V^iifr:, v. ^^m- ^ ^v 5' \ CcvvVi ^y V J c. f^ !_X ^cTlS ^?^^1&^^^ PlATI I SUSl'KNl BETWFBX BROOKL" p !J BRIDGE. KD NEW YORK CITY. .See Suspennon Bridge p KNIGHT'S AMERICAN MECHANICAL DICTIONARY. A DESCRIPTION OF TOOLS, INSTRUMENTS. MACHINES, PROCESSES. AND ENGINEERING; HISTORY OF INVENTIONS; GENERAL TECHNOLOGICAL VOCABULARY; AND DIGEST OF MECHANICAL APPLIANCES IN SCIENCE AND THE ARTS. By EDWARD H. KNIGHT, CIVIL AND MECHANICAL EKGIKKER, ETC. Sinujsftrarcb WITH UPWARDS OF SEVEN THOUSAND ENGRAVINGS. VOLUME I. — A-GAS. "Thus Time brings all things, one by one, to sight, And Skill evolves them into perfect light." — Lucretius, Book V. First Steam Engine BOSTON: HOUGHTON, MIFFLIN AND COMPANY. SDlje KitjcrsiOf ^3rrs0, e. Scwing-Machines and Attialimeiits. Sheai'S. Sliipwrighting. Signals. Siieculunis. Springs. Steani-Engiiie (Parts and Appliances). Steam-Kngiiii's (Varieties). Stoves uiid Heating Appliances. Sugar-Machinery. Supporters. Surgical Instruments and Appliances. Syringes. Telegraphs. Telescopes. Tinman's Tools. Tobacco. Traps. Tubes. Turning-Tools. Type. Valves. Vehicles (Tools, Appliances and Parts of). Vehicles (Varieties). Ventilators. Vessels. Watches. Water- Elevators. Water-Wheels. Wea2)ons and Accouterments. Weaving. Wlieels. Wire-Working. Wood- Working Tools and Machines. Wrenches. LIST OF FULL-PAGE PLATES. Vol. I. Plate. Subject. Page. I. SUSPENSION BRIDGE. {East River, N.Y.) Frontispiece II. PIER AND CAISSON. {Illinois and St. Louis Bridge.) 49 III. ARCHED-BEAM ROOF. {Hudson River and Harlem R. R. Depot, N. Y.) . 139 IV. ARMOR-PLATED VESSELS. {English and American.) 152 V. ARTESIAN WELL. {Grenelk, Pans, France.) 163 VL BATTERY-GUN. {Gatling's, — Egyptian Service.) 249 VII. ATMOSPHERIC RAILWAY-BRAKE. {Westinghmise's) .... 356 VIIL KRUPP'S 1200-POUNDER BREECH-LOADING RIFLED GUN . . 448 IX. CHAIN-BRIDGE. {Over the River Dnieper, at Kieff, Russia.) .... 518 X. COMPRESSED-AIR ENGINE. {Bardonnkhe, Mont Cents Tunnel.) . . .602 XI. HOE'S TEN-CYLINDER TYPE-REVOLVING PRINTING-MACHINE . 670 XIL SINGLE LARGE-CYLINDER FOUR-ROLLER PRINTING-MACHINE . 671 XIII. FLOATING DERRICK. {Neiu York Department of Public IVorlcs.) . . .689 XIV. DIVING-BELL AND CORAL-DIVERS. {Gibraltar.) .... 714 XV. WORTHINGTON DUPLEX PUMPING-MACHINE. {Newark, N.J.) . . 763 XVL BREECH-LOADING FIRE-ARMS. {Ainerican and European.) . .851 XVH. BREECH-LOADING FIRE-ARMS. {Recommended by the United States Board, 1873.) 852 XVni. BREECH-LOADING FIRE-ARMS. {American and Stuiss.) ... 853 XIX. ENGLISH FLOATING DOCK. {The "-Bermuda.") 884 KNIGHT'S MECHAMCAL DICTM^ARY. A. Ab'a-cis'cus. A small sijuare stone or tessera fov a tesselati-il pavement. Ab'a-cus. An instrument used from time im- memnvial in performing the operations of addition and sulitractiou. A smooth board with a marginal ledge formed the WTiting and calculating table of the Greek school- boys and accountants. For wi'iting, it was strewn with sand, upon which marks were made with a stylus ; thus they learned to write, and on this they executed geometrical figures. The primary use of the hoard is indicated by its name, which is derived from the first three letters of the Greek alphabet, A B r. It was called an abax, and retains the name, but slightly modified. The abii.i- strewed with sand is ihe pulvis cruditus, or the Mensa Pi/tJmgorca of classic autliors. For aritlimetieal calculation, the same hoard was used without the sand, to contain the counters, which were arranged thereon in parallel rows, representing respectively units, tens, hundreds, thousands, etc. Solon (about 600 B. C.) refers to the arbitrary de- nominations of the several lines, in a metaphor which compares the different gi'ades of society to the differ- ent values of the counters in the several rows. The counters were pebbles, beans, or coins, espe- cially the former. The Greek word for the counters of the abacus was derived from a word signifying a pebble. Pythagoras, the great aritlnnetician, hated beans, — an antipathy he derived from the Egj'ptian priests, his instructors. About the same time Daniel was eating pulse in Babylon without gi'umbling, and Horatius Was hewing down the bridge of the Janiculuni. The Itoman word calculus, fi'om which we derive our woril cnlculale, was the diminutive of ccilx, a stone, and referred to the pebbles which formed the counters of the abacus. Sometimes the counters were shifted to the right in counting, sometimes totlieleft. Itis stated that the Greek and Roman practices differed in this re- spect. Several varieties of instruments are repre- sented on the ancient monuments. The step was easy from a fiat board with shifting counters arranged in rows, to a board with grooves in which the pebbles were rolled. Afterwards we find pellets Strang upon wires, and thus the Chinese have used it for ages. The illustration sliows the last-mentioned form of the device, an'anged for decimal counting. The number indicated by the beads on the right hand of the frame is 198,764, and it will be seen that by transposing the heads to one side or the other, as reijuired, either addition or subtraction may be read- 1 ily perfomied. A person accustomed to the instra- ment will perform theseoperationswith '^' " gi'cat rapidity and accuracy. The Chi- nese term the instru- ment a swan-pwan, and are very dexter- ous in its use. The original of the Chinese abacus has been supposed to be the "knotted cord," used in China for keeping accounts be- fore the invention of writing. The knots are made movable by substituting sliding beads, fleuce like Wise seems to have been derived the mode of keeping the Chinese Tung-tkn, or perforated coins, which are Strang upon a cord. One fonn of the Chinese abacus has two compart- ments, five beads in one and two in the other ; the fonner have tlie value of one each, the latter five each. Tlie wires are nine in number, and each runs through the two comiiartments. The Piomans, contrary to the customs of the Phce- nicians and Greeks, from whom they received their alphabet, expressed their numbers 1, 2, 3, not by the first letters of the aljihabet, but by strokes, I II 111; in this respect unconsciously copying the Chinese numerals of the same value. Tlie difference in the direction of the figures gives the numerals in each the same position ncross the column ; for the Roman writing is in horizontal colunm, the C'liinese vertical. The resemblance between the Chinese and Roman numerals extends much further than the above, and sliows a common origin. Perhaps it may be accounted for by the studies of Pythagoras in India, and the subsequent instruction ol Nunia in the school founded by the sage of Samos in Crotona, a city of Magna Grsecia. {Plutarch.) ABACUS. ABACUS. (commonly known us ' lU 11 12 13 Roman. X XI XII XIII Chinese + ± ± ± 20 XX 30 XXX The resemblance cannot be accidental. I'ytluigoras iinil K>iiis-fii-tzo (Confucius) were conteinporaues. Anotlii'V U)0(U! among the Chinese of e.xpiessing 2'K :iU, etc. wa.s by placing 2, 3, etc. before the si'rn of ten ; so tliat they in some degree anticipated the Hindoo, where a numeral before the zero expressed so many tens, e. g. Chinese. Arabic. = The great advance in the Hindoo over the other systi'ms of notation was in giving a place value to ligures. In Sanscrit, the initial rettere of the San- scrit munes of the Indian numerals are employed from 1 to 9. The original zero was a dot. The Greek letter omioron (o) was afterwards substituted, and forms our naught. It is amusing to see the com- bination of Hindoo and Roman figures during the fourteenth and lifteenth centuries, such as (Written.) (To be read.) x3 13 x4 14 40 1 41, etc. Showing that the force of the zero and the value froiu position were not understood at first, even when the new characters had become customary. The decimal and duodecimal systems of arithmetic wei-e in n.se in Egypt at the earliest period of its known history. For the respective systems the nuudjers of counters in the rows would vary, each line representing a multiple by 10 or 12 of the line below it. There is no representation of the abacus for count- ing on the Egyptian moTiuments. "The Assyrians counted by 60's as well as by lOO's." — Rnwlitisoti. The instrument was probably invented by the Chi- nese, and passiMl thence westwardly through India and Aiiiliia to Europe. The evidences of ancient trade o!i this line are found at both ends and at in- termediate points. The glass bottles with Chinese inscriptions, found with the Egyptian mummies, prove the existence of trade relations between those nations lii^l'ure the founding of Athens, and also dis- sijiate the myth of Pliny as to the discovery of gl:x,ss by certain mariners of Phoenicia, a few centuries previous to the time at which he made lus curious collection of vagabond information. Ov(U' this famous route travelled the mariner's compa.ss, gunpowder, the art of glazing pottery, of nn'dng papei' of pulp, and much else that we value. Kelting cif animal lilier was also ilerived from Asia, but proliaUly entered Europe by a more northern route. The Creek and Koman minieration was decimal, but their system of notation was very unfortunate, Hi any one may ascertain by trying a sum in multi- plication : CCXLVIII XLV ? The Oriental .system of notation was introduced by the Arabs, and was credited to them, but they more jiroperly term tli'in Imliini numerals, referring to their d(!rivation from the Hindoos. This system of notation pa.ssed with the Saracens along the north- ern coast of Africa, and was carried by them into Spain. The caliphate of Cordova was established by Abderahman, A. D. 755, and the university at that place was founded A. D. 968. At this dis- tinguished seat of learning was educated the famous Gerbei t of Auvergne. This enlightened eeclesiiLstic was successively a schoolmaster at Kheims (where he introduced the abacus, the Arabic numerals, the clock, the organ, and the globe), archbishcjp of Ra- venna, and, eventually. Pope Sylvester II., to which position he was elevated by the decree of the Em- peror Otho III. Patron and prelate died of poison shortly after, about A. D. 1002. Gerbert was probably the first to use in a Chris- tian school the nine digits and a cijiher, which proved, as William of Malmesbury said, "a great blessing to the sweating calculators." A translation of Ptolemy, published in Spain in 1136, used the Hindoo notation. Tlie Hindoo nu- merals were introduced into England about A. U. 1253. The accounts of the kings of England, previous to the Norman Conipiest — and the same is probably true of most contemporary European nations — were calculated by rows of coin disposed as in the abacus, that is, placed in parallel rows wdiieh represented gi-adually increasing denominations in the ascending series. At the Conijuest an amplification of the same idea was introduced, the calculations being performed by the teller, at a large table called a sac- carium. This had a ledge ai'ound it, and was cov- ered by a black cloth ruled with chequer lines. Hence the word Exchequer, as applied to English national finances. In the twelfth century, this table was five by ten feet, and its cloth cover was divided by vertical and horizontal lines. The horizontal bars represented pence, shillings, pounds, tens, hundreds, thousands of jiounds. Coins were used for counters ; the first and lowest bar advanced, by dozens, the number of pence in the shilling ; the second, by scores, the num- ber of shillings in the pound ; the higher denomina- tions by tens. This was a true abacus, and was used down to a comparatively recent period. The accounts