. 0 ° // ~ o 60 120 180 240 / L. Sin. 1 d. Cpl. S. Cpl. T. L. Tang.j d. c. . L. Cotg. L. Cos. 0 1 2 3 4 6.46373 6.76476 6.94085 7.06579 30103 17609 12494 9691 7918 6694 5800 5115 4576 4139 3779 3476 3218 2997 2802 2633 2483 2348 2227 2119 2021 1930 1848 1773 1704 1639 1579 1524 1472 1424 1379 1336 1297 1259 1223 1190 1158 1128 1100 1072 1046 1022 999 976 954 934 914 896 877 860 843 827 812 797 782 769 755 743 730 5.31443 5.31443 5.31443 5.31443 5.31443 5.31443 5.31443 5.31442 6.46373 6.76476 6.94085 7.06579 30103 17609 12494 9691 7918 6694 5800 5115 4576 4139 3779 3476 3219 2996 2803 2633 2482 2348 2228 2119 2020 1931 1848 1773 1704 1639 1579 1524 1473 1424 1379 1336 1297 1259 1223 1190 1159 1128 1100 1072 1047 1022 998 976 955 934 915 895 878 860 843 828 812 797 782 769 756 742 730 3.53627 3.23524 3.05915 2.93421 0.00000 0.00000 0.00000 0.00000 0.00000 60 59 58 57 56 300 360 420 480 540 5 6 7 8 9 7.16270 7.24188 7.30882 7.36682 7.41797 5.31443 5.31443 5.31443 5.31443 5.31443 5.31442 5.31442 5.31442 5.31442 5.31442 7.16270 7.24188 7.30882 7.36682 7.41797 2.83730 2.75812 2.69118 2.63318 2.58203 0.00000 0.00000 0.00000 0.00000 0.00000 55 54 53 52 51 600 660 720 780 840 10 11 12 13 14 7.46373 7.50512 7.54291 7.57767 7.60985 5.31443 5.31443 5.31443 5.31443 5.31443 5.31442 5.31442 5.31442 5.31442 5.31442 7.46373 7.50512 7.54291 7.57767 7.60986 2.53627 2.49488 2.45709 2.42233 2.39014 0.00000 0.00000 0.00000 0.00000 0.00000 50 49 48 47 46 900 960 1020 1080 1140 15 16 17 18 19 7.63982 7.66784 7.69417 7.71900 7.74248 5.31443 5.31443 5.31443 5.31443 5.31443 5.31442 5.31442 5.31442 5.31442 5.31442 7.63982 7.66785 7.69418 7.71900 7.74248 2.36018 2.33215 2.30582 2.28100 2.25752 0.00000 0.00000 9.99999 9.99999 9.99999 45 44 43 42 41 1200 1260 1320 1380 1440 20 21 22 23 24 7.76475 7.78594 7.80615 7.82545 7.84393 5.31443 5.31443 5.31443 5.31443 5.31443 5.31442 5.31442 5.31442 5.31442 5.31442 7.76476 7.78595 7.80615 7.82546 7.84394 2.23524 2.21405 2.19385 2.17454 2.15606 9.99999 9.99999 9.99999 9.99999 9.99999 40 39 38 37 36 1500 1560 1620 1680 1740 25 26 27 28 29 7.86166 7.87870 7.89509 7.91088 7.92612 5.31443 5.31443 5.31443 5.31443 5.31443 5.31442 5.31442 5.31442 5.31442 5.31441 7.86167 7.87871 7.89510 7.91089 7.92613 2.13833 2.12129 2.10490 2.08911 2.07387 9.99999 9.99999 9.99999 9.99999 9.99998 35 34 33 32 31 1800 1860 1920 1980 2040 30 31 32 33 34 7.94084 7.95508 7.96887 7.98223 7.99520 5.31443 5.31443 5.31443 5.31443 5.31443 5.31441 5.31441 5.31441 5.31441 5.31441 7.94086 7.95510 7.96889 7.98225 7.99522 2.05914 2.04490 2.03111 2.01775 2.00478 9.99998 9.99998 9.99998 9.99998 9.99998 30 29 28 27 26 2100 2160 2220 2280 2340 35 36 37 38 39 8.00779 8.02002 8.03192 8.04350 8.05478 5.31443 5.31443 5.31443 5.31443 5.31443 5.31441 5.31441 5.31441 5.31441 5.31441 8.00781 8.02004 8.03194 8.04353 8.05481 1.99219 1.97996 1.96806 1.95647 1.94519 9.99998 9.99998 9.99997 9.99997 9.99997 25 24 23 22 21 2400 2460 2520 2580 2640 40 41 42 43 44 8.06578 8.07650 8.08696 8.09718 8.10717 5.31443 5.31444 5.31444 5.31444 5.31444 5.31441 5.31440 5.31440 5.31440 5.31440 8.06581 8.07653 8.08700 8.09722 8.10720 1.93419 1.92347 1.91300 1.90278 1.89280 9.99997 9.99997 9.99997 9.99997 9.99996 20 19 18 17 16 2700 2760 2820 2880 2940 45 46 47 48 49 8.11693 8.12647 8.13581 8.14495 8.15391 5.31444 5.31444 5.31444 5.31444 5.31444 5.31440 5.31440 5.31440 5.31440 5.31440 8.11696 8.12651 8.13585 8.14500 8.15395 1.88304 1.87349 1.86415 1.85500 1.84605 9.99996 9.99996 9.99996 9.99996 9.99996 15 14 13 12 11 3000 3060 3120 3180 3240 50 51 52 53 54 8.16268 8.17128 8.17971 8.18798 8.19610 5.31444 5.31444 5.31444 5.31444 5.31444 5.31439 5.31439 5.31439 5.31439 5.31439 8.16273 8.17133 8.17976 8.18804 8.19616 1.83727 1.82867 1.82024 1.81196 1.80384 9.99995 9.99995 9.99995 9.99995 9.99995 10 9 8 7 6 3300 3360 3420 3480 3540 55 56 57 58 59 8.20407 8.21189 8.21958 8.22713 8.23456 5.31444 5.31444 5.31445 5.31445 5.31445 5.31439 5.31439 5.31439 5.31438 5.31438 8.20413 8.21195 8.21964 8.22720 8.23462 1.79587 1.78805 1.78036 1.77280 1.76538 9.99994 9.99994 9.99994 9.99994 9.99994 5 4 3 2 1 3600 60 8.24186 5.31445 5.31438 8.24192 1.75808 9.99993 0 L. Cos. 1 d. L. Cotg. d. c. L. Tang. L. Sin. / 89 ° 493 LOGARITHMS OF TRIGONOMETRIC FTT 1 v n / L. Sin. d. Cpl. S. Cpl. T. I j. Tang. d. c. L. Cotg. L. Cos. 3600 3660 3720 3780 3840 0 1 2 3 4 8.24186 8.24903 8.25609 8.26304 8.26988 717 706 695 684 5.31445 5.31445 5.31445 5.31445 5.31445 5.31438 5.31438 5.31438 5.31438 5.31437 8.24192 8.24910 8.25616 8.26312 8.26996 718 706 696 684 673 - 1.75808 ' 1.75090 1.74384 1.73688 1.73004 9.99993 9.99993 9.99993 9.99993 9.99992 60 59 58 57 56 55 54 53 52 51 3900 3960 4020 4080 4140 5 6 7 8 9 8.27661 8.28324 8.28977 8.29621 8.30255 673 663 653 644 634 624 616 608 599 590 583 575 568 560 553 547 539 533 526 520 514 508 502 496 491 485 480 474 470 464 459 455 450 445 441 436 433 427 424 419 5.31445 5.31445 5.31445 5.31445 5.31445 5.31437 5.31437 5.31437 5.31437 5.31437 8.27669 8.28332 8.28986 8.29629 8.30263 663 654 643 634 625 - 1.72331 1.71668 1.71014 1.70371 1.69737 9.99992 9.99992 9.99992 9.99992 9.99991 4200 4260 4320 4380 4440 10 11 12 13 14 8.30879 8,31495 8.32103 8.32702 8.33292 5.31446 5.31446 5.31446 5.31446 5.31446 5.31437 5.31436 5.31436 5.31436 5.31436 8.30888 8.31505 8.32112 8.32711 8.33302 617 607 599 591 584 - 1.69112 1.68495 1.67888 1.67289 1.66698 9.99991 9.99991 9.99990 9.99990 9.99990 50 49 48 47 46 4500 4560 4620 4680 4740 15 16 17 18 19 8.33875 8.34450 8.35018 8.35578 8.36131 5.31446 5.31446 5 31446 5.31446 5.31446 5.31436 5.31435 5.31435 5.31435 5.31435 8.33886 8.34461 8.35029 8.35590 8.36143 575 568 561 553 546 1.66114 1.65539 1.64971 1.64410 1.63857 9.99990 9.99989 9.99989 9.99989 9.99989 45 44 43 42 41 4800 4860 4920 4980 5040 20 21 22 23 24 8.36678 8.37217 8.37750 8.38276 8.38796 5.31446 5.31447 5.31447 5.31447 5.31447 5.31435 5.31434 5.31434 5.31434 5.31434 8.36689 8.37229 8.37762 8.38289 8.38809 540 533 527 520 514 1.63311 1.62771 1.62238 1.61711 1.61191 9.99988 9.99988 9.99988 9.99987 9.99987 40 39 38 37 36 5100 5160 5220 5280 5340 25 26 27 28 29 8.39310 8.39818 8.40320 8.40816 8.41307 5.31447 5.31447 5.31447 5.31447 5.31447 5.31434 5.31433 5.31433 5.31433 5.31433 8.39323 8.39832 8.40334 8.40830 8.41321 509 502 496 491 486 1.60677 1.60168 1.59666 1.59170 1.58679 9.99987 9.99986 9.99986 9.99986 9.99985 35 34 33 32 31 5400 5460 5520 5580 5640 30 31 32 33 34 8.41792 8.42272 8.42746 8.43216 8.43680 5.31447 5.31448 5.31448 5.31448 5.31448 5.31433 5.31432 5.31432 5.31432 5.31432 8.41807 8.42287 8.42762 8.43232 8.43696 480 475 470 464 460 1.58193 1.57713 1.57238 1.56768 1.56304 9.99985 9.99985 9.99984 9.99984 9.99984 30 29 28 27 26 5700 5760 5820 5880 5940 35 36 37 38 39 8.44139 8.44594 8.45044 8.45489 8.45930 5.31448 5.31448 5.31448 5.31448 5.31449 5.31431 5.31431 5.31431 5.31431 5.31431 8.44156 8.44611 8.45061 8.45507 8.45948 455 450 446 441 437 1.55844 1.55389 1.54939 1.54493 1.54052 9.99983 9.99983 9.99983 9.99982 9.99982 25 24 23 ‘ 22 21 6000 6060 6120 6180 6240 40 41 42 43 44 8.46366 8.46799 8.47226 8.47650 8.48069 5.31449 5.31449 5.31449 5.31449 5.31449 5.31430 5.31430 5.31430 5.31430 5.31429 8.46385 8.46817 8.47245 8.47669 8.48089 432 428 424 420 • 416 412 408 404 401 - 397 393 390 386 383 380 1.53615 1.53183 1.52755 1.52331 1.51911 9.99982 9.99981 9.99981 9.99981 9.99980 20 19 18 17 16 6300 6360 6420 6480 6540 45 46 47 48 49 8.48485 8.48896 8.49304 8.49708 8.50108 416 411 408 404 400 5.31449 5.31449 5.31450 5.31450 5.31450 5.31429 5.31429 5.31428 5.31428 5.31428 8.48505 8.48917 8.49325 8.49729 8.50130 1.51495 1.51083 1.50675 1.50271 1.49870 9.99980 9.99979 9.99979 9.99979 9.99978 15 14 13 12 11 6600 6660 6720 6780 6840 50 51 52 53 54 8.50504 8.50897 8.51287 8.51673 8.52055 - 396 393 390 386 382 5.31450 5.31450 5.31450 5.31450 5.31450 5.31428 5.31427 5.31427 5.31427 5.31427 8.50527 8.50920 8.51310 8.51696 : 8.52079 1.49473 1.49080 1.48690 1.48304 1.47921 9.99978 9.99977 9.99977 9.99977 9.99976 10 9 8 7 6 6900 6960 7020 7080 7140 55 56 57 58 59 8.52434 8.52810 8.53183 8.53552 8.53919 - 379 376 373 i 369 i 367 5.31451 5.31451 5.31451 5.31451 5.31451 5.31426 5.31426 5.31426 5.31425 5.31425 8.52459 8.52835 8.53208 ■ 8.53578 i 8.53945 376 373 370 367 363 1.47541 1.47165 1.46792 1.46422 1.46055 9.99976 9.99975 9.99975 9.99974 9.99974 5 4 3 2' 1 7200 60 8.54282 - 363 5.31451 5.31425 > 8.54308 1.45692 9.99974 0 L. Cos . d. L. Cots % d.c.lL. Tans L. Sin. 88 ° 4»4 mn A T! ITHMS OF TRIGONOMETRIC FUNCTIONS. e" u t L. Sin. d. Cpl. S. Cpl. T. L. Tang. d. c. L. Cotg. L. Cos. 7200 7260 7320 7380 7440 0 1 2 3 4 8.54282 8.54642 8.54999 8.55354 8.55705 360 357 355 351 349 346 343 341 337 336 332 330 328 325 323 320 318 316 313 311 309 307 305 302 301 298 296 294 293 290 288 287 284 283 281 279 277 276 274 272 270 269 267 266 263 263 260 259 258 256 254 253 252 250 249 247 246 244 243 242 5.31451 5.31451 5.31452 5.31452 5.31452 5.31425 5.31425 5.31424 5.31424 5.31424 8.54308 8.54669 8.55027 8.55382 8.55734 361 358 355 352 349 346 344 341 338 336 333 330 328 326 323 321 319 316 314 311 310 307 305 303 301 299 297 295 292 291 289 287 285 284 281 280 278 276 274 273 271 269 268 266 264 263 261 260 258 257 255 254 252 251 249 248 246 245 244 243 1.45692 1.45331 1.44973 1.44618 1.44266 9.99974 9.99973 9.99973 9.99972 9.99972 60 59 58 57 56 7500 7560 7620 7680 7740 5 6 7 8 9 8.56054 8.56400 8.56743 8.57084 8.57421 5.31452 5.31452 5.31452 5.31453 5.31453 5.31423 5.31423 5.31423 5.31422 5.31422 8.56083 8.56429 8.56773 8.57114 8.57452 1.43917 1.43571 1.43227 1.42886 1.42548 9.99971 9.99971 9.99970 9.99970 9.99969 55 54 53 52 51 7800 7860 7920 7980 8040 10 11 12 13 14 8.57757 8.58089 8.58419 8.58747 8.59072 5.31453 5.31453 5.31453 5.31453 5.31454 5.31422 5.31421 5.31421 5.31421 5.31421 8.57788 8.58121 8.58451 8.58779 8.59105 1.42212 1.41879 1.41549 1.41221 1.40895 9.99969 9.99968 9.99968 9.99967 9.99967 50 49 48 47 46 45 44 43 42 41 8100 8160 8220 8280 8340 15 16 17 18 19 8.59395 8.59715 8.60033 8.60349 8.60662 5.31454 5.31454 5.31454 5.31454 5.31454 5.31420 5.31420 5.31420 5.31419 5.31419 8.59428 8.59749 8.60068 8.60384 8.60698 1.40572 1.40251 1.39932 1.39616 1.39302 9.99967 9.99966 9.99966 9.99965 9.99964 8400 8460 8520 8580 8640 20 21 22 23 24 8.60973 8.61282 8.61589 8.61894 8.62196 5.31455 5.31455 5.31455 5.31455 5.31455 5.31418 5.31418 5.31418 5.31417 5.31417 8.61009 8.61319 8.61626 8.61931 8.62234 1.38991 1.38681 1.38374 1.38069 1.37766 9.99964 9.99963 9.99963 9.99962 9.99962 40 39 38 37 36 8700 8760 8820 8880 8940 25 26 27 28 29 8.62497 8.62795 8.63091 8.63385 8.63678 5.31455 5.31456 5.31456 5.31456 5.31456 5.31417 5.31416 5.31416 5.31416 5.31415 8.62535 8.62834 8.63131 8.63426 8.63718 1.37465 1.37166 1.36869 1.36574 1.36282 9.99961 9.99961 9.99960 9.99960 9.99959 35 34 33 32 31 9000 9060 9120 9180 9240 30 31 32 33 34 8.63968 8.64256 8.64543 8.64827 8.65110 5.31456 5.31456 5.31457 5.31457 5.31457 5.31415 5.31415 5.31414 5.31414 5.31413 8.64009 8.64298 8.64585 8.64870 8.65154 1.35991 1.35702 1.35415 1.35130 1.34846 9.99959 9.99958 9.99958 9.99957 9.99956 30 29 28 27 26 9300 9360 9420 9480 9540 35 36 37 38 39 8.65391 8.65670 8.65947 8.66223 8.66497 5.31457 5.31457 5.31458 5.31458 5.31458 5.31413 5.31413 5.31412 5.31412 5.31412 8.65435 8.65715 8.65993 8.66269 8.66543 1.34565 1.34285 1.34007 1.33731 1.33457 9.99956 9.99955 9.99955 9.99954 9.99954 25 24 23 22 21 9600 9660 9720 9780 9840 40 41 42 43 44 8.66769 8.67039 8.67308 8.67575 8.67841 5.31458 5.31458 5.31459 5.31459 5.31459 5.31411 5.31411 5.31410 5.31410 5.31410 8.66816 8.67087 8.67356 8.67624 8.67890 1.33184 1.32913 1.32644 1.32376 1.32110 9.99953 9.99952 9.99952 9.99951 9.99951 20 19 18 17 16 9900 9960 10020 10080 10140 45 46 47 48 49 8.68104 8.68367 8.68627 8.68886 8.69144 5.31459 5.31459 5.31460 5.31460 5.31460 5.31409 5.31409 5.31408 5.31408 5.31408 8.68154 8.68417 8.68678 8.68938 8.69196 1.31846 1.31583 1.31322 1.31062 1.30804 9.99950 9.99949 9.99949 9.99948 9.99948 15 14 13 12 11 10200 10260 10320 10380 10440 50 51 52 53 54 8.69400 8.69654 8.69907 8.70159 8.70409 5.31460 5.31460 5.31461 5.31461 5.31461 5.31407 5.31407 5.31406 5.31406 5.31405 8.69453 8.69708 8.69962 8.70214 8.70465 1.30547 1.30292 1.30038 1.29786 1.29535 9.99947 9.99946 9.99946 9.99945 9.99944 10 9 8 7 6 10500 10560 . 10620 10680 10740 55 56 57 58 59 8.70658 8.70905 8.71151 8.71395 8.71638 5.31461 5.31461 5.31462 5.31462 5.31462 5.31405 5.31405 5.31404 5.31404 5.31403 8.70714 8.70962 8.71208 8.71453 8.71697 1.29286 1.29038 1.28792 1.28547 1.28303 9.99944 9.99943 9.99942 9.99942 9.99941 5 4 3 2 1 10800 60 8.71880 5.31462 5.31403 8.71940 1.28060 9.99940 0 L. Cos. d. L. Cotg. d. c. L. Tang. L. Sin. / 87 ° LOGARITHMS OF TRIGONOMETRIC FUNCTIONS. 495 ' ] L. Sin. ( 0 1 3.71880 0 1 * 3.72120 l 2 1 3.72359 i 3 1 3.72597 i 4 3.72834 % 5 ! 8.73069 0 6 : 8.73303 i 7 8.73535 i 8 8.73767 i 9 8.73997 % 10 8.74226 11 8.74454 i 12 8.74680 i 13 8.74906 f 14 8.75130 i 15 8.75353 J 16 8.75575 i 17 8.75795 i 18 8.76015 i 19 8.76234 ; 20 8.76451 ; 21 8.76667 ; 22 8.76883 ; 23 8.77097 ; 24 8.77310 ; 25 8.77522 ; 26 8.77733 27 8.77943 28 8.78152 29 8.78360 30 8.78568 31 8.78774 32 8.78979 33 8.79183 34 8.79386 35 8.79588 36 8.79789 37 8.79990 38 8.80189 39 8.80388 40 8.80585 41 8.80782 42 8.80978 43 8.81173 44 8.81367 45 ' 8.81560 46 8.81752 47 8.81944 48 8.82134 49 8.82324 50 8.82513 51 8.82701 52 8.82888 53 8.83075 54 8.83261 55 8.83446 56 8.83630 57 8.83813 58 8.83996 59 8.84177 60 8.84358 L. Cos. 229 228 226 226 224 223 222 220 220 219 217 216 216 214 213 212 211 210 209 208 L.Tang. d. 8.71940 8.72181 £ 8.72420 £ 8.72659 % 8.72896 £ 8.73132 % 8.73366 % 8.73600 % 8.73832 2- 8.74063 % 8.74292 o ; 8.74521 2 8.74748 2 8.74974 * 8.75199 2 8.75423 0 8.75645 2 8.75867 2 8.76087 2 8.76306 2 8.76525 . 8.76742 i 8.76958 i 8.77173 i 8.77387 i 8.77600 ' 8.77811 ; 8.78022 * ' 8.78232 ; ; 8.78441 ; ! 8.78649 ; » 8.78855 ; | 8.79061 ; 8.79266 ; 5 8.79470 ' 8.79673 \ 8.79875 { 8.80076 l 8.80277 ^ 8.80476 i 8.80674 l 8.80872 ° 8.81068 5 8.81264 i 8.81459 t 8.81653 2 8.81846 2 8.82038 5 8.82230 5> 8.82420 7 8.82610 » 8.82799 4 8.82987 7 8.83175 8.83361 , 8.83547 $4 8.83732 3 8.83916 g 8.84100 *1 8.84282 31 8.84464 d. L. Cotg. 201 201 199 198 198 196 196 195 194 193 192 192 190 190 189 188 188 186 186 185 184 184 182 182 Ic j. Cotg. ] L. Cos. 1.28060 1 3.99940 ( 50 1.27819 1 3.99940 59 1.27580 ! 3.99939 58 1.27341 1 3.99938 57 1.27104 ' 3.99938 56 1.26868 1 9.99937 55 1.26634 9.99936 54 1.26400 9.99936 53 1.26168 9.99935 52 1.25937 9.99934 51 1.25708 9.99934 50 1.25479 9.99933 49 1.25252 9.99932 48 1.25026 9.99932 47 1.24801 9.99931 46 1.24577 9.99930 45 1.24355 9.99929 44 1.24133 9.99929 43 1.23913 9.99928 42 1.23694 9.99927 41 1.23475 9.99926 40 1.23258 9.99926 39 1.23042 9.99925 38 1.22827 9.99924 37 1.22613 9.99923 36 1.22400 9.99923 35 1.22189 9.99922 34 1.21978 9.99921 33 1.21768 9.99920 32 1.21559 9.99920 31 1.21351 9.99919 30 1.21145 9.99918 29 1.20939 9.99917 28 1.20734 9.99917 27 1.20530 9.99916 26 1.20327 9.99915 25 1.20125 9.99914 24 1.19924 9.99913 23 1.19723 9.99913 22 1.19524 9.99912 21 1.19326 9.99911 20 1.19128 9.99910 19 1.18932 9.99909 18 1.18736 9.99909 17 1.18541 9.99908 16 1.18347 9.99907 15 1.18154 9.99906 14 1.17962 9.99905 13 1.17770 9.99904 12 1.17580 9.99904 11 1.17390 9.99903 10 1.17201 9.99902 : 9 1.17013 , 9.99901 8 1.16825 i 9.99900 i 7 1.16639 i 9.99899 i 6 1.16453 i 9.99898 i 5 1.1626? ; 9.99898 1 4 1.16084 [ 9.99897 r 3 1.1590C > 9.99896 i 2 ; 1.1571? * 9.9989£ ► 1 1 1.1553* J 9.99894 L 0 5. L.Tang r. L. Sin / P. P. 238 23.8 27.8 31.7 35.7 39.7 79.3 119.0 158.7 198.3 234 23.4 27.3 31.2 35.1 39.0 78.0 117.0 156.0 195.0 229 22.9 26.7 30.5 34.4 38.2 76.3 114.5 152.7 190.8 225 220 216 22.5 22.0 21.6 26.3 25.7 25.2 30.0 29.3 28.8 33.8 33.0 32.4 37.5 36.7 36.0 75.0 73.3 72.0 112.5 110.0 108.0 150.0 146.7 144.0 187.5 183.3 180.0 212 208 204 21.2 20.8 20.4 24.7 24.3 23.8 28.3 27.7 27.2 31.8 31.2 30.6 35.3 34.7 34.0 70.7 69.3 68.0 106.0 104.0 102.0 141.3 138.7 136.0 176.7 173.3 170.0 201 197 193 20.1 23.5 26.8 30.2 33.5 67.0 100.5 134.0 167.5 189 18.9 22.1 25.2 28.4 31.5 63.0 94.5 126.0 l 157.5 19.7 23.0 26.3 29.6 32.8 65.7 98.5 131.3 164.2 185 18.5 21.6 24.7 27.8 30.8 61.7 92.5 123.3 154.2 4 3 2 6 0.4 0.3 0.2 7 0.5 0.4 0.2 8 0.5 0.4 0.3 9 0.6 0.5 0.3 10 0.7 0.5 0.3 20 1.3 1.0 0.7 30 2.0 1.5 1.0 40 2.7 2.0 1.3 50 3.3 2.5 1.7 19.3 22.5 25.7 29.0 32.2 64.3 96.5 128.7 160.8 181 18.1 21.1 24.1 27.2 30.2 60.3 90.5 120.7 150.8 0.1 0.1 0.1 0.2 0.2 0.3 0.5 0.7 0.8 P. P. 86 ° LOGARITHMS OF TRIGONOMETRIC FUNCTIONS. 4 ° / L. Sin. d. L.Tang. d. c. L. Cotg. L. Cos. P. P. 0 1 2 3 4 8.84358 8.84539 8.84718 8.84897 8.85075 181 179 179 178 177 177 176 175 175 173 173 173 171 171 171 169 169 169 167 168 166 166 165 164 164 163 163 162 162 160 161 159 159 159 158 157 157 156 155 155 155 154 153 153 152 152 151 151 150 150 149 149 148 147 147 147 146 146 145 145 8.84464 8.84646 8.84826 8.85006 8.85185 182 180 180 179 178 177 177 176 176 174 174 174 172 172 171 171 170 169 169 168 167 167 166 165 165 165 163 163 163 161 162 160 160 160 159 158 158 157 157 156 155 155 155 153 154 153 152 152 151 151 150 150 149 148 149 147 147 147 146 146 1.15536 1.15354 1.15174 1.14994 1.14815 9.99894 9.99893 9.99892 9.99891 9.99891 60 59 58 57 56 181 6 18.1 7 21.1 8 24.1 9 27.2 10 30.2 20 60.3 30 90.5 40 120.7 50 150.8 175 6 17.5 7 20.4 8 23.3 9 26.3 10 29.2 20 58.3 30 87.5 40 116.7 50 145.8 168 6 16.8 7 19.6 8 22.4 9 25.2 10 28.0 20 56.0 30 84.0 40 112.0 50 140.0 162 6 16.2 7 18.9 8 21.6 9 24.3 10 27.0 20 54.0 30 81.0 40 108.0 50 135.0 155 6 15.5 7 18.1 8 20.7 9 23.3 10 25.8 20 51.7 30 77.5 40 103.3 50 129.2 149 6 14.9 7 17.4 8 19.9 9 22.4 10 24.8 20 49.7 30 74.5 40 99.3 50 124.2 179 17.9 20.9 23.9 26.9 29.8 59.7 89.5 119.3 149.2 173 17.3 20.2 23.1 26.0 28.8 57.7 86.5 115.3 144.2 166 16.6 19.4 22.1 24.9 27.7 55.3 83.0 110.7 138.3 159 15.9 18.6 21.2 23.9 26.5 53.0 79.5 106.0 132.5 153 15.3 17.9 20.4 23.0 25.5 51.0 76.5 102.0 127.5 147 14.7 17.2 19.6 22.1 24.5 49.0 73.5 98.0 122.5 177 17.7 20.7 23.6 26.6 29.5 59.0 88.5 118.0 147.5 171 17.1 20.0 22.8 25.7 28.5 57.0 85.5 114.0 142.5 164 16.4 19.1 21.9 24.6 27.3 54.7 82.0 109.3 136.7 157 15.7 18.3 20.9 23.6 26.2 52.3 78.5 104.7 130.8 151 15.1 17.6 20.1 22.7 25.2 50.3 75.5 100.7 125.8 1 0.1 0.1 0.1 0.2 0.2 0.3 0.5 0.7 0.8 5 6 7 8 9 8.85252 8.85429 8.85605 8.85780 8.85955 8.85363 8.85540 8.85717 8.85893 8.86069 1.14637 1.14460 1.14283 1.14107 1.13931 9.99890 9.99889 9.99888 9.99887 9.99886 55 54 53 52 51 10 11 12 13 14 8.86128 8.86301 8.86474 8.86645 8.86816 8.86243 8.86417 8.86591 8.86763 8.86935 1.13757 1.13583 1.13409 1.13237 1.13065 9.99885 9.99884 9.99883 9.99882 9.99881 50 49 48 47 46 15 16 17 18 19 8.86987 8.87156 8.87325 8.87494 8.87661 8.87106 8.87277 8.87447 8.87616 8.87785 1.12894 1.12723 1.12553 1.12384 1.12215 9.99880 9.99879 9 99879 9.99878 9.99877 45 44 43 42 41 20 21 22 23 24 8.87829 8.87995 8.88161 8.88326 8.88490 8.87953 8.88120 8.88287 8.88453 8.88618 1.12047 1.11880 1.11713 1.11547 1.11382 9.99876 9.99875 9.99874 9.99873 9.99872 40 39 38 37 36 25 26 27 28 29 8.88654 8.88817 8.88980 8.89142 8.89304 8.88783 8.88948 8.89111 8.89274 8.89437 1.11217 1.11052 1.10889 1.10726 1.10563 9.99871 9.99870 9.99869 9.99868 9.99867 35 34 33 32 31 30 31 32 33 34 8.89464 8.89625 8.89784 8.89943 8.90102 8.89598 8.89760 8.89920 8.90080 8.90240 1.10402 1.10240 1.10080 1.09920 1.09760 9.99866 9.99865 9.99864 9.99863 9.99862 30 29 28 27 26 35 36 37 38 39 8.90260 8.90417 8.90574 8.90730 8.90885 8.90399 8.90557 8.90715 8.90872 8.91029 1.09601 1.09443 1.09285 1.09128 1.08971 9.99861 9.99860 9.99859 9.99858 9.99857 25 24 23 22 21 40 41 42 43 44 8.91040 8.91195 8.91349 8.91502 8.91655 8.91185 8.91340 8.91495 8.91650 8.91803 1.08815 1.08660 1.08505 1.08350 1.08197 9.99856 9.99855 9.99854 9.99853 9.99852 20 19 18 17 16 45 46 47 48 49 8.91807 8.91959 8.92110 8.92261 8.92411 8.91957 8.92110 8.92262 8.92414 8.92565 1.08043 1.07890 1.07738 1.07586 1.07435 9.99851 9.99850 9.99848 9.99847 9.99846 15 14 13 12 11 50 51 52 53 54 8.92561 8.92710 8.92859 8.93007 8.93154 8.92716 8.92866 8.93016 8.93165 8.93313 1.07284 1.07134 1.06984 1.06835 1.06687 9.99845 9.99844 9.99843 9.99842 9.99841 10 9 8 7 6 55 56 57 58 59 8.93301 8.93448 8.93594 8.93740 8.93885 8.93462 3.93609 8.93756 8.93903 8.94049 1.06538 1.06391 1.06244 1.06097 1.05951 9.99840 9.99839 9.99838 9.99837 9.99836 5 4 3 2 1 60 8.94030 8.94195 1.05805 9.99834 0 L. Cos. d. L. Cotg. d. c. L.Tang. L. Sin. / P. P. 85 ° 497 Logarithms of trigonometric functions. 5 ° . ) L. Sin. d. I j.Tang. d. c. 1 Cotg. L. Cos. P. P. 0 1 2 3 4 8794030 “ 8.94174 8.94317 8.94461 8.94603 144 143 144 142 8.94195 8.94340 8.94485 8.94630 8.94773 145 145 145 143 I'M 1.05805 1.05660 1.05515 1.05370 1.05227 9.99834 9.99833 9.99832 9.99831 9.99830 60 59 58 57 56 6 7 8 9 145 14.5 16.9 19.3 21.8 143 14.3 16.7 19.1 21.5 141 14.1 16.5 18.8 21.2 23.5 47.0 70.5 94.0 117.5 5 6 7 8 9 8.94746 8.94887 8.95029 8.95170 8.95310 143 141 142 141 140 140 139 139 139 138 138 137 137 136 136 136 135 135 134 134 133 133 133 132 132 131 131 131 130 130 129 129 129 128 128 128 127 127 126 126 8.94917 8.95060 8.95202 8.95344 8.95486 143 142 142 142 i/ii 1.05083 1.04940 1.04798 1.04656 1.04514 9.99829 9.99828 9.99827 9.99825 9.99824 55 54 53 52 51 10 20 30 40 50 24.2 48.3- 72.5 96.7 120.8 23.8 47.7 71.5 95.3 119.2 10 11 12 13 14 8.95450 8.95589 8.95728 8.95867 8.96005 8.95627 8.95767 8.95908 8.96047 8.96187 140 141 139 140 138 139 138 137 138 1.04373 1.04233 1.04092 1.03953 1.03813 9.99823 9.99822 9.99821 9.99820 9.99819 50 49 48 47 46 6 7 8 9 139 13.9 16.2 18.5 20.9 138 13.8 16.1 18.4 20.7 136 13.6 15.9 18.1 20.4 15 16 17 18 19 8.96143 8.96280 8.96417 8.96553 8.96689 8.96325 8.96464 8.96602 8.96739 8.96877 1.03675 1.03536 1.03398 1.03261 1.03123 9.99817 9.99816 9.99815 9.99814 9.99813 45 44 43 42 41 10 20 30 40 50 23.2 46.3 69.5 92.7 115.8 23.0 46.0 69.0 92.0 115.0 22.7 45.3 68.0 90.7 113.3 20 21 22 23 24 8.96825 8.96960 8.97095 8.97229 8.97363 8.97013 8.97150 8.97285 8.97421 8.97556 137 135 136 135 1.02987 1.02850 1.02715 1.02579 1.02444 9.99812 9.99810 9.99809 9.99808 9.99807 40 39 38 37 36 6 7 8 9 135 13.5 15.8 18.0 20.3 133 13.3 15.5 17.7 20.0 131 13.1 15.3 17.5 19.7 25 26 27 28 29 8.97496 8.97629 8.97762 8.97894 8.98026 8.97691 8.97825 8.97959 8.98092 8.98225 134 134 133 133 133 1.02309 1.02175 1.02041 1.01908 1.01775 9.99806 9.99804 9.99803 9.99802 9.99801 35 34 33 32 31 10 20 30 40 50 22.5 45.0 67.5 90.0 112.5 22.2 44.3 66.5 88.7 110.8 21.8 43.7 65.5 87.3 109.2 30 31 32 33 34 8.98157 8.98288 8.98419 8.98549 8.98679 8.98358 8.98490 8.98622 8.98753 8.98884 132 132 131 131 131 130 130 130 129 198 1.01642 1.01510 1.01378 1.01247 1.01116 9.99800 9.99798 9.99797 9.99796 9.99795 30 29 28 27 26 6 7 8 9 129 12.9 15.1 17.2 19.4 128 12.8 14.9 17.1 19.2 126 12.6 14.7 16.8 18.9 35 36 37 38 39 8.98808 8.98937 8.99066 8.99194 8.99322 8.99015 8.99145 8.99275 8.99405 8.99534 1.00985 1.00855 1.00725 1.00595 1.00466 9.99793 9.99792 9.99791 9.99790 9.99788 25 24 23 22 21 10 20 30 40 50 21.5 43;0 64.5 86.0 107,5 21.3 42.7 64.0 85.3 106.7 21.0 42.0 63.0 84.0 105.0 40 41 42 43 44 8.99450 8.99577 8.99704 8.99830 8.99956 8.99662 8.99791 8.99919 9.00046 9.00174 129 128 127 128 127 126 126 126 126 196 1.00338 1.00209 1.00081 0.99954 0.99826 9.99787 9.99786 9.99785 9.99783 9.99782 20 19 18 17 16 6 7 8 q 125 12.5 14.6 16.7 1ft 8 123 12.3 14.4 16.4 18.5 20.5 41.0 61.5 82.0 102.5 122 12.2 14.2 16.3 18.3 45 46 47 48 49 9.00082 9.00207 9.00332 9.00456 9.00581 126 125 125 124 125 9.00301 9.00427 9.00553 9.00679 9.00805 0.99699 0.99573 0.99447 0.99321 0.99195 9.99781 9.99780 9.99778 9.99777 9.99776 15 14 13 12 11 10 20 30 40 50 20.8 41.7 62.5 83.3 104.2 20.3 40.7 61.0 81.3 101.7 50 51 52 53 54 9.00704 9.00828 9.00951 9.01074 9.01196 - 123 124 123 123 | 122 9.00930 9.01055 9.01179 9.01303 9.01427 125 124 124 124 1 92 0.99070 0.98945 0.98821 0.98697 0.98573 9.99775 9.99773 9.99772 9.99771 9.99769 to 9 8 - 7 6 6 7 8 121 12.1 14.1 16.1 18.2 20.2 40.3 60.5 80.7 100.8 120 12.0 14.0 16.0 18 0 1 0.1 0.1 0.1 0.2 55 56 57 58 59 9.01318 9.01440 9.01561 9.01682 9.01802 - 122 1 m ► 121 ; 121 9.01550 9.01673 9.01796 9.01918 9.0204C ' 123 ; 123 122 122 122 0.98450 0.98327 0.98204 0.98082 0.97960 9.99768 9.99767 9.99765 9.99764 i 9.99763 5 4 3 2 1 V 10 20 30 40 50 iO.v 20.0 40.0 60.0 80.0 100.0 0.2 0.3 0.5 0.7 0.8 60 9.01922 - 120 9.0216S 0.97838 1 9.99761 0 L. Cos . d. L. Cots r. d. c *. L.Tang ; L. Sin. / P. P. 84 ° 498 LOGARITHMS OF TRIGONOMETRIC FUNCTIONS. 6 ° / L. Sin. d. L.Tang. d. c. L. Cotg. L. Cos. P. P. 0 1 2 3 4 9.01923 9.02043 9.02163 9.02283 9.02402 120 120 120 119 118 119 118 117 118 117 117 116 116 116 116 115 115 114 115 113 114 114 113 112 113 112 112 112 111 111 111 110 110 110 110 109 109 109 108 109 108 107 108 107 107 106 107 106 105 106 105 105 105 105 104 104 104 103 103 103 9.02162 9.02283 9.02404 9.02525 9.02645 121 121 121 120 121 119 120 119 118 119 118 118 117 118 116 117 116 116 116 115 115 115 115 114 114 113 114 113 112 113 112 112 112 111 111 111 110 111 110 109 110 109 109 108 109 108 108 107 108 107 106 107 106 106 106 106 105 105 105 104 0.97838 0.97717 0.97596 0.97475 0.97355 9.99761 9.99760 9.99759 9.99757 9.99756 60 59 58 57 56 12! 6 12.1 7 14.1 8 16.1 9 ' 18.2 10 20.2 20 40.3 3C 60.5 40 80.7 50 100.8 120 12.0 14.0 16.0 18.0 20.0 40.0 60.0 80.0 100.0 117 11.7 13.7 15.6 17.6 19.5 39.0 58.5 78.0 97.5 114 11.4 13.3 15.2 17.1 19.0 38.0 57.0 76.0 95.0 II! 11.1 13.0 14.8 16.7 18.5 37.0 55.5 74.0 92.5 108 10.8 12.6 14.4 16.2 18.0 36.0 54.0 72.0 90.0 105 10.5 12.3 14.0 15.8 17.5 35.0 52.5 70.0 87.5 119 11.9 13.9 15.9 17.9 19.8 39.7 59.5 79.3 99.2 116 11.6 13.5 15.5 17.4 19.3 38.7 58.0 77.3 96.7 113 11.3 13.2 15.1 17.0 18.8 37.7 56.5 75.3 94.2 110 11.0 12.8 14.7 16.5 18.3 36.7 55.0 73.3 91.7 107 10.7 12.5 14.3 16.1 17.8 35.7 53.5 71.3 89.2 IQ4 10.4 12.1 13.9 15.6 17.3 34.7 52.0 69.3 86.7 5 6 7 8 9 9.02520 9.02639 9.02757 9.02874 9.02992 9.02766 9.02885 9.03005 9.03124 9.03242 0.97234 0.97115 0.96995 0.96876 0.96758 9.99755 9.99753 9.99752 9.99751 9.99749 55 54 53 52 51 10 11 12 13 14 9.03109 9.03226 9.03342 9.03458 9.03574 9.03361 9.03479 9.03597 9.03714 9.03832 0.96639 0.96521 0.96403 0.96286 0.96168 9.99748 9.99747 9.99745 9.99744 9.99742 60 49 48 47 46 6 7 8 9 10 20 30 40 1 50 6 7 8 9 10 20 30 40 50 6 7 8 9 10 20 30 40 50 6 7 8 9 10 20 30 40 50 6 7 8 9 10 20 30 40 50 Ii8 11.8 13.8 15.7 17.7 19.7 39.3 59.0 78.7 98.3 115 11.5 13.4 15.3 17.3 19.2 38.3 57.5 76.7 95.8 112 11.2 13.1 14.9 16.8 18.7 37.3 56.0 74.7 93.3 <09 10.9 12.7 14.5 16.4 18.2 36.3 54.5 72.7 90.8 106 10.6 12.4 14.1 15.9 17.7 35.3 53.0 70.7 88.3 15 16 17 18 19 9.03690 9.03805 9.03920 9.04034 9.04149 9.03948 9.04065 9.04181 9.04297 9.04413 0.96052 0.95935 0.95819 0.95703 0.95587 9.99741 9.99740 9.99738 9.99737 9.99736 45 44 43 42 41 20 21 22 23 24 9.04262 9.04376 9.04490 9.04603 9.04715 9.04528 9.04643 9.04758 9.04873 9.04987 0.95472 0.95357 0.95242 0.95127 0.95013 9.99734 9.99733 9.99731 9.99730 9.99728 40 39 38 37 36 25 26 27 28 29 9.04828 9.04940 9.05052 9.05164 9.05275 9.05101 9.05214 9.05328 9.05441 9.05553 0.94899 0.94786 0.94672 0.94559 0.94447 9.99727 9.99726 9.99724 9.99723 9.99721 35 34 33 32 31 30 31 32 33 34 9.05386 9.05497 9.05607 9.05717 9.05827 9.05666 9.05778 9.05890 9.06002 9.06113 0.94334 0.94222 0.94110 0.93998 0.93887 9.99720 9.99718 9.99717 9.99716 9.99714 30 29 28 27 26 35 36 37 38 39 9.05937 9.06046 9.06155 9.06264 9.06372 9.06224 9.06335 9.06445 9.06556 9.06666 0.93776 0.93665 0.93555 0.93444 0.93334 9.99713 9.99711 9.99710 9.99708 9.99707 25 24 23 22 21 40 41 42 43 44 9.06481 9.06589 9.06696 9.06804 9.06911 9.06775 9.06885 9.06994 9.07103 9.07211 0.93225 0.93115 0.93006 0.92897 0.92789 9.99705 9.99704 9.99702 9.99701 9.99699 20 15 18 17 16 45 46 47 48 49 9.07018 9.07124 9.07231 9.07337 9.07442 9.07320 9.07428 9.07536 9.07643 9.07751 0.92680 0.92572 0.92464 0,92357 0.92249 9.99698 9.99696 9.99695 9.99693 9.99692 15 14 13 12 11 50 51 52 53 54 9.07548 9.07653 9.07758 9.07863 9.07968 9.07858 9.07964 9.08071 9.08177 9.08283 0.92142 0.92036 0.91929 0.91823 0.91717 9.99690 9.99689 9.99687 9.99686 9.99684 to 9 8 7 6 55 56 57 58 59 9.08072 9.08176 9.08280 9.08383 9.08486 9.08389 9.08495 9.08600 9.08705 9.08810 0.91611 0.91505 0.91400 0.91295 0.91190 9.99683 9.99681 9.99680 9.99678 9.99677 5 4 3 2 1 60 9.08589 9.08914 0.91086 9.99675 0 L. Cos. d. L. Cotg. d. c. L.Tang. L. Sin. / P. P. 83 ° LOGARITHMS OF TRIGONOMETRIC FUNCTIONS . 7 ° 499 ' ] L Sin. c 0 * >.08589 1 * >.08692 { 2 * >.08795 | 3 t >.08897 ]) 4 < >.08999 l 5 ! >.09101 6 ! >.09202 }) 7 1 >.09304 1 8 ! >.09405 j 9 1 9.09506 * 10 1 9.09606 , 11 1 9.09707 } 12 9.09807 } 13 9.09907 1 14 9.10006 15 9.10106 16 9.10205 17 9.10304 18 9.10402 19 9.10501 20 9.10599 21 9.10697 22 9.10795 23 9.10893 24 9.10990 25 9.11087 26 9.11184 27 9.11281 28 9.11377 29 9.11474 30 9.11570 31 9.11666 32 9.11761 33 9.11857 34 9.11952 35 9.12047 36 9.12142 37 9.12236 38 9.12331 39 9.12425 40 9.12519 41 9.12612 42 9.12706 43 9.12799 44 9.12892 45 9.12985 46 9.13078 47 9.13171 48 9.13263 49 9.13355 50 9.13447 51 9.13539 52 9.13630 53 9.13722 54 9.13813 55 9.13904 56 9.13994 57 9.14085 58 9.14175 59 9.14266 60 9.14356 L. Cos. d. L.Tang. 9.08914 9.09019 9.09123 9.09227 9.09330 9.09434 9.09537 9.09640 9.09742 9.09845 99 00 99 99 98 99 98 98 98 98 97 97 97 97 96 97 96 96 95 96 95 95 95 94 95 94 94 93 94 93 93 93 93 93 92 92 92 92 91 92 91 91 90 91 90 91 90 9.09947 9.10049 9.10150 9.10252 9.10353 9.10454 9.10555 9.10656 9.10756 9.10856 9.10956 9.11056 9.11155 9.11254 9.11353 9.11452 9.11551 9.11649 9.11747 9.11845 9.11943 9.12040 9.12138 9.12235 9.12332 105 104 104 103 104 103 103 102 103 102 102 101 102 101 101 101 101 100 100 100 100 99 99 9.12428 9.12525 9.12621 9.12717 9.12813 9.12909 9.13004 9.13099 9.13194 9.13289 9.13384 9.13478 9.13573 9.13667 9.13761 9.13854 9.13948 9.14041 9.14134 9.14227 9.14320 9.14412 9.14504 9.14597 9.14688 99 99 99 98 98 98 98 97 98 97 97 96 97 96 96 96 96 95 95 95 95 95 94 95 94 94 9.14780 d. L. Cotg L. Cotg. L. Cos. 0.91086 9.99675 f >0 0.90981 9.99674 J 59 0.90877 9.99672 J 58 0.90773 9.99670 ; 57 0.90670 9.99669 56 0.90566 9.99667 55 0.90463 9.99666 54 0.90360 9.99664 53 0.90258 9.99663 52 0.90155 9.99661 51 0.90053 9.99659 ! 50 0.89951 9.99658 49 0.89850 9.99656 48 0.89748 9.99655 47 0.89647 9.99653 46 0.89546 9.99651 45 0.89445 9.99650 44 0.89344 9.99648 43 0.89244 9.99647 42 0.89144 9.99645 41 0.89044 9.99643 40 0.88944 9.99642 39 0.88845 9.99640 38 0.88746 9.99638 37 0.88647 9.99637 36 0.88548 9.99635 35 0.88449 9.99633 34 0.88351 9.99632 33 0.88253 9.99630 32 0.88155 9.99629 31 0.88057 9.99627 30 0.87960 9.99625 29 0.87862 9.99624 28 0.87765 9.99622 27 0.87668 9.99620 26 0.87572 9.99618 25 0.87475 9.99617 24 0.87379 9.99615 23 0.87283 9.99613 22 0.87187 9.99612 21 0.87091 9.99610 20 0.86996 9.99608 19 0.86901 9.99607 18 0.86806 9.99605 17 0.86711 9.99603 16 0.86616 9.99601 15 0.86522 9.99600 14 0.86427 9.99598 13 0.86333 , 9.99596 12 j 0.86239 i 9.99595 11 ’ 0.86146 1 9.99593 10 : 0.86052 5 9.99591 9 I 0.85952 ) 9.99589 8 » 0.8586( } 9.99588 7 5 0.8577; 5 9.99586 6 ' 0.8568( ) 9.99584 5 \ 0.85585 3 9.99582 1 4 2 0.85491 5 9.99581 3 } 0.8540: 3 9.99572 ) 2 \ 0.8531! 2 9.99577 * 1 2 0.8522 C 9.9957c ) 0 c. L.Tanj g. L. Sin ! P. P. 105 10.5 12.3 14.0 15.8 17.5 35.0 52.5 70.0 87.5 102 6 ! 10.2 11.9 13.6 15.3 17.0 34.0 51.0 68.0 85.0 104 10.4 12.1 13.9 15.6 17.3 34.7 52.0 69.3 86.7 101 10.1 11.8 13.5 15.2 16.8 33.7 50.5 67.3 84.2 103 10.3 12.0 13.7 15.5 17.2 34.3 51.5 68.7 85.8 100 10.0 11.7 13.3 -15.0 16.7 33.3 50.0 66.7 83.3 99 9.9 11.6 13.2 14.9 16.5 33.0 49.5 66.0 82.5 98 9.8 11.4 13.1 14.7 16.3 32.7 49.0 65.3 81.7 97 9.7 11.3 12.9 14.6 16.2 32.3 48.5 64.7 80.8 94 9.4 11.0 12.5 14.1 15.7 31.3 47.0 62.7 78.3 96 9.6 11.2 12.8 14.4 16.0 32.0 48.0 64.0 80.0 93 9.3 10.9 12.4 14.0 15.5 31.0 46.5 62.0 77.5 91 9.1 10.6 12.1 13.7 15.2 30.3 45.5 60.7 75.8 90 I 9.0 1 10.5 12.0 13.5 15.0 30.0 45.0 60.0 75.0 95 9.5 11.1 12.7 14.3 15.8 31.7 47.5 63.3 79.2 92 9.2 10.7 12.3 13.8 15.3 30.7 46.0 61.3 76.7 I 2 0.2 0.2 0.3 0.3 0.3 0.7 1.0 1.3 1.7 P. P. 82 ° 500 LOGARITHMS OF TRIGONOMETRIC FUNCTIONS 8 ° / L. Sin. d. L.Tang. d. c. L. Cotg. L. Cos. P. p. 0 9.14356 9.14780 0.85220 9.99575 60 1 9.14445 89 9.14872 92 0.85128 9.99574 59 ! SI 90 2 9.14535 90 9.14963 91 0.85037 9.99572 58 6 9.2 | 9.1 9.0 B 9.14624 89 9.15054 91 0.84946 9.99570 57 7 10.7 10.6 10.5 4 9.14714 90 89 9.15145 91 91 0.84855 9.99568 56 8 9 12.3 J3.8 1 12.1 13.7 12.0 13.5 5 9.14803 9.15236 0.84764 9.99566 55 10 15^3 15^2 15.0 6 9.14891 88 9.15327 91 0.84673 9.99565 54 20 30.7 30.3 30.0 7 9.14980 sy 9.15417 90 0.84583 9.99563 53 30 46.0 ! 45.5 45.0 8 9.15069 »y 9.15508 9L 0.84492 9.99561 52 40 61.3 1 60.7 60.0 9 9.15157 8 o 88 9.15598 90 90 0.84402 9.99559 51 50 76.7 i 75.8 75.0 10 9.15245 9.15688 0.84312 9.99557 50 11 9.15333 88 9.15777 89 0.84223 9.99556 49 89 88 12 9.15421 88 9.15867 90 0.84133 9.99554 48 6 1 8.9 8.8 13 9.15508 87 9.15956 89 0.84044 9.99552 47 7 i 10.4 10.3 14 9.15596 88 87 9.16046 90 89 0.83954 9.99550 46 8 A i 11.9 ! 1 Q A 11.7 IQ O 15 9.15683 9.16135 0.83865 9.99548 45 V 10 lo.4 14.8 lo. Z 14.7 16 9.15770 o7 9.16224 89 0.83776 9.99546 44 20 1 20.7 90 17 9.15857 8 / 9.16312 88 0.83688 9.99545 43 30 44.5 L. J.O 44.0 18 9.15944 g7 9.16401 89 0.83599 9.99543 42 40 1 593 58.7 19 9.16030 ob 86 9.16489 88 88 0.83511 9.99541 41 50 ! 74.2 73^3 20 9.16116 9.16577 0.83423 9.99539 40 21 9.16203 8 / 9.16665 88 0.83335 9.99537 39 87 86 22 9.16289 86 9.16753 88 0.83247 9.99535 38 6 8.7 8.6 23 9.16374 85 9.16841 88 0.83159 9.99533 37 7 10.2 10.0 24 9.16460 86 85 9.16928 87 qq 0.83072 9.99532 36 8 11.6 11.5 25 9.16545 9.17016 0.82984 9.99530 35 y 1 A 13.1 12.9 26 9.16631 86 9.17103 87 0.82897 9.99528 34 10 14.5 14.3 27 9.16716 85 9.17190 87 0.82810 9.99526 33 20 on 29.0 AO K 28.7 28 9.16801 85 9.17277 87 0.82723 9.99524 32 30 A A CQ A 43.0 cr? o 29 9.16886 85 84 or; 9.17363 86 87 0.82637 9.99522 31 40 RO Oo.U 79 * 5/.o 71 7 30 9.16970 9.17450 0.82550 9.99520 30 31 9.17055 85 O/l 9.17536 86 0.82464 9.99518 29 85 84 32 9.17139 84 9.17622 86 0.82378 9.99517 28 6 8.5 8.4 33 9.17223 84 0/4 9.17708 86 0.82292 9.99515 27 7 9.9 9.8 34 9.17307 84 84 9.17794 86 86 0.82206 9.99513 26 8 11.3 11.2 35 9.17391 9.17880 0.82120 9.99511 25 9 12.8 12.6 36 9.17474 83 9.17965 85 0.82035 9.99509 24 10 14.2 14.0 37 9.17558 84 9.18051 86 0.81949 9.99507 23 20 28.3 28.0 38 9.17641 83 9.18136 85 0.81864 9.99505 22 30 42.5 42.0 39 9.17724 83 83 QO 9.18221 85 85 0.81779 9.99503 21 40 ! £;a 56.7 '7A Q 56.0 >7 n n 40 9.17807 9.18306 0.81694 9.99501 20 • V / ;j 41 9.17890 oS QO 9.18391 85 0.81609 9.99409 19 83 82 42 9.17973 GO QO 9.18475 84 0.81525 9.99497 18 6 8.3 8.2 43 9.18055 oZ QO 9.18560 85 O A 0.81440 9.99495 17 7 9.7 9.6 44 9.18137 oZ 83 9.18644 g4 84 0.81356 9.99494 16 8 11.1 10.9 45 9.18220 9.18728“ 0.81272 9.99492 15 9 12.5 12.3 46 9.18302 82 Q 1 9.18812 84 0.81188 9.99490 14 JO 13.8 13.7 47 9.18383 ol QO 9.18896 84 0.81104 9.99488 13 20 27.7 27.3 ! 48 9.18465 oZ 9.18979 83 0.81021 9.99486 12 30 41.5 41.0 49 9.18547 82 81 9.19063 84 83 0.80937 9.99484 11 40 55.3 £Q O 54.7 £Q O 50 9.18628 Q t 9.19146 0.80854 9.99482 10 OU oy . z DO.O | 51 9.18709 ol Q1 9.19229 83 0.80771 9.99480 9 81 80 9 52 9.18790 ol 9.19312 83 0.80688 9.99478 8 6 8.1 8.0 0.2 53 9.18871 G1 Q1 9.19395 83 QO 0.80605 9.99476 fT ! 7 9.5 9.3 0 2 54 9.18952 G± 81 9.19478 GO 83 0.80522 9.99474 6 8 10.8 10.7 0.3 55 9.19033 qh 9.19561 0.80439 9.99472 5 9 12.2 12.0 0.3 56 9.19113 oU QO 9.19643 82 0.80357 9.99470 4 10 13.5 13.3 0.3 57 9.19193 oU QO 9.19725 82 0.80275 9.99468 3 20 27.0 26.7 0.7 58 9.19273 GU QO * 9.19807 82 0.80193 9.99466 2 30 40.5 40.0 1.0 59 9.19353 oU 80 9.19889 82 82 0.80111 9.99464 1 40 54.0 ; 53.3 1.3 60 9.19433 9.19971 0.80029 9.99462 0 50 67.5 i 66.7 1.7 L. Cos. d. L. Cotg. d. c. L.Tang. L. Sin. t p. P. 81 ° LOGARITHMS OF TRIGONOMETRIC FUNCTIONS. 501 t L. Sin. < 0 9.19433 , 1 9.19513 ; 2 9.19592 3 9.19672 ; 4 9.19751 5 9.19830 6 9.19909 7 9.19988 8 9.20067 9 9.20145 10 9.20223 11 9.20302 12 9.20380 13 9.20458 14 9.20535 15 9.20613 16 9.20691 17 9.20768 18 9.20845 19 9.20922 20 0.20999 21 9.21076 22 9.21153 23 9.21229 24 9.21306 25 9.21382 26 9.21458 27 9.21534 28 9.21610 29 9.21685 30 9.21761 31 9.21836 32 9.21912 33 9.21987 34 9.22062 35 9.22137 36 9.22211 37 9.22286 38 9.22361 39 9.22435 40 9.22509 41 9.22583 42 9.22657 43 9.22731 44 9.22805 45 9.22878 46 9.22952 47 9.23025 48 9.23098 49 9.23171 50 ' 9.23244 51 9.23317 52 9.23390 53 9.23462 54 9.23535 55 9.23607 56 9.23679 57 9.23752 58 9.23823 59 9.23895 60 9.23967 L. Cos. L. Cotg. L. Cos. 0.80029 9.99462 l BO 0.79947 9.99460 59 0.79866 9.99458 58 0.79784 9.99456 57 0.79703 9.99454 56 0.79622 9.99452 55 ] 0.79541 9.99450 54 $ 0.79460 9.99448 53 £ 0.79379 9.99446 52 t 0.79299 9 99444 51 l 0.79218 9.99442 50 0.79138 9.99440 49 0.79058 9.99438 48 0.78978 9.99436 47 0.78898 9.99434 46 0.78818 9.99432 45 0.78739 9.99429 44 0.78659 9.99427 43 0.78580 9.99425 42 0.78501 9.99423 41 0.78422 9.99421 40 0.78343 9.99419 39 0.78264 9.99417 38 0.78186 9.99415 37 0.78107 9.99413 36 0.78029 9.99411 35 0.77951 9.99409 34 0.77873 9.99407 33 0.77795 9.99404 32 0.77717 9.99402 31 0.77639 9.99400 30 0.77562 9.99398 29 0.77484 9.99396 28 0.77407 9.99394 27 0.77330 9.99392 26 0.77253 9.99390 25 0.77176 9.99388 24 0.77099 9.99385 23 0.77023 9.99383 22 0.76946 9.99381 21 0.76870 9.99379 20 0.76794 9.99377 19 0.76717 9.99375 18 0.76641 9.99372 17 0.76565 9.99370 16 0.76490 9.99368 15 0.76414 9.99366 14 0.76339 9.99364 13 0.76263 9.99362 12 0.76188 9.99359 ' 11 0.76113 " 9.99357 10 0.76038 9.99355 9 0.75963 9.99353 8 0.75888 9.99351 7 0.75814 9.99348 6 0.75739 ' 9.99346 5 0.75665 . 9.99344 4 1 0.75590 i 9.99342 ; 3 0.75516 i 9.99340 i 2 ■ 0.75442 \ 9.99337 ’ 1 0.7536* 5 9.9933E » 0 c. L.Tang f. L. Sin. f d. 79 80 79 79 79 79 79 78 78 79 78 78 77 78 78 77 77 77 77 77 77 76 77 76 76 76 76 75 76 75 76 75 75 75 74 75 75 74 74 74 74 74 74 73 74 73 73 73 73 73 73 72 73 72 72 73 71 72 72 d. Tang. .19971 .20053 .20134 .20216 .20297 20378 20459 .20540 .20621 .20701 20782 9.20862 9.20942 9.21022 9.21102 d. c. 9.21182 9.21261 9.21341 9.21420 9.21499 9.21578 9.21657 9.21736 9.21814 9.21893 9.21971 9.22049 9.22127 9.22205 9.22283 9.22361 9.22438 9.22516 9.22593 9.22670 9.22747 9.22824 9.22901 9.22977 9.23054 9.23130 9.23206 9.23283 9.23359 9.23435 9.23510 9.23586 9.23661 9.23737 9.23812 9.23887 9.23962 9.24037 9.24112 9.24186 9.24261 9.24335 9.24410 9.24484 9.24558 82 81 82 81 81 81 81 81 80 81 80 80 80 80 80 79 80 79 79 79 79 79 78 79 78 78 78 78 78 78 77 78 77 77 77 77 77 76 77 76 76 77 76 76 75 76 75 76 75 75 75 75 75 74 9.24632 L. Cotg. P. P. 82 81 80 8.2 8.1 8.0 9.6 9.5 9.3 10.9 10.8 10.7 12.3 12.2 12.0 13.7 13.5 13.3 27.3 27.0 26.7 41.0 40.5 40.0 54.7 54.0 53.3 68.3 67.5 66.7 6 i ?! 9 10 20 30 40 50 6 7 8 9 10 20 30 40 50 6 7 8 9 10 20 30 40 50 79 7.9 9.2 10.5 11.9 13.2 26.3 39.5 52.7 65.8 77 7.7 9.0 10.3 11.6 12.8 25.7 38.5 51.3 64.2 75 7.5 8.8 10.0 11.3 12.5 25.0 37.5 50.0 62.5 73 7.3 8.5 9.7 11.0 12.2 24.3 36.5 48.7 60.8 71 78 7.8 9.1 10.4 11.7 13.0 26.0 39.0 52.0 65.0 76 7.6 8.9 10 . 1 ' 11.4 12.7 25.3 38.0 50.7 63.3 74 7.4 8.6 9.9 11.1 12.3 24.7 37.0 49.3 61.7 72 7.2 8.4 9.6 10.8 12.0 24.0 36.0 48.0 60.0 3 80 7.1 0.3 0.2 8.3 0.4 0.2 9.5 0.4 0.3 10.7 0.5 0.3 11.8 0.5 0.3 23.7 1.0 0.7 35.5 1.5 1.0 47.3 2.0 1.3 59.2 2.5 1.7 P. P. 502 LOGARITHMS OF TRIGONOMETRIC FUNCTIONS. 10 ° / L. Sin. d. L.Tang. d. c. L. Cotg. L. Cos. P. P. 0 1 2 3 4 9.23967 9.24039 9.24110 9.24181 9.24253 72 71 71 72 71 71 71 70 71 70 71 70 70 70 70 70 70 69 70 69 69 69 69 69 69 69 68 69 68 68 68 68 68 68 68 67 68 67 67 67 67 67 67 67 66 67 66 67 66 66 66 66 65 66 66 65 65 66 65 65 9.24632 9.24706 9.24779 9.24853 9.24926 74 73 74 73 74 73 73 73 73 73 72 73 72 73 72 72 72 72 72 71 72 71 72 71 71 71 71 70 71 71 70 70 71 70 70 70 70 69 70 69 70 69 69 69 69 69 69 69 68 69 68 69 68 68 68 68 67 68 68 67 0.75368 0.75294 0.75221 0.75147 0.75074 9.99335 9.99333 9.99331 9.99328 9.99326 60 59 58 57 56 6 7 8 9 10 20 30 40 50 6 7 8 9 10 20 30 40 50 6 7 8 9 10 20 30 40 50 6 7 1 8 9 10 20 30 40 50 6 7 8 9 10 20 30 40 50 6 7 8 9 10 10 30 40 50 74 7.4 8.6 9.9 11.1 12.3 24.7 37.0 49.3 61.7 72 7.2 8.4 9.6 10.8 12.0 24.0 36.0 48.0 60.0 70 7.0 8.2 9.3 10.5 11.7 23.3 35.0 46.7 58.3 68 6.8 7.9 9.1 10.2 11.3 22.7 34.0 45.3 56.7 66 6.6 7.7 8.8 9.9 11.0 22.0 33.0 44.0 55.0 3 0.3 0.4 0.4 0.5 0.5 1.0 1.5 2.0 2.5 73 7.3 8.5 9.7 11.0 12.2 24.3 36.5 48.7 60.8. 71 7.1 8.3 9.5 10.7 11.8 23.7 35.5 47.3 59.2 69 6.9 8.1 9.2 10.4 11.5 23.0 34.5 46.0 57.5 67 6.7 7.8 8.9 10.1 11.2 22.3 33.5 44.7 55.8 65 6.5 , 7.6 8.7 9.8 10.8 21.7 32.5 43.3 54.2 2 0.2 0.2 0.3 0.3 0.3 0.7 ! 1.0 1.3 1.7 5 6 7 8 9 9.24324 9.24395 9.24466 9.24536 9.24607 9.25000 9.25073 9.25146 9.25219 9.25292 0.75000 0.74927 0.74854 0.74781 0.74708 9.99324 9.99322 9.99319 9.99317 9.99315 55 54 53 52 51 10 11 12 13 14 9.24677 9.24748 9.24818 9.24888 9.24958 9,25365 9.25437 9.25510 9.25582 9.25655 0.74635 0.74563 0.74490 0.74418 0.74345 9.99313 9.99310 9.99308 9.99306 9.99304 50 49 48 47 46 15 16 17 18 19 9.25028 9.25098 9.25168 9.25237 9.25307 9.25727 9.25799 9.25871 9.25943 9.26015 0.74273 0.74201 0.74129 0.74057 0.73985 9.99301 9.99299 9.99297 9.99294 9.99292 45 44 43 42 41 20 21 22 23 24 9.25376 9.25445 9.25514 9.25583 9.25652 9.26086 9.26158 9.26229 9.26301 9.26372 0.73914 0.73842 0.73771 0.73699 0.73628 9.99290 9.99288 9.99285 9.99283 9.99281 40 39 38 37 36 25 26 27 28 29 9.25721 9.25790 9.25858 9.25927 9.25995 9.26443 9.26514 9.26585 9.26655 9.26726 0,73557 0.73486 0.73415 0.73345 0.73274 9.99278 9.99276 9.99274 9.99271 9.99269 35 34 33 32 31 30 31 32 33 34 9.26063 9.26131 9.26199 9.26267 9.26335 9.26797 9.26867 9.26937 9.27008 9.27078 0.73203 0.73133 0.73063 0.72992 0.72922 9.99267 9.99264 9.99262 9.99260 9.99257 30 29 28 27 26 35 36 37 38 39 9.26403 9.26470 9.26538 9.26605 9.26672 9.27148 9.27218 9.27288 9.27357 9.27427 0.72852 0.72782 0.72712 0.72643 0.72573 9.99255 9.99252 9.99250 9.99248 9.99245 25 24 23 22 21 40 41 42 43 44 9.26739 9.26806 9.26873 9.26940 9.27007 9.27496 9.27566 9.27635 9.27704 9.27773 0.72504 0.72434 0.72365 0.72296 0.72227 9.99243 9.99241 9.99238 9.99236 9.99233 20 19 18 17 16 45 46 47 48 49 9.27073 9.27140 9.27206 9.27273 9.27339 9.27842 9.27911 9.27980 9.28049 9.28117 0.72158 0.72089 0.72020 0.71951 0.71883 9.99231 9.99229 9.99226 9.99224 9.99221 15 14 13 12 11 50 51 52 53 54 9.27405 9.27471 9.27537 9.27602 9.27668 9.28186 9.28254 9.28323 9.28391 9.28459 0.71814 0.71746 0.71677 0.71609 0.71541 9.99219 9.99217 9.99214 9.99212 9.99209 10 9 8 7 6 t>5 56 57 58 59 9.27734 9.27799 9.27864 9.27930 9.27995 9.28527 9.28595 9.28662 9.28730 9.28798 0.71473 0.71405 0.71338 0.71270 0.71202 9.99207 9.99204 9.99202 9.99200 9.99197 5 4 3 2 1 60 9.28060 9.28865 0.71135 9.99195 0 L. Cos. d. L. Cotg. d. c. L.Tang. L. Sin. f P. P. 79 ° LOGARITHMS OF TRIGONOMETRIC FUNCTIONS. 11 ° 503 / L. Sin. d. I j. Tang. d. c. L. Cotg. L. Cos. P. P. o 9.28060 9.28865 0.71135 9.99195 60 fif t 6 1 9.28125 65 9.28933 68 0.71007 9.99192 59 6 6.8 6 2 9.28190 65 9 29000 67 0.71000 9.99190 58 7 7.9 7 3 9.28254 64 9.29067 67 0.70933 9.99187 57 8 9.1 8 4 9.28319 65 9.29134 67 0.70866 9.99185 56 9 10.2 10 9.28384 65 9.29201 0.70799 9.99182 55 10 11.3 11 6 9.28448 64 9.29268 67 0.70732 9.99180 54 20 22.7 22 7 9.28512 64 9.29335 67 0.70665 9 99177 53 30 34.0 33 8 9.28577 65 9.29402 67 0.70598 9.99175 52 40 45 3 44 9 9.28641 64 9.29468 & , 0.70532 9.99172 51 50 56.7 55 10 9.28705 64 9.29535 0.70465 9.99170 50 cc 11 9.28769 64 9.29601 66 0.70399 9.99167 49 A uu A A 12 9.28833 64 9.29668 67 0.70332 9.99165 48 O 7 0.0 7 7 13 9.28896 63 9.29734 66 0.70266 9.99162 47 i Q ft ft 14 9.28960 64 9.29800 66 66 - 0.70200 9.99160 46 O 9 0.0 9.9 15 9.29024 64 9.29866 0.70134 9.99157 45 10 li.o : 16 9.29087 63 9.29932 66 0.70068 9.99155 44 20 22.0 : 17 9.29150 63 9.29998 66 0.70002 9.99152 43 30 33.0 ! 18 9.29214 64 9.30064 66 0.69936 9.99150 42 40 44.0 - 19 9.29277 63 9.30130 66 65 0.69870 9.99147 41 50 55.0 1 20 9.29340 bo 9.30195 0.69805 9.99145 40 21 9.29403 63 9.30261 66 0.69739 9.99142 39 64 22 9.29466 63 9.30326 65 0.69674 9.99140 38 6 0 .3. : M C 23 9.29529 63 9.30391 65 0.69609 9.99137 37 7.5 24 9.29591 62 9.30457 66 65 0.69543 9.99135 36 9 8.5 j Q fi 25 9.29654 60 9.30522 0.69478 9.99132 35 10 10.7 j 26 9.29716 62 9.30587 65 0.69413 9.99130 34 20 21.3 27 9.29779 63 9.30652 65 0.69348 9.99127 33 30 32.0 28 9.29841 62 9.30717 65 0.69283 9.99124 32 40 42.7 29 9.29903 62 no 9.30782 65 64 0.69218 9.99122 31 50 53.3 30 9.29966 DO 9.30846 vr± 0.69154 9.99119 30 31 9.30028 62 9.30911 65 0.69089 9.99117 29 62 32 9.30090 62 9.30975 64 0.69025 9.99114 28 6 6.2 33 9.30151 61 9.31040 65 0.68960 9.99112 27 7 7.2 34 9.30213 62 9.31104 64 64 0.68896 9.99109 26 8 8.3 35 9.30275 62 9.31168 Cr± /»r 0.68832 9.99106 25 y 10 y.o 10 8 36 9.30336 61 9.31233 65 0.68767 9.99104 24 J.U 90 1U.O 90 7 37 9.30398 62 9.31297 64 0.68703 9.99101 23 ZU Qfk ZU. 1 31.0 38 9.30459 61 9.31361 64 0.68639 9.99099 22 OU 40 41.3 39 9.30521 62 61 9.31425 64 64 0.68575 9.99096 21 1U 50 51.7 40 9.30582 9.31489 0.68511 9.99093 20 41 9.30643 61 9.31552 63 0.68448 9.99091 19 60 42 9.30704 61 9.31616 64 0.68384 9.99088 18 6 6.0 43 9.30765 61 9.31679 63 0.68321 9.99086 17 7 7.0 44 9.30826 61 9.31743 64 63 0.68257 9.99083 16 8 8.0 45 9.30887 61 9.31806 0.68194 9.99080 15 9 9.0 46 9.30947 60 9.31870 64 0.68130 9.99078 14 1U 1U.U 47 9.31008 61 9.31933 63 0.68067 9.99075 13 20 20.0 48 9.31068 60 9.31996 63 0.68004 9.99072 12 30 30.0 49 9.31129 61 V»A 9.32059 63 63 0.67941 9.99070 11 40 *0 40.0 fiO 0 50 9.31189 oU 9.32122 0.67878 9.99067 10 51 9.31250 61 9.32185 63 0.67815 9.99064 9 3 52 9.31310 60 9.32248 63 0.67752 9.99062 8 < 5 0.3 53 9.31370 60 9.32311 63 0.67689 9.99059 7 1 7 0.4 54 9.31430 60 AH 9.32373 62 63 0.67627 9.99056 6 8 0.4 55 9.31490 bU 9.32436 0.67564 9.99054 5 . ( 3 0.5 56 9.31549 59 9.32498 62 0.67502 : 9.99051 4 10 0.5 57 9.31609 60 9.32561 63 0.67439 9.99048 3 20 1.0 58 9.31669 60 9.32623 62 0.67377 9.99046 i 2 30 1.5 1 59 9.31728 59 ' AH 9.32685 62 62 0.67315 i 9.99043 1 40 2.0 9 60 9.31788 r 60 9.32747 0.67253 ; 9.99040 i 0 OU Z.D I L. Cos d. L. Cotg d. c. L.Tang L. Sin. t P . P 65 6.5 7.6 8.7 9.8 63 6.3 7.4 8.4 9.5 10.5 21.0 31.5 42.0 52.5 6i 6.1 7.1 8.1 9.2 10.2 20.3 30.5 40.7 50.8 59 5.9 6.9 7.9 8.9 9.8 19.7 29.5 39.3 49.2 2 0.2 0.2 0.3 0.3 0.3 0.7 1.0 1.3 1.7 78 ° 504 LOGARITHMS OF TRIGONOMETRIC FUNCTIONS. 12 ° / L. Sin. d. L.Tang. d. c. L. Cotg. L. Cos. P. P. 0 9.31788 9.32747 0.67253 9.99040 60 1 9.31847 59 9.32810 63 0.67190 9.99038 59 DO 62 2 9.31907 60 9.32872 62 0.67128 9.99035 58 6 6.3 ff A 6.2 3 9.31966 59 9.32933 61 0.67067 9.99032 57 7 7.4 7.2 j 4 9.32025 59 59 9.32995 62 62 0.67005 9.99030 56 8 9 8.4 9.5 8.3 9.3 ' 5 9.32084 9.33057 0.66943 9.99027 55 10 10*5 io!3 6 9.32143 59 9.33119 62 0.66881 9.99024 54 20 21.0 20.7 7 9.32202 59 9.33180 61 0.66820 9.99022 53 30 31.5 31.0 8 9.32261 59 9.33242 62 0.66758 9.99019 52 40 42.0 41.3 9 9.32319 58 9.33303 61 62 0.66697 9.99016 51 50 52.5 51.7 10 9.32378 9.33365 0.66635 9.99013 50 11 9.32437 59 9.33426 61 0.66574 9.99011 49 61 60 12 9.32495 58 9.33487 61 0.66513 9.99008 48 6 6.1 6.0 13 9.32553 58 9.33548 61 0.66452 9.99005 47 7 7.1 7.0 14 9.32612 59 58 9.33609 61 61 0.66391 9.99002 46 8 Q 8.1 Q O 8.0 . Q A 15 9.32670 9.33670 0.66330 9.99000 45 y 10 y.z 10.2 y.u 10.0 16 9.32728 58 9.33731 61 0.66269 9.98997 44 20 on q 20.0 17 9.32786 58 9.33792 61 0.66208 9.98994 43 30 so 5 30.0 18 9.32844 58 9.33853 61 0.66147 9.98991 42 40 407 4o!o 19 9.32902 58 9.33913 60 61 0.66087 9.98989 41 50 50^8 5o!o 20 9.32960 9.33974 0.66026 9.98986 40 21 9.33018 58 9.34034 60 0.65966 9.98983 39 59 22 9.33075 57 9.34095 61 0.65905 9.98980 38 6 5.9 23 9.33133 58 9.34155 60 0.65845 9.98978 37 7 6.9 24 9.33190 57 9.34215 60 61 0.65785 9.98975 36 8 7.9 25 9.33248 Oo 9.34276 0.65724 9.98972 35 9 1 A 8.9 Q Q 26 9.33305 57 9.34336 60 0.65664 9.98969 34 10 OA y.s in 7 27 9.33362 57 9.34396 60 0.65604 9.98967 33 20 QA iy.7 on 28 9.33420 58 9.34456 60 0.65544 9.98964 32 30 zy.o on o 29 9.33477 57 9.34516 60 60 0.65484 9.98961 31 40 Aft i oy .6 1 4Q 9 30 9.33534 O/ 9.34576 0.65424 9.98958 30 31 9.33591 57 9.34635 59 0.65365 9.98955 29 58 57 32 9.33647 56 9.34695 60 0.65305 9.98953 28 6 5.8 5.7 33 9.33704 57 9.34755 60 0.65245 9.98950 27 7 6.8 6.7 34 9.33761 57 57 9.34814 59 60 0.65186 9.98947 26 8 7.7 7.6 35 9.33818 9.34874 0.65126 9.98944 25 9 8.7 8.6 36 9.33874 56 9.34933 59 0.65067 9.98941 24 10 9.7 9.5 37 9.33931 57 9.34992 59 0.65008 9.98938 23 20 19.3 19.0 38 9.33987 56 9.35051 59 0.64949 9.98936 22 30 29.0 28.5 39 9.34043 56 9.35111 60 fSQ 0.64889 9.98933 21 40 50 38.7 AQ Q 38.0 47.5 40 9.34100 0/ 9.35170 V** 0.64830 9.98930 20 41 9.34156 56 9.35229 59 0.64771 9.98927 19 56 55 42 9.34212 56 9.35288 59 0.64712 9.98924 18 6 5.6 5.5 43 9.34268 56 9.35347 59 0.64653 9.98921 17 7 6.5 6.4 44 9.34324 56 56 9.35405 58 59 0.64595 9.98919 16 8 7.5 7.3 45 9.34380 9.35464 0.64536 9.98916 15 9 8.4 8.3 46 9.34436 56 9.35523 59 0.64477 9.98913 14 10 9.3 9.2 47 9.34491 55 9.35581 58 0.64419 9.98910 13 20 18.7 .18.3 48 9.34547 56 9.35640 59 0.64360 9.98907 12 30 28.0 27.5 49 9.34602 55 9.35698 58 0.64302 9.98904 11 40 37.3 36.7 59 50 45.8 50 9.34658 oo 9.35757 0.64243 9.98901 10 4:0. t 51 9.34713 55 9.35815 58 0.64185 9.98898 9 3 2 52 9.34769 56 9.35873 58 0.64127 9.98896 8 a 0.3 0.2 53 9.34824 55 9.35931 58 0.64069 9.98893 7 7 0.4 0.2 54 9.34879 55 55 9.35989 58 58 0.64011 9.98890 6 8 0.4 0.3 55 9.34934 9.36047 0.63953 9.98887 5 9 0.5 0.3 56 9.34989 55 9.36105 58 0.63895 9.98884 4 10 0.5 0.3 57 9.35044 55 9.36163 58 0.63837 9.98881 3 20 1.0 0.7 58 9.35099 55 9.36221 58 ■ 0.63779 9.98878 2 30 1.5 1.0 59 9.35154 55 9.36279 58 0.63721 9.98875 1 40 2.0 1.3 55 57 1.7 60 9.35209 9.36336 0.63664 9.98872 0 i ou A. 0 L. Cos. d. L. Cotg. d. c. L.Tang. L. Sin. t P. P. 77 ° LOGARITHMS OF TRIGONOMETRIC FUNCTIONS. 13 ° 505 r L. Sin. 0 9.35209 1 9.35263 2 9.35318 3 9.35373 4 9.35427 5 9.35481 6 9.35536 7 9.35590 8 9.35644 9 9.35698 10 9.35752 11 9.35806 12 9.35860 13 9.35914 14 9.35968 15 9.36022 16 9.36075 17 9.36129 18 9.36182 19 9.36236 20 9.36289 21 9.36342 22 9.36395 23 9.36449 24 9.36502 25 9.36555 26 9.36608 27 9.36660 28 9.36713 29 9.36766 30 9.36819 31 9.36871 32 9.36924 33 9.36976 34 9.37028 35 9.37081 36 9.37133 37 9.37185 38 9.37237 39 9.37289 40 9.37341 41 9.37393 42 9.37445 43 9.37497 44 9.37549 45 9.37600 46 9.37652 47 9.37703 48 9.37755 49 9.37806 50 9.37858 51 9.37909 52 9.37960 53 9.38011 54 9.38062 55 9.38113 56 9.38164 57 9.38215 58 9.38266 59 9.38317 60 9.38368 L. Cos. d. 54 55 55 54 54 55 54 54 54 54 54 54 54 54 54 53 54 53 54 53 53 53 54 53 53 53 52 53 53 53 52 53 52 52 53 52 52 52 52 52 52 52 52 52 51 52 51 52 51 52 51 51 51 51 51 51 51 51 51 d. L.Tang. 6 9.36336 9.36394 9.36452 9.36509 9.36566 9.36624 9.36681 9.36738 9.36795 9.36852 9.36909 9.36966 9.37023 9.37080 9.37137 9.37193 9.37250 9.37306 9.37363 9.37419 9.37476 9.37532 9.37588 9.37644 9.37700 9.37756 9.37812 9.37868 9.37924 9.37980 9.38035 9.38091 9.38147 9.38202 9.38257 9.38313 9.38368 9.38423 9.38479 9.38534 9.38589 9.38644 9.38699 9.38754 9.38808 9.38863 9.38918 9.38972 9.39027 9.39082 9.39136 9.39190 9.39245 9.39299 9.3935a 9.39407 9.39461 9.39515 9.39569 9.39623 9.39677 L. Cotg. d .c. 58 58 57 57 58 57 57 57 57 57 57 57 57 57 56 57 56 57 56 57 56 56 56 56 56 56 56 56 56 55 56 56 55 55 56 55 55 56 55 55 55 55 55 54 55 55 54 55 55 54 54 55 54 54 54 54 54 54 54 L. Cotg. L. Cos. 0.63004 9.98872 60 0.63606 9.98869 59 0.63548 9.98867 58 0.63491 9.98864 57 0.63434 9.98861 56 0.63376 9.98858 55 0.63319 9.98855 54 0.63262 9.98852 53 0.63205 9.98849 52 0.63148 9.98846 51 0.63091 9.98843 50 0.63034 9.98840 49 0.62977 9.98837 48 0.62920 9.98834 47 0.62863 9.98831 46 0.62807 9.98828 45 0.62750 9.98825 44 0.62694 9.98822 43 0.62637 9.98819 42 0.62581 9.98816 41 0.62524 9.98813 40 0.62468 9.98810 39 0.62412 9.98807 38 0.62356 9.98804 37 0.62300 9.98801 36 0.62244 9.98798 35 0.62188 9.98795 34 0.62132 9.98792 33 0.62076 9.98789 32 0.62020 9.98786 31 0.61965 9.98783 30 0.61909 9.98780 29 0.61853 9.98777 28 0.61798 9.98774 27 0.61743 9.98771 26 0.61687 9.98768 25 0.61632 9.98765 24 0.61577 9.98762 23 0.61521 9.98759 22 0.61466 9.98756 21 0.61411 9.98753 20 0.61356 9.98750 19 0.61301 9.98746 18 0.61246 9.98743 17 0.61192 9.98740 16 0.61137 9.98737 15 0.61082 9.98734 14 0.61028 9.98731 13 0.60973 9.98728 12 0.60918 9.98725 11 0.60864 9.98722 10 0.60810 9.98719 9 0.60755 i 9.98715 8 0.60701 9.98712 7 0.60647 ’ 9.98709 6 0.60593 1 9.98706 5 0.6053S 1 9.98703 : 4 0.60485 1 9.98700 i 3 0.60431 L 9.98697 ' 2 0.60377 t 9.98694 l 1 0.6032; 1 9.9869C ) 0 3. L.Tang r. L. Sin, / P. P. 58 5.8 6.8 7.7 8.7 9.7 19.3 29.0 38.7 48.3 56 5.6 6.5 7.5 8.4 9.3 18.7 28.0 37.3 46.7 57 5.7 6.7 7.6 8.6 9.5 19.0 28.5 38.0 47.5 55 5.5 6.4 7.3 8.3 9.2 18.3 27.5 36.7 45.8 6 7 8 9 10 20 30 40 50 54 5.4 6.3 7.2 8.1 9.0 18.0 27.0 36.0 45.0 6 7 8 9 10 20 30 40 50 6 7 8 9 10 20 30 40 50 6 7 8 9 10 20 30 40 50 53 5.3 6.2 7.1 8.0 8.8 17.7 26.5 35.3 44.2 51 5.1 6.0 6.8 7.7 8.5 17.0 25.5 34.0 42.5 3 0.3 0.4 0.4 0.5 0.5 1.0 1.5 2.0 2.5 52 5.2 6.1 6.9 7.8 8.7 17.3 26.0 34.7 43.3 4 0.4 0.5 0.5 0.6 0.7 1.3 2.0 2.7 3.3 2 0.2 0.2 0.3 0.3 0.3 0.7 1.0 1.3 1.7 P. P. 76 506 LOGARITHMS OF TRIGONOMETRIC FUNCTIONS. 14 ° t L. Sin. d. L.Tang. d. c. L. Cotg. L. Cos. d. P. P 0 9.38368 9.39677 0.60323 9.98690 60 1 9.38418 50 9.39731 54 0.60269 9.98687 3 59 2 9.38469 51 9.39785 54 0.60215 9.98684 3 58 3 9.38519 50 9.39838 53 0.60162 9.98681 3 57 54 53 4 9.38570 51 50 9.39892 54 53 0.60108 9.98678 3 q 56 6 7 5.4 6.3 5.3 fi 9 5 9.38620 9.39945 0.60055 9.98675 6 55 8 in 7.1 6 9.38670 50 9.39999 54 0.60001 9.98671 4 54 9 8.1 8*0 7 9.38721 51 9.40052 53 0.59948 9.98668 3 53 10 9.0 8.8 8 9.38771 50 9.40106 54 0.59894 9.98665 3 52 20 18.0 ii .7 9 9.38821 50 50 9.40159 53 53 0.59841 9.98662 3 q 51 30 27.0 26.5 10 9.38871 9.40212 0.59788 9.98659 o 50 40 36.0 35.3 11 9.38921 50 9.40266 54 0.59734 9.98656 3 49 50 45.0 44.2 12 9.38971 50 9.40319 53 0.59681 9.98652 4 48 13 9.39021 50 9.40372 53 0.59628 9.98649 3 47 14 9.39071 50 50 9.40425 53 53 0.59575 9.98646 3 q 46 52 51 15 9.39121 9.40478 0.59522 9.98643 6 45 6 5.2 5.1 16 9.39170 49 9.40531 53 0.59469 9.98640 3 44 7 6.1 6.0 17 9.39220 50 9.40584 53 0.59416 9.98636 4 43 8 6.9 6.8 18 9.39270 50 9.40636 52 0.59364 9.98633 3 42 9 7.8 7.7 19 9.39319 49 50 9.40689 53 53 0.59311 9.98630 3 q 41 10 8.7 8.5 20 9.39369 9.40742 0.59258 9.98627 o 40 20 17.3 17.0 21 9.39418 49 9.40795 53 0.59205 9.98623 4 39 30 26.0 25.5 22 9.39467 49 9.40847 52 0.59153 9.98620 3 38 40 34.7 34.0 23 9.39517 50 9.40900 53 0.59100 9.98617 3 37 50 43.3 42.5 24 9.39566 49 9.40952 52 0.59048 9.98614 3 36 49 53 A 25 9.39615 9.41005 0.58995 9.98610 35 26 9.39664 49 9.41057 52 0.58943 9.98607 3 34 50 49 27 9.39713 49 9.41109 52 0.58891 9.98604 3 33 6 5.0 4.9 28 9.39762 49 9.41161 52 0.58839 9.98601 3 32 7 5.8 5.7 29 9.39811 49 49 9.41214 53 52 0.58786 9.98597 4 q 31 8 6.7 6.5 30 9.39860 9.41266 0.58734 9.98594 o 30 9 7 .5 7.4 31 9.39909 49 9.41318 52 0.58682 9.98591 3 29 10 8.3 8.2 32 9.39958 49 9.41370 52 0.58630 9.98588 3 28 20 16.7 16.3 33 9.40006 48 9.41422 52 0.58578 9.98584 4 27 30 25.0 24.5 34 9.40055 49 48 9.41474 52 52 0.58526 9.98581 3 q 26 40 50 66.6 41.7 32.7 40.8 35 9.40103 9.41526 0.58474 9.98578 o 25 36 9.40152 49 9.41578 52 0.58422 9.98574 4 24 37 9.40200 48 9.41629 51 0.58371 9.98571 3 23 38 9.40249 49 9.41681 52 0.58319 9.98568 3 22 48 47 39 9.40297 48 9.41733 52 0.58267 9.98565 3 21 6 4.8 4.7 49 51 A I *7 E K 40 9.40346 9.41784 0.58216 9.98561 20 / Q 0.0 ft d 0.0 41 9.40394 48 9.41836 52 0.58164 9.98558 3 19 O Q u.i 7 9 0.0 7 i 42 9.40442 48 9.41887 51 0.58113 9.98555 3 18 10 / .z q ft /.i 7 S 43 9.40490 48 9.41939 52 0.58061 9.98551 4 17 iU 90 o.U 1 ft ft / .o i f; 7 44 9.40538 48 48 9.41990 51 51 0.58010 9.98548 3 q 16 ZA) 30 10.0 24.0 19 . / 23.5 45 9.40586 9.42041 0.57959 9.98545 6 15 40 32.0 31.3 46 9.40634 48 9.42093 52 0.57907 9.98541 4 14 50 40.0 39.2 47 9.40682 48 9.42144 51 0.57856 9.98538 3 13 48 9.40730 48 9.42195 51 0.57805 9.98535 3 12 49 9.40778 48 47 9.42246 51 51 0.57754 9.98531 4 q 11 A 9 50 9.40825 9.42297 0.57703 9.98528 o 10 6 0.4 V 0.3 51 9.40873 48 9.42348 51 0.57652 9.98525 3 9 7 0.5 0.4 52 9.40921 48 9.42399 51 0.5760L 9.98521 4 8 8 0.5 0.4 53 9.40968 47 9.42450 51 0.57550 9.98518 3 7 9 0.6 0.5 54 9.41016 48 47 9.42501 51 51 0.57499 9.98515 3 A 6 10 0.7 0.5 55 9.41063 9.42552 0.57448 9.98511 ' 5 20 1.3 1.0 56 9.41111 48 9.42603 51 0.57397 9.98508 3 4 30 2.0 1.5 57 9.41158 47 9.42653 50 0.57347 9.98505 3 3 40 2.7 2.0 58 9.41205 47 9.42704 51 0.57296 9.98501 4 2 50 3.3 2.5 59 9.41252 47 48 9.42755 51 50 0.57245 9.98498 3 A 1 60 9.41300 9.42805 0.57195 9.98494 0 L. Cos. d. L. Cotg. d. c. L.Tang. L. Sin. d. t P. P. 75 ° logarithms of trigonometric functions. 507 ' ] Li. Sin. 6 o ( . 141300 . 1 < 141347 \ 2 1 141394 4 3 1 141441 4 4 ' 141488 4 5 1 141535 . 1 6 1 141582 4 1 7 1 9.41628 ; 8 1 9.41675 9 9.41722 ; 10 9.41768 11 9.41815 12 9.41861 13 9.41908 ; 14 9.41954 ; 15 9.42001 16 9.42047 17 9.42093 18 9.42140 19 9.42186 20 9.42232 21 9.42278 22 9.42324 23 9.42370 24 9.42416 25 9.42461 26 9.42507 27 9.42553 28 9.42599 29 9.42644 30 9.42690 31 9.42735 32 9.42781 33 9.42826 34 9.42872 35 9.42917 36 9.42962 37 9.43008 38 9.43053 39 9.43098 40 0.43143 41 9.43188 42 9.43233 43 9.43278 44 9.43323 45 ' 9.43367 46 9.43412 47 9.43457 48 9.43502 49 9.43546 50 “ 9.43591 51 9.43635 52 9.43680 53 9.43724 54 9.43769 55 ~ 9.43813 56 9.43857 57 9.43901 58 9.43946 59 i 9.43990 60 i 9.44034 | L. Cos. L.Tang. 9.42805 9.42856 9.42906 9.42957 9.43007 9.43057 9.43108 9.43158 9.43208 9.43258 9.43308 9.43358 9.43408 9.43458 9.43508 46 46 46 46 46 45 46 46 46 45 46 45 46 45 46 45 45 46 45 45 45 45 45 45 45 44 45 45 45 44 45 44 45 44 45 44 44 44 45 44 44 9.43558 9.43607 9.43657 9.43707 9.43756 9.43806 9.43855 9.43905 9.43954 9.44004 d. c. 9.44053 9.44102 9.44151 9.44201 9.44250 9.44299 9.44348 9.44397 9.44446 9.44495 9.44544 9.44592 9.44641 9.44690 9.44738 9.44787 9.44836 9.44884 9.44933 9.44981 9.45029 9.45078 9.45126 9.45174 9.45222 9.45271 9.45319 9.45367 9.45415 9.45463 51 50 51 50 50 51 50 50 50 50 50 50 50 50 50 49 50 50 49 50 49 50 49 50 49 49 49 50 49 49 49 49 49 49 49 48 49 49 48 49 49 48 49 48 48 49 9.45511 9.45559 9.45606 9.45654 9.45702 9.45750 d. L. Cotg L. Cotg. 1 Li. Cos. d 1157195 9.98494 Q 0.57144 9.98491 * 0.57094 9.98488 6 . 0.57043 9.98484 % 0.56993 9.98481 « 0.56943 9.98477 Q 0.56892 9.98474 % 0.56842 9.98471 « 0.56792 9.98467 4 0.56742 9.98464 ‘ 0.56692 9.98460 f 0.56642 9.98457 * 0.56592 9.98453 ; 0.56542 9.98450 i 0.56492 9.98447 ; 0.56442 9.98443 , 0.56393 9.98440 1 0.56343 9.98436 : 0.56293 9.98433 1 0.56244 9.98429 ; 0.56194 9.98426 0.56145 9.98422 0.56095 9.98419 0.56046 9.98415 0.55996 9.98412 0.55947 9.98409 0.55898 9.98405 0.55849 9.98402 0.55799 9.98398 0.55750 9.98395 0.55701 9.98391 0.55652 9.98388 0.55603 9.98384 0.55554 9.98381 0.55505 9.98377 0.55456 9.98373 0.55408 9.98370 0.55359 9.98366 0.55310 9.98363 0.55262 9.98359 0.55213 9.98356 0.55164 9.98352 0.55116 9.98349 0.55067 9.98345 0.55019 9.98342 0.54971 9.98338 1 0.54922 9.98334 ’ 0.54874 9.98331 ’ 0.54826 9.98327 1 0.54778 9.98324 1 0.54729 9.98320 1 0.54681 9.98317 * 0.54633 9.98313 * 0.54585 , 9.98309 \ 0.54537 9.98306 5 0.54488 > 9.98302 3 0.54441 . 9.98299 7 0.5439-1 t 9.98295 l 0.5434( > 9.98291 5 0.5429* 5 9.98288 8 0.5425( ) 9.98284 c. L.Tang r. L. Sin. 60 59 58 57 56_ 55 54 53 52 51 50 49 48 47 46 45 44 43 42 41 40 39 38 37 36 35 34 33 32 _31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9 d. P. P. 51 50 6 5.1 5.0 7 6.0 5.8 8 6.8 6.7 9 7.7 7.5 10 8.5 8.3 20 17.0 16.7 30 25.5 25.0 40 34.0 33.3 50 42.5 41.7 49 48 6 4.9 4.8 7 5.7 5.6 8 6.5 6.4 9 7.4 7.2 10 8.2 8.0 20 16.3 16.0 30 24.5 24.0 40 32.7 32.0 50 40.8 40.0 47 46 6 4.7 4.a 7 5.5 5.4 8 6.3 6.1 9 7.1 6.9 10 7.8 7.7 20 15.7 15.3 30 23.5 23.0 40 31.3 30.7 50 39.2 38.3 45 4.5 5.3 6.0 6.8 7.5 15.0 22.5 44 4.4 5.1 5.9 6.6 7.8 14.7 22.0 30.0 29.3 37.5 36.7 4 0.4 0.5 0.5 0.6 0.7 1.3 2.0 2.7 3.3 3 0.3 0.4 0.4 0.5 0.5 1.0 1.5 2.0 2.5 P. P. 74 508 LOGARITHMS OF TRIGONOMETRIC FUNCTIONS. 16 ° f L. Sin. d. L.Tang. d. c. L. Cotg. L. Cos. d. P. P 0 9.44034 9.45750 0.54250 9.98284 60 1 9.44078 44 9.45797 47 0.54203 9.98281 3 59 2 9.44122 44 9.45845 48 0.54155 9.98277 4 58 48 A O 3 9.44166 44 9.45892 47 0.54108 9.98273 4 57 47 A *7 4 9.44210 44 43 9.45940 48 47 0.54060 9.98270 3 A 56 6 7 4.8 5.6 4.7 5.5 5 9.44253 9.45987 0.54013 9.98266 4 55 8 6!4 6^3 6 9.44297 44 9.46035 48 0.53965 9.98262 4 54 9 7.2 7.1 7 9.44341 44 9.46082 47 0.53918 9.98259 3 53 10 8.0 7.8 8 9.44385 44 9.46130 48 0.53870 9.98255 4 52 20 16.0 15.7 9 9.44428 43 44 9.46177 47 0.53823 9.98251 4 q 51 30 24.0 23.5 10 9.44472 9.46224 4/ 0.53776 9.98248 o 50 40 32.0 31.3 11 9.44516 44 9.46271 47 0.53729 9.98244 4 49 50 40.0 39.2 12 9.44559 43 9.46319 48 0.53681 9.98240 4 48 13 9.44602 43 9.46366 47 0.53634 9.98237 3 47 14 9.44646 44 AO 9.46413 47 0.53587 9.98233 4 A 46 46 45 15 9.44689 9.46460 4/ 0.53540 9.98229 4 45 6 4.6 4.5 16 9.44733 44 9.46507 47 0.53493 9.98226 3 44 7 5.4 5.3 17 9.44776 43 9.46554 47 0.53446 9.98222 4 43 8 6.1 6.0 18 9.44819 43 9.46601 47 0.53399 9.98218 4 42 9 6.9 6.8 19 9.44862 43 43 9.46648 47 0.53352 9.98215 3 A 41 10 7.7 7.5 20 9.44905 9.46694 40 0.53306 9.98211 4 40 20 15.3 15.0 21 9.44948 43 9.46741 47 0.53259 9.98207 4 39 30 23.0 22.5 22 9.44992 44 9.46788 47 0.53212 9.98204 3 38 40 30.7 30.0 23 9.45035 43 9.46835 47 0.53165 9.98200 4 37 50 38.3 37.5 24 9.45077 42 A Q 9.46881 46 0.53119 9.98196 4 A 36 25 9.45120 9.46928 4/ 0.53072 9.98192 4 35 26 9.45163 43 9.46975 47 0.53025 9.98189 3 34 44 43 27 9.45206 43 9.47021 46 0.52979 9.98185 4 33 6 4.4 4.3 28 9.45249 43 9.47068 47 0.52932 9.98181 4 32 7 5.1 5.0 29 9.45292 43 AO 9.47114 46 An 0.52886 9.98177 4 q 31 8 5.9 5.7 30 9.45334 9.47160 4o 0.52840 9.98174 o 30 9 6.6 *1 O 6.5 31 9.45377 43 9.47207 47 0.52793 9.98170 4 29 10 OA 7.0 -f A hr 7.2 1/IO 32 9.45419 42 9.47253 46 0.52747 9.98166 4 28 20 14.7 14.3 33 9.45462 43 9.47299 46 0.52701 9.98162 4 27 30 22.0 21.5 no 17 34 9.45504 42 9.47346 47 0.52654 9.98159 3 A 26 40 50 29.3 36.7 28.7 35.8 35 9.45547 40 9.47392 40 0.52608 9.98155 4 25 36 9.45589 42 9.47438 46 0.52562 9.98151 4 24 37 9.45632 43 9.47484 46 0.52516 9.98147 4 23 38 9.45674 42 9.47530 46 0.52470 9.98144 3 22 42 41 39 9.45716 42 AO 9.47576 46 A(K 0.52424 9.98140 4 A 21 6 7 4.2 A Q 4.1 A 8 40 9.45758 4Z 9.47622 40 0.52378 9.98136 4 20 g 4.y 5.6 4.0 5.5 41 9.45801 43 9.47668 46 0.52332 9.98132 4 19 9 6.3 6^2 42 9.45843 42 9.47714 46 0.52286 9.98129 3 18 10 7.0 6.8 43 9.45885 42 9.47760 46 0.52240 9.98125 4 17 20 140 13.7 44 9.45927 42 AO 9.47806 46 Ad 0.52194 9.98121 4 A 16 30 2L0 20i5 45 9.45969 4Z 9.47852 40 0.52148 9.98117 15 40 28.0 27.3 46 9.46011 42 9.47897 45 0.52103 9.98113 4 14 50 35.0 34.2 47 9.46053 42 9.47943 46 0.52057 9.98110 3 13 48 9.46095 42 9.47989 46 0.52011 9.98106 4 12 49 9.46136 41 AO 9.48035 46 AK 0.51965 9.98102 4 A 11 4 3 50 9.46178 4Z 9.48080 40 0.51920 9.98098 ‘x 10 6 0.4 0.3 51 9.46220 42 9.48126 46 0.51874 9.98094 4 9 7 0.5 0.4 52 9.46262 42 9.48171 45 0,51829 9.98090 4 8 8 0.5 0.4 53 9.46303 41 9.48217 46 0.51783 9.98087 3 7 9 0.6 0.5 54 9.46345 42 41 9.48262 45 45 0.51738 9.98083 4 4 6 10 0.7 0.5 55 9.46386 9.48307 0.51693 9.98079 5 20 1.3 1.0 56 9.46428 42 8.48353 46 0.51647 9.98075 4 4 30 2.0 1.5 57 9.46469 41 9.48398 45 0.51602 9.98071 4 3 40 2.7 2.0 58 9.46511 42 9.48443 45 0.51557 9.98067 4 2 50 | 3.3 2.5 59 9.46552 41 42 9.48489 46 A*\ 0.51511 9.98063 4 q 1 60 9.46594 9.48534 40 0.51466 9.98060 o 0 L. Cos. d. L. Cotg. d. c. L.Tang. L. Sin. d. f P. P. 73 ° LOGARITHMS OF TRIGONOMETRIC FUNCTIONS. 17 ° 509 ' [j. Sin. d. I ,.Tang. c 0 1 ).46594 ). 46635 41 {148534 9.48579 2 D.46676 41 9.48624 3 3.46717 41 9.48669 4 3.46758 41 42 9.48714 5 6 3.46800 3.46841 41 9.48759 9.48804 7 9.46882 41 9.48849 8 9.46923 41 9.48894 9 9.46964 41 41 9.48939 10 11 9.47005 9.47045 'll 40 9.48984 9.49029 12 9.47086 41 9.49073 13 9.47127 41 9.49118 14 9.47168 41 41 9.49163 15 16 9.47209 9.47249 ‘i-L 40 9.49207 9.49252 17 9.47290 41 9.49296 18 9.47330 40 9.49341 19 9.47371 41 40 9.49385 20 21 9.47411 9.47452 41 9.49430 9.49474 22 9.47492 40 9.49519 23 9.47533 41 9.49563 24 9.47573 40 40 41 9.49607 25 26 9.47613 9.47654 9.49652 9.49696 27 9.47694 40 9.49740 28 9.47734 40 9.49784 29 9.47774 ‘ 40 40 40 9.49828 30 31 9.47814 9.47854 9.49872 9.49916 32 9.47894 40 9.49960 33 34 9.47934 9.47974 40 40 40 40 9.50004 9.50048 35 36 9.48014 9.48054 9.50092 9.50136 37 9.48094 40 9.50180 38 9.48133 39 9.50223 39 9.48173 40 40 39 9.50267 40 41 9.48213 9.48252 9.50311 9.50355 42 9.48292 40 9.50398 43 9.48332 40 9.50442 44 9.48371 39 40 39 9.50485 45 46 9.48411 9.48450 9.50529 9.50572 47 9.48490 40 9.50616 48 9.48529 39 9.50659 49 9.48568 39 39 40 9.50703 50 51 ' 9.48607 9.48647 9.50746 9.50789 52 9.48686 39 9.50833 53 9.48725 39 9.50876 54 9.48764 39 39 9.50919 55 56 9.48803 9.48842 QQ l OU 1 OA 9.50962” 9.51005 57 9.48881 39 9.51048 58 9.4892C 1 9.51092 59 9.4895c ’ 39 9.51135 60 9.4899* » 9.51178 L. Cos . 1 d. L. Cotg d.c. L. Cotg. 45 45 45 45 45 45 45 45 45 45 45 44 45 45 44 45 44 45 44 45 44 45 44 44 45 44 44 44 44 44 44 44 44 44 44 44 44 43 44 44 44 43 44 43 44 43 44 43 44 43 43 44 43 43 43 43 43 44 43 43 0.51466 0.51421 0.51376 0.51331 0.51286 0.51241 0.51196 0.51151 0.51106 0.51061 0.51016 0.50971 0.50927 0.50882 0.50837 0.50793 0.50748 0.50704 0.50659 0.50615 0.50570 0.50526 0.50481 0.50437 0.50393 0.50348 0.50304 0.50260 0.50216 0.50172 0.50128 0.50084 0.50040 0.49996 0.49952 0.49908 0.49864 0.49820 0.49777 0.49733 0.49689 0.49645 0.49602 0.49558 0.49515 0.49471 0.49428 0.49384 0.49341 0.49297 0.49254 0.49211 0.49167 0.49124 0.49081 0.49038 0.48995 0.48952 0.48908 0.48865 0.48822 d. c. IL.Tang Cos. d. .98060 .98056 98052 98048 .98044 98040 98036 .98032 .98029 98025 .98021 98017 9.98013 9.98009 9.98005 9.98001 9.97997 9.97993 9.97989 9.97986 9.97982 9.97978 9.97974 9.97970 9.97966 9.97962 9.97958 9.97954 9.97950 9.97946 9.97942 9.97938 9.97934 9.97930 9.97926 9.97922 9.97918 9.97914 9.97910 9.97906 9.97902 9.97898 9.97894 9.97890 9.97886 9.97882 9.97878 9.97874 9.97870 9.97866 9.97861 9.97857 9.97853 9.97849 9.97845 9.97841 9.97837 9.97833 9.97829 9.97825 9.97821 . L. Sin. d 4 4 3 4 4 4 4 4 4 4 4 4 4 3 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 5 4 4 4 4 4 4 4 4 4 4 60 59 58 57 56 ^ 55 54 53 52 51 50 49 48 47 46 P. P. 45 4.5 5.3 6.0 6.8 7.5 15.0 22.5 30.0 37.5 44 4.4 5.1 5.9 6.6 7.3 14.7 22.0 29.3 36.7 43 4.3 5.0 5.7 6.5 7.2 14.3 21.5 28.7 35.8 42 4.2 4.9 5.6 6.3 7.0 14.0 21.0 28.0 35.0 40 4.0 4.7 5.3 6.0 6.7 13.3 20.0 26.7 33.3 41 4.1 4.8 5.5 6.2 6.8 13.7 20.5 27.3 34.2 39 3.9 4.6 5.2 5.9 6.5 13.0 19.5 26.0 32.5 11 5 4 3 JO 6 0.5 0.4 0.3 9 7 0.6 0.5 0.4 8 8 0.7 0.5 0.4 7 9 0.8 0.6 0.5 6 10 0.8 0.7 0.5 5 ' 20 1.7 1.3 1.0 4 30 2.5 2.0 1.5 40 3.3 2.7 2.0 0 2 1 50 4.2 3.3 2.5 0 t P. P. 72 ° 510 LOGARITHMS OF TRIGONOMETRIC FUNCTIONS. 18 ° / L. Sin. d. L.Tang. d. c. L. Cotg. L. Cos. d. 0 9.48998 9.51178 0.48822 9.97821 60 1 9.49037 39 9.51221 43 0.48779 9.97817 4 59 2 9.49076 39 9.51264 43 0.48736 9.97812 5 58 3 9.49115 39 9.51306 42 0.48694 9.97808 4 57 4 9.49153 38 39 9.51349 43 43 0.48651 9.97804 4 A 56 5 9.49192 9.51392 0.48608 9.97800 4 55 6 9.49231 39 9.51435 43 0.48565 9.97796 4 54 7 9.49269 38 9.51478 43 0.48522 9.97792 4 53 8 9.49308 39 9.515:4) 42 0.48480 9.97788 4 52 9 9.49347 39 38 9.51563 43 43 0.48437 9.97784 4 51 10 9.49385 9.51606 0.48394 9.97779 0 50 11 9.49424 39 9.51648 42 0.48352 9.977“5 4 49 12 9.49462 38 9.51691 43 0.48309 9.97771 4 48 13 9.49500 38 9.51734 43 0.48266 9.97767 4 47 14 9.49539 39 38 9.51776 42 43 0.48224 9.97763 4 A 46 15 9.49577 9.51819 0.48181 9.97759 *± 45 16 9.49615 38 9.51861 42 0.48139 9.97754 5 44 17 9.49654 39 9.51903 42 0.48097 9.97750 4 43 18 9.49692 38 9.51946 43 0.48054 9.97746 4 42 19 9.49730 38 9.51988 42 0.48012 9.97742 4 41 38 A 20 9.49768 9.52031 *±0 0.47969 9.97738 'i 40 21 9.49806 oS 9.52073 42 0.47927 9.97734 4 39 22 9.49844 38 9.52115 42 0.47885 9.97729 5 38 23 9.49882 38 9.52157 42 0.47843 9.97725 4 37 24 9.49920 38 38 9.52200 43 42 0.47800 9.97721 4 A 36 25 9.49958 9.52242 0.47758 9.97717 Tt 35 26 9.49996 38 9.52284 42 0.47716 9.97713 4 34 27 9.50034 38 9.52326 42 0.47674 9.97708 5 33 28 9.50072 38 9.52368 42 0.47632 9.97704 4 32 29 9.50110 38 38 9.52410 42 42 0 47590 9.97700 4 A 31 30 9.50148 9.52452 0.47548 9.97696 rk 30 31 9.50185 37 oo 9.52494 42 0.47506 9.97691 5 29 32 9.50223 38 oo 9.52536 42 0.47464 9.97687 4 28 33 9.50261 38 0*7 9.52578 42 0.47422 9.97683 4 27 34 9.50298 37 38 oo 9.52620 42 41 0.47380 9.97679 4 5 26 35 9.50336 9.52661 0.47339 9.97674 25 36 9.50374 38 9.52703 42 0.47297 9.97670 4 24 37 9.50411 37 oo 9.52745 42 0.47255 9.97666 4 23 38 9.50449 38 0*7 9.52787 42 0.47213 9.97662 4 22 39 9.50486 37 37 OQ 9.52829 42 0.47171 9.97657 5 A 21 40 9.50523 9.52870 “±1 0.47130 9.97653 20 41 9.50561 38 0*7 9.52912 42 0.47088 9.97649 4 19 42 9-50598 37 9.52953 41 0.47047 9.97645 4 18 43 9.50635 37 oo 9.52995 42 0.47005 9.97640 5 17 44 9.50673 38 37 9.53037 42 41 0.46963 9 97636 4 4 16 45 9.50710 0*7 9.53078 0.46922 9.97632 15 46 9.50747 3 / 0*7 9.53120 42 0.46880 9.97628 4 14 47 9.50784 37 9.53161 41 0.46839 9.97623 5 13 48 9.50821 37 0*7 9.53202 41 0.46798 9.97619 4 12 49 9.50858 37 38 9.53244 42 41 0.46756 9.97615 4 11 50 9.50896 0*7 9.53285 0.46715 9.97610 u A 10 51 9.50933 37 0*7 9.53327 42 0.46673 9.97606 4 9 52 9.50970 37 9.53368 41 0.46632 9.97602 4 8 53 9.51007 37 oo 9.53409 41 0.46591 9.97597 5 7 54 9.51043 3b 37 9.53450 41 42 0.46550 9.97593 4 4 6 55 9.51080 9.53492 0.46508 9.97589 5 56 9.51117 37 9.53533 41 0.46467 9.97584 5 4 57 9.51154 37 9.53574 41 0.46426 9.97580 4 3 58 9.51191 37 9.53615 41 0.46385 9.97576 4 2 59 9.51227 36 37 9.53656 41 0.46344 9.97571 5 A 1 60 9.51264 9.53697 0.46303 9.97567 0 L. Cos. d. L. Cotg. d. c. L.Tang. L. Sin. d. / P. P. 43 4.3 5.0 5.7 6.5 7.2 14.3 21.5 28.7 35.8 42 4.2 4.9 5.6 6.3 7.0 14.0 21.0 28.0 35.0 6 7 8 9 10 20 30 40 50 41 4.1 4.8 5.5 6.2 6.8 13.7 20.5 27.3 34.2 6 7 8 9 10 20 30 40 I 50 ! 6 7 8 9 10 20 30 40 50 39 3.9 4.6 5.2 5.9 6.5 13.0 19.5 26.0 32.5 37 3.7 4.3 4.9 5.6 6.2 12.3 18.5 24.7 30.8 5 0.5 0.6 0.7 0.8 0.8 1.7 2.5 3.3 4.2 P. P. 38 3.8 4.4 5.1 5.7 6.3 12.7 19.0 25.3 31.7 36 3.6 4.2 4.8 5.4 6.0 12.0 18.0 24.0 30.0 4 0.4 0.5 0.5 0.6 0.7 1.3 2.0 2.7 3.3 71 ° / 1 ] L. Sin. i 0 < 1 h 2 1 3 ! 4 1 2.51264 , 2.51301 : 2.51338 ; 2.51374 ; 2.51411 5 ' 2.51447 6 1 9.51484 7 9.51520 8 9.51557 9 9.51593 10 9.51629 11 9.51666 12 9.51702 13 9.51738 14 L 9.51774 15 9.51811 16 9.51847 17 9.51883 18 9.51919 19 9.51955 20 9.51991 21 9.52027 22 9.52063 23 9.52099 24 9.52135 25 9.52171 26 9.52207 27 9.52242 28 9.52278 29 9.52314 30 | 9.52350 31 9.52385 32 9.52421 33 9.52456 34 1 9.52492 35 9.52527 36 9.52563 37 9.52598 38 9.52634 39 9.52669 40 9.52705 41 9.52740 42 9.52775 43 9.52811 44 9.52846 45 9.52881 46 9.52916 47 9.52951 48 9.52986 49 9.53021 50 9.53056 51 9.53092 52 9.53126 53 9.53161 54 9.53196 55 9.53231 56 9.53266 57 9.53301 58 9.53336 59 i 9.53370 JO 9.53405 1 L. Cos. LOGARITHMS OF TRIGONOMETRIC FUNCTIONS. 19 ° 511 d. L.Tang. 9.53697 9.53738 9.53779 9.53820 9.53861 37 36 37 36 36 37 36 36 36 37 36 36 36 36 36 36 36 36 36 9.53902 9.53943 9.53984 9.54025 9.54065 9.54106 9.54147 9.54187 9.54228 9.54269 36 35 36 36 36 35 36 35 36 35 36 35 36 35 36 35 35 36 35 35 35 35 35 35 35 36 34 35 35 35 35 35 35 34 35 d. c. 9.54309 9.54350 9.54390 9.54431 9.5 4471 9.54512 9.54552 9.54593 9.54633 9.54673 9.54714 9.54754 9.54794 9.54835 9.54875 9.54915 9.54955 9.54995 9.55035 9.55075 9.55115 9.55155 9.55195 9 55235 9.55275 9.55315 9.55355 9.55395 9.55434 9.55474 9.55514 9.55554 9.55593 9.55633 9.55673 9.55712 9.55752 9.55791 9.55831 9.55870 9.55910 9.55949 9.55989 9.56028 9.56067 9.56107 41 41 41 41 41 41 41 41 40 41 41 40 41 41 40 41 40 41 40 41 40 41 40 40 41 40 40 41 40 40 40 40 40 40 40 40 40 40 40 40 40 40 39 40 40 40 39 40 40 39 40 39 40 39 40 39 40 39 39 40 d. L. Cotg.l d. c. j. Cotg. : L. Cos. d. I 0.46303 9.97567 50 0.46262 9.97563 4 E 59 0.46221 9.97558 5 58 0.46180 9.97554 4 57 5 0.46139 9.97550 4 5 56 7 0.46098 9.97545 A 55 8 0.46057 9.97541 4 54 9 0.46016 9.97536 5 A 53 10 0.45975 9.97532 4 52 20 •1 0.45935 9.97528 4 5 51 30 ( 0.45894 9.97523 50 40 0.45853 9.97519 4 49 50 0.45813 9.97515 4 E 48 0.45772 9 97510 0 A 47 0.45731 9.97506 4 5 - 46 0.45691 9.97501 V A '45 ( 0.45650 9.97497 4 44 0.45610 9.97492 5 43 i 0.45569 9.97488 4 42 < 0.45529 9.97484 4 41 li "0.45488 9.97479 o A 40 2 < 0.45448 9.97475 4 39 o' At 0.45407 9.97470 5 38 4 1 E, 0.45367 9.97466 4 E 37 O 1 0.45327 9.97461 0 4 36 0.45286 9.97457 35 0.45246 9.97453 4 34 0.45206 9.97448 5 33 6 0.45165 9.97444 4 E 32 7 0.45125 9.97439 0 4 31 8 Q 1 0.45085 9.97435 E 30 10 0.45045 9.97430 O A 29 20 0.45005 9.97426 4 E 28 30 0.44965 9.97421 0 A 27 40 0.44925 9.97417 4 5 26 50 044885 9.97412 A 25 0.44845 9.97408 4 E 24 0.44805 9.97403 0 A 23 0.44765 9.97399 4 c 22 a 0.44725 9.97394 O 4 21 u 7 0.44685 9.97390 20 8 0.44645 9.97385 0 A 19 9 0.44605 9.97381 4 E 18 10 0.44566 9.97376 o A 17 20 0.44526 9.97372 4 5 16 30 0.44486 9.97367" A 15" 40 0.44446 9.97363 4 E 14 50 0.44407 9.97358 0 E 13 0.44367 9.97353 0 12 0.44327 9.97349 4 5 11 0.44288 9.97344 '0 6 0.44248 9.97340 ; i 9 *3 0.44209 i 9.97335 • l 8 * 0.44169 i 9.97331 4 7 c 0.44130 l 9.97326 L t 6 1C 0.4409C 1 9.97322 5 2 ( 0.44051 . 9.9731*3 r 0 4 OK At 0.44011 l 9.97312 > 5 3 41 0.43971 > 9.9730* S \ 2 Ol 0.4393* 5 9.9730* \ l 1 0.4389* 5 9.97295 0 i. L.Tani I L. Sin . d. / P. P. 41 4.1 4.8 5.5 6.2 6.8 40 4.0 4.7 5.3 6.0 6.7 13.3 20.0 26.7 33.3 39 3.9 4.6 5.2 5.9 6.5 13.0 19.5 26.0 32.5 37 3.7 4.3 4.9 5.6 6.2 12.3 18.5 24.7 30.8 35 3.5 4.1 4.7 5.3 5.8 11.7 17.5 23.3 29.2 0.6 0.7 0.8 0.8 1.7 2.5 3.3 4.2 36 3.6 4.2 4.8 5.4 6.0 12.0 18.0 24.0 30.0 34 3.4 4.0 4.5 5.1 5.7 11.3 17.0 22.7 28.3 4 0.4 0.5 0.5 0.6 0.7 1.3 2.0 2.7 3.3 P. P. 70 ° 512 LOGARITHMS OF TRIGONOMETRIC FUNCTIONS. 20 ° / L. Sin. 0 9.53405 1 9.53440 2 9.53475 3 9.53509 4 9.53544 5 9.53578 6 9.53613 7 9.53647 8 9.53682 9 9.53716 10 9.53751 11 9.53785 12 9.53819 13 9.53854 14 9.53888 15 9.53922 16 9.53957 17 9.53991 18 9.54025 19 9.54059 20 9.54093 21 9 54127 22 9.54161 23 9.54195 24 9.54229 25 9.54263 26 9.54297 27 9.54331 28 9.54365 29 9.54399 30 9.54433 31 9.54466 32 9.54500 33 9.54534 34 9.54567 35 9.54601 36 9.54635 37 9.54668 38 9.54702 39 9.54735 40 9.54769 41 9.54802 42 9.54836 43 9.54869 44 9.54903 45 9.54936 46 9.54969 47 9.55003 48 9.55036 49 9.55069 50 9.55102 51 9.55136 52 9.55169 53 9.55202 54 9.55235 55 9.55268 56 9.55301 57 9.55334 58 9.55367 59 9.55400 60 9.55433 L. Cos. d. 35 35 34 35 34 35 34 35 34 35 34 34 35 34 34 35 34 34 34 34 34 34 34 34 34 34 34 34 34 34 33 34 34 33 34 34 33 34 33 34 33 34 33 34 33 33 34 33 33 33 34 33 33 33 33 33 33 33 33 33 L.Tang. 9.56107 9.56146 9.56185 9.56224 9.56264 9.56303 9.56342 9.56381 9.56420 9.56459 9.56498 9.56537 9.56576 9.56615 9.56654 9.56693 9.56732 9.56771 9.56810 9.56849 9.56887 9.56926 9.56965 9.57004 9.57042 9.57081 9.57120 9.57158 9.57197 9.57235 9.57274 9.57312 9.57351 9.57389 9.57428 9.57466 9.57504 9.57543 9.57581 9.57619 9.57658 9.57696 9.57734 9.57772 9.57810 9.57849 9.57887 9.57925 9.57963 9.58001 9.58039 9.58077 9.58115 9.58153 9.58191 9.58229 9.58267 9.58304 9.58342 9.58380 9.58418 d. L. Cotg, d. c. 39 39 39 40 39 39 39 39 39 39 39 39 39 39 39 39 39 39 39 38 39 39 39 38 39 39 38 39 38 39 38 39 38 39 38 38 39 38 38 39 38 38 38 38 39 38 38 38 38 38 38 38 38 38 38 38 37 38 38 38 L. Cotg. L. Cos. d. P. P. 0.43893 9.97299 60 0.43854 9.97294 5 59 0.43815 9.97289 5 58 0.43776 9.97285 4 57 4U 39 0.43736 9.97280 5 A 56 6 7 4.0 4.7 3.9 4.6 0.43697 9.97276 ‘i. 55 8 5.3 5.2, 0.43658 9.97271 5 54 9 6.0 5.9 0.43619 9.97266 5 53 10 6.7 6.5 0.43580 9.97262 4 52 20 13.3 13.0 0.43541 9.97257 5 51 30 ! 20.0 19.5 0.43502 9.97252 0 50 40 26.7 26.0 0.43463 9.97248 4 49 50 1 33.3 32.5 0.43424 9.97243 5 48 0.43385 9.97238 5 47 0.43346 9.97234 4 46 38 37 0.43307 9.97229 o 45 6 3.8 3.7 0.43268 9.97224 5 44 7 4.4 4.3 0.43229 9.97220 4 43 8 5.1 4.9 0.43190 9.97215 c 42 9 5.7 5.6 0.43151 9.97210 5 A 41 10 6.3 6.2 0.43113 9.97206 ‘i 40 20 12.7 12.3 0.43074 9.97201 5 39 30 19.0 18.5 0.43035 9.97196 5 38 40 25.3 24.7 0.42996 9.97192 4 37 50 31.7 30.8 0.42958 9.97187 5 36 0.42919 9.97182 O 35 0.42880 9.97178 4 34 35 0.42842 9.97173 5 33 6 3.5 0.42803 9.97168 5 32 7 4.1 0.42765 9.97163 5 A 31 8 4.7 0.42726 9.97159 30 y in 5.3 p; Q 0.42688 9.97154 5 29 on O.o ii 7 0.42649 9.97149 5 28 ZU on 11. / ir c 0.42611 9.97145 4 27 30 An 1/.0 OQ Q 0.42572 9.97140 5 F» 26 Z6.6 9Q 9 0.42534 9.97135 o 25 0.42496 9.97130 5 24 0.42457 9.97126 4 23 0.42419 9.9712] 5 22 34 33 0.42381 9.97116 5 r 21 6 7 3.4 4 0 3.3 q Q 0.42342 9.97111 o 20 i 8 4.5 4.4 0.42304 9.97107 4 19 9 5.1 5.0 0.42266 9.97102 5 18 10 5.7 5.5 0.42228 9.97097 5 17 20 11.3 11.0 0.42190 9.97092 5 K 16 30 17.0 16.5 0.42151 9.97087 0 15 40 22.7 22.0 0.42113 9.97083 4 14 50 28.3 27.5 0.42075 9.97078 5 13 0.42037 9.97073 5 12 0.41999 9.97068 5 k 11 5 4 0.41961 9.97063 o A 10 6 0.5 0.4 0.41923 9.97059 4 9 7 0.6 0.5 0.41885 9.97054 5 8 8 0.7 0.5 0.41847 9.97049 5 7 9 0.8 0.6 0.41809 9.97044 5 f; 6 10 0.8 0.7 0.41771 9.97039 o 5 20 1.7 1.3 0.41733 9.97035 4 4 30 2.5 2.0 0.41696 9.97030 5 3 40 3.3 2.7 0.41658 9.97025 5 2 50 4.2 3.3 0.41620 9.97020 5 1 0.41582 9.97015 o 0 L.Tang. L. Sin. d. / P. P. LOGARITHMS OF TRIGONOMETRIC FUNCTIONS. 21 ° 513 / L. Sin. 0 1 3.55433 1 1 3.55466 2 ! 9.55499 3 ( 9.55532 4 ! 9.55564 5 1 9.55597 6 9.55630 7 9.55663 8 9.55695 9 9.55728 10 9.55761 11 9.55793 12 9.55826 13 9.55858 14 9.55891 15 9.55923 16 9.55956 17 9.55988 18 9.56021 19 9.56053 20 9.56085 21 9.56118 22 9.56150 23 9.56182 24 9.56215 25 9.56247 26 9.56279 27 9.56311 28 9.56343 29 9.56375 30 9.56408 31 9.56440 32 9.56472 33 9.56504 34 9.56536 35 9.56568 36 9.56599 37 9.56631 38 9.56663 39 9.56695 40 9.56727 41 9.56759 42 9.56790 43 9.56822 44 9.56854 45 9.56886 46 9.56917 47 9.56949 48 9.56980 49 9.57012 50 9.57044 51 9.57075 52 9.57107 53 9.57138 54 9.57169 55 ‘ 9.57201 56 9.57232 57 9.57264 58 9.57295 59 9.57326 60 9.57358 L. Cos. 33 33 33 32 33 33 33 32 33 33 32 33 32 33 32 33 32 33 32 32 33 32 32 33 32 32 32 32 32 33 32 32 32 32 32 31 32 32 32 32 32 31 32 32 32 31 32 31 32 32 31 32 31 31 32 31 32 31 31 32 If. .Tang. d.c. I j. Cotg. L. Cos. d. 158418 158455 >.58493 158531 >.58569 37 38 38 38 Q7 0.41582 0.41545 0.41507 0.41469 0.41431 9.97015 9.97010 9.97005 9.97001 9.96996 5 5 4 5 5 60 59 58 57 56 >.58606 61 0.41394 9.96991 55 >.58644 38 0.41356 9.96986 5 54 >.58681 37 0.41319 9.96981 5 53 >.58719 38 0.41281 9.96976 5 52 >.58757 38 Q7 0.41243 9.96971 5 5 51 >.58794 61 0.41206 9.96966 A 1 50 >.58832 38 0.41168 9.96962 4 49 9.58869 37 0.41131 9.96957 5 E 48 9.58907 38 0.41093 9.96952 0 r 47 3.58944 37 07 0.41056 9.96947 5 5 46 9.58981 6/ 0.41019 9.96942 e 45 9.59019 38 0.40981 9.96937 0 e 44 9.59056 37 0.40944 9.96932 0 E 43 9.59094 38 0.40906 9.96927 O e 42 9.59131 37 Q7 0.40869 9.96922 . 5 1 5 41 9.59168 61 0.40832 9.96917 e 40 9.59205 37 0.40795 9.96912 0 e 39 9.59243 38 0.40757 9.96907 0 A 38 9.59280 37 0.40720 9.96903 4 E 37 9.59317 37 07 0.40683 9.96898 5 5 36 9.59354 Oi 0.40646 9.96893 e 35 9.59391 37 0.40609 9.96888 O E 34 9.59429 38 0.40571 9.96883 5 e 33 9.59466 37 0.40534 9.96878 O E 32 9.59503 37 07 0.40497 9.96873 0 5 31 9.59540 61 0.40460 9.96868 c 30 9.59577 37 0.40423 9.96863 0 E 29 9.59614 37 0.40386 9.96858 0 E 28 9.59651 37 0.40349 9.96853 D E 27 9.59688 37 Q7 0.40312 9.96848 0 5 26 9.59725 04. 0.40275 9.96843 E 25 9.59762 37 0.40238 9.96838 0 E 24 9.59799 37 0.40201 9.96833 0 E 23 9.59835 36 0.40165 9.96828 0 E 22 9.59872 37 Q7 0.40128 9.96823 0 5 21 9.59909 04 0.40091 9.96818 E 20 9.59946 37 0.40054 9.96813 0 E 19 9.59983 37 0.40017 9.96808 0 E 18 9.60019 36 0.39981 9.96803 0 E 17 9.60056 37 37 0.39944 9.96798 0 5 16 9.60093 0.39907 9.96793 E 15 9.60130 37 0.39870 9.96788 0 E 14 9.60166 36 0.39834 9.96783 0 E 13 9.60203 37 0.39797 9.96778 0 a 12 9.60240 37 oa 0.39760 9.96772 D - 5 11 9.60276 DO 0.39724 9.96767 E 10 9.60313 37 0.39687 9.96762 0 E 9 9.60349 36 0.39651 9.96757 0 E 8 9.60386 37 0.39614 9.96752 D E 7 9.60422 36 *37 0.39578 9.96747 0 5 6 9.60459 oi 0.39541 9.96742 5 9.60495 gg 0.39505 9.96737 5 4 9.60532 i 37 0.39468 ; 9.96732 > 5 3 9.60568 l jj® 0.39432 : 9.96727 ’ 5 2 9.60605 ' 36 0.39395 > 9.96722 ! ^ r & 1 9.60641 0.3935? > 9.96717 0 L. Cotg d. c. , L.Tang ;. L. Sin, . d. / P. P. 38 3.8 4.4 5.1 5.7 6.3 12.7 19.0 25.3 31.7 38 3.6 4.2 4.8 5.4 6.0 12.0 18.0 24.0 30.0 37 3.7 4.3 4.9 5.6 6.2 12.3 18.5 24.7 30.8 33 3.3 3.9 4.4 5.0 5.5 11.0 16.5 22.0 27.5 6 7 8 9 10 20 30 40 50 32 3.2 3.7 4.3 4.8 5.3 10.7 16.0 21.3 26.7 6 7 8 9 10 20 30 40 50 31 3.1 3.6 4.1 4.7 5.2 10.3 15.5 20.7 25.8 6 7 8 9 10 20 30 40 50 5 0.5 0.6 0.7 0.8 0.8 1.7 2.5 3.3 4.2 6 0.6 0.7 0.8 0.9 1.0 2.0 3.0 4.0 5.0 4 0.4 0.5 0.5 0.6 0.7 1.3 2.0 2.7 3.3 P. P. lO 514 LOGARITHMS OF TRIGONOMETRIC FUNCTIONS. 22 ° r L. Sin. d. L.Tang. d. c. L. Cotg. L. Cos. d. P . P. 0 9.57358 9.60641 0.39359 9.96717 60 1 9.57389 31 9.60677 36 0.39323 9.96711 6 59 2 9.57420 31 9.60714 37 0.39286 9.96706 5 58 3 9.57451 31 9.60750 36 0.39250 9.96701 5 57 ct a/ O *7 36 4 9.57482 31 QO 9.60786 36 37 0.39214 9.96696 5 56 D 7 3.7 4.3 3.6 4.2 5 9.57514 9.60823 0.39177 9.96691 o '55 8 4!9 4^8 6 9.57545 31 9.60859 36 0.39141 9.96686 5 54 9 5.6 5.4 7 9.57576 31 9.60895 36 0.39105 9.96681 5 53 10 6.2 6.0 . 8 9.57607 31 9.60931 36 0.39069 9.96676 5 52 20 12.3 12.0 9 9.57638 31 9.60967 36 37 0.39033 9.96670 6 51 30 18.5 18.0 10 9.57669 9.61004 0.38996 9.96665 O 50 40 24.7 24.0 11 9.57700 31 9.61040 36 0.38960 9.96660 5 49 50 30.8 30.0 12 9.57731 31 9.61076 36 0.38924 9.96655 5 48 13 9.57762 31 9.61112 36 0.38888 9.96650 5 47 14 9.57793 31 q-i 9.61148 36 36 0.38852 9.96645 5 46 35 15 9.57824 9.61184 0.38816 9.96640 0 45 6 3.5 16 9.57855 31 9.61220 36 0.38780 9.96634 6 44 7 4.1 17 9.57885 30 9.61256 36 0.38744 9.96629 5 43 8 4.7 18 9.57916 31 9.61292 36 0.38708 9.96624 5 42 9 5.3 19 9.57947 31 9.61328 36 36 0.38672 9.96619 5 41 10 5.8 20 9.57978 o± 9.61364 0.38636 9.96614 0 40 20 11.7 21 9.58008 30 9.61400 36 0.38600 9.96608 6 39 30 17 .5 22 9.58039 31 9.61436 36 0.38564 9.96603 5 38 40 23.3 23 9.58070 31 9.61472 36 0.38528 9.96598 5 37 50 29.2 24 9.58101 31 9.61508 36 36 0.38492 9.96593 5 36 25 9.58131 9.61544 0.38456 9.96588 0 35 26 9.58162 31 9.61579 35 0.38421 9.96582 6 34 32 31 27 9.58192 30 9.61615 36 0.38385 9.96577 5 33 6 3.2 3.1 28 9.58223 31 9.61651 36 0.38349 9.96572 5 32 7 3.7 3.6 29 9.58253 30 31 9.61687 36 35 0.38313 9.96567 5 31 8 4.3 4.1 30 9.58284 9.61722 0.38278 9.96562 o 30 9 1 A 4.8 K Q 4.7 K O 31 9.58314 30 9.61758 36 0.38242 9.96556 6 29 1U on O.o in *7 O.Z in q 32 9.58345 31 9.61794 36 0.38206 9.96551 5 28 ZU on 1U. / i c* n 1 KJ.O ICC 33 9.58375 30 9.61830 36 0.38170 9.96546 5 27 oU An Lo.U Ol Q 10. 0 on h 34 9.58406 31 30 9.61865 35 36 0.38135 9.96541 5 a 26 50 Zl.o 9fi.7 Zkj. / 25.8 35 9.58436 9.61901 0.38099 9.96535 0 25 36 9.58467 31 9.61936 . 35 0.38064 9.96530 5 24 37 9.58497 30 9.61972 36 0.38028 9.96525 5 23 38 9.58527 30 9.62008 36 0.37992 9.96520 5 22 ou 29 39 9.58557 30 31 9.62043 35 36 0.37957 9.96514 6 21 6 7 3.0 q f; 2.9 Q 1 40 9.58588 9.62079 0.37921 9.96509 o 20 i 3 0.0 4.0 O.i 3.9 41 9.58618 30 9.62114 35 0.37886 9.96504 5 19 9 4/5 4/4 42 9.58648 30 9.62150 36 0.37850 9.96498 6 18 10 5^0 4*8 43 9.58678 30 9.62185 35 0.37815 9.96493 5 17 20 io!o 9^7 44 9.58709 31 30 9.62221 36 35 0.37779 9.96488 5 K 16 30 15!o 14.5 45 9.58739 9.62256 0.37744 9.96483 o 15 40 20.0 19.3 46 9.58769 30 9.62292 36 0.37708 9.96477 6 14 50 25.0 24.2 47 9.58799 30 9.62327 35 0.37673 9.96472 5 13 48 9.58829 30 9.62362 35 0.37638 9.96467 5 12 49 9.58859 30 30 9.62398 36 35 0.37602 9.96461 6 11 fi 5 50 9.58889 9.62433 0.37567 9.96456 o 10 6 0.6 0.5 51 9.58919 30 9.62468 35 0.37532 9.96451 5 9 7 0.7 0.6 52 9.58949 30 9.62504 3 6 l 0.37496 9.96445 6 8 8 0.8 0.7 53 9.58979 30 9.62539 35 0.37461 9.96440 5 7 9 0.9 0.8 54 9.59009 30 30 9.62574 35 35 0.37426 9.96435 5 6 6 10 1.0 0.8 55 9.59039 9.62609 0.37391 9.96429 5 20 2.0 1.7 56 9.59069 30 9.62645 36 0.37355 9.96424 5 4 30 3.0 2.5 57 9.59098 29 9.62680 35 0.37320 9.96419 5 3 40 4.0 3.3 58 9.59128 30 9.62715 35 0.37285 9.96413 6 2 50 5.0 4.2 59 9.59158 30 30 9.62750 35 35 0.37250 9.96408 5 * 1 60 9.59188 9.62785 0.37215 9.96403 O 0 L. Cos. d. L. Cotg. d. c. L.Tang. L. Sin. d. t P. P. 67 ° LOGARITHMS OF TRIGONOMETRIC FUNCTIONS. 23 ° 515 t L. Sin.^ 0 9.59188 1 9.59218 2 9.59247 3 9.59277 4 9.59307 5 9.59336 6 9.59366 7 9.59396 8 9.59425 9 9.59455 10 9.59484 11 9.59514 12 9.59543 13 9.59573 14 9.59602 15 9.59632 16 9.59661 17 9.59690 18 9.59720 19 9.59749 20 9.59778 21 9.59808 22 9.59837 23 9.59866 24 9.59895 25 9.59924 26 9.59954 27 9.59983 28 9.60012 29 9.60041 30 9.60070 31 9.60099 32 9.60128 33 9.60157 34 9.60186 35 9.60215 36 9.60244 37 9.60273 38 9.60302 39 9.60331 40 9.60359 41 9.60388 42 9.60417 43 9.60446 44 9.60474 45 *9.60503 46 9.60532 47 9.60561 48 9.60589 49 9.60618 50 9.60646 51 9.60675 52 9.60704 53 9.60732 54 9.60761 55 9.60789 56 9.60818 57 9.60846 58 9.60875 59 9.60903 60 9.60931 L. Cos. L. Cotg. L. Cos. d. 0.37215 9.96403 60 0.37180 9.96397 6 59 0.37145 9.96392 5 58 0.37110 9.96387 5 57 0.37074 9.96381 6 f; 56 0.37039 9.96376 u 55 0.37004 9.96370 6 54 0.36969 9.96365 5 53 0.36934 9.96360 5 52 0.36899 9.96354 6 5 51 0.36865 9.96349 50 0.36830 9.96343 6 49 0.36795 9.96338 5 48 0.36760 9.96333 5 47 0.36725 9.96327 6 46 0.36690 9.96322 o 6 45 0.36655 9.96316 44 0.36621 9.96311 5 43 0.36586 9.96305 6 42 0.36551 9.96300 5 6 41 0.36516 9.96294 40 0.36481 9.96289 5 39 0.36447 9.96284 5 38 0.36412 9.96278 6 37 0.36377 9.96273 5 6 36 0.36343 9.96267 35 0.36308 9.96262 5 34 0.36274 9.96256 6 33 0.36239 9.96251 5 32 0.36204 9.96245 6 5 31 0.36170 9.9624C 30 0.36135 9.96234 6 29 0.36101 9.96229 5 28 0.36066 9.96223 6 27 0.36032 9.96218 5 6 26 0.35997 9.96212 25 0.35963 9.96207 5 24 0.35928 9.96201 6 23 0.35894 9.96196 5 22 0.35860 9.96190 6 5 21 0.35825 9.96185 20 0.35791 9.96179 6 19 0.35757 9.96174 5 18 0.35722 9.96168 6 17 0.35688 9.96162 6 5 16 0.35654 9.96157 15 0.35619 9.96151 6 14 0.35585 9.96146 5 6 13 0.35551 9.96140 12 0.35517 9.96135 5 6 11 0.35483 9.96129 10 0.35448 9.96123 6 9 0.35414 9.96118 5 8 0.35380 9.96112 6 7 0.35346 9.96107 5 6 6 0.35312 9.96101 5 0.35278 9.96095 6 4 0.35244 9.96090 5 3 0.35210 9.96084 6 2 0.35176 9.96079 5 6 1 0.35142 9.96073 0 L.Tang. L. Sin. d. t d. L.Tang. 30 29 30 30 29 30 30 29 30 29 30 29 30 29 30 29 29 30 29 29 30 29 29 29 29 30 29 29 29 29 29 29 29 29 29 29 29 29 29 28 29 29 29 28 29 29 29 28 29 28 29 29 28 29 28 29 28 29 28 28 9.62785 9.62820 9.62855 9.62890 9.62926 9.62961 9.62996 9.63031 9.63066 9.63101 9.63135 9.63170 9.63205 9.63240 9.63275 9.63310 9.63345 9.63379 9.63414 9.63449 9.63484 9.63519 9.63553 9.63588 9.63623 9.63657 9.63692 9.63726 9.63761 9.63796 9.63830 9.63865 9.63899 9.63934 9.63968 d. c. 9.64003 9.64037 9.64072 9.64106 9.64140 9.64175 9.64209 9.64243 9.64278 9.64312 9.64346 9.64381 9.64415 9.64449 9.64483 9.64517 9.64552 9.64586 9.64620 9.64654 1164688 9.64722 9.64756 9.64790 9.64824 9164858 d. L. Cotg 35 35 35 36 35 35 35 35 35 34 35 35 35 35 35 35 34 35 35 35 35 34 35 35 34 35 34 35 35 34 35 34 35 34 35 34 35 34 34 35 34 34 35 34 34 35 34 34 34 34 35 34 34 34 34 34 34 34 34 34 d. c. P. P. 36 3.6 4.2 4.8 5.4 6.0 12.0 18.0 24.0 30.0 35 3.5 4.1 4.7 5.3 5.8- 11.7* 17.5 23.3 29.2 6 7 8 9 10 20 30 40 50 34 3.4 4.0 4.5 5.1 5.7 11.3 17.0 22.7 28.3 30 3.0 3.5 4.0 4.5 5.0 10.0 15.0 20.0 25.0 29 2.9 3.4 3.9 •4.4 4.8 9.7 14.5 19.3 24.2 6 7 8 9 10 20 30 40 50 28 2.8 3.3 3.7 4.2 4.7 9.3 14.0 18.7 23.3 6 7 8 9 10 .20 30 40 50 6 0.6 0.7 0.8 0.9 1.0 2.0 3.0 4.0 5.0 5 0.5 0.6 0.7 0.8 0.8 1.7 2.5 3.3 4.2 P. P. 66 516 LOGARITHMS OF TRIGONOMETRIC FUNCTIONS. 24 ° f L. Sin. d. L.Tang. d. c. ] L. Cotg. L. Cos. 0 1 9.60931 9.60960 29 9.64858 9.64892 34 0.35142 0.35108 9.96073 9.96067 2 9.60988 28 9.64926 34 0.35074 9.96062 3 9.61016 28 9.64960 34 0.35040 9.96056 4 9.61045 29 28 28 9.64994 34 34 - 34 0.35006 9.96050 5 6 9.61073 9.61101 9.65028 9.65062 0.34972 0.34938 9.96045 9.96039 7 9.61129 28 9.65096 34 0.34904 9.96034 8 9.61158 29 9.65130 34 0.34870 9.96028 9 9.61186 28 28 28 9.65164 34 33 34 0.34836 9.96022 10 11 9.61214 9.61242 9.65197 9.65231 0.34803 0.34769 9.96017 9.96011 12 9.61270 28 9.65265 34 0.34735 9.96005 13 9.61298 28 9.65299 34 0.34701 9.96000 14 9.61326 28 28 28 9.65333 34 qq 0.34667 9.95994 15 16 9.61354 9.61382 9.65366 9.65400 OO 34 0.34634 0.34600 9.95988 9.95982 17 9.61411 29 9.65434 34 0.34566 9.95977 18 9.61438 27 9.65467 33 0.34533 9.95971 19 9.61466 28 28 28 9.65501 34 04 . 0.34499 9.95965 20 21 9.61494 9.61522 9.65535 9.65568 cyi 33 0.34465 0.34432 9.95960 9.95954 22 9.61550 28 9.65602 34 0.34398 9.95948 23 9.61578 28. 9.65636 34 0.34364 9.95942 24 9.61606 28 28 28 9.65669 33 °A 0.34331 9.95937 25 26 9.61634 9.61662 9.65703 9.65736 irt 33 0.34297 0.34264 9.95931 9.95925 27 9.61689 27 9.65770 34 0.34230 9.95920 28 9.61717 28 9.65803 33 0.34197 9.95914 29, 9.61745 28 28 27 9.65837 34 QQ 0.34163 9.95908 30 31 9.61773 9.61800 9.65870 9.65904 Ot) 34 0.34130 0.34096 9.95902 9.95897 32 9.61828 28 9.65937 33 0.34063 9.95891 33 9.61856 28 9.65971 34 0.34029 9.95885 34 9.61883 27 28 28 9.66004 33 0.33996 9.95879 35 36 9.61911 9.61939 9.66038 9.66071 33 0.33962 0.33929 9.95873 9.95868 37 9.61966 27 9.66104 33 0.33896 9.95862 38 9.61994 28 9.66138 34 0.33862 9.95856 39 9.62021 27 28 27 9.66171 33 0.33829 9.95850 40 41 1162049 9.62076 9.66204 9.66238 OO 34 0.33796 0.33762 9.95844 9.95839 42 9.62104 28 9.66271 33 0.33729 9.95833 43 9.62131 27 9.66304 33 0.33696 9.95827 44 9.62159 28 27 28 9.66337 33 34 33 0.33663 9.95821 45 46 9.62186 9.62214 9.66371 9.66404 0.33629 0.33596 9.95815 9.95810 47 9.62241 27 9.66437 33 0.33563 9.95804 48 9.62268 27 9.66470 33 0.33530 9.95798 49 9.62296 28 27 27 9.66503 33 34 33 0.33497 9.95792 50 51 9.62323 9.62350 9.66537 9.66570 0.33463 0.33430 9.95786 9.95780 52 9.62377 27 9.66603 33 0.33397 9.95775 53 9.62405 28 9.66636 33 0.33364 9.95769 54 9.62432 27 27 9.66669 33 33 0.33331 9.95763 55 9.62459 9.66702 0.33298 9.95757 56 9.62486 27 9.66735 33 0.33265 9.95751 57 9.62513 27 9.66768 33 0.33232 9.95745 58 9.62541 28 9.66801 33 0.33199 9.95739 59 9.62568 27 07 9.66834 33 QQ 0.33166 9.95733 60 ' 9.62595 9.66867 OO 0.33133 9.95728 L. Cos. d. L. Cotg . d. c. L.Tang . L. Sin. d. 6 5 6 6 5 6 5 6 6 5 6 6 5 6 6 6 5 6 6 5 6 6 6 5 6 6 5 6 6 6 5 6 6 6 6 5 6 6 6 6 5 6 6 6 6 5 6 6 6 6 6 5 6 6 6 6 6 6 6 5 ~dT 45 44 43 42 41 40 39 38 37 36 35 34 33 32 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 to 9 8 7 _6 5 4 3 2 1 P. P. 34 3.4 4.0 4.5 5.1 5.7 11.3 17.0 22.7 28.3 33 3.3 3.9 4.4 5.0 5.5 11.0 16.5 22.0 27.5 6 7 8 9 10 20 30 40 50 6 7 8 9 10 20 30 40 50 6 7 8 9 10 20 30 40 50 29 2.9 3.4 3.9 4.4 4.8 9.7 14.5 19.3 24.2 28 2.8 3.3 3.7 4.2 4.7 9.3 14.0 18.7 23.3 27 2.7 3.2 3.6 4.1 4.5 9.0 13.5 18.0 22.5 7 8 9 10 20 30 40 50 6 0.6 0.7 0.8 0.9 1.0 2.0 3.0 4.0 5.0 5 0.5 0.6 0.7 0.8 0.8 1.7 2.5 3.3 4-2 P. P. 65 ° LOGARITHMS OF TRIGONOMETRIC FUNCTIONS . 25 ° 517 / L. Sin. 0 9.62595 1 9.62622 2 9.62649 3 9.62676 4 9.62703 5 9.62730 6 9.62757 7 9.62784 8 9.62811 9 9.62838 10 '9.62865 11 9.62892 12 9.62918 13 9.62945 14 9.62972 15 9.62999 16 9.63026 17 9.63052 18 9.63079 19 9.63106 20 9.63133 21 9.63159 22 9.63186 23 9.63213 24 9.63239 25 9.63266 26 9.63292 27 9.63319 28 9.63345 29 9.63372 30 9.63398 31 9.63425 32 9.63451 33 9.63478 34 9.63504 35 9.63531 36 9.63557 37 9.63583 38 9.63610 39 9.63636 40 9.63662 41 9.63689 42 9.63715 43 9.63741 44 9.63767 45 9.63794 46 9.63820 47 9.63846 48 9.63872 49 9.63898 50 9.63924 51 9.63950 52 9.63976 53 9.64002 54 9.64028 55 9.64054 56 9.64080 57 9.64106 58 9.64132 59 9.64158 60 9.64184 L. Cos. d. 27 27 . 27 27 27 27 27 27 27 27 27 26 27 27 27 27 26 27 27 27 26 27 27 26 27 26 27 26 27 26 27 26 27 26 27 26 26 27 26 26 27 26 26 26 27 26 26 26 26 26 26 26 26 26 26 26 26 26 26 26 L.Tang. d. c. |L. Cotg. 9.66867 9.66900 9.66933 9.66966 9.66999 9.67032 9.67065 9.67098 9.67131 9.67163 9.67196 9.67229 9.67262 9.67295 9.67327 9.67360 9.67393 9.67426 9.67458 9.67491 9.67524 9.67556 9.67589 9.67622 9.67654 d. 9.67687 9.67719 9.67752 9.67785 9.67817 9.67850 9.67882 9.67915 9.67947 9.67980 9.68012 9.68044 9.68077 9.68109 9.68142 9.68174 9.68206 9.68239 9.68271 9.68303 9.68336 9.68368 9.68400 9.68432 9.68465 9.68497 9.68529 9.68561 9.68593 9.68626 9.68658 9.68690 9.68722 9.68754 9.68786 9.68818 L. Cotg. 33 33 33 33 33 33 33 33 32 33 33 33 33 32 33 33 33 32 33 33 32 33 33 32 33 32 33 33 32 33 32 33 32 33 32 32 33 32 33 32 32 33 32 32 33 32 32 32 33 32 32 32 32 33 32 32 32 32 32 32 0.33133 0.33100 0.33067 0.33034 0.33001 0.32968 0.32935 0.32902 0.32869 0.32837 0.32804 0.32771 0.32738 0.32705 0.32673 0.32640 0.32607 0.32574 0.32542 0.32509 d. c. 0.32476 0.32444 0.32411 0.32378 0.32346 0.32313 0.32281 0.32248 0.32215 0.32183 L. Cos^ 9.95728 9.95722 9.95716 9.95710 9.95704 9.95698 9.95692 9.95686 9.95680 9.95674 9.95668 9.95663 9.95657 9.95651 9.95645 9.95639 9.95633 9.95627 9.95621 9.95615 9.95609 9.95603 9.95597 9.95591 9.95585 0.32150 0.32118 0.32085 0.32053 0.32020 0.31988 0.31956 0.31923 0.31891 0.31858 0.31826 0.31794 0.31761 0.31729 0.31697 0.31664 0.31632 0.31600 0.31568 0.31535 0.31503 0.31471 0.31439 0.31407 0.31374 0.31342 0.31310 0.31278 0.34246 0.31214 0.31182 9.95579 9.95573 9.95567 9.95561 9.95555 9.95549 9.95543 9.95537 9.95531 9.95525 9.95519 9.95513 9.95507 9.95500 9.95494 9.95488 9.95482 9.95476 9.95470 9.95464 9.95458 9.95452 9.95446 9.95440 9.95434 9.95427 9.95421 9.95415 9.95409 9.95403 9.95397 9.95391 9.95384 9.95378 9.95372 9.95366 _d._ 6 6 6 6 6 6 6 6 6 6 5 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 7 6 6 6 6 6 6 6 6 6 6 6 7 6 6 6 6 6 6 7 6 6 6 L.Tang. L. Sin. 64 ° d. 55 54 53 52 51 50 49 48 47 46 45 44 43 42 41 40 39 38 37 _36 35 34 33 32 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 P. P. 33 3.3 3.9 4.4 5.0 5.5 11.0 16.5 22.0 27.5 32 3.2 3.7 4.3 4.8 5.3 10.7 16.0 21.3 26.7 6 7 8 9 10 20 30 40 50 6 7 8 9 10 20 30 40 50 27 2.7 3.2 3.6 4.1 4.5 9.0 13.5 18.0 22.5 26 2.6 3.0 3.5 3.9 4.3 8.7 13.0 17.3 21.7 6 7 8 9 10 20 30 40 50 7 0.7 0.8 0.9 1.1 1.2 2.3 3.5 4.7 5.8 6 7 8 9 10 20 30 40 50 6 0.6 0.7 0.8 0.9 1.0 2.0 3.0 4.0 5.0 5 0.5 0.6 0.7 0.8 0.8 1.7 2.5 3.3 4.2 P. P. 518 LOGARITHMS OF TRIGONOMETRIC FUNCTIONS . ' 26 ° / L. Sin. 0 9.64 L84 1 9.64210 2 9.64236 3 9.64262 4 9.64288 5 9.64313 6 9.64339 7 9.64365 8 9.64391 9 9.64417 10 9.64442 11 9.64468 12 9.64494 13 9.64519 14 9.64545 15 9.64571 16 9.64596 17 9.64622 18 9.64647 19 9.64673 20 9 64698 21 9.34724 22 9.64749 23 9.64775 24 9.64800 25 9.64826 26 9.64851 27 9.64877 28 9.64902 29 9.64927 30 9.64953 31 9.64978 32 9.65003 33 9.65029 34 9.65054 35 9.65079 36 9.65104 37 9.65130 38 9.65155 39 9.65180 40 9.65205 41 9.65230 42 9.65255 43 9.65281 44 9.65306 45 9.65331 46 9.65356 47 9.65381 48 9.65406 49 9.65431 50 9.65456 51 9.65481 52 9.65506 53 9.65531 54 9.65556 55 9.65580 56 9.65605 57 9.65630 58 9.65655 59 9.65680 60 9.65705 L.Tang. ¥.'68818 9.68850 9.68882 9.68914 9.68946 9.68978 9.69010 9.69042 9.69074 9.69106 9.69138 9.69170 9.69202 9.69234 9.69266 9.69298 9.69329 9.69361 9.69393 9.69425 9.69457 9.69488 9.69520 9.69552 9.69584 9.69615 9.69647 9.69679 9.69710 9.69742 9.69774 9.69805 9.69837 9.69868 9.69900 9.69932 . 9.69963 9.69995 9.70026 9.70058 9.70089 9.70121 9.70152 9.70184 9.70215 9.70247 9.70278 9.70309 9.70341 9.70372 9.70404 9.70435 9.70466 9.70498 9.70529 9.70560 9.70592 9.70623 9.70654 9.70685 9.70717 L. Cotg. L. Cotg. L. Cos. 0.31182 9.95366 0.31150 9.95360 0.31118 9.95354 0.31086 9.95348 0.31054 9.95341 0.31022 9.95335 0.30990 9.95329 0.30958 9.95323 0.30926 9.95317 0.30894 9.95310 0.30862 9.95304 0.30830 9.95298 0.30798 9.95292 0.30766 9.95286 0.30734 9.95279 0.30702 9.95273 0.30671 9.95267 0.30639 9.95261 0.30607 9.95254 0.30575 9.95248 0.30543 9.95242 0.30512 9.95236 0.30480 9.95229 0.30448 9.95223 0.30416 9.95217 0.30385 9.95211 0.30353 9.95204 0.30321 9.95198 0.30290 9.95192 0.30258 9.95185 0.30226 9.95179 0.30195 9.95173 0.30163 9.95167 0.30132 9.95160 0.30100 9.95154 0.30068 9.95148 0.30037 9.95141 0.30005 9.95135 0.29974 9.95129 0.29942 9.95122 0.29911 9.95116 0.29879 9.95110 0.29848 9.95103 0.29816 9.95097 0.29785 9.95090 0.29753 9.95084 0.29722 9.95078 0.29691 9.95071 0.29659 9.95065 0.29628 9.95059 0.29596 9.95052 0.29565 9.95046 0.29534 9.95039 0.29502 9.95033 0.29471 9.95027 0.29440 9.95020 ■ 0.29408 9.95014 0.29?77 9.95007 0.29346 9.95001 0.29315 9.94995 0.29283 9.94988 L.Tang. L. Sin. L. Cos. d. 26 26 26 26 25 26 26 26 26 25 26 26 25 26 26 25 26 25 26 25 26 25 26 25 26 25 26 25 25 26 25 25 26 25 25 25 26 25 25 25 25 25 26 25 25 25 25 25 25 25 25 25 25 25 24 25 25 25 25 25 d. c. 32 32 32 32 32 32 32 32 32 32 32 32 32 32 32 31 32 32 32 32 31 32 32 32 31 32 32 31 32 32 31 32 31 32 32 31 32 31 32 31 32 31 32 31 32 31 31 32 31 32 31 31 32 31 31 32 31 31 31 32 d. 60 59 58 57 56 55 54 53 52 5i 50 49 48 47 46 45 44 43 42 41 40 39 38 37 36 35 34 33 32 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 P. P. 32 3.2 3.7 4.3 4.8 5.3 10.7 16.0 21.3 26.7 31 3.1 3.6 4.1 4.7 5.2 10.3 15.5 20.7 25.8 6 n 3 9 10 20 30 40 50 6 7 8 9 10 20 30 40 50 6 7 8 9 10 20 30 40 50 26 2.6 3.0 3.5 3.9 4.3 8.7 13.0 17.3 21.7 25 2.5 2.9 3.3 3.8 4.2 8.3 12.5 16.7 20.8 24 2.4 2.8 3.2 3.6 4.0 8.0 12.0 16.0 20.0 6 7 8 9 10 20 30 40 50 7 0.7 0.8 0.9 1.1 1.2 2.3 3.5 4.7 5.8 0.6 0.7 0.8 0.9 1.0 2.0 3.0 4.0 5.0 P. P. 63 ° LOGARITHMS OF TRIGONOMETRIC FUNCTIONS. 27 ° 519 / L. Sin. 0 9.65705" 1 9.65729 2 9.65754 3 9.65779 4 9.65804 5 9.65828 6 9.65853 7 9.65878 8 9.65902 9 9.65927 10 9.65952 11 9.65976 12 9.66001 13 9.66025 14 9.66050 15 9.66075 16 9.66099 17 9.66124 18 9.66148 19 9.66173 20 9.66197 21 9.66221 22 9.66246 23 9.66270 24 9.66295 25 9.66319 26 9.66343 27 9.66368 28 9.66392 29 9.66416 30 9.66441 31 9.66465 32 9.66489 33 9.66513 34 9.66537 35 9.66562 36 9.66586 37 9.66610 38 9.66634 39 9.66658 40 9.66682 41 9.66706 42 9.66731 43 9.66755 44 9.66779 45 9.66803 46 9.66827 47 9.66851 48 9.66875 49 9.66899 50 9.66922 51 9.66946 52 9.66970 53 9.66994 54 9.67018 55 9.67042 56 9.67066 57 9.67090 58 9.67113 59 9.67137 60 9.67161 L. Cos. L.Tang. 9.70717 9.70748 9.70779 9.70810 9.70841 9.70873 9.70904 9.70935 9.70966 9.70997 9.71028 9.71059 9.71090 9.71121 9.71153 9.71184 9.71215 9.71246 9.71277 9.71308 9.71339 9.71370 9.71401 9.71431 9.71462 9.71493 9.71524 9.71555 9.71586 9.71617 9.71648 9.71679 9.71709 9.71740 9.71771 9.71802 9.71833 9.71863 9.71894 9.71925 9.71955 9.71986 9.72017 9.72048 9.72078 9.72109 9.72140 9.72170 9.72201 9.72231 9.72262 9.72293 9.72323 9.72354 9.72384 9.72415 9.72445 9.72476 9.72506 9.72537 9.72567 L. Cotg. d. 24 25 25 25 24 25 25 24 25 25 24 25 24 25 25 24 25 24 25 24 24 25 24 25 24 24 25 24 24 25 24 24 24 24 25 24 24 24 24 24 24 25 24 24 24 24 24 24 24 23 24 24 24 24 24 24 24 23 24 24 d. d. c. 31 31 31 31 32 31 31 31 31 31 31 31 31 32 31 31 31 31 31 31 31 31 30 31 31 31 31 31 31 31 31 30 31 31 31 31 30 31 31 30 31 31 31 30 31 31 30 31 30 31 31 30 31 30 31 30 31 30 31 30 |L. Cot g. 0.29283 0.29252 0.29221 0.29190 0.29159 0.29127 0.29096 0.29065 0.29034 0.29003 0.28972 0.28941 0.28910 0.28879 0.28847 0.28816 0.28785 0.28754 0.28723 0.28692 0.28661 0.28630 0.28599 0.28569 0.28538 0.28507 0.28476 0.28445 0.28414 0.28383 0.28352 0.28321 0.28291 0.28260 0.28229 0.28198 0.28167 0.28137 0.28106 0.28075 0.28045 0.28014 0.27983 0.27952 0.27922 0.27891 0.27860 0.27830 0.27799 0.27769 0.27738 0.27707 0.27677 0.27646 0.27616 0.27585 0.27555 0.27524 0.27494 0.27463 0.27433 d. c. L.Tang L. Cos. d. 9.94988" 9.94982 9.94975 9.94969 9.94962 9.94956 9.94949 9.94943 9.91936 9.94930 9.94923 9.94917 9.94911 9.94904 9.94898 9.94891 9.94885 9.94878 9.94871 9.94865 9.94858 9.94852 9.94845 9.94839 9.94832 9.94826 9.94819 9.94813 9.94806 9.94799 9.94793 9.94786 9.94780 9.94773 9.94767 9.94760 9.94753 9.94747 9.94740 9.94734 9.94727 9.94720 9.94714 9.94707 9.94700 9.94694 9.94687 9.94680 9.94674 9.94667 9.94660 9.94654 9.94647 9.94640 9.94634 9.94627 9.94620 9.94614 9.94607 9.94600 9.94593 L. Sin. d P. P. 32 3.2 3.7 4.3 4.8 5.3 10.7 16.0 21.3 26.7 31 3.1 3.6 4.1 4.7 5.2 10.3 15.5 20.7 25.8 6 7 •8 9 10 20 30 40 50 30 3.0 3.5 4.0 4.5 5.0 10.0 15.0 20.0 25.0 25 2.5 2.9 3.3 3.8 4.2 8.3 12.5 16.7 20.8 24 2.4 2.8 3.2 3.6 4.0 8.0 12.0 16.0 20.0 6 7 8 9 10 20 30 40 50 23 2.3 2.7 3.1 3.5 3.8 7.7 11.5 15.3 19.2 6 7 8 9 10 20 30 40 50 7 0.7 0.8 0.9 1.1 1.2 2.3 3.5 4.7 5.8 6 0.6 0.7 0.8 0.9 1.0 2.0 3.0 4.0 5.0 P. P. 62 ° 520 LOGARITHMS OF TRIGONOMETRIC FUNCTIONS. 28 ° ' 1 L. Sin. 0 9.67161 1 9.67185 2 9.67208 3 9.67232 4 9.67256 5 9.67280 6 9.67303 7 9.67327 8 9.67350 9 9.67374 10 9.67398 11 9.67421 12 9.67445 13 9.67468 14 9.67492 15 9.67515 16 9.67539 17 9.67562 18 9.67586 19 9.67609 20 9„67633 21 9.67656 22 9.67680 23 9.67703 24 9.67726 25 9.67750 26 9.67773 27 9.67796 28 9.67820 29 9.67843 30 9.67866 31 9.67890 32 9.67913 33 9.67936 34 9.67959 35 9.67982 36 9.68006 37 9.68029 38 9.68052 39 9.68075 40 9.68098 41 9.68121 42 9.68144 43 9.68167 44 9.68190 45 9.68213 46 9.68237 47 9.68260 48 9.68283 49 9.68305 50 9.68328 51 9.68351 52 9.68374 53 9.68397 54 9.68420 55 9.68443 56 9.68466 57 9.68489 58 9.68512 59 9.68534 60 9.68557 L. Cos. P. P. 31 30 1 6 3.1 3.0 7 3.6 3.5 8 4.1 4.0 9 4.7 4.5 10 5.2 5.0 20 10.3 10.0 30 15.5 15.0 40 20.7 20.0 50 25.8 25.0 29 6 2.9 7 3.4 8 3.9 9 4.4 10 4.8 20 9.7 1 30 14.5 40 19.3 50 24.2 24 23 6 2.4 2.3 7 2.8 2.7 8 3.2 3.1 - . 9 3.6 3.5 10 4.0 3.8 20 8.0 7.7 30 12.0 11.5 > 40 16.0 15.3 - 50 20.0 19.2 22 6 2.2 7 2.6 8 2.9 9 3.3 10 3.7 20 7.3 30 11.0 40 14.7 50 18.3 7 6 i 6 0.7 0.6 i 7 0.8 0.7 i 8 0.9 0.8 9 1.1 0.9 * 10 1.2 1.0 , 20 2.3 2.0 t 30 3.5 3.0 ; 40 4.7 4.0 » 50 5.8 5.0 1 d. L.Tang. 24 23 24 24 24 23 24 23 24 24 23 24 23 24 23 24 23 24 23 24 23 24 23 23 24 23 23 24 23 23 24 23 23 23 23 24 23 23 23 23 23 23 23 23 23 24 23 23 22 23 23 23 23 23 23 23 23 23 22 23 d. 9.72567 9.72598 9.72628 9.72659 9.72689 9.72720 9o72750 9.72780 9.72811 9.72841 9.72872 9.72902 9.72932 9.72963 9.72993 9.73023 9.73054 9.73084 9.73114 9.73144 9.73175 9.73205 9.73235 9.73265 9.73295 d. c. 9.73326 9.73356 9.73386 9.73416 9.73446 9.73476 9.73507 9.73537 9.73567 9.73597 9.73627 9.73657 9.73687 9.73717 9.73747 9.73777 9.73807 9.73837 9.73867 9.73897 9.73927 9.73957 9.73987 9.74017 9.74047 9.74077 9.74107 9.74137 9.74166 9.74196 9.74226 9.74256 9.74286 9.74316 9.74345 31 30 31 30 31 30 30 31 30 31 30 30 31 30 30 31 30 30 30 31 30 30 30 30 31 30 30 30 30 30 31 30 30 30 30 30 30 30 30 30 30 30 30 30 30 30 30 30 9.74375 L. Cotg. L. Cotg. 30 30 30 30 29 30 30 30 30 30 29 30 0.27433 0.27402 0.27372 0.27341 0.27311 9.94593 9.94587 9.94580 9.94573 9.94567 0.27280 0.27250 0.27220 0.27189 0.27159 0.27128 0.27098 0.27068 0.27037 0.27007 0.26977 0.26946 0.26916 0.26886 0.26856 0.26825 0.26795 0.26765 0.26735 0.26705 0.26674 0.26644 0.26614 0.26584 0.26554 0.26524 0.26493 0.26463 0.26433 0.26403 0.26373 0.26343 0.26313 0.26283 0.26253 0.26223 0.26193 0.26163 0.26133 0.26103 0.26073 0.26043 0.26013 0.25983 0.25953 0.25923 0.25893 0.25863 0.25834 0.25804 0.25774 0.25744 0.25714 0.25684 0.25655 0.25625 d. c. L.Tang 61 ° L. Cos. d. 9.94560 9.94553 9.94546 9.94540 9.94533 9.94526 9.94519 9.94513 9.94506 9.94499 9.94492 9.94485 9.94479 9.94472 9.94465 9.94458 9.94451 9.94445 9.94438 9.94431 9.94424 9.94417 9.94410 9.94404 9.94397 9.94390 9.94383 9.94376 9.94369 9.94362 9.94355 9.94349 9.94342 9.94335 9.94328 9.94321 9.94314 9.94307 9.94300 9.94293 9.94286 9.94279 9.94273 9.94266 9.94259 9.94252 9.94245 9.94238 9.94231 9.94224 9.94217 9.94210 9.94203 9.94196 9.94189 9.94182 L. Sin. d 6 7 7 6 7 7 7 6 7 7 7 6 7 7 7 7 6 7 7 7 7 6 7 7 7 7 7 6 7 7 7 7 7 7 7 6 7 7 7 7 7 7 7 7 7 7 6 7 7 7 7 7 7 7 7 7 7 7 7 7 10 P. P. 52.1 LOGARITHMS OF TRIGONOMETRIC FUNCTIONS . 