of merchants were kept in Roman numerals till the close of the sixteenth century, and the use of the abacus was maintained to a much later date. Until 1600 its use was a branch of popular education. Offices for changing money came to be indicated by a checker-board, and the sign was afterwards appropi'iated by the keepers of inns and hostelries. This sliows that peopU' met at such jilaces to settle accounts, a friendly drink being a tribute to "ndne host." The Jerusalem and Lloyd's coH'ee-houses are noted in the history of trading companies ; the lat- ter especially. The checker-board on the doorpost of th(^ tavern is about the last phase of the abacus, in Eurojie at least. Tile checkers on the posts of an inn door are to be seen upon a house in disentombed Pompeii. The tiillii .system was also introduced into England at the Norman Conipu'st. This was not for calcu- lating, but for kee|iing accounts. The name of the device came with it across the Channel, being de- rived from the Ereneh hiillrr, to cut, the lalh/sticks being cut and notched with a knife. A scjuared stick of hazel or alder was prepared, and the money account was notched on the edge, small notches re])resenting pence ; largc^r, shillings ; still larger, pounds. The stick was then S]dit longitudinally, so as to leave notch-marks on eaeh ]iortion ; one part was laid away in the excheipu'r strong room, the ABAKA. ABRADANT. other was given to the creditor of tlie government. When the pereon came for payment, his portion of the stick was laid against that in possession of tlie exchequer, and if they tallud the claim was admit- ted, perhaps paid. This system survived the introduction of Arabic numerals into England about 670 years. In 1826 the time camj for the venerable system to abdicate in favor of the other Oriental method which had been asserting itself for so long. The pile of sticks, in companies, regiments, and brigades, that had liy this time accumulated was something terrific. The question was, How to get rid of them ? Prescriptive custom would prevent their being issued to the poor, or sold to bake the bread of the people, as the Alexandrian library heated the baths of that impe- rial city ; so one tine day in 183i tliey were to be privately burnt. A stove in the House of Lords was selected as a proper place for tlie incremation of anotlier relic of the past ; the wainscoting of the chamber protested by catching fire, the House of Lords set fire to the House of Commons, and both were burnt to the ground, — a gi'and funeral-pile. The bakers insisted for some years in keeping tally-stick record of loaves purchased by their cus- tomers ; some of us recoUect it. The oldest surviving treatises on matheraaties are by the famous Alexandrians, Eucl.,1, abo .t B. C. 300 ; Ptolemy, A. D. 130 ; and Uiopliantus, A. D. 156. Decimal fractions were invented 14S2. The first work on aritluu'tie ]iiil>lished in England was by Tonstall, Bishop of London, 1.522. Tlie Ital- ians had been in that field many years before. (Architecture.) The crown member of the capital of a column. Ab'a-ka. A fiber from which Manilla- rope is made. Ropes and caliles of this material Hoat in sea-water. Ab'a-mu'rus. .A. buttress or second wall, built to streii-_;tli(Mi another. Ab'ap-tis'ton. (Surgical. ) A trepan saw. Abat-jour'. (Building.) A skylight, or aperture for the admission of liglit. Ab'at-voix'. A sounding-board over a pulpit or rostrum. Ab'at-tis. (Fortification.) An obstacle employed in military operations for delaying the approach of an enemy and keeping him under fire as long as possible. It is formed of trees or large limbs bavin ^ the branches under two inches in diameter chopped off, the larger ones being sharpened and interlaced, and pointed toward the enemy. The butt cuds Fig. 2. /,l»n»VUimtfm;)lnnrllfc»t' u wall. A'brid. .\ brushing-plate around a hole in wliith a piiitli* wdvks. Ab-sorb'iug-^reU. A well or shaft, du^, borei., or drivi-ii tliiimjjh a retentive stratum to allow sur- faec or .sprin;; water to pass to a porous stratum be- low the t'onner, so as to foim an outlet for ilraina<.je. .Sueh wells aie maile at di.seretion in England, but in Krauee are regarded with jealousy, and their use is oidy pi-nnitted after an examination and report by ex|)i'rts as to their possible etl'ect npon watercourses, drainage or irrigation of other properties, etc. In the United States they are but little used, and pre not under public regulation. Absorbing-wells are known as dead wells in the South of England ; they are made in the gi-avel, the upper portion being elose-steened work and the lower open-steened work. The bottom is ,un- pavi'd. ti> allijw tlie water to infiltrate. A-but'ting-joint (Ctirijctdnj.) A joint in whieh thi- lllieis iif one piece are perpendicular to those of the other. (Mafhin ri/.) A joint in which the pieces meet at a right an^le. A-but'ment. A lixed iroint or surface, alford- iug a rchitivcly immovable obje<-t against which a biiily iiliKis or ]iresses while resisting or moving in the contrary direction. See I'lEU ; Skewback. 1. (Building.) Kg. *• A structure which receives the lateral thrust of an arch. The abutment may be a pier or wing ■walls foraiing ahor- izcntalarch ; orthe arch may be con- tinued to a pileil or liewn foundation, which is then the abutjneiU. 2. (MncJiincri/.) A solid or station- ary surtace against which a fluid re- acts. «. The wedge which lifts the ])is- ton of one form of ^ rotary steam - en - gine, and which forms a surface for the steam to react again.st as it presses the ])iston forward in its circular path. h. The wedge block in a rotary pump, where the piston traversi-s an annular chamber. ^,f<<\ c. One of the m- 5. ,^<\\V> cylinder heads of a steam-en- gine, receiving the back press- ure of the steam — which is made effective upon the piston. 3. {Cnrpni- tni.) The junc- tion of two Wg. 6. Movable Abutment. i. (Fire-nmi.i.) The block at the rear of the barrel of a fire-ann (es])ecially a breech-loader), which re- ceives the rcarwarii force of the charge in firing. It lia-s tlic function of the brccch-pluij or brccch-pin in the mu/zle-loading fire-arm. Pier Abutment. Piled Abutment. pieces of tini- bei, wliere the grain of one is Stationary Abutment. A similar term is applied to the corresponding por- tion in breech-loading cannon. In Fig. 6, the ahulmcnl D is movable upon an a.xis so as to expose the rear of the bore for the in- sertion of the cartridge. In Fig. 7, the iibiilinciit D is stationary, relatively to the stock, and the barrel slips away from the abut- ment to allow the insertion of the cartridge. The variations in the arrangement are very numerous, uu I the different devices form the subjects of numerous patents in the United States and foreign countries. See Fii!E-.\r..M ; BnEEin-L.i.XDiXG. 5. {Sit.tpemiini BritJiie.) The niasonrj' or natural rock in and to which the ends of a suspension cable are anchored. Fig 8. at a right angle to that of the other, or nearly so. Suspension Bridqe Abutment 6. (Hijdrnulic Enginccrinij.) A dam is in some sense an" abutment, as it sustains the lateral thrust of wati-r. Sec IXvM. A-but'ment Arch. .\n end arch of a bridge. A-can'tha-lus; Acan-tha'bo-lus. .\n instru- ment I'.ir cxtractiui; lhm)i> ass:iL'e to and from tlie boats along.-ide. Siile la Iders and stern ladders hang from tliese pirts of :i ship. Ac-cor'de-on. A/rcc-rrtvnnsfrunient introduced into England from Germany about 1S2S. The exte- rior fonn of this instrument is a parallelopiped. The action consists of a bank nf vibrating reeds or tongues wliieh are operated by the bellows. Keys open the air-ducts to the respective reeds as the bellows are e.x'pm.led and contracted. Dampers are attached to the end, which is grasped by the left hand, while the other end is furnished with keys by which the notes are somuled by the fingers of the other hand. The concertina is an improved form of the accor- deon. A common form of the accordeon is she 'm in' the engraring, which affords three riews : — A general exterior view ; A sectional view in the plane of the key -board, and exhibiting the separate wind-cells ; Fig. 9. A sectional view at right angles to the latter, and exhibiting the parts concerned in the course of the air, — damper, bellows, ducts, and cells. n iff, probably because belts were fonnerly made of that color. Until within a very few years a separate belt was used for suspending the bayonet-scabbard, passing over the left shoulder and crossing the cartridge-box licit diagonally on the breast, which was ornamented with a jilate at the crossing ; the intei-section of these two white lines, particularly when relieved against the dark-blue ground of the uniform, ren- dered the soldier as perfect a target as a marks- man need desire, the plate representing the "bull's eye." The cartridge-box belt has sometimes been dis- pensed with, particularly for riflemen, the whole weight of the accouterments, with, in this case, the addition of a heavy sword-bayonet and scabbard, being borne by the waist-belt, which of course had to be drawn veiy tight, forcibly compressing the abdomen, and causing gieat and unnecessary fatigue or even pennanent injury. Tliis arrangement was, we believe, generally con- demned by medical men, and in fact by every one who thought on the subject ; but as the weapon above mentioned was in very limited use, toward the close of the war esjiecially, the evil was not so gen- eral as it might have been. The cartridge-box for cavalry resembles in exter- nal appearance that for the infantry, but is smaller, and its two loops are arranged so as to pass the si>ber-belt through them. Those used by our troops ACCOUTERMENTS. ACCOUTERMENTS. during the late war were variously arranged in the interior to suit the sujiposed ne^'essities of the car- tridges of each particular kind of carbine, as Bum- side's, MeiTill's, etc., etc. That adapted for a paper cartridge, as Sliarjj's, of which a greater number was issued than of any other, ajipeared to answer reiy well for othei's, though, no doubt, for nietaUic cartridges a special bo.x is better. The cavalryman is also provided with a small box or pouch for revolver cartridges and a cap- pouch. The saber-belt, to which all the preceding are attached, consists of a waist-belt, with two brass rings for the shoulder-strap and saber-slings, and a bi-ass loop sewed at one end to receive the plate, which is rectangular and connects the two ends of the belt together. The shoulder-strap passes from a ring on the left side over the right shoulder, and returns, supporting the saber, which is suspended by two saber-slings passing from the brass ring at the waist-belt through two iron lings on the saber- scabbard, and buttoned. The accouterments for horse artillery merely con- sist' of a pistol cartridge-pouch and a cap-pouch, both similar to those above described, and a saber- belt which diB'ers from the cavalry-belt only in the omission of the shoulder-strap. A number of patents have been granted in the United States for improvements in the construction of, and in slinging accouterments. Since the com- mencement of the late war thirty-five patents have been gi'anted in this branch of inventions. Atten- tion has been directed to several points : — First. The ease of the soldier in carrying his knapsack, etc. has been attempted to be secured : 1. By making one portion of his accouterments balance another, as in Mann's, Mizner's, and Wood's ; 2. By a saddle-piece resting on the hips, as in Dick- ey's ; 3. By suspension-hooks on the shoulders, as in Sweeney's ; 4. By a