29 ° / L. Sin. d. L.Tang. d. c. L. Cotg. L. Cos. d. P. P. 0 9.68557 9.74375 0.25625 9.94182 60 1 9.68580 23 9.74405 30 0.25595 9.94175 7 59 2 9.68603 23 9.74435 30 0.25565 9.94168 7 58 3 9.68625 22 9.74465 30 0.25535 9.94161 7 57 a ou O A 4 9.68648 23 Oq 9.74494 29 QO 0.25506 9.94154 7 7 56 D 7 3.0 3.5 5 9.68671 9.74524 0.25476 9.94147 by 55 8 4.0 6 9.68694 23 9.74554 30 0.25446 9.94140 7 54 9 4.5 7 9.68716 22 9.74583 29 0.25417 9.94133 7 53 10 5.0 8 9.68739 23 9.74613 30 0.25387 9.94126 7 52 20 10.0 9 9.68762 23 22 9.74643 30 30 0.25357 9.94119 7 7 51 30 15.0 10 9.68784 9.74673 0.25327 9.94112 50 40 20.0 11 9.68807 23 9.74702 29 0.25298 9.94105 7 49 50 25.0 12 9.68829 22 9.74732 30 0.25268 9.94098 7 48 13 9.68852 23 9.74762 30 0.25238 9.94090 8 47 14 9.68875 23 99 9.74791 29 30 0.25209 9.94083 7 7 46 29 15 9.68897 9.74821 0.25179 9.94076 « by 45 6 2.9 16 9.68920 23 9.74851 30 0.25149 9.94069 7 44 1 3.4 17 9.68942 22 9.74880 29 0.25120 9.94062 7 43 8 3.9 18 9.68965 23 9.74910 30 0.25090 9.94055 7 42 9 4.4 19 9.68987 22 ) 23 9.74939 29 30 0.25061 9.94048 7 7 41 10 4.8 20 9.69010 9.749&9 0.25031 9.94041 40 20 9.7 21 9.69032 22 9.74998 29 0.25002 9.94034 7 39 30 14.5 22 9.69055 23 9.75028 30 0.24972 9.94027 7 38 40 19.3 23 9.69077 22 9.75058 30 0.24942 9.94020 7 37 50 24.2 24 9.69100 23 99 9.75087 29 30 0.24913 9.94012 8 7 36 25 9.69122 9.75117 0.24883 9.94005 fy 35 26 9.69144 22 9.75146 29 0.24854 9.93998 7 34 23 27 9.69167 23 9.75176 30 0.24824 9.93991 7 33 6 2.3 28 9.69189 22 9.75205 29 0.24795 9.93984 7 32 7 2.7 29 9.69212 23 9.75235 30 0.24765 9.93977 7 31 8 3.1 22 29 *1 30 9.69234 9.75264 0.24736 9.93970 4 by 30 1 A 6.0 o o 31 9.69256 22 9.75294 30 0.24706 9.93963 7 29 10 3.8 <7 >1 32 9.69279 23 9.75323 29 0.24677 9.93955 8 28 20 OA 7.7 33 9.69301 22 9.75353 30 0.24647 9.93948 7 27 30 A(\ 11.0 1C Q 34 9.69323 22 22 9.75382 29 9Q 0.24618 9.93941 7 7 26 R0 10.3 IQ 9 35 9.69345 9.75411 0.24589 9.93934 f by 25 36 9.69368 23 9.75441 30 0.24559 9.93927 7 24 37 9.69390 22 9.75470 29 0.24530 9.93920 7 23 38 9.69412 22 9.75500 30 0.24500 9.93912 8 22 ZZ 39 9.69434 22 22 9.75529 29 29 0.24471 9.93905 7 7 21 6 7 2.2 9 A 40 9.69456 9.75558 0.24442 9.93898 f ty 20 « Z.O 2.9 41 9.69479 23 9.75588 30 0.24412 9.93891 7 19 l 3 3*3 42 9.69501 22 9.75617 29 0.24383 9.93884 7 18 10 8.7 43 9.69523 22 9.75647 30 0.24353 9.93876 8 17 20 7.3 44 9.69545 22 22 9.75676 29 29 0.24324 9.93869 7 7 16 30 11.0 45 9.69567 9.75705 0.24295 9.93862 i by 15 40 14.7 46 9.69589 22 9.75735 30 0.24265 9.93855 7 14 50 18.3 47 9.69611 22 9.75764 29 0.24236 9.93847 8 13 48 9.69633 22 9.75793 29 0.24207 9 93840 7 12 49 9.69655 22 22 9.75822 29 qn 0.24178 9.93833 7 7 11 ft a 50 9.69677 9.75852 ou 0.24148 9.93826 i 10 6 0.8 0)7 51 9.69699 22 9.75881 29 0.24119 9.93819 7 9 7 0.9 0.8 52 9.69721 22 9.75910 29 0.24090 9.93811 8 8 8 1.1 0.9 53 9.69743 22 9.75939 29 0.24061 9.93804 7 7 9 1.2 1.1 54 9.69765 22 22 9.75969 30 29 0.24031 9.93797 7 8 6 10 1.3 1.2 55 9.69787 9.75998 0.24002 9.93789 5 20 2.7 2.3 56 9.69809 22 9.76027 29 0.23973 9.93782 7 4 30 4.0 3.5 57 9.69831 22 9.76056 29 0.23944 9.93775 7 3 40 5.3 4.7 58 9.69853 22 9.76086 30 0.23914 9.93768 7 2 50 6.7 5.8 59 9.69875 22 22 9.76115 29 29 0.23885 9.93760 8 7 1 60 9.69897 9.76144 0.23856 9.93753 4 0 L. Cos. d. L. Cotg. d. c. L.Tang. L. Sin. d. / P. P. 60 ° 522 LOGARITHMS OF TRIGONOMETRIC FUNCTIONS. 30 ° r L. Sin. d. L.Tang. d. c. L. Cotg. L. Cos. d. P. P. 0 1 2 3 4 9.69897 9.69919 9.69941 9.69963 9.69984 22 22 22 21 22 22 22 22 21 22 22 22 21 22 22 21 22 21 22 22 21 22 21 22 21 22 21 22 21 22 A 22 21 22 21 21 22 21 21 22 21 21 21 22 21 21 21 22 21 - 21 21 21 21 22 - 21 21 21 21 21 91 9.76144 9.76173 9.76202 9.76231 9.76261 29 29 29 30 29 29 29 29 29 29 29 29 29 29 29 29 30 29 29 28 29 29 29 29 29 29 29 29 29 29 29 29 28 29 29 29 29 29 28 29 29 29 29 28 29 29 29 ( 28 29 29 28 29 29 29 - 28 29 28 29 29 Oft 0.23856 0.23827 0.23798 0.23769 0.23739 9.93753 9.93746 9.93738 9.93731 9.93724 7 8 7 7 7 8 7 7 8 7 7 8 7 8 7 7 8 7 7. 8 7 8 7 7 8 7 8 7 8 7 7 8 7 8 7 8 7 8 7 8 7 8 7 8 7 8 7 8 7 - 8 7 8 7 8 - 8 7 8 7 8 - 7 60 59 58 57 56 30 29 6 3.0 2.9 7 3.5 3.4 8 4.0 3.9 9 4.5 4.4 10 5.0 4.8 20 10.0 9.7 30 15.0 14.5 40 20.0 19.3 50 25.0 24.2 28 6 2.8 7 3.3 8 3.7 9 4.2 10 4.7 20 9.3 30 14.0 40 18.7 50 23.3 22 6 2.2 7 2.6 8 2.9 9 3.3 10 3.7 20 7.3 30 11.0 40 14.7 50 18.3 2^ 6 2.1 7 2.5 8 2.8 9 3.2 10 3.5 20 7.0 30 10.5 40 14.0 50 17.5 8 7 6 0.8 0.7 7 0.9 0.8 8 1.1 0.9 9 1.2 1.1 10 1.3 1.2 20 2.7 2.3 30 4.0 3.5 40 5.3 4.7 50 6.7 5.8 5 6 7 8 9 9.70006 9.70028 9.70050 9.70072 9.70093 9.76290 9.76319 9.76348 9.76377 9.76406 0.23710 0.23681 0.23652 0.23623 0.23594 9.93717 9.93709 9.93702 9.93695 9.93687 55 54 53 52 51 10 11 12 13 14 9.70115 9.70137 9.70159 9.70180 9.70202 9.76435 9.76464 9.76493 9.76522 9.76551 0.23565 0.23536 0.23507 0.23478 0.23449 9.93680 9.93673 9.93665 9.93658 9.93650 50 49 48 47 46 15 16 17 18 19 9.70224 9.70245 9.70267 9.70288 9.70310 9.76580 9.76609 9.76639 9.76668 9.76697 0.23420 0.23391 0.23361 0.23332 0.23303 9.93643 9.93636 9.93628 9.93621 9.93614 45 44 43 42 41 20 21 22 23 24 9.70332 9.70353 9.70375 9.70396 9.70418 9.76725 9.76754 9.76783 9.76812 9.76841 0.23275 0.23246 0.23217 0.23188 0.23159 9.93606 9.93599 9.93591 9.93584 9.93577 40 39 38 37 36 25 26 27 28 29 9.70439 9.70461 9.70482 9.70504 9.70525 9.76870 9.76899 9.76928 9.76957 9.76986 0.23130 0.23101 0.23072 0.23043 0.23014 9.93569 9.93562 9.93554 9.93547 9.93539 35 34 33 32 31 30 31 32 33 34 9.70547 9.70568 9.70590 9.70611 9.70633 9.77015 9.77044 9.77073 9.77101 9.77130 0.22985 0.22956 0.22927 0.22899 0.22870 9.93532 9.93525 9.93517 9.93510 9.93502 30 29 28 27 26 35 36 37 38 39 9.70654 9.70675 9.70697 9.70718 9.70739 9.77159 9.77188 9.77217 9.77246 9.77274 0.22841 0.22812 0.22783 0.22754 0.22726 9.93495 9.93487 9.93480 9.93472 9.93465 25 24 23 22 21 40 41 42 43 44 9.70761 9.70782 9.70803 9.70824 9.70846 9.77303 9.77332 9.77361 9.77390 9.77418 0.22697 0.22668 0.22639 0.22610 0.22582 9.93457 9.93450 9.93442 9.93435 9.93427 20 19 18 17 16 45 46 47 48 49 9.70867 9.70888 9.70909 9.70931 9.70952 • 9.77447 9.77476 9.77505 9.77533 9.77562 0.22553 0.22524 0.22495 0.22467 0.22438 9.93420 9.93412 9.93405 9.93397 9.93390 15 14 13 12 11 50 51 52 53 54 ’ 9.70973 9.70994 9.71015 9.71036 9.71058 9.77591 9.77619 9.77648 9.77677 9.77706 0.22409 0.22381 0.22352 0.22323 0.22294 9.93382 9.93375 9.93367 9.93360 9.93352 lo 9 8 7 6 55 56 57 58 59 9.71079 9.71100 9.71121 9.71142 9.71163 9.77734 9.77763 9.77791 9.77820 9.77849 0.22266 0.22237 0.22209 0.22180 0.22151 9.93344 9.93337 9.93329 9.93322 9.93314 5 4 3 2 1 60 " 9771184 9.77877 AdCj 0.22123 9.93307 0 L. Cos. d. L. Cotg . d. c. L.Tang . L. Sin. d. / P. P. 59 ° LOGARITHMS OF TRIGONOMETRIC FUNCTIONS. 523 31 ° f L. Sin. d. L.Tang. d. c. L. Cotg. L. Cos. d. P. P. 0 1 2 3 4 5 6 7 8 9 9.71184 9.71205 9.71226 9.71247 9.71268 21 21 21 21 21 21 21 21 21 20 21 21 21 21 21 21 20 21 21 21 20 21 21 21 20 21 21 20 21 21 20 21 20 21 20 21 20 21 21 20 20 21 20 21 20 21 20 20 21 ,20 20 21 20 20 21 20 20 21 20 20 9.77877 9.77906 9.77935 9.77963 .9.77992 29 29 28 29 28 29 28 29 29 28 29 28 29 28 29 28 29 28 28 29 28 29 28 29 28 28 29 28 29 28 28 29 28 28 29 28 28 29 28 28 28 29 28 28 28 29 28 28 28 28 29 28 28 28 28 28 29 28 28 - 28 0.22123 0.22094 0.22065 0.22037 0.22008 9.93307 9.93299 9.93291 9.93284 9.93276 8 8 7 8 7 8 8 7 8 8 7 8 8 7 8 8 7 8 8 7 8 8 7 8 8 7 8 8 8 7 8 8 8 7 8 8 8 8 7 8 8 8 7 8 8 8 8 8 7 8 8 8 8 8 8 7 8 8 8 8 60 59 58 57 56 55 54 53 52 51 29 6 2.9 7 3.4 8 3.9 9 4.4 10 4.8 20 9.7 30 14.5 40 19.3. 50 24.2 28 6 1 2.8 7 3.3 8 3.7 9 4.2 10 4.7 20 9.3 30 14.0 40 18.7 50 23.3 21 6 2.1 7 2.5 8 2.8 9 3.2 10 3.5 20 7.0 30 10.5 40 14.0 50 17.5 20 6 2.0 7 2.3 8 2.7 9 3.0 10 3.3 20 6.7 30 10.0 40 13.3 50 16.7 8 7 6 0.8 0.7 7 0.9 0.8 8 1.1 0.9 9 1.2 1.1 10 1.3 1.2 20 2.7 2.3 30 4.0 3.5 40 5.3 4.7 50 6.7 5.8 9.71289 9.71310 9.71331 9.71352 .9.71373 9.78020 9.78049 9.78077 9.78106 9.78135 0.21980 0.21951 0.21923 0.21894 0.21865 9.93269 9.93261 9.93253 9.93246 9.93238 10 11 12 13 14 9.71393 9.71414 9.71435 9.71456 9.71477 9.78163 9.78192 9.78220 9.78249 9.78277 0.21837 0.21808 0.21780 0.21751 0.21723 9.93230 9.93223 9.93215 9.93207 9.93200 50 49 48 47 46 15 16 17 18 19 9.71498 9.71519 9.71539 9.71560 9.71581 9.78306 9.78334 9.78363 9.78391 9.78419 0.21694 0.21666 0.21637 0.21609 0.21581 9.93192 9.93184 9.93177 9.93169 9.93161 45 44 43 42 41 20 21 22 23 24 9.71602 9.71622 9.71643 9.71664 9.71685 9.78448 9.78476 9.78505 9.78533 9.78562 0.21552 0.21524 0.21495 0.21467 0.21438 9.93154 9.93146 9.93138 9.93131 9.93123 40 39 38 37 36 25 26 27 28 29 9.71705 9.71726 9.71747 9.71767 9.71788 9.78590 9.78618 9.78647 9.78675 9.78704 0.21410 0.21382 0.21353 0.21325 0.21296 9.93115 9.93108 9.93100 9.93092 9.93084 35 34 33 32 31 30 31 32 33 34 9.71809 9.71829 9.71850 9.71870 9.71891 9.78732 9.78760 9.78789 9.78817 9.78845 0.21268 0.21240 0.21211 0.21183 0.21155 9.93077 9.93069 9.93061 9.93053 9.93046 30 29 28 27 26 35 36 37 38 39 9.71911 9.71932 9.71952 9.71973 9.71994 9.78874 9.78902 9.78930 9.78959 9.78987 0.21126 0.21098 0.21070 0.21041 0.21013 9.93038 9.93030 9.93022 9.93014 9.93007 25 24 ^23 22 21 40 41 42 43 44 9.72014 9.72034 9.72055 9.72075 9.72096 9.79015 9.79043 9.79072 9.79100 9.79128 0.20985 0.20957 0.20928 0.20900 0.20872 9.92999 9.92991 9.92983 9.92976 9.92968 20 19 18 17 16 45 46 47 48 49 9.72116 9.72137 9.72157 9.72177 9.72198 9.79156 9.79185 9.79213 9.79241 9.79269 0.20844 0.20815 0.20787 0.20759 0.20731 9.92960 9.92952 9.92944 9.92936 9.92929 15 14 13 12 11 50 51 52 53 54 9.72218' 9.72238 9.72259 9.72279 9.72299 9.79297 9.79326 9.79354 9.79382 9.79410 0.20703 0.20674 0.20646 0.20618 0.20590 9.92921 9.92913 9.92905 9.92897 9.92889 10 9 8 7 6 55 56 57 58 59 9.72320 9.72340 9.72360 9.72381 9.72401 9.79438 9.79466 9.79495 9.79523 9.79551 0.20562 0.20534 0.20505 0.20477 0.20449 9.92881 9.92874 9.92866 9.92858 9.92850 5 4 3 2 1 60 9.72421 L. Cos. 9.79579 0.20421 9.92842 0 d. L. Cotg . d. c. L.Tang. . L. Sin. d. / P. P. 58 ° 524 LOGARITHMS OF TRIGONOMETRIC FUNCTIONS. 32 ° / L. Sin. 0 9.72421 1 9.72441 2 9.72461 3 9.72482 4 9.72502 5 9.72522 6 9.72542 7 9.72562 8 9.72582 9 9.72602 10 9.72622 11 9.72643 12 9.72663 13 9.72683 14 9.72703 15 9.72723 16 9.72743 17 9.72763 18 9.72783 19 9.72803 20 9.72823 21 9.72843 22 9.72863 23 9.72883 24 9.72902 25 9.72922 26 9.72942 27 9.72962 28 9.72982 29 9.73002 30 9.73022 31 9.73041 32 9.73061 33 9.73081 34 9.73101 35 9.73121 36 9.73140 37 9.73160 38 9.73180 39 9.73200 40 9.73219 41 9.73239 42 9.73259 43 9.73278 44 9.73298 45 9.73318 46 9.73337 47 9.73357 48 9.73377 49 9.73396 50 9.73416 51 9.73435 52 9.73455 53 9.73474 54 9.73494 55 9.73513 56 9.73533 57 9.73552 58 9.73572 59 9.73591 60 9.73611 L.Cos. d. L.Tang. 20 20 21 20 20 20 20 20 20 20 21 20 20 20 20 20 20 20 20 20 20 20 20 19 20 20 20 20 20 20 19 20 20 20 20 19 20 20 20 19 20 20 19 20 20 19 20 20 19 20 19 20 19 20 19 20 19 20 19 20 9.79579 9.79607 9.79635 9.79663 9.79691 9.79719 9.79747 9.79776 9.79804 9.79832 9.79860 9.79888 9.79916 9.79944 9.79972 9.80000 9.80028 9.80056 9.80084 9.80112 9.80140 9.80168 9.80195 9.80223 9.80251 9.80279 9.80307 9.80335 9.80363 9.80391 9.80419 9.80447 9.80474 9.80502 9.80530 9.80558 9.80586 9.80614 9.80642 9.80669 9.80697 9.80725 9.80753 9.80781 9.80808 9.80836 9.80864 9.80892 9.80919 9.80947 9.80975 9.81003 9.81030 9.81058 9.810 86 9.81113 9.81141 9.81169 9.81196 9.81224 9.81252 d. c. 28 28 28 28 28 28 29 28 28 28 28 28 28 28 28 28 28 28 28 28 28 27 28 28 28 28 28 28 28 28 28 27 28 28 28 28 28 28 27 28 28 28 28 27 28 28 28 27 28 28 28 27 28 28 27 28 28 27 28 28 d. L. Cotg. d. c L. Cotg. L. Cos. 0.20421 9.92842 0.20393 9.92834 0.20365 9.92826 0.20337 9.92818 0.20309 9.92810 0.20281 9.92803 0.20253 9.92795 0.20224 9.92787 0.20196 9.92779 0.20168 9.92771 0.20140 9.92763 0.20112 9.92755 0.20084 9.92747 0.20056 9.92739 0.20028 9.92731 0.20000 9.92723 0.19972 9.92715 0.19944 9.92707 0.19916 9.92699 0.19888 9.92691 0.19860 9.92683 0.19832 9.92675 0.19805 9.92667 0.19777 9.92659 0.19749 9.92651 0.19721 9.92643 0.19693 9.92635 0.19665 9.92627 0.19637 9.92619 0.19609 9.92611 0.19581 9.92603 0.19553 9.92595 0.19526 9.92587 0.19498 9.92579 0.19470 9.92571 0.19442 9.92563 0.19414 9.92555 0.19386 9.92546 0.19358 9.92538 0.19331 9.92530 0.19303 9.92522 0.19275 9.92514 0.19247 9.92506 0.19219 9.92498 0.19192 9.92490 0.19164 9.92482 0.19136 9.92473 0.19108 9.92465 0.19081 9.92457 0.19053 9.92449 0.19025 9.92441 0.18997 9.92433 0.18970 9.92425 0.18942 9.92416 0.18914 9.92408 0.18887 9.92400 0.18859 9.92392 0.18831 9.92384 0.18804 9.92376 0.18776 9.92367 0.18748 9.92359 L.Tang, . L. Sin. 8 8 8 8 7 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 9 8 8 8 8 8 8 8 8 9 8 8 8 8 8 8 9 8 8 8 8 8 9 8 P. P. 29 28 6 2.9 2.8 7 3.4 3.3 8 3.9 3.7 9 4.4 4.2 10 4.8 4.7 20 9.7 9.3 30 14.5 14.0 40 19.3 18.7 50 24.2 23.3 27 6 2.7 7 3.2 8 3.6 9 4.1 10 4.5 20 9.0 30 13.5 40 18.0 50 22.5 21 20 6 ! 2.1 2.0 7 2.5 2.3 8 2.8 2.7 - 9 3.2 3.0 10 3.5 3.3 20 7.0 6.7 30 10.5 10.0 40 14.0 13.3 - 50 17.5 16.7 19 6 1.9 7 2.2 8 2.5 9 2.9 10 3.2 20 6.3 30 9.5 40 12.7 50 15.8 9 8 7 6 0.9 0.8 0.7 7 1.1 0.9 0.8 8 1.2 1.1 0.9 9 1.4 1.2 1.1 10 1.5 1.3 1.2 20 3.0 2.7 2.3 30 4.5 4.0 3.5 40 6.0 5.3 4.7 50 7.5 6.7 5.8 P. , I > 57 ° LOGARITHMS OF TRIGONOMETRIC FUNCTIONS. 525 f L. Sin. 0 9.73611 1 9,73630 2 9.73650 3 9.73669 4 9.73689 5 9.73708 6 9.73727 7 9.73747 8 9.73766 9 9.73785 10 9.73805 11 9.73824 12 9.73843 13 9.73863 14 9.73882 15 9.73901 16 9.73921 17 9.73940 18 9.73959 19 9.73978 20 9.73997 21 9.74017 22 9.74036 23 9.74055 24 9.74074 25 9.74093 26 9.74113 27 9.74132 28 9.74151 29 9.74170 30 9.74189 31 9.74208 32 9.74227 33 9.74246 34 9.74265 35 9.74284 36 9.74303 37 9.74322 38 9.74341 39 9.74360 40 9.74379 41 9.74398 42 9.74417 43 9.74436 44 9.74455 45 9.74474 46 9.74493 47 9.74512 48 9.74531 49 9.74549 50 9.74568 51 9.74587 52 9.74606 53 9.74625 54 9.74644 55 9.74662 56 9.74681 57 9.74700 58 9.74719 59 9.74737 60 9.74756 L. Cos. d. 19 20 19 20 19 19 20 19 19 20 19 19 20 19 19 20 19 19 19 19 20 19 19 19 19 20 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 18 19 19 19 19 19 18 19 19 19 18 19 L.Tang. d. c. : L. Cotg. L. Cos. 9.81252 0.18748 9.92359 9.81279 27 0.18721 9.92351 9.81307 28 0.18693 9.92343 9.81335 28 0.18665 9.92335 9.81362 27 OG 0.18638 9.92326 9.81390 Zo 0.18610 9.92318 9.81418 28 0.18582 9.92310 9.81445 27 0.18555 9.92302 9.81473 28 0.18527 9.92293 9.81500 27 OG 0.18500 9.92285 9.81528 Zo 0.18472 9.92277 9.81556 28 0.18444 9.92269 9.81583 27 0.18417 9.92260 9.81611 28 0.18389 9.92252 9.81638 27 OQ 0.18362 9.92244 9.81666 Zo 0.18334 9.92235 9.81693 27 0.18307 9.92227 9.81721 28 0.18279 9.92219 9.81748 27 0.18252 9.92211 9.81776 28 07 0.18224 9.92202 9.81803 Zl 0.18197 9.92194 9.81831 28 0.18169 9.92186 9.81858 27 0.18142 9.92177 9.81886 28 0.18114 9.92169 9.81913 27 OG 0.18087 9.92161 9.81941 Zo 0.18059 9.92152 9.81968 27 0.18032 9.92144 9.81996 28 0.18004 9.92136 9.82023 27 0.17977 9.92127 9.82051 28 07 0.17949 9.92119 9.82078 Zl 0.17922 9.92111 9.82106 28 0.17894 9.92102 9.82133 27 0.17867 9.92094 9.82161 28 0.17839 9.92086 9.82188 27 07 0.17812 9.92077 9.82215 Zl 0.17785 9.92069 9.82243 28 0.17757 9.92060 9.82270 27 0.17730 9.92052 9.82298 28 0.17702 9.92044 9.82325 27 07 0.17675 9.92035 9.82352 Zl 0.17648 9.92027 9.82380 28 0.17620 9.92018 9.82407 27 0.17593 9.92010 9.82435 28 0.17565 9.92002 9.82462 27 07 0.17538 9.91993 9.82489 Zl 0.17511 9.91985 9.82517 28 0.17483 9.91976 9.82544 27 0.17456 9.91968 9.82571 27 0.17429 9.91959 9.82599 28 27 0.17401 9.91951 9.82626 0.17374 9.91942 9.82653 27 0.17347 9.91934 9.82681 28 0.17319 9.91925 9.82708 27 0.17292 9.91917 9.82735 27 07 0.17265 9.91908 9.82762 Zl 0.17238 9.91900 9.82790 28 0.17210 9.91891 9.82817 27 0.17183 9.91883 9.82844 27 0.17156 9.91874 9.82871 27 - 28 0.17129 9.91866 9.82899 0.17101 9.91857 L. Cotg . d. c. L.Tang . L. Sin. d. 8 8 8 9 8 8 8 9 8 8 8 9 8 8 9 8 8 8 9 8 8 9 8 8 9 8 8 9 8 8 9 8 8 9 8 9 8 8 9 8 9 8 8 9 8 9 8 9 8 9 8 9 8 9 8 9 8 9 8 9 ~ d7 60 59 58 57 56_ 55 54 53 52 51 35 34 33 32 31 36 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 a ii to 9 8 7 6 5 4 3 2 1 0 P. P. 28 2.8 3.3 3.7 4.2 4.7 9.3 14.0 18.7 23.3 27 2.7 3.2 3.6 4.1 4.5 9.0 13.5 18.0 22.5 6 7 8 9 10 20 30 40 50 6 7 8 9 10 20 30 40 50 6 7 8 9 10 20 30 40 50 20 2.0 2.3 2.7 3.0 3.3 6.7 10.0 13.3 16.7 19 1.9 2.2 2.5 2.9 3.2 6.3 9.5 12.7 15.8 18 1.8 2.1 2.4 2.7 3.0 6.0 9.0 12.0 15.0 6 7 8 9 10 20 30 40 50 9 0.9 1.1 1.2 1.4 1.5 3.0 4.5 6.0 7.5 0.8 0.9 1.1 1.2 1.3 2.7 4.0 5.3 6.7 P. P. 5S C 526 LOGARITHMS OF TRIGONOMETRIC FUNCTIONS. 34 ° t L. Sin. 0 9.74756 1 9.74775 2 9.74794 3 9.74812 4 9.74831 5 9.74850 6 9.74868 7 9.74887 8 9.74906 9 9.74924 10 9.74943 11 9.74961 12 9.74980 13 9.74999 14 9.75017 15 9.75036 16 9.75054 17 9.75073 18 9.75091 19 9.75110 20 9.75128 21 9.75147 22 9.75165 23 9.75184 24 9.75202 25 9.75221 26 9.75239 27 9.75258 28 9.75276 29 9.75294 30 9.75313 31 9.75331 32 9.75350 33 9.75368 34 9.75386 35 9.75405 36 9.75423 37 9.75441 38 9.75459 39 9.75478 40 9.75496 41 9.75514 42 9.75533 43 9.75551 44 9.75569 45 9.75587 46 9.75605 47 9.75624 48 9.75642 49 9.75660 50 9.75678 51 9.75696 52 9.75714 53 9.75733 54 9.75751 55 9.75769 56 9.75787 57 9.75805 58 9.75823 59 9.75841 60 9.75859 d. L.Tang. L. Cos. 19 19 18 19 19 18 19 19 18 19 18 19 19 18 19 18 19 18 19 18 19 18 19 18 19 18 19 18 18 19 18' 19 18 18 19 18 18 18 19 18 18 19 18 18 18 18 19 18 • 18 18 18 18 19 18 18 18 18 18 18 18 9.82899 9.82926 9.82953 9.82980 9.83008 9.83035 9.83062 9.83089 9.83117 9.83144 9.83171 9.83198 9.83225 9.83252 9.83280 9.83307 9.83334 9.83361 9.83388 9.83415 9.83442 9.83470 9.83497 9.83524 9.83551 9.83578 9.83605 9.83632 9.83659 9.83686 9.83713 9.83740 9.83768 9.83795 9.83822 9.83849 9.83876 9.83903 9.83930 9.83957 9.83984 9.84011 9.84038 9.84065 9.84092 9.84119 9.84146 9.84173 9.84200 9.84227 9.84254 9.84280 9.84307 9.84334 9.84361 9.84388 9.84415 9.84442 9.84469 9.84496 9.84523 L. Cotgf. 27 27, 27 28 27 27 27 28 27 27 27 27 27 28 27 27 27 27 27 27 28 27 27 27 27 27 27 27 27 27 27 28 27 27 27 27 27 27 27 27 27 27 27 27 27 27 27 27 27 27 26 27 27 27 27 27 27 27 27 27 L. Cotg. L. Cos. 0.17101 0.17074 0.17047 0.17020 0.16992 9.91857 9.91849 9.91840 9.91832 9.91823 0.16965 0.16938 0.16911 0.16883 0.16856 9.91815 9.91806 9.91798 9.91789 9.91781 0.16829 0.16802 0.16775 0.16748 0.16720 9.91772 9.91763 9.91755 9.91746 9.91738 0.16693 0.16666 0.16639 0.16612 0.16585 9.91729 9.91720 9.91712 9.91703 9.91695 0.16558 0.16530 0.16503 0.16476 0.16449 9.91686 9.91677 9.91669 9.91660 9.91651 0.16422 0.16395 0.16368 0.16341 0.16314 9.91643 9.91634 9.91625 9.91617 9.91608 0.16287 0.16260 0.16232 0.16205 0.16178 9.91599 9.91591 9.91582 9.91573 9.91565 0.16151 0.16124 0.16097 0.16070 0.16043 9.91556 9.9154? 9.91538 9.91530 9.91521 0.16016 0.15989 0.15962 0.15935 0.15908 9.91512 9.91504 9.91495 9.91486 9.91477 0.15881 0.15854 0.15827 0.15800 0.15773 9.91469 9.91460 9.91451 9.91442 9.91433 0.15746 0.15720 0.15693 0.15666 0.15639 9.91425 9.91416 9.91407 9.91398 9.91389 0.15612 0.15585 0.15558 0.15531 0.15504 9.91381 9.91372 9.91363 9.91354 9.91345 0.15477 9.91336 L.Tang. L. Sin. d. 8 9 8 9 8 9 8 9 8 9 9 8 9 8 9 9 8 9 8 9 9 8 9 9 8 9 9 8 9 9 8 9 9 8 9 9 9 8 9 9 8 9 9 9 8 9 9 9 9 8 9 9 9 9 8 9 9 9 9 9 d. 55 54 53 52 51 50 49 48 47 46 45 44 43 42 41 40 39 38 37 36 35 34 33 32 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 P. P. 28 2.8 3.3 3.7 4.2 4.7 9.3 14.0 18.7 23.3 27 2.7 3.2 3.6 4.1 4.5 9.0 13.5 18.0 22.5 6 7 8 9 10 20 30 40 50 6 7 8 9 10 20 30 40 50 6 7 8 9 10 20 30 40 50 26 2.6 3.0 3.5 3.9 4.3 8.7 13.0 17.3 21.7 13 1.9 2.2 2.5 2.9 3.2 6.3 9.5 12.7 15.8 18 1.8 2.1 2.4 2.7 3.0 6.0 9.0 12.0 15.0 6 7 8 9 10 20 30 40 50 9 0.9 1.1 1.2 1.4 1.5 3.0 4.5 6.0 7.5 0.8 0.9 1.1 1.2 1.3 2.7 4.0 5.3 6.7 P. P. 55 ° f L. Sin. 0 9.75859 1 9.75877 2 9.75895 3 9.75913 4 9.75931 5 9.75949 6 9.75967 7 9.75985 8 9.76003 9 9.76021 10 9.76039 11 9.76057 12 9.76075 13 9.76093 14 9.76111 15 9.76129 16 9.76146 17 9.76164 18 9.76182 19 9.76200 20 9.76218 21 9.76236 22 9.76253 23 9.76271 24 9.76289 25 9.76307 26 9.76324 27 9.76342 28 9.76360 29 9.76378 30 9.76395 31 9.76413 32 9.76431 33 9.76448 34 9.76466 35 9.76484 36 9.76501 37 9.76519 38 9.76537 39 9.76554 40 9.76572 41 9.76590 42 9.76607 43 9.76625 44 9.76642 45 9.76660 46 9.76677 47 9.76695 48 9.76712 49 9.76730 50 9.76747 51 9.76765 52 9.76782 53 9.76800 54 9.76817 55 9.76835 56 9.76852 57 9.76870 58 9.76887 59 9.76904 60 9.76922 L. Cos. LOGARITHMS OF TRIGONOMETRIC FUNCTIONS . 35 ° 527 d. L.Tang. d. c. L. Cotg. 18 18 18 18 18 18 18 18 18 18 18 18 18 18 18 17 18 18 18 18 18 17 18 18 18 17 18 18 18 17 18 18 17 18 18 17 18 18 17 18 18 17 18 17 18 17 18 17 18 17 18 17 18 17 18 17 18 17 17 18 9.84528 9.84550 9.84576 9.84603 9.84630 9.84657 9.84684 9.84711 9.84738 9.84764 9.84791 9.84818 9.84845 9.84872 9.84899 9.84925 9.84952 9.84979 9.85006 9.85033 9.85059 9.85086 9.85113 9.85140 9.85166 9.85193 9.85220 9.85247 9.85273 9.85300 9.85327 9.85354 9.85380 9.85407 9.85434 9.85460 9.85487 9.85514 9.85540 9.85567 9.85594 9.85620 9.85647 9.85674 9.85700 9.85727 9.85754 9.85780 9.85807 9.85834 9.85860 9.85887 9.85913 9.85940 9.85967 9.85993 9.86020 9.86046 9.86073 9.86100 9.86126 d. L. Cotg. 27 26 27 27 27 27 27 27 26 27 27 27 27 27 26 27 27 27 27 26 27 27 27 26 27 27 27 26 27 27 27 26 27 27 26 27 27 26 27 27 26 27 27 26 27 27 26 27 27 26 27 26 27 27 26 27 26 27 27 26 0.15477 0.15450 0.15424 0.15397 0.15370 0.15343 0.15316 0.15289 0.15262 0.15236 0.15209 0.15182 0.15155 0.15128 0.15101 0.15075 0.15048 0.15021 0.14994 0.14967 0.14941 0.14914 0.14887 0.14860 0.14834 0.14807 0.14780 0.14753 0.14727 0.14700 L. Cos. 9.91336 9.91328 9.91319 9.91310 9.91301 9.91292 9.91283 9.91274 9.91266 9.91257 9.91248 9.91239 9.91230 9.91221 9.91212 d. 9.91203 9.91194 9.91185 9.91176 9.91167 9.91158 .9.91149 9.91141 9.91132 9.91123 0.14673 0.14646 0.14620 0.14593 0.14566 0.14540 0.14513 0.14486 0.14460 0.14433 0.14406 0.14380 0.14353 0.14326 0.14300 9.91114 9.91105 9.91096 9.91087 9.91078 9.91069 9.91060 9.91051 9.91042 9.91033 9.91023 9.91014 9.91005 9.90996 9.90987 0.14273 0.14246 0.14220 0.14193 0.14166 0.14140 0.14113 0.14087 0.14060 0.14033 0.14007 0.13980 0.13954 0.13927 0.13900 d. c. 0.13874 I L.Tang 9.90978 9.90969 9.90960 9.90951 9.90942 9.90933 9.90924 9.90915 9.90906 9.90896 9.90887 9.90878 9.90869 9.90860 9.90851 9.90842 9.90832 9.90823 9.90814 9.90805 9.90796 L. Sin. 8 9 9 9 9 9 9 8 9 9 9 9 9 9 9 9 9 9 9 9 9 8 9 9 9 9 9 9 9 9 9 9 9 9 10 9 9 9 9 9 9 9 9 9 9 9 9 9 10 9 9 9 9 9 9 10 9 9 9 9 60 59 58 57 56 ^ 55 54 53 52 51 50 49 48 47 46 45 44 43 42 41 40 39 38 37 36 35 34 33 32 31 P. P. 27 26 6 2.7 2.6 7 3.2 3.0 8 3.6 3.5 9 4.1 3.9 10 4.5 4.3 20 9.0 8.7 30 13.5 13.0 40 18.0 17.3 50 22.5 21.7 18 6 1.8 7 2.1 8 2.4 9 2.7 10 3.0 20 6.0 30 9.0 40 12.0 50 15.0 17 1.7 2.0 2.3 2.6 2.8 5.7 8.5 11.3 14.2 10 1.0 1.2 1.3 1.5 1.7 3.3 5.0 6.7 8.3 9 8 6 0.9 0.8 7 1.1 0.9 8 1.2 1.1 9 1.4 1.2 10 1.5 1.3 20 3.0 2.7 30 4.5 4.0 40 6.0 5.3 50 7.5 6.7 P. P. 54 ° 528 LOGARITHMS OF TRIGONOMETRIC FUNCTIONS. 36 ° L. Sin. d. L.Tang. d. c. L. Cotg. L. Cos. d. 0.13874 9.90796 60 0.13847 9.90787 9 59 0.13821 9.90777 10 58 0.13794 9.90768 9 57 0.13768 9.90759 9 q 56 0.13741 9.90750 «7 A 55 0.13715 9.90741 9 54 0.13688 9.90731 10 53 0.13662 9.90722 9 52 0.13635 9.90713 9 q 51 0.13608 9.90704 V -? rv 50 0.13582 9.90694 iO 49 0.13555 9.90685 9 48 0.13529 9.90676 9 47 0.13502 9.90667 9 10 46 0.13476 9.90657 -LV/ A 45 0.13449 9.90648 9 a 44 0.13423 9.90639 9 43 0.13397 9.90630 9 42 0.13370 9.90620 10 q 41 0.13344 9.90611 A 40 0.13317 9.90602 9 1 A 39 0.13291 9.90592 10 38 0.13264 9.90583 9 37 0.13238 9.90574 9 9 36 0.13211 9.90565 35 0.13185 9.90555 10 34 0.13158 9.90546 9 A 33 0.13132 9.90537 9 32 0.13106 9.90527 10 9 31 0.13079 9.90518 30 0.13053 9.90509 9 29 0.13026 9.90499 10 A 28 0.13000 9.90490 9 27 0.12973 9.90480 10 9 26 0.12947 9.90471 25 0.12921 9.90462 9 24 0.12894 9.90452 10 23 0.12868 9.90443 9 22 0.12842 9.90434 9 10 21 0.12815 9.90424 20 0.12789 9.90415 9 19 0.12762 9.90405 10 18 0.12736 9.90396 9 17 0.12710 9.90386 10 9 16 0.12683 9.90377 15 0.12657 9.90368 9 14 0.12631 9.90358 10 13 0.12604 9.90349 9 12 0.12578 9.90339 10 9 11 0.12552 9.90330 10 0.12525 9.90320 10 9 0.12499 9.90311 9 *1 A 8 0.12473 9.90301 10 7 0.12446 9.90292 9 10 6 0.12420 9.90282 5 0.12394 9.90273 9 4 0.12367 9.90263 10 3 0.12341 9.90254 9 2 0.12315 9.90244 10 9 1 0.12289 9.90235 0 L.Tang. L. Sin | d.. / P. P. 20 21 22 23 24 25 26 27 28 29 30 ” 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48' 49 50 51 52 53 54 55 56 57 58 59 9.76922 9.76939 9.76957 9.76974 9.76991 9.77009 9.77026 9.77043 9.77061 9.77078 9.77095 9.77112 9.77130 9.77147 9.77164 9.77181 9.77199 9.77216 9.77233 9.77250 9.77268 9.77285 9.77302 9.77319 9.77336 9.77353 9.77370 9.77387 9.77405 9.7/422 9.77439 9.77456 9.77473 9.77490 977507 9.77524 9.77541 9.77558 9.77575 9.77592 9.77609 9.77626 9.77643 9.77660 9.77677 9.77694 9.77711 9.77728 9.77744 9.77761 9.77778 9.77795 9.77812 9.77829 9.77846 9.77862 9.77879 9.77896 9.77913 9.77930 60 9.77946 L. Cos. 17 18 17 17 18 17 17 18 17 17 17 18 17 17 17 18 17 17 17 18 17 17 17 17 17 17 17 18 17 17 17 17 17 17 17 17 17 17 17 17 17 17 17 17 17 17 17 16 17 17 17 17 17 17 16 17 17 17 17 16 9.86126 9.86153 9.86179 9.86206 9.86232 9.86259 9.86285 9.86312 9.86338 9.86365 9.86392 9.86418 9.86445 9.86471 9.86498 9.86524 9.86551 9.86577 9.86603 9.86630 9.86656 9.86683 9.86709 9.86736 9. 86762 9.86789 9.86815 9.86842 9.86868 9.86894 9.86921 9=86947 9.86974 9.87000 9.87027 9.87053 9.87079 9.87106 9.87132 9.87158 9.87185 9.87211 9.87238 9.87264 9.87290 9.87317 9.87343 9.87369 9.87396 9.87422 9.87448 9.87475 9.87501 9.87527 9.87554 9.87580 9.87606 9.87633 9.87659 9.87685 9.87711 27 26 27 26 27 26 27 26 27 27 26 27 26 27 26 27 26 26 27 26 27 26 27 26 27 26 27 26 26 27 26 27 26 27 26 26 27 26 26 27 26 27 26 26 27 26 26 27 26 26 27 26 26 27 26 26 27 26 26 26 27 2.7 3.2 3.6 4.1 4.5 9.0 13.5 18.0 22.5 26 2.6 3.0 3.5 3.9 4.3 8.7 13.0 17.3 21.7 18 1.8 2.1 2.4 2.7 3.0 6.0 9.0 40 12.0 50 i 15.0 6 7 8 9 10 20 30 40 50 17 1.7 2.0 2.3 2.6 2.8 5.7 8.5 11.3 14.2 16 1.6 1.9 2.1 2.4 2.7 5.3 8.0 10.7 13.3 iO 1.0 1.2 1.3 1.5 1.7 3.3 5.0 6.7 8.3 9 0.9 1.1 1.2 1.4 1.5 3.0 4.5 6.0 7.5 d. L. Cotg, d. c. P. P. 53 c logarithms of trigonometric functions. 529 / I L. Sin. c 0 9.77946 n 1 9.77963 2 9.77980 } 3 9.77997 4 9.78013 5 9.78030 . 6 9.78047 ] 7 9.78063 ; 8 9.78080 : 9 9.78097 : 10 9.78113 ; 11 9.78130 12 9.78147 13 9.78163 14 9.78180 15 9.78197 16 1 9.78213 17 9.78230 18 9.78246 19 9.78263 20 9.78280 21 9.78296 22 9.78313 23 9.78329 24 9.78346 25 9.78362 26 9.78379 27 9.78395 28 9.78412 29 ; 9.78428 30 9.78445 31 9.78461 32 9.78478 33 9.78494 34 1 9.78510 35 9.78527 36 9.78543 37 9.78560 38 9.78576 39 9.78592 40 9.78609 41 9.78625 42 9.78642 43 9.78658 44 9.78674 1 45 9.78691" 46 9.78707 47 9.78723 48 9.78739 49 9.78756 50 | 9.78772 51 9.78788 52 9.78805 53 9.78821 54 9.78837 55 9.78853 56 9.78869 57 9.78886 58 . 9.78902 59 i 9.78918 60 i 9.78934 16 17 16 17 17 16 17 16 17 16 17 16 17 16 17 16 17 16 16 17 16 17 16 16 17 16 17 16 16 17 16 16 16 17 16 d. L.Tang. d. 9.87711 r 9.87738 i 9.87764 i 9.87790 ; 9.87817 t 9.87843 J 9.87869 ; 9.87895 ; 9.87922 ; 9.87948 ; 9.87974 i 9.88000 ; 9.88027 ; 9.88053 ; 9.88079 ; 9.88105 9.88131 9.88158 9.88184 9.88210 9.88236 9.88262 9.88289 9.88315 9.88341 9.88367 9.88393 9.88420 9.88446 9.88472 9.88498 9.88524 9.88550 9.88577 9.88603 9.88629 9.88655 9.88681 9.88707 9.88733 9.88759 9.88786 9.88812 9.88838 9.88864 9.88890 9.88916 9.88942 9.88968 9.88994 9.89020 9.89046 9.89073 ' 9.89099 1 9.89125 ’ 9.89151 » 9.89177 ' 9.89203 > 9.89229 > 9.89255 3 9.89281 L. Cotg .c. I j. Cotg. ] L. Cos. d. P. P. 0.12289 9.90235 i 60 27- 0.12262 9.90225 10 59 26 0.12236 9.90216 9 58 27 26 0.12210 9.90206 10 57 6 2.7 27 0.12183 9.90197 9 10 56 7 3.2 26 0.12157 9.90187 55 8 3.6 26 0.12131 9.90178 9 54 9 4.1 26 0.12105 9.90168 10 53 10 4.5 27 0.12078 9.90159 9 52 20 9.0 26 0.12052 9.90149 10 10 - 51 30 13.5 2b 0.12026 9.90139 50 40 18.0 26 0.12000 9.90130 9 49 50 22.5 27 0.11973 9.90120 10 48 26 0.11947 9.90111 9 47 26 0.11921 9.90101 10 10 46 26 Zb 0.11895 9.90091 45 6 2.6 26 0.11869 9.90082 9 44 7 3.0 27 0.11842 9.90072 10 43 8 3.5 26 0.11816 9.90063 9 42 9 3.9 26 0.11790 9.90053 10 41 10 4.3 26 10 20 0.11764 9.90043 40 o ./ 1 o A 26 0.11738 9.90034 9 39 30 13.0 27 0.11711 9.90024 10 38 40 17.3 HI *7 j 26 0.11685 9.90014 10 37 50 21.7 26 26 0.11659 9.90005 9 10 36 N 0.11633 9.89995 35 26 0.11607 9.89985 10 34 17 27 0.11580 9.89976 9 33 6 1.7 26 0.11554 9.89966 10 32 7 2.0 26 0.11528 9.89956 10 q 31 8 Q 2.3 9 fi Zo 0.11502 9.89947 U -1 A 30 10 2.8 26 0.11476 9.89937 10 29 20 5.7 26 0.11450 9.89927 10 28 30 8.5 27 0.11423 9.89918 9 27 40 11.3 26 O a 0.11397 9.89908 10 10 26 50 14.2 ZO 0.11371 9.89898 25 26 0.11345 9.89888 10 24 .26 0.11319 9.89879 9 23 ic 26 0.11293 9.89869 10 22 o lb 1 A 26 OA 0.11267 9.89859 10 10 21 b 7 i.b 1.9 Zb 0.11241 9.89849 20 8 2.1 27 0.11214 9.89840 9 19 9 2.4 26 0.11188 9.89830 10 18 10 2.7 26 0.11162 9.89820 10 17 20 5.3 26 OA 0.11136 9.89810 10 9 16 30 8.0 Zb 0.11110 9.89801 15 40 10.7 26 0.11084 9.89791 10 14 50 i 13.3 26 0.11058 9.89781 10 13 26 0.11032 9.89771 10 12 26 OA 0.11006 9.89761 10 Q 11 10 9 Zb 0.10980 9.89752" -f A 10 6 1.0 0.9 26 0.10954 9.89742 10 9 7 1.2 1.1 27 0.10927 9.89732 10 8 8 1.3 1.2 26 0.10901 9.89722 10 7 9 1.5 1.4 26 OA 0.10875 9.89712 10 ' 10 6 10 1.7 1.5 ZO 0.10849 9.89702 5 20 3.3 3.0 26 0.10823 9.89693 i 9 4 30 5.0 4.5 26 0.10797 9.89683 1 K 3 40 6.7 6.0 26 0.10771 9.89673 ; In 2 50 8.3 7.5 26 o Ct 0.10745 > 9.89663 5 10 1 ZO 0.10719 1 9.8965* i 10 0 d. c . L.Tang f. L. Sin . d. / P. P. 52 ° 530 LOGARITHMS OF TRIGONOMETRIC FUNCTIONS . 38 ° / L. Sin. d. L.Tang. d. c. L. Cotg. L. Cos. d. P. P. 0 1 2 3 4 9.78934 9.78950 9.78967 9.78983 9.78999 16 17 16 16 16 16 16 16 16 16 9.89281 9.89307 9.89333 9.89359 9.89385 26 26 26 26 26 26 26 26 26 26 0.10719 0.10693 0.10667 0.10641 0.10615 9.89653 9.89643 9.89633 9.89624 9.89614 10 10 9 ! 10 j 10 10 : io ! io ! 10 10 60 59 58 57 56 26 6 2.6 7 3.0 8 I 3.5 9 j 3.9 10 4.3 20 8.7 30 13.0 25 2.5 2.9 I 3.3 1 3.8 ! 4.2 8.3 12.5 5 6 7 8 9 9.79015 9.79031 9.79047 9.79063 9.79079 9.80411 9.89437 9.89463 9.89489 9.89515 0.10589 0.10563 0.10537 0.10511 0.10485 9.89604 9.89594 9.89584 9.89574 9.89564 55 54 53 52 51 10 9.79095 9.89541 0.10459 9.89554 50 40 17.3 16.7 11 9.79111 16 9.89567 26 0.10433 9.89544 10 49 50 | 21.7 20.S 12 9.79128 17 9.89593 26 0.10407 9.89534 ! 10 48 13 9.79144 16 9.89619 26 0.10381 9.89524 1 10 47 14 9.79160 16 16 9.89645 26 OA 0.10355 9.89514 10 10 46 17 15 9.79176 9.89671 0.10329 9.89504 45 6 17 16 9.79192 16 9.89697 26 0.10303 9.89495 9 44 7 ? 5 > 0 17 9.79208 16 9.89723 26 0.10277 9.89485 ! 10 43 8 2.3 18 9.79224 16 9.89749 26 0.10251 9.S9475 i 10 42 9 2.6 19 9.79240 16 16 9.89775 26 26 0.10225 9.89465 1 10 ! 10 41 io *: >.8 20 9.79256 9.89801 0.10199 9.89455 40 20 ! 5.7 21 9.79272 16 9.89827 26 0.10173 9.S9445 1 10 39 30 | 8.5 22 9.79288 16 9.89S53 26 0.10147 9.89435 j 10 38 40 j 11.3 23 9.79304 16 9.89879 26 0.10121 9.89425 i 10 37 50 j 14.2 24 9.79319 15 16 9.89905 26 26 0.10095 9.89415 I 10 10 36 25 9.79335 9.89931 0.10069 9.89405 35 26 9.79351 16 9.89957 26 0.10043 9.89395 10 34 16 15 27 9.79367 16 9.89983 26 0.10017 9.89385 10 33 6 1.6 1.5 28 9.79383 16 9.90009 26 0.09991 9.89375 10 32 7 1.9 1.8 29 9.79399 16 9.90035 I 26 j 0.09965 9.89364 ! 11 31 8 2.1 2.0 16 1 Ofx ! 10 30 9.79415 9.90061 zo ! 0.09939 9.89354 30 9 2.4 | 2.3 31 9.79431 ! 16 9.90086 25 0.09914 9.S9344 ! 10 29 10 2.7 : 2.5 32 9.79447 ! 16 9.90112 26 i 0.09888 9.89334 j 10 28 20 i o.3 ; 5.0 33 9.79463 16 9.90138 j 26 0.09862 9.89324 ! 10 27 30 8.0 * 7.5 34 9.79478 15 16 9.90164 ! 26 26 i 0.09836 9.89314 j 10 10 26 40 10.7 50 , 13.3 | 10.0 12.5 35 9.79494 1 9.90190 | i 0.09810 9.89304 25 36 9.79510 1 16 9.90216 ! 26 ! 0.09784 9.89294 10 24 37 9.79526 16 9.90242 1 1 0.09758 9.89284 10 23 38 9.79542 16 9.90268 | 26 | 0.09732 9.89274 10 22 II 39 9.79558 16 9.90294 | 26 0.09706 9.89264 10 21 6 1.1 15 10 T 1 Q 40 9.79573 | 9.90320 j zo 0.09680 9.89254 20 i j 1.0 <2 1 ^ 41 9.79589 | 16 9.90346 26 0.09654 9.89244 ! 10 19 O 1.0 Q 1 7 42 9.79605 16 9.90371 I 25 ! 0.09629 9.89233 11 18 St j A. / 10 1 ^ 43 9.79621 16 9.90397 | 26 0.09603 9.89223 10 17 1U ; J..O 20 ^ 7 44 9.79636 15 16 9.90423 | 26 •>A 0.09577 9.89213 ! 10 10 16 _u o. / 30 ' 5.5 45 9.79652 ! 9.90449 j ZD 0.09551 9.89203 | 15 40 7. 3 46 9.79668 16 9.90475 26 0.09525 9.89193 10 14 50 j 9. o 47 9.79684 16 9.90501 26 0.09499 9.89183 10 13 48 9.79699 | 15 9.90527 26 0.09473 9.89173 i 10 12 49 9.79715 16 16 9.90553 26 j 25 | 0.09447 9.89162 I 11 10 11 10 9 50 9.79731 i 9.90578 0.09422 9.89152 10 6 1 1.0 0.9 51 9.79746 1 15 9.90604 26 i 0.09396 9.89142 i 10 9 7 1.2 | 1.1 52 9.79762 ! 16 9.90630 26 0.09370 9.89132 i 10 8 8 1 1.3 1.2 53 9.79778 16 9.90656 26 i 0.09344 9.89122 i 10 7 9 1.5 1.4 54 9.79793 | 15 16 9.90682 | 26 26 0.09318 9.89112 10 11 6 10 j 1.7 1.5 55 9.79809 i 9.90708 0.09292 9.89101 5 20 ! 3.3 3.0 56 9.79825 1 16 9.90734 26 0.09266 9.89091 i 10 4 30 1 5.0 4.5 57 9.79840 | 15 9.90759 ! 25 0.09241 9.S9081 10 3 40 6.7 6.0 58 9.79856 i 16 9.90785 j 26 0.09215 9.89071 10 2 50 | 8.3 7.6 59 9.79872 ! 16 15 9.90811 1 26 . 0.09189 9.89060 ! 11 10 1 60 9.79887 9.90837 — U , 0.09163 9.89050 0 L. Cos. d. L. Cotg. d. c. L.Tang. L. Sin. d. / P. P. 51 ° LOGARITHMS OF TRIGONOMETRIC FUNCTIONS 531 / L. Sin. 0 9.79887 1 9.79903 2 9.79918 3 9.79934 4 9.79950 5 9.79965 6 9.79981 7 9.79996 8 9.80012 9 9.80027 10 9.80043 11 9.80058 12 9.80074 13 9.80089 14 9.80105 15 9.80120 16 9.80136 17 9.80151 18 9 V 80166 19 9.80182 20 9.80197 21 9.80213 22 9.80228 23 9.80244 24 9.80259 25 9.80274 26 9.80290 27 9.8G305 28 9.80320 29 9.80336 30 9.80351 31 9.80366 32 9.80382 33 9.80397 34 9.80412 35 9.80428 36 9.80443 37 9.80458 38 9.80473 39 9.80489 40 9.80504 41 9.80519 42 9.80534 43 9.80550 44 9.80565 45 9.80580 46 9.80595 47 9.80610 48 9.80625 49 9.80641 50 9.80656 51 9.80671 52 9.80686 53 9.80701 54 9.80716 55 9.80731 56 9.80746 57 9.80762 58 9.80777 59 9.80792 60 9.80807 L. Cos. d. 16 15 16 16 15 16 15 16 15 16 15 16 15 16 15 16 15 15 16 15 16 15 16 15 15 16 15 15 16 15 15 16 15 15 16 15 15 15 16 15 15 15 16 15 15 15 15 15 16 15 15 15 15 15 15 15 16 15 15 L.Tang. d “9790837 9.90863 9.90889 9.90914 9.90940 9.90966 9.90992 9.91018 9.91043 9.91069 9.91095 9.91121 9.91147 9.91172 9.91198 9.91224 9.91250 9.91276 9.91301 9.91327 9.91353 9.91379 9.91404 9.91430 9.91456 9.91482 9.91507 9.91533 9.91559 9.91585 9.91610 9.91636 9.91662 9.91688 9.91713 9.91739 9.91765 9.91791 9.91816 9.91842 9.91868 9.91893 9.91919 9.91945 9.91971 9.91996 9.92022 9.92048 9.92073 9.92099 9.92125 9.92150 9.92176 9.92202 9.92227 9.92253 9.92279 9.92304 9.92330 9.92356 9.92381 L. Cotg. 26 26 25 26 26 26 26 25 26 26 26 26 25 26 26 26 26 25 26 26 26 25 26 26 26 25 26 26 26 25 26 26 26 25 . 26 26 26 25 26 26 25 26 26 26 25 26 26 25 26 26 25 26 26 25 26 26 25 26 26 25 L. Cotg. L. Cos. c 0.09163 " 9.89050 . 0.09137 9.89040 ] 0.09111 9.89030 } 0.09086 9.89020 } 0.09060 9.89009 1 0.09034 9.88999 , 0.09008 9.88989 0.08982 9.88978 0.08957 9.88968 0.08931 9.88958 0.08905 9.88948 . 0.08879 9.88937 3 0.08853 9.88927 : 0.08828 9.88917 : 0.08802 9.8^906 : 0.08776 9.88896 ! 0.08750 9.88886 : 0.08724 9.88875 : 0.08699 9.88865 : 0.08673 9.88855 0.08647 9.88844 0.08621 9.88834 0.08596 9.88824 0.08570 9.88813 0.08544 9.88803 0.08518 9.88793 0.08493 9.88782 0.08467 9.88772 0.08441 9.88761 0.08415 9.88751 0.08390 9.88741 0.08364 9.88730 0.08338 9.88720 0.08312 9.88709 0.08287 9.88699 0.08261 9.88688 0.08235 9.88678 0.08209 9.88668 0.08184 9.88657 0.08158 9.88647 0.08132 9.88636 0.08107 9.88626 0.08081 9.88615 0.08055 9.88605 0.08029 9.88594 0.08004 9.88584 0.07978 9.88573 0.07952 9.88563 0.07927 9.88552 0.07901 9.88542 0.07875 9.88531 0.07850 9.88521 0.07824 9.88510 0.07798 9.88499 0.07773 9.88489 0.07747 9.88478 0.07721 9.88468 0.07696 9.88457 0.07670 9.88447 0.07644 9.88436 0.07619 9.88425 3. L.Tang . L. Sin. 60 59 58 57 _56 55 54 53 52 51 50 49 48 47 46 P. P. 10 10 11 10 10 11 10 10 11 10 11 10 10 11 10 11 10 11 10 10 11 10 11 10 11 10 11 10 11 10 11 10 11 10 11 11 10 11 10 11 10 11 11 d. 35 34 33 32 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 7 8 9 10 20 30 40 50 6 7 8 9 10 20 30 40 50 6 7 8 9 10 20 30 40 50 26 2.6 3.0 3.5 3.9 4.3 8.7 13.0 17.3 21.7 25 2.5 2.9 3.3 3.8 4.2 8.3 12.5 16.7 20.8 16 1.6 1.9 2.1 2.4 2.7 5.3 8.0 10.7 13.3 6 7 8 9 10 20 30 40 50 15 1.5 1.8 2.0 2.3 2.5 5.0 7.5 10.0 12.5 6 7 8 9 10 20 30 40 50 II 1.1 1.3 1.5 1.7 1.8 3.7 5.5 7.3 9.2 10 1.0 1.2 1.3 1.5 1.7 3.3 5.0 6.7 8.3 P. P. 50 ° 532 LOGARITHMS OF TRIGONOMETRIC FUNCTIONS, 40 ° / L. Sin. d. L.Tang. d. c. L. Cotg. L. Cos. d. P. P. 0 1 2 3 4 9.80807 9.80822 9.80837 9.80852 9.80867 15 15 15 15 15 15 15 15 15 15 15 15 15 15 15 15 14 . 15 15 15 15 15 15 15 14 15 15 15 15 14 15 15 15 15 14 15 15 14 15 15 15 14 15 15 14 15 15 14 15 15 14 15 14 15 15 14 15 14 15 14 9.92381 9.92407 9.92433 9.92458 9.92484 26 26 25 26 26 25 26 26 25 26 25 26 26 25 26 26 25 26 25 26 26 25 26 25 26 26 25 26 25 26 25 26 26 25 26 25 26 25 26 26 25 26 25 26 25 26 25 26 26 25 26 25 26 25 26 25 26 25 26 25 0.07619 0.07593 0.07567 0.07542 0.07516 9.88425 9.88415 9.88404 9.88394 9.88383 10 11 10 11 11 10 11 11 10 11 11 10 11 11 10 11 11 10 11 11 11 10 11 11 11 10 11 11 11 10 11 11 11 11 10 11 11 11 11 11 11 10 11 11 11 11 11 11 11 11 10 11 11 11 11 11 11 11 11 11 60 59 58 57 56 26 6 2.6 7 3.0 8 3.5 9 3.9 10 4.3 20 8.7 30 13.0 40 17.3 50 21.7 25 6 2.5 7 2.9 8 3.3 9 3.8 10 4.2 20 8.3 ! 30 12.5 40 16.7 50 20.8 15 6 1.5 | 7 1.8 8 2.0 9 2.3 10 2.5 20 5.0 30 7.5 40 10.0 50 12.5 14 ! 6 1.4 7 1.6 8 1.9 9 2.1 10 2.3 20’ 4.7 30 7.0 40 9.3 50 11.7 II 10 6 1.1 1.0 7 1.3 1.2 8 1.5 1.3 9 1.7 1.5 10 1.8 1.7 20 3.7 3.3 j 30 5.5 5.0 40 7.3 6.7 50 9.2 8.3 5 6 7 8 9 9.80882 9.80897 9.80912 9.80927 9.80942 9.92510 9.92535 9.92561 9.92587 9.92612 0.07490 0.07465 0.07439 0.(57413 0.07388 9.88372 9.88362 9.88351 9.88340 9.88330 55 54 53 52 51 10 11 12 13 14 9.80957 9.80972 9.80987 9.81002 9.81017 9.92638 9.92663 9.92689 9.92715 9.92740 0.07362 0.07337 0.07311 0.07285 0.07260 9.88319 9.88308 9.88298 9.88287 9.88276 50 49 48 47 46 15 16 17 18 19 9.81032 9.81047 9.81061 9.81076 9.81091 9.92766 9.92792 9.92817 9.92843 9.92868 0.07234 0.07208 0.07183 0.07157 0.07132 9.88266 9.88255 9.88244 9.88234 9.88223 45 44 43 42 41 20 21 22 23 24 9.81106 9.81121 9.81136 9.81151 9.81166 9.92894 9.92920 9.92945 9.92971 9.92996 0.07106 0.07080 0.07055 0.07029 0.07004 9.88212 9.88201 9.88191 9.88180 9.88169 40 39 38 37 36 25 26 27 28 29 9.81180 9.81195 9.81210 9.81225 9.81240 9.93022 9.93048 9.93073 9.93099 9.93124 0.06978 0.06952 0.06927 0.06901 0.06876 9.88158 9.88148 9.88137 9.88126 9.88115 35 34 33 32 31 30 31 32 33 34 9.81254 9.81269 9.81284 9.81299 9.81314 9.93150 9.93175 9.93201 9.93227 9.93252 0.06850 0.06825 0.06799 0.06773 0.06748 9.88105 9.88094 9.88083 9.88072 9.88061 30 29 28 27 26 35 36 37 38 39 9.81328 9.81343 9.81358 9.81372 9.81387 9.93278 9.93303 9.93329 9.93354 9.93380 0.06722 0.06697 0.06671 0.06646 0.06620 9.88051 9.88040 9.88029 9.88018 9.88007 25 24 23 22 21 40 41 42 43 44 9.81402 9.81417 9.81431 9.81446 9.81461 9.93406 9.93431 9.93457 9.93482 9.93508 0.06594 0.06569 0.06543 0.06518 0.06492 9.87996 9.87985 9.87975 9.87964 9.87953 20 19 18 17 16 45 46 47 48 49 9.81475 9.81490 9.81505 9.81519 9.81534 9.93533 9.93559 9.93584 9.93610 9.93636 0.06467 0.06441 0.06416 0.06390 0.06364 9.87942 9.87931 9.87920 9.87909 9.87898 15 14 13 12 11 50 51 1 52 53 54 9.81549 9.81563 9.81578 9.81592 9.81607 9.93661 9.93687 9.93712 9.93738 9.93763 0.06339 0.06313 0.06288 0.06262 0.06237 9.87887 9.87877 9.87866 9.87855 9.87844 10 9 8 7 6 55 56 57 58 59 60 9.81622 9.81636 9.81651 9.81665 9.81680 9.93789 9.93814 9.93840 9.93865 9.93891 0.06211 0.06186 0.06160 0.06135 0.06109 9.87833 9.87822 9.87811 9.87800 9.87789 5 4 3 2 1 9.81694 9.93916 0.06084 9.87778 0 L. Cos. ~~A. L. Cotg. d. c. L.Tang. L. Sin. d. / P. P. 49 ° 1 LOGARITHMS OF TRIGONOMETRIC FUNCTIONS. 533 / L. Sin. 0 9.81694 1 9.81709 2 9.81723 3 9.81738 4 9.81752 5 9.81767 6 9.81781 7 9.81796 8 9.81810 9 9.81825 10 9.81839 11 9.81854 12 9.81868 13 9.81882 14 9.81897 15 9.81911 16 9.81926 17 9.81940 18 9.81955 19 9.81969 20 9.81983 21 9.81998 22 9.82012 23 9.82026 24 9.82041 25 9.82055 26 9.82069 27 9.82084 28 9.82098 29 9.82112 30 9.82126 31 9.82141 32 9.82155 33 9.82169 34 9.82184 35 9.82198 36 9.82212 37 9.82226 38 9.82240 39 9.82255 40 9.82269 41 9.82283 42 9.82297 43 9.82311 44 9.82326 45 9.82340 46 9.82354 47 9.82368 48 9.82382 49 9.82396 50 9.82410 51 9.82424 52 9.82439 53 9.82453 54 9.82467 55 9.82481 56 9.82495 57 9.82509 58 9.82523 59 9.82537 60 9.82551 L. Cos. d. L.Tang. 15 14 15 14 15 14 15 14 15 14 15 14 14 15 14 15 14 15 14 14 15 14 14 15 14 14 15 14 14 14 15 14 14 15 14 14 14 14 15 14 14 14 14 15 14 14 14 14 14 14 14 15 14 14 14 14 14 14 14 14 9.93916 9.93942 9.93967 9.93993 9.94018 9.94044 9.94069 9.94095 9.94120 9.94146 9.94171 9.94197 9.94222 9.94248 9.94273 9.94299 9.94324 9.94350 9.94375 9.94401 9.94426 9.94452 9.94477 9.94503 9.94528 9.94554 9.94579 9.94604 9.94630 9.94655 9.94681 9.94706 9.94732 5.94757 9.94783 d.c. J L. Cotg. L. Cos. d. 0.06084 9.87778 60 26 0.06058 9.87767 11 59 25 0.06033 9.87756 11 58 26 0.06007 9.87745 11 57 25 0.05982 9.87734 11 11 56 2b 0.05956 9.87723 55 25 0.05931 9.87712 11 54 26 0.05905 9.87701 11 53 25 0.05880 9.87690 11 52 26 0.05854 9.87679 11 11 51 Zo 0.05829 9.87668 50 26 0.05803 9.87657 11 49 25 0.05778 9.87646 11 48 26 0.05752 9.87635 11 47 25 26 0.05727 9.87624 11 11 46 0.05701 9.87613 45 25 0.05676 9.87601 12 44 26 0.05650 9.87590 11 43 25 0.05625 9.87579 11 42 26 25 0.65599 9.87568 11 41 0.05574 9.87557 -LX 1 1 40 26 0.05548 9.87546 11 39 25 0.05523 9.87535 11 38 26 0.05497 9.87524 11 37 25 0.05472 9.87513 11 12 36 Zo 0.05446 9.87501 35 25 0.05421 9.87490 11 34 25 0.05396 9.87479 11 33 26 0.05370 9.87468 11 32 25 0.05345 9.87457 11 11 1 o 31 ZO 0.05319 9.87446 30 25 0.05294 9.87434 12 29 26 0.05268 9.87423 11 28 25 0.05243 9.87412 11 27 26 - 25 0.05217 9.87401 11 11 1 o 26 0.05192 9.87390 25 26 0.05166 9.87378 12 24 i 25 0.05141 9.87367 11 1 1 23 25 0.05116 9.87356 11 22 i 1 0.05090 9.87345 11 11 1 o 21 > ^ 0.05065 9.87334 20 26 0.05039 9.87322 12 19 i 25 0.05014 9.87311 11 18 » 26 0.04988 9.87300 1] 17 r 25 0.04963 9.87288 12 11 16 > 25 0.04938 9.87277 15 i 26 0.04912 9.87266 11 14 > 25 0.04887 9.87255 11 1 o 13 > It 0.04861 9.87243 12 12 1 26 0.04836 9.87232 11 11 11 ) It 0.04810 9.87221 1 o 10 0.04785 9.87209 12 i -| 9 ) 25 0.04760 9.87198 11 8 5 It 0.04734 9.87187 11 7 1 26 0.04709 9.87175 12, 11 6 7 it 0.04683 9.87164 5 2 25 0.04658 9.87153 11 4 3 ?6 0.04632 9.87141 12 3 i 25 0.04607 9.87130 11 2 8 25 0.04582 9.87119 11 - 12 , 1 4 26 0.04556 9.87107 0 d. c. L.Tang . L. Sin. d. / P. P. 6 7 8 9 10 20 30 40 50 6 7 8 9 10 20 30 40 50 6 7 8 9 10 20 30 40 50 26 2.6 3.0 3.5 3.9 4.3 8.7 13.0 17.3 21.7 25 2.5 2.9 3.3 3.8 4.2 8.3 12.5 16.7 20.8 15 1.5 1 8 2.0 2.3 2.5 5.0 7.5 10.0 12.5 6 7 8 9 10 20 30 40 50 14 1.4 1.6 1.9 2:1 2.3 4.7 7.0 9.3 11.7 6 7 8 9 10 20 30 40 50 12 1.2 1.4 1.6 1.8 2.0 4.0 6.0 8.0 10.0 P. P. II 1.1 1.3 1.5 1.7 1.8 3.7 5.5 7.3 9.2 48 c 534 LOGARITHMS OF TRIGONOMETRIC FUNCTIONS. 42 ° / L. Sin. d. L.Tang. d. c. L. Cotg. L. Cos. d. P . P. 0 9.82551 9.95444 0.04556 9.87107 60 1 9.82565 14 9.95469 2 5 0.04531 9.87096 11 59 2 9.82579 14 9.95495 26 0.04505 9.87085 11 58 0 c 3 9.82593 14 9.95520 25 0.04480 9.87073 12 57 R CO O R 4 9.82607 14 1 A 9.95545 25 26 0.04455 9.87062 11 12 56 0 7 Z.D 3.0 5 9.82621 9.95571 0.04429 ■9.87050 55 8 3.5 6 9.82635 14 9.95596 25 0.04404 9.87039 11 54 9 3.9 7 9.82649 14 9,95622 26 0.0437 0.04353 9.87016 12 52 20 8.7 9 9.82677 14 r a 9.95672 25 26 0.04328 9.87005 11 12 51 30 13.0 10 9.82691 9.95698 0.04302 9.86993 50 40 17.3 11 9.82705 14 9.95723 25 0.04277 9.86982 11 49 50 21.7 12 9.82719 14 9.95748 25 0.04252 9.86970 12 48 13 9.82733 14 9.95774 26 0.04226 9.86959 11 47 14 9.82747 14 1, A 9.95799 25 0.04201 9.86947 12 11 46 25 15 9.82761 9.95825 0.04175 9.86936 45 6 2.5 16 9.82775 14 9.95850 25 0.04150 9.86924 12 44 7 2.9 17 - 9.82788 13 9.95875 25 0.04125 9.86913 11 43 8 3.3 18 9.82802 14 9.95901 26 0.04099 9.86902 11 42 9 3.8 19 9.82816 14 9.95926 25 0.04074 9.86890 12 41 10 4.2 26 11 20 9.82830 9.95952 0.04048 9.86879 40 ZO S.3 21 9.82844 14 9.95977 25 0.04023 9.86867 12 39 30 12.5 22 9.82858 14 9.96002 25 0.03998 9.86855 12 38 40 16.7 23 9.82872 14 9.96028 26 0.03972 9.86844 11 37 50 20.8 24 9.82885 13 14 9.96053 25 25 0.03947 9.86832 12 11 36 25 9.82899 9.96078 0.03922 9.86821 35 26 9.82913 14 9.96104 26 0.03896 9.86809 12 34 14 27 9.82927 14 9.96129 25 0.03871 9.86798 11 33 6 1.4 28 9.82941 14 9.96155 26 0.03845 9.86786 12 32 7 1.6 29 9.82955 14 iq 9.96180 25 25 0.03820 9.86775 11 12 31 8 1.9 O 1 30 9.82968 AO 9.96205 0.03795 9.86763 30 i n Z.A 9 ^ 31 9.82982 14 9.96231 26 0.03769 9.86752 11 29 ±u on A 7 32 9.82996 14 9.96256 25 0.03744 9.86740 12 28 4k. / 7 0 33 9.83010 14 9.96281 25 0.03719 9.86728 12 27 ou d.0 / .u Q ^ 34 9.83023 13 14 9.96307 26 25 OK 0.03693 9.86717 11 19 26 50 t/.O 11.7 35 9.83037 Art i a 9.96332 0.03668 9.86705 A<£ 25 36 9.83051 14 9.96357 25 0.03643 9.86694 11 24 37 9.83065 14 9.96383 26 0.03617 9.86682 12 23 38 9.83078 13 9.96408 25 0.03592 9.86670 12 22 13 39 9.83092 14 14 9.96433 25 26 0.03567 9.86659 11 12 21 6 7 1.3 1.5 40 9.83106 9.96459 0.03541- 9.86647 20 8 L7 11 9.83120 14 9.96484 25 0.03516 9.86635 12 19 9 2.0 12 9.83133 13 9.96510 26 0.03490 9.86624 11 18 10 2.2 43 9.83147 14 9.96535 25 0.03465 9.86612 12 17 20 4.3 44 9.83161 14 -iq 9.96560 25 26 0.03440 9.86600 12 11 16 30 6.5 45 9.83174 _LO 9.96586 0.03414 9.86589 15 40 8.7 46 9.83188 14 9.96611 25 0.03389 9.86577 12 14 50 10.8 47 9.83202 14 9.96636 25 0.03364 9.86565 12 13 48 9.83215 13 9.96662 26 0.03338 9.86554 11 12 49 9.83229 14 IQ 9.96687 25 25 0.03313 9.86542 12 19 11 12 II 50 9.83242 i-O i a 9.96712 0.03288 9.86530 AZi 10 6 1.2 1.1 51 9.83256 14 9.96738 26 0.03262 9.86518 12 9 7 1.4 1.3 52 9.83270 14 9.96763 25 0.03237 9.86507 11 8 8 1.6 1.5 53 9.83283 13 9.96788 25 0.03212 9.86495 12 7 9 1.8 1.7 54 9.83297 14 13 9.96814 26 25 0.03186 9.86483 12 11 6 10 2.0 1.8 55 9.83310 9.96839 0.03161 9.86472 5 20 4.0 3.7 56 9.83324 14 9.96864 25 0.03136 9.86460 12 4 30 6.0 5.5 57 9.83338 14 9.96890 26 0.03110 9.86448 12 3 40 8.0 7.3 58 9.83351 13 9.96915 25 0.03085 9.86436 12 2 50 10.0 9.2 59 9.83365 14 IQ 9.96940 25 26 0.03060 9.86425 11 12 1 60 9.83378 AO 9.96966 0.03034 9.86413 0 L. Cos. d. L. Cotg. d. c. L.Tang. L. Sin. d. / P. P. 47 ° LOGARITHMS OF TRIGONOMETRIC FUNCTIONS. 535 / L. Sin. - 0 ' 9.83378 1 ' 9.83392 2 1 9.83405 3 1 9.83419 4 1 9.83432 5 9.83446 6 9.83459 7 9.83473 8 9.83486 9 9.83500 10 9.83513 11 9.83527 12 9.83540 13 9.83554 14 9.83567 15 9.83581 16 9.83594 17 9.83608 18 9.83621 19 9.83634 20 9783648 21 9.83661 22 9.83674 23 9.83688 24 9.83701 25 9.83715 26 9.83728 27 9.83741 28 9.83755 29 9.83768 30 9.83781 31 9.83795 32 9.83808 33 9.83821 34 9.83834 35 9.83848 36 9.83861 37 9.83874 38 9.83887 39 9.83901 40 9.83914 41 9.83927 42 9.83940 43 9.83954 44 9.83967 45 9.83980 46 9.83993 47 9.84006 48 9.84020 49 9.84033 50 9.84046 51 9.84059 52 9.84072 53 9.84085 54 9.84098 55 9.84112 56 9.84125 57 9.84138 58 9.84151 59 i 9.84164 60 9.84177 L. Cos. d. L.Tang. 14 13 14 13 14 13 14 13 14 13 14 13 14 13 14 13 14 13 13 14 13 13 14 13 14 13 13 14 13 13 14 13 13 13 14 13 13 13 14 13 13 13 14 13 13 13 13 14 13 13 13 13 13 13 14 13 13 13 13 13 d7 9.97092 .97118 .97143 97168 .97193 96966 96991 97016 97042 .97067 .97219 .97244 97269 .97295 .97320 .97345 .97371 .97396 .97421 .97447 9.97472 9.97497 9.97523 9.97548 9.97573 d.c. I j. cotg. ; L. Cos. d 0.03034 9.86413 25 0.03009 9.86401 J; 25 0.02984 9.86389 j; 26 0.02958 9.86377 25 QC 0.02933 9.86366 ZD 0.02908 9.86354 26 0.02882 9.86342 }: 25 0.02857 9.86330 }: 25 0.02832 9.86318 J; 25 0.02807 9.86306 26 0.02781 9.86295 " 25 0.02756 9.86283 1; 25 0.02731 9.86271 } 26 0.02705 9.86259 } 25 ore 0.02680 9.86247 J Zo 0.02655 9.86235 , 26 0.02629 9.86223 } 25 0.02604 9.86211 } 25 0.02579 9.86200 \ 26 - 25 0.02553 9.86188 | 0.02528 9.86176 . 25 0.02503 9.86164 { 26 0.02477 9.86152 } 25 0.02452 9.86140 } 25 ore 0.02427 9.86128 * 25 26 0.02402 9.86116 1 0.02376 9.86104 ] ; 25 0.02351 9.86092 25 0.02326 9.86080 ; 26 ore 0.02300 9.86068 3 Zu ; 25 0.02275 9.86056 ; 0.02250 9.86044 : ; 26 0.02224 9.86032 : 25 0.02199 9.86020 : 1 t 0.02174 9.86008 : L 25 1 0.02149 9.85996 : 0.02123 9.85984 l 25 0.02098 9.85972 j 25 0.02073 9.85960 5 25 0.02047 9.85948 25 0.02022 9.85936 0.01997 9.85924 0.01971 9.85912 4 25 0.01946 9.85900 9 95 0.01921 9.85888 4 25 o 25 0.01896 9.85876 0.01870 9.85864 5 25 0.01845 9.85851 0 25 0.01820 9.85839 16 25 0.01794 9.85827 i 1 0.01769 9.85815 0.01744 9.85803 d 25 0.01719 9.85791 )7 26 0.01693 9.85779 *2. |5 0.01668 9.85766 >7 25 S3 26 0.01643 . 9.85754 0.01617 9.85742 )8 25 0.01592 ! 9.85730 S3 25 0.01567 r 9.85718 58 26 0.01542 ! 9.85706 84 26 0.01516 I 9.85693 tg. d.c . L.Tang r. L. Sin. 12 12 12 12 12 12 12 12 13 12 12 12 12 12 12 13 12 12 12 12 12 13 d. P. P. 30 59 58 57 6 26 2.6 56 7 3.0 55 8 3.5 54 9 3.9 53 10 4.3 52 20 8.7 51 30 13.0 50 40 17.3 49 50 21.7 48 47 46 25 45 6 2.5 44 7 2.9 43 8 3.3 42 9 3.8 41 10 4.2 40 39 38 37 20 8.3 30 12.5 40 16.7 50 20.8 36 35 14 34 33 6 1.4 32 7 1.6 31 8 1.9 9 2.1 ~3cT 10 2.3 29 20 4.7 28 30 7.0 27 40 9.3 26 50 11.7 25 24 23 22 21 6 7 13 1.3 1.5 20 8 1.7 19 9 2.0 18 10 2.2 17 20 4.3 16 30 i 6.5 15 40 i 8.7 14 50 i 10.8 13 12 11 12 II 10 6 1.2 1.1 9 7 1.4 1.3 8 8 1.6 1.5 7 9 1.8 1.7 6 10 2.0 1.8 5 " 20 4.0 3.7 4 30 6.0 5.5 3 ; 40 8.0 7.3 2 1 1 50 10.0 9.2 0 i t P. P. 46 ° 536 LOGARITHMS OF TRIGONOMETRIC FUNCTIONS. 44 ° / L. Sin. d. L.Tang. d. c. L. Cotg. L. Cos. d. P. P. 0 1 2 3 4 9.84177 9.84190 9.84203 9.84216 9.84229 13 13 13 13 13 13 14 13 13 13 13 13 13 13 13 12 13 13 13 13 13 13 13 13 13 13 13 12 13 13 13 13 13 33 12 13 13 13 13 12 13 13 13 12 13 13 13 12 13 13 13 12 13 13 12 13 13 12 13 13 9.98484 9.98509 9.98534 9.98560 9.98585 25 25 26 25 25 25 26 25 25 26 25 25 25 26 25 25 25 26 25 25 26 25 25 25 26 25 25 25 26 25 25 26 25 25 25 26 25 25 25 26 25 25 25 26 25 25 26 25 25 25 26 25 25 25 26 25 25 25 26 25 0.01516 0.01491 0.01466 0.01440 0.01415 9.85693 9.85681 9.85669 9.85657 9.85645 12 12 12 12 13 12 12 12 13 12 12 12 13 12 12 13 12 12 13 12 12 13 12 12 13 12 13 12 12 13 12 13 12 13 12 12 13 12 13 12 13 12 13 12 13 12 13 12 13 13 12 13 12 13 12 13 13 12 13 12 60 59 58 57 56 26 6 2.6 7 3.0 8 3.5 9 3.9 10 4.3 20 8.7 30 13.0 40 17.3 50 21.7 25 6 2.5 7 2.9 8 3.3 9 3.8 10 4.2 20 8.3 30 12.5 40 16.7 50 20.8 14 6 1.4 7 1.6 8 1.9 9 2.1 10 2.3 20 4.7 30 7.0 40 9.3 50 11.7 13 6 1.3 7 1.5 8 1.7 ! 9 2.0 10 2.2 20 4.3 30 6.5 40 8.7 50 10.8 12 6 1.2 7 1.4 8 1.6 9 1.8 10 2.0 | 20 4.0 30 6.0 40 8.0 50 10.0 5 6 7 8 9 9.84242 9.84255 9.84269 9.84282 9.84295 9.98610 9.98635 9.98661 9.98686 9.98711 0.01390 0.01365 0.01339 0.01314 0.01289 9.85632 9.85620 9.85608 9.85596 9.85583 55 54 53 52 51 10 11 12 13 14 9.84308 9.84321 9.84334 9.84347 9.84360 9.98737 9.98762 9.98787 9.98812 9.98838 0.01263 0.01238 0.01213 0.01188 0.01162 9.85571 9.85559 9.85547 9.85534 9.85522 50 49 48 47 46 15 16 17 18 19 9.84373 9.84385 9.84398 9.84411 9.84424 9.98863 9.98888 9.98913 9.98939 9.98964 0.01137 0.01112 0.01087 0.01061 0.01036 9.85510 9.85497 9.85485 9.85473 9.85460 45 44 43 42 41 20 21 22 23 24 9.84437 9.84450 9.84463 9.84476 9.84489 9.98989 9.99015 9.99040 9.99065 9.99090 0.01011 0.00985 0.00960 0.00935 0.00910 9.85448 9.85436 9.85423 9.85411 9.85399 40 39 38 37 36 25 26 27 28 29 9.84502 9.84515 9.84528 9.84540 9.84553 9.99116 9.99141 9.99166 9.99191 9.99217 0.00884 0.00859 0.00834 0.00809 0.00783 9.85386 9.85374 9.85361 9.85349 9.85337 35 34 33 32 31 30 31 32 33 34 9.84566 9.84579 9.84592 9.84605 9.84618 9.99242 9.99267 9.99293 9.99318 9.99343 0.00758 0.00733 0.00707 0.00682 0.00657 9.85324 9.85312 9.85299 9.85287 9.85274 30 29 28 27 26 35 36 37 38 39 9.84630 9.84643 9.84656 9.84669 9.84682 9.99368 9.99394 9.99419 9.99444 9.99469 0.00632 0.00606 0.00581 0.00556 0.00531 9.85262 9.85250 9.85237 9.85225 9.85212 25 24 23 22 21 40 41 42 43 44 9.84694 9.84707 9.84720 9.84733 9.84745 9.99495 9.99520 9.99545 9.99570 9.99596 0.00505 0.00480 0.00455 0.00430 0.00404 9.85200 9.85187 9.85175 9.85162 9.85150 20 19 18 17 16 45 46 47 48 49 9.84758 9.84771 9.84784 9.84796 9.84809 9.99621 9.99646 9.99672 9.99697 9.99722 0.00379 0.00354 0.00328 0.00303 0.00278 9.85137 9.85125 9.85112 9.85100 9.85087 15 14 13 12 11 50 51 52 53 54 9.84822 9.84835 9.84847 9.84860 9.84873 9.99747 9.99773 9.99798 9.99823 9.99848 0.00253 0.00227 0.00202 0.00177 0.00152 9.85074 9.85062 9.85049 9.85037 9.85024 10 9 8 7 6 55 56 57 58 59 9.84885 9.84898 9.84911 9.84923 9.84936 9.99874 9.99899 9.99924 9.99949 9.99975 0.00126 0.00101 0.00076 0.00051 0.00025 9.85012 9.84999 9.84986 9.84974 9.84961 5 4 3 2 1 60 9.84949 0.00000 0.00000 9.S4949 0 L. Cos. d. L. Cotg. d. c. L.Tang. L. Sin. d. / P. P. 45 ° TEA VERSE TABLES. 537 TRAVERSE TABLES. To use the tables, find the number of degrees In the left-hand column if thfA onp-lp hp Ipss than 45° and in the right-hand column if greater than 45 . The numbers on the same line running across the page are the latitudes and rlpnartures for that angle and for the respective distances, 1, 2, 3, 4, 5, 6, 7, 8, 9, wlSch annear at the top and bottom of the pages. Thus, if the bearing of a Hne be 10° and ^the distance 4, the latitude will be 3.939 and the departure 0 695‘ with the same bearing, and the distance 8, the latitude will be 7.878 and ?i?e < departure^ 1 38? The latitude and departure for 80 is 10 times the latitude and departure for 8, and is found by moving the decimal point one place to the right* that for 500 is 100 times the latitude and departure ior 5, and is found by two places to the right and so on , gy njo^g the decimal point one, two, or more places to the right, the latitude ana dpnarture mav be found for any multiple of any number given m the table. Tn finding - the latitude and departure for any number such as 453, the number is 1 re?olve¥tato^ “number!, viz.: 400, 50 3, and the latitude and departure for each taken from the table and then added together. and departure, neglecting for the first figure of the given distance; write under them the latitude and depar- ture for the second figure , setting them one place farther to the right; un ^J'J ie Jf 1 ) rtlnce the latitude and departure for the third figure , setting them one place still farther to thfrightand so continue until all the figures of tte given distance have been used • add these latitudes and departures , and point off on the right of their sums a number of decimal places equal to the number of the tables being used are carried; the resulting numbers will be the latitude and in feet, links , chains , or whatever unit of measure- xImple^'a bearing is 16° and the distance 725 ft.; what is the latitude and departure? Distances. Latitudes. Departures. 700 6729 1 ®?? 1 20 °147S 5 4806 1378 7~25 6 9 6.9 3 6 1 9 9.7 8 8 Taking the nearest whole numbers and rejecting the decimals, we find the V 7 hirfo a oc d cu^ r \hl given nuU“ next figure must he set fcro P'The^elringfs* £ Tnf^d'isUnle^Tft "required, the latitude and departure. Latitudes. Departures. 900 8345 3371 6490 2622 907 8 4 0.990 339.722 TTptp the nlace of 0 both in the distance column and in the latitude and faffisTiM ^« h 7w^e|a|j goj Van fhe&rr^ and the departure of any bearing, as 30°, is the 1 ol i ts compimne , 60° Where the bearings are given m smaller fractions ot degrees tnan s found in the table, the latitudes and departures can be found by inter- polation. 538 LATITUDES AND DEPARTURES. Bearing. 1 2 3 4 5 Bearing. Lat. Dep. Lat. Dep. Lat. Dep. Lat. Dep. Lat. 0° 1.000 0.000 2.000 0.000 3.000 1 0.000 4.000 0.000 5.000 90° 0* 1.000 0.004 2.000 0.009 3.000 0.013 4.000 0.017 5.000 89f 0* 1.000 0.009 2.000 0.017 3.000 0.026 4.000 0.035 5.000 89* Of 1.000 0.013 2.000 0.026 3.000 0.039 4.000 0.052 5.000 89* 1° 1.000 0.017 2.000 0.035 3.000 0.052 3.999 0.070 4.999 89° l* 1.000 0.022 2.000 0.044 2.999 0.065 3.999 0.087 4.999 88f l* 1.000 0.026 1.999 0.052 2.999 0.079 3.999 0.105 4.998 88* if 1.000 0.031 1.999 0.061 2.999 0.092 3.998 0.122 4.998 88* 2° 0.999 0.035 1.999 0.070 2.998 0.105 3.998 0.140 4.997 88° 2* 0.999 0.039 1.998 0.079 2.998 0.118 3.997 0.157 4.996 87f 2* 0.999 0.044 1.998 0.087 2.997 0.131 3.996 0.174 4.995 87* 2f 0.999 0.048 1.998 0.096 2.997 0.144 3.995 0.192 4.994 87* 3° 0.999 0.052 1.997 0.105 2.996 0.157 3.995 0.209 4.993 87° 3* 0.998 0.057 1.997 0.113 2.995 0.170 3.994 0.227 4.992 86f 3* 0.998 0.061 1.996 0.122 2.994 0.183 3.993 0.244 4.991 86* Bf 0.998 0.065 1.996 0.131 2.994 0.196 3.991 0.262 4.989 86* 4° 0.998 0.070 1.995 0.140 2.993 0.209 3.990 0.279 4.988 86° 4* 0.997 0.074 1.995 0.148 2.992 0.222 3.989 0.296 4.986 85f 4* 0.997 0.078 1.994 0.157 2.991 0.235 3.988 0.314 4.985 85* 4f 0.997 0.083 1.993 0.166 2.990 0.248 3.986 0.331 4.983 85* 5° .0.996 0.087 1.992 0.174 2.989 0.261 3.985 0.349 4.981 85° 5* 0.996 0.092 1.992 0.183 2.987 0.275 3.983 0.366 4.979 84f 5* 0.995 0.096 1.991 0.192 2.986 0.288 3.982 0.383 4.977 84* 5f 0.995 0.100 1.990 0.200 2.985 0.301 3.980 0.401 4.975 84* 6° 0.995 0.105 1.989 0.209 2.984 0.314 3.978 0.418 4.973 84 a 6* 0.994 0.109 1.988 0.218 2.982 0.327 3.976 0.435 4.970 83f 6* 0.994 0.113 1.987 0.226 2.981 0.340 3.974 0.453 4.968 83* 6f 0.993 0.118 1.986 0.235 2.979 0.353 3.972 0.470 4.965 83* 7° 0.993 0.122 1.985 0.244 2.978 0.366 3.970 0.487 4.963 83° 7* 0.992 0.126 1.984 0.252 2.976 0.379 3.968 0.505 4.960 82f n 0.991 0.131 1.983 0.261 2.974 0.392 3.966 0.522 4.957 82* 7f 0.991 0.135 1.982 0.270 2.973 0.405 3.963 0.539 4.954 82* 8° 0.990 0.139 1.981 0.278 2.971 0.418 3.961 0.557 4,951 82° 8* 0.990 0.143 1.979 0.287 2.969 0.430 3.959 0.574 4.948 81f 8* 0.989 0.148 1.978 0.296 2.967 0.443 3.956 0.591 4.945 81* 8f 0.988 0.152 1.977 0.304 2.965 0.456 3.953 0.608 4.942 81* 9° 0.988 0.156 1.975 0.313 2.963 0.469 3.951 0.626 4.938 81° 9* 0.987 0.161 1.974 0.321 2.961 0.482 3.948 0.643 4.935 80f 9* 0.986 0.165 1.973 0.330 2.959 0.495 3.945 0.660 4.931 80* 9f 0.986 0.169 1.971 0.339 2.957 0.508 3.942 0.677 4.928 80* 10° 0.985 0.174 1.970 0.347 2.954 0.521 3.939 0.695 4.924 80° io* 0.984 0.178 1.968 0.356 2.952 0.534 3.936 0.712 4.920 79f 10| 0.983 0.182 1.967 0.364 2.950 0.547 3.933 0.729 4.916 79* lOf 0.982 0.187 1.965 0.373 2.947 0.560 3.930 0.746 4.912 79* ,,o 0.982 0.191 1.963 0.382 2.945 0.572 3.927 0.763 4.908 79° 1 H 0.981 0.195 1.962 0.390 2.942 0.585 3.923 0.780 4.904 78f Hi 0.980 0.199 1.960 0.399 2.940 0.598 3.920 0.797 4.900 78* -lif 0.979 0.204 1.958 0.407 2.937 0.611 3.916 0.815 4.895 78* 12° 0.978 0.208 1.956 0.416 2.934 0.624 3.913 0.832 4.891 78° 12* 0.977 0.212 1.954 0.424 2.932 0.637 3.909 0.849 4.886 77f 12* 0.976 0.216 1.953 0.433 2.929 0.649 3.905 0.866 4.881 77* 12f 0.975 0.221 1.951 0.441 2.926 0.662 3.901 0.883 4.877 77* 13° 0.974 0.225 1.949 0.450 2.923 0.675 3.897 0.900 4.872 77° bub c Dep. Lat. Dep. Lat. Dep. Lat. Dep. Lat. Dep. bi c *lZ co 69 as 1 2 3 4 5 CO CD LATITUDES AND DEPARTURES. 539 feb c 5 6 7 8 9 th C 'u 1— 40 a> CD Dep. Lat. Dep. Lat. Dep. Lat. Dep. Lat. Dep. CO 0° 0.000 6.000 0.000 7.000 0.000 8.000 0.000 9.000 0.000 90° 0- 0 022 6.000 0.026 7.000 0.031 8.000 0.035 9.000 0.039 89$ 0 1 0 044 6.000 0.052 7.000 0.061 8.000 0.070 9.000 0.079 89$ f n 0 065 5.999 0.079 6.999 0.092 7.999 0.105 8.999 0.118 89$ 1° 0 087 5.999 0.105 6.999 0.122 7.999 0.140 8.999 0.157 89° 1 1 0 109 5.999 0.131 6.998 0.153 7.998 0.175 8.998 0.196 88$ 1 1 0 131 5.998 0.157 6.998 0.183 7.997 0.209 8.997 0.236 88$ 13 0 153 5.997 0.183 6.997 0.214 7.996 0.244 8.996 0.275 88$ 2° 0 174 5.996 0.209 6.996 0.244 7.995 0.279 8.995 0.314 88° 2i 0 196 5.995 0.236 6.995 0.275 7.994 0.314 8.993 0.353 87$ Oi 0 218 5.994 0.262 6.993 0.305 7.992 0.349 8.991 0.393 87i 91 0 240 5.993 0.288 6.992 0.336 7.991 0.384 8.990 0.432 87$ 3° 0 262 5.992 0.314 6.990 0.366 7.989 0.419 8.988 0.471 8 7° 3 1 0 283 5.990 0.340 6.989 0.397 7.987 0.454 8.986 0.510 86$ 31 0 305 5.989 0.366 6.987 0.427 7.985 0.488 8.983 0.549 86i 0 327 5.987 0.392 6.985 0.458 7.983 0.523 ■ 8.981 0.589 86$ 4° 0 349 5.985 0.419 6.983 0.488 7.981 0.558 8.978 0.628 86° 4 1 0 371 5.984 0.445 6.981 0.519 7.978 0.593 8.975 0.667 85$ 4 1 0 392 5.982 0.471 6.978 0.549 7.975 0.628 8.972 0.706 85$ 41 0.414 5.979 0.497 6.976 0.580 7.973 0.662 8.969 0.745 85$ 5° 0.436 5.977 0.523 6.973 0.610 7.970 0.697 8.966 0.784 85° 5 1 0.458 5.975 0.549 6.971 0.641 7.966 0.732 8.962 0.824 84$ 51 0.479 5.972 0.575 6.968 0.671 7.963 0.767 8.959 0.863 84$ 0.501 5.970 0.601 6.965 0.701 7.960 0.802 8.955 0.902 84$ 6° 0.523 5.967 0.627 6.962 0.732 7.956 0.836 8.951 0.941 84° 6i 0.544 5.964 0.653 6.958 0.762 7.952 0.871 8.947 0.980 83$ 0.566 5.961 0.679 6.955 0.792 7.949 0.906 8.942 1.019 83$ u 9 A3. 0.588 5.958 0.705 6.951 0.823 7.945 0.940 8.938 1.058 83$ V»4 7° 0.609 5.955 0.731 6.948 0.853 7.940 0.975 8.933 1.097 83° 7± 0.631 5.952 0.757 6.944 0.883 7.936 1.010 8.928 1.136 82$ 7 i 0.653 5.949 0.783 6.940 0.914 7.932 1.044 8.923 1.175 82$ 73- 0.674 5.945 0.809 6.936 0.944 7.927 1.079 8.918 1.214 82$ 8° 0.696 5.942 0.835 6.932 0.974 7.922 1.113 8.912 1.253 82° 84 0.717 5.938 0.861 6.928 1.004 7.917 1.148 8.907 1.291 81$ °4 8$ 0.739 5.934 0.887 6.923 1.035 7.912 1.182 8.901 1.330 81$ °a 8$ 0.761 5.930 0.913 6.919 1.065 7.907 1.217 8.895 1.369 81$ °4 9° 0.782 5.926 0.939 6.914 1.095 7.902 1.251 8.889 1.408 8 1^ 9$ 0.804 5.922 0.964 6.909 1.125 7.896 1.286 8.883 1.447 80$ gi- 0.825 5.918 0.990 6.904 1.155 7.890 1.320 8.877 1.485 80$ “Q 9$ 0.847 5.913 1.016 6.899 1.185 7.884 1.355 8.870 1.524 • — - — ■ 80$ 10° 0.868 5.909 1.042 6.894 1.216 7.878 1.389 8.863 1.563 80° 10$ 0.890 5.904 1.068 6.888 1.246 7.872 1.424 8.856 1.601 79$ 10^ 0.911 5.900 1.093 6.883 1.276 7.866 1.458 8.849 1.640 79$ 10$ 0.933 5.895 1.119 6.877 1.306 7.860 1.492 8.842 1.679 79$ 1 1° 0.954 5 890 1.145 6.871 1.336 7.853 1.526 8.835 1.717 79° 111 0.975 5.885 1.171 6.866 1.366 7.846 1.561 8.827 1.756 78$ Hi 0.997 5.880 1.196 6.859 1.396 7.839 1.595 8.819 1.794 78$ 111 1.018 5.874 1.222 6.853 1.425 7.832 1.629 8.811 1.833 12° 1.040 5.869 1.247 6.847 1.455 7.825 1.663 8.803 1.871 78° 12$ 1.061 5.863 1.273 6.841 1.485 7.818 1.697 8.795 1.910 77$ 12i 1.082 5.858 1.299 6.834 1.515 7.810 1.732 8.787 1.948 77$ 12$ 1.103 5.852 1.324 6.827 1.545 7.803 1.766 8.778 1.986 77$ mm — ft 13° 1.125 5.846 1.350 6.821 1.575 7.795 1.800 8.769 2.025 77° bh c Lat. Dep. Lat. Dep. Lat. Dep. Lat. Dep. 1 Lat. bb c _ k_ 40 42 CD 5 6 7 8 9 a> CD 540 LATITUDES AND DEPARTURES. tio «= 1 2 3 4 5 bi «D JD CO Lat. Dep. Lat. Dep. Lat. Dep. Lat. Dep. Lat. to 0> CO 13° 0.974 0.225 1.949 0.450 2.923 0.675 3.897 0.900 4.872 77° 131 0.973 0.229 1.947 0.458 2.920 0.688 3.894 0.917 4.867 76$ 13i 0.972 0.233 1.945 0.467 2.917 0.700 3.889 0.934 4.862 761 13$ 0.971 0.238 1.943 0.475 2.914 0.713 3.885 0.951 4.857 761 14° 0.970 0.242 1.941 0.484 2.911 0.726 3.881 0.968 4.851 76° 141 0.969 0.246 1.938 0.492 2.908 0.738 3.877 0.985 4.846 75$ 14i 0.968 0.250 1.936 0.501 2.904 0.751 3.873 1.002 4.841 751 14$ 0.967 0.255 1.934 0.509 2.901 0.764 3.868 1.018 4.835 751 15° 0.966 0.259 1.932 0.518 2.898 0.776 3.864 1.035 4.830 75° 151 0.965 0.263 1.930 0.526 2.894 0.789 3.859 1.052 4.824 74$ 151 0.964 0.267 1.927 0.534 2.891 0.802 3.855 1.069 4.818 741 15$ 0.962 0.271 1.925 0.543 2.887 0.814 3.850 ' 1.086 4.812 741 16° 0.961 0.276 1.923 0.551 2.884 0.827 3.845 1.103 4.806 74° 161 0.960 0.280 1.920 0.560 2.880 0.839 3.840 1.119 4.800 'CO Mu 161 0.959 0.284 1.918 0.568 2.876 0.852 3.835 1.136 4.794 731 16$ 0.958 0.288 1.915 0.576 2.873 0.865 3.830 1.153 4.788 731 17° 0.956 0.292 1.913 0.585 2.869 0.877 3.825 1.169 4.782 73° m 0.955 0.297 1.910 0.593 2.865 0.890 3.820 1.186 4.775 72$ 171 0.954 0.301 1.907 0.601 2.861 0.902 3.815 1.203 4.769 721 17$ 0.952 0.305 1.905 0.610 2.857 0.915 3.810 1.220 4.762 721 18° 0.951 0.309 1.902 0.618 2.853 0.927 3.804 1.236 4.755 72° 181 0.950 0.313 1.899 0.626 2.849 0.939 3.799 1.253 4.748 71$ 181 0.948 0.317 1.897 0.635 2.845 0.952 3.793 1.269 4.742 711 18| 0.947 0.321 1.894 0.643 2.841 0.964 3.788 1.286 4.735 711 19° 0.946 0.326 1.891 0.651 2.837 0.977 3.782 1.302 4.728 71° 191 0.944 0.330 1.888 0.659 2.832 0.989 3.776 1.319 4.720 70$ m 0.943 0.334 1.885 0.668 2.828 1.001 3.771 1.335 4.713 701 19$ 0.941 0.338 1.882 0.676 2.824 1.014 3.765 1.352 4.706 701 20° 0.940 0.342 1.879 0.684 2.819 1.026 3.759 1.368 4.698 70° 201 0.938 0.346 1.876 0.692 2.815 1.038 3.753 1.384 4.691 69$ 20i 0.937 0.350 1.873 0.700 2.810 1.051 3.747 1.401 4.683 691 20f 0.935 0.354 1.870 0.709 2.805 1.063 3.741 1.417 4.676 691 21° 0.934 0.358 1.867 0.717 2.801 1.075 3.734 1.433 4.668 69° 2H 0.932 0.362 1.864 0.725 2.796 1.087 3.728 1.450 4.660 68$ 211 0.930 0.367 1.861 0.733 2.791 1.100 3.722 1.466 4.652 681 21$ 0.929 0.371 1.858 0.741 2.786 1.112 3.715 1.482 4.644 681 22° 0.927 0.375 1.854 0.749 2.782 1.124 3.709 1.498 4.636 68° 22i 0.926 0.379 1.851 0.757 2.777 1.136 3.702 1.515 4.628 67$ 22i 0.924 0.383 1.848 0.765 2.772 1.148 3.696 1.531 4.619 671 22$ 0.922 0.387 1.844 0.773 2.767 1.160 3.689 1.547 4.611 671 23° 0.921 0.391 1.841 0.781 2.762 1.172 3.682 1.563 4.603 67° 23i 0.919 0.395 1.838 0.789 2.756 1.184 3.675 1.579 4.594 66$ 23i 0.917 0.399 1.834 0.797 2.751 1.196 3.668 1.595 4.585 661 23$ 0.915 0.403 1.831 0.805 2.746 1.208 3.661 1.611 4.577 661 24° 0.914 0.407 1.827 0.813 2.741 1.220 3.654 1.627 4.568 66° 24i 0.912 0.411 1.824 0.821 2.735 1.232 3.647 1.643 4.559 65$ 24i 0.910 0.415 1.820 0.829 2.730 1.244 3.640 1.659 4.550 651 24$ 0.908 0.419 1.816 0.837 2.724 1.256 3.633 1.675 4.541 651 25° 0.906 0.423 1.813 0.845 2.719 1.268 3.625 1.690 4.532 65° 25i 0.904 0.427 1.809 0.853 2.713 1.280 3.618 1.706 4.522 64$ 25i 0.903 0.431 1.805 0.861 2.708 1.292 3.610 1.722 4.513 641 25$ 0.901 0.434 1.801 0.869 2.702 1.303 3.603 1.738 4.503 641 26° 0.899 0.438 1.798 0.877 2.696 1.315 3.595 1.753 4.494 64° bfi c &_ Dep. Lat. Dep. Lat. Dep. Lat. Dep. Lat. Dep. bi c u CO «> CO ' 2 3 4 5 <0 c Lat. Dep. Lat. Dep. Lat. Dep. Lat. Dep. Lat. fci c u k— <0 03 CO 5 6 7 . 8 9 CO 0> 00 542 LATITUDES AND DEPARTURES. Bearing. . 2 3 4 5 Bearing. Lat. Dep. Lat. Dep. Lat. Dep. Lat. Dep. Lat. 26° 0.899 0.438 1.798 0.877 2.696 1.315 3.595 1.753 4.494 64° 26* 0.897 0,442 1.794 0.885 2.691 1.327 3.587 1.769 4.484 63* 26* 0.895 0.446 1.790 0.892 2.685 1.339 3.580 1.785 4.475 63* 26* 0.893 0.450 1.786 0.900 2.679 1.350 3.572 1.800 4.465 63* 27° 0.891 0.454 1.782 0.908 2.673 1.362 3.564 1.816 4.455 63° 27* 0.889 0.458 1.778 0.916 2.667 1.374 3.556 1.831 4.445 62* 27* 0.887 0.462 1.774 0.923 2.661 1.385 3.548 1.847 4.435 62* 27* 0.885 0.466 1.770 0.931 2.655 1.397 3.540 1.862 4.425 62* 28° 0.883 0.469 1.766 0.939 2.649 1.408 3.532 1.878 4.415 62° 28* 0.881 0.473 1.762 0.947 2.643 1.420 3.524 1.893 4.404 61* 28 g- 0.879 0.477 1.758 0.954 2.636 1.431 3.515 1.909 4.394 61* 28* 0,877 0.481 1.753 0.962 2.630 1.443 3.507 1.924 4.384 61* 29° 0.875 0.485 1.749 0.970 2.624 1.454 3.498 1.939 4.373 61° 29* 0.872 0.489 1.745 0.977 2.617 1.466 3.490 1.954 4.362 60* 29* 0.870 0.492 1.741 0.985 2.611 1.477 3.481 1.970 4.352 60* 29* 0.868 0.496 1.736 0.992 2.605 1.489 3.473 1.985 4.341 60* 30° 0.866 0.500 1.732 1.000 2.598 1.500 3.464 2.000 4.330 60° 30* 0.864 0.504 1.728 1.008 2.592 1.511 3.455 2.015 4.319 59* 30* 0.862 0.508 1.723 1.015 2.585 1.523 3.447 2.030 4.308 59* 30* 0.859 0.511 1.719 1.023 2.578 1.534 3.438 2.045 4.297 59* 31° 6.857 0.515 1.714 1.030 2.572 1.545 3.429 2.060 4.286 59° 31* 0.855 0.519 1.710 1.038 2.565 1.556 3.420 2.075 4.275 58* 31* 0.853 0.522 1.705 1.045 2.558 1.567 3.411 2.090 4.263 58* 31* 0.850 0.526 1.701 1.052 2.551 1.579 3.401 2.105 4.252 58* 32° 0.848 0.530 1.696 1.060 2.544 1.590 3.392 2.120 4.240 58° 32* 0.846 0.534 1.691 1.067 2.537 1.601 3.383 2.134 4.229 57* 32* 0.843 0.537 1.687 1.075 2.530 1.612 3.374 2.149 4.217 57* 32* 0.841 0.541 1.682 1.082 2.523 1.623 3.364 2.164 4.205 57* 33° 0.839 0.545 1.677 1.089 2.516 1.634 3.355 2.179 4.193 57° 33* 0.836 0.548 1.673 1.097 2.509 1.645 3.345 2.193 4.181 56* 33* 0.834 0.552 1.668 1.104 2.502 1.656 3.336 2.208 4.169 56* 33* 0.831 0.556 1.663 1.111 2.494 1.667 3.326 2.222 4.157 56* 34° 0.829 0.559 1.658 1.118 2.487 1.678 3.316 2.237 4.145 56° 34* 0.827 0.563 1.653 1.126 2.480 1.688 3.306 2.251 4.133 55* 34* 0.824 0.566 1.648 1.133 2.472 1.699 3.297 2.266 4.121 55* 34* 0.822 0.570 1.643 1.140 2.465 1.710 3.287 2.280 4.108 55* 35° 0.819 0.574 1.638 1.147 2.457 1.721 3.277 2.294 4.096 55° 35* 0.817 0.577 1.633 1.154 2.450 1.731 3.267 2.309 4.083 54* 35* 0.814 0.581 1.628 1.161 2.442 1.742 3.257 2.323 4.071 54* 35* 0.812 0.584 1.623 1.168 2.435 1.753 3.246 2.337 4.058 54* 36° 0.809 0.588 1.618 1.176 2,427 1.763 3.236 2.351 4.045 54° 36* 0.806 0.591 1.613 1.183 2.419 1.774 3.226 2.365 4.032 53* 36* 0.804 0.595 1.608 1.190 2.412 1.784 3.215 2.379 4.019 53* 36* 0.801 0.598 1.603 1.197 2.404 1.795 3.205 2.393 4.006 53* 37° 0.799 0.602 1.597 1.204 2.396 1.805 3.195 2.407 3.993 53° 37* 0.796 0.605 1.592 1.211 2,388 1.816 3.184 2.421 3.980 52* 37* 0.793 0.609 1.587 1.218 2.380 1.826 3.173 2.435 3.967 52* 37* 0.791 0.612 1.581 1.224 2.372 1.837 3.163 2.449 3.953 52* 38° 0.788 0.616 1.576 1.231 2.364 1.847 3.152 2.463 3.940 52° 38* 0.785 0.619 1.571 1.238 2.356 1.857 3.141 2.476 3.927 51* 38* 0.783 0.623 1.565 1.245 2.348 1.868 3.130 2.490 3.913 51* 38* 0.780 0.626 1.560 1.252 2.340 1.878 3.120 2.504 3.899 51* 39° 0.777 0.629 1.554 1.259 2.331 1.888 3.109 2.517 3.886 51° eh c i_ Dep. Ld;t« Dep. Lat. Dep. Lat. Dep. Lat. Dep. tab c CO CO Lat. Dep. Lat. Dep. Lat. Dep. Lat. Dep. 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Dep. Lat. Dep. Lat. Dep. Lat. Dep. Lat. Dep. Bear- ing. do C Z 5 6 7 8 9 bi c u CO 03 00 Dep. Lat. Dep. Lat. Dep. Lat. Dep. Lat. Dep. CD SO 39° 3.147 4.663 3.776 5.440 4.405 6.217 5.035 6.994 5.664 “Ti 5 " 39£ 3.164 4.646 3.796 5.421 4.429 6.195 5.062 6.970 5.694 50£ 39k 3.180 4.630 3.816 5.401 4.453 6.173 5.089 6.945 5.725 50| 39} 3.197 4.613 3.837 5.382 4.476 6.151 5.116 6.920 5.755 50£ 40° 3.214 4.596 3.857 5.362 4.500 6.128 5.142 6.894 5,785 50° 40£ 3.231 4.579 3.877 5.343 4.523 6.106 5.169 6.869 5.’815 49} 40| 3.247 4.562 3.897 5.323 4.546 6.083 5.196 6.844 5.845 49k 40£ 3.264 4.545 3.917 5.303 4.569 6.061 5.222 6.818 5.875 49£ 41° 3.280' 4.528 3.936 5.283 4.592 6.038 5.248 6.792 5.905 49° 41£ 3.297 4.511 3.956 5.263 4.615 6.015 5.275 6.767 5.934 43} 41! 3.313 4.494 3.976 5.243 4.638 5.992 5.301 6.741 5.964 43k 41£ 3.329 4.476 3.995 5.222 4.661 5.968 5.327 6.715 5.993 48£ 42° 3.346 4.459 4.015 5.202 4.684 5.945 5.353 6.688 6.022 48° 42£ 3.362 4.441 4.034 5.182 4.707 • 5.922 5.379 6.662 6.051 47} 42! 3.378 4.424 4.054 5.161 4.729 5.898 5.405 6.635 6.080 47 k 42f 3.394 4.406 4.073 5.140 4.752 5.875 5.430 6.609 6.109 47£ 43° 3.410 4.388 4.092 5.119 4.774 5.851 5.456 6.582 6.138 47° 43£ 3.426 4.370 4.111 5.099 4.796 5.827 5.481 6.555 6.167 46} 43! 3.442 4.352 4.130 5.078 4.818 5.803 5.507 6.528 6.195 46! 43£ 3.458 4.334 4.149 5.057 4.841 5.779 5.532 6.501 6.224 46£ 44° 3.473 4.316 4.168 5.035 4.863 5.755 5.557 6.474 6.252 46° 44£ 3.489 4.298 4.187 5.014 4.885 5.730 5.582 6.447 6.280 45} 44! 3.505 4.280 4.206 4.993 4.906 5.706 5.607 6.419 6.308 45! 44£ 3.520 4.261 4.224 4.971 4.928 5.681 5.632 6.392 6.336 45£ 45° 3.536 4.243 4.243 4.950 4.950 5.657 5.657 6.364 6.364 45° Bear- ing. Lat. Dep. Lat. Dep. Lat. Dep. Lat. Dep. Lat. Bear- ing. CIRCUMFERENCES, AND AREAS. 545 SQUARES, CUBES, SQUARE AND CUBE ROOTS, CIRCUMFERENCES, AND AREAS. No. Square. Cube. 3q. Root. 1 Cu. Root. Reciprocal. Circum. Area. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 1 4 9 16 25 36 49 64 81 100 121 144 169 196 225 256 289 324 361 400 441 484 529 576 625 676 729 784 841 900 961 1.024 1,089 1,156 1,225 1,296 1,369 1,444 1,521 1,600 1,681 1,764 1,849 1,936 2.025 2,116 2,209 2,304 2,401 2,500 2,601 2,704 2,809 2,916 3.025 1 8 27 64 125 216 343 512 729 1,000 1,331 1,728 2,197 2,744 3.375 4,096 4,913 5,832 6,859 8,000 9,261 10,648 12,167 13,824 15,625 17,576 19,683 21,952 24,389 27.000 29,791 32,768 35,937 39,304 42,875 46,656 50,653 54.872 59,319 64.000 68,921 74,088 79,507 85,184 91,125 97,336 103,823 110,592 117,649 125.000 132,651 140,608 148,877 157,464 166.375 1.0000 1.4142 1.7321 2.0000 2.2361 2.4495 2.6458 2.8284 3.0000 3.1623 3.3166 3.4641 3.6056 3.7417 3.8730 4.0000 4.1231 4.2426 4.3589 4.4721 4.5826 4.6904 4.7958 4.8990 5.0000 5.0990 5.1962 5.2915 5.3852 5.4772 5.5678 5.6569 5.7446 5.8310 5.9161 6.0000 6.0828 6.1644 6.2450 6.3246 6.4031 6.4807 6.5574 6.6332 6.7082 6.7823 6.8557 6.9282 7.0000 7.0711 7.1414 7.2111 7.2801 7.3485 7.4162 1.0000 ] 1.2599 1.4422 1.5874 1.7100 1.8171 1.9129 2.0000 2.0801 2.1544 2.2240 2.2894 2.3513 2.4101 2.4662 2.5198 2.5713 2.6207 2.6684 2.7144 2.7589 2.8020 ' 2.8439 2.8845 2.9240 2.9625 3.0000 3.0366 3.0723 3.1072 3.1414 3.1748 3.2075 3.2396 3.2717 3.3019 3.3322 3.3620 3.3912 3.4200 3.4482 3.4760 3.5034 3.5303 3.5569 3.5830 3.6088 3.6342 3.6593 3.6840 3.7084 3.7325 3.7563 3.7798 3.8030 L.000000000 .500000000 .333333333 .250000000 .200000000 .166666667 .142857143 .125000000 .111111111 .100000000 .090909091 .083333333 .076923077 .071428571 .066666667 .062500000 .058823529 .055555556 .052631579 .050000000 .047619048 .045454545 .043478261 .041666667 .040000000 .038461538 .037037037 .035714286 .034482759 .033333333 .032258065 .031250000 .030303030 .029411765 .028571429 .027777778 .027027027 .026315789 .025641026 .025000000 .024390244 .023809524 .023255814 .022727273 .022222222 .021739130 .021276600 .020833333 .020408163 .020000000 .019607843 .019230769 .018867925 .018518519 .018181818 3.1416 6.2832 9.4248 12.5664 15.7080 18.850 21.991 25.133 28.274 31.416 34.558 37-699 40.841 43.982 47.124 50.265 53.407 56.549 59.690 62.832 65.973 69.115 72.257 75.398 78.540 81.681 84.823 87.965 91.106 94.248 97.389 100.53 103.67 106.81 109.96 113.10 116.24 119.38 122.52 125.66 128.81 131.95 135.09 138.23 141.37 144.51 147.65 150.80 153.94 157.08 160.22 163.36 166.50 169.65 172.79 0.7854 3.1416 7.0686 12.5664 19.635 28.274 38.485 50.266 63.617 78.540 95.033 113.10 132.73 153.94 176.71 201.06 226.98 254.47 283.53 314.16 346.36 380.13 415.48 452.39 490.87 530.93 572.56 615.75 660.52 706.86 754.77 804.25 855.30 907.92 962.11 1,017.88 1.075.21 1,134.11 1,194.59 1,256.64 1,320.25 1,385.44 1,452.20 1.520.53 1,590.43 1,661.90 1.734.94 1,809.56 1,885.74 1,963.50 1 2.042.82 2,123.72 2,206.18 2.290.22 ! 2.375.83 546 SQUARES, CUBES, SQUARE AND CUBE ROOTS , No. Square. Cube. Sq. Root. Cu. Root. Reciprocal. Circum. Area. 56 3,136 175,616 7.4833 3.8259 .017857143 175.93 2,463.01 57 3,249 185,193 7.5498 3.8485 .017543860 179.07 2,551.76 58 3,364 195,112 7.6158 3.8709 .017241379 182.21 2,642.08 59 3,481 205,379 7.6811 3.8930 .016949153 185.35 2,733.97 60 3,600 216,000 7.7460 3.9149 .016666667 188.50 2,827.43 61 3,721 226,981 7.8102 3.9365 .016393443 191.64 2,922.47 62 3,844 238,328 7.8740 3.9579 .016129032 194.78 3,019.07 63 3,969 250,047 7.9373 3.9791 .015873016 197.92 3,117.25 64 4,096 262,144 8.0000 4.0000 .015625000 201.06 3,216.99 65 4,225 274,625 8.0623 4.0207 .015384615 204.20 3,318.31 66 4,356 287,496 8.1240 4.0412 .015151515 207.34 3,421.19 67 4,489 300,763 8.1854 4.0615 .014925373 210.49 3,525.65 68 4,624 314,432 8.2462 4.0817 .014705882 213.63 3,631.68 69 4^761 328,509 8.3066 4.1016 .014492754 216.77 3,739.28 70 4,900 343,000 8.3666 4.1213 .014285714 219.91 3,848.45 71 5,041 357,911 8.4261 4.1408 .014084517 223.05 3,959.19 72 5,184 373,248 8.4853 4.1602 .013888889 226.19 4,071.50 73 5,329 389,017 8.5440 4.1793 .013698630 229.34 4,185.39 74 5,476 405,224 8.6023 4.1983 .013513514 232.48 4,300.84 75 5,625 421,875 8.6603 4.2172 .013333333 235.62 4,417.86 76 5,776 438,976 8.7178 4.2358 .013157895 238.76 4,536.46 77 5*929 456,533 8.7750 4.2543 .012987013 241.90 4,656.63 78 6,084 474,552 8.8318 4.2727 .012820513 245.04 4,778.36 79 6,241 493,039 8.8882 4.2908 .012658228 248.19 4,901.67 80 6,400 512,000 8.9443 4.3089 .012500000 251.33 5,026.55 81 6,561 531,441 9.0000 4.3267 .012345679 254.47 5,153.00 82 6,724 551,368 9.0554 4.3445 .012195122 257.61 5,281.02 83 6 i 889 571,787 9.1104 4.3621 .012048193 260.75 5,410.61 84 7,056 592,704 9.1652 4.3795 .011904762 263.89 5,541.77 85 7,225 614,125 9.2195 4.3968 .011764706 267.04 5,674.50 86 7,396 636,056 9.2736 4.4140 .011627907 270.18 5,808.80 87 7,569 658,503 9.3274 4.4310 .011494253 273.32 5,944.68 88 7,744 681,472 9.3808 4.4480 .011363636 276.46 6,082.12 89 7.921 704,969 9.4340 4.4647 .011235955 279.60 6,221.14 90 8,100 729,000 9.4868 4.4814 .011111111 282.74 6,361.73 91 8,281 753,571 9.5394 4.4979 .010989011 285.88 6,503.88 92 8,464 778,688 9.5917 4.5144 .010869565 289.03 6,647.61 93 8,649 804,357 9.6437 4.5307 .010752688 292.17 6,792.91 94 8,836 830,584 9.6954 4.5468 .010638298 295.31 6,939.78 95 9,025 857,375 9; 7468 4.5629 .010526316 298.45 7,088.22 96 9,216 884,736 9.7980 4.5789 .410416667 301.59 7,238.23 97 9,409 912,673 9.8489 4.5947 .010309278 304.73 7,389.81 98 9,604 941,192 9.8995 4.6104 .010204082 307.88 7,542.96 99 9,801 970,299 9.9499 4.6261 .010101010 311.02 7,697.69 100 10,000 1,000,000 10.0000 4.6416 .010000000 314.16 7,853.98 101 10,201 1,030,301 10.0499 4.6570 .009900990 317.30 8,011.85 102 10,404 1,061,208 10.0995 4.6723 .009803922 320.44 8,171.28 103 10,609 1,092,727 10.1489 4.6875 .009708738 323.58 8,332.29 104 10,816 1,124,864 10.1980 4.7027 .009615385 326.73 8,494.87 105 11,025 1,157,625 10.2470 4.7177 .009523810 329.87 8,659.01 106 11,236 1,191,016 10.2956 4.7326 .009433962 333.01 8,824.73 107 11,449 1,225,043 10.3441 4.7475 .009345794 336.15 8.992.02 108 11,664 1,259,712 10.3923 4.7622 .009259259 339.29 9,160.88 109 11,881 1,295,029 10.4403 4.7769 .009174312 342.43 9,331.32 110 12,100 1,331,000 10.4881 4.7914 .009090909 345.58 9,503.32 111 12,321 1,367,631 10.5357 4.8059 .009009009 348.72 9,676.89 112 12,544 1,404,928 10.5830 4.8203 .008928571 351.86 9,852.03 113 12,769 1,442,897 10.6301 4.8346 .008849558 355.00 10,028.75 114 12,996 1,481,544 10.6771 4.8488 .008771930 358.14 10,207.03 115 13,225 1,520,875 10.7238 4.8629 .008695652 361.28 10,386.89 116 13,456 1,560,896 10.7703 4.8770 .008020690 364.42 10,568.32 117 13,689 1,601,613 10.8167 4.8910 .008547009 367.57 10,751.32 118 13,924 1,643,032 10.8628 4.9049 .008474576 370.71 10,935.88 CIRCUMFERENCES, AND AREAS. 547 I 1 No. Square. Cube. Sq. Root. Cu. Root. Reciprocal. Circum. Area. 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 14.161 14,400 14.641 14,834 15.129 15,376 15,625 15,876 16.129 16,384 16.641 16,900 17.161 17,424 17,689 17,956 18,225 18,496 18,769 19,044 19,321 19.600 19,881 20,164 20,449 20,736 21.025 21,316 21,609 21,904 22,201 22,500 22,801 23,104 23,409 23,716 24.025 24,336 24,649 24,964 25,281 25.600 25,921 26,244 26,569 26,896 27,225 27,556 27,889 28,224 28,561 28,900 29,241 28,584 29,929 30,276 30,625 30,976 31,329 31,684 32,041 32,400 32,761 1,685,159 1.728.000 1,771,561 1,815,848 1,860,867 1.906.624 1,953,125 2,000,376 2,048,383 2,097,152 2,146,689 2.197.000 2,248,091 2,299,968 2,352,637 2,406,104 2,460,375 2,515,456 2,571,353 2,628,072 2,685,619 2.744.000 2,803,221 2,863,288 2,924,207 2,985,984 3.048.625 3,112,136 3,176,523 3,241,792 3,307,949 3.375.000 3,442,951 3,511,008 3,581,577 3,652,264 3,723,875 3,796,416 3,869,893 3,944,312 4,019,679 4.096.000 4,173,281 4,251,528 4,330,747 4,410,944 4,492,125 4,574,296 4,657,463 4,741,632 4,826,809 4.913.000 5,000,211 5,088,448 5,177,717 5,268,024 5,359,375 5,451,776 5,545,233 5,639,752 5,735,339 5.832.000 5,929,741 10.9087 10.9545 11.0000 11.0454 11.0905 11.1355 11.1803 11.2250 11.2694 11.3137 11.3578 11.4018 11.4455 11.4891 11.5326 11.5758 11.6190 11.6619 11.7047 11.7473 11.7898 11.8322 11.8743 11.9164 11.9583 12.0000 12.0416 12.0830 12.1244 12.1655 12.2066 12.2474 12.2882 12.3288 12.3693 12.4097 12.4499 12.4900 12.5300 12.5698 12.6095 12.6491 12.6886 12.7279 12.7671 12.8062 12.8452 12.8841 12.9228 12.9615 13.0000 13.9384 13.0767 13.1149 13.1529 13.1909 13.2288 13.2665 13.3041 13.3417 13.37 &L 13.4164 13.4536 4.9187 4.9324 4.9461 4.9597 4.9732 4.9866 5.0000 5.0133 5.0265 5.0397 5.0528 5.0658 5.0788 5.0916 5.1045 5.1172 5.1299 5.1426 5.1551 51676 5.1801 5.1925 5.2048 5.2171 5.2293 5.2415 5.2536 5.2656 5.2776 5.2896 5.3015 5.3133 5.3251 5.3368 5.3485 5.3601 5.3717 5.3832 5.3947 5.4061 5.4175 5.4288 5.4401 5.4514 5.4626 5.4737 5.4848 5.4959 5.5069 5.5178 5.5288 5.5397 5.5505 5.5613 5.5721 5.5828 5.5934 5.6041 5.6147 5.6252 5.6357 5.6462 5.6567 .008403361 .008333333 .008264463 .008196721 .008130081 .008064516 .008000000 .007936508 .007874016 .007812500 .007751938 .007692308 .007633588 .007575758 .007518797 .007462687 .007407407 .007352941 .007299270 .007246377 .007194245 .007142857 .007092199 .007042254 .006993007 .006944444 .006896552 .006849315 .006802721 .006756757 .006711409 .006666667 .006622517 .006578947 .006535948 .006493506 .006451613 .006410256 .006369427 .006329114 .006289308 .006250000 .006211180 .006172840 .006134969 .006097561 .006060606 .006024096 .005988024 .005952381 .005917160 .005882353 .005847953 .005813953 .005780347 .005747126 .005714286 .005681818 .005649718 .005617978 .005586592 .005555556 .005524862 373.85 376.99 380.13 383.27 386.42 389.56 392.70 395.84 398.98 402.12 405.27 408.41 411.55 414.69 417.83 420.97 424.12 427.26 430.40 433.54 436.68 439.82 442.96 446.11 449.25 452.39 455.53 458.67 461.81 464.96 468.10 471.24 474.38 477.52 480.66 483.81 486.95 490.09 493.23 496.37 499.51 502.65 505.80 508.94 512.08 515.22 518.36 521.50 524.65 527.79 530.93 534.07 537.21 540.35 543.50 546.64 549.78 552.92 556.06 559.20 562.35 565.49 568.63 11,122.02 11,309.73 11.499.01 11.689.87 11,882.29 12,076.28 12.271.85 12,468.98 12,667.69 12,867.96 13,069.81 13,273.23 13,478.22 13,684.78 13,892.91 14.102.61 14.313.88 14,526.72 14,741.14 14,957.12 15,174.68 15,393.80 15.614.50 15,836.77 16.060.61 16.286.02 16.513.00 16.741.55 16.971.67 17,203.36 17,436.62 17,671.46 17.907.86 18,145.84 18,385.39 18.626.50 18.869.19 19.113.45 19,359.28 19.606.68 19,855.65 20.106.19 20,358.31 20,611.99 20,867.24 21.124.07 21.382.46 21.642.43 21,903.97 22.167.08 22,431.76 22.698.01 22,965.83 23,235.22 23,506.18 23,778.71 24,052.82 24,328.49 24,605.74 24.884.56 25,164.94 25,446.90 25.730.43 548 SQUARES, CUBES, SQUARE AND CUBE ROOTS, No . Square. Cube. Sq. Root. Cu. Root. Reciprocal. Circum. Area. 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 33,124 33,489 33,856 34.225 34,596 34,969 35,344 35,721 36.100 36,481 36,864 37,249 37,636 38.025 38,416 38,809 39,204 39,601 40,000 40,401 40,804 41,209 41,616 42.025 42,436 42,849 43,264 43,681 44.100 44,521 44,944 45,369 45,796 46.225 46,656 47,089 47,524 47,961 48,400 48,841 49,284 49,729 50,176 50,625 51,076 51,529 51,984 52,441 52,900 53,361 53,824 54.289 54,756 55.225 55,696 56,169 56,644 57,121 57,600 58,081 58,564 59,049 59,536 6,028,568 6,128,487 6,229,504 6.331.625 6,434,856 6,539,203 6,644,672 6,751,269 6.859.000 6,967,871 7,077,888 7,189,017 7,301,384 7.414.875 7,529,536 7,645,373 7,762,392 7,880,599 8,000,000 8,120,601 8,242,408 8,365,427 8,489,664 8,615,125 8,741,836 8,869,743 8,998,912 9,129,329 9.261.000 9,393,931 9,528.128 9,663,597 9,800,344 9,938,375 10,077,696 10,218,313 10,360,232 10,503,459 10.648.000 10,793,861 10,941,048 11,089,567 11,239,424 11.390.625 11,543,176 11,697,083 11,852,352 12,008,989 12.167.000 12,326,391 12,487,168 12,649,337 12,812,904 12.977.875 13,144,256 13,312,053 13,481,272 13,651,919 13.824.000 13,997,521 14,172,488 14,348,907 14,526,784 13.4907 13.5277 13.5647 13.6015 13.6382 13.6748 13.7113 13.7477 13.7840 13.8203 13.8564 13.8924 13.9284 13.9642 14.0000 14.0357 14.0712 14.1067 14.1421 14.1774 14.2127 14.2478 14.2829 14.3178 14.3527 14.3875 14.4222 14.4568 14.4914 14.5258 14.5602 14.5945 14.6287 14.6629 14.6969 14.7309 14.7648 14.7986 14.8324 14.8661 14.8997 14.9332 14.9666 15.0000 15.0333 15.0665 15.0997 15.1327 15.1658 15.1987 15.2315 15.2643 15.2971 15.3297 15.3623 15.3948 15.4272 15.4596 15.4919 15.5242 15.5563 15.5885 15.6205 5.6671 5.6774 5.6877 5.6980 5.7083 5.7185 5.7287 5.7388 5.7489 5.7590 5.7690 5.7790 5.7890 5.7989 5.8088 5.8186 5.8285 5.8383 5.8480 5.8578 5.8675 5.8771 5.8868 5.8964 5.9059 5.9155 5.9250 5.9345 5.9439 5.9533 5.9627 5.9721 5.9814 5.9907 6.0000 6.0092 6.0185 6.0277 6.0368 6.0459 6.0550 6.0641 6.0732 6.0822 6.0912 6.1002 6.1091 6.1180 6.1269 6.1358 6.1446 6.1534 6.1622 6.1710 6.1797 6.1885 6.1672 6.2058 6.2145 6.2231 6.2317 6.2403 6.2488 .005494505 .005464481 .005434783 .005405405 .005376344 .005347594 .005319149 .005291005 .005263158 .005235602 .005208333 .005181347 .005154639 .005128205 .005102041 .005076142 .005050505 .005025126 .005000000 .004975124 .004950495 .004926108 .004901961 .004878049 .004854369 .004830918 .004807692 .004784689 .004761905 .004739336 .004716981 .004694836 .004672897 .004651163 .004629630 .004608295 .004587156 .004566210 .004545455 .004524887 .004504505 .004484305 .004464286 .004444444 .004424779 .004405286 .004385965 .004366812 .004347826 .004329004 .004310345 .004291845 .004273504 .004255319 .004237288 .004219409 .004201681 .004184100 .004166667 .004149378 .004132231 .004115226 .004098361 571.77 574.91 578.05 581.19 584.34 587.48 590.62 593.76 596.90 600.04 603.19 606.33 609.47 612.61 615.75 618.89 622.04 625.18 628.32 631.46 634.60 637.74 640.88 644.03 647.17 650.31 653.45 656.59 659.73 662.88 666.02 669.16 672.30 675.44 678.58 681.73 684.87 688.01 691.15 694.29 697.43 700.58 703.72 706.86 710.00 713.14 716.28 719.42 722.57 725.71 728.85 731.99 735.13 738.27 741.42 744.56 747.70 750.84 753.98 757.12 760.27 763.41 766.55 26,015.53 26.302.20 26,590.44 26.880.25 27.171.63 27,464.59 27.759.11 28.055.21 28,352.87 28.652.11 28.952.92 29,255.30 29.559.25 29.864.77 30.171.86 30.480.52 30,790.75 31.102.55 31.415.93 31.730.87 32,047.39 32.365.47 32.685.13 33.006.36 33,329.16 33.653.53 33.979.47 34.306.98 34.636.06 34.966.71 35.298.94 35.632.73 35.968.09 36.305.03 36.643.54 36.983.61 37.325.26 37.668.48 38.013.27 38.359.63 38.707.56 39.057.07 39.408.14 39.760.78 40,115.00 40.470.78 40.828.14 41.187.07 41.547.56 41*909.63 42.273.27 42.638.48 43,005.26 43.373.61 43.743.54 44.115.03 44.488.09 44.862.73 45,238.93 45.616.71 45,996.06 46.376.98 46,759.47 CIRCUMFERENCES , AND AREAS. 549 No. Square. Cube. Sq . Root. Cu. Root. Reciprocal. Circum. Area. 245 246 247 248 249 250 251 252 258 254 255 256. 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 60.025 60.516 61.009 61.504 62,001 62,500 63,001 63.504 64.009 64.516 65.025 65.536 66,049 66,564 67,081 67,600 68,121 68,644 69,169 69,696 70.225 70,756 71,289 71,824 72,361 72,900 73,441 73,984 74,529 75,076 75,625 76,176 76,729 77,284 77,841 78.400 78,961 79,524 80,089 80,656 81.225 81,796 82,369 82,944 83,521 84,100. 84,681 85.264 85', 849 86,436 87.025 87,616 88,209 88,804 89.401 90,000 90,601 91,204 91,809 92,416 93.025 93,636 94,249 14,706,125 14,886,936 15,069,223 15,252,992 15,438,249 15.625.000 15,813,251 16,003,008 16,194,277 16,387,064 16,581,375 16,777,216 16,974,593 17,173,512 17,373,979 17.576.000 17,779,581 17,984,728 18,191,447 18,399,744 18,609,625 18,821,096 19,034,163 19,248,832 19.465,109 19^683,000 19,902,511 20,123,643 20,346,417 20,570,824 20,796,875 21,024,576 21,253,933 21,484,952 21,717,639 21.952.000 22,188,041 22,425,768 22,665,187 22,906,304 23,149,125 23,393,656 23,639,903 23,887,872 24,137,569 24.389.000 24,642,171 24,897,088 25,153,757 25,412,184 25,672,375 25,934,836 26,198,073 26,463,592 26,730,899 27,000,000 27,270,901 27,543,608 27,818,127 28,094,464 28,372,625 28,652,616 28,934,443 15.6525 15.6844 15.7162 15.7480 15.7797 15.8114 15.8430 15.8745 15.9060 15.9374 15.9687 16.0000 16.0312 16.0624 16.0935 16.1245 16.1555 16.1864 16.2173 16.2481 16.2788 16.3095 16.3401 16.3707 16.4012 16.4317 16.4621 16.4924 16.5227 16.5529 16.5831 16.6182 16.6433 16.6783 16.7033 16.7332 16.7631 16.7929 16.8226 16.8523 16.8819 16.9115 16.9411 16.9706 17.0000 17.0294 17.0587 17.0880 17.1172 17.1464 17.1756 17.2047 17.2337 17.2627 17.2916 17.3205 17.3494 17.3781 17.4069 17.4356 17.4642 17.4929 17.5214 6.2573 6.2658 6.2743 6.2828 6.2912 6.2996 6.3080 6.3164 6.3247 6.3330 6.3413 6.3496 6.3579 6.3661 6.3743 6.3825 6.3907 6.3988 6.4070 6.4151 6.4232 6.4312 6.4393 6.4473 6.4553 6.4633 6.4713 6.4792 6.4872 6.4951 6.5030 6.5108 6.5187 6.5265 6.5343 6.5421 6.5499 6.5577 6.5654 6.5731 6.5808 6.5885 6.5962 6.6039 6.6115 6.6191 6.6267 6.6343 6.6419 6.6494 6.6569 6.6644 6.6719 6.6794 6.6869 6.6943 6.7018 6.7092 6.7166 6.7240 6.7313 6.7387 6.7460 .004081633 .004065041 .004048583 .004032258 .004016064 .004000000 .003984064 .003968254 .003952569 .003937008 .003921569 .003906250 .003891051 .003875969 .003861004 .003846154 .003831418 .003816794 .003802281 .003787879 .003773585 .003759398 .003745318 .003731343 .003717472 .003703704 .003690037 .003676471 .003663004 .003649635 .003636364 .003623188 .003610108 .003597122 .003584229 .003571429 .003558719 .003546099 .003533569 .003522127 .003508772 .003496503 .003484321 .003472222 .003460208 .003448276 .003436426 .003424658 .003412969 .003401361 .003389831 .003378378 .003367003 .003355705 .003344482 .003333333 .003322259 .003311258 .003301330 .003289474 .003278689 .003267974 .003257329 769.69 772.83 775.97 779.11 782.26 785.40 788.54 791.68 794.82 797.96 801.11 804.25 807.39 810.53 813.67 816.81 819.96 823.10 826.24 829.38 832.52 835.66 838.81 841.95 845.09 848.23 851.37 854.51 857.65 860.80 863.94 867.08 870.22 873.36 876.50 879.65 882.79 885.93 889.07 892.21 895.35 898.50 901.64 904.78 907.92 911.06 914.20 917.35 920.49 923.63 926.77 929.91 933.05 936.19 939.34 942.48 945.62 948.76 951.90 955.04 958.19 961.33 964.47 47.143.52 47,529.16 47,916.36 48,305.13 48,695.47 49,087.39 49.480.87 49.875.92 50.272.55 50.670.75 51.070.52 51,471.85 51.874.76 52.279.24 52,685.29 53.092.92 53.502.11 53.912.87 54.325.21 54.739.11 55,154.59 55,571.63 55.990.25 56,410.44 56,832.20 57.255.53 57.680.43 58,106.90 58,534.94 58.964.55 59.395.74 59.828.49 60,262.82 60,698.71 61.136.18 61.575.22 62.015.82 62,458.00 62.901.75 63.347.07 63,793.97 64.242.43 64,692.46 65.144.07 65,597.24 66.051.99 66,508.30 66.966.19 67.425.65 67,886.68 68,349.28 68.813.45 69.279.19 69.746.50 70,215.38 70.685.83 71,157.86 71.631.45 72,106.62 72,583.36 73.061.66 73,541.54 74.022.99 550 SQUARES, CUBES , SQUARE AND CUBE ROOTS , No. Square. Cube. Sq . Root. Cu. Root. Reciprocal. Circum. Area. 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 94,864 95,481 96,100 96,721 97,344 97,969 98,596 99,225 99,856 100,489 101,124 101,761 102,400 103,041 103,684 104,329 104,976 105,625 106,276 106,929 107,584 108,241 108.900 109,561 110.224 110,889 111,556 112.225 112,896 113,569 114,244 114,921 115.600 116,281 116,964 117,649 118,336 119.025 119,716 120,409 121,104 121,801 122,500 123,201 123,904 124,609 125,316 126.025 126,736 127,449 128,164 128,881 129.600 130,321 131,044 131,769 132,496 133.225 133,956 134,689 135,424 136,161 136.900 29,218,112 29,503,629 29.791.000 30,080,231 30,371,328 30,664,297 30,959,144 31.255.875 31,554,496 31,855,013 32,157,432 32,461,759 32.768.000 33,076,161 33,386,248 33,698,267 34,012,224 34.328.125 34.645.976 34,965,783 35,287,552 35,611,289 35.937.000 36,264,691 36,594,368 36,926,037 37,259,704 37,595,375 37,933,056 38,272,753 38,614,472 38,958,219 39.304.000 39,651,821 40,001,688 40,353,607 40,707,584 41,063,625 41,421,736 41,781,923 42,144,192 42,508,549 42.875.000 43,243,551 43,614,208 43.986.977 44,361,864 44.738.875 45,118,016 45,499,293 45,882,712 46,268,279 46.656.000 47,045,881 47,437,928 47,832,147 48,228,544 48.627.125 49,027,896 49,430,863 49,836,032 50,243,409 50.653.000 17.5499 17.5784 17.6068 17.6352 17.6635 17.6918 17.7200 17.7482 17.7764 17.8045 17.8326 17.8606 17.8885 17.9165 17.9444 17.9722 18.0000 18.0278 18.0555 18.0831 18.1108 18.1384 18.1659 18.1934 18.2209 18.2483 18.2757 18.3030 18.3303 18.3576 18.3848 18.4120 18.4391 18.4662 18.4932 18.5203 18.5472 18.5742 18.6011 18.6279 18.6548 18.6815 18.7083 18.7350 18.7617 18.7883 18.8149 18.8414 18.8680 18.8944 18.9209 18.9473 18.9737 19.0000 19.0263 19.0526 19.0788 19.1050 19.1311 19.1572 19.1833 19.2094 19.2354 6.7533 6.7606 6.7679 6.7752 6.7824 6.7897 6.7969 6.8041 6.8113 6.8185 6.8256 6.8328 6.8399 6.8470 6.8541 6.8612 6.8683 6.8753 6.8824 6.8894 6.8964 6.9034 6.9104 6.9174 6.9244 6.9313 6.9382 6.9451 6.9521 6.9589 6.9658 6.9727 6.9795 6.9864 6.9932 7.0000 7.0068 7.0136 7.0203 7.0271 7.0338 7.0406 7.0473 7.0540 7.0607 7.0674 7.0740 7.0807 7.0873 7.0940 7.1006 7.1072 7.1138 7.1204 7.1269 7.1335 7.1400 7.1466 7.1531 7.1596 7.1661 7.1726 7.1791 .003246753 .003236246 .003225806 .003215434 .003205128 .003194888 .003184713 .003174603 .003164557 .003154574 .003144654 .003134796 .003125000 .003115265 .003105590 .003095975 .003086420 .003076923 .003067485 .003058104 .003048780 .003039514 .003030303 .003021148 .003012048 .003003003 .002994012 .002985075 .002976190 .002967359 .002958580 .002949853 .002941176 .002932551 .002923977 .002915452 .002906977 .002898551 .002890173 .002881844 .002873563 .002865330 .002857143 .002849003 .002840909 .002832861 .002824859 .002816901 .002808989 .002801120 .002793296 .002785515 .002777778 .002770083 .002762431 .002754821 .002747253 .002739726 .002732240 .002724796 .002717391 .002710027 .002702703 967.61 970.75 973.89 977.04 980.18 983.32 986.46 989.60 992.74 995.88 999.03 1,002.17 1,005.31 1,008.45 1,011.59 1.014.73 1,017.88 1,021.02 1,024.16 1,027.30 1,030.44 1.033.58 1.036.73 1,039.87 1,043.01 1,046.15 1,049.29 1,052.43 1.055.58 1,058.72 1,061.86 1,065.00 1,068.14 1,071.28 1.074.42 1,077.57 1,080.71 1,083.85 1,086.99 1,090.13 1.093.27 1.096.42 1,099.56 1,102.70 1,105.84 1,108.98 1,112.12 1.115.27 1,118.41 1,121.55 1,124.69 1,127.83 1,130.97 1.134.11 1,137.26 1,140.40 1,143.54 1,146.68 1,149.82 1,152.96 1.156.11 1,159.25 1,162.39 74.506.01 74.990.60 75.476.76 75,964.50 76.453.80 76.944.67 77.437.12 77.931.13 78.426.72 78.923.88 79.422.60 79.922.90 80.424.77 80.928.21 81.433.22 81.939.80 82.447.96 82.957.68 83,468.98 83.981.84 84.496.28 85.012.28 85.529.86 86.049.01 86.569.73 87.092.02 87.615.88 88.141.31 88.668.31 89.196.88 89.727.03 90.258.74 90.792.03 91.326.88 91.863.31 92.401.31 92.940.88 93,482.02 94,024.73 94.569.01 95.114.86 95.662.28 96.211.28 96.761.84 97.313.97 97.867.68 98,422.96 98.979.80 99.538.22 100,098.21 100.659.77 101.222.90 101.787.60 102,353.87 102,921.72 103.491.13 104,062.12 104,634.67 105,208.80 105,784.49 106,361.76 106.940.60 107.521.01 CIR C UMEERENCES, AND AREAS. 551 No. Square . Cube. Sq. Root. Cu. Root. Reciprocal. Circum. Area. 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 ’413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 137.641 138,384 139.129 139,876 140,625 141,376 142.129 142,884 143.641 144,400 145,161 145,924 146,689 147,456 148.225 148,996 149,769 150,544 151,321 152.100 152,881 153,664 154,449 155,236 156.025 156,816 157,609 158,404 159,201 160,000 160,801 161,604 162,409 163,216 164.025 164,836 165,649 166,464 167,281 168.100 168,921 169,744 170,569 171,396 172.225 173,056 173,889 174,724 175,561 176,400 177,241 178,084 178,929 179,776 180,625 181,476 182,329 183,184 184,041 184,900 185,761 186,624 187,489 51,064,811 51,478,848 51,895,117 52.313.624 52.734.375 53.157.376 53,582,633 54,010,152 54,439,939 54.872.000 55,306,341 55,742,968 56,181,887 56,623,104 57.066.625 57,512,456 57,960,603 58,411,072 58,863,869 59.319.000 59,776,471 •60,236,288 60,698,457- 61,162,984 61,629,875 62,099,136 62,570,773 63,044,792 63,521,199 64,000,000 64,481,201 64,964,808 65,450,827 65,939,264 66,430,125 66,923,416 67,419,143 67,917,312 68,417,929 68.921.000 69,426,531 69,934,528 70,444,997 70,957,944 71,473,375 71,991,296 72,511,713 73,034,632 73,560,059 74.088.000 74,618,461 75,151,448 75,686,967 76,225,024 76,765,625 77,308,776 77,854,483 78,402,752 78,953,589 79.507.000 80,062,991 80,621,568 81,182,737 19.2614 19.2873 19.3132 19.3391 19.3649 19.3907 19.4165 19.4422 19.4679 19.4936 19.5192 19.5448 19.5704 19.5959 19.6214 19.6469 19.6723 19.6977 19.7231 19.7484 19.7737 19.7990 19.8242 19.8494 19.8746 19.8997 19.9249 19.9499 19.9750 20.0000 20.0250 20.0499 20.0749 20.0998 20.1246 20.1494 20.1742 20.1990 20.2237 20.2485 20.2731 20.2978 20.3224 20.3470 20.3715 20.3961 20.4206 20.4450 20.4695 20.4939 20.5183 20.5426 20.5670 20.5913 20.6155 20.6398 20.6640 20.6882 20.7123 20.7364 20.7605 20.7846 20.8087 7.1855 7.1920 7.1984 7.2048 7.2112 7.2177 7.2240 7.2304 7.2368 7.2432 7.2495 7.2558 7.2622 7.2685 7.2748 7.2811 7.2874 7.2936 7.2999 7.3061 7.3124 7.3186 7.3248 7.3310 7.3372 7.3434 7.3496 7.3558 7.3619 7.3681 7.3742 7.3803 7.3864 7.3925 7.3986 7.4047 7.4108 7.4169 7.4229 7.4290 7.4350 7.4410 7.4470 7.4530 7.4590 7.4650 7.4710 7.4770 7.4829 7.4889 7.4948 7.5007 7.5067 7.5126 7.5185 7.5244 7.5302 7.5361 7.5420 7.5478 7.5537 7.5595 7.5654 .002695418 : .002688172 : .002680965 : .002673797 : .002666667 : .002659574 : .002652520 .002645503 .002638521 .002631579 .002624672 .002617801 .002610966 .002604167 .002597403 .002590674 .002583979 .002577320 .002570694 .002564103 .002557545 .002551020 .002544529 .002538071 .002531646 .002525253 .002518892 .002512563 .002506266 .002500000 .002493766 .002487562 .002481390 .002475248 .002469136 .002463054 .002457002 .002450980 .002444988 .002439024 .002433090 .002427184 .002421308 .002415459 .002409639 .002406846 .002398082 .002392344 .002386635 .002380952 .002375297 .002369668 .002364066 .002358491 .002352941 .002347418 .002341920 .002336449 .002331002 .002325581 .002320186 .002314815 .002309469 1,165.53 ! 1,168.67 : 1.171.81 : 1,174.96 : 1,178.10 : 1,181.24 : 1,184.38 : 1,187.52 : 1,190.66 : 1.193.81 : 1,196.95 : 1,200.09 1,203.23 1,206.37 1,209.51 1.212.65 1,215.80 1,218.94 1,222.08 1.225.22 1,228.36 1.231.50 1.234.65 1,237.79 1,240.93 1,244.07 1,247.21 1.250.35 1.253.50 1,256.64 1,259.78 1,262.92 1,266.06 1,269.20 1.272.35 1,275.49 1,278.63 1,281.77 1,284.91 1,288.05 1.291.19 1,294.34 1,297.48 1,300.62 1,303.76 1,306.90 1.310.04 1.313.19 1,316.33 1,319.47 1,322.61 1,325.75 1,328.89 1.332.04 1,335.18 1,338.32 1,341.46 1,344.60 1,347.74 1,350.88 1,354.03 1,357.17 1,360.31 L 08, 102.99 L 08, 686.54 109.271.66 109, 858.35 110.446.62 111.036.45 111.627.86 112,220.83 112,815.38 113,411.49 114.009.18 114,608.44 115,209.27 115.811.67 116,415.64 117.021.18 117,628.30 118,236.98 118.847.24 119.459.06 120.072.46 120.687.42 121,303.96 121.922.07 122.541.75 123,163.00 123,785.82 124,410.21 125,036.17 125,663.71 126,292.81 126,923.48 127.555.73 128,189.55 128,824.93 129,461.89 130.100.42 130,740.52 131.382.19 132.025.43 132.670.24 133.316.63 133,964.58 134.614.10 135.265.20 135.917.86 136.572.10 137.227.91 137,885.29 138.544.24 139.204.76 139.866.85 140.530.51 141.195.74 141,862.54 142.530.92 143.200.86 143,872.38 144,545.46 145,220.12 145.896.35 146,574.15 147.253.52 552 SQUARES, CUBES, SQUARE AND CUBE ROOTS , | No. Square. Cube. Sq. Root. Cu. Root. Reciprocal. Circum. - Area. 4 B 4 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 i 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 188,356 189,225 190,096 190,969 191,844 192,721 193.600 194,481 195,364 196,249 197,136 198.025 198,916 199,809 200,704 201.601 202,500 203,401 204,304 205,209 206,116 207.025 207,936 208,849 209,764 210,681 , 211,600 212,521 213,444 214,369 215,296 216.225 217,156 218,089 219.024 219,961 220,900 221,841 222,784 223,729 224,676 225,625 226,576 227,529 228,484 229,441 230,400 231,361 232,324 233,289 234,256 235.225 236,196 237,169 238,144 239,121 240,100 241,081 242,064 243,049 244,036 245.025 246,^016 81,746,504 82.312.875 82,881,856 83,453,453 84,027,672 84,604,519 85.184.000 85,766,121 86,350,888 86,938,307 87,528,384 88.121.125 88,716,536 89,314,623 89,915,392 90,518,849 91.125.000 91,733,851 92,345,408 92,959,677 93,576,664 94.196.375 94,818,816 95,443,993 96.071,912 96,702,579 97.336.000 97,972,181 98,611,128 99,252,847 99,897,344 100,544,625 101,194,696 101,847,563 102,503,232 103,161,709 103.823.000 104,487,111 105,154,048 105,823,817 106.496,424 107.171.875 107,850,176 108,531,333 109,215,352 109,902,239 110.592.000 111,284,641 111.980.168 112,678,587 113,379,904 114.084.125 114,791,256 115,501,303 116,214,272 116.930.169 117.649.000 118,370,771 119,095,488 119,823,157 120,553,784 121.287.375 122,023,936 20.8327 20.8567 20.8806 20.9045 20.9284 20.9523 20.9762 21.0000 21.0238 21.0476 21.0713 21.0950 21.1187 21.1424 21.1660 21.1896 21.2132 21.2368 21.2603 21.2838 21.3073 21.3307 21.3542 21.3776 21.4009 21.4243 21.4476 21.4709 21.4942 21.5174 21.5407 21.5639 21.5870 21.6102 21.6333 21.6564 21.6795 21.7025 21.7256 21.7486 21.7715 21.7945 21.8174 21.8403 21.8632 21.8861 21.9089 21.9317 21.9545 21.9775 22.0000 22.0227 22.0454 22.0681 22.0907 22.1133 22.1359 22.1585 22.1811 22.2036 22.2261 22.2486 22.2711 7.5712 7.5770 7.5828 7.5886 7.5944 7.6001 7.6059 7.6117 7.6174 7.6232 7.6289 7.6346 7.6403 7.6460 7.6517 7.6574 7.6631 7.6688 7.6744 7.6801 7.6857 7.6914 7.6970 7.7026 7.7082 7.7188 7.7194 7.7250 7.7306 7.7362 7.7418 7.7473 7.7529 7.7584 7.7639 7.7695 7.7750 7.7805 7.7860 7.7915 7.7970 7.8025 7.8079 7.8134 7.8188 7.8243 7.8297 7.8352 7.8406 7.8460 7.8514 7.8568 7.8622 7.8676 7.8730 7.8784 7.8837 7.8891 7.8944 7.8998 7.9051 7.9105 7.9158 .002304147 : .002298851 : .002293578 : .002288330 : .002283105 : .002277904 : .002272727 ! .002267574 : .002262443 .002257336 .002252252 .002247191 .002242152 .002237136 .002232143 .002227171 .002222222 .002217295 .002212389 .002207506 .002202643 .002197802 .002192982 .002188184 .002183406 .002178649 .002173913 .002169197 .002164502 .002159827 .002155172 .002150538 .002145923 .002141328 .002136752 .002132196 .002127660 .002123142 .002118644 .002114165 .002109705 .002105263 .002100840 .002096486 .002092050 .002087683 .002083333 .002079002 .002074689 .002070393 .002066116 .002061856 .002057613 .002053388 .002049180 .002044990 .002040816 .002036660 .002032520 .002028398 .002024291 .002020292 .002016129 1,363.45 : 1,366.59 : 1.369.73 : 1,372.88 : 1,376.02 : 1,379.16 : 1,382.30 : 1,385.44 1.388.58 : 1.391.73 1,394.87 1,398.01 1,401.15 1,404.29 1,407.43 1.410.58 1,413.72 1,416.86 1,420.00 1,423.14 1,426.28 1.429.42 1,432.57 1,435.71 1,438.85 1,441.99 1,445.13 1.448.27 1.451.42 1,454.56 1,457.70 1,460.84 1,463.98 1,467.12 1.470.27 1,473.41 1,476.55 1,479.69 1,482.83 1,485.97 1.489.11 1,492.26 1,495.40 1,498.54 1,501.68 1,504.82 1.507.96 1.511.11 1,514.25 1.517.39 1,520.53 1,523.67 1.526.81 1.529.96 1,533.10 1,536.24 1,539.38 1,542.52 1,545.66 1.548.81 1,551.95 1,555.09 1,558.23 L 47, 934.46 L 48, 616.97 L 49, 301.05 149.986.70 150,673.93 151.362.72 152.053.08 152.745.02 153.438.53 154.133.60 154.830.25 155.528.47 156.228.26 156.929.62 157.632.55 158,337.06 159.043.13 159.750.77 160,459.99 161.170.77 161.883.13 162.597.05 163.312.55 164.029.62 164.748.26 165.468.47 166,190.25 166.913.60 167.638.53 168.365.02 169.093.08 169.822.72 170,553.92 171.286.70 172.021.05 172,756.97 173.494.45 174,233.51 174.974.14 175,716.35 176,460.12 177.205.46 177,952.37 178.700.86 179,450.91 180.202.54 180.955.74 181.710.50 182,466.84 183.224.75 183.984.23 134,745.28 185,507.90 186.272.10 187.037.86 187,805.19 188.574.10 189, 344., 57 190,116.62 190.890.24 191 ,665.43 192,442.18 193.220.51 CIRCUMFERENCES, AND AREAS. 