frame reaching from the shoulders to the buttocks, as in Baxter's ; 5. By modes of shifting the weight occasionally to vary the point of pressure and relieve the otherwise con- stant strain, as in Short's and Siis's. SccuHiilij. In arrange- ments for making the knapsack do service as a shelter, couch, or mat- tress. Thirdly. In devices for the more compact arrange- ment of the compartments of the knapsack, haver- ; sack, or cartridge-box to increase their utility, read- iness for duty, and light- ness. The accompanying cuts will render it unnecessary to give a lengthened de- scription, and the exam- ples are placed in the or- der stated, founded on the similarities of purpose and means. Manx, December 8, 1863. The cartridge-box is worn in front of the person, and acts as a counterbalance to the oth- er accouterments, the weight of the whole be- Mann-! iMe ofsliv^nf " *".? thrown upon the AecoHterments. shoillders. Wood, May 15, 1866. The deWces refer to the means for slinging the gun, bayonet, cartridge- box, and canteen so as to countei-poise each other and the knapsack. The gun is hung to hooks ou the strap. A hook on the cartridge-box adajrts it to be attached to any part of the equipment. The bayo- net is also slung \>y a liook on its scabbard. When the accouter- ments are shifted to the I rear, the hind side of the/, lielt is connected to a ring beneath the knapsack, to help sustain the belt. MizXEK, January 16, 1866. The hai'ersack, which is earned on the shoulders, forms a coun- tei-poise for the cartridge- boxes, which are worn on the front of the belt ; the npjier portion of the divis- ional havei'sack is occupied by boxes, to contain three days' meat, cotfee, sugar, and salt, in separate ceases ; the lower or bag-like portion being adapted to con- tain an equivalent quantity of bread. A straj) pass- Fig. 13. Acfoitltrtneals. Mizn^fs Cavalry Accouterments- Fig. U. ing along the bottom and up one end of the cartridge-bo.x affords the means for elevating the packages of cartridges, wliich tit closely therein, and are diffi- cult of removal by the fin- gers. Dickey, March 21, 1865. To relieve the soldier of the backward pulling of the knajv sack it is partially supported , b}' adjustable standards lising*^/ from a saddle-piece, which j rests upon the hips. Sweeney, February 4, 1862. Tlie knapsack is so susi)ended that an air space may inter- vene between it and the back of the soldier. The cuned pads c rest upon the shoulder, Dichry^^ Knapsack Stipportfr- ACCOUTERMENTS. ACCOUTERMENTS. *'^^^--S|n Sweeney^s Knapsaci; Fig. 16. Fig- 16- and the bars £ descend there- from to the back j plate D. The I kiia[)sack is sc- IciUL-d by phites t'i tlicsc parts, ajid rigidly held at a distance I from the back. B A X T E 11 , March 17, 1863. This imjirove- ment is intend- ed to prevent the pressure of the knapsack upon the small of the back and the cramping of the movement of the arras, and it con- sists in supporting the Siick by strips of wood extending from the shoul- , der to the hips ; also in 1 securing the chest-straps as to leave the arms ' free. Short, January 28, 1862 ; December 14, 1862. The mode of slinging the knapsack permits it to be loosened so as to fall away from the shoulders and spine of the wearer, as a means of shifting the weight and pressure, and allowing circulation of air agaiust the back of the person. Tlie ari'iuigement also permits it to be raised Fig- li. Baxter^R Knerpsnck Sthig. 1864. This invention consists in the employment of a pair of suspending straps which pass over the Fig. 19. Fig. 20. Weber\f Knapsack, shoulder in connection with another shorter pair of straps attached to the top of the knapsack near its center, and also a pair of straps attached, one to each end of the knapsack, for the purpose of varying the position and shift- ing the weight of the same when desirable. Weber, January 31, 1865. The frame of the knajisack is capable of being changed into a couch, and the cover fonns a - shi'ltcr. The central section has jointed and folding si les. Krsii, March 2.o, S()2. The frame of the km.psu'k is made of two parts, hinged together. Sltort^s Kn(qi9aclc. or lowered in a vertical line according to the con- venience of the sol- Fig. 18. \- Knnpaacb. dier. Tlie neck and shoulder strap is con- uwted to the upper part of the knaji- 4ack by intermciliatc strajis, and the lower part of the same is designed to prevent lateral swaying dur- ing quick move- ments. Sus, May 17, Hush's Knapsack: At the thick end of one part are pivoted two aims, which, when tin own out, rest \ipon the edge of the knapsack, and serve to hold the canvas lor forming a bed. Fruusham and Levett, October 1, ISGl. This invention consists of an india-rubber casing made w;,tcr-tight and containing a bag of finely cut coik or other UUing, thus form- ing a life-prcseiver. A pocket is )iiade in the rubber casing to contain articles of cloth- ing, thus tbiming a knapsacl;, which wlien unrolled becomes a bed, the contained articles forming a pi low. MizNEU, Novendier 27, 1866. The knaji- sack is combini'd with a haversack. The straps that secure the parts of the sack together, when jiackcd and folded, are not sewed to the mati'iiul, but ai'c riveted to each olhi'r, and also to the sling-straps. The latter pass froiu the knapsack over the slunilclers, be- neath the aimiiits, and unite liehind the back. MoEvoY, Jainiary 7, 1862. The body is Fig. idl. Frotlsliam anrt LeietCs Kitapsaek> ACCUMULATOR. ACHROMATIC LENS. Fig. 22. Fig. 23. AlizjtfT^s Knapsack. McEvoy's Knapsack. made of wicker-work, ami lias partitions ami doors ; it is covered with watcrjiroof material, and con- tains medicines, lint, banda.i,'es, splints, and surgical instruments. It is designed to Le carried by the surgeon's orderly in an engagement or during field duty. Ac-cu'mu-lator. .\n iiulia-rubber spring which accuiualates lifting force, and is applied to many z Fig. SI. "^^ "EHT r^'^.^ r».JSA, ^^ specific pui'})Oses on board ship, in machine- shops, etc. An apparatus used in working hydraulic cranes and other machines where a steady and powerful pressure of water is rojuired. The accumulator is intended as a substitute for a natural head, as being more compact. Sir William Araistrong, in the fii-st applications he made of this principle to hydraulic cranes, employed a natural head of water as the mo- tive agent, obtaining the same by pumping water into tanks at an elevation of about 200 feet ; but subsei[uently he has always employed thcaccumulut- or, as oftering the advantages of greatly increased capacity for pressure, and a less prime cost of erec- tion. The acciunulator is shown iu Fig. 24 ; it con- sists of the large cast-iron cylinder n, fitted with the plunger b, which works water-tight by means of the gland c, and packing. To this plunger is attacheil, by means of the bolts /, and strong cast-iron ci oss- head e, the loaded weight-case d. Thus a pressure is obtained upon the water in the cylinder, cipial to a column of water 1500 feet high, or tiOO lbs. upon the square inch. As the water is jumiped into the cylinder by the pumping engines through the pipe h, the piston, with the weighted case, rises, being guided by the strong wooden framework j/, and is made to regulate the amount of water pumped in, by actuating a throttle-valve in the steam-pipe of the pumping engine, which it closes after baring reached a certain height. When the cranes, etc. are in operation, the water passes from this cylinder through the pipe )', to those actuating the motion of the cranes, and the weighted plunger naturally de- scends, always keeping up a constant pressure upon the water ; in descending, the same causes the throt- tle-valve to open again, and the water is again pumped in. Aces, iyauiical.) Hooks for the chains. A-cet'i-fi-er. An apparatus for exposing cider, wort, or other wash to the air to hasten the acetiti- cation of the fermented liquor. See Guabvator. Ace-tim'e-ter. See Acidimeteu. Ac'e-tom'e-ter. A hydrometer suitably gradu- ated lor ascertaining the strength of acetic acid and vinegar. Ach ro-mat'ic Con-dens'er. An achromatic lens or comliination used to concentrate rays upon an object in a ndcroseope. See Carpeakr on the Micro- scvjir. ].p. 117 -int. ed. ISo". Ach 'ro-mat'ic Lens. Achromatic, literally col- orless, lenses were first introduced by John Dollond, of London, about the year 1758. Ever since the in- vention of the telescope it had been a desideratum with astronomers and ojiticians to obtain a lens which would give a perfect image free from color with a moderate focal length, it having been found by experience that it was necessary to increase the length of focus of the object-glasses of tclesco]ie3 in the proportion of the square of the magnifj-ing )wwer desired, to obtain distinct vision. This was owing in part to the distortion or spheiical aberration, caused by the rays striking the lens at gieater or less distances from its center, being refracted at dif- ferent angles in proportion to the gieater or less con- vexity of the lens, and converging to difi'erent foci more or less distant from the latter ; but principally to the dispersion or decomposition of the light, as in prisms, to two of which, joined at their bases, the lens is in fact equivalent. See PniSM. This fringed or colored appearance may be obsei-ved about the margin of almost any object viewed through a lens of short focal length, such as an or- dinary microscope. The excessive length which had to be given to re- ACHROMATIC LENS. 10 ACOUSTIC INSTRUMENTS. fcu-tiiig telpst'opos in order to obtain wliat i.s now consiilereil a vury moderate niagnil'ying jiower, 100 feet tor a i)o\ver of 200, led Gregory and Newton to the construction of reHeeting telescopes (see Tele- .-scopk), and these for many years were almost the only kind in use. The dispersion of light, or the length of the spectrum formed by prisms having the same refracting angle, varies greatly in ditt'erent sub- stances though their refracting powers may be ecjual or nearly so. Newton had supposed that the dispersion was al- ways proportional to the refraction, and it was in the course of a seiies of experiments undertaken in order to verify this theory of Newton, which had been controverted, that Dollond was led to his dis- covery. He found that a prism of white flint glass whose refracting angle was about 25 degi-ees refracted the light in a nearly equal degree with one of crown glass whose refracting angle was 29 degrees, but that the dispersive power of the former was much greater ; so that, when thej' were applied together to refract contrary ways, a beam of light passed through them was separated into its component colors, although the incident and emergent parts of the beam contin- ued parallel. From this he inferred that if two lenses, one con- vex and the other concave, — which are in effect equivalent to two prisms refracting in different ways, — were so arranged as that the dispersive power of the flint glass would be corrected by the crown glass, that the image produced by the excess of refraction of the latter would be sufliciently colorless and dis- tinct to bear an eye-glass of much shorter focal length and consequent magnifying power than could be applied to a non-achromatic, double-convex lens, formed of a single piece of glass ; and by further experiment he ascertained the most advantageous focal lengths to be given to each glass in order to produce clearness and distinctness. He adopted a combination of three lenses, the middle one being of flint glass and double concave, and the two e-xterior