553 No. Square. Cube. Sq. Root. Cu. Root. Reciprocal. Circum. Area. 497 498 499 500 501 502 508 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 247.009 248.004 249,001 250.000 251.001 252.004 253.009 254,016 255,025 256,036 257,049 258,064 259,081 260,100 261,121 262,144 263,169 264,196 265.225 266,256 267,289 268,324 269,361 270,400 271,411 272,484 273,529 274,576 275,625 276,676 277,729 278,784 279,841 280,900 281,961 283.024 284,089 285,156 286.225 287,296 288,369 289,444 290,521 291.600 292,681 293,764 294,849 295,936 297.025 298,116 299,209 300,304 301,401 ' 302,500 303.601 304,704 305,809 306,916 308.025 309,136 310,249 311,364 312,481 122,763,473 123,505,992 124,251,499 125,000,000 125,751,501 126,506,008 127,263,527 128,024,064 128,787,625 129,554,216 130,323,843 131,096,512 131,872,229 132.651.000 133.432.831 134,217,728 135,005,697 135,796,744 136,590,875 137,388,096 138,188,413 138.991.832 139,798,359 140.608.000 141,420,761 142,236,648 143,055,667 143,877,824 144,703,125 145,531,576 146.363.183 147,197,952 148,035,889 148.877.001 149,721,291 150,568,768 151,419,437 152,273,304 153,130,375 153,990,656 154,854,153 155,720,872 156,590,819 157.464.000 158,340,421 159,220,088 160,103,007 160.989.184 161,878,625 162,771,336 163,667,323 164,566,592 165,469,149 166.375.000 167,284,151 168,196,608 169,112,377 170,031,464 170,953,875 171,879,616 172,808,693 173,741.112 174,676,879 22.2935 22.3159 22.3383 22.3607 22.3830 22.4054 22.4277 22.4499 22.4722 22.4944 22.5167 22.5389 22.5610 22.5832 22.6053 22.6274 22.6495 22.6716 22.6936 22.7156 22.7376 22.7596 22.7816 22.8035 22.8254 22.8473 22.8692 22.8910 22.9129 22.9347 22.9565 22.9783 23.0000 23.0217 23.0434 23.0651 23.0868 23.1084 23.1301 23.1517 23.1733 23.1948 23.2164 23.2379 23.2594 23.2809 23.3024 23.3238 23.3452 23.3666 23.3880 23.4094 23.4307 23.4521 23.4734 23.4947 23.5160 23.5372 23.5584 23.5797 23.6008 23.6220 23.6432 7.9211 7.9264 7.9317 7.9370 7.9423 7.9476 7.9528 7.9581 7.9634 7.9686 7.9739 7.9791 7.9843 7.9895 7.9948 8.0000 8.0052 8.0104 8.0156 8.0208 8.0260 8.0311 8.0363 8.0415 8.0466 8.0517 8.0569 8.0620 8.0671 8.0723 8.0774 8.0825 8.0876 8.0927 8.0978 8.1028 8.1079 8.1130 8.1180 8.1231 8.1281 8.1332 8.1382 8.1433 8.1483 8.1533 8.1583 8.1633 8.1683 8.1733 8.1783 8.1833 8.1882 8.1932 8.1982 8.2031 8.2081 8.2130 8.2180 8.2229 8.2278 8.2327 8.2377 .002012072 • : .002008032 : .002004008 : .002000000 : .001996008 ; .001992032 .001988072 : .001984127 : .001980198 .001976285 .001972387 .001968504 .001964637 .001960785 .00L956947 .001953125 .001949318 .001945525 .001941748 .001937984 .001934236 .001930502 .001926782 .001923077 .001919386 .001915709 .001912046 .001908397 .001904762 .001901141 .001897533 .001893939 .001890359 .001886792 .001883239 .001879699 .001876173 .001872659 .001869159 .001865672 .001862197 .001858736 .001855288 .001851852 .001848429 .001845018 .001841621 .001838235 .001834862 .001831502 .001828154 .001824818 .001821494 .041818182 .001814882 .041811594 .001808318 .001805054 .001801802 .001798561 .001795332 .001792115 .001788909 L, 561.37 1 L, 564.51 1 L, 567.65 1 1,570.80 : 1,573.94 : 1,577.08 : 1,580.22 : 1,583.36 : 1.586.50 ! 1,589.65 : 1,592.79 ! 1,595.93 : 1,599.07 : 1,602.21 1,605.35 1.608.50 1,611.64 1,614.78 1,617.92 1,621.06 1,624.20 1.627.34 1,630.49 1,633.63 1,636.77 1,639.91 1,643.05 1.646.19 1.649.34 1,652.48 1,655.62 1,658.76 1,661.90 1.665.04 1.668.19 1,671.33 1,674.47 1,677.61 1,680.75 1,683.89 1.687.04 1,690.18 1,693.32 1,696.46 1,699.60 1,702.74 1.705.88 1,709.03 1,712.17 1,715.31 1,718.45 1,721.59 1.724.73 1.727.88 1,731.02 1,734.16 1,737.30 1,740.44 1,743.58 1.746.73 1,749.87 1,753.01 1,756.15 L94, 000.41 L94, 781.89 L95, 564.93 L96, 349.54 L97, 135.72 L97, 923.48 L98, 712.80 199,503.70 200.296.17 201,090.20 201.885.81 202,682.99 203.481.74 204,282.06 205,083.95 205.887.42 206,692.45 207,499.05 208,307.23 209.116.97 209,928.29 210.741.18 211,555.63 212,371.66 213,189.26 214.008.43 214,829.17 215,651.49 216,475.37 217.300.82 218.127.85 218.956.44 219,786.61 220,618.34 221.451.65 222,286.53 223.122.98 223.961.00 224.800.59 225.641.75 226,484.48 227.328.79 228.174.66 229,022.10 229,871.12 230.721.71 231.573.86 232.427.59 233,282.89 234.139.76 234.998.20 235.858.21 236.719.79 237,582.94 238.447.67 239,313.96 240.181.83 241.051.26 241.922.27 242,794.85 243.668.99 244.544.71 245.422.00 554 SQUARES, CUBES, SQUARE AND CUBE ROOTS, No . Square. Cube. Sq. Root. Cu. Root. Reciprocal. Circum. Area. 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 313,600 314,721 315,844 316,969 318,096 319.225 320,356 321,489 322.624 323,761 324,900 326,041 327,184 328,329 329,476 330.625 331,776 332,929 334,084 335,241 336,400 337,561 338,724 339,889 341,056 342.225 343,396 344,569 345,744 346,921 348.100 349,281 350,464 351,649 352,836 354.025 355,216 356,409 357,604 358,801 360,000 361,201 362,404 363,609 364,816 366.025 367,236 368,449 369,664 370,881 372.100 373,321 374,544 375.769 376,996 378.225 379,456 380,689 381,924 383,161 384,400 385,641 386-884 175.616.000 176,558,481 177,504,328 178,453,547 179,406,144 180.362.125 181,321,496 182,284,263 183,250,432 184,220,009 185.193.000 186,169,411 187,149,248 188,132,517 189,119,224 190,109,375 191,102,976 192,100,033 193,100,552 194,104,539 195.112.000 196,122,941 197,137,368 198,155,287 199,176,704 200,201,625 201,230,056 202,262,003 203,297,472 204,336,469 205.379.000 206,425,071 207,474,688 208,527,857 209,584,584 210,644,875 211,708,736 212,776,173 213,847,192 214,921,799 216,000,000 217,081,801 218,167,208 219,256,227 220,348,864 221.445.125 222,545,016 223.648.543 224,755,712 225,866,529 226.981.000 228,099,131 229,220,928 230,346,397 231.475.544 232,608,375 233,744,896 234,885,113 236,029,032 237,176,659 238.328.000 239,483,061 240,641,848 23.6643 23.6854 23.7065 23.7276 23.7487 23.7697 23.7908 23.8118 23.8328 23.8537 23.8747 23.8956 23.9165 23.^374 23.9583 23.9792 24.0000 24.0208 24.0416 24.0624 24.0832 24.1039 24.1247 24.1454 24.1661 24.1868 24.2074 24.2281 24.2487 24.2693 24.2899 24.3105 24.3311 24.3516 24.3721 24.3926 24.4131 24.4336 24.4540 24.4745 24.4949 24.5153 24.5357 24.5561 24.5764 24.5968 24.6171 24.6374 24.6577 24.6779 24.6982 24.7184 24.7386 24.7588 24.7790 24.7992 24.8193 24.8395 24.8596 24.8797 24.8998 24.9199 24.9399 8.2426 8.2475 8.2524 8.2573 8.2621 8.2670 8.2719 8.2768 8.2816 8.2865 8.2913 8.2962 8.3010 8.3059 8.3107 8.3155 8.3203 8.3251 8.3300 8.3348 8.3396 8.3443 8.3491 8.3539 8.3587 8.3634 8.3682 8.3730 8.3777 8.3825 8.3872 8.3919 8.3967 8.4014 8.4061 8.4108 8.4155 8.4202 8.4249 8.4296 8.4343 8.4390 8.4437 8.4484 8.4530 8.4577 8.4623 8.4670 8.4716 8.4763 8.4809 8.4856 8.4902 8.4948 8.4994 8.5040 8.5086 8.5132 8.5178 8.5224 8.5270 8.5316 8.5362 .001785714 .001782531 .001779359 .001776199 .001773050 .001769912 .001766784 .001763668 .001760563 .001757469 .001754386 .001751313 .001748252 .001745201 .001742164 .001739130 .001736111 .001733102 .001730104 .001727116 .001724138 .001721170 .001718213 .001715266 .001712329 .001709402 .001706485 .001703578 .001700680 .001697793 .001694915 .001692047 .001689189 .001686341 .001683502 .001680672 .001677852 .001675042 .001672241 .001669449 .001666667 .001663894 .001661130 .001658375 .001655629 .001652893 .001650165 .001647446 .001644737 .001642036 .001639344 .001636661 .001633987 .001631321 .001628664 .001626016 .001623377 .001620746 .001618123 .001615509 .001612903 .001610306 .001607717 1,759.29 1,762.43 1,765.58 1,768.72 1,771.86 1,775.00 1,778.14 1,781.28 1.784.42 1,787.57 1,790.71 1,793.85 1,796.99 1,800.13 1.803.27 1.806.42 1,809.56 1,812.70 1,815.84 1,818.98 1,822.12 1.825.27 1,828.41 1,831.55 1,834.69 1.837.83 1,840.97 1.844.11 1,847.26 1,850.40 1,853.54 1,856.68 1,859.82 1.862.96 1.866.11 1,869.25 1,872.39 1,875.53 1,878.67 1,881.81 1.884.96 1,888.10 1,891.24 1,894.38 1,897.52 1,900.66 1,903.81 1,906.95 1,910.09 1,913.23 1,916.37 1,919.51 1.922.65 1,925.80 1,928.94 1,932.08 1,935.22 1,938.36 1,941.50 1.944.65 1,947.79 1,950.93 1,954.07 246.300.86 247.181.30 248.063.30 248.946.87 249.832.01 250.718.73 251.607.01 252.496.87 253.388.30 254,281.29 255,175.86 256,072.00 256,969.71 257.868.99 258.769.85 259.672.27 260.576.26 261.481.83 262.388.96 263,297.67 264.207.94 265,119.79 266.033.21 266,948.20 267,864.76 268,782.89 269.702.59 270.623.86 271,546.70 272,471.12 273,397.10 274,324.66 275,253.78 276.184.48 277,116.75 278,050.58 278.985.99 279.922.97 280,861.52 281.801.65 282,743.34 283.686.60 284,631.44 285.577.84 286,525.82 287,475.36 288.426.48 289.379.17 290.333.43 291.289.26 292.246.66 293,205.63 294.166.17 295.128.28 296.091.97 297.057.22 298.024.05 298.992.44 299,962.41 300.933.95 301.907.05 302.881.73 303.857.98 CIRCUMFERENCES , AND AREAS. 555 No. Square. Cube. Sq. Root. Cu . Root. Reciprocal. Circum. Area. 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 388.129 389,376 390,625 391,876 393.129 394,384 395,641 396,900 398,161 399,424 400,689 401,956 403,225 404,496 405,769 407,044 408,321 409.600 410,881 412,164 413,449 414,736 416,125 417,316 418,609 419,904 421,201 422,500 423,801 425,104 426,409 427,716 429,025 430,336 431,639 432,964 434,281 435.600 436,921 438,244 439,569 440,896 442,225 443,556 444.899 446.224 447,561 448.900 450,241 451,584 452,929 454,276 455,625 456,976 458,329 459,684 461,041 462,400 463,761 465,124 466,489 467,856 469.225 241,804,367 242.970.624 244.140.625 245,314,376 246,491,883 247,673,152 248,858,189 250.047.000 251,239,591 252,435,968 253,636,137 254,840,104 256,047,875 257,259,456 258,474,853 259,694,072 260,917,119 262.144.000 263,374,721 264,609,288 265,847,707 267,089,984 268,336,125 269,585,136 270,840,023 272,097,792 273,359,449 274.625.000 275,894,451 277,167,808 278,445,077 279,726,264 281,011,375 282,300,416 283,593,393 284,890,312 286,191,179 287.496.000 288,804,781 290,117,528 291,434,247 292,754,944 294,079,625 295,408,296 296,740,963 298,077,632 299,418,309 300.763.000 302,111,711 303,464,448 304,821,217 306,182,024 307,546,875 308,915,776 310,288,733 311,665,752 313,046,839 314.432.000 315,821,241 317,214,568 318,611,987 320,013,504 321,419,125 24.9600 24.9800 25.0000 25.0200 25.0400 25.0599 25.0799 25.0998 25.1197 25.1396 25.1595 25.1794 25.1992 25.2190 25.2389 25.2587 25.2784 25.2982 25.3180 25.3377 25.3574 25.3772 25.3969 25.4165 25.4362 25.4558 25.4755 25.4951 25.5147 25.5343 25.5539 25.5734 25.5930 25.6125 25.6320 25.6515 25.6710 25.6905 25.7099 25.7294 25.7488 25.7682 25.7876 25.8070 25.8263 25.8457 25.8650 25.8844 25.9037 25.9230 25.9422 25.9615 25.9808 26.0000 26.0192 26.0384 26.0576 26.0768 26.0960 26.1151 26.1343 26.1534 26.1725 8.5408 8.5453 8.5499 8.5544 8.5589 8.5635 8.5681 8.5726 8.5772 8.5817 8.5862 8.5907 8.5952 8.5997 8.6043 8.6088 8.6132 8.6177 8.6222 8.6267 8.6312 8.6357 8.6401 8.6446 8.6490 8.6535 8.6579 8.6624 8.6668 8.6713 8.6757 8.6801 8.6845 8.6890 8.6934 8.6978 8.7022 8.7066 8.7110 8.7154 8.7198 8.7241 8.7285 8.7329 8.7373 8.7416 8.7460 8.7503 8.7547 8.7590 8.7634 8.7677 8.7721 8.7764 8.7807 8.7850 8.7893 8.7937 8.7980 8.8023 8.8066 8.8109 8.8152 .001605136 .001602564 .001600000 .001597444 .001594896 .001592357 .001589825 .001587302 .001584786 .001582278 .001579779 .001577287 .001574803 .001572327 .001569859 .001567398 .001564945 .001562500 .001560062 .001557632 .001555210 .001552795 .001550388 .001547988 .001545595 .001543210 .001540832 .001538462 .001536098 .001533742 .001531394 .001529052 .001526718 .001524390 .001522070 .001519751 .001517451 .001515152 .001512859 .001510574 .001508296 .001506024 .001503759 .001501502 .001499250 .001497006 .001494768 .001492537 .001490313 .001488095 .001485884 .001483680 .001481481 .001479290 .001477105 .001474926 .001472754 .001470588 .001468429 .001466276 .001464129 .001461988 .001459854 1,957.21 1.960.35 1,963.50 1,966.64 1,969.78 1,972.92 1,976.06 1,979.20 1.982.35 1,985.49 1,988.63 1,991.77 1,994.91 1,998.05 2.001.19 2,004.34 2,007.48 2,010.62 2,013.76 2,016.90 2.020.04 2.023.19 2,026.33 2,029.47 2,032.61 2,035.75 2,038.89 2.042.04 2,045.18 2,048.32 2,051.46 2,054.60 2,057.74 2,060.88 2,064.03 2,067.17 2,070.31 2,073.45 2,076.59 2.079.73 2,082.88 2,086.02 2,089.16 2,092.30 2,095.44 2.098.58 2.101.73 2,104.87 2,108.01 2,111.15 2,114.29 2,117.43 2.120.58 2,123.72 2,126.86 2,130.00 2,133.14 2,136.28 2,139.42 2,142.57 2,145.71 2,148.85 2,151.99 304,835.80 305,815.20 306.796.16 307.778.69 308,762.79 309,748.47 310.735.71 311.724.53 312,714.92 313.706.88 314,700.40 315,695.50 316.692.17 317,690.42 318.690.23 319,691.61 320,694.56 321.699.09 322.705.18 323.712.85 324.722.09 325.732.89 326,745.27 327,759.22 328.774.74 329,791.83 330.810.49 331.830.72 332.852.53 333.875.90 334.900.85 335,927.36 336,955.45 337.985.10 339,016.33 340,049.13 341.083.50 342.119.44 343,156.95 344.196.03 345.236.69 346.278.91 347.322.70 348,368.07 349,415.00 350.463.51 351.513.59 352.565.24 353.618.45 354.673.24 355.729.60 356.787.54 357.847.04 358.908.11 359.970.75 361,034.97 362.100.75 363.168.11 364.237.04 365.307.54 366.379.60 367.453.24 368.528.45 556 SQUARES, CUBES, SQUARE AND CUBE ROOTS, No. Square. Cube. Sq. Root. Cu. Root. Reciprocal. Circum. Area. 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 470,596 471,969 473,344 474,721 476.100 477,481 478,864 480,249 481,636 483.025 484, 4 l 6 485,809 487,204 488,601 490,000 491,401 492,804 494,209 495,616 497.025 498,436 499,849 501,264 502,681 504.100 505,521 506,944 508,369 509,796 511.225 512,656 514,089 515,524 516,961 518,400 519,841 521,284 522,729 524,176 525,625 527.076 528,529 529,984 531,441 532,900 534,361 535,824 537,289 538,756 540.225 541,696 543,169 544,644 546,121 547,600 549,801 550,564 552,049 553,536 555,025 556,516 558,009 559,504 322,828,856 324,242,703 325,660,672 327,082,769 328.509.000 329,939,371 331,373,888 332,812,557 334,255,384 335,702,375 337,153,536 338,608,873 340,068,392 341,532,099 343,000,000' 344,472,101 345,948,408 347,428,927 348,913,664 350,402,625 351,895,816 353,393,243 354,894,912 356,400,829 357.911.000 359,425,431 360,944,128 362,467,097 363,994,344 365,525,875 367,061,696 368,601,813 370,146,232 371,694,959 373.248.000 374,805,361 376,367,048 377,933,067 379,503,424 381,078,125 382,657,176 384,240,583 385,828,352 387,420,489 389.017.000 390,617,891 392,223,168 393,832,837 395,446,904 397,065,375 398,688,256 400,315,553 401,947,272 403,583,419 405.224.000 406,869,021 408,518,488 410,172,407 411,830,784 413,493,625 415,160,936 416,832,723 418,508,992 26.1916 26.2107 26.2298 26.2488 26.2679 26.2869 26.3059 26.3249 26.3439 26.3629 26.3818 26.4008 26.4197 26.4386 26.4575 26.4764 26.4953 26.5141 26.5330 26.5518 26.5707 26.5895 26.6083 26.6271 26.6458 26.6646 26.6833 26.7021 26.7208 26.7395 26.7582 .26.7769 26.7955 26.8142 26.8328 26.8514 26.8701 26.8887 26.9072 26.9258 26.9444 26.9629 26.9815 27.0000 27.0185 27.0370 27.0555 27.0740 27.0924 27.1109 27.1293 27.1477 27.1662 27.1846 27.2029 27.2213 27.2397 27.2580 27.2764 27.2947 27.3130 27.3313 27.3496 8.8194 8.8237 8.8280 8.8323 8.8366 8.8408 8.8451 8.8493 8.8536 8.8578 8.8621 8.8663 8.8706 8.8748 8.8790 8.8833 8.8875 8.8917 8.8959 8.9001 8.9043 8.9085 8.9127 8.9169 8.9211 8.9253 8.9295 8.9337 8.9378 8.9420 8.9462 8.9503 8.9545 8.9587 8.9628 8.9670 8.9711 8.9752 8.9794 8.9835 8.9876 8.9918 8.9959 9.0000 9.0041 9.0082 9.0123 9.0164 9.0205 9.0246 9.0287 9.0328 9.0369 9.0410 9.0450 9.0491 9.0532 9.0572 9.0613 9.0654 9.0694 9.0735 9.0775 .001457726 ! .001455604 ! .001453488 ! .001451379 ! .001449275 ! .001447178 : .001445087 : .001443001 : .001440922 : .001438849 : .001436782 .001434720 .001432665 .001430615 .001428571 .001426534 .001424501 .001422475 .001420455 .001418440 .001416431 .001414427 .001412429 .001410437 .001408451 .001406470 .001404494 .001402525 .001400560 .001398601 .001396648 .001394700 .001392758 .001390821 .001388889 .001386963 .001385042 .001383126 .001381215 .001379310 .001377410 .001375516 .001373626 .001371742 .001369863 .001367989 .001366120 .001364256 .001362398 .001360544 .001358696 .001356852 .001355014 .001353180 .001351351 .001349528 .001347709 .001345895 .001344086 .001342282 .001340483 .001338688 .001336898 2,155.13 ! 2.158.27 : 2,161.42 I 2,164.56 : 2,167.70 : 2,170.84 : 2,173.98 : 2,177.12 : 2.180.27 : 2,183.41 2,186.55 2,189.69 2,192.83 2,195.97 2.199.11 2,202.26 2,205.40 2,208.54 2,211.68 2,214.82 2.217.96 2.221.11 2,224.25 2,227.39 2,230.53 2,233.67 2.236.81 2.239.96 2,243.10 2,246.24 2,249.38 2,252.52 2,255.66 2.258.81 2,261.95 2,265.09 2,268.23 2,271.37 2,274.51 2.277.65 2,280.80 2,283.94 2,287.08 2,290.22 2,293.36 2.296.50 2.299.65 2,302.79 2,305.93 2,309.07 2,312.21 2,315.35 2.318.50 2,321.64 2,324.78 2,327.92 2,331.06 2,334.20 2,337.34 2,340.49 2,343.63 2,346.77 2,349.91 369,605.23 370.683.59 371.763.51 372,845.00 373.928.07 375.012.70 376,098.91 377,186.68 378,276.03 379,366.95 380.459.44 381,553.50 382,649.13 383,746.33 384,845.10 385.945.44 387,047.36 388.150.84 389.255.90 390.362.52 391.470.72 392.580.49 393,691.82 394.804.73 395.919.21 397.035.26 398,152.89 399.272.08 400.392.84 401.515.18 402.639.08 403,764.56 404.891.60 406.020.22 407,150.41 408,282.17 409.415.50 410.550.40 411,686.87 412.824.91 413.964.52 415.105.71 416,248.46 417.392.79 418,538.68 419.686.15 420.835.19 421.985.79 423,137.97 424.291.72 425,447.04 426.603.94 427.762.40 428,922.43 430,084.03 431,247.21 432.411.95 433.578.27 434.746.16 435,915.62 437,086.64 438,259.24 439.433.41 CIRCUMFERENCES , AND AREAS. 557 No . Square. Cube. Sq. Root. Cu. Root. Reciprocal. Circum. Area. 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 561.001 562,500 564.001 565,504 567,009 568,516 570,025 571,536 573,049 574,564 576,081 577,600 579,121 580,644 582,169 583,696 585.225 586,756 588,289 589,824 591,361 592,900 594,441 595,984 597,529 599,076 600,625 602,176 603,729 605,284 606,841 608.400 609,961 611,524 613,089 614,656 616.225 617,796 619,369 620,944 622,521 624.100 625,681 627,264 628,849 630,436 632.025 633,616 635,209 636.804 638.401 640,000 641,601 643,204 644,809 646,416 648.025 649,636 651,249 652,864 654,481 656.100 657,721 420,189,749 . 421,875,000 423,564,751 425,259,008 426,957,777 428,661,064 430,368,875 432,081,216 433,798,093 435,519,512 437,245,479 438.976.000 440,711,081 442,450,728 444,194,947 445,943,744 447,697,125 449,455,096 1 451,217,663 452,984,832 454,756,609 456.533.000 458,314,011 460,099,648 461,889,917 463,684,824 465,484,375 467,288,576 469,097,433 470,910,952 472,729,139 474.552.000 476,379,541 478,211,768 480,048,687 481,890,304 483,736,625 485,587,656 487,443,403 489,303,872 491,169.069 493.039.000 494,913,671 496,793,088 498,677,257 500,566,184 502,459,875 504,358,336 506,261,573 508,169,592 510,082,399 512,000,000 513,922,401 515,849,608 517,781,627 519,718,464 521,660,125 523,606,616 525,557,943 527,514,112 529,475,129 531.441.000 533,411,731 27.3679 27.3861 27.4044 27.4226 27.4408 27.4591 27.4773 27.4955 27.5136 27.5318 27.5500 27.5681 27.5862 27.6043 27.6225 27.6405 27.6586 27.6767 27.6948 27.7128 27.7308 27.7489 27.7669 27.7849 27.8029 27.8209 27.8388 27.8568 27.8747 27.8927 27.9106 27.9285 27.9464 27.9643 27.9821 28.0000 28.0179 28.0357 28.0535 28.0713 28.0891 28.1069 28.1247 28.1425 28.1603 28.1780 28.1957 28.2135 28.2312 28.2489 28.2666 28.2843 28.3019 28.3196 28.3373 28.3549 28.3725 28.3901 28.4077 28.4253 28.4429 28.4605 28.4781 9.0816 9.0856 9.0896 9.0937 9.0977 9.1017 9.1057 9.1098 9.1138 9.1178 9.1218 9.1258 9.1298 9.1338 9.1378 9.1418 9.1458 9.1498 9.1537 9.1577 9.1617 9.1657 9.1696 9.1736 9.1775 9.1815 9.1855 9.1894 9.1933 9.1973 9.2012 9.2052 9.2091 9.2130 9.2170 9.2209 9.2248 9.2287 9.2326 9.2365 9.2404 9.2443 9.2482 9.2521 9.2560 9.2599 9.2638 9.2677 9.2716 9.2754 9.2793 9.2832 9.2870 9.2909 9.2948 9.2986 9.3025 9.3063 9.3102 9.3140 9.3179 9.3217 9.3255 .001335113 : .001333333 ! .001331558 ! .001329787 ! .001328021 ! .001326260 ! .001324503 : .001322751 : .001321004 : .001319261 : .001317523 .001315789 .001314060 .001312336 .001310616 .001308901 .001307190 .001305483 .001303781 .001302083 .001300390 .001298701 .001297017 .001295337 .001293661 .001291990 .001290323 .001288660 .001287001 .001285347 .001283697 .001282051 .001280410 .001278772 .001277139 .001275510 .001273885 .001272265 .001270648 .001269036 .001267427 .001265823 .001264223 .001262626 .001261034 .001259446 .001257862 .001256281 .001254705 .001253133 .001251364 .001250000 .001248439 .001246883 .001245330 .001243781 .001242236 .001240695 .001239157 .001237624 .001236094 .001234568 .001233046 2,353.05 < 2.356.19 < 2,359.34 < 2,362.48 < 2,365.62 - 2,368.76 < 2,371.90 - 2.375.04 • 2.378.19 ■ 2,381.33 • 2,384.47 ■ 2,387.61 2,390.75 2,393.89 2.397.04 2,400.18 2,403.32 2,406.46 2,409.60 2,412.74 2.415.88 2,419.03 2,422.17 2,425.31 2,428.45 2,431.59 2.434.73 2.437.88 2,441.02 2,444.16 2,447.30 2,450.44 2.453.58 2.456.73 2,459.87 2,463.01 2,466.15 2,469.29 2,472.43 2.475.58 2,478.72 2,481.86 2,485.00 2,488.14 2,491.28 2.494.42 2,497.57 2,500.71 2,503.85 2,506.99 2,510.13 2.513.27 2.516.42 2,519.56 2,522.70 2,525.84 2,528.98 2,532.12 2.535.27 2,538.41 2,541.55 2,544.69 2,547.83 140,609.16 141,786.47 142,965.35 144.145.80 445.327.83 446,511.42 447,696.59 448,883.32 450.071.63 451,261.51 452.452.96 453,645.98 454.840.57 456.036.73 457,234.46 458.433.77 459.634.64 460,837.08 462,041.10 463.246.69 464.453.84 465.662.57 466,872.87 468.084.74 469.298.18 470.513.19 471.729.77 472,947.92 474.167.65 475.388.94 476.611.81 477.836.24 479.062.25 480.289.83 481.518.97 482.749.69 483.981.98 485.215.84 486.451.28 487.688.28 488.926.85 490.166.99 491,408.71 492.651.99 493.896.85 495.143.28 496,391.27 497,640.84 498,891.98 500.144.69 501,398.97 502.654.82 503.912.25 505,171.24 506,431.80 507.693.94 508,957.64 510,222.92 511,489.77 5^2,758.19 514,028.18 515,299.74 516,572.87 558 SQUARES , CUBES , SQUARE AND CUBE ROOTS, No. Square. Cube. Sq. Root. Cu. Root. Reciprocal. Circum. Area. 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 659,344 660,969 662,596 664.225 665,856 667,489 669,124 670,761 672,400 674,041 675.584 677,329 678,976 680,625 682,276 683,929 685.584 687,241 688.900 690.561 692.224 693,889 695,556 697.225 698,896 700,569 702,244 703,921 705.600 707,281 708,964 710,649 712,336 714.025 715,716 717,409 719,104 720,801 722,500 724,201 725,904 727,609 729,316 731.025 732,736 734,449 736,164 737,881 739.600 741,321 * 743,044 744,769 746,496 748/225 749,956 751,689 753,424 755,161 756.900 758,641 760,384 762,129 763,876 1 535,387,328 537,367,797 539,353,144 541.343.375 543,338.496 545,338,513 547,343,432 549,353,259 551.368.000 553,387,661 555,412,248 557,441,767 559,476,224 561.515.625 563,559,976 565,609,283 567,663,552 569,722,789 571.787.000 573.856.191 575,930,368 578,009,537 580,093,704 582,182,875 584,277,056 586,376,253 588,480,472 590,589,719 592.704.000 594,823,321 596,947,688 599,077,107 601,211,584 603,351,125 605.495,736 607,645,423 609.800.192 611,960,049 614.125.000 616,295,051 618,470,208 620,650,477 622,835,864 625.026.375 627,222,016 629,422,793 631,628,712 633,839,779 636.056.000 638,277,381 640,503,928 642,735,647 644,972,544 647.214.625 649,461,896 651,714,363 653,972,032 656,234,909 658.503.000 660,776,311 663,054,848 665,338,617 667,627,624 28.4956 28.5132 28.5307 28.5482 28.5657 28.5832 28.6007 28.6182 28.6356 28.6531 28.6705 28.6880 28.7054 28.7228 28.7402 28.7576 28.7750 28.7924 28.8097 28.8271 28.8444 28.8617 28.8791 28.8964 28.9137 28.9310 28.9482 28.9655 28.9828 29.0000 29.0172 29.0345 29.0517 29.0689 29.0861 29.1033 29.1204 29.1376 29.1548 29.1719 29.1890 29.2062 29.2233 29.2404 29.2575 29.2746 29.2916 29.3087 29.3258 29.3428 29.3598 29.3769 29.3939 29.4109 29.4279 29.4449 29.4618 29.4788 29.4958 29.5127 29.5296 29.5466 29.5635 9.3294 9.3332 9.3370 9.3408 9.3447 9.3485 9.3523 9.3561 9.3599 9.3637 9.3675 9.3713 9.3751 9.3789 9.3827 9.3865 9 3902 9.3940 9.3978 9.4016 9.4053 9.4091 9.4129 9.4166 9.4204 9.4241 9.4279 9.4316 9.4354 9.4391 9.4429 9.4466 9.4503 9.4541 9.4578 9.4615 9.4652 9.4690 9.4727 9.4764 9.4801 9.4838 9.4875 9.4912 9.4949 9.4986 9.5023 9.5060 9.5097 9.5135 9.5171 9.5207 9.5244 9.5281 9.5317 9.5354 9.5391 9.5427 9.5464 9.5501 9.5537 9.5574 9.5610 .001231527 .001230012 .001228501 .001226994 .001225490 .001223990 .001222494 .001221001 .001219512 .001218027 .001216545 .001215067 .001213592 .001212121 .001210654 .001209190 .001207729 .001206273 .001204819 .001203369 .001201923 .001200480 .001199041 .001197605 .001196172 .001194743 .001193317 .001191895 .001190476 .001189061 .001187648 .001186240 .001184834 .001183432 .001182033 .001180638 .001179245 .001177856 .001176471 .001175088 .001173709 .001172333 .001170960 .001169591 .001168224 .001166861 .001165501 .001164144 .001162791 .001161440 .001160093 .001158749 .001157407* .00115606SF .001154734 .001153403 .001152074 .001150748 .001149425 .001148106 .001146789 .001145475 .001144165 2,550.97 2.554.11 2,557.26 2,560.40 2,563.54 2,566.68 2,569.82 2.572.96 2.576.11 2,579.25 2,582.39 2,585.53 2,588.67 2.591.81 2.594.96 2,598.10 2,601.24 2,604.38 2,607.52 2,610.66 2.613.81 2,616.95 2,620.09 2,623.23 2,626.37 2,629.51 2.632.65 2,635.80 2,638.94 2,642.08 2,615.22 2,648.36 2.651.50 2.654.65 2,657.79 2,660.93 2,664.07 2,667.21 2,670.35 2.673.50 2,676.64 2.679.78 2,682.92 2,686.06 2,689.20 2.692.34 2,695.49 2,698.63 2,701.77 2,704.91 2,708.05 2.711.19 2.714.34 2,717.48 2,720.62 2,723.76 2,726.90 2,730.04 2.733.19 2,736.33 2,739.47 2,742.61 2,745.75 517.847.57 519.123.84 520.401.68 521,681.10 522,962.08 524,244.63 525.528.76 526.814.46 528,101.73 529,390.56 530,680.97 531.972.95 533.266.50 534.561.62 535,858.32 537.156.58 538.456.41 539.757.82 541,060.79 542,365.34 543.671.46 544.979.15 546,288.40 547,599.23 548.911.63 550,225.61 551.541.15 552,858.26 554,176.94 555.497.20 556.819.02 558.142.42 559,467.39 560,793.92 562.122.03 563.451.71 564.782.96 566,115.78 567,450.17 568.786.14 570,123.67 571.462.77 572,803.45 574.145.69 575.489.51 576,834.90 578.181.85 579.530.38 580,880.48 582.232.15 583.585.39 584.940.20 586.296.59 587,654.54 589,014.07 590.375.16 591.737.83 593,102.06 594.467.87 595,835.25 597.204.20 598.574.72 599,946.81 CIRCUMFERENCES, AND AREAS. 559 No. Square. Cube. 3q. Root. < Du. Root. Reciprocal. Circum. Area. 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 924 925 926 927 928 929 930 931 932 933 934 935 936 937 765,625 767,376 769,129 770,884 772,641 774,400 776,161 777,924 779,689 781,456 783,225 784,996 786,769 788,544 790,321 792.100 793,881 795,664 797,449 799,236 801.025 802,816 804,609 806,404 808,201 810,000 811,801 813,604 815,409 817,216 819.025 820,836 822,649 824,464 826,281 828.100 829,921 831,744 833,569 835,396 837.225 839,056 840,889 842,724 844,561 846,400 848,241 850,084 851,929 853,776 855,625 857,476 859,329 861,184 863,041 884,900 866,761 868,624 870,489 872,356 874.225 876,096 877,969 669,921,875 672,221,376 674,526,133 676,836,152 679,151,439 681.472.000 683,797.841 686,128,968 688,465,387 690,807,104 693,154,125 695,506,456 697,864,103 700,227,072 702,595,369 704.969.000 707,347,971 707,932,288 712,121,957 714,516,984 716,917,375 719,323,136 721,734,273 724,150,792 726,572,699 729,000,000 731,432,701 733,870,808 736,314,327 738,763,264 741,217,625 743,677,416 746,142,643 748,613,312 751,089,429 753.571.000 756,058,031 758,550,825 761,048,497 763,551,944 766,060,875 768,575,296 771,095,213 773,620,632 776,151,559 778.688.000 781,229,961 783.777,448 786^330,467 788,889,024 791,453,125 794,022,776 796,597,983 799,178,752 801,765,089 804.357.000 806,954,491 809,557,568 812,166,237 814,780,504 817,400,375 820,025,856 822,656,953 29.5804 29.5973 29.6142 29.6311 29.6479 29.6648 29.6816 29.6985 29.7153 29.7321 29.7489 29.7658 29.7825 29.7993 29.8161 29.8329 29.8496 29.8664 29.8831 29.8998 29.9166 29.9333 29.9500 29.9666 29.9833 30.0000 30.0167 30.0333 30.0500 30.0666 30.0832 30.0998 30.1164 30.1330 30.1496 30.1662 30.1828 30.1993 30.2159 30.2324 30.2490 30.2655 30.2820 30.2985 30.3150 30.3315 30.3480 30.3645 30.3809 30.3974 30.4138 30.4302 30.4467 30.4631 30.4795 30.4959 30.5123 30.5287 30.5450 30.5614 30.5778 30.5941 30.6105 9.5647 9.5683 9.5719 9.5756 9.5792 9.5828 9.5865 9.5901 9.5937 9.5973 9.6010 9.6046 9.6082 9.6118 9.6154 9.6190 9.6226 9.6262 9.6298 9.6334 9.6370 9.6406 9.6442 9.6477 9.6513 9.6549 9.6585 9.6620 9.6656 9.6692 9.6727 9.6763 9.6799 9.6834 9.6870 9.6905 9.6941 9.6976 9.7012 9.7047 9.7082 9.7118 9.7153 9.7188 9.7224 9.7259 9.7294 9.7329 9.7364 9.7400 9.7435 9.7470 9.7505 ■ 9.7540 9.7575 9.7610 9.7645 9.7680 9.7715 9.7750 9.7785 9.7829 9.7854 .001142857 S .001141553 5 .001140251 5 .001138952 5 .001137656 5 .001136364 i .001135074 5 .001133787 5 .001132503 i .001131222 ! .001129944 i .001128668 i .001127396 ! .001126126 : .001124859 ! .001123596 ! .001122334 : .001121076 .001119821 .001118568 .001117818 .001116071 .001114827 .001113586 .001112347 .001111111 .001109878 .001108647 .001107420 .001106195 .001104972 .001103753 .001102536 .001101322 .001100110 .001098901 .001091695 .001096491 .001095290 .001094092 .001092896 .001091703 .001090513 .001089325 .001088139 .001086957 .001085776 .001084599 .001083423 .001082251 .001081081 .001079914 .001078749 .001077586 .001076426 .001075269 .001074114 .001072961 .001071811 .001070664 .001069519 .001068376 .001067236 >,748.89 ( 5,752.04 e 5,755.18 ( 5,758.32 ( 5,761.46 ( 5,764.60 ( 5,767.74 ( 5.770.88 ( 5,774.03 ( 5,777.17 < 5,780.31 < 5,783.45 < 2,786.59 i 2.789.73 i 2.792.88 i 2,796.02 1 2,799.16 i 2,802.30 2,805.44 2.808.58 2.811.73 2,814.87 2,818.01 2,821.15 2,824.29 2,827.43 2.830.58 2,833.72 2,836.86 2,840.00 2,843.14 2,846.28 2.849.42 2,852.57 2,855.71 2,858.85 2,861.99 2,865.13 2.868.27 2.871.42 2,874.56 2,877.70 2,880.84 2,883.98 2.887.12 2.890.27 2,893.41 2,896.55 2,899.69 2,902.83 2,905.97 2.909.11 2,912.26 2,915.40 2,918.54 2,921.68 2,924.82 2,927.96 2.931.11 2,934.25 2,937.39 2,940.53 2,943.67 >01,320.47 >02,695.70 >04,072.50 >05,450.88 >06,830.82 >08,212.34 >09,595.42 >10,980.08 312,366.31 313,754.11 515.143.48 516.534.42 517,926.93 519.321.01 620,716.66 622,113.89 623,512.68 624,913.04 626,314.98 627.718.49 629.123.56 630.530.21 631.938.43 633.348.22 634.759.58 636.172.51 637.587.01 639.003.09 640,420.73 641,839.95 *643,260.73 644.683.09 646.107.01 647.532.51 648.959.58 650.388.22 651.818.43 653,250.21 654.683.56 656,118.48 657,554.98 658,993.04 660.432.68 661,873.88 663,316.66 664.761.01 666,206.92 667.654.41 669,103.47 670.554.10 672,006.30 673,460.08 674.915.42 676,372.33 677,830.82 679,290.87 680,752.50 682.215.69 683,680.46 685,146.80 686,614.71 , 688,084.19 689,555.24 560 SQUARES , CUBES, SQUARE AND CUBE ROOTS , No. Square. Cube. Sq. Root. Cu. Root. Reciprocal. Circum. Area. 938 939 940 941 942 943 944 945 946 947 948 949 950 951 952 953 954 955 956 957 958 959 960 961 962 963 964 965 966 967 968 969 970 971 972 973 974 975 976 977 978 979 980 981 982 983 984 985 986 987 . 988 989 990 991 992 993 994 995 996 997 998 999 1000 879,844 881,721 883.600 885,481 887,364 889,249 891,136 893.025 894,916 896,808 898,704 900.601 902,500 904,401 906,304 908,209 910,116 912.025 913,936 915,849 917,764 919,681 921,600 923,521 925,444 927,369 929,296 931.225 933,156 935,089 937.024 938,961 940,900 942,841 944,784 946,729 948,676 950,625 952,576 954,529 956,484 958,441 960,400 962,361 964,324 966,289 968,256 970.225 972,196 974,169 976,144 978,121 980,100 982,081 984,064 986,049 988,036 990.025 992,016 994,009 996,004 998,001 1,000,000 825,293,672 827,936,019 830.584.000 833,237,621 835,896,888 838,561,807 841,232,384 843.908.625 846,590,536 849,278,123 851,971,392 854,670,349 857.375.000 860.085.351 862,801,408 865,523,177 868,250,664 870.983.875 873,722,816 876,467,493 879,217,912 881,974,079 884.736.000 887,503,681 890,277,128 893,056,347 895,841,344 898,632,125 901,428,696 904,231,063 907,039,232 909,853,209 912.673.000 915,498,611 918,330,048 921,167,317 924,010,424 926,859,375 929,714,176 932,574,833 935.441.352 938,313,739 941.192.000 944,076,141 946,966,168 949,862,087 952,763,904 955.671.625 958,585,256 961,504,803 964,430,272 967,361,669 970.299.000 973,242,271 976,191,488 979,146,657 982,107,784 985.074.875 988,047,936 991,026,973 994,011,992 997,002,999 1,000,000,000 30.6268 30.6431 30.6594' 30.6757 30.6920 30.7083 30.7246 30.7409 30.7571 30.7734 30.7896 30.8058 30.8221 30.8383 30.8545 30.8707 30.8869 30.9031 30.9192 30.9354 30.9516 30.9677 30.9839 31.0000 31.0161 31.0322 31.0483 31.0644 31.0805 31.0966 31.1127 31.1288 31.1448 31.1609 31.1769 31.1929 31.2090 31.2250 31.2410 31.2570 31.2730 31.2890 31.3050 31.3209 31.3369 31.3528 31.3688 31.3847 31.4006 31.4166 31.4325 31.4484 31.4643 31.4802 31.4960 31.5119 31.5278 31.5436 31.5595 31.5753 31.5911 31.6070 31.6228 9.7889 9.7924 9.7959 9.7993 9.8028 9.8063 9.8097 9.8132 9.8167 9.8201 9.8236 9.8270 9.8305 9.8339 9.8374 9.8408 9.8443 9.8477 9.8511 9.8546 9.8580 9.8614 9.8648 9.8683 9.8717 9.8751 9.8785 9.8819 9.8854 9.8888 9.8922 9.8956 9.8990 9.9024 9.9058 9.9092 9.9126 9.9160 9.9194 9.9228' 9.9261 9.9295 9.9329 9.9363 9.9396 9.9430 9.9464 9.9497 9.9531 9.9565 9.9598 9.9632 9.9666 9.9699 9.9733 9.9766 9.9800 9.9833 9.9866 9.9900 9.9933 9.9967 10.0000 .001066098 .001064963 .001063830 .001062699 .001061571 .001060445 .001059322 .001058201 .001057082 .001055966 .001054852 .001053741 .001052632 .001051525 .001050420 .001049318 .001048218 .001047120 .001046025 .001044932 .001043841 .001042753 .001041667 .001040583 .001039501 .001038422 .001037344 .001036269 .001035197 .001034126 .001033058 .001031992 .001030928 .001029866 .001028807 .001027749 .001026694 .001025641 .001024590 .001023541 .001022495 .001021450 .001020408 .001019168 .001018330 .001017294 .001016260 .001015228 .001014199 .001013171 .001012146 .001011122 .001010101 .001009082 .001008065 .001007049 .001006036 .001005025 .001004016 .001003009 .001002004 .001001001 .001000000 2.946.81 2,949.96 2,953.10 2,956.24 2,959.38 2,962.52 2,965.66 2.968.81 2,971.95 2,975.09 2,978.23 2,981.37 2,984.51 2.987.65 2,990.80 2,993.94 2,997.08 3,000.22 3,003.36 3.006.50 3.009.65 3,012.79 3,015.93 3,019.07 3,022.21 3,025.35 3.028.50 3,031.64 3,034.78 3,037.92 3,041.06 3,044.20 3.047.34 3,050.49 3,053.63 3,056.77 3,059.91 3,063.05 3.066.19 3.069.34 3,072.48 3,075.62 3,078.76 3,081.90 3.085.04 3.088.19 3,091.33 3,094.47 3,097.61 3,100.75 3,103.89 3.107.04 3,110.18 3,113.32 3,116.46 3,119.60 3,122.74 3,125.88 3,129.03 3,132.17 3,135.31 3,138.45 3,141.59 691,027.86 692.502.05 693.977.82 695.455.15 696.934.06 698.414.53 699.896.58 701,380.19 702.865.38 704.352.14 705.840.47 707.330.37 708.821.84 710,314.88 711,809.50 713,305.68 714.803.43 716.302.76 717.803.66 719.306.12 720.810.16 722.315.77 723.822.95 725.331.70 726,842.02 728,353.91 729.867.37 731,382.40 732,899.01 734,417.18 735.936.93 737,458.24 738.981.13 740.505.59 742,031.62 743,559.22 745.088.39 746.619.13 748.151.44 749,685.32 751.220.78 752,757.80 754.296.40 755,836.56 757,378.30 758.921.61 760.466.48 762.012.93 763.560.95 765.110.54 766.661.70 768.214.44 769,768.74 771.324.61 772.882.06 774.441.07 776.001.66 777.563.82 779.127.54 780.692.84 782.259.71 783.828.15 785.398.16 CIRCUMFERENCES AND AREAS OF CIRCLES. 561 CIRCUMFERENCES AND AREAS OF CIRCLES FROM 1-64 TO 100. Diam. Circum. Area. Diam. Circum. Area. Diam. * Circum. Area. i 0491 0002 6 18.8496 28.2744 13} 41.2335 135.297 6* 1 0982 0008 6? 19.2423 29.4648 13} 41.6262 137.887 3l 1 1963 0031 61 19.6350 30.6797 13} 42.0189 140.501 TS 1 3927 0123 6} 20.0277 31.9191 13} 42.4116 143.139 S 3 5890 0276 61 20.4204 33.1831 13} 42.8043 145.802 TS 1 7854 ]0491 6} 20.8131 34.4717 13} 43.1970 148.490 ¥ 5 9817 0767 6} 21.2058 35.7848 13} 43.5897 151.202 TS 3 1 1781 .1104 61 21.5985 37.1224 14 43.9824 153.938 l 1 1 3744 1503 7 21.9912 38.4846 14} 44.3751 156.700 1 5708 1963 7} 22.3839 39.8713 14} 44.7678 159.485 i TS 6 1 7671 2485 71 22.7766 41.2826 14} 45.1605 162.296 1 9635 .3068 7| 23.1693 42.7184 14} 45.5532 165.130 S n 3 2.1598 2 3562 .3712 .4418 71 71 23.5620 23.9547 44.1787 45.6636 14} 14} 45.9459 46.3386 167.990 170.874 ?3 2 5525 .5185 71 24.3474 47.1731 14} 46.7313 173.782 f r 5 2 7489 6013 71 24.7401 48.7071 15 47.1240 176.715 A 2 9452 6903 8 25.1328 50.2656 15} 47.5167 179.673 l 1 3 1416 .7854 81 25.5255 51.8487 15} 47.9094 182.655 1 1 3 5343 .9940 81 25.9182 53.4563 15} 48.3021 185.661 -*-8 1 1 3 9270 1.2272 81 26.3109 55.0884 15} 48.6948 188.692 X 4 1 3 4 3197 1.4849 81 26.7036 56.7451 15} 49.0875 191.748 -•-8 4.7124 1.7671 81 27.0963 58.4264 15} 49.4802 194.828 It 5.1051 2.0739 81 27.4890 60.1322 15} 49.8729 197.933 8 1 3 5.4978 2.4053 81 27.8817 61.8625 16 50.2656 201.062 1- 5.8905 2.7612 9 28.2744 63.6174 16} 50.6583 204.216 1 8 2 6.2832 3.1416 91 28.6671 65.3968 16} 51.0510 207.395 ! 2^ 6.6759 3.5466 91 29.0598 67.2008 16} 51.4437 210.598 21 7.0686 3.9761 91 29.4525 69.0293 16} 51.8364 213.825 7.4613 4.4301 9a - 29.8452 70.8823 16} 52.2291 217.077 "8 21 7.8540 4.9087 91 30.2379 72.7599 16} 52.6218 220.354 "2 21 8.2467 5.4119 91 30.6306 74.6621 16} 53.0145 223.655 21 8.6394 5.9396 91 31.0233 76.589 17 53.4072 226.981 21 9.0321 6.4918 10 31.4160 78.540 17} 53.7999 230.331 "8 3 9.4248 7.0686 101 31.8087 80.516 17} 54.1926 233.706 3i 9.8175 7.6699 101 32.2014 82.516 17} 54.5853 237.105 Br 10.2102 8.2958 101 32.5941 84.541 17} 54.9780 240.529 31 10.6029 8.9462 101 32.9868 86.590 17} 55.3707 243.977 31 10.9956 9.6211 101 33.3795 88.664 17} 55. / 634 247.450 '-'2 31 11.3883 10.3206 101 33.7722 90.763 17} 56.1561 250.948 u 8 31 11.7810 11.0447 101' 34.1649 92.886 18 56.5488 . 254.470 °4 31 12.1737 11.7933 11 34.5576 95.033 18} 56.9415 258.016 4 12.5664 12.5664 111 34.9503 97.205 18} 57.3342 261.587 41 12.9591 13.3641 111 35.3430 99.402 18} 57.7269 265.183 41 13.3518 14.1863 111 35.7357 101.623 18} 58.1196 268.803 A 4 41 13.7445 15.0330 111 36.1284 103.869 18} 58.5123 272.448 ^8 41 14.1372 15.9043 111 36.5211 106.139 18} 58.9050 276.117 41 14.5299 16.8002 111 36.9138 108.434 18} 59.2977 279.811 A 8 41 14.9226 17.7206 111 37.3065 110.754 19 59.6904 283.529 A 4 41 15.3153 18.6555 12 37.6992 113.098 19} 60.0831 287.272 5 15.7080 19.6350 121 38.0919 115.466 19} 60.4758 291.040 51 16.1007 20.6290 121 38.4846 117.859 19} 60.8685 294.832 '"'8 51 16.4934 21.6476 12f 38.8773 120.277 19} 61.2612 298.648 u 4 51 16.8861 22.6907 121 39.2700 122.719 19} 61.6539 302.489 “8 51 17.2788 23.7583 121 39.6627 125.185 19} 62.0466 306.355 51 17.6715 24.8505 121 40.0554 127.677 19} 62.4393 310.245 w 8 51 18.0642 25.9673 121 40.4481 130.192 20 62.8320 314.160 51 18.4569 27.1086 13 40.8408 132.733 20} 63.2247 318.099 562 CIRCUMFERENCES AND AREAS OF CIRCLES. Diam. I Circum. Area. Diam. Circum. Area. Diam. Circum. Area. 20} 63.6174 322.063 28} 88.3575 621.264 36 113.098 1,017.878 20f 64.0101 326.051 28} 88.7502 626.798 36} 113.490 1,024.960 20} 64.4028 330.064 28} 89.1429 632.357 36} 113.8S3 1,032.065 20| 64.7955 334.102 28} 89.5356 637.941 36} 114.276 1,039.195 m 65.1882 338.164 28} 89.9283 643.549 36} 114.668 1.046.349 20} 65.5809 342.250 28} 90.3210 649.182 36} 115.061 1,053.528 21 65.9736 346.361 28} 90.7137 654.840 36} 115.454 1.060.732 21} 66.3663 350.497 29 91.1064 660.521 36} 115.846 1,067.960 21} 66.7590 354.657 29} 91.4991 666.228 37 116.239 1,075.213 21f 67.1517 358.842 29} 91.8918 671.959 37} 116.632 1.082.490 21| 67.5444 363.051 29} 92.2845 677.714 37} 117.025 1,089.792 21} 67.9371 367.285 29} 92.6772 683.494 37} 117.417 1.097.118 21} 68.3298 371.543 29} 93.0699 689.299 37} 117.810 1,104.469 21} 68.7225 375.826 29} 93.4626 695.128 37} 118.203 1,111.844 22 69.1152 380.134 29} 93.8553 700.982 37} 118.595 1,119.244 22} 69.5079 384.466 30 94.2480 706.860 37} 118.988 1.126.669 22} 69.9006 388.822 30} 94.6407 712.763 38 119.381 1.134.118 22} 70.2933 393.203 30} 95.0334 718.690 38} 119.773 1.141.591 22} 70.6860 397.609 30} 95.4261 724.642 38} 120.166 1,149.089 22f 71.0787 402.038 30} 95.8188 730.618 38} 120.559 1.156.612 22} 71.4714 406.494 30} 96.2115 736.619 38} 120.952 1,164.159 22} 71.8641 410.973 30} 96.6042 742.645 38} 121.344 1,171.731 23 72.2568 415.477 30} 96.9969 748.695 38} 121.737 1,179.327 23} 72.6495 420.004 31 97.3896 754.769 38} 122.130 1,186.948 23} 73.0422 424.558 31} 97.7823 760.869 39 122.522 1,194.593 23| 73.4349 429.135 31} 98.1750 766.992 39} 122.915 1.202.263 23} 73.8276 433.737 31} 98.5677 773.140 39} 123.308 1.209.958 23f 74.2203 438.364 31} 98.9604 779.313 39} 123.700 1.217.677 23} 74.6130 443.015 31} 99.3531 785.510 39} 124.093 1,225.420 23} 75.0057 447.690 31} 99.7458 791.732 39} 124.486 1.233.1S8 24 75.3984 452.390 31} 100.1385 797.979 39} 124. 879 1.240.981 24} 75.7911 457.115 32 100.5312 804.250 39} 125.271 1.248.798 24} 76.1838 461.864 32} 100.9239 810.545 40 125.664 1,256.640 24f 76.5765 466.638 32} 101.3166 816.865 40} 126.057 1.264.510 24} 76.9692 471.436 32} 1 101.7093 823.210 40} 126.449 1,272.400 24} 77.3619 476.259 32} 102.1020 829.579 40} 126.842 1,280.310 24} 77.7546 481.107 32} 102.4947 835.972 40} 127.235 1.288.250 24} 78.1473 485.979 32} : 102.8874 842.391 40} 127.627 1.296.220 25 78.5400 490.875 32} 103.280 848.833 40} 128.020 1.304.210 25} 78.9327 495.796 33 103.673 855.301 40} 128.413 1.312.220 25} 79.3254 500.742 33} 104.065 861.792 41 128.806 1.320.260 25} 79.7181 505.712 33} 104.458 868.309 41} 129.198 1.328.320 25} 80.1108 510.706 33} 104.851 874.850 41} 129.591 1.336.410 25} 80.5035 515.726 33} 105.244 881.415 41} 129.984 1.344.520 25} 80.8962 520.769 33} 105.636 888.005 41} 130.376 1.352.660 25} 81.2889 525.838 33} 106.029 894.620 41} 130.769 1.360.820 26 81.6816 530.930 33} 106.422 901.259 41} 131.162 1,369.000 26} 82.0743 536.048 34 106.814 907.922 41} 131.554 1,377.210 26} 82.4670 541.190 34} 107.207 914.611 42 131.947 1,385.450 26} 82.8597 546.356 34} 107.600 921.323 42} 132.340 1,393.700 26} 83.2524 551.547 34} 107.992 928.061 42} 132.733 1,401.990 26} 83.6451 556.763 84} 108.385 934.822 42} 133.125 1,410.300 26} 84.0378 562.003 34} 108.778 941.609 42} 133.518 1,418.630 26} 84.4305 567.267 34} 109.171 948.420 42} 133.911 1.426.990 27 84.8232 572.557 34} 109.563 955.255 42} 134.303 1,435.370 27} 85.2159 577.870 35 109.956 962.115 42} 134.696 1.443.770 27} 85.6086 583.209 35} 110.349 969.000 43 135.089 1.452.200 27} 86.0013 588.571 35} 110.741 975.909 43} -! 135.481 1,460.660 27} 86.3940 593.959 35} 111.134 982.842 43} 135.874 1.469.140 27} 86.7867 599.371 35} 111.527 989.800 43} 136.267 1,477.640 27} 87.1794 604.807 35} 111.919 996.783 43} 136.660 1,486.170 27} 87.5721 610.268 35} 112.312 1,003.790 43} 137.052 1,494.730 28 87.9648 615.754 35} 112.705 1,010.822 43} 137.445 1,503.300 CIRCUMFERENCES AND AREAS OF CIRCLES. 563 Diam. Circum. Area. Diam. Circum. Area. Diam. Circum. Area. 43! 44 44| 44! 44! 44! 44! 44! 44! 45 45! 45! 45f 45! 45| 45! 45! 46 46! 46! 46f 46! 46f 46! 46! 47 47! 47! 47! 47! 47! 47! 47! 48 48! 48! 48! 48! 48! 48! 48! 49 49! 49! 49! 49! 49! 49! 49! 50 50! 50! 50! 50! 50! 50! 50! 51 51! 51! 51! 51! 51| 137.838 138.230 138.623 139.016 139.408 139.801 140.194 140.587 140.979 141.372 141.765 142.157 142.550 142.943 143.335 143.728 144.121 144.514 144.906 145.299 145.692 146.084 146.477 146.870 147.262 147.655 148.048 148.441 148.833 149.226 149.619 150.011 150.404 150.797 151.189 151.582 151.975 152.368 152.760 153.153 153.546 153.938 154.331 154.724 155.116 155.509 155.902 156.295 156.687 157.080 157.473 157.865 158.258 158.651 159.043 159.436 159.829 160.222 160.614 161.007 161.400 161.792 162.185 1,511.910 1,520.530 1,529.190 1,537.860 ' 1,546.56 1,555.29 1.564.04 1,572.81 1,581.61 1,590.43 1,599.28 1,608.16 1.617.05 1,625.97 1,634.92 1.643.89 1.652.89 1,661.91 1.670.95 1,680.02 1,689.11 1,698.23 1.707.37 1.716.54 1.725.73 1.734.95 1,744.19 1.753.45 1.762.74 1.772.06 1,781.40 1,790.76 1.800.15 1,809.56 1,819.00 1.828.46 1.837.95 1.847.46 1,856.99 1.866.55 1,876.14 1.885.75 1.895.38 1,905.04 1,914.72 1,924.43 1.934.16 1,943.91 1,953.69 1,963.50 1,973.33 1,983.18 1,993.06 2.002.97 2.012.89 2.022.85 2.032.82 2.042.83 2.052.85 2.062.90 2.072.98 2,083.08 2,093.20 51! 51! 52 52! 52! 52! 52! 52! 52! 52! 53 53! 53! 53! 53! 53! 53! 53! 54 54! 54! 54! 54! 54! 54! 54! 55 55! 55! 55! 55! | 55! 55! 55! 56 56! 56! 56! 56! 56! 56! 56! 57 57! 57! 57! 57! 57! 57! 57! 58 58! 58! 58! 58! 58! 58! 58! 59 59! 59! 59! 59! 162.578 162.970 163.363 163.756 164.149 164.541 164.934 165.327 165.719 166.112 166.505 166.897 167.290 167.683 168.076 168.468 168.861 169.254 169.646 170.039 170.432 170.824 171.217 171.610 172.003 172.395 172.788 173.181 173.573 173.966 174.359 174.751 175.144 175.537 175.930 176.322 176.715 177.108 177.500 177.893 178.286 178.678 179.071 179.464 179.857 180.249 180.642 181.035 181.427 181.820 182.213 182.605 182.998 183.391 183.784 184.176 184.569 184.962 185.354 185.747 186.140 186.532 186.925 2,103.35 2.113.52 2,123.72 2,133.94 2.144.19 2,154.46 2,164.76 2,175.08 2,185.42 2,195.79 2.206.19 2,216.61 2.227.05 2.237.52 2.248.01 2.258.53 2.269.07 2.279.64 2.290.23 2,300.84 2.311.48 2,322.15 2.332.83 2,343.55 2.354.29 2.365.05 2.375.83 2.386.65 2.397.48 2,408.34 2.419.23 2,430.14 2.441.07 2,452.03 2.463.01 2.474.02 2.485.05 2,496.11 2.507.19 2.518.30 2,529.43 2,540.58 2,551.76 2.562.97 2.574.20 2,585.45 2,596.73 2.608.03 2.619.36 2,630.71 2,642.09 2,653.49 2,664.91 2.676.36 2.687.84 2,699.33 2,710.86 2,722.41 2.733.98 2,745.57 2.757.20 2.768.84 2,780.51 59! 59! 59! 60 60! 60! 60! 60! 60! 60! 60! 61 61! 61! 61! 61! 61! 61! 61! 62 62! 62! 62! 62! 62! 62! 62! 63 63! 63! 63! 63! 63! 63! 63! 64 64! 64! 64! 64! 64! 64! 64! 65 65! 65! 65! 65! 65! 65! 65! 66 66! 66! 66! 66! 66! 66! 66! 67 67! 67! 67! 187.318 187.711 188.103 188.496 188.889 189.281 189.674 190.067 190.459 190.852 191.245 191.638 192.030 192.423 192.816 193.208 193.601 193.994 194.386 194.779 195.172 195.565 195.957 196.350 196.743 197.135 197.528 197.921 198.313 198.706 199.099 199.492 199.884 200.277 200.670 201.062 201.455 201.848 202.240 202.633 203.026 203.419 203.811 204.204 204.597 204.989 205.382 205.775 206.167 206.560 206.953 207.346 207.738 208.131 208.524 208.916 209.309 209.702 210.094 210.487 210.880 211.273 211.665 2,792.21 2,803.93 2.815.67 2,827.44 2,839.23 2,851.05 2.862.89 2,874.76 2,886.65 2.898.57 2.910.51 2.922.47 2.934.46 2.946.48 2.958.52 2.970.58 2.982.67 2,994.78 3.006.92 3,019.08 3,031.26 3.043.47 3,055.71 3,067.97 3.080.25 3.092.56 3.104.89 3.117.25 3,129.64 3,142.04 3.154.47 3.166.93 3,179.41 3,191.91 3.204.44 3,217.00 3.229.58 3.242.18 3,254.81' 3,267.46 3,280.14 3,292.84 3.305.56 3,318.31 3,331.09 3.343.89 3,356.71 3.369.56 3.382.44 3,395.33 3,408.26 3,421.20 3.434.17 3.447.17 3.460.19 3.473.24 3,486.30 3,499.40 3,512.52 3,525.66 3,538.83 3,552.02 3.565.24 564 CIRCUMFERENCES AND AREAS OF CIRCLES. Diam. Circum. Area. Diam. Circum. Area. | Diam. Circum. Area. m 1 212.058 3,578.48 75# 236.798 4,462.16 83# 261.538 5,443.26 67# 212.451 3,591.74 75# 237.191 4,476.98 83# 261.931 5,459.62 67# 212.843 3,605.04 75# 237.583 4,491.81 83# 262.324 5,476.01 67# 213.236 3,618.35 75# 237.976 4,506.67 83# 262.716 5,492.41 68 213.629 3,631.69 75# 238.369 4,521.56 83# 263.109 5,508.84 68# 214.021 3,645.05 76 238.762 4,536.47 83# 263.502 5,525.30 68# 214.414 3,658.44 76# 239.154 4,551.41 84 263,894 5,541.78 68# 214.807 3,671.86 76# 239.547 4,566.36 84# 264.287 5,558.29 68# 215.200 3,685.29 76# 239.940 4,581.35 84# 264.680 5,574.82 68 1 215.592 3,698.76 76# 240.332 4,596.36 84# 265.072 5,591.37 68# 215.985 3,712.24 76# 240.725 4,611.39 84# 265.465 5,607.95 68# 216.378 3,725.75 76# 241.118 4,626.45 84# 265.858 5,624.56 69 216.770 3,739.29 76# 241.510 4,641.53 84# 266.251 5,641.18 69# 217.163 3,752.85 77 241.903 4,656.64 84# 266.643 5,657.84 m 217.556 3,766.43 771 242.296 4,671.77 85 267.036 5,674.51 69# 217.948 3,780.04 77# 242.689 4,686.92 85# 267.429 5,691.22 69# 218.341 3,793.68 77# 243.081 4,702.10 85# 267.821 5,707.94 69# 218.734 3,807.34 77# 243.474 4,717.31 85# 268.214 5,724.69 69| 219.127 3,821.02 77# 243.867 4,732.54 85# 268.607 5,741.47 69# 219.519 3,834.73 77# 244.259 4,747.79 85# 268.999 5,758.27 70 219.912 3,848.46 77# 244.652 4,763.07 85# 269.392 5,775.10 70# 220.305 3,862.22 78 245.045 4,778.37 85# 269.785 5,791.94 70# 220.697 3,876.00 78# 245.437 4,793.70 86 270.178 5,808.82 701 221.090 3,889.80 78# 245.830 4,809.05 86# 270.570 5,825.72 70# 221.483 3,903.63 78# 246.223 4,824.43 86# 270.963 5,842.64 70# 221.875 3,917.49 78# 246.616 4,839.83 86# 271.356 5,859.59 70# 222.268 3,931.37 78# 247.008 4,855.26 86# 271.748 5,876.56 70# 222.661 3,945.27 78# 247.401 4,870.71 86# 272.141 5,893.55 71 223.054 3,959.20 78# 247.794 4,886.18 86# 272.534 5,910.58 71# t 223.446 3,973.15 79 248.186 4,901.68 86# 272.926 5,927.62 71# 223.839 3,987.13 79# 248.579 4,917.21 87 273.319 5,944.69 71# t 224.232 4,001.13 79# 248.972 4,932.75 87# 273.712 5,961.79 71# \ 224.624 4,015.16 79# 249.364 4,948.33 87# 274.105 5,978.91 71# \ 225.017 4,029.21 79# 249.757 4,963.92 87# 274.497 5,996.05 71# \ 225.410 4,043.29 79# 250.150 4,979.55 87# 274.890 6,013.22 71# 225.802 4,057.39 79# 250.543 4,995.19 87# 275.283 6,030.41 72 226.195 4,071.51 79# 250.935 5,010.86 87# 275.675 6,047.63 72- ■ 226.588 4,085.66 80 251.328 5,026.56 87# 276.068 6,064.87 72, 226.981 4,099.84 80# 251.721 5,042.28 88 276.461 6,082.14 72 ■ 227.373 4,114.04 80# 252.113 5,058.03 88# 276.853 6,099.43 72- • 227.766 4,128.26 80# 252.506 5,073.79 88# 277.246 6,116.74 72 ■ 228.159 4,142.51 80# 252.899 5,089.59 88# 277.629 6,134.08 72; . 228.551 4,156.78 80# 253.291 5,105.41 88# 278.032 6,151.45 72 228.944 4,171.08 80# 253.684 5,121.25 88# 278.424 6,168.84 73 229.337 4,185.40 80# 254.077 5,137.12 88# 278.817 6,186.25 73# 229.729 4,199.74 81 254.470 5,153.01 88# 279.210 6,203.69 73# 230.122 4,214.11 81# 254.862 5,168.93 89 279.602 6,221.15 73# 230.515 4,228.51 81# 255.255 5,184.87 89# 279.995 6,238.64 73; 230.908 4,242.93 81# 255.648 5,200.83 89# 280.388 6,256.15 73# 231.300 4,257.37 81# 256.040 5,216.82 89# 280.780 6,273.69 73# 231.693 4,271.84 81# 256.433 5,232.84 89# 281.173 6,291.25 73 i 232.086 4,286.33 81# 256.826 5,248.88 89| 281.566 6,308.84 74 232.478 4,300.85 81# 257.218 5,264.94 89# 281.959 6,326.45 74 L 232.871 4,315.39 82 257.611 5,281.03 89# 282.351 6,344.08 74; 233.264 4,329.96 82# 258.004 5,297.14 90 282.744 6,361.74 74# 233.656 4,344.55 82# 258.397 5,313.28 90# 283.137 6,379.42 74 234.049 4,359.17 82# 258.789 5,329.44 90# 283.529 6,397.13 74# 234.442 4,373.81 82# 259.182 5,345.63 90# 283.922 6,414.86 74# 234.835 4,388.47 82# 259.575 5,361.84 90# 284.315 6,432.62 74- i 235.227 4,403.16 82# 259.967 5,378.08 90# 284.707 6,450.40 75 235.620 4,417.87 82# 260.360 5,394.34 90# 285.100 6,468.21 • 75 i 236.013 4,432.61 83 250.753 5,410.62 90# 285.493 6,486.04 75# 236.405 4,447.38 83# 261.145 5,426.93 91 285.886 6,503.90 CIRCUMFERENCES AND AREAS OF CIRCLES. 