ones of crown glass, double convex, believing that Fig. 25. it produced better re- sults and more ettcctu- ally corrected the spher- I ical aberration ; the I ombination of two ;;Iasses is now, however, , universally adopted. It has been proposed ' to use metallic solutions and other li(iuids which have a higher dispersive powjr than flint glass, enclosed in glass disks of the proper curvature her- metically sealed at their edges, in place of that article for the concave lens, but though several of these substances ajipear to have given excel- lent results experimentally, they have never been brought into general use. On account of the difliculty of obtaining a good article of flint glass, more particularly, and the trouble and skill required in grinding and polishing the faces of each piece so that they may have the proper curvature and fit accurately together, achro- matic lenses have always been and will probably continue to be very expensive, especially the larger sizes. Dr. Dick mentions one of 5i inches aperture and 5i feet focal length, which cost 200 guineas. Plopl, an optician of Vienna, has recently invented an improvement on the achromatic, which he calls the dialytic telescope, in which the several ditt'erent kinds of glass composing the compound object-glass are not placed close together, but at regulated dis- tances apart. This arrangement allows a shorten- ing of the tube. Chester More Hall, of Essex, England, invented the achronuitic telescope in 1729, but did not make it public. Uollund had to invent it over again. Ac'id-im'e-ter. An instrument for determining the jiurity or strength of acids, founded on the pnnciple that the strength of any sample of acid is proportionate to the quantity of alkali which it will neutralize, or the quantity of carbonic acid gas which it disengages from a carbonate of soda or jiotash. An accurate and economical apparatus for this purpose is proposed by Dr. Ure, as follows : a graduated glass cj'linder, having a discharge tube and capable of containing 10,000 grains of distilled water, is attached by a flexible tube to a Florence flask containing a supersaturated solution of car- bonate of soda or potash, in which is a test-tube containing a .sufficient proportion of acid by weight to evolve carbonic acid gas equal in volume to the contents of the cylinder. Bicarlionate of soda is prefeiTed, as one equivalent of any acid disengages from it two equivalents of carbonic acid gas, and the quantities of various acids required to evolve a vol- ume of gas equal to 10,000 grains of distilled water are as follows : — Anhydrous sulphuric acid, 16.80 grains. Oil of Wtriol, 20.58 Anhydrous nitric acid, 22.67 " " hydrochloric acid, 15.33 " " acetic acid, 21.42 " Crystallized citric acid, 80.64 " ' ' tartaric acid, 63.00 " By tilting the flask the test-tube is upset and the acid brought in contact witli the alkaline solution, liberating the carbonic acid gas, which passes over into the cylinder, displacing a bulk of water equal to that of the gas evolved, the amount of which is shown Ijy the graduations on the side of the cylin- der. This indicates the strength of the acid. For example, if the water should be depressed to the mark 50 on the cylinder, it shows that the sample contains but fifty per cent of pure acid. This appa- ratus is the converse of tlie alkalimctcr, wliicli see. A-cis'cu-Us. A small mason's pick, with a flat face and jiointed peen. A-cock'bill. 1. The situation of the yards when they are topped up, at an angle with the deck. 2. The situation of an anchor when it hangs from the cat-head by the ring only. A-cou'me-ter. An instrument invented by Itard for measuring tlie degree or extent of hearing. A-cous'tic In'stru-ments. Instruments or ap- paratus pertaining to the ears, the perception, measurement, or projection of sound. I. Those appertaining to the ear are, — 1. Pro- sthetic. 2. For e.rploratio'i} . 3. For o})cration. 1. Of the prost/ictic are the Auricle. Cane Trumjiet. Cornet. Conversation Tube. Ear ; Artificial. . Ear of Dionysius. Ear Trumpet. Sonifer. Tympanum ; Artificial. 2. Ex-plorritmn. Acoumetcr. Ear Speculum. Oto.scopc. ACOUSTIC TELEGKAPH. 11 ACTION. 3. Operation. Ear Spoon. Ear Syringe. Eustachian Tube Instrument. Meatus Knife. Organic Vibrator. II. Instruments for making or conveying audi- ble sounds. (Not including those of a prosthetic nature cited in Class I.) Acoustic Telegraph. Air pipe. Alarms. ( Varieties ; see Alarms. ) Musical Instruments. (Varieties, see Musical Ix.STKU-MENTS.) Speaking Trumpet. Speaking Tube. Steam Whistle. • III. Instruments for measuring the quality of sound, the extent of hearing, the number of vibra- tions in a given time, etc. Acoumeter. Kalcidophone. Metronome. Sirene. Sonometer. Tonometer. lY. Auscultation Instruments. Percussor. Pleximeter. Stetliometer. Stethoscope. (See the above in their alphabetical order.) A-cous'tio Tel'e-graph. A telegraph making audible instead of visual signals. In this sense — the most general — every sounder may be included in the class, for it is capable of being, and is, used to convey information by an arrangement of repetitive blows and intervals. The present common use of the Jloi-se instrument brings it within this category, the signals being read by ear rather than by consulting the paper ribbon. The speaking-tube maj' be considered another firm, conducting a puff of air to the other end, where it operates a whistle, or the sound is recog- ni2ahle as an audible expression. Bright's (English Patent) is adapted to communi- cate phonetic signals. It consists of an axle having a magnet aud double arm ; the magnet, when acted upon by electro-magneric coils, causes the a.xle to vi- brate or deflect in one direction, thus sounding a beU by means of a hammer-head on one arm ; the subse- quent reversal of the electric current causes a muf- fler on the other arm to stop the sound. In a more perfef t form, Bright's Acoustic Telegraph con.sists of a hammer in connection with a lever, which is acted upon by every polarization of a set of electro-magnets by the local current, and there- upon strikes a small bell. A pair of these bells are connected to each wire ; one bell is struck by the passage of the positive, and the other of the negative current, the alphabet being readily formed by the difference in their tones and the number of beats. Another form of audible telegraph consists of a wire which is tapped and conducts the sound to a resonant diaphragm. Wilson's Patents, 1866, refer to the production of a musical note by the action of a valve governed by the electro-magnetic current. The sound is continuous or intennittent, and variable in tone or pitch, as may be required. Ac'ro-ter. A small pedestal placed on a pedi- ment and serving to support a statue Ac-tin 'o-graph. An instrument for registering the variation of tile chemical intensity of the sun's rays. As contrived by Mr. Hunt, it consists c f a K.xed cylinder on wliich is placed a prepared photo- gi-aphic paper covered by a revolving cylinder hav- ing a triangular ojiening divided by bars through which the direct rays of the sun pass ; their effect upon the paper indicates their chemical intensity at difl'erent times. Ac'ti-nom'e-ter. An instniment for measuring the I'owei of the sun's rays, invented by Sir .1. F. "W. Hersehel about 1825. A hollow cylinder of glass filled with a colored liquid is soldered to a theniiometer-tube blown into a baU at the upper end ; being exposed alternately to the sun's rays and removed to the shade, a comparison of the differ- ences of expansion of the liquid indicates the rela- tive intensity of the solar radiation. The discovery of the presence of another principle, associated with the light and heat derived from the sun, seems to have been made some years ago by Mr. E. Hunt in England. Sir J. Hersehel proposed to establish, as a unit for the intensity of solar heat, that value which would, in a minute of time, dissolve a thickness equal to one-millionth part of a meter of a horizontal sheet of ice, when the sun's light falls vertically upon it. This he calls an adine, and from experiments made by him at the Cape of Good Hope he detei mined the value of a degree on the scale of one of his acfinmneters to be equivalent to 6.093 actiiies. The actinometer is useful in detennining the quantity of solar heat which is absorbed in passing through the different strata of the atmosphere, for which purpose the observations must be made at stations differently elevated above the level of the earth or sea. It may also be employed to deter- mine the diminution of heat which takes place during eclipses of the sun. See Manual of Scientific Inquiry, published bj' the English Board of Admiralty. One form of actinmncter is sometimes called a photometer. The former name indicates that* its purpose is to deteraiiiie the actinic power of the solar rays, while the latter name indicates a meas- urer of the intensitii of the light. One use of the actinometer is to ascertain the proper time for exposing a plate in the camera, or a sensitized paper in the printing-frame. The box has a spring bottom and a glass and wooden cover. On the under side of the glass are secured a series of thin strips of paper ananged in layers so that each layer projects over the edge of the strip above it, thus producing a graduated semi-transparent me- dium. The number of laj'ers of any particular point is indicated by black figures on the lowest strips of paper. Upon this false bottom is spread a series of strips of paper rendered sensitive by saturating with alkaline chromate. The apparatus is then exposed to the light, and the strips of sensi- tive paper will be successively darkened according to the depth of over-lying paper. See Photometer. Ac'tion. An exertion, applied in machinery to an effective motion ; &.% — A single action ; illustrated in the ordinary Uft- pump, the atmospheric engine, etc. A double action, in which the go and return mo- tions are each made effective or are positively effected by the motor :, as the double-acting pump, throwing a stream at each course of the piston ; the ordinary high-pressure steam-engine, in which the piston is driven each way by the force of stream. (Music.) The movements or working parts of a stiinged or wind instrument, which is operated by ACUPUNCTURATOR. 12 ADDRESSING MACHINE. a key-board ; such as an organ, inano-foite, nielo- deon, etc. It includes the portion between the keys and the strings, — the portion engaged in slrikinrj and damping. Tlie axlions are known, by a peculiarity in tlui in.strunient, as (jraiul, square, piccolo, sinijle, dnuble, tiprii/h/ actions ; or IVom the inventors, as Broad- \\ood's, Col'iird's, Fravd's, Steinway's, etc. See PlANO-FnUTK. Fk'. 