565 Diam. Circum. Area. Diam. Circum. Area. Diam. Circum. Area. J 91* 91* 91* 91* 91* 91* 91* 92 92* 92* 92* 92* 92* 92* 92* 93 93* 93£ 93* 93* 93* 93* 93* 94 286.278 286.671 287.064 287.456 287.849 288.242 288.634 289.027 289.420 289.813 290.205 290.598 290.991 291.383 291.776 292.169 292.562 292.954 293.347 293.740 294.132 294.525 294.918 295.310 6.521.78 6.539.68 6,557.61 6.575.56 6.593.54 6.611.55 6.629.57 6,647.63 6,665.70 6,683.80 6,701.93 6,720.08 6,738.25 6,756.45 6.774.68 6.792.92 6,811.20 6,829.49 6,847.82 6,866.16 6,884.53 6.902.93 6,921.35 6.939.79 94* 94* 94* 94* 94* 94* 94* 95 95* 95* 95* 95* 95* 95* 95* 96 96* 96* 96* 96* 96* 96* 96* 97 295.703 296.096 296.488 296.881 297.274 297.667 298.059 298.452 298.845 299.237 299.630 300.023 300.415 300.808 301.201 301.594 301.986 302.379 302.772 303.164 303.557 303.950 304.342 304.735 6,958.26 6,976.76 6,995.28 7.013.82 7,032.39 7.050.98 7.069.59 7.088.24 7.106.90 7.125.59 7,144.31 7,163.04 7,181.81 7.200.60 7,219.41 7.238.25 7,257.11 7.275.99 7.294.91 7,313.84 7,332.80 7.351.79 7.370.79 7.389.83 97* 97* 97* 97* 97* 97* 97* 98 98* 98* 98* 98* 98* 98* 98* 99 99* 99* 99* 99* 99* • 99* 99* 100 305.128 305.521 305.913 306.306 306.699 307.091 307.484 307.877 308.270 308.662 309.055 309.448 309.840 310.233 310.626 311.018 311.411 311.804 312.196 312.589 312.982 313.375 313.767 314.160 7,408.89 7.427.97 7,447.08 7.466.21 7.485.37 7,504.55 7,523.75 7.542.98 7,562.24 7,581.52 7,600.82 7.620.15 7,639.50 7,658.88 7,678.28 7,697.71 7.717.16 7,736.63 7,756.13 7,775.66 7.795.21 7,814.78 7.834.38 7,854.00 The preceding table may be used to determine the diameter when the circumference or area is known. Thus, the diameter of a circle haying an area of 7,200 sq. in. is approximately 95* in. A GLOSSARY OF MINING TERMS. The present glossary is a combination of glossaries of mining terms con- tained in the following works: Coal and Metal Miners’ Pocketbook, Fifth Edition; Raymond’s Glossary of Mining and Metallurgical Terms; Powers Pocketbook for Miners and Metallurgists; Locke’s Miners ? Pocketbook; Vol AC, Second Pennsylvania Geological Survey; Ilhseng s Manual ot Mining; Chism’s Encyclopedia of Mexican Mining Law; a Glossary of Terms as Used in Coal Mining, by W. S. Gresley; 11th Annual Report of the State Mine Inspector of Missouri; Bullman’s Colliery Working and Management Reynolds’ Handbook of Mining Laws; Report of the Mine Inspector of Tennessee for 1897; Smithsonian Report for 1886; together with a large num- ber of words which have been added from various stray sources It is impossible to quote the authority for each definition, as many of the defini- tions are combinations from a number of authors. Where such different definitions have given distinctly different meanings each one has been included, but where there has been expressed merely a slight shade of difference, the definition agreeing most closely with current American practice has been taken, or else modified to suit such .practice. The foreign words selected are those with which an American is most likely, to come in contact, and this portion of the glossary is, of course, not exhaustive. For the large number of purely local terms used m the several coal fields of Great Britain, the reader is referred to Mr. Gresley’s glossary. 566 Aba GLOSSARY. Air GLOSSARY. Abattis (Leicester).— Cross-packing of branches or rough wood, used to keep roads open for ventilation. Abra (Spanish).— Fissure in a lode, unfilled or only partially filled. Abronziado ( Spanish ) .—Copper sulphides. Absolute Pressure— The pressure reckoned from a vacuum. Absolute Temperature.—' The temperature reckoned from the absolute zero, —459.2° F. or —273° C. Accompt (Cornish).— Settling day or place. Achicar (Mexican).— To diminish the quantity of water in any gallery or working, generally by carrying it out in buckets or in leather bags. Achicadores — Laborers employed for said purpose. Achichinques.— Same as Achicadores. Also applied to hangers-on about police courts, etc. Such people as are generally called strikers in the United States. Acreage Rent (English).— Royalty or rent for working minerals. Adarme (Mexican).— A weight for gold, about 1.8 grams. Addlings (North of England).— Earnings. Ademador ( Spanish) .—Mine carpenter, or timberman. Ademar (Spanish). — To timber. . Adit— A nearly horizontal passage from the surface, by which a mine is entered and unwatered with just sufficient slope to insure drainage. In the United States, an adit driven across the measures is usually called a tunnel, though the latter, strictly speaking, passes entirely through a hill, and is open at both ends. Adobe.— Sun-dried brick. Adventurers— Original prospectors. Adverse— To oppose the granting of a patent to mining claim. Adze. — A curved cutting instrument for dressing timber. Aerage (French).— Ventilation. Aerometers.— The air pistons of a Struve ventilator. Aerophore— The name given to an apparatus that will enable a man to enter places in mines filled with explosive or other deadly gases, with safety. Afinar (Mexican).— Refining gold and silver. Afterdamp— The gaseous mixture resulting from an explosion of firedamp. Agent— The manager of a mining property. Agitator— A mechanical stirrer used in pan amalgamation. Ahondar (Spanish).— To sink. Air —The current of atmospheric air circulating through and ventilating the workings of a mine. Air Box. — Wooden tubes used to convey air for ventilating headings or sinkings or other local ventilation. Air Compartment— An air-tight portion of any shaft, winze, rise, or level, used for improving ventilation. Air-Course— See Airway. Air Crossing— A bridge that carries one air-course over another. Air Cushion— A spring caused by confined air. Air Door.— A door for the regulation of currents of air through the workings of a mine. „ , . , . , Air-End Way (Locke).— Ventilation levels run parallel with mam level. Air Furnace. — A reverberatory furnace in which to smelt lead. Air Gates (Locke).— (l) Underground roadways, used principally for venti- lating purposes. (2) An air regulator. Air Head (Staff).— Ventilation ways. Air Heading— An airway. . Air Hole (Powers). — A hole drilled in advance to improve ventilation by communication with other workings or the surface. Airless End.— The extremity of a stall in longwall workings in which there is no current of air, or circulation of ventilation, but which is kept pure by diffusion and by the ingress and egress of cars, men, etc. AIR GLOSS AR Y. Aqu 567 Air Level— A. level or airway of former workings made use of in subsequent deeper mining operations for ventilating purposes. Air Oven —A heated chamber for drying samples of ore, etc. Air Five —A pipe made of canvas or metal, or a wooden box used in con- A veying air P to the workmen, or for rock drills or air locomotives. Air-Shaft.— A shaft or pit used expressly for ventilation. Air Slit (Yorks). — A short head between other air heads. . , Air Sollar .-A brattice carried beneath the tram rails or road bed in a head- Air ^Stnclf.—A Sack or chimney built over a shaft for ventilation. Airway— Any passage through which air is carried. Aitch Piece— Parts of a pump in which the valves are fixed. Albanil (Spanish).— Mason. AWerU^rnac^— ^continuous reverberatory for mercury ores. Alcam (Wales).— Tin. jllloy homogeneous mixture of two or more metals by fusion. Alluvial Gold— Gold found associated with water- worn material. Alluvium. — Gravel, sand, and mud deposited by streams. Almadeneta (Spanish).— Stamp head. AUern^m^^^nl—Y^^ down, or backward and forward motion. Alto ( Mexican) —The hanging wall of a vein. See Respaldos. Aludel (Spanish).— Earthen condenser for mercury Amalgam.- An alloy of quicksilver with some other metal. Amalgamation. — Absorption of gold and silver by mercury. Amalgamator.— One that amalgamates gold and silver ores. Ana^is?— The dttSminatio^of the original elements and the proportions Anemometer^— An instrument used for measuring the velocity of a ventilating An^Beam — A two-limbed beam used for turning angles in shafts, etc. heating and then cooling Anth^iU- Coal containing a small percentage of volatile matter Anticline.- A flexure or fold in which the rock s on the ° f Pff )sl {| t f fold dip awav from each other, like the two legs ot tne letter a. ±iie inclination on one side may be much greater than on n & e n ^ P wSh sides An anticlinal is said to be overturned when the rocks on both sides a saddle in a mineral vein, or the line along the summit of a vein, from which the vein dips in opposite directions. Anticlinal Flexure: Anticlinal Fold. — An anticline. < . . Antiauos Los (Mexican).— The Spanish or Indian miners of colonial times. Antimony Star.— The metal antimony when crystallized, showing fern-like that rewash or rework tailings from silver ^pcros^exican) 8 -^!' kinds^miningiupplies in general. Aperador.-A Apex™ Th e e eP linding point at the top of a slope or incHned plane the knuckle; also, the top of an anticlinal. In the U. S. Revised statutes, the end or edge of a vein nearest the surface. A pique (Mexican).— Perpendicular. Apolvillados (Spanish). — Superior ores. a «nir- Anrnn (English) — (1) A covering of timber, stone, or metal, .to protect a sur ^ Pr ?ace a^ainst the actionof water flowing’over it. (2) A hinged extension to a loading chute. Aprons . — Stamp-battery copper plates. Aqua Fortis. — Nitric acid. * . _ .. . . . Aqua Regia— A mixture of hydrochloric acid and nitric acid. Aqueduct— An artificial elevated way for carrying water. 568 Ara GLOSSARY. AZO Arajo (Mexican).— See Hatajo. Arch (Cornish).— Portion of lode left standing to support hanging wall, or because too poor. Archean.— An early period of geological time. Arching— Brickwork or stonework forming the roof of any underground roadway. Arenaceous. — Sandy; rocks are arenaceous when they contain a considerable percentage of sand. Arends Tap— An inverted siphon for drawing molten lead from a crucible or furnace. ) Arenillas (Spanish). — Refuse earth. Argentiferous. — Silver-bearing. Argillaceous. — Clayey; rocks are argillaceous when they contain a consid- erable percentage of clay, or have some of the characteristics of clay. Argol. — Crude tartar deposited from wine. Arian (Wales).— Silver. Arm. — The inclined leg of a set of timber. Arrage (North England).— Sharp corner. Arrastre. — A circular trough in which drags are pulled round by being con- nected with a central revolving shaft by an arm and chain. Used for grinding and amalgamating ores. Arrastre de cuchara , spoon arrastre; de marca, large arrastre; de mula, mule-power arrastre. Arvastrar (Mexican).— To drag along the ground. Arrastrar el Agua.— To almost completely exhaust the water in a sump or working. Arroba (Mexican). — 25 lb. Artesian Well. — An artificial channel of escape, made by a bore hole, for a subterranean stream, subject to hydrostatic pressure. Ascensional Ventilation. — The arrangement of the ventilating currents in such a manner that the air shall continuously rise until reaching the bottom of the upcast shaft. Particularly applicable to steep seams. Ashlar.— A facing of cut stone applied to a backing of rubble or rough masonry or brickwork. Aspirail (French).— Opening for ventilation. Assay.— The determination of the quality and quantity of any particular substance in a mineral. Assayer. — One who performs assays. Assessment Work. — The annual work necessary to hold a mining claim. Astel. — Overhead boarding in a gallery. Astyllen (Cornish).— Small dam in an adit; partition between ore and deads on grass. .itacador (Mexican).— A tamping bar or tamping stick. Atecas (Mexican).— Same as Achicadores , etc. Atierres (Spanish).— Refuse rock or dirt inside a mine. Attle (Cornish). — Refuse rock. Attle {Addle). — The waste of a mine. Attrition. — The act of wearing away by friction. Auger Stem.— The iron rod or bar to which the bit is attached in rope drilling. Auget. — Priming tube. Aur (Wales).— Gold. Auriferous. — Gold-bearing. Ausscharen (German).— Junction of lodes. Auszimmern ( German) . — Timbering. Average Produce (Cornish). — Percentage of fine copper in ore. Average Standard (Cornish). — Price of pure copper in ore. Aviador (Spanish). — One who provides the capital to work a mine. Avio. — Money furnished to the proprietors of a mine to work the mine, by another person, the Aviador. Avio Contract. — A contract between two parties for working a mine by which one of the parties, the aviador , furnishes the money to the proprietors for working the mine. Axis. — An imaginary line passing through a body that may be supposed to revolve around it. Azimuth— The azimuth of a body is that arc of the horizon that is included between the meridian circle at the given place and a vertical plane passing through the body. It is always measured from due north around to the right. Azogue (Spanish). — Mercury. Azogueria. — Amalgamating works. Azoguero. Amalgamator. The person in charge of a patio works. Azogues— Free milling ores. Azoic.— The age of rocks that were formed before animal life existed. Bac GLOSSARY. Ban 569 Back. — (1) A plane or cleavage in coal, etc., having frequently a smooth parting and some sooty coal included in it. (2) The inner end of a heading or gangway. (3) To throw back into the gob or waste the small slack, dirt, etc. g (4) To roll large coals out of a waste for loading into cars. Back Balance.— A self-acting incline m the mnie^wherea glance caranda carriage in which the mine car is placed are used. The lo aded car upo A . the carriage will hoist the balance car, and the balance car will hoist the Backbye^WorL— Wor^done between the shaft and the working face, in contradistinction to face work, or work done at the face. . f Back Casing.— A wall or lining of dry bricks used m ®^ 1 ?f t thr ^f h Q £ 1 deposits, the permanent walling being built up within it. The use oi timber cribs and planking serves the same purpose. Back End (England). -The last portion of a jud. Backina.—( 1) The rough masonry of a wall faced with finer work. (2) Eartn deposited behind a retaining wall, etc. (3) Timbers let into notches m the rock across the top of a level. , . , - Plirh „ fnr Backing Deals— Deal boards or planking placed at the back of curbs tor supporting the sides of a shaft that is liable to run. Back Joint. — Joint plane more or less parallel to the strike of the cleavage, BaddasA— {!) Backward suction of air-currents produced after an explosion of firedamp. (2) Reentry of air into a fan. , . Back of Ore.— The ore between two levels which has to be worked from the Back Pressured— The loss, expressed in pounds per square inch, due to getting the steam out of the cylinder after it has done its work. Back Shift— Afternoon shift. , . . . Back Skin (North of England). -A leather jacket for wet workings. Backstay.— A wrought-iron forked bar attached to the back of pars when ascending an inclined plane, which throws them off the rails if the rope BaffEnds^— Long wooden edges for adjusting linings in sinking shafts dur- ing the operation of fixing the lining. Baffle— To brush out firedamp. Bait.— Provisions. _ , _ Bajo (Mexican).— The footwall of a vein. See Respaldo. B alance.— 0*) The counterpoise or weights attached to the engine, to assist the engine m lifting the load out of a shaft bottom and in helping it to slacken speed when the cage reaches the surface, it consists often of a bunch of heavy chains suspended in a shallow shaft, the chains resting on the shaft bottom as unwound off the balance drum attached to the main shaft of the engine. (2) Scales used in chemical , Balance ^Bob .^A farge beam or lever attached to the main rods of a Cornisb pumping engine, carrying on its outer end a counterpoise. Balance Box.— A large box placed on one end of a balance bob and fillea with old iron, rock, etc. to counterbalance the weight of pump rods Balance Brow.— An inclined plane in steep seams on which a platform on wheels travels and carries the cars of coal. Balance Car.— A small weighted truck mounted upon a short inchnM track, and carrying a sheave around which the rope of an endless haulage system passes as it winds off the drum. Balance Pit.— A pit or shaft in which a balance rises or falls. Balanzon (Mexican). -The balance bob of a Cornish pump Balk _(i) a more or less sudden thinning out of a seam of coal. (2) irregu- lar-shaped masses of stone intruding into a coal seam, or bulgings out of the stone roof into the seam. (3) A bar of timber supporting the roof of a mine, or for carrying any heavy load. Balland (Derbyshire). — Pulverulent lead ore. . , D Ballast.— Broken stone, gravel, sand, etc. used for keeping railroad ties stead, . Bancos (Spanish) .—Horses in a vein or cross-courses. # Band.— A seam or thin stratum of stone or other refuse in a seam of coal. Bank.—( 1) The top of the shaft, or out of the shaft. (2) The surface around the mouth of a shaft. (3) To manipulate coals, etc. on the bant. (4) The whole or sometimes only one side or one end of a worxm & place underground. (5) A large heap of mineral on the surface. 570 Ban GLOSSARY. Bas Bank Chain— A chain that includes the bank of a river or creek. Bank Claim (Australian).— Mining right on bank of stream. Banket. — Auriferous conglomerate of South Africa. Bank Head. — The upper end of an inclined plane, next to the engine or drum, made nearly level. Bank Right (Australian). — Right to divert water to bank claim. Banksman.— The man in attendance at the top of the shaft, superintending the work of banking. Bankwork.—A system of working coal in South Yorkshire. Bank to Bank. — A shift. Bannocking. — See Kirving. Bano (Spanish).— Excess of mercury used in torta. Bar— A length of timber placed horizontally for supporting the roof. In some cases, bars of wrought iron, about 3 in. X 1 in. X 5 ft. are used. Bar Diggings. — (1) River placers subject to overflow. (2) Auriferous claims on shallow streams. Bargain.— Portion of mine worked by a gang on contract. Barilla (Spanish).— Grains of native copper disseminated through ores. Baring.— See Stripping. Barmaster (Derbyshire) — Mine manager, agent, and engineer. Bar Mining.— The mining of river bars, usually between low and high water, although the stream is sometimes deflected and the bar worked below water level. Barney.— A small car, used on inclined planes and slopes to push the mine car up the slope. Barney Pit.— A pit at the bottom of a slope or plane into which the barney runs to allow the mine car to pass over it. Barra (Mexican).— (1) A bar, as of gold, silver, iron, steel, etc. (2) A cer- tain share in a mine. The ancient Spanish laws, from time immemorial, considered a mine as divided into 24 parts, and each part was called a “ barra.” Barra Viuda, or Aviada (Mexican).— These are “ barras ” or shares that par- ticipate in the profits, but not in the expenses, of mining concerns. Their share of the expenses is paid by the other shares. Non-assessable shares. Barranca (Mexican).— A ravine, a gulch. What is improperly called in the United States a canyon or canon. Barrel Amalgamation. — Amalgamating ores in revolving barrels. Barrel Work. — (1) Native copper that can be hand-sorted ready for smelt- ing. (2) Barrel amalgamation. Barrena (Mexican).— A hand drill for opening holes in rocks for blasting purposes. Barrenarse (Mexican).— When two mines or two workings (as a shaft or winze, or a gallery) communicate with each other. Barren Ground— Strata unproductive of seams of coal, etc. of a workable thickness. Barreno (Mexican) .—(1) A drill hole for blasting purposes. In mechanics, any bored hole. (21 A communication between two mines or two workings. Barretero (Mexican).— A miner of the first class; one that knows how to point his holes, drill, and blast, or work with a gad. Barrier Pillar— A solid block or rib of coal, etc., left unworked between two collieries or mines for security against accidents arising from influx of water. Barrier System. — The method of working a colliery by pillar and stall, where solid ribs or barriers of coal are left in between a set or series of working places. Barrow— (1) A box with two handles at one end and a wheel at the other. (2) Heap of waste stuff raised from a mine; a dump. Bar Timbering. — A system of supporting a tunnel roof by long top bars, while the whole lower tunnel core is taken out, leaving an open space for the masons to run up the arching. Under certain conditions, the bars are withdrawn after the masonry is completed, otherwise they are bricked in and not drawn. Base Bullion. — Lead combined with precious metals. Base Metal.— Metal not classed with the precious metals, gold, silver, plat- inum, etc., that are not easily oxidized. Basin. — (1) A coal field having some resemblance in form to a basin. (2) The synclinal axis of a seam of coal or stratum of rock Basket.— A measure of weight = 2 cwt. Bas GLOSSARY. Ben 571 Basque.— Crucible or furnace lining. Bass (Derbyshire).— Indurated clay. Basset— Outcrop of a lode or stratum. Rastard A particularly hard massive rock or boulder. Batch.— An assorted parcel of ore, sometimes called doles, when divided into equal quantities. , , rtnfpn A shallow wooden bowl used for washing out gold, etc. Batt (English).— (1) A highly bituminous shale found in the coal measures. (2) Hardened clay, but not fireclay. Same as Bend and Bind. Ratten A niece of thin board less than 12 in. m width. . Batter. — The inclination of a face of masonry or of any inclined portion of BaUeriL—O - )° ^structure built to keep coal from sliding down a chute or breast. (2) An embankment or platform on which miners work. (3) i^a^An^pen^pace for waste between two packs in a longwall working. I «£• ° r p h iati rT- Beans (Nortl? of England) .—All coal that will pass through about 9 screen Bean Shot.— Copper granulated by pouring into hot water. jipar A denosit of iron at the bottom of a furnace. ^ . , , , Bear; to Bear In— Underholding or undermining; driving m at the top or at Be Jern -Pieces of’ttaber 3 or 4 ft. longer than the breadth of a shaft, which are fixed into the solid rock at the sides at certain intervals apart, B eaZg-d The span or length in the clear between the points of support of a beam, etc. (3) The points of support Bernina JoT-AdoOT placid for the purpose of directing and regulating the amount If ventilation passing through an entire district of a mine. Bearing In.— The depth or distance under of the undercut or holing. BmHng-up Pulley.-k pulley wheel fixed in a frame and arranged to tighten ud or take up the slack rope in endless-rope haulage. . Bearmg-up Stop.— A partition of brattice or plank that serves to conduct air to a face. means of wedges and sledge hammers Bed — (i) The level surface of a rock upon which a curb or crib is laid. (2) A Bed^^^S^Austraii^)!— Ilciaim^th^includes the bed of a river or creek. Bednlate —A large plate of iron used as a foundation for an engine. Bed-Rock. — The f olid rock underlying the soil, drift, or alluvial deposits. o f “ the form, disconnected from the 5eid^-A°form of lead poisoning to which lead miners are subject. rpJIv — a swelling mass of ore in a lode. „ , . _ Ben,' Benhayl (Cornish).— Productive. The productive portion of Bench^—i 1) A natural terrace marking the outcrop of any stratum. stratum of coal forming a portion of the vein. Bench Diaaings.— River placers not subject to overnow. , ,. . Benching'.— Yo break up with wedges the bottom coals when the holing is done in the middle of the seam. * , Benching Up (North of England). -Working on top of coal. Bench Mark.— A mark cut in a tree or rock whose elevation is known. Used bv surveyors for reference in determining elevations. , ■» . Bench Working.— 1 The system of working one or more seams or beds ot mineral bv open working or stripping, m stages or steps. Bend (Derbyshire).— Indurated clay. _ + i, 0 Beneficiar (Mexican).— To treat ores for the purpose of extracting the metallic contents. a tin (2) A 572 Ben GLOSSARY. Blo Beneficio (Mexican).— Any metallurgical process. Benheyl (Cornish).— Flowing tin stream. Bessemer Steel— Steel made by the Bessemer process. Beton (English).— Concrete of hydraulic cement with broken stone, bricks, gravel, etc. Bevel.— The slope formed by trimming away on edge. Bevel Gear.— A gear-wheel whose teeth are inclined to the axis of the wheel. Biche — A hollow-ended tool for recovering boring rods. Billy Boy. — A boy who attends a Billy Playfair. Billy Playfair.— A mechanical contrivance for weighing coal, consisting of an iron trough with a sort of hopper bottom, into which all the small coal passing through the screen is conducted and weighed off and emptied from time to time. Bin.— A box with cover, used for tools, stones, ore, etc. Bind, or Binder— Indurated argillaceous shales or clay, very commonly forming the roof of a coal seam and frequently containing clay iron- stone. See Batt. Binding.— Hiring men. Bing (North of England).— 8 cwt. of ore. Bing Hole (Derbyshire). — An ore shoot. Bing Ore (Derbyshire).— Lead ore in lumps. Bing Tale (North of England).— Ore given to the miner for his labor. Bit— A piece of steel placed in the cutting edge of a drill or point of a pick. Blackband — Carbonaceous ironstone in beds, mingled with coaly matter sufficient for its own calcination. Black Batt, or Black Stone— Black carbonaceous shale. Black Copper. — Impure smelted copper. Blackdamp.— Carbonic-acid gas. Black Diamonds. — Coal. Black Ends.— Refuse coke. Black Flux. — Charcoal and potassium carbonate. Black Jack.—( 1) Properly speaking, dark varieties of zinc blende, but many miners apply it to any black mineral. (2) Crude black oil used to oil mine cars. Black Lead— Graphite. Black Ore (English).— Partly decomposed pyrites containing copper. Black Sand. — Dark minerals found with alluvial gold. Black Stone.— A carbonaceous shale. Black Tin.— Dressed cassiterite; oxide of tin. Blanch.— (1) A piece of ore found isolated in the hard rock. (2) Lead ore mixed with other minerals. Blanched Copper.— Copper alloyed with arsenic. Blanket Stroke (Australian).— Sloping tables or sluices lined with baize, for catching gold. , , , Blanket Tables.— Inclined planes covered with blankets, to catch the heavier minerals passing over them. / Blast— (1) The sudden rush of fire, gas, and dust of an explosion through the workings and roadways of a mine. (2) To cut or bring down coal, rocks, etc. by the explosion of gunpowder, dynamite, etc. Blasting Barrel— A small pipe used for blasting in wet or gaseous places. Blast Pipe— A pipe for supplying air to furnaces. Blende— Sulphide of zinc; sphalerite. Bliclz (Germany).— Iridescence on gold and silver at end of cupeling. Blind Coal— Coal altered by the heat of a trap dike. Blind Creek.— { 1) A creek in which water flows only in very wet weather. (2) (Australasian) Dry watercourse. Blind Drift.— A horizontal passage in the mine not yet connected with the other workings. Blind Joint.— Obscure bedding plane. Blind Lead, or Blind Lode.— A vein having no visible outcrop. Blind Level. — (1) An incomplete level. (2) A drainage level. Blind Shaft, or Blind Pit— A shaft not coming to the surface. Bloat— A hammer swelled at the eye. Block Claim (Australian).— A square mining claim. Block Coal— Coal that breaks in large rectangular lumps. Blocking 0ut.—(l) Working deep leads in blocks; somewhat like horizontal stoping. (2) (Australian! Washing gold gravel in sections. Block Reefs— Reefs showing frequent contractions longitudinally. Blo GLOSSARY. Bon 573 Block Tin. — Cast tin. J iWn, or any indicating traces of a coal bed or mineral deposit. Blossom Rock.— (1) Colored veln?tone a detached from an outcrop. (2) The rock detached from a vein but which has not been transported. Blow. — (1) * To blast with gunpowder, etc. (2) A dam or stopping is said to blow when gas escapes through it. . . /r) >. A Blower — (1) A sudden emission or outburst of gas m a mine. (2) Any emission of gas from a coal seam similar to that from an ordinary gas burner. (3) A 'type of centrifugal fan used largely to force air into furnaces (4) A blowdown ventilating fan. . , Blow Fan.— A. small centrifugal fan used to force air through canvas pipes or wooden boxes to the workmen. Blowdown Fan.— A force fan. Blow In . — To commence a smelting process. . Blown- Out Shot— A shot that has blown out the tamping, but not broken the coal or rock. „ x _ ... Blow Off — To let off excess of steam from a boiler. . Blow Out — (1) To finish a smelting campaign. (2) A blown-out shot. (3) The decomposed mineral exposure of a vein. . „ o Blowpipe— An instrument for creating a blast whereby the heat of a flame or lamp can be better utilized. Blue Billv. — Residue of copper pyrites after roasting with salt. Blue Cap!— 1 The blue halo of ignited gas (firedamp and air) on the top of the flame in a safety lamp, in an explosive mixture. Blue Elvan (Cornish).— Greenstone. Blue J JLeak —A blue^Sained stratum of gravel of great extent and richness. Blue Metal.— A local term for shale possessing a bluish color. Blue Peach (Cornish). — A slate-blue fine-grained schorl. Milestone —(1) Sulphate of copper. (2) Lapis lazuli. (S) Basalt. (4) Maryland, 3 a gray gneiss; in Ohio, a gray sandstone; in the District of Columbia, a mica schist; in New York, a blue-gray sandstone; in Pennsylvania, a blue-gray sandstone. (5) A popular term among stone men not suf- ficiently definite to be of value. 'Board.— A wide heading usually from 3 to 5 yd. wide. Board-and-Pillar .— A system of working coal where the first stage of exca- vation is accomplished with the roof sustained by pillars of coal left between the breasts; often called Breast-and-Pillar. Bob —An oscillating bell-crank, or lever, tnrough which the motion of an engine is transmitted to the pump rods in an engine or pumping pit. There are x bobs, L bobs, and V bobs. . , Boca or Boca Mina (Mexican).— Mouth or mine mouth. This is the name applied to the principal or first opening of a mine, or to the one where the miners are accustomed to descend. ... Bochorno (Mexican).— Excessive heat, with want of ventilation, so that the Bodm—\lf°A^ ore body, or pocket of mineral deposit. (2) The thickness of a lubricating oil or other liquid; also the measure of that thickness exnressed in the number of seconds in which a given quantity of the oil at a given temperature flows through a given aperture. Bog Iron Ore.— Loose earthy brown hematite recently formed in swampy Boleo (Mexican) .—A dump pile for waste rock. Boliche (Spanish.).— Concentrating bowl. Bollos (Spanish).— Triangular blocks of amalgam. Bolsa (Spanish).— Small bunch of ore.. Bonanza. — An aggregation of rich ore m a mine. , , » « Bond.—{ 1) The arrangement of blocks of stone or brickwork to form a firm structure by a judicious overlapping of each other so as to break joint. (2) An agreement for hiring men. Bone.— Slatv coal or carbonaceous shale found m coal seams. Bone Ash —Burnt bones pulverized and sifted. „ . Bonnet— (1) The overhead cover of a cage. .(2) A cover for the gauze of a safety lamp. (3) A cap piece for an upright timber. Bonney (Cornish) .—An isolated body of ore. 574 Bon GLOSSARY. Bre Bonze. — U ndressed lead ore. Booming.— Ground sluicing on a large scale by emptying the contents of a reservoir at once on material collected below, thus removing boulders. Bord (English).— A narrow breast. Bord-and-Pillar (English).— See Pillar-and- Breast. Bord Room. — The space excavated in driving a bord. The term is used in connection with the “ridding” of the fallen stone in old bords when driving roads across them in pillar working; thus, “ ridding across the old bord room.” Bord Ways Course.— The direction at right angles to the mam cleavage planes. In some mining districts, it is termed “on face.” Bore.— To drill. Bore Hole. — A hole made with a drill, auger, or other tools, m coal, rock, or other material. Borrasca (Mexican). — The reverse of bonanza. When the mine has a vein, but no ore, it is said to be “ en borrasca.” Bort.— Amorphous dark diamond. Bosh.— The plane in a blast furnace where the greatest diameter is reached. Boss (English).— (1) An increase of the diameter at any part of the shaft. (2) A person in charge of a piece of work. Botas (Mexican). — Buckets made of an entire ox skin, to take out water. Botryoidal.— Grape-like in appearance. Bottle Jack (English).— An appliance for lifting heavy weights. Bottom.— (1) The landing at the bottom of the shaft or slope. (2) The lowest point of mining operations. (3) The floor, bottom rock, or stratum underlying a coal bed. (4) In alluvial, the bed rock or reef. Bottomer, Bottomman. — The person that loads the cages at the pit bottom and gives the signal to bank. Bottom Joint.— Joint or bedding plane, horizontal or nearly so. Bottom Lift.—( 1) The deepest column of a pump. (2) The lowest or deepest lift or level of a mine. Bottom Pillars.— Large pillars left around the bottom of a shaft. Bottoms. — Impure copper alloy below the matte in smelting. Boulders. — Loose rounded masses of stone detached from the parent rock. Bounds (Cornish).— A tract of tin ground. Bout (Derbyshire).— Twenty-four dishes of lead ore. .Bow.— The handle of a kibble. „ , _ , Bowk. — An iron barrel or tub used for hoisting rock and other debris when sinking a shaft. , , , Bowke (Staffordshire).— A small wooden box for hauling ironstone under- ground. Bowl Metal.— The impure antimony obtained from doubling. Bowse (Derbyshire).— Lead ore as cut from the lode. Box.— (1) A 12' to 14' section of a sluice. (2) A mine car. Box Bill.— Tool for recovering boring rods. Boxing.— A. method of securing shafts solely by slabs and w<3oden pegs. Brace. — (1) An inclined beam, bar, or strut for sustaining compression or tension. See Tie-Brace , Sway-Brace. (2) A platform at the top of a shaft on which miners stand to work the tackle. (3) (Cornish) Building at pit mouth. . _ , , . ,, , Brace Heads— Wooden handles or bars for raising and rotating the rods when boring a deep hole. Braize .— Charcoal dust. Brake Seive— Hand jigger. Brances .— Iron pyrites in coal. Branch .— Small vein shooting off from main lode. Brashy— Short and tender. _ . - , .. Brasque . — A mixture of clay and coke or charcoal used for furnace bottoms. Brass. — (1) Iron pyrites in coal. (2) An alloy of copper and zinc. Brasses (English).— Fitting of brass in plummer blocks, etc., for diminishing the friction of revolving journals that rest upon them. Brat.— A thin bed of coal mixed with pyrites or limestone. Brattice— A lining or partition. . , . Brattice Cloth .— Ducking or canvas used for making a brattice. Brazzil (North of England). — Iron pyrites in coal. _ . , , „ Breaker . — In anthracite mining, the structure in which the coal is broken, sized, and cleaned for market. Known also as Coal Breaker. Breaker Bov.— A boy who works in a coal breaker. Bre GLOSSARY. BUL 575 Breakstaff.— The lever for blowing a Dlacksmiths’ bellows, or for working Breakthrough^- A^arrow passage cut factor Breas t— ( l) A stall, board, or room m which coal is mined. (2) I he lace or wall of a auarrv is sometimes called by this name. Breastand-Pttlar.—A system of working coal by boards or rooms with pillars Breattinfor f-The orlTaken from the face or end of the tunnel. breast Wall (English) —A wall built to prevent the falling of a \ertical face Brecc?a.— A rock^omposed of angular fragments cemented together. Breeding Fire. — See Gob L?ire. Breese.— Fine slack. _ , . Breeze— Small coke, probably same as braize or braise. Brettis fDerbvshire) .— A timber crib filled with slacR. . Bridge.— {1) A platform on wheels running on rails for covering of a shaft or slope. (2) A track or platform passing over an inclined haulage way and which can be raised out of the way of ascending and BridtecTcdnt— Short chains by which a cage, . car, or attached to a winding rope; of use in case the rope pulls out of socket. Briquets. — Fuel made of slack or culm and pressed ^otaick mr ti a llv Broaching Bit— A tool for reopening a bore hole that has been partially closed by swelling of the walls. Brob.—A spike to prevent timber slipping. Broil (Cornish). — Traces of a vein in loose matter. ir, nrmtrfl- Ttmken A district of coal pillars m process of removal, so called m contra distinction^ to the tot working of a seam by bord-and-wall, or working in the “whole.” See Whole Working. Q1 . Broken Coal.— Anthracite coal that will pass through a mesh or bars 3 4 to 44- in. , and over a mesh 2f in. square. ( See page 434. ) Bronce (Mexican).— In mining, copper or iron pyrites. Brooch (Cornish).— Mixed ores. Broochinq. — Smoothing. Brood (Cornish).— Heavy waste from tin and copper ores. pithpr Brow.— An underground roadway leading to a working place driven either Brown^Coal— Lignite. 6 A fuel classed between peat and bituminous coal. Brown Spar.— Dolomite containing carbonate of iron. Brownstone.-iff) Decomposed iron pyrites. (2) Brown ^sandstone. Browse . — Imperfectly smelted ore mixed with cinder and clay. Brujula (Mexican).— A surveyors’ (or marine) magnetic 1 ^P^s. Brush. — (1) To mix air with the gas m a mine working swinging a iacket etc. which creates a current. (2) To brush the roof oi an airway, is to take down some of the roof slate, to increase the height or headroom. . . , Brule (Cornish). — Traces of a vein in loose matter. Bucket.— (1) An iron or wooden receptacle for hoisting ore, or for raising rock in shaft sinking. (2) The top valve or clack of a pump. Bucket Pump— A lifting pump, consisting of buckets fastened to an endless Bii^etVword^—A wrought-iron rod to which the P um P^ c ^i\^ t e ached * Bucket Tree —The pipe between the working barrel and the wind bore. Bucking. — Breaking down ore with a very broad banmeii * : brelkfng Bucking Hammer.— An iron disk, provided with a handle, used tor breaking up minerals by hand. Buck Quartz. — Hard non-auriferous quartz. o . Buck Staff.— Uprights for bracing reverberatory furnaces together . Buckwheat- Anthracite coal that will pass through a mesh * in. and over a Buddie^- Aifinclined table, circular or oblong, on which ore is concentrated. Buddling.— Washing. Buggy.— A small mine car. „ ■ ... . , Bug Hole.— A small cavity usually lined with crystals. f Building.— A built-up block or pillar of stone or coal to support the roof. Buitron (Spanish). — A silver furnace of peculiar form. Bulkhead.— (1) A tight partition or stopping. (2) The end of a flume carry ing water for hydraulicking. 576 Bul GLOSSARY. Cal Bulldog.— A. refractory furnace lining of calcined mill cinder, containing iron and silica. Bull Engine.— A single, direct-acting pumping engine, the pump rods form- ing a continuation of the piston rod. Buller Shot.— A second shot put in close to, and to do the work not done by, a blown-out shot, loose powder being used. Bud.— An iron rod used in ramming clay to line a shot hole. Bulling. — Lining a shot hole with clay. Bullion.— Uncoined gold and silver. Bull Pump. — A single-acting pumping engine in which the steam cylinder is placed over the shaft or slope and the pump rods are attached directly to the piston rod. The steam enters below the piston and raises the pump rods; the water is pumped on the down stroke by the weight of the rode. Bull Pup.— A worthless claim. Bull Wheel. — A wheel on which the rope carrying the boring rod is coiled when boring by steam machinery. Bully. — A miners’ hammer. Bumping Table. — A concentrating table with a jolting motion. Bunch.— A small rich deposit of ore. Bunding— A staging in a level for carrying debris. Bunkers— Steam coal consumed on board ship. Bunney.—A nest of ore not lying in a regular vein. Buntons. — Timbers placed horizontally across a shaft or slope to carry the cage guides, pump rods, column pipe, etc.; also, to strengthen the shaft timbering. Burden. — (1) Earth overlying a bed of useful mineral. (2) The proportion of ore and flux to fuel in the charge of a blast furnace. Burr. — Solid rock. Burrow. — Refuse heap. Buscones (Spanish).— Prospectors, fossickers, tribute workers. Bush.— To line a circular hole with a ring of metal, to prevent the hole from wearing out. Butt— (1) Coal surface exposed at right angles to the face; the “ends” of the coal. (2) The butt of a slate quarry is where the overlying rock comes in contact with an inclined stratum of slate rock. Butt Entry.— A gallery driven at right angles with the butt joint (see page 285). Butterfly Valve.— A circular valve that revolves on an axis passing through its center. Butt Heading. — See Butt Entry. Button.— The globule of metal, the result of an assay. Button Balance.— A small very delicate balance used for weighing assay buttons. Butty'— A partner in a contract for driving or mining; a comrade, crony. Sometimes called “ Buddy.” By Level . — A side level driven for some unusual but necessary purpose. Cab. — The side parts of a lode, nearest the walls, which are generally hard and deficient of ore. Caballo (Mexican).— A “ horse ” or mass of barren rock in a vein. Cabezuela (Spanish).— Rich gold and silver concentrates.. Cabin . — (1) A miner’s house. (2) A small room in the mine for the use of the officials. Cable Drilling . — Rope drilling. Cage . — A platform on which mine cars are raised to the surface. Cage Guides.— Vertical rods of pine, iron, or steel, or wire rope, fixed in a shaft, between which cages run, and whereby they are prevented from striking one another, or against any portion of the shaft. Cager . — The person that puts the cars on the cage at the bottom of the shaft. Cage Seat . — Scaffolding, sometimes fitted v/ith strong springs, to take off the shock, and on which the cage drops when reaching the pit bottom. Cage Sheets . — Short props or catches on which cages stand during caging or changing cars. Caking Coal— Coal that agglomerates on the grate. Cal— Wolfram. Cala (Spanish).— Prospecting pit. Calcareous . — Containing lime. # . Calcine . — To heat a substance; not sufficiently to melt it, but enough to drive off the volatile contents. Cal GLOSSARY. Cau 577 Calcining Furnace— A furnace used for roasting ore in order to drive off certain impurities. Wmnta^mp^-Itndevnmp made of a wooden box t h / ou ,fh which an endless belfwith floats circulates; used for pumping water from shallow CaKra°(€ornish). — Stratified rocks traversed by lodes. . . t Cam.—( 1) A curved arm attached to a revolving shaft for raising stamps. (2) Carbonate of lime and fluorspar, found on the joints of lodes Camino (Mexican).— Any gallery, winze, or shaft, inside of a mine used tor general transit. „ . n . Woct Campaign.— The length of time a furnace remains m blast. ' required to .be ^removed l to make sloping sides and very narrow bottom. Cancha (Spanish).— Space for drying slimes. Cand ( Cornish ) —Fluorspar. Cank (Derbyshire).— Whinstone. . Canker . — The ocherous sediment m coal-pit waters. a mine - " Cante^Enghsh)!— Tlm'pieces^ornnng the ends of ^ckete of a waterwheel. Capdlma{ Mexican).— An old-style retort for retorting silver amalgam. Caple (Cornish).— Hard rock lining tin lodes. worked by horizontal arms or bars. . ~ Captain. — Cornish name for manager or boss of a mine. o. aT1 o-x VflVS Q r Car.— Any car used for the conveyance of coal along the gangways or haulage roads of a mine. Carat.— A weight nearly equal to 4 grains. . . thp comno- Carbon.— A combustible elementary substance forming the largest compo carh^-m Arichbunch of ore in the country rock connected with the lodeby a mere thr" ad of mineral. (2) (Cornish) An irregullr deposit of tin ore. . . . , Carbonaceous.— Coaly, containing carbon or coal. Carbonate.— Carbonic acid combined with a base. , f i d . Carbonates . — Lead ore. The oxide and carbonic-acid compounds ot lead, also applied to lead sulphate. generally of 300 pounds, but variable in different parts of Mexico. case filled with gunpowder, forming the charge for blasting. Cascajo (Mexican).— Gravel. Case— A fissure admitting water into a mine. . . steel bv Case-Harden— To convert the outer surface of wrought iron into steei Dy Tubing 1 in serf ed h? a? ^^"keep out water or to protect the Casfn^n™. Sg^iro^thal contains carbon (up to 5$), silicon, sulphur, phos- Cata (Spanish ).— A mine denounced but not worked. Catches— {1) Iron levers or props at the top and bottom of a shaft. ( ) P fitted on a cage to prevent cars from running ofl. Catch Pit— A reservoir for saving tailings from reduction works. Cauf (North of England).— A coal bucket or basket. , trunks of sieil- Cauldron Bottoms.- The fossil remains or the casts of the trunks ot s g laria that have remained vertical above or belowtheseam. Caulk.— To fill seams or joints with something to prevent leaking. GLOSSARY. Cho \78 Cau Cannier , or Cannier Lode (Cornish).— A vein running obliquely across the regular veins of the district. Cave , or Cave In— A caving-in of the roof strata of a mine, sometimes extend- ing to the surface. Cavils— Lots drawn by the hewers each quarter year to determine their working places. Cawk — Baryta sulphate. Cazeador (Spanish) . — Amalgamator. Cazo (Mexican).— A vessel for hot amalgamation. Any large copper or iron vessel. Cebar (Mexican).— (1) To melt rich ores, or lead bullion, etc. in a smelting furnace. (2) To add small quantities of material, from time to time, to the melted mass within a furnace. (3) Generally, to feed any kind or metallurgical machinery or process. Cement— (1) Auriferous gravel consolidated together. (2) A finely divided metal obtained by precipitation. (3) A binding material. Cementation— The process of converting wrought iron into steel by heating it in contact with charcoal, or of treating cast iron in a bed of hema- tite ore. Cendrada (Mexican).— The cupel bottom of a furnace. CendradUla (Mexican).— A small reverberatory furnace for smelting rich silver ores in a rough way. Also called Galeme. Center —A temporary support, serving at the same time as a guide to the masons, placed under an arch during the progress of its construction. Centrifugal Force.— A force drawing away from the center. Centripetal Force.— A force drawing toward the center. CH a — Marsh gas (see page 348). Chain.— A measure 66 or 100 ft. long, divided into 100 links. Chain-Brow Way— An underground inclined plane worked on the endless- chain svstem of haulage. Chain Pillar.— A pillar left to protect the gangway and air-course, and run- ning parallel to these passages. Chain Road— An underground wagomvay worked on the endless-chain system of haulage. Chair. — Sometimes applied to keeps. Chamber. — See Breast. Charco (Mexican).— A pool of water. Charge. — (1) The amount of powder or other explosive used in one blast or shot. (2) The amount of flux used in assaying. (3) The material fed into a furnace at one time. Charqnear (Mexican).— To dip out water from pools within the mine, throwing it into gutters or pipes that will conduct it to the shaft. Chats— (1) The gravel-like tailings derived from the concentration of ores. (2) A low-grade ore, often too poor to handle; the refuse from concen- tration works. (3) (North of England) Small pieces of stone with ore. Check- Battei'y— A battery to close the lower part of a chute, acting as a check to the flow of coal and as an air stopping. Checker Coal— Anthracite coal that seems to be made up of rectangular grains. Check- Weighman.—A man appointed and paid by the miners to check the weighing of the coal at the surface. Cheek. — Wall. Chert.— A silicious rock, often the gangue of lead and zinc. Chestnut Coa l.— Anthracite coal that will pass through a mesh If in. square and over a mesh f in. square (see page 434). Chifion (Mexican).— A narrow drift directed obliquely downwards. Any pipe from which issues water or air under pressure, or at high velocity. Chile Bars.— Bars of impure copper, weighing about 200 lb., imported from Chile, corresponding to the Welsh blister copper, containing 98# Cu. Chilian Mill.— A roller mill for crushing ore. Chill Hardening. — Giving a greater hardness to the outside of cast iron by pouring it into iron molds, which causes the skin of the casting to cool rapidly. Chimney.— (1) An ore shoot. (2) A furnace or air stack. Chinese Pump.— Like a California pump, but made entirely of wood. Chock.— A square pillar for supporting the roof, constructed of prop timber laid up in alternate cross-layers, in log-cabin style, the center being filled with waste. \ * Cho GLOSS AR Y. Cof 579 Chun^rlli -A long iron bar with a cutting end of steel, used in quarrying, andworked by faising and letting it fall. When worked by blows of a CAMt^^l^^pelle^bVmfe)^— fl) 6 A narrow'lnclined passage in a mine, down which coal or ore is either pushed or slides by gravity. (2) The load- ing chute of a tipple. . CT^f^^n?)-AcS^^r<*^ e ^ U &---<>i r erheadstoping. cS-A^vrS i“opTned and closed by the force of the water. . Clack Door — The opening into the valve chamber to facilitate repairs and renewals without unseating the pump or breaking the connections. Clack Piece.— The casting forming the valve chamber. Clack Seal . — The receptacle for the valve to rest on. . , f Clanav (North of England).— When coal is tightly joined to the roof. C^m.—A portion of' ground staked out and held by virtue of a miner’s ciminu^—A tvne of safety lamp invented by Dr. Clanny. . Clastic— Constituted of rocks or minerals that are fragments derived from Cla^ Coursed— A clay seam or gouge found at the sides of some veins. Claying Bar.— For molding clay in a wet bore hole. mooonr , 0fi Clay Band. — Argillaceous iron ore; common m many coal measures. Clean-Up —Collecting the product of a period of work with battery or sluice. Clearance— ( 1) The distance between the piston at the end of its stroke and the end of the cylinder. (2) The volume or entire space filled with steam at end of a stroke including the space between piston and cylinder head, and the steam ducts to the valve seat. . . . Cleat — ( 1) Vertical cleavage of coal seams, irrespective of dip or strike. (2) A small piece of wood nailed to two planks to keep them together, or nailed to any structure to make a support for something else. Cleavage . — The property of splitting more readily in some directions than in Clinometer — An instrument used to measure the angle of dip. CY^-Soft and tough shale or slate forming the roof or floor of a coal seam. Closed Season— When placers cannot be worked. separate shafts by means of which they catch into each other, so that both can revolve together. Coal Breaker.— See Breaker. Coni Cutter — A machine for holing or undercutting coal. Coal Dust.— Very finely powdered coal suspended in the airways of a mine. Coal Measures.— Strata of coal with the attendant rocks. Coal Pipes (North of England). -Very thin irregular coal beds. Coal Road— An underground roadway or heading in coai. Co^ly^Rashings— Soft dark shale, in small pieces, containing much carbona- CoarseTc “se) 1 - When lode stuff is not rich, the ore being only thinly dis- CoaS^l^ol^f salting, the compound — the^ copper concentrated in it after the first smelting to get rid of the bulk ot tne gangue in the ore. Coaster.— One that picks ore from the dump. Cob (Cornish).— 1 To break up ore for sorting. Cobbing Hammer.— A short double-ended hammer for breaking minerals to sizes. CocSrme^or 1 CoXers.— Timber used to hold coal face while it is being undGrcut • Cockle (Cornish).— Black tourmaline, often mistaken for tin. Cod (North of England).— The bearing of an axle. ... Cofer (Derbyshire).— To calk a shaft by ramming clay behind the lining. Cofer.— Mortar box of a battery. . . ' Coffer Dam.— An enclosure built in the water, and then pumped dry, so as to permit masonry or other work to be carried on inside of it. Coffin (Cornish).— An old pit. 580 Cog GLOSSARY. Cor Cog. A chock. Coiiete (Mexican).— A rocket; applied to a blast within a mine or outside. Co# Drag— A tool for picking pebbles, etc. from drill holes. Coke . — The fixed carbon and ash of coal sintered together. Colas (Spanish).— Tailings from a stamp mill or any wet process. Collar.— (1) A flat ring surrounding anything closely. (2) Collar of a shaft is the first wood frame of a shaft. (3) The bar or crosspiece of a framing in entry timbering. Colliery— The whole plant, including the mine and all adjuncts. Colliery Warnings (English).— Telegraphic messages sent from signal-service stations to the principal colliery centers to warn managers of mines when sudden falls of the barometer occur. Color ados (Spanish).— Decomposed ores stained with iron. Colores (Mexican).— Metal-stained ground or rocks. Colrake — A shovel for stirring lead ores while washing. Color— Minute traces or individual specks of gold. Column , or Column Pipe .— The pipe conveying the drainage water from the mine to the surface. Comer (Mexican).— To eat. Comerse los Pilares .— To take out the last vestiges of mineral from the sides and rock pillars of a mine. Conchoidal. — Shell-like, such as the curved fracture of flint. Concrete .