26. Piano-Fortf Action A is the key ; B, the hammer whicli falls back upvin the cluck, and a bar mid length of the stock, c. died the Immmer-niil. C is an adju.stable bar on wiiicb. is mounted the jock, whereby the hammer is actuated. E is the rail to which the hammer is hinge J. Ac'u-puuct'u-ra'tor. Periveil homacus (Lat. ), a needle. An acieulai- instrument for treating certain complaints, such as headaches, lethargies, etc. It is of gi'eat antiipiity in the East, and of late years it has been introduced somewhat extensively into Europe and the United States. The essential apparatus employed is simply a set of needles set in a handle, or detai'lied needles, which by a slight rotary move- ment aie passed to the reipiired depth beneath the tissues and allowed to lemain for a length of time varying from a few minuios to an hour. In the si.xteenth century, according to Jerome Car- dan, the jtraetitioners of this art travelled from place to place, and rubbed their needles with a magnet or substance which they pretended renderi-d their insertion ]iai]de.ss. Without any such application, however, the punctures are so minute that pain is not felt after the lirst insertion of the needle. The needles are sometimes used for conducting the galvanic current to parts at some distance be- neatii the surfa,-e of the skin, and are sometimes made hollow foi' the injection of a sedative into the tissues, for the re'ief of neuralgic alfections. This latter mode of application was suggested by Dr. Alexander Wood of Edinburgh, Scotland. See AN^ESTUi'.Tia Arl'AR.VTUS. It is sometimes called a Dermopaihic or IrrUation Inslrimienl, and is used to intidiluce a vesicatory liquid beneath the epiilermis. Flu.MKXicii's in.strunient, March 18, 2, may be considered a type of its fflBS" /J class. The piston containing the needles " Blliii.-!!' is adju.stable in its cylinder, which holds the medicinal jtreparation. The neeilles ^ project tlirough the diaphragm to the required extent, and the episi)astiG liquid insinuates itself along with the needles into the punctures;. Klee's acupuncturator, June 19, 1866, has a regulating nut ;;, to adjust the depth of penetration of the needles which |irojei-t through the diaphragm to con- duet tlie liquid from the cylinder A and introduce it through tlie skin. The needles 6 are stocked in the ]iiston B, whose .stem d is sleeved in the stem-screw cf. In Oriental eountiies the needles are made of gold or silver. In China their manufacture is regu- lated by hiw. They are of ditl'i'rent sizes, some about four inidies in length and having spiral han- dles to facilitate tlieir lotation after insertion. They are driven in by a small, lead-loaded hanuner with a leathern face. Their use is very common in China and Japan, and was communicated to Europe by the ])hysician to the Dutch Em- bassy in tlie seventeenth century. It was revived in France in 1810. The English needles are long, made of steel, and liave knobbed heads to facilitate turning after introduction. The tendency here, judging by the jiatent.s, is to have the needles in clusters. The 0]Jeration is well performed by a tubu- lar needle connected with a syringe, by which ^H-^JJl^i wuak solution of morphia is iiijecti'd into a ' { tliseased tissue, producing local aiuesthesia. See ANiESTllETIC 1.NSTRUMENT.S ; llvi'ODEU- liic SvKiNGE. For the reverse use of hol- low needles, see TuocAR. A'cus. A needle. As, — Acus Cannulata ; a trocar, or tubular needle for discharging liquids. Acus Iiitcrpumluria ; a couching-needle used in operations for cataract. Acus (Ip)ithalmica ; one used in operations for oplithulmia or cataract. Acus Triquctrii : a trocar, or three-sided needle. Ac'u-ten-ac'u-lum. A needle-holder or for- ceps ; a nei'dle-handle ; a purtc-aiguillc. A-dapt'er. 1. A glass-tube open at botli ends, and used to connect a retort with its receiver. 2. A receiver with two opposite necks, one of which admits the neck of the retort while the other is joined to another receiver. It is used in distilla- tions to give more space to elastic vapors or to increase the length of the neck of a retort. See Aludel. 3. A tube to adapt or tit an accessory ajijiaratus to the body of the microscope, as the adapter which canli's till- analyzer of the polarizing apparatu.s, etc. Ad'a-tis. A species of fine cotton cloth made in India. Ad-den'dum. {Oearin;/.) The difference between the real and the geometrical radius of a circular cog-wheel ; that is, between the radius of the ^^//c/i. circle and the outer circle which touches the crests of the teeth. Ad'dice. The obsolete name of an adze ; which see. Add'ing Ma-chine'. An instrument or machine by wliieli adding of numbers is efl'ected. See Abacus ; .ViiriiLMiiMETEi!. Ad-dress'iiig Ma-chine'. A machine for ad- dressing newspapers and magazines in which the same serii's of names is repeated from time to time as the day of issue recurs. There are two n.odes. One is to )uint the addresses consecutively . upon sli]is wlii(h are gummed on the back and fed intennittingly to the cutter which cuts olf each adilress. This is then jnessed upon the folded liaper or pamphlet, which is placed in jiosition to receive its direction. The other mode is to set up the type of each address in a form, and so arrange the Ibrms that they are successively presented at a spot to which tlu; enveloped papers are consecu- tively fed. Over twenty piatents have been granted in the United States on machines for this jmrjiose. One of the earlier forms of this device is that de- ADDRESSING ilACHINE. 13 ADDRESSING MACHINE. scribed in Moesek's patent, June 24, 1S51. The different addresses are set up in columns in a galley, and are brought under the action of a stamp, being moved intermittingly by means of a slide ; the addresses are exposed seriatim at a slit in a plate, allowing the paper or object to be printed to be pressed down upon the address beneath the slit of the plate, and shielding the paper from the ad- joining lines. This series of addresses forms a me- chanical record on which changes may be made as they become necessary. This patent was reis.sued January 30, 1S66, audwas extended' to the year 1872. Campbell, Januari,- 20, 1S63. The addresses are set xip in parallel columns, and are secured in a common chase. The machine is supported over the chase by end-pieces, and is automatically advanced after each depression of the platen. Resting upon ways which span the chase is a traversing bed-piece with an upright, afforxliiig a pivotal attachment for a lever which alternately elevates and depresses a platen on the guide-rod. The elevation of the lever, by means of the toggle, actuates the wheel, which, mashing into a rack, ad- vances the jilaten to deliver another impression on an advanced point. Alter exhausting all the addresses in a given column, the bed-piece is moved later- ally to bring the platen into correspond- ence with the next column. A paper is fed beneath the platen just previous to the down stroke of the lever. The foi-m is previously inked so that each address is ready to deliver its impres- sion when called on. Tiffany and Soule, March £0, 1860. The t^Tie addresses are contained in a partitional galley or chase, which is moved by a pawl dependent from the platen lever, as the latter is raised. A pinion on the shaft, whose ratchet is thus actuated by the lever-pawl, is the means of forwaniing the galley, a cog at a time, and each line of tj'pe as it comes to the wide pinion is separated from the rest by elevation so as to ex- pose it at the slit in the plate above, in contact with the paper which is placed upon it below the de- Kg. 2B. Fig. 29. Soide's Addressing Machine. ScHi'H, April 26, 1S59. The hopper C contains the documents, which are discharged consecutivelv Kg. 30. ^ ^fl||ip nmrmTrrfHrf[ TJ 3 Tiffany and Souie's Addressing Mac/itne, scending platen. A sheet metal plate depresses the type after the impression is delivered. " SoiLE, October 2, 1860. The forms of the ad- di^esscs ai-e arranged in columns in the chase F, and the plate moves intermittingly above it. The oscillating platen C is pivoted to bearings D, on the jilate ^, which has a slit brought into correspond- ence with each address in turn. The plate is advanced intermittingly, after each impression, by the contact of the descending lever with an oblique end to one arm of the bell-crank which is pivoted to the plate, the other end of the lever engaging a rack on the bed-plate. Schuh's Addressing Machiru. by the movements of a sliding gate which is pro- vided with a heel or step w Inch drives the document before it from beneath the pile. The t}-pe ad- dresses are fed down an inclined board H, and thence are forwarded along a level channel E, to the rig. 31. point beneath the platen P. On aniving at this point they are successivelyrf raised by the action of a piston L, which is raised bv a cam on a hoiizontal shaft beneath. The ad- dress is elevated to meet the descending platen P, and the paper introduced between them receives the pressure from one and the impression from the other. The type is then forwarded by the type-shifter G, along the elevated channel g, from whence the addresses are removed in gangs. The notice-bell R is actuated by the type at inten-als to an- nounce that a certain gal- ley is exhausted. Dnvis'a A Unvins .Vackinr. ADDRESSING MACHINE. 14 ADDRESSING MACHINE. Davis, September 6, 1859. The blocks r on whicli tlie addresses are cut or placed are attaclied in compact coluiim, but indepimdently, to a Hexible baml wliicli nins over two rollers p t, tlie lower one, t, being of small diameter so as to cause the o\iter edges of the blocks to separate at the lowest point of their revolution, as seen in the figure. \iy this separation the lowest block for the time being is distinctly presented to the paper or envelope which is placed beneath it, and raised to the type by ilie treadle which raises the table a. i'ig. 32. Boiclus^s Addressing Mac/tine. BoWLUS, May 1, 1860. The endless chain has type-bo.xes c, wliich have spring sides for clasping the forms, each of which constitutes an address. The forms are placed in a column in the feed-bo.x ^4, are taken one at a time by the pockets in the feed-wheel B, and are trans- Fig. 33. ferrcd to the type-boxes in the endless chain. They are carried by the latter beneath the inking-roUers 7, which are presented con- secutively to the forms, hav- ing previously received ink from the ink-supply rollers O H. The paiier-feediiig and iirinting-roUer M lias a travelling apron whicli feeds the strip of paper to the fomis, and the latter are cleansed, as they return in the re- versed position, by the rotary brush A", whicli rotates in the wash-tub 0, and in contact witli tlic type. Dory, January 26, 1864. Tliis machine is for cut- ting oH' addresses I'rom a strip of paper previously printed and gummed on the respective sides. Tlie strip is fed from a spool 0, and is drawn over the concave bed A' by the oscillating arm F, whose finger i engages the paper. The gummed side of tlie paper being underneath is moistened by the wet sponge a, and pa.sses between the stationary cutter E and the descending cutter D, whicli is depressed by the spring plunger b, and so actuated by the spring d as to make a shear-cut upon the strip of paper as it removes the address. The feed levers F are ]iivoted to the frame, and actuated by projections fiom the descending plunger. In Dick's machine, October 4, 1859, the ad- dresses are set up in columns in a form, and the printed sheet is cut into sti'ips, each of which has a column of addresses. The reverse side is pasted, and tlie sli[) is fed forw-ard one address at a time ; the descending stamp-shear removes the address and presses it upon the wrapper or the paper, as the case may be. The pressure of the machine on the jiile of wrappers operates the cutter and removes the label. In Peck and Wright's machine, January 12, 1864, the wooden blocks upon whicli the addresses are cut are bevelled upon one side, so that a series of them, wlicn placed in a column galley, forms a continuous ratchet, of which each block is a separate tooth liy wliicli they are fed forward, preserving the requisite intervals. in some cases the i|uads of the forms afford teeth by whicli the column is advanced. B.iiiuiNGTux, June 14, 1S59. The cylinder has Fig. 34. JJ Dott/^s Addressing Machine, Dirk's Addressing Machine. grooved ribs for holding forms of tj-pe and present- ing them consecutively at the proper point for delivering an impression. M.\RSHALL, No%'ember 1, 1859. The "forms" constitute links of an endless chain, which unwimls from one drum and winds on to another, being inked on their passage by one set of devices, and the con- secutive links depressed by a stamp on reaching a certain point of their progress at which is presented the pajier or envelope to be superscribed. NoRDYKE, March 1, 1859. The envelopes on an endless conveyer are fed beneath the forms wliicli are fed upon one track and discharged u]ion another, being subjected at a given point to the action of a pressure-roller. Carpenter, May 5, 1857. The forms are placed in pockets in the periphery of a wheel. Tlie news- ADHESION CAK. 15 ADOBES. paper being held above the form, the platen is de- pressed by a treadle and the impression obtained. On releasing the treadle the spring raises the platen, and the pawl turns the cylinder one tooth, bringing the next name in series beneath the platen. Campbell, January 17, 1860, patented a machine for printing addresses on the margins of news- papers, simultaneously with the piinting of the newspapers, by means of cells or bo.xes, containing the addresses set up in tj"]ie and conveyed to the form by means of an endless apron having an auto- matic, intermittent movement. B.\TLEY, January 17, 18(50. The type are ar- ranged on slats, so connected together as to be moved successively through the machine. The pa- pers are fed into the machine by finger bars and spurs, and the addresses elevated in succession to make the impression. Lord, September 7, 1858. The t>'pe forming the addresses are inserted in boxes secured spirally on the periphery of a revolving cylinder. The newspajiers or envelopes are successively pressed against the type in the boxes by a horizontally reciprocating platen whose action is in concert with the cylinder. The inking apparatus is caused to follow the spiral arrangement of the form, being gradually moved by a screw similar to a lathe-feed screw. H.\ERiLi)'s machine (English) consists of a slid- ing groove of some length, in which is placed a galley containing as many of the required directions as it will hold set up in type and locked up. A treadle moves it along, one notch at a time, under a parch- ment friskct, till a direction arrives just under the aperture cut in the frisket, the newspaper envelope is laid over it, and the treadle brings a platen down upon the newspaper. The galley then passes along, notch by notch, till its directions are exhausted, when it is superseded by another. Ad-be 'sion Car. A car whose wheels are adapted to grasp a rail or to bear upon it in such a way as to have an adhesive or tractive power gi'eater than that due merely to the weight of imposition. Among the foi-ms may be mentioned : — The cofigcd rati. See E.\ilro.\d. The center mil, with a horizontal pair of gripping- wheels. See R.\iLRO.A.D ; Centek R.\il. Another foiin is a wheel with an angiilarly grooved periphery, which bites the flanges of a doulde-headed rail. In the early history of railroad engineering many devices, especially the cogged rail, were em- ployed to give adhesion, or tractive giip upon the rail. These were eventually laid aside as more cor- rect views were attained. In climbing inclined planes, however, devices of this kind are j'et found useful, and are noticed under the appropriate heads, cited above. Coefficients of Adhesion of Locomotives per Ton upon the Driving- Wheels. Lbs. When the rails are very dry, . . 670 When the rails are very wet, . 600 In misty weather, .... 350 In frost or snow, .... 200 In coupled engines the adhesion is due to the load upon all the wheels coupled to the drivers. The adhesion must exceed the traction of an engine upon the rails, othei-wise the wheels will slip. Ad'it. A drift, or nearly horizontal tunnel form- ing a road or drain in a mine, by which the ore is extracted or water earned otf. Its discharging end is at the natural surface. A day-hvcl, or sough. The great adit in Cornwall drains the waters from the Gwennap and Redruth mines, and is near- ly thirty miles long. It discharges its waters into the sea, forty feet above high-water mark. Adits may be driven either along the course of a vein or bed or through an unproductive stratum of rock, and are frequently run in a direction trans- verse to the general bearings of the veins or lodes, with a view to exploration ; such an adit is termed a cross cut. In the early working of a mine, the adit, from mo- tives of economy, is made as short as practicable ; but as the operations progress it is often advisable to drive another at a lower level and of greater length, to avoid the difficulty of pumping or lifting the wa- ter from a considerable depth. Ad-just'ing Screw. A set-screw of an instru- ment by which one part is moved upon another, either for focus, level, tension, or otherwise. Ad-just'ing Tool. (Horo!ogy.) A tool by which the snail of the fusee is regulated so that its increase of diameter may exactly countervail the decreased strength of the spring as it unwinds in the barrel. The object is to obtain an exactly equal power at all times upon the train. Ad'mi-ral. A leading ship of a squadron. (From Sar. Emir, the Sea. ) " To be tbe mast Of some great ammiral." — Paradise Lost, B. L A-dolje. Adobes, or unburnt bricks, are prin- cipally in vogue in the plains of Shinar and Egypt, and in China and certain portions of North America inhabited by the Puebla Indians. If well burned, he clay forever loses its plasticity, and cannot again ' reduced to a mortar. If it be merely dried, it will assume its original condition, as it came from the pug-mill. Such has lately (1871) been the experience of the Chinese in the vicinity of the Hoang-ho, whose houses of adobes are reduced to mud-heaps by the overflow of the river. Jlr. Tondinson, C. E., of London, has treated this matter more fully than any other author writing in our language, and he says : "The first action of heat is to drive off hygrometric water ; the clay then becomes dry, but is not chemically changed, it does not cease to be plastic. On continuing to raise the- heat, the chemically combined water is separated, and the cla\' undergoes a molecular change which prevents it from taking up water again except mechanically. With the loss of this chemically combined water clay ceases to be pla.stic." In the directions which have been published for building with adobes, it is recommended that they should be guarded, by some material imjierrious to water, from absorbing moisture from the ground, and also that the roof should be made to project not less than two feet in order to shed the water and prevent its running down the walls. These direc- tions seem to indicate the weak point, and the ex- periences derived from the dry plains of Asia and Africa, and the elevated arid regions of Northern Mexico and Lower California, do not apply so well to our more humid climate. The mold for making adobes resembles the ordi- nary brick-mold in basing four sides and having handles at the ends, but no top or bottom. It is much larger, however, and sometimes a pair are placed in a single frame. It is placed in position on the drnng-gi-ound, filled with clay, and when the top is smoothed by a striker, the mold is carefully raised, leaving the adobe to diy for a few days, when it is turned to expose the other side. A few weeks of ADVICE-BOAT. 16 ADZE. favorable wpather complete the drying. It is a cliea[) material ami easily built up. It does not ap- pear likely ever to beeome a favorite mode of build- ing in tliose puts of the United States which are at present most tliickly populated. It will not do to make too gemr.d a statement in a countiy whose climate \"ari<'s lictween Ala.ska and Mexico. Ad-vice'-boat. A fast-sailing vessel used for reconnoitei-ing. First used, say the authorities, in spying the operations of the French Heet in Brest, previous to llie battle of La Hogue, 1692. Of course Tliemistocles and the consul Caius Duilius never had any light amphiprora; to "overhaul" the Per- si ms or the Carthaginians, " and when found make note on." Adze. The adze is a very ancient tool, and has a curved blade whose edge is at right angles to the handle ; ditlVring from the a:;e, in which the blade is parallel to the handle. The forms and sizes dill'er Fig. 35. with the character of the work, and in some cases the bit is gonge-sliaped in addition to its curve in the plane of its motion. It is swung in a path of about the same curvature as the blade, the shoulder- joint being the center of motion, and the entire arm and tool forming, as it were, an inflexible i-adius. The above cut from HoltzajifTel gives an idea of the presentation to their work of va- rious wood-cutting tools, a a represent the axe or hatchet, with two bevels ; 6, the brtjad-axe, or sin- gle-bevelled axe ; c, the adze ; rf, the In- dian angidar-bitted adze ; e, the chisel ; /, the mode of pres- entation of a metal- cutting tool, intro- duced for the sake of comparison. Fig. 36 is the modern adze. The adzes of ancient Egypt were of different forms ; Adze. Egyptian Adze. (Thebes.) tlie blade generally the edges curved or straight, straight. - The ligures in the accompanying cut are from a building in Thebes ; one is holding a carriage-pole or tongue, while the other is dressing it to shape with an adze. In the other illustration the blade of the adze is shown confined by a band or strap to the helve. The Fig. 38. Egyptian Adze. (Thebes.) adzeappears often in the Egyptian painting and sculp- ture, and was tlie principal tool in ancient Egypt for fashioning articles of wood. Its blade was of bronze and the handle of tamarisk. The Koinan adze (afcia.) is shown on many ancient monuments. Some have a rounded edge, some a straight. It was then, as now, a ship-builder's tool. The acisi-uhis had a similar rounded head, but was a stone-mason's tool, having a square face and point- ed peen. Among many of the West India Islanders adzes and axes of shell were used. When it was procurable Fig. 39. they were made of flint ; this was worked into the shape of a tool and attaclied by sinews or cords to a helve, or fastened to a withe (see Axe), or, as in Figs. 39, 40, the cutting material of shell, flint, or obsidian was lashed to a stock. Metal super- seded the other materials in most parts of the world, but < many barbarous nations of America and Polynesia yet make their weapons of the material generally discarded at a very distant date in the Old World. Fig. 39 represents three stone adzes of the South Sou ih- Pacific Art:, .EOLIAN ATTACHMENT. 1/ .EOLIPILE. Pacific, and Fig. 40 a stone adze of the Chalam Indians, who oc- cupy the shores of Puget Sound. It suggests the most ancient form of the tool, employed especially for digging out the canoes from the solid log. These canoes were ^ common at a period before the discovery of iron in Europe, and their remains are there found as- sociated with the implements of the stone and bronze ages. The stone adze of the Tahitians, when visited by Captain Cuok, was simUar to those represented in Fig. 39. Large ones for cutting down trees weighed from six to seven pounds ; smaller ones, for carving, but a few ounces. All of them needed continual sharpening, for which purpose a stone was kept in readiness. Adzes are known as Flat, when the blade has a straight edge ; Rounding, when the edge is curved ; Kotchiny, with a straight blade and straight edge. .Sj-oll-an. A contrivance attached to pianos by which a wind instrument may be introduced as an accessory at the pleasure of the performer, air being supplif;! hv a bellows worked by a pedal. iE-o'li-au Harp. A specit-s of musical instru- ment, the sounds of which are produced by currents of air passing over its strings, which are commonly fifteen in number. Its principle may be familia,rly rig. 41. Chalam Adze. Fig. 42. .^olian Harp. shown on a large scale by the action of the tele- graph wires stretched from one pole to another. On a windy day especially these will be found, by any one stationed near, to emit musical tones rising and falling in proportion to the strength of the wind, and more or less grave in proportion to the tension of the wires. Were the number of wires increased, and their length and tension properly varied, these would constitute a perfect Ji^olian. A common mode of construction is to make a box of thin wood and of suitable length, to set beneath a window-sash. It may be five or six inches in width and depth. At one end of the box are pins equal in number to the strings employed, and at the other as many pegs ; the strings, be- ing made fast to the pins at one end, are tuned by turning the pegs at the other. The box is open on the sides presented towards the room and to the exterior air, and the strings are sounded by the passage of the air througli the box. Catgut is usually employed for the strings. It is supposed to have been invented by John J. Schnell, musical-instrument maker to the Countess d'Artois. It was suggested by the ^^bration of the strings of a harp placed in a breezy situation. Exposed for sale in 1789 under the name of Ancmo Ckordc. 2 Its use was rerived by Kircher. One of the Talmuds says that the harp of David sounded when the north-wind blew on it, and it has been suggested that he had an ^Eolian, as we understand it. The sounding of his harp by a gust of wind would be nothing extraordinary if it stood near his north window, which was probably open for air and chosen for its coolness and shade in the climate of Judaea. David wrote a good deal in praise of shade and cool drink. iB-o-li'na. [^.Uitsic.) A modification of the accor- dcon, liy Wlieatstone, leading to the concertina. .31-ol'i-pile. Was invented or first described by Hero, of Alexandria. It was a rotary engine, in which steam issued from the ends of bent arms and by reaction rotated the hol- low shaft or sphere to which the arms were attaclied. Hero's engine revolved in the Serapion about 150 B. C, and many applica- tions for patents in the^ United States and other countries have been made for the same device within a few years past. Invent- ors seem loth to give np this simplest fonn of engine, but it is not probable that it will ever prove a useful or economical one. The above cut is copied from Hero's "Spiritalia," edited by Woodcroft, of London. See Ste.\m- Engise. Ely's ^Eolipile, 1S67, is adapted for rotating a toy. It is poised with its boiler on a central verti- cal pivot, and is connected by a band with the shaft on whose platfomi the toys are displayed. A more serious attempt at applj-ing the principle of the »Eoli]iile is Banta's Kotarj- Steam-Engine, May 28, 1867. The hollow amis rotate in closed cylinders, and their shafts are so connected as to be continuous, the packing of the series being per- fonned at one operation. The steam passes in at the axis of each, and issues at a tangent, driving the wheel by reaction. It is attempted to obtain the use of the steam in a nimiber of successive chambers, in apparent for- getfulness of the loss by back-pressure. The steam enters at the left, and, issuing from one pair of arms, escapes into the fii-st chamber ; from thence it passes to the second vhed, so called, and emerges into the second chamber, and so on. The hubs of the ichcelsme clutched together, so that their ciuuu- Fig. 43. Heroes Steam-Eti^ne. Ely's JEoll[>ile. COLOPHON. 18 AERATOR. Fig. 44 Untary Steam-En:; lative effect is eventu.ally utilized upon the main shaft, on whieli is tlie pinion. See Reaction Stk.vm-Enoinh. .Sl-ol'o-phon. The serapliine ; the predecessor of thi' iiiilc.ili'un and parlor organ. .S'o-lus. .\ small ventilating machine for renevv- iiij,' till' air of apartments. Aer-a'tor. 1. An apparatus for making aerated waters. These consist simply of pure water im- pregnated either naturally or artificially with gases, and are used largely, when combined with vegetable acids and sugar, as refreshing refrigerating beverages in warm weather, and in medical practice during feverish conditions. The insipid taste of melted snow or rain-water is chiefly due to the small quan- tities of gases therein contained ; but when such water has come in contact with the atmospliere by trickling down a ledge of rocks, and rushing along a boiling, rapid stream, or being dashed to and fro by the wimls, it absorbs the gases from the air and is naturally aerated. Ebullition dissipates the gases contained in spring-water, rendering it as flat and insipid to the taste as before it was aerated. The waters of many mineral-springs are aerated in a natu- ral way by the gases arising from the decomposition of minerals washed together from their subterranean beds. The first attempt to prepare artificial aerated waters was made by JI. Venel by dissolving in a pint of water two drachms of fossil alkali to which he added an equal quantity of nuiriatic acid. He used a vessel with a narrow neck to prevent the escape of gas, de]iositing the ingredients in such a manner that they would not communicate with each other until afti-r the vessel was corked. In this case the gas evolved in a vial nearly full and closely corked snlfers such a degree of conpression as to greatly promote its combination with the water. M. Venel sipposed that the real ingredient to which it owed thcise qualities was common air. Two memoirs of Ins expiM-iments were read before the Royal Academy of Sciences in 1750. Dr. Priestley greatly improved upon the discoveries made by Venel and others, and in 1767 eontrivcil an easy method of impregnating water with the principle then dmiomiiiated " fi.xeil air," by ]ilacing shallow pans of water near the sur- face of the fermenting vessels of a breweiy, wliich in a few ho;irs became jileasantly impregnated with the escaping gas. He foiinil upon experiment that the impregnation was accelei-ated liy pouring the water from one vessel into another ; but it did not occur to him till the year 1772 that tliis could be effected by the gases dislodged from dei-oniposing chalk and other calcareous substam^es confineil in an air-tight vessel. Dr. John North's apparatus for impregnat- ing water with carbonic acid was invented in 1775. Between the years isn? and 1852 thirty-one Eng- lish patents were granted for ajiiuiratus anil methods for prei>aring aemti'd water, and fifteen patents for vesscds to hold such waters, and for methods for bottling. The most common beverage is Carbonic Acid Il^ater, generally spoken of as soda-water, though it .seldom contains any soda. H is pre- pared in large quantities by placing whiting, chalk, or marble-iUist in an air-tight, lead-lined vessel with water and sulphuric, acid. Tlu^ sulphuric acid com- bines with the lime to form sulphate of lime (jilas- ter of Paris), and carbonic acid is evolved as gas. The latter is received in a reservoir, and is after- wards forced into water agitated by machinery so that the latter absorbs about Ave tunes its own vol- ume of the gas. The water then constitutes a brisk sparkling licjuid, with a i)ungent but pleasant acid- idous taste. It may be prepared on a small scale, for family and medical pui-poses, by using the appa- ratus known as the Gazogene or Seitzogene. Till' complete apparatus is shown in Fig. 45, and also tlie separated parts. The lower globe is filled with water by means of the long funnel, and then the tube is closed by the stopper, and the powders, consisting of bicarbonate of soda and tartaric acid, are then placed in the upper globe by means of the small Innnel. The stopper is then withdrawn, and the long tube is inserted and screwed closely Fig. 45. Fig. 46. Portable Soda-Water Apparatus. down. The apparatus is then inclined so that the upper globe is about one thii'd filled with water, then placed erect and allowed to stand two hours. If the screw stopcock at the top be opened, the carbonated water will flow out readily into any vessel ji, placed to receive it. Occasionally ife bisulphate of potash is used in- Jji stead of tartaric acid, to save the ^^s3 ex]>ensc of the latter. ^^^Sl Tin* de^*ices which are ordinarily J_i][f called Sodn- Water .-Ipjiaralus, or Snflfi-Founiains, are those used in drawing the beverage and mingling it with the flavoring syrups, etc. / See SdDA-FouNrAiN. In the bottle for aerated liquids, patented by Wahkeu, March 18, 18i)2, the spout of the metallic fountaiii-heacl is lined with glass to keep tlie liquid from contact with the metal. The shoulder on the top edge of the neck, the alternate grooves, and the I'idges on the neck „v,rA-,T'.< Bnttle for are used to strengthen the attach- Aerated Liquids. AERATOR. 19 AERATOR. ment of the metallic cap to wliich the fouutain-hcad is screwed. In Pilitt's ajiparatus lor aerat- ing liquids. September 10, 1867, the top of the aeid-holder c and the pipe s in whicli the plug-rod moves, preserves an equiliuiium of jiressiire, so as to prevent the acid from rising higher in the pipe s than the level of the acid in tile acid-holder the plunger li.a.s a concavity wliieh i by which means the brass-work of the stulhug-box is PratVs AiratoT. Fig. 48. carrn^s down the air ; tlie latter is expelled as the plunger reaches the convex bottom, and is driven through the holes in the tube and disseminated through the liquid in the outer vessel. Wkcjlone, August 14, 18G6. The tube is introduced through the cork ; the liquid enters holes at its lower end, ami is discharged at the goose-neck, when the stop- cock is opened. The bottle may be charged by means of an aux- iliary tube, also passing through the cork, and either removed or closed when the bottle is filled with the aerated liquid. The liquid contents of these bottles may be aerated by means of a simple air- pump placed in temporary connection with the tube when the eduction nozzle is removed ; or chemicals may be intro- duced whose reaction liberates gas when they meet in solution. The aeration of sparkling champagne and Catawba is pi'oduced by adding a .small amount of white sugar to the wine in bottling, the slight fermentation eliminating alcohol therefrom and liberating carbonic acid gas. The efl'ervescing drinks, .such as ginger-beer, are also dependent for their ebullition upon the fermentation of the ingredients and the development of the same gas. Carbonic acid, in moderate quantities, has a very salutary effect upon the stomach, while it is so fatal I when breathed into the lungs. As the Soda-Wajer " ^"'^'' 'I'^iip " or " choke damp " of the BoMt. miner, it has often killed those who < survived the explosion of the carbureted hydrogen. At the Black Hole, near Calcutta, it killed one hundred and twenty-four persons who were confined in a room eighteen feet square by order of Dowlah, Viceroy of Bengal, June 2IJ, 1756. As a gaseous result of the combustion of carbon, — as of charcoal, for instance, — it has destroyed the lives of many who have gone to sleep in ill-ventilated looms. Machines are made on a large scale for charging soda-fountains. C'amei!On'.s aerator has a gas-generator a made of cast-iron, lined with sheet-lead to l)revent the action