— Artificial stone, formed by mixing broken stone, gravel, etc. with lime, cement, tar, or other binder. When hydraulic cement is used instead of lime, the mixture is called beton (English). Concretion.— A cemented aggregation of one or more kinds of minerals around a nucleus. Conduit.— (1) A covered waterway. (2) An airway. Conduit Hole— A flat hole drilled for blasting up a thin piece in the bottom of a level. Conductors (English).— See Guides. Conformable . — Strata are conformable when they lie one over the other with the same dip. Conglomerate .— The rock formation underlying the Coal Measures; a rock containing or consisting of pebbles, or of fragments of other rocks cemented together; English Pudding Rock or millstone grit. Conical Drum .— The rope roll or drum of a winding engine, constructed in the form of two truncated cones placed back to back, the outer ends being usually the smaller in diameter. Consumido (Mexican).— The amount of mercury that disappears by chem- ical combination during the treatment of ore by any amalgamation process. Contact .— Union of different formations. Contact Load or Vein — A vein lying between two differently constituted rocks. Contour.— (1) The line that bounds the figure of an object. (2) In survey- ing, a contour line is a line eveiy point of which is at an equal elevation. Contramina (Mexican).— Countermine. Any communication between two or more mines. Also, a tunnel communicating with a shaft. Cope (Derbyshire) .—Lead mining on contract. Cope , or Coup .— An exchange of working places between hewers. Copelilla ( Spanish ) .-Zinc-blende. Copella (Spanish).— Dry amalgam. Copper Plate.— A sheet of copper that, when coated with mercury, is used in amalgamation. Corbond . — An irregular mass from a lode. Cord . — A cord weighs about 8 tons. Cores. — Cylinder-shaped pieces of rock produced by the diamond-drill system of boring. Corf . — A mine wagon or tub. Cornish Pumps.— A single-acting pump, in which the motion is transmitted through a walking beam; in other respects similar to a Bull Pump. Coro-Coro (South American).— Grains of native copper mixed with pyrite, chalcopyrite, mispickel, etc. Cortar Pillar (Mexican).— To form a rock support or pillar within a mine, at the opening of a cross-cut or elsewhere. ' Cortar Sogas (Mexican).— Literally, to cut the ropes. To abandon the mine, taking away everything useful or movable. Corve.—A mining wagon or tub. Cos GLOSSARY. Cro 581 Costean (Cornish).— To prospect a lode by sinking pits on its supposed course. Costeaning . — Trenching for a lode. Cost Book (Cornish). — Mining accounts. . ^ Cotton Rock.—( 1) Decomposed chert. (2) A variety of earthy limestone. Coulee .— (1) A solified stream or sheet of lava extending down a volcano, often forming a ridge or spur. (2) A deep gulch or water channel. Count™— [if 1 !* cross-vein. (2) (English) An apparatus for recording the number of strokes made by the Cornish pumping engine. (3) A second- ary haulageway in a coal mine. . , x , Counterchute.— A chute down which coal is dumped to a lower level or ffftnfifw&v. Counter gangway A level or gangway driven at a higher level than the main one. Country — The formation traversed by a lode. Country Rock— The main rock of the region through which the veins cut, or that surrounding the veins. Course — The direction of a line in regard to the points of compass. Coursing or Coursing the Air.— Conducting it through the different portions of a mine by means of doors, stoppings, and brattices. Cow— A self-acting brake. Coyoting . — Irregular mining by small pits. A . Crab —A variety of windlass or capstan consisting of a short shaft or axle, either horizontal or vertical, which serves as a rope drum for raising weights; it may be worked by a winch or handspikes. Crab Holes— Holes often met with in the bed rock of alluvial. Also depres- sions on the surface owing to unequal disintegration of the underlying rock. Cradle .— A box with a sieve mounted on rockers for washing auriferous alluvial. „ _ _ Cradle Dump . — A rocking tipple for dumping cars. See Dump. Cramp (English).— (1) A short bar of metal having its two ends bent down- wards at right angles for insertion into two adjoining pieces of stone, wood, etc. to hold them together. (2) A pillar left for support in a mine. Cranch— Part of a vein left by previous workers. Crane (English).— A hoisting machine consisting of a revolving vertical post or stalk, a projecting jib, and a stay for sustaining the outer end of the jib; these do not change their relative positions as they do in a derrick. There is also a rope drum with winding rope, etc. v ^ Creaze (Cornish).— (1) Tin ore collected in the middle of the huddle. (2) The middle of a huddle. „ . _ . . Creep .—The gradual upheaval of the floor or sagging of the roof of mine workings due to the weighting action of the roof and a tender floor. Creston (Mexican).— The outcrop or apex of a vein or mineral deposit. Crevice .— A fissure. . C revicing . — Picking out the gold caught in cracks and crevices m the rocks over which it has been washed. ' x . ... Criadero (Mexican).— (1) A mineral deposit of irregular form, not vem-like. (2) A chamber in a vein filled with ore of more or less richness. (3) Any mineral deposit. This latter is the more modern sense, and the word is so used in the mining laws at present in force in Mexico. Crib —(1) A structure composed of horizontal timbers laid on one another, or a framework built like a log cabin. See Chock. (2) A miner’s lunch- eon. (3) See Curb. x . Cribbing . — Close timbering, as the lining of a shaft, or the construction ot cribs of timber, or timber and earth or rock to support a roof. Cribble A sieve. Crisol (Mexican).— A crucible of any kind. Crop. — See Outcrop. , x Crop Fall.— A caving in of the surface at or near the outcrop of a bed of coal. Cropping Coal . — The leaving of a small thickness of coal at the bottom of the seam in a working place, usually in order to keep back water. The coal so left is termed “ Cropper Coal.” Croppings .— Portions of a vein as seen exposed at the surface. Cropping Out .— Appearing at the surface; outcropping. . Cross-Course . — A vein lying more or less at right angles to the regular vein of the district. 582 Cro GLOSSARY. Deb Crosscut.— (1) A tunnel driven through or across the measures from one seam to another. (2) A small passageway driven at right angles to the main gangway to connect it with a parallel gangway or air-course. Crosses and Holes (Derbyshire).— Made in the ground by the discoverer of a lode to tempoiarily secure possession. Cross-Heading. — A passage driven for ventilation from the airway to the gang- way, or from one breast through the pillar to the adjoining working. Cross-Heading , or Cross-Gateway .—A road kept through goaf and cutting off the gateways at right angles or diagonally. Cross-Hole. — See Crosscut (2). Cross- Latches. — See Latches. Cross-Spur. — A vein of quartz that crosses the reef. Cross- Vein. — An intersecting vein. Crouan (Cornish).— Granite. Crowbar. — A strong iron bar with a slightly curved and flattened end. Crowfoot— A tool for drawing broken boring rods. Crown Tree.— A piece of timber set on props to support the roof. Crucero (Mexican). — A crosscut for ventilation to get around a horse, or to prospect for the vein. Crucible.— ( 1) The bottom of a cupola furnace in which the molten materials collect. (2) Pots for smelting assays in. Crush. — See Squeeze , Thrust. Crusher— A machine used for crushing ores and rock. Crushing— Reduction of mineral in size by machinery. Crystal. — A solid of definite geometrical form, which mineral (or sometimes organic) matter has assumed. Culm.— Anthracite-coal dirt. Culm Bank , or Culm Dump— Heaps of culm now generally kept separate from the rock and slate dumps. Cuna (Mexican). — Literally, a wedge. A short drill or picker generally known in the United States as a “gad.” Cupel— A cup made of bone ash for absorbing litharge. Curb.— (1) A timber frame intended as a support or foundation for the lining of a shaft. (2) The heavy frame or sill at the top of a shaft. Curbing.— The wooden lining* of a shaft. Cut. — (1) To strike or reach a vein. (2) To excavate in the side of a hill. Cutter. — A term employed in speaking of any coal-cutting or rock-cutting machines; the men operating them, or the men engaged in underholing by pick or drill. Cutting Down.— To cut down a shaft is to increase its sectional area. Dam.— A timber bulkhead, or a masonry or brick stopping built to prevent the water in old workings from flooding other workings, or to confine the water in a mine flooded to drown out a mine fire. Damp.— Mine gases and gaseous mixtures are called damps. See also After- damp, Blackdamp , Firedamp , Stinkdamp. Dan (North of England).— A truck without wheels. Danger Board. — See Fireboard. Dant (North of England). — Soft inferior coal. Datum Water Level.— The level at which water is first struck in a shaft sunk on a reef or gutter. Davy.— A safety lamp invented by Sir Humphrey Davy. Day. — Light seen at the top of a shaft. Day Fall. — See Crop Fall. Day Shift.— The relay of men working in the daytime. Dead. — The air of a mine is said to be dead or heavy when it contains car- bonic-acid gas, or when the ventilation is sluggish. Dead. — (1) Unproductive. (2) Unventilated. Dead Men’s Gi'aves (Australian). — Grave-like mounds in the basalt under- lying auriferous gravels. Dead Quartz.— Quartz carrying no mineral. Dead Riches.— Lead carrying much bullion. Dead Roast. — To completely drive off all volatile substances. Deads. — Waste or rubbish from a mine. Dead Work. — Exploratory or prospecting work that is not directly productive. Brushing roof, lifting bottom, cleaning up falls, blowing rock, etc. Dean (Cornish).— The end of a level. Debris— Fragments from any kind of disintegration. GLOSSARY. Dip 583 Dee Beep (English).— “ To the deep,” toward the lower portion of a mine; hence, Bella. — A triangularly shaped piece of alluvial land at the mouth of the Yiver • Bemasia (Mexican). — A piece of unoccupied ground between two mining concessions. Denudation The laving bare by water or other agency. Benuncio (Mexican).— Denouncement. The act of applying for a mining concession under the old mining laws. Deposit.— { 1) Irregular ore bodies not veins. (2) A bed or any sedimentary DenSvTEnglish).— (1) A man who fixes and withdraws % e ti m ker sup- porting^!^ roof of a mine, and attends to the safety of the roof and sides, builds stoppings, puts up bratticing, and looks after t^ safety of the hewers, etc. (2) An underground othcial who sees to the general safety of a certain number of stalls or of a district, but does not set the timber himself, although he has to see that it is properly and suffi- ciently done. (3) (American) A deputy sheriff. . Berrick. — (1) A crane in which the rope or chain forming let out or hauled in at pleasure, thus altering the inclination of Ihe jib (2) The structure erected to sink a drill hole and the framework above shafts are sometimes called by this name. . . - 0 Derrumbe , or Derrumbamineto (Mexican). — The caving m of the whole or a portion of a mine. . . Desaguador (Spanish). — A water pipe or dram. Besague ( Mexican ) . — Drainage of a mine by any means. - Bescargar (Mexican).— Literally, “to unload. Bescargar un Homo. To Descubridoral Mexican^— The first mine opened in a new district or on a new mineral deposit. Besecho (Spanish).— Foul red mercury. Besfrute (Mexican).— Taking out ore. Obras de Desfrute — Stopes, etc. Besmontar (Mexican).— Literally, to clear away underbrush. In mining, to take away useless and barren rocks; to remove rubbisn. Besmontes (Spanish).— Poor ores. Bespensa (Mexican) .—(1) A pantry or storeroom. (2) up rich ore. Bespoblado (Spanish).— Ore with much gangue. , Bespoblar ( Mexican ) . — To suspend work m a mine. Bessue (Cornish) —To cut away the ground beside remove the latter whole. , . _ _ . . _ , „ Bestajo (Mexican).— (1) A contract to do any kind of work in or ab 9 ut a mine or elsewhere for a fixed price. (2) Piece work, as distinguished from time work. Bestajero .— A contractor for piece work. Detaching Hook.— A self-acting mechanical contrivance for setting free J winding rope from a cage when the latter is raised beyond a certain point in the head-gear; the rope being released, the cage remains suspended in the frame. Devil's Dice . — Cubes of limomte, pseudomorphs after pyrites. Diagonal Joints.- Joints diagonal to the strike of the cleavage. Dial (English). — An instrument similar to a surveyors compass, witfi vernier attached. Die.— The bottom iron block of a battery, or grinding pan on which the sllOG 9/Ct)S Digging. — Mining operations in coal or other minerals. Diggings— Where gold and other minerals are dug out from shallow alluvials. Lillies, oT M^Short self-acting inclines where one or two tubs at a time are run. . Dillueing (Cornish). — Dressing tin slimes in a fine sieve. Dip —(l) To slope downwards. (2) The inclination of strata with a hon zontal plane. (3) The lower workings of a mine. Dip Joint . — V ertical joints about parallel to the direction of the cleavage dip. Dippa (Cornish). — A small catch-water pit. Dipping 'Needle. — A magnetic needle suspended in a vertical plane, tor locating iron deposits. A secure room to lock thin vein so as to 584 Dir GLOSSARY. Dre Dirt Fault —A confusion in a seam of coal, the top and bottom of the seam being well defined, but the body of the vein being soft and dirty. Dish (Cornish) —An ore measure; in lead mines, a trough 28 in. long, 4 in. deep and 6 in. broad; sometimes 1 gallon, sometimes 14 to 16 pints. Disintegration. — Separation by mechanical means, not by decomposition. Ditch — (1) The drainage gutter in a mine. (2) A drainage gutter on the surface. (3) An open conveyor of water for hydraulic or irrigation purposes. , Divide . — The top of a ridge, hill, or mountain. Dividing Slate— A stratum of slate separating two benches of coal. See PVLVtVflQ Divining , or Dowsing , Rod— A small forked hazel twig that, when held loosely in the hands, is supposed to dip downwards when passing over water or metallic minerals. Dizzue (Cornish).— See Dessue. . , , Doa—(l) An iron bar, spiked at the ends, with which timbers are held together or steadied. (2) A short heavy iron bar, used as a drag behind a car or trip of cars when ascending a slope to prevent their running back down the slope in case of accident. See Drag. Dog Hole.— A little opening from one place in a mine to another, smaller than a breakthrough. , „ . , , _ . . , Doa Iron.— A short bar of iron with both ends pointed and bent down so as to hoid together two pieces of wood into which the points are driven. Or one end may be bent down and pointed, while the other is formed into an eye, so that if the point be driven into a log, the other end may be usedvto haul on. ^ _ Doles. — Small piles of assorted or concentrated ore. . , Dollv — (1) A machine for breaking up minerals, being a rough pestle and mortar, the former being attached to a spring pole by a rope. (2) A tool used to sharpen drills. . . , , . ^ „ Dolly Tub (Cornish).— A tub in which ore is washed, being agitated by a dollv or perforated boards. Donk (North of Ehgland).— Soft mineral found m cross-veins. Donkey Engine (English).— (1) A small steam engine attached to a large one, and fed from the same boiler; used for pumping water into the boiler. (2) A small steam engine. „ . , . , , , Door Piece (English).— The portion of a lift of pumps in which the clack or valve is situated. „ , . . , « . . j) 00rs —Wooden doors in underground roads or airways to deflect the air- current. . , Door Tender— A boy whose duty it is to open and close a mine door before and after the passage of a train of mine cars. , Dope. — An absorbent for holding a thick liquid. The material that absorbs the nitroglycerine in explosives. ...... Double Shift.— When there are two sets of men at work, one set relieving the Double *Tape Fuse— Fuse of superior quality, or having a heavier and stronger Double timber. —Two props with a bar placed across the tops of them to sup- port the roof and sides. „ , . . , „ , . . Downcast. — The opening through which the fresh air is drawn or forced into Dradge fCornish ) 6 ^ {if Inferior ore separated from the prill. (2) Pulverized refuse ^ Draftage.—A deduction made from the gross weight of ore when transported, 1 ) ' t he frictional resistance offered to a current of air in a mine. Dra^-il) To^‘ draw ” the pillars; robbing the pillars after the breasts are exhausted. (2) An effect of creep upon the pillars of a mine. Draw a Charge.— To take a charge from a furnace. Drawlift.—A pump that receives its water by suction and will not iorce it Dr(m-Hrte*— Anaperture in a battery through which the coal is drawn. Drawing an Entry. — Removing the last of the coal from an entry Drawn.— The condition in which an entry or room is left after all the coal has been removed. See Robbed. Dresser (Staffordshire).— A large coal pick. L)RE GLOSSARY. Egg 585 Pressing— Preparing poor or mixed ores mechanically for metallurgical nresSZa^Floors —The floors or places where ores are dressed. Drift (1) A horizontal passage underground. A drift follows the vein, as distinguished from a Crosscut, which intersects it, or a level or gahery, which may do either. (2) In coal mining, a gangway above water level driven from the surface in the seam. (3) Unstratified diluvium. Drifting.— Winning pay dirt from the ground by means of drives. Drill— An instrument used in boring holes. Drive ( Drift). A horizontal passage in a lode. Drive —To cut an opening through strata. . Driving . — Excavating horizontal passages, in contradistinction to sinking or Driving on' iine.-Keeping a heading or breast accurately on a given course bv means of a compass or transit. . . n , Dronper — (1) A spur dropping into the lode. (2) A feeder. (3) A branch leaving the vein on the footwall side. (4) Water dropping from the roof Drop Shaft— A monkey shaft down which earth and other matter are lowered by means of a drop (i. e., a kind of pulley with break attached), the empty bucket is brought up as the full one is lowered. Druqqon (Staffordshire).— A vessel for carrying fresh water into a mine. Drum.— The cylinder or pulley on which the winding ropes are coiled or Drmn Rings.— Cast-iron rings with projections to which are bolted the laggings forming the surface for the ropes to lap on. _ Drummy.— Sounding loose, open, shaky, or dangerous when tested. Druse.— A hollow cavity lined with small crystals. Dry Amalgamation.— Treating ores with hot, dry mercury. Dry Diggings— Placers never subject to overflow. Dry Orel— Argentiferous ores that do not contain enough lead for smelting DuckMuMne .— An arrangement of two boxes, one working within the other, for forcing air into mines. Duelas (Mexican).— Staves of a barrel or cask, etc. Dumb’d. — Choked, of a sieve or grating. . Dumb Drift.- A short tunnel or passage connecting the mam return airways of a mine with the upcast shaft some distance above the furnace, m order to prevent the return air laden with mine gases from passing through or over the ventilating furnace. . « .. Dump— (1) A pile or heap of ore, coal, culm, slate, or rock. (2) The tipple by which the cars are dumped. (3) To unload a car by tipping it up. (4) The pile of mullock as discharged from a mine. Dumper.— A car so constructed that the body may be revolved to dump the material in front or on either side of the track. Durn (Cornish).— A timber frame. Durr (German).— Barren ground. Dust.— See Coal Dust. Dust Gold. — Pieces under 2 to 3 dwt. . . _ , . Duty. — The unit of measure of the work of a pumping engine expressed m foot-pounds of work obtained from a bushel, or 100 lb., or other unit of Dyke* or Dike.—{ 1) A wall of igneous rock passing through strata, with or without accompanying dislocation of the strata. (2) A fissure filled with igneous matter. (3) Barren rock. Dzhu (Cornish).— See Dessue. Ear.— The inlet or intake of a fan. . , . , , Echadero (Mexican). — A level place near a mine where ore is cleaned, piled, weighed, and loaded on mules or other conveyance. Also called patio ot the mine. Echado (Mexican).— The dip of the vein. . Edge Coals (English).— Highly inclined seams of coal, or those having a dip greater than 30^* Efflorescence.— An incrustation by a secondary mineral, due to loss of water of crystallization. ¥gf Cool— Anthrac?^ 61 coal that will pass through a 2*" square mesh and over a 2" square mesh (see page 434). 586 Elb GLOSSARY. Fal Elbow— A sharp bend, as in a lode or pipe. Electric Blast— Instantaneous blasting of rock by means of electricity. Elevator Pump— An endless band with buckets attached, running oyer two drums for draining shallow ground. Elvan — A Cornish name applied to most dike rocks of that county, irre- spective of the mineral constitution, but in the present day restricted to quartz porphyries. Emborrascarse (Mexican).— To go barren by the vein terminating or pinching out, etc. Empties— Empty mine or railroad cars. Encino (Mexican).— Live oak. End Joint (End Cleat).— A joint or cleat in a seam about at right angles to the principal or race cleats. Endless Chain— A system of haulage or pumping by the moving of an endless chain. Endless Rope— A system of haulage same as endless chain, except that a wire rope is used instead of chain. End, or End-On— Working a seam of coal at right angles to the principal or face cleats. Engine Plane— An incline up which loaded cars are drawn by a rope operated by an engine located at the top or bottom of the incline. The empty cars descend by gravity, pulling the rope after them. Engineer— { 1) One who has charge of the surveying or machinery about a mine. (2) One who runs an engine. Ensayes (Mexican).— Assays. Entibar (Mexican).— To timber a mine or any part thereof. Entry —A main haulage road, gangway, or airway. An underground passage used for haulage or ventilation, or as a manway. Entry Stops— Pillars of coal left in the mouths of abandoned rooms to support the road, entry, or gangway till the entry pillars are drawn. Erosion.— The wearing away of rocks by rains, etc. Escaleras (Mexican).— Ladders, generally made of notched sticks. Escarpment — A nearly vertical natural face of rock or soil. Escoria (Mexican).— Slag or cinders. Escorial. — Slag pile. Escorificador (Mexican).— A scorifier, in assaying. Espejuelo (Mexican).— A mineral gangue, with a faintly reflecting surface. Espeton (Mexican).— The tapping bar of a smelting furnace. Estano (Spanish). — Tin. Estrujon (Mexican).— A second collection of amalgam, generally very pasty. Exploder.— A chemical employed for the instantaneous explosion of powder. Exploitation— The working of a mine, and similar undertakings; the exami- nation instituted for that purpose. Exploration— Development. Explosion.— Sudden ignition of a body of firedamp. Eye (English).— (1) A circular hole in a bar for receiving a pin and for other purposes. (2) The eye of a shaft is the very beginning of a pit. (3) The eye of a fan is the central or intake opening. Face.— (1) The place at which the material is actually being WOTked, either in a breast or heading or in longwall. (2) The end of a drift or tunnel. Face-On. — When the face of the breast or entry is parallel to the face cleats of the seam (see page 285). . Face Wall.— A wall built to sustain a face cut into the natural earth, in distinction to a retaining wall, which supports earth deposited behind it. Faenas (Mexican).— Dead work, in the way of development. Fahlband (German). — A course impregnated with metallic sulphides. Faiscador (Spanish).— A gold washer. Fall.—{ 1) A mass of roof or side which has fallen in any part of a mine. (2) To blast or wedge down coal. False Bedding.— Irregular lamination, wherein the laminae, though for short distances parallel to each other, are oblique to the general strati- fication of the mass at varying angles and directions. False Bottom.— (1) A movable bottom in some apparatus. (2) A stratum on which pay dirt lies, but which has other layers below it. False Cleavage.— A secondary slip cleavage superinduced on slaty cleavage. False Set.— A temporary set of timber used until work is far enough advanced to put in a permanent set. Fam GLOSSARY ; Fla 587 Famp (North of England).—' Thin beds of soft tough shale. Fan!— A machine for creating a circulation of air in a mine. Fan Drift— A short tunnel or conduit leading from the top of the air-shaft to the fan. , „ , A , . , Fanega (Mexican).— A Spanish measure of about 2£ bushels. Fang (Derbyshire). — An air-course. Fascines (English).— Bunches of twigs and small branches for forming foundations on soft ground. , j past —(1) A road driven in a seam with the solid coal at each side. Fast at an end,” or “ fast at one side,” implies that one side is solid coal and the other open to the goaf or some previous excavation. (2) Bed rock. Fast End— A n end of a breast of coal that requires cutting. Fat Coals.— Those containing volatile oily matters. jfaS?.— i^fracture or disturbance of the strata breaking the continuity of the formation. , , Feather —A slightly projecting narrow rib lengthwise on a shaft, arranged to catch into a corresponding groove in anything that surrounds' and slides along the shaft. , Feather Edge — (1) A passage from false to true bottom. (2) The thin end of a wedge-shaped piece of rock or coal. Feather Ore. — Sulphide of lead and antimony. ^ Feed.— Forward motion imparted to the cutters or drills of rock-drilling or coal-cutting machinery, either hand or automatic. Feeder. — (1) A runner of water. (2) A small blower of gas. Feigh (North of England). — Ore refuse. ^ , Fencing . — Fencing in a claim is to make a drive round the boundaries of an alluvial claim, to prevent wash dirt from being worked out by adjoining claim holders. , „ J , . , , Fend-OJf (English).— A sort of bell-crank for turning a pump rod past the angle of a crooked shaft. Fierros (Mexican).— Iron matte. Fiery.— Containing explosive gas. 1 Fines— Very small material produced in breaking up large lumps. Fire— (1) A miners’ term for firedamp. (2) To blast with gunpowder or other explosive. (3) A word shouted by miners to warn one another when a shot is fired. , . , . . Fire-Bars (English) .—The iron bars of a grate on which the fuel rests. Fireboard.—A piece of board with the word fire painted upon it and sus- pended to a prop, etc., in the workings, to caution men not to take a naked light beyond it, or to pass it without the consent of the foreman or his assistants. _ , Fire Boss.— An underground official who examines the mine for gas and inspects safety lamps taken into the mine. Fireclay— Any clay that will withstand a great heat without vitrifying. Firedamp.— (1) A mixture of light carburetted hydrogen ( CIL) and air m explosive proportions; often applied to CH± alone or to any explosive mixture of mine gases. Fireman . — See Fire Boss. . Fire-Setting.— The process of Exposing very hard rock to intense heat, ren- dering it thereby easier for breaking down. First Working . — See Whole Working. Firsts— The best ore picked from a mine. Fish.— 1 To join two beams, rails, etc. together by long pieces at their sides. Fissure— An extensive crack. Fissure Vein— Any mineralized crevice in the rock of very great depth. Flags— Broad flat stones for paving. A , _ Flagstone— Any kind of a stone that separates naturally into thm tabular plates suitable for pavements and curbing. Especially applicable to sandstone and schists. Flang (Cornish).— A double-pointed pick. Flange (English).— A projecting ledge or rim. Flat.— (1) A district or set of workings separated by faults, old workings, or barriers of solid coal. (2) The siding or station laid with two or more lines of railway, to which the putters bring the full cars from the work- ing face, and where they get the empty cars to take back. (3) The area of working places, from which coal is brought to the same station, is also called “flat.” 588 Fla GLOSSARY. FrE Flat Rod.— A horizontal rod for conveying power to a distance. Flats— Narrow decomposed parts of limestones that are mineralized. Flat Sheet— Sheet-iron flooring at landings and in the plats, chambers, and junctions of drives, to facilitate the turning and management of trucks. Flat Wall (Cornish).— Foot-wall. Flintshire Furnace— A kind of reverberatory furnace used for smelting lead jpfo^—Broken and transported particles or boulders of vein matter. Float Gold— Gold in thin scales, which floats on water. Float Ore.— A term applied by miners to ore found loose in the clay or soil. Float Stowes— Loose boulders from lodes lying on or near the surface. Flood Gate (English).— A gate to let off excess of water in flood or other times. Floor — (i) The stratum of rock upon which a seam of coal immediately lies. (2) That part of a mine upon which you walk or upon which the road bed is laid. Floram (Cornish).— Very fine tin. Flour Gold. — The finest alluvial gold. , Flouring.— Mercury reduced to fine globules that are easily contaminated and will not amalgamate. , . A ‘ . Flucan.—A soft, greasy, clayey substance found m the joints of veins. Fluke.— A rod for cleaning out drill holes. Flume.— An artificial watercourse. „ . Pluming — Lifting a river out of its bed with wooden launders or pipes, in order to get at the bed for working. ^ . ,, Flush .— (1) To clean out a line of pipes, gutters, etc. by letting m a sudden rush of water. (2) The splitting of the edges of stone under pressure. (3) Forming an even continuous line or surface. (4) To fill a mine with fine material. Fluthwerk (German). — Fiver prospecting. . Flux— Iron ore, limestone, and sand, which are added m various propor- tions to the charge in a furnace to make the gangue melt up and flow off easily. „ , „ Fodder (North of England).— 21 cwt. of lead. Following Stone.— R oof stone that falls on the removal of the seam. Foot (Cornish).— 2 gallons, or 60 lb., black tin. . Foot-Hole. — Holes cut in the sides of shafts or winzes to enable miners to ascend and descend. , , , , , ... Foot- Piece.— (1) A wedge of wood or part of a slab placed on the toot-wail against which a stull piece is jammed. (2) A piece of wood placed on the floor of a drive to support a leg or prop of timber. Foot- Wall. — The lower boundary of a lode. Footway.— Ladders in mines. Force Fan— See Blowdown Fan. Force Piece— Diagonal timbering to secure the ground. Force Pump— A pump that forces water above its valves. . Forehay.— Penstock. The reservoir from which water passes directly to a waterwheel. Foreyolinq. — Driving the poles over the timbers so that their ends project beyond the last set of timber, so as to protect the miner from roof falls; used also in quicksand or other loose material. . , Forewinninq— The first working of a seam in distinction from pillar drawing. Fork .— (1) A deep receptacle in the rock, to enable a pump to extract the bottom water. A pump is said to be “ going in fork ” when the water is so low that air is sucked through the windbore. (2) (Cornish) Bottom of sump. (3) (Derbyshire) Prop for soft ground. . Formation.— A series of strata that belong to a single geological age. Fossickers (Australian).— Grubbers for gold in the beach sand. Fossicking— Overhauling old workings and refuse heaps for gold. Fossil. — Organic remains or impressions of them found in mineral matter. Fother (North of England). — i chaldron. .... , Frame. — A table composed of boards, slightly inclined, over which water runs to wash off waste from sluice tin. Frame Set.— The legs and cap or collar arranged so as to support a passage mined out of the rock or lode; also called Framing. . _ .. Free— Coal is said to be “ free ” when it is loose and easily mined, or when it will “run” without mining. Free Milling . — Ores requiring no roasting or chemical treatment. FRE GLOSSARY. Gob 589 Free Miner.— Licensed miner. Fresno (Mexican).— An ash tree. Fronton (Mexican).— Any working face. lT^oal fc or near the bottom of an upcast shaft, for pro- dncing a current of air for ventilating the mine. tridges. '2) To melt. GaZap^^(MexiSn^^A S turtle-shaped pig of lead. Gale.— A grant of mining ground. Galiage.— Royalty. &Mex"-Ki 0 rs^me^ of silver or gold ore, particularly those -The* frame sufporiing a pulley over which the hoisting rope Gam&lMexi^-A prospector for gold placers or ores. Qanguet- Wasteniaterial from lodes. GamS^-^hard^ompacL^^^ ® rec ^ a ^.' smelting Gas Coal —Bituminous coal containing a large percentage of ga . «5a aSSSSasif 48=*— 01 - GaZX-l wo n o“lorTxed in an airway for regulatlng the supply “ iS <>octa— Large nodules of stone v Geordie — A safety lamp invented by George btepnensou. with a wedge-shaped key for holding pieces together. RV«“-A vertical drum and framework by which the minerals or waste rock when it arrives at the surface. degcribed as a p0 st roof “thmlta? or^metal roof with post girdles, according as the post or the metal predominates. t», < 2SffidSffSS* which take up the shock of impact whpn the falling tools strike the bottom of the hole. . . , JenMn - A road cut-in a pillar of coal in a bordways direction, that is, at Jia -fl) 1 A^elf-actingfnffiSe. ^Y^^machine for separating ores or minerals 5 'from iorthlcsrfock by meaiis of their difference in specific gravity; Jiane?- m A* Mnd'of Ijo^pling hook for connecting cars on an incline 99 W) An allowance of FiquSr sometimes issued to workmen (almost Separatmg C hea*vy from light particles by agitation in water. 594 Joe GLOSSARY. Lag Jockey.— A self-acting apparatus carried on the front truck of a set for re- leasing it from the hauling rope. Joggle . — A joint of trusses or sets of timber for receiving pressure at right angles, or nearly so. Joints.— (1) Divisional planes that divide the rock in a quarry into natural blocks. There are usually two or three nearly parallel series, called by quarrymen end joints, back joints, and bottom joints, according to their position. (2) In coal seams, the less pronounced cleats or vertical cleavages in the coal. The shorter cleats, about at right angles to the face cleats and the bedding plane of the coal. Jud.—( 1) A portion of the working face loosened by “ kirving” underneath, and “nicking” up one side. The operation of kirving and nicking is spoken of as “making a jud.” (2) The term jud is also applied to a working place, usually 6 to 8 yd. wide, driven in a pillar of coal. When a jud has been driven the distance required, the timber and rails are removed, and this is termed “ drawing a jud.” Judge (Derbyshire and North of England) .—A measuring staff. Jugglei's, or Jugulars .— Timbers set obliquely against the rib in a breast, to form a triangular passage to be used as a manway, airway, or chute. Jump .— An upthrow or a downthrow fault. Jumper.— A hand drill used in boring holes in rock for blasting. Kann (Cornish).— Fluorspar. Kazen (Cornish).— A sieve. Keckle-Meckle — Poorest lead ore. Keeker— An official that superintends the screening and cleaning of the coal. Keel Wedge . — A long iron wedge for driving over the top of a pick hilt. Keeps , or Keps.— Wings, catches, or rests to hold the cage at rest when it reaches any landing. Keeve.—A large wooden tub used for the final concentration of tin oxide. Kenner . — Time for quitting work. Kerf .— The undercut made to assist the breaking of the coal. Kerned (Cornish).— Pyrites hardened by exposure. Kerve (North of England). — In coal mining, to cut under. Kevil (Derbyshire).— Calcspar found in lead veins. Key.—{ 1) An iron bar of suitable size and taper for filling the key ways of shaft and pulley so as to keep both together. (2) A kind of spanner used in deep boring by hand. Kibble— See Bowk. Often made with a bow or handle, and carrying over a ton of debris. Kickup .— An apparatus for emptying trucks. Kieve .— Tossing tub. Killas (Cornish).— Clay slate. Kiln.— A chamber built of stone or brick, or sunk in the ground, for burning minerals in. Kind. — (1) Tender, soft, easy. (2) Likely looking stone. Kind-Chaudron.—A system of sinking shafts through water-bearing strata. Kirving (North of England).— The cutting made beneath the coal seam. Kist — The wooden box or chest in which the deputy keeps his tools. The chest is always placed at the flat or lamp station, and this spot is often referred to by the expression “at the kist.” Kit .— Any workman’s necessary outfit, as tools, etc. Kitty . — A squib made of a straw tube filled with powder. Knee Piece . — A bent piece of piping. Knocker.— A lever that strikes on a plate of iron at the mouth of a shaft, by means of which miners below can signal to those on the top. Knocker Line— Tine signal line extending down the shaft from the knocker. Koepe System . — A system of hoisting without using drums, the rope being endless and passing over pulleys instead of around a drum. Labor (Mexican).— Mine workings in general. Specifically, a stope or any other place where ore is being taken out. Ladderway, Ladder Road . — The particular shaft, or compartment of a shaft, used for ladders. Lagging— (1) Small round timbers, slabs, or plank, driven in behind the legs and over the collar, to prevent pieces of the sides or roof from falling through. (2) Long pieces of timber closely fitted together and fastened to the drum rings to form a surface for the rope to wind on. Lam GLOSSARY. Lid 595 ' Lamas (Spanish).— (1) Slimes. (2) Argentiferous mud treated by amalga- mation. Lamer o (Mexican) .—Place of deposit for lamas. Laminae. — Sheets not naturally separated, but which may be forced apart. Lampazo (Mexican).— A sort of broom formed of green branches on the end of a long stick, to dampen the flame in a reverberatory furnace. Lamp Men. — Cleaners, repairers, and those having charge of the safety lamps at a colliery. , . , „ • , Lamp Stations.— Certain fixed stations m a mine at which safety lamps are allowed to be opened and relighted by men appointed for that purpose, or beyond which, on no pretense, is a naked light allowed to be taken. Lander.— The man that receives a load of ore at the mouth of a shaft. Lander's Crook— A hook or tongs for upsetting the bucket of hoisted rock. Landing— (1) A level stage for loading or unloading a cage or skip. (2) The top or bottom of a slope, shaft, or inclined plane. Land Sate.— The sale of coal loaded into carts or wagons for local consump- tion. Land-Sale Collieries— Those selling the entire product for local consumption, and shipping none by rail or water. Lap. — One coil of rope on a drum or pulley. Lappior (Cornish). — An ore dresser. Large. — The largest lumps of coal sent to the surface, or all coal that is hand picked or does not pass over screens; also, the large coal that passes over screens. , „ , . . _ Larry— (1) A car to which an endless rope is attached, fixed at the inside end of the road, forming part of the appliance for taking up slack rope. See Balance Car. (2) See Barney. (3) A car with a hopper bottom and adjustable chutes for feeding coke ovens. (4) A hopper-shaped car for charging coke ovens. , , . Latches. — (1) A synonym of switch. Applied to the split rail and hinged switches. (2) Hinged switch points, or short pieces of rail that form rail crossings. Lateral.— From the side. Lath.— A plank laid over a framed center or used in poling. Launder. Water trough. Laundry Box.— The box at the surface receiving the water pumped up from below. Lava.— A common term for all rock matter that has flowed from a volcano or fissure. Lavadero (Mexican).— A washer. A tank with a stirring arrangement to loosen up the argentiferous mud from the patio, and dilute the same with water, so that the silver amalgam may have a chance to precipitate. An agitator. Lazadores (Mexican).— Men formerly employed in recruiting Indians for work in the mines by the gentle persuasion of a lasso. Lazy Back (Staffordshire).— A coal stack, or pile of coal. Leaching.— To dissolve out by some liquid. Lead (pronounced teed).— ( 1) Ledge (America); reef (Australia); lode or vein (England). A more or less vertical deposit of ore formed after the rock in which it occurs. (2) A bed of alluvial pay dirt or an auriferous gutter. (3) The distance to which earth is hauled or wheeled. Leader.— A seam of coal too small to be worked profitably, but often being a guide to larger seams lying in known proximity to it. Leat.—A small water ditch. Leavings (Cornish).— Hal vans. Ledge.— See Lead. Leg.— A wooden prop supporting one end of a collar. Leg Piece.— An upright log placed against the side of a drive to support the cap piece. Lenador (Mexican).— One that cuts, carries, or furnishes wood for com- bustible. Level. — A road or gangway running parallel or nearly so with the strike of the seam. Ley (Mexican) .—Law. As applied in mining matters, it means the propor- tion of precious or other metals contained in any mineral substance or metallic alloy. Lid .— A cap piece used in timbering. 596 LIP GLOSSARY. Lum Lift — rn The vertical height traveled by a cage in a shaft. (2) The lift of a 'Dump is theoretical height from the level of the water m the sump to the noint of discharge. (3) The distance between the first level and the surface, or between two levels. (4) The levels of a shaft or slope. Liftinq Guards. — Fencing placed around the mouth of a shaft, which is lifted out of the way by the ascending cage. Lignite— A coal of a woody character containing about 66$ carbon and y having a brown streak. . „ , , Limadura ( Mexican) . — Filings. The mercurial globules seen when a piece of argentiferous mud from a patio is washed m a spoon or saucer for T irru^Cartridae — A charge or measured quantity of compressed dry caustic lime made up into a cartridge and used instead of gunpowder for breaking down coal. Water is applied to the cartridge, and the expan- sion breaks down the coal without producing a flame. Lime Coal.— Small coal suitable for lime burning. Lines —Plumb-lines, not less than two m number, hung from hooks driven in wooden plugs. A line drawn through the centers of the two strings or wires, as the case may be, represents the bearing or course to be driven on. , . . _ . Lining.— The planks arranged against frame-sets. Linnets (Derbyshire).— Oxidized lead ores. Linternilla ( Mexican) .—The drum of a Horse Whim. Lip Screen. — A small screen or screen bars, placed at the draw hole of a coal pocket to take out the fine coal. Lis (Mexican).—' The flouring of mercury. , , Little Giant.— The name given to a special sort of hydraulic nozzle used for Live^Quartz.—A variety of quartz usually associated with mineral. AZa^es^Mexic^in ) .—Horizontal cross-beams in a shaft, or the upright pieces that sustain the roof beams in a drift or tunnel. Loaded Track.- Track used for loaded cars. . Loader— One that fills the mine cars at the working places. Loam. — Any natural mixture of sand and clay that is neither distinctly sandy Locatiln^-The first approximate staking out or survey of a mining claim, in distinction from a Patent Survey , or a Patented Claim. in the country rock filled with mineral; usually applied to metalliferous lodes. In general miners vein or ledge is a tabular deposit of valuable minerals between definite boundaries Whether it be a fissure formation or not is not always known, and does not affect the legal title under the United States federal and local statutes and customs relative to lodes. But it m ^ s t not be a placer, i. e., it must consist of quartz or other rock in place, and bearing Xodlstofor^ Magnetic iron ore. (2) Stone found in veins or lodes. Logs. — Portions of trunks of trees cut to lengths and built the mouth or collar of a shaft from the surface, in order to give the reauisite space for the dumping of mullock and ore. Lonq-Pillar Work— A system of working coal seams in three separate oper- tions* (1) large pillars are left; (2) a number of parallel headings are driven through the block; and (3) the ribs or narrow pillars are worked LonTZt^-T woSdenltafce about 24 ft. long, 2 ft. wide, and 1 ft. high, for washing auriferous gravel. ^ngwall.— 't system of working a seam of coal in J?® taken out and no pillars left, excepting the shaft pillars, and sometimes the main-road pillars. Loob (Cornish).— Sludge from tin dressing. Loose End— ( 1) A portion of a seam worked on two sides. (2) A portion that projects in the shape of a wedge between previous workings. Lumber—' Timber cutto" the various sizes and shapes Lumbreras (Mexican) .-Ventilating shafts in a mine or other underground work. GLOSSARY. Mer 597 IrtJM vr MJWK,**** - . TnllYnrn r^ni All ooal (anthracite only) larger than broken coal, or, when co^ is mXlumps larger than this size. (2) In soft coal, all poai nassing over the nut-coal screen. . Lute.— An adhesive clay used either to protect any iron vessel from too strong a heat or for securing air- and gas-tight joints. Lye (English).— A siding or turnout. Marhote ( Mexican). — A stake or permanent bench mark fixed in an under- M ground working, from which the length and progress thereof is measured. _ Magidr^ (Spanish) .—Roasted copper pyrites, copper sulphate, etc., used to reduce silver ores. the north end of the magnetic Ma™eMc%eridian.-The line or great circle in which the magnetic needle m i»%ad a -a'h^ V prin?ipal‘ haulage road of a mine from which the several crossroads lead to the working face. IT g&SfSSW hSgt the rope that draws the loaded cars MakU^as (North of Englandl.-Small coal produced in kirving. Fines. MaSte (Mexican).— A Horse Whim; now extended to any hoisting machine used in mines. KT-in^ and supervision of a mine, both Man^Er^ncs— An°apparatus consisting of one or two reciprocating rods, to which suitable stages are attached, used for lowering and raising men A^^ tTelXof a gangway, tunnel, or slope * (2) A hole in cylindrical boilers through which a man can get into the boiler to examine and repair it. which ore or waste Maufeo a ( Mexican) .-The act of hoisting ore or waste from a mine. MSaj/ M -AX2ll^a|eufeFS\ traveling way for the miner, and also often used as an airway or chute, or both. fScaXTo U work “re for its owner on shares or for a money payment. Marco (Mexican).— A weight of 8 oz. tapered round iron, used in splicing ropes. j Marmajas (Spanish). — Concentrated sulphides. mZZrLamp- ‘“'type of safety lamp whose chief characteristic is the lKorsh U fito?— Cffn often used synonymously with Firedamp (see page 348). Match.— (1) A charge of gunpowder put into a paper several inches long, and used for igniting explosives. (2) The touch end of a squib. >faffe S — A compound of iron and other metals, chiefly copper, with sulphur, formed during smelting. , _ ,. . Mattock— A kind of pick with broad ends for digging. MaundHl^A pick with two shanks and points, used for getting coal, etc. Mazo (Mexican). — A stamp. Mear (Derbyshire). — 32 yd. along the vein. Measures— Strata. Mecha (Mexican).— A wick for a lamp or candle, a torch. Merced (Mexican).— A gift, grant, or concession. Meridian.— A north and south line, either true or approximate. 598 Met GLOSSARY ; Mou Metal.— {1) In coal mining, indurated clay or slate. (2) An element that forms a base by combining with oxygen that is solid at ordinary tem- perature (with exception of quicksilver), opaque (except in the thinnest possible films), has a metallic luster, and is a good conductor of heat and electricity, and, as a rule, of a higher specific gravity than the non- metals. (3) (Mexican) All kinds of metalliferous minerals are called “ metal” in Mexico. Metal de Ayuda.— Fluxing ore of any kind. Metal de Cebo. — Very rich ore, usually treated in small reverberatory furnaces. Metal Ordinario— Common ore. Metal Pepena.— The best class of selected ore. Metlapil (Mexican).— See Mano. Mill. — Works for crushing and amalgamating gold and silver ores. Mill Cinder.— The slag from the puddling furnace of a rolling mill. Mill Hole.— An auxiliary shaft connecting a stope or other excavation with the level below. Mill Run.— The test of a given quantity of ore by actual treatment in a mill. Mine.— A ny excavation made for the extraction of minerals. Miner.— One who mines. a Mineral— Any constituent of the earth’s crust that has a definite com- position. Mineral Oil.— Petroleum obtained from the earth, and its distillates. Minero (Mexican).— A mine owner; a mining captain; an underground boss. Mine Road.— Any mine track used for general haulage. Mine Run— The entire unscreened output of a mine. Minero Mayor (Mexican).— The head mining captain. A mining workman is called Operario. Miners' Dial.— An instrument used in surveying underground workings. Miners' Inch.— A measure of water varying in different districts, being the quantity of water that passes through a slit 1 in. high, of a certain width under a given head (see page 136). Miner's Right.— An annual permit from the Government to occupy and work mineral land. . _ V. - , Mining— In its broad sense, it embraces all that is concerned with the extraction of minerals and their complete utilization. Mining Engineer —A man having knowledge and experience in the many departments of mining. , . , A , , Mining Retreating.— A process of mining by which the vein is untouched until after all the gangways, etc. are driven, when the mineral extraction begins at the boundarv and progresses toward the shaft. Mistress (North of England).— A miner’s lamp. Mock Lead (Cornish).— Zinc blende. Mogrollo (Mexican).— Same as Metal de Cebo. . „ „ Moil— A short length of steel rod tapered to a point, used for cutting hitches, etc. . „ , . , . Molonque (Mexican).— A rich specimen of which one-half or more is native silver. Monitor. — See Gunboat. Monkey.— The hammer or ram of a pile driver. Monkey Drift.— A small drift driven in for prospecting purposes, or a crosscut driven to an airway above the gangway. Monkey Gangway.— A small gangway parallel with the mam gangway. Monkey Rolls.—' The smaller rolls in an anthracite breaker. Monkey Shaft.— A shaft rising from a lower to a higher level. Monoclinal— Applied to an area in which the rocks all dip m the same Mop— Some material surrounding a drill in the form of a disk, to prevent water from splashing up. ,, Mortar. — The vessel in which ore is placed to be pulverized by a pestle. Mortise. — A hQle cut in one piece of timber, etc. to receive the tenon that projects from another piece. .... , . Mote (Moat).— A straw filled with gunpowder, for igniting a shot. Mother Gate.— The main road of a district in longwall working. Mother Lode (Main Lode).— The principal vein of any district. , Motive Column.— The length of a column of air whose weight is equal to the difference in weight of like columns of air in downcast and upcast shafts. The ventilating pressure in furnace ventilation is measured by the differ- ence of the weights of the air columns in the two shafts. Mouth . — The top of a shaft or slope, or the entrance to a drift or tunnel. Moy GLOSSARY Ope 599 sharp steel point, for driving into clefts when Moyle.— An iron with a levering off rock. . _ Muckle.— Soft clay overlying or underlying coal. Mucks (Staffordshire).— Bad earthy coal. ^ , Muescas (Mexican).— Notches in a stick; mortises; notches cut in a round or square beam, for the purpose of using it as a ladder. Mueseler Lamp.— A type of safety lamp invented and used m the collieries of Belgium. Its chief characteristic is the inner sheet-iron chimney for increasing the draft of the lamp. Muffle. — A thin clay oven heated from the outside. Muller— The upper grinding iron or rubbing shoe of amalgamating T3RHS otc Mullock.