of the sulphuric acid upon the iron. The vessel contains fifteen gallons, and is partially filled with water and whiting or other carbonate of lime. The agitator 6 is also covered with sheet-lead, and its stem passes through a stuffiug-box c, at the top of the vessel. The acid-holder c is formed of lead, and has a capacity of two gallons, and is partially tilled with oil of vitriol. The acid is kept from running down into the generator by means of the conical ]ilng/, which fits into a conica' seat in the leaden pipe i/. This plug is attached to a rod, and moves up and down through the stutfiug-box h, and is prevented from turning round by means of a pin /•, mov- ing in a slit in the bridle I ; the screw-init is riveted loosely into the top of the bridle. The pipe iiy which forms a communication between jireserved liom injury. To prevent any of the sul- phuric acid from being carried over by the etferves- cence, an intermediate vessel o, containing about three gallons, is foimed of lead or lined with that metal. The interun-diate vessel is filled with water above the eduction-pipe from the generator a. The impregnator r holds about sixteen gallons, and is made of cast-iron lined with lead, or of tin-lined copper, and the agitator m is covered with lead or is made of wood. The impregnator is filled to the dotted line with water, to which, in making saline waters, the proper projiortion of »esqui- carbonate of soda, carbonate of magnesia, or other ingredients is added. For the ordinary soda-water no medicament is add- ed. A pressure-gauge t is connected by a leaden pipe. The operation is as follows : — By turning the nut in the pdug is raised, and acid is allowed to run into the generator «, when it acts ujjon the carbonate, disengaging the carbonic acid gas in quantity proportioned to the amount of acid admitted. The plug is again lowered when the as- certained proper amount has entered the generator. The gas passes by the intermediate vessel into the impregnator v, wliere it is absorbed by the water. The aerated water is drawn otf from the impreg- nator into glass bottles, and tightly corked ; or is removed and placed in connection with the ordinary soda-fountain apparatus by which the licjuid is diawn into glasses. Bakkweil's soda-water apparatus (Engli-sh) has the generator and imi>regnator in the same vessel, separated by a diaphragm, and connected by a pipe. CamfroiCs Aijator AKIUAL CAR. 20 AiiUO-STEAM ENGINE. The vosspI is on traiuiioiis, and is o.scillated so as to allow a penduloiis stirrer in the lower vessel tii agitate the solution of the earbonate of lime. The gas jnisses to the upper chamber, where it performs a cireuitous course in tlu* water whicli absorbs it. •Itlier apparatus depends upon me- chanical nu'ans for injecting the gas into the water by means of a pump or syringe. Many other de- vices might be cited, but tliey con- tain substantially the same parts un- der modihed ar- rangements, — a generator with a means for admit- ting the acid, a con- ductor for tile gas, andan im])regnatov in which the water is permeated by the Apparatrnfcr bottling at the Spring. gas evolved. TllOM.^s's apparatus for bottling mineral waters, June 18, 1S67, is applied directly at the spring. The water is drawn from a considerable depth through a pipe let down in the spring ; a perfo- rated plate of glass is placed in the water below the mouth of the tube, and jets of gas from a reservoij' are discharged below the plate. The object is to charge mineral-water with gas, or to add an extra supply of gas thereto. 2. A contrivance for fumigating grain in bulk, to destroy fungi and insects. Kg. 51. Ftmtaine^s Atrial RaiUvny. A-e'ri-al Car. A ear adapted for traveling in the air. The name is somewhat loosely applied, and may mean one of thr<^e things : — ■ 1. The basket or receptacle of a balloon. 2. A ear whosc^ weight is partially or entirely counterbalanced by a balloon, and which travels on wires by means of driven wheels. See uext article. 3. A car on an idi'vated railway. A-e'ri-al Rail'way. An attempt to govern the balloon or aerostat by guiding rails or wires stretched between posts. Foxtaine'.s Aerial Railway, Febi-uary 5, 1867, may be taken as a .sample. The weight of the car is counterbalanced by an attached balloon. The cigar-shaped car is driven by steam, the deeply indented side-wdleels travelling up- on wires which rest upon brackets whose flanges pro- ject into the circumferential depressions in thewheels. Tile wire-way supported on posts has been adopted for carrying freiglit. Sei- Wii:k-way. A'e-ro-hydro-dy-nam'ic "Wheel. A mode of transmitting power to great distances proposed by a Belgian engineer, Mr. t'alles. The jdan of Jlr. Calles is to make use of air under a certain degree of compression as the vehiide of the force to be trans- mitted, not by accumulating the air thus employed in reservoirs, but by driving it, by tlu^ operation of the original motor, directly into a tube extending to the point of hual application, w'here it is to be dis- charged beneath a wheel submerged in water, which it is to turn by its ascensional force. See AlR AS A ilr.AXS OF TIIANSMITTING PoWER. A'er-om'e-ter. An instrument invented by Dr. M. Hall, Inr a>y means of racks and pinions. They are ground to their seats so as to make air-tight joints, and during the wliole time the engine is in operation the coal-hopjier is kept closed by one or other of these valves. In kin- dling the fire the valves o and p are both opened, lighted kindling is dropped through the chute, and then a quantity of fuel. The valves are then closed, the blower started. When the engine is set to work, it forces air into the fui-uace both above and below the fuel at each stroke, which, having no vent to escape but at the valve A, accumulates in the fur- nace until its pressure somewhat exceeds that of the steam upon the valve li, when it lifts the valve, and, rising up through the water, mixes with the steam, and passes along with it to the engines. / is a slider, by opening which the ashes from the funiace can be withdrawn ; when this is requisite the dara- lK>rs//must be firet closed, v is the blow-otf cock, by which the water can be discharged from the boiler when required, and ;;■ is a hole covered by a door for removing any mud which may have accu- mulated. At * is a glass gage to show the height of the water in the boiler, and at »/ is a glass eye- piece through which the state of the fire can be ascertained. 2 is the man-hole of the boiler. William Mont. Stoum'.s experiments in com- bined air and steam covered the jieriod 1851 - 55, and perhaps later. His Cloud Engine, in which steam and air, in a condition resembling fog, were used to projiel a piston, was exhibited at the fair of the American Institute, New York, in 1S55. The ma- chine appears to have failed to realize the expecta- Fig. 53. Tanker's Steam- Generator. AERO-STEAM ENGINE. 22 AERO-STEAM ENGINE. tions of the inventor. Tlicre wa.s a lack of ailjust- ment .sonu'wliere, it may be supposed, but the end is not yet. Ill A\ AsiinuRN's Air- Heater and Steam-Generator, Unit.'d States I'atent, September .'J, lS(i.'j, the air is al.so intiochiced under pressure into the I'uniaee, and then passed througli a eleunsiny-tank liefore lieiug added to the steam evolved in tlie coil of pipe wliich constitutes the steani-f;euerator. In this ai>pai'atus full saturation is obtained. See illustration in AlK En(!Ink. Stii.i.m.vn'.s Hot Air and Steam Generator, August 9, 1804, has also the eombiiiatioii of air and steam. BlcKKi)Ul>'.s I'atent, June (J, 1SG5, may also be examined in this connection. In Tanoich's Steam Generator, December 4, 1866, the air is injected into the jiipcs H and / by means of a foi'ce-pinnii, and after being heated while passing through the convolutions of tlie pipes F anil J, is forced into the lioiler by nipples, as sliciwn at K. In Tai;i:'s Aero-Steam Engine, 18(J7, tlie air is heated within the furnace, and is thence forced through the pipe into the steam-chest, where it min- gles with the steam coming through the pijie ; and the mixture of steam and hot air is by means of a slide-valve admitted alternately above and below the piston in the ordinuiy way, so as to produce the usual reciprocating motion. Waksop's Engine (English), 1869, is started by steam in the ordinary maimer. A single-acting air- pump, worked from the crank shaft, compresses air to a little more than the boik'r pressure ; the air then passes tlirough a long circuit of straight and coiled Jiipe, which traverses the exhaust-pipe, makes several spiral coils in the chimney, then descends at one side of the lire-box, is exjiosed to the full tire, and finally passes by a valved opening into the boiler at the bottom of the water-space. Warsop's object is similar to that of several of his predecessors, to make steam assist the expansive force of air, and to avoid the difficulties of lubrication incident to the use of hot air alone. He attempts to obtain the maximmn etlect from nnxed air and Fig. 64. lVnrsop\'i AlfTO- t^eam Engine Hoiler, steam by instituting a certain approved proportion between tlie two. It is ijiiite probable that such a ratio may be found, and that it may secure substan- tial economical advantages. The ]ii]ie .;, thi'oiigli which the air is forced into the bnih'T liy the action of tlie air-]>unip, is of iron, and is 1|^^ inches in diameter outside, and \\ inch bore. Ou leaving the puni]i the pipe is tirst led to the heater Ji, shown on the left of the engraving, wherein it is exposed to the exhaust .steam. The heater consists, as will b(^ seen, of a east-iron cylin- drical vessel placed in a vertical position and pro- vided with two branches — one near tie- liottnm and the other near the toji — through wiiicli tlic exhaust steam rcsjicctively enters and escapes from the cas- ing. At the top of the lieater is jilaced a small cylindrical tank 1), exposed at the bottom and sides to the exhaust steam, and perforated around the np]ier part of the .sides, so that in the event of its reci'iving an exi-ess of water the latter may oveiHow and fall to the bottom of the heater. Thiough a stulling-box at the bottom of the tank there passes a tube with a rose E at the lower end, this tube being carried by a lloat F, which swims in the water at the bottom of the heater, as shown, and, by means of a cord ]iassing I'rom the top of the tube, works a cock G, which regulates the supjily of water to the tank at the toji of the lieater. The air-pipe ..*/, after leaving the heater just described, passes along the exhaust-pipe C to the chinmey fl, and, descending the latter spirally, as shown, jiasses into the Hue beneath the boiler. Here it is led backw'ard and forward, as shown in the plan, and after making several convolutions in the smoke-box, is led back to the front of the boiler, where it communicates witli a valve-box, contain- ing an ordinary, light clack-valve. The object of this valve is to prevent water from entering the air- )iipe when the engine is stopped. From the valve- box a pipe is led down within the boiler to the bottom of the latter, this jiipe being perforated at intervals on the upper side. The perlbrations are placed closer together at the farther end of the pipe than they are at the end at which the air en- ters, and by this means an eipiable distribution of the air at tlie differ- ent parts of the boiler is insured. The lengths of tbe various por- tions of the air- )ii])e are as fol- lows : III feed- water heater, 12 feet ; in exhaust- pipe, 13 feet 6 inches ; in chim- ney and tines, in