— Country rock and worthless minerals taken from a mine. Mundic — Iron pyrites. Naked Light.— A candle or any form cf lamp that is not a safety lamp. Narrow Work.—{ 1) All work for which a price per yard of length driven is paid, and which, therefore, must be measured. (2) Headings, chutes, crosscuts, gangways, etc. Natas (Mexican) —Same as Escoma or Grasa. Native Metal.— A metal found naturally, in that state. Natural Ventilation.— Ventilation of a mine without either furnace or otner artificial means; the heat imparted to the air by the strata, men, animals, and lights in the mine, causing it to flow in one direction, or to ascend. • Neck. — A cylindrical body of rock differing from the country around it. Needle— (1) A sharp-pointed metal rod with which a small hole is made througn the stemming to the cartridge in blasting operations. (2) A hitch cut in the side rock to receive the end of a timber. Negrillo (Mexican).— Black sulphide of silver. Nick. — To cut or shear coal after holing. , fo . Nicking— (1) A vertical cutting or shearing up one side of a face of coal. (2) The chipping of the coal along the rib of an entry or room which is usually the first indications of a squeeze. Night Shift.—’ The set of men that work during the night. Nip —When the roof and floor of a coal seam come close together, pinching the coal between them. ... . . , • Nip Out. — The disappearance of a coal seam by the thickening of the adjoin- ing strata, which takes its place. Nitro.—A corrupted abbreviation for nitroglycerine or dynamite. Nittings. — Refuse of good ore. Nodular. — Blistered or kidney-shaped ore. . Nodules.— Concretions that are frequently found to enclose organic remains. Nogs _ Logs of wood piled one on another to support the roof. See Chock. Nook —The corner of a working place made by the face with one side. Noria (Spanish). — An endless chain of buckets. . . Nozzle. — The front nose piece of bellows of a blast pipe for a furnace, or of a w'ater pipe. Nugget.— A natural lump of gold or other metal, applied to any size above 2 to 3 dwt. , . . . Nut Coal — A contraction of the term chestnut coal. Nuts. — Small lumps of coal that will pass through a screen or bars, the spaces between which vary in width from £ to 2£ in. Ocote (Mexican). — Pitch pine. _ . . Odd Work. — Work other than that done by contract, such as repairing roads, constructing stoppings, dams, etc. * _ Offtake —The raised portion of an upcast shaft ^bove the surface, for carrying off smoke and steam, etc., produced by the furnaces and engines under- Oil IS!— Shale containing such a proportion of hydrocarbons as to be capable of yielding mineral oil on slow distillation. Oil Smellers.— Men that profess to be able to indicate where petroleum oil is to be found. Old Man. — Old workings in a mine. . ... .. „„„ ~ Oolitic.— A structure peculiar to certain rocks, resembling the roe of a fish. Open Cast— Workings having no roof. 600 Ope GLOSSARY. Pan Open Cutting— (1) An excavation made on the surface for the purpose of get* ting a face wherein a tunnel can be driven. (2) Any surface excavation Openings , An Opening— Any excavation on a coal or ore bed, or to reach the same; a mine. * Openwork— An open cut. Operario ( Mexican ) .—A working miner. Operator — The individual or company actually working a colliery. Ore— A mineral of sufficient value (as to quality and quantity), to be mined with profit. . , , ^ Ores .—Minerals or mineral masses from which metals or metallic combina- tions can be extracted on a large scale in an economic manner. Ore Shoot— A large and usually rich aggregation of mineral in a vein. Distinguished from pay streak in that it is a more or less vertical zone or chimney of rich vein matter extending from wall to wall, and having a definite width laterally. Oro (Spanish).— Gold. , . % . . . Oroche (Spanish).— (1) Retorted bullion. (2) (Mexican) Bullion containing gold and silver. A . A . . _ _ _ Outburst —A blower. A sudden emission of large quantities of occluded gas. Outbye. — In the direction of the shaft or slope bottom, or toward the outside. Outcrop. — The portion of a vein or bed, or any stratum appearing at the sur- face, or occurring immediately below the soil or diluvial drift. Outcropping.— See Cropping Out. . Outlet.— A passage furnishing an outlet for air, for the miners, for water, or for the mineral mined. , , , , , , . _ Output.— The product of a mine sent to market, or the total product of a mine. Outset.—' The walling of shafts built up above the original level of the ground. Outstroke Rent.— The rent that the owner of a royalty receives on coal brought into his royalty from adjacent properties. . _ , . Outtake — The passage by which the ventilating current is taken out of the mine; the upcast. Overburden.— The covering of rock, earth, etc. overlying a mineral deposit that must be removed before effective work can be performed. Overcast.— A passage through which the ventilating current is conveyed over a gangway or airway. , „ „ A . Overhand Stoping— The ordinary method of stopmg upwards. Overlap Fault— A fault in which the shifted strata double back over them- SG1VGS. Overman— One who has charge of the workings while the men are in the mine. He takes his orders from the Underviewer. Overwind.—' To hoist the cage into or over the top of the head-frame. Oyamel (Mexican).— White pine. Pack. — A rough wall or block of coal or stone built up to support the roof. Packing. — The material placed in stuffingboxes, etc. to prevent leaks. Pack Wall— A wall of stone or rubbish built on either side of a mine road, *o carry the roof and keep the sides up. Pacos (Spanish).— Ferruginous silver ores. . ... Paddock. -( 1) An excavation made for procuring wash dirt in shallow ground. (2) A place built near the mouth of a shaft where ore is stored. Paint Gold.— The very finest films of gold coating other minerals. Paleozoic— The oldest series of rocks in which fossils of animals occur. Palero (Mexican). — A mine carpenter. „ ^ , , ,, Palm.— A piece of stout leather fitting the palm of the hand, and secured by a loop to the thumb; this has a flat indented plate for forcing the needle. Palm Needle.— A straight triangular-sectioned needle, used for sewing canvas. Palo (Mexican).— A stick; a piece of timber Pan— A thin sheet-iron dish;16 in. across the top, and 10 in. at the bottom, used for panning gold. Panel— ( 1) A large rectangular block or pillar of coal measuring, say, 130 by 100 yd. (2) A group of breasts or rooms separated from the other workings by large pillars. . . ... Panel Working.— A system of working coal seams m which the colliery is divided up into large squares or panels, isolated or surrounded by solid ribs of coal, in each of which a separate set of breasts and pillars is worked, and the ventilation is kept distinct, that is, every panel has its own circulation, the air of one not passing into the adjoining one, but being carried direct to the main return airway. Pan GLOSSARY Pic 601 Panino (Mexican).— 1 The peculiar appearance, form, or manner in which the metalliferous minerals present themselves m any given distnc Panning ot’ P anning Off.- Separating gold or tin from its accompanying minerals by washing off the latter in a pan. a chattering noise ’ “s t" n a g c a eS nart 5 the ores in place of wages. Usually, the mine owner provides handles nowder and steel, and keeps the drills sharpened, and receive*, in navment of royalty and supplies, two-thirds or more of the ore taken ^This contract is renewed weekly or monthly, etc., and the proper - Son ofoSe retained by the miners is more or less, according to the richness of The stoves ^whlreUey wSrk This is a cheap way of getting ore as far as ^labor^^c^neemed. But the miners must be constantly watched; otherwise they will leave the mine in bad state. The proportion of ore £3 to the Miners is generally bought from them by the mine Parting!— (1 ^Any ’ toto “SK' bed of earthy material. (2) A side track or turnout in a haulage road. down ore to a lower level (21 A pas^ge left irSd workings for men to travel in from one level to PasSfy — A siding in which cars pass one another underground. A turnout Pass- Into. — Wh en one mineral gradually passes into another without any PaMpZl-imlu coal mixed with 8 to 10jt of pitch or tar, and compressed Patofe^ta^-A^fato to which a patent right has been secured from the i government, by compliance with the laws relating to such claims. Afent Survey. — An^ accurate survey of a claim fj h ? t o^e cllim 7 required by law m order to secure a patent right to the claim. Pa(*WMerfcan) fl -Aiay paved enclosure more or less surrounded by build- toga ^ av ^ A floor Qr yard where argentlfer ous mud is treated by amalgamation. ZJrt . — That portion of an alluvial deposit that contains gold in payable quantities. Pay Out.— To slacken or let out rope. Pay Rock — Mineralized rock. Pay Streak— Mineralized part of rock. Pea C Coal.—l smalTsize o^nthracite coal (see page 434). Peat — T^decomposed partly carbonized organic matter ofbogs, swamps, eta Pebble Jack.- Zinc blende in small crystals or pebble-like forms is not attached to rock, but is found m clay openings m the rock. Pee (Derbyshire).— A fragment of lead ore. Pdla , or Plata Pella (Mexican).— Silver amalgam. P^tHo'ji- -A^odfn covering for the protection of sinkers working in a PerJice — A*few pieces of timber laid as a roof over men’s heads, to screen them when working in dangerous places, e.g., at the bottom of shafts. Pepenado ( Spanish ) .—Dressed ore. P^ZZonTabU^r-kintof jolting table used in separating very tine ores from slimes. . . , fSVi-To^ “tonally decrease in thickness. Petlanque (Mexican).— Ruby silver. Petrifaction — Organic remains converted into stone. - i) a tooffor cutting and holing coal. (2) To dress the sides Ox face of an excavation with a pick. 602 Pic GLOSSARY. Pla Picker.— { 1) A small tool used to pull up the wick of a miner’s lamp. (2) A person who picks the slate from the coal in an anthracite-coal breaker. Picking Chute. — A chute in an anthracite breaker along which boys are stationed to pick the slate from coal. Picking Table— (1) A flat or slightly inclined platform on which anthracite coal is run to be picked free from slate. (2) A sorting table. Pico (Mexican). — A striking or sledge hammer. Picture. — A screen to keep off falling water from men at work. Piedras de Mano (Mexican). — Hand specimens. Pig— A piece of lead or iron cast into a long iron mold. Pigsty Timbering. — Hollow pillows built up of logs of wood laid crosswise for supporting heavy weights. Pike. — A pick. Pilar (Mexican). — A pillar of rock or ore left to sustain some portion of the mine. Pileta (Mexican).— (1) A sump. (2) The basin or pot where melted metal is collected. Piling.— Long pieces of timber driven into soft ground for the purpose of securing a solid base on which to build any superstructure. Pillar. — (1) A solid block of coal, etc. varying in area from a few square yards to several acres. (2) Sometimes applied to a single timber support. Pillar -and-Room — A system of working coal by which solid blocks of coal are left on either side of the rooms, entries, etc. to support the roof until the rooms are driven up, after which they are drawn out. Pillar-and-Stall. — See Breast-and-Pillar . Pillar Roads— Working roads or inclines in pillars having a range of long- wall faces on either side. Pillion ( Cornish) .—Metal remaining in slag. Pina (Mexican).— Same as Pella. Pinch. — A contraction in the vein. Pinch Out. — When a lode runs out to nothing. Pinta (Mexican).— The color, weight, grain, etc. of ores, whereby it is pos- sible to form some idea of their richness in the various metals. Pipe— An elongated body of mineral. Also the name given to the fossil trunks of trees found in coal veins. Pipe Clay.— A soft white clay. Piped Air. — Air carried into the working place by pipes or brattices. Piping— Undercutting and washing away gravel before the water nozzle. Pit.—( 1) A shaft. (2) The underground portion of a colliery, including all workings. (3) A gravel pit. Pit Bank.— The raised ground or platform where the coal is sorted and screened at the surface. Pit Bottom.— The portion of a mine immediately around the bottom of a shaft or slope. See Shaft Bottom. (1; Rise of a seam. (2) Grade of an incline. (3) Inclination. (Cor- ’'ish) A part of a lode let out to be worked on shares, or by the piece. Pit Coal. — Generally signifies the bituminous varieties of coal. Pit Frame.— See Head-Frame. Pit Headman— The man who has charge at the top of the shaft or slope. Pitman. — A miner; also, one who looks after the pumps, etc. Pit Prop.— A piece of timber used as a temporary support for the roof. Pit Rails. — Mine rails for underground roads. Pit Room.— The extent of underground workings in use or available for use. Pit's Eye. — Pit bottom or entrance into a shaft. Pit Top. — The mouth of a shaft or slope. Place. — The portion of coal face allotted to a hewer is spoken of as his “working place,” or simply “place.” Placer. — A surface accumulation of mineral in the wash of streams. Placer Mining. — Surface mining for gold where there is but little depth of alluvial. Plan.— (1) The system on which a colliery is worked as Longwall, Pillar- and-Breast , etc. (2) A map or plan of the colliery showing outside improvements and underground workings. (3) (Mexican) The very lowest working in a mine. Trabajar de Plan.— To work to gain depth. Plancha —A pig of lead, etc. A plate, thick sheet, or mass of any meta Pla GLOSSARY. Pop 603 Planchera (Mexican).— A mold of sand, earth, or iron, to form pigs of lead. , , . . . . . , Plane— A main road, either level or inclined, along which coal is conveyed by engine power or gravity. Plane Table — A simple surveying instrument by means of which one can plot on the field. , , x ... Planilla (Mexican).— An inclined plane of mason work, wood, etc., on which tailings are spread out, to be concentrated by jets of water, skilfully applied. Planillero (Mexican).— A workman who devotes himself to concentrating tailings, etc. on the Planillas; always paid by weight, measure, or con- centrates produced. . . , _ . Plank Dam.— A water-tight stopping fixed m a heading constructed of timber placed across the passage, one upon another, sidewise, and tightly wedged. „ , , . _ Plank Tubbing— Shaft lining of planks driven down vertically behind wooden cribs all around the shaft, all joints being tightly wedged, to keep back the water. Plant .— The shafts or slope, tunnels, engine houses, railways, machinery, workshops, etc. of a colliery or other mine. Plat , or Map— A map of the surface and underground workings, or of either, to draw such a map from survey. Plata ( Spanish ) .—Silver. Plata Blanca (Mexican).— Native silver. Plata Cornea Amarillia (Spanish).— Iodyrite. Plata Cornea Blanca (Spanish).— Cerargy rite. Plata Cornea Verde (Spanish).— Embolite. Plata Mixta (Spanish).— Gold and silver alloy. Plata Negra (Spanish).— Argentite. Plata Pasta (Spanish).— Spongy silver bars after retorting. Plata Piha (Spanish).— Silver after retorting. Plata Verde (Spanish) .— Bromyrite. Plate (North of England).— Scaly shale in limestone beds. Plates— Metal rails 4 ft. long. Plenum— A mode of ventilating a mine or a heading by forcing fresh air J.I/. Plomada (Mexican).— A plumb-line or plumb-bob. Plomb d' Oeuvre (French).— Dressed galena. Plomillos (Mexican).— Shots of lead found in slags. Plomo (Spanish).— Lead, galena. , , Plugging— When drift water forces its way through the puddle clay into the shaft, holes are bored through the slabs near the leakage point, and plugs of clay forced into them until the leakage is stopped. Plumb ^ j 0^1(33,1 Plummet.— (1) A heavy weight attached to a string or fine copper wire used for determining the verticality of shaft timbering. (2) A plumb-bob for setting a surveying instrument over a point. Plunger— The solid ram of a force pump working in the plunger case. Plunger Case .— The pump cylinder or barrel in which the plunger works. Plush Copper.— Chalcotrichite. Plwm (Welsh). — Lead. Poblar (Mexican).— To set men at work in a mine. Pocket .— (1) A thickening out of a seam of coal or other mineral over a small area. (2) A hopper-shaped receptacle from which coal or ore is loaded into cars or boats. ' Podar (Cornish).— Copper pyrites. , . Pole Tools . — Drilling tools used in drilling in the old fashion with rods, now superseded by the rope-drilling method. Polroz (Cornish).— Waterwheel pit. Poling . — Refining metal, when in a molten condition, by stirring it up with a green pole of wood. Poll Pick . — A pick having the longer end pointed and the shorter ena tiam- mer-shaped. Polvillos (Spanish).— Rich ores or concentrates. Polvoulla (Spanish).— Black silver. Poppet Heads .— The pulley frame or hoisting gear over a shaft. Poppet {Puppet).— (1) A pulley frame or the head-gear oyer a sliait. (2) A valve that lifts bodily from its seat instead of being hinged. GLOSSARY. Pun 004 Pos Post _(1) Any upright timber; applied particularly to the timbers used for propping. See Prop. (2) Local term for sandstone. Post stone may be “strong,” “ framey,” “ short,” or “ broken.” Post-and-Stall. — A system of working coal much the same as Pillar-and-Stall. Post Ternary.— Strata younger than the Tertiary formation. Pot Bottom. — A large boulder in the roof slate, having the appearance of the rounded bottom of a pot, and which easily becomes detached. Pot Growan (Cornish).— Decomposed granite. . Pot Hole —A circular hole in the rock caused by the action of stones whirled around by the water when the strata was covered by water. They are generally filled with sand and drift. . . Power Drill— A rock drill employing steam, air, or electricity as a motor. Prian (Cornish). — Soft white clay. , , . ' . . Pricker— ( 1) A thin brass rod for making a hole m the stemming when blasting, for the insertion of a fuse. (2) A piece of bent wire by which the size of the flame in a safety lamp is regulated without removing the top of the lamp. x A _ , _ , . p r iU — (l) An extra-rich stone of ore. (2) A bead of metal. Prong (English).— The forked end of the bucket-pump rods for attachment to the traveling valve and seat. _ A . . Prop.— A wooden or cast-iron temporary support for the root. Propping. — The timbering of a mine. , , Prospect —The name given to underground workings whose value has not yet been made manifest. A prospect is to a mine what mineral is to ore. Prospect Hole— Any shaft or drift hole put down for the purpose of prospect- ing the ground. , _ , Prospect Tunnel or Entry— A tunnel or entry driven through barren measures or a fault to ascertain the character of strata beyond. Prospecting.— Examining a tract of country in search ol minerals. Prospector— One engaged in searching for minerals. Protector Lamp— A safety lamp whose flame cannot be exposed to the out- ward atmosphere, as the action of opening the lamp extinguishes the Prove ?— (1) To ascertain, by boring, driving, etc., the position and character of a coal seam, a fault, etc. (2) To examine a mine m search of fire- damp, etc., known as “ proving the pit.” Proving Hole.—{ 1) A bore hole driven for prospecting purposes. (2) A small heading driven in to find a bed or vein lost by a dislocation of the strata, or to prove the quality of the mineral in advance of the other workings. Pudding Machine— A circular machine for washing pay dirt. Pudding Rock.— Conglomerate. , . . , . Puddle.— (1) Earth well rammed into a trench, etc., to prevent leaking. (2) A process for converting cast iron into wrought iron. Pueble (Mexican).— The actual working of a mine; the aggregation ot persons employed therein. . * T . Puertas (Mexican).— Massive barren rocks, or “ horses,” occurring m a vein. Pug Mill.— A mill for preparing clay for bricks, pottery, etc. Pulley.— { 1) The wheel over which a winding rope passes at the top ot the head-gear. (2) Small wooden cylinders over which a winding rope is carried on the floor or sides of a plane. . ... „ Pulleying . — Overwinding or drawing up a cage into the pulley trame. Pulp.— Crushed ore, wet or dry. Pump— Any mechanism for raising water. Purnp Ring —A fiat iron ring that, when lapped with tarred baize or engine shag, secures the joints of water columns. . . Pump Rods. — Heavy timbers by which the motion of the engine is trans- mitted to the pump. In Cornish and bull pumps, the weight of the rods makes the effective (pumping) stroke, the engine merely lifting the rods on the up stroke. Pump Slope. — A slope used for pumping machinery. to Pump Station.— An enlargement made in the shaft, slope, or gangway, to Pump C Tree. -Cast-iron pipes, generally 9 ft. long, of which the column or set is formed. , . . . Punch-and- Thirl. — A kind of pillar-and-stall system of working. Pun GLOSSARY. Ree 605 Punch Prop— A short timber prop set on the top of a crown tree, or used in Put^Stonfs.- !oft P pfeces of decomposed rock found in placer deposits. Pyran (Cornish).— See Prian. Pyrites— Sulphide of iron. . . , . , . Pyrometer— An instrument for measuring high degrees of heat. Marty — ftT-An ^op^^rllce 0 excavation for working valuable rocks or minerals. (2) An underground excavation for obtaining stone for stowage or pack walls. Quartz Bucket— A bucket for hoisting quartz. ^emadero ’ ( T^xfcmi ) !— A burning place; a retorting furnace for silver or Qaem^dos '(MeScan ) .—Burnt stuff. Any dark cinder-like mineral encoun- H tered in a vein or mineral deposit, generally mangamferous. Queme (Mexican) .-A roast of ore; the process of roasting ore, Quick (Adjective).— Soft, running ground; an ore or pay streak is said to be Quickening when the associated minerals indicate richer mineral ahead. Quick (Noun).— (1) Productive. (2) Mercury Quicksand. — Soft watery strata easily moved, or readily yielding to pressure. Quicksilver. — Mercury . ^itapepena^ Mexican^— A watchman that searches the miners as they come out at the mouth of a mine. Rabban (Cornish).— Yellow dry gossan. Rabbling. — Stirring up a charge of ore in a reverberatory furnace wit* specially designed iron rods. „ , .. Race — A channel for conducting water to or from the piace where it pei' forms work. The former is termed the headrace, and the latter tiu tailrace. . _ Rack (Cornish).— A stationary buddle. . . Paff.—The coarse ore after crushing by Cornish rolls. Rat a Wheel°—A revolving wheel with side buckets for elevating the raff. Rafter Timbering.— That in which the timbers appear like roof rafters. Rag Burning (Cornish).— The first roasting of tin-witts. Rag-Wheel— Sprocket wheel. A wheel with teeth or pins that catch into th e links of chains. „ , A .. , Rails —The iron or steel portion of the tramway or railroad. . Rake (Cornish).— (1) A vein. (2) (Derbyshire) Fissure vein crossing strata. Pam —(1) The plunger of a pump. (2) A device for raising water. Ramal (Mexican). — A branch vein. . . Ramalear (Mexican). — To branch off into various divisions. Ramble.— Stone of little coherence above a seam that falls readily on tne removal of the coal. See Following Stone. Rcmwr -—A iewev with a hammer attached at one end, which signals by striking a plate of metal, when the signaling wire to which it is attached Pash —A term used to designate the bottom of a mine when soft and slaty. Rastrillo (Mexican).— A rake; a stirrer for moving ore in a furnace. Rastron (Mexican).— A Chilian mill. Raw Ore— Not roasted or calcined. Reacher. — A slim prop reaching from one wall to the other. Reamer. — An enlarging tool. Reaming. — Enlarging the diameter of a bore hole. . . . . Receiving Pit— A shallow pit for containing material run into it. Red-Ash CM— Coal that produces a reddish ash, when burnt. Red Rab (Cornish).— Red slaty rock. . . .. . ., - Reduced— When a metal is freed from its chemical associate it is said to be reduced to the metallic state. . Reduction Works— Works for reducing metals from their ores. Peef.—i l) A vein of quartz. (2) Bed rock of alluvial claims. Reef Drive.— In alluvial mines, drives made in the country rock or reef. 606 Ref GLOSSARY. ' Riv Refining.— The freeing of metals from impurities. Refractory.— Rebellious ore, not easily treated by ordinary processes. Refuge Hole.— A. place formed in the side of an underground plane in which a man can take refuge during the passing of a train, or when shots are fired. Regulator.— A door in a mine, the opening or shutting of which regulates the supply of ventilation to a district of the mine. Regulus. — See Matte. Relampago , or Relampaguear (Mexican).— The brightening of the silver button during cupellation. Reliz (Spanish).— Wall of lode. Rendir (Mexican).— Is when all the silver has been amalgamated in a heap of argentiferous mud on a patio. Rendrock.— A variety of dynamite. Repairman— A workman whose duty it is to repair tracks, doors, brattices, or to reset timbers, etc., under the direction of the foreman. Repaso-Repasar (Mexican) .—The art of mixing up the mud heaps in the patio process of amalgamation by treading them over with horses or mules. Repos Adero (Mexican).— The bottom of a crucible or pot in an upright smelting furnace. Rescatadores (Mexican).— Ore buyers. .Reserve.— Mineral already opened up by shafts, winzes, levels, etc., which mav be broken at short notice for any emergency. Reservoir— An artificially built, dammed, or excavated place for holding a reserve of water. Respaldos (Mexican).— The walls enclosing a vein. Respdldo Alto.— The hanging wall. Respaldo Bajo. — The foot-wall. Rests, Keeps, Wings.— Supports on which a cage rests when the loaded car is being taken off and the empty one put on. Resue See Stripping . Retort— (1) A vessel with a long neck, used for distilling the quicksilver from amalgam. (2) The vessel used in distilling zinc. Return.— The air-course along which the vitiated air of a mine is returned or conducted back to the upcast shaft. Return Air.— The air that has been passed through the workings. Reverberatory.— A class of furnaces in which the flame from the fire-grate is made to beat down on the charge in the body of the furnace. Reversed Fault— See Overlap Fault. Rib.— The side of a pillar. Rib-and-Pillar.—A system of working similar to Pillar-and-Stall. Ribbon.— A line of bedding or a thin bed appearing on the cleavage surface and sometimes of a different color. Rick.— Open heap in which coal is coked. Ridding. — Clearing away fallen stone and debris. Riddle.— An oblong frame holding iron bars parallel to each other, used for sifting material that is thrown against it. Ride, Riding.— To be conveyed on a cage or mine car. Rider.— (1) A guide frame for steadying a sinking bucket. (2) Boys that ride on trips on mechanical haulage roads. (3) A thin seam of coal overlying a thicker one. Riffle, or Ripple.— Crosspieces placed on the bottom of a sluice to save gold; or grooves cut across inclined tables. Right Shore— The right shore of a river is on the right hand when descend- ing the river. Rill.— The coarse ore at the periphery of a pile. Rim Rock.— Bed rock forming a boundary to gravel deposit. Ring.—{1) A complete circle of tubbing plates placed round a circular shaft. (2) Troughs placed in shafts to catch the falling water, and so arranged as to convey it to a certain point. Ripping. — Removing stone from its natural position above the seam. Riscos (Mexican).— Sharp and precipitous rocks; amorphous quartz found in veins or outcrops. . Rise.— The inclination of the strata, when looking up the pitch. Rise Workings.— Underground workings carried on to the rise or high side of the shaft. River Mining.— Working beds of existing rivers by deflecting their course or by dredging. Roa GLOSSARY ; Saf 607 Road.—( 1) Any underground passageway or gallery. (2) The iron rails, etc. of underground roads. Roasting— Heating ores at a temperature sufficient to cause a chemical change, but not enough to smelt them. Rob.— To cut away or reduce the size of pillars of coal. Robbing .—' The taking of mineral from pillars. Robbing an Entry— See Drawing an Entry. Rock— A mixture of different minerals in varying proportions. Rock Breaker —A machine for reducing ore in size by crunching it between powerful jaws. Rock Chute.— See Slate Chute. Rock Drill— A rock-boring machine worked by hand, compressed air, steam, or electrical power. Rocker . — See Cradle. Rock Fault— A replacement of a coal seam over greater or less area, by some other rock, usually sandstone. Rodding — The operation of fixing or repairing wooden eye guides in shafts. Roll— An inequality in the roof or floor of a mine. Roller.— A small steel, iron, or wooden wheel or cylinder upon which the hauling rope is carried just above the floor. Rolleyway . — A main haulage road. Rolling Ground — When the surface is much varied by many small hills and valleys. Rolls -Cast-iron cylinders, either plain or fitted with steel teeth, used to break coal and other materials into various sizes. Roof .— The top of any subterranean passage. Room . — Synonymous with Breast. Room-and-Rance — A system of working coal similar to Pillar-and-Stall. Rope Roll— The drum of a winding engine. Rosiclara (Spanish).— Ruby silver ore. Roughs (Cornish).— Second quality tin sands. Round Coal .— Coal in large lumps, either hand-picked, or, after passing over screens, to take out the small. Royalty .— The price paid per ton to the owner of mineral land-by the lessee. Rubbing Surface .— The total area of a given length of airway; that is, the area of top, bottom, and sides added together, or the perimeter multi- plied by the length. Rubble .— Coarse pieces of rock. Rumbo (Mexican).— The course or direction of a vein. Run. — (1) The sliding and crushing of pillars of coal. (2) The length of a lease or tract on the strike of the seam. Run Coal.—Soit bituminous coal. Rung , Rundle , or Round— A step or cross-bar of a ladder. Runner.— A man or boy whose duty it is to run mine cars by gravity from working places to the gangway. Running Lift.— A sinking set of pumps constructed to lengthen or shorten at will, by means of a sliding or telescoping wind bore. Rush— An old-fashioned way of exploding blasts by filling a hollow stalk with slow powder and then igniting it. Rush Gold.—G old coated with oxide of iron or manganese. Rush Together.— See Caved In. Rusty— Stained by iron oxide. Saca (Mexican).— A bagful of ore. A mine is said to be de buena saca when it has large quantities of ore easy to get out. Saddle .—An anticlinal, a hogback. Saddleback —A depression in the strata. See Roll. Saddle Reef . — A reef having the form of an- inverted V. Safety Cage.— A cage fitted with an apparatus for arresting its motion in the shaft in case the rope breaks. Safety Car . — See Barney. Safety Catches .— Appliances fitted to cages, to make them safety cages. Safety Door . — A strongly constructed door, hinged to the roof, and always kept open and hung near to the main door, for immediate use. when main door is damaged by an explosion or otherwise. Safety Fuse— A cord with slow-burning powder in the center for exploding charged blast holes. 608 Saf GLOSSARY. Seg Safety Lamp— A miner’s lamp in which the flame is protected in such a manner that an explosive mixture of air and firedamp can be detected by the mixture burning inside the gauze. Sag— A depression, e.g., in ropes, ranges of mountains, etc. Sagre, or Seggar.—A local term for fireclay, often forming the floor (or thill,) of coal seams. _ . Salting.— (1) Changing the value of the ore m a mine or of ore samples before they have been assayed, so that the assay will show much higher values than it should. (2) Sprinkling salt on the floors of underground passages in very dry mines, in order to lay the dust. Sampler.— (1) An instrument or apparatus for taking samples. (2) One whose duty it is to select the samples for an assay, or to prepare the mineral to be assayed, by grinding and sampling. . . . , . . , Sampling Wor ks.— Works for sampling and determining the values obtained in ores; where ores are bought and sold. Samson Post.— An upright supporting the working beam that communicates oscillatory motion to pump or drill rod. Sand Bag— A bag filled with sand for preventing a washout by obstructing Sand^ Pump. ‘—A sludger; a cylinder provided with a stem (or other) valve, lowered into a drill hole to remove the pulverized rock. Scaffolding. — Incrustations on the inside of a blast furnace. Scale. — (1) A small portion of the ventilating current in a mine passing through a certain size of aperture. (2) The rate of wages to be paid, which varies under certain contingencies. Scale Door. — See Regulator. . Scallop —To hew coal without kirving or nuking or shot firing. Schist — Crystalline or metamorphic rocks having a slaty structure. Scissors Fault— A fault of dislocation, in which two beds are thrown so as to cross each other. , Scoop— A large-sized shovel with a scoop-shaped blade. Scoria. — Ashes. Scorifier.— A small dish used in assaying. Scovan (Cornish).— A tin lode showing no gossan at surface. Scove (Cornish).— Purest tin ore. „ ,. Scramming. — Cleaning up small bodies or patches of ore left in the ordinary Scraper.— {!) T tool ' for cleaning the dust out of the bore hole. (2) A mechanical contrivance used at colleries to scrape the culm or slack along a trough to the place of deposit. . Scrapper — A local name given to parties that pick up the ore left on dumps. Screen. — (1) A mechanical apparatus for sizing materials. (2) A cloth brat- tice or curtain hung across a road in a mine, to direct the ventilation. Serin (Derbyshire). — A small vein. . Scrowl (Cornish).— Loose ore where a vein is crossed. Sculping. — Fracturing the slate along the grain, l. e., across the cleavage. Scupper Nails.— Nails with broad heads, for nailing down canvas, etc. Sea Coal. — That which is transported by sea. • . . ^ e Sealing— Shutting off all air from a mine or a part of a mine by stoppings. Seam.—{ 1) Synonymous with Bed , Vein , etc. (2) (Cornish) A horse load Seam-Oid.— A term applied to a shot or blast that has simply blown i out a softer stratum of the deposit in which it was placed, without dislodging the other strata or layers of the seam. . Second Outlet ( Second Opening).— A passageway out of a mine, for use in case of accident to the main outlet. Seconds.— 1 The second-class ore of a mine that requires dressing. Second Working.— The operation of getting or working out the pillars .ormed Section 1 — (LtoA verticaf or horizontal exposure of strata. (2) A drawing or sketch representing the rock strata as cut by a vertical or a horizontal Sed&ntary Rocks.— Rocks formed from deposits of sediment by wind or SeeFbeup— A water-tight packing of flaxseed around the tube of a drill hole, to prevent the influx into the hole of water from above. Segregations.— Detached portions of veins in place. Sel GLOSSARY. Sho 609 Self-Acting Plane— An inclined plane upon which the weight or force of gravity acting on the full cars is sufficient to overcome the resistance of the empties; in other words, the full car, running down, pulls the other car up. Self-Detaching Hook.— A self-acting hook for setting free a hoisting rope m case of overwinding. ■ Self-Feeders— Automatic appliances for feeding ore-dressing machines. Selvage— The clay seam on the walls of veins; gouge. Separation Doors.— The main doors at or near the shaft or slope bottom, which separate the intake from the return airways. Separation Valve— A massive cast-iron plate suspended from the roof of a return airway through which all the return air of a separate district flows, allowing the air to always flow past or underneath it; but in the event of an explosion of gas, the force of the blast closes it against its frame or seating, and prevents a communication with other districts. The blast being over, the weight of the valve allows it to return ^o its normal position. Set. — To fix in place a prop or sprag. ... , Set Hammer.— The flat-faced hammer held on hot iron by a blacksmith when shaping or smoothing a surface by aid of his striker’s sledge. Set of Timber— The timbers which compose any framing, whether used in a shaft, slope, level, or gangway. Thus, the four pieces fuming a single course in the curbing of a shaft, or the three or four pieces forming the legs and collar, and sometimes the sill of an entry framing are together called a set of timber, or timber set. . Shackle.— A U-shaped link in a chain closed by a pm; when the latter is with- drawn the chain is severed at that point. Shadd (Cornish).— Rounded fragments of ore overlying a vein. Shaft.— A vertical or highly inclined pit or hole made through strata, through which the product of the mine is hoisted, and through which the ventila- tion is passed either into or out of the mine. A shaft sunk from one seam to another is called a “blind shaft.” Shaft Pillar.— Solid material left unworked beneath buildings and around the shaft, to support them against subsidence. . Shaking Table.— An inclined table for concentrating fine grains of ore, which is rapidly shaken by a short motion Shale— (1) Strictly Speaking, all argillaceous strata that split up or peel off in thin laminae. (2) A laminated and stratified sedimentary deposit of clay, often impregnated with bituminous matter. Shank.— 1 The body portion of any tool, up from its cutting edge or bit. Shearing— Cutting a vertical groove in a coal face or breast. The cutting of a “ fast end” of coal. . Shear Legs.— A high wooden frame placed over an engine or pumping shaft fitted with small pulleys and rope for lifting heavy weights. Shears , or Sheers (English).— Two tall poles, with their feet some distance apart and their tops fastened together, for supporting hoisting tackle. Shear Zone.— Hogback. Sheave— A wheel with a grooved circumference over which a rope is turned either for the transmission of power or for winding or hauling. Sheet Pump.— See Sludger , . , _ . Sheets .—Coarse cloth curtains or screens for directing the ventilating current underground. _ _ _ _ _ Shelly— A name applied to coal that has been so crushed and fractured that it easily breaks up into small pieces. The term is also applied to a lami- nated roof that sounds hollow and breaks into thin layers of slate or shale. Shet (Staffordshire). — Fallen roof of coal mine. . _ Sheth. — An old term denoting a district of about eight or nine adjacent bords. Thus, a “ sheth of bords,” or a “ sheth of pillars.” Shift— {1) The number of hours worked without change. (2) A gang or force of workmen employed at one time upon any work, as the day shift, or the night shift. Shoad (Cornish).— See Shadd. Shoading (Cornish). — Prospecting. . , Shoe. — (1) A steel or iron guide piece fixed to the ends or sides of cages, to fit or run on the conductors. (2) The upper working face of a stamp or grinding pan. (3) The lower capping of any post or pile, to protect its end while driving. (4) A wooden or sheet-iron frame or muff arranged 610 Sho GLOSSARY. Sin at the bottom of a shaft while sinking through quicksand, to prevent the inflow of sand while inserting the shaft lining. Shoot, Chute, Shute .— (1) A run of rich material in a vein. (2) An inclined or vertical trough or pipe for conveying materials from a higher to a lower level. Shoot.— 1 To break rock or coal by means of explosives. Shooting— Blasting in a mine. Shore (English).— A studdle or thrusting stay. Shore Up. — To stay, prop up, or support by braces. Shot.— (1) A charge or blast. (2) The firing of a blast. (3) Injured by a blast. Shot-Firer.— See Shot Lighter. Shot Hole— The bore hole in which an explosive substance is placed for blasting. Shot Lighter, or Shot Firer.—A man specially appointed by the manager of the mine to fire off every shot in a certain district, it, after he has examined the immediate neighborhood of the shot, he finds it free from gas, and otherwise safe. Shotty Gold— Granular pieces like shot. Show.— When the flame of a safety lamp becomes elongated or unsteady, owing to the presence of firedamp in the air, it is said to show. Showing . — The first appearance of float, indicating the approach to an out- cropping vein or seam. Blossom. Shroud.— A housing or jacket. Shute. — See Chute, Shoot, and Schute. Shutter.— (1) A movable sliding door, fitted within the outer casing of a Guibal or other closed' fan, for regulating the size of the opening from the fan, to suit the ventilation and economical working of the machine. (2) A slide covering the opening in a door or brattice, and forming a regulator for the proportionate division of the air-current between two or more districts of a mine. Sickening.— A coating of impurities on quicksilver that retards amalgama- tion or the coalescence of the globules of quicksilver. Siddle. — Inclination. Sid e .—{ 1) The more or less vertical face or wall of coal or goaf forming one side of an underground working place. (2) Rib. (3) A district. Side Chain.— A chain hooked on to the sides of cars running on an incline or along a gangway, to keep the cars together in case the coupling breaks Sidelong Reef.— An overhanging wall of bed rock in alluvial formations running parallel with the course of the gutter; generally only on one side of it. Siding— A short piece of track parallel to the mam track, to serve as a passing place. , . Siding Over.— A short road driven in a pillar in a head wise direction. Sight— (1) A bearing or angle taken with a compass or transit when making a survey. (2) Any established point of a survey. Sights . — Bobs or weighted strings hung from two or more established points in the roof of a room or entry, to give direction to the men driving the entry or room. , , . , Sill.—(1) The floor piece of a timber set, or that on which the track rests; the base of any framing or structure. (2) The floor of a seam. Silver. — (1) A certain white ductile and valuable metal. (2) Short for quick- silver. . Sing . — The noise made by a feeder of gas issuing from the coal. Singing Coal.— Coal from which gas is issuing with a hissing sound. Singing Lamp . — A safety lamp, which, when placed in an atmosphere ol explosive gas, gives out a peculiar sound or note, the strength of the note varying in proportion to the percentage of firedamp present. Single-Entry System.— A system of opening a mine by driving a single entry only, in place of a pair of entries:" The air-current returns along the face of the rooms, which must be kept open. Single-Intake Fan— A ventilating fan that takes or receives its air upon one side only. , . ... . . Single-Rope Haulage.— A system of underground haulage m which a single rope is used, the empty trip running in by gravity. This is engine-plane haulage. , . . , Sink— To excavate a shaft or slope; to bore or put down a bore hole. Sin GLOSSARY. Sli 611 Sinker.— A. man who works at the bottom of a shaft or face of a slope during the course of sinking. Sinker Bar.— In rope drilling, a heavy bar attached above the jars, to give force to the up stroke, so as to dislodge the bit in the hole. Sinking— The process of excavating a shaft or slope or boring a hole. Siphon.— A simple, effective, and economical mode of conveying water over a hill whose height is not greater than what the atmospheric pressure will raise the water. Its form is that of an iron pipe, bent like an inverted U; the vertical height between the surface of the water in the upper basin and the top of the hill is called the lift of the siphon; while the vertical height between the surfaces of the water in the upper and lower basins is called the fall of the siphon. Sizing.— To sort minerals into sizes. Skew Back.— The beveled stone from which an arch springs, and upon which it) rests Skids. — Slides upon which heavy bodies are slid from place to place. Skimpings (Cornish).— The poorest ore skimmed off the jigger. Skip .— (1) A mine car. (2) A car for hoisting out of a slbpe. (3) A thin slice taken off from a breast or pillar or rib along its entire length or part of its length. Skirting.— Road opened up or driven next a fall of stone, or an old fallen place. Skit (Cornish). — A pump. Slab.— Split pieces of timber from 2 in. to 3 in. thick, 4 ft. to 6 ft. long, an - X . ' s* . ' - -V, : V . f ¥ 3 s z i) x / ,^ X ^ 'M 4 Su ^ / y ^ 0 /X'&'t- A ^ trft A . ^ xli jLJ£ ^j\ t A* A >^f AsX»\~j /tA'-''\- ffiA**%f'- V# jhi«tf w / vi'ifi /w ^ £ / ['■ i. * I *. . Practical Promotion For Mine Employes The use of labor-saving machinery and the State mine-exam- ination laws have shaped conditions so that the only practical way for ambitious mine employes to advance is by securing theoretical technical training for the position to which they desire to attain. The surest, most practical, most thorough, cheapest, and simplest way for mine workers to gain the train- ing necessary to qualify them for the highest positions in the profession is through the Courses offered by the International Correspondence Schools, of Scranton, Pa. These Courses have been written by the best mining authorities in the country and edited into Courses of Instruction by the Schools’ own experts. They are taught by a system of cor- respondence instruction that has been tried, proved, and per- fected for 16 years, during which time it has been the means of advancing hundreds upon hundreds of ambitious miners from low-paying positions to places of responsibility and high salary. You need not leave your present work. You can study in your own home, in your spare time, and the cost is insignificant compared with the results achieved. The I. C. S. has in its curriculum 208 different Courses of Instruction covering all the leading trades and professions. The Courses especially adapted to the needs of miners are those that will fit them for positions such as the following: Mining Engineer Mine Inspector Mine Manager Mine Superintendent Mine Foreman Mine Surveyor Mine Fire Boss Metallurgist Assayer Electrical Engineer Electrician Write for special catalog on the position you desire to secure. International Correspondence Schools Drawer G, SCRANTON, PA. 1 Better Earnings For Coal Miners The I. C. S. Courses in Coal Mining have been remarkably suc- cessful in enabling coal miners to secure the knowledge of their professions in both the anthracite, and bituminous fields that has enabled them to pass State Examinations and secure higher positions and better wages. Sixteen of the Mine Inspectors of the State of Pennsylvania are I. C. S. students. Concerning these Schools, John Mitchell says: “It gives me pleasure to recommend the International Correspondence Schools, ; of Scranton, Pa. During my connection with the miners’ organiza- tion I have formed the acquaintance of a vast number of men and boys who have taken advantage of the opportunities offered by these Schools, to obtain, with little cost to themselves, a practical education that fitted them to hold lucrative and responsible positions.” . The Complete Coal Mining Course contains about 4,500 pages of instruction matter and 2,500 illustrations. The following subjects are taught: Arithmetic Formulas Logarithms Geometry and Trigonometry Geometrical Drawing Mine Surveying Properties of Gases Mine Gases Mine Ventilation Geology of Coal Examination of Coal Properties Rock Boring Rock Drilling Explosives and Blasting Drifts, Slopes, and Shafts Methods of Working Mechanics Fuels Steam and Steam Boilers Steam Engines Air Compression Elements of Electricity and Magnetism Direct-Current Dynamos and Motors We also have a Course for Mine Foremen and one for Fire Bosses. Special catalogs on any of these Courses will be sent on request. International Correspondence Schools Drawer G» SCRANTON* PA. Alternating - Current Machin- ery Operation of Dynamo-Electric Machinery Transmission, Lighting, and Signaling Coal-Cutting Machinery Trackwork Timbering Timber Trees Hoisting Haulage Hydromechanics Mine Drainage Mine Pumps Surface Arrangements at Bitu- minous Mines Surface Arrangements at An- thracite Mines Preparation of Anthracite Coal Washing Principles of Coking Coking in the Beehive Oven By-Product Coking First Aid to the Injured 2 Advancement For Metal Miners As in coal mining, the man who wishes to rise in the metal- mining profession must secure a knowledge of the theory and science of modern metal mining. A large amount of money was expended in making the I. C. S. Metal Mining Course, m many ways the most valuable source of knowledge on mining that is in existence, and it contains the results of years of study by our best mining experts. The Metal Mining Course com- prises about 2,800 pages of instruction and 1,238 illustrations. The following subjects are included: Arithmetic Formulas Geometry and Trigonometry Logarithms (Optional) Geometrical Drawing Mechanics Fuels Mine Surveying Metal-Mine Surveying Mineral-Land Surveying Steam and Steam Boilers Steam Engines Air Compression Elements of Electricity and Magnetism Direct-Current Dynamos and Motors Alternating-Current Machinery Operation of Dynamo-Electric Machinery Transmission, Lighting, and Signaling Hydromechanics Mine Pumps Hoisting Haulage Mine Drainage Rock Boring Rock Drilling Explosives and Blasting Timber Trees Gas and Oil Engines Management of Stationary Gas Engines Ore Dressing and Milling Theoretical Chemistry Practical Chemistry Elementary Inorganic Chemis- ' try Blowpiping Mineralogy Geology Prospecting Assaying Placer Mining Surface Arrangements at Ore Mines Preliminary Operations Ore Mining Supporting Excavations For those who do not wish to take up the complete Course, a shorter Course — the Metal Prospectors’ Course — may be obtained. Write for special circulars on either Course. International Correspondence Schools Drawer G, SCRANTON, PA. 3 Salary -Raising Training Mechanical Engineering Mechanical Drawing Stationary Engineering Those who are held back in their promotion by lack of a theoretical knowledge of the above subjects can find no means equal to I. C. S. Courses to overcome the obstacles to. their advancement. These Courses are thorough and concise in every respect and are remarkably easy to learn, remember, and * apply to the daily work of the ambitious mechanic.. They have been the means of advancing hundreds of ambitious workers and there is no reason why they should not be of the same benefit to you. Professor F. R. Hutton, Dean of the School of Engineering, Columbia University, and Secretary of the Ameri- can Society of Mechanical Engineers, recommends the I. C.. S. as follows. “I take pleasure in falling in with your suggestion which asks for a line of comment on the work of the Correspond- ence Schools, at Scranton, the result of a recent inspection. ... I regard therefore the I. C. S. as meeting a widespread need and as serving a very useful purpose. It seems to me.it opens a door of hope and of opportunity which would otherwise be almost of necessity closed to a large number of persons.” Our Complete Mechanical Engineering Course embodies two divisions, each of which treats of its own particular branches. The Mechanical Division contains 2,543 pages and 1,241 illus- trations. Starting with the simple subject of Arithmetic it includes Drawing, Electricity, Mechanics, Steam and Steam Engines, Applied Mechanics, etc. The Shop Practice Division contains 3,166 pages and 2,142 illustrations, and covers all those subjects that are ordinarily met with in connection with the work in machine shops, foundries, and allied industries. Write for special catalog on the Course that interests you. International Correspondence Schools Drawer G* SCRANTON* PA. 4 J c ' I , ►/ * •' ’ T ? V . - - • '7 V ’* 4 ;feT4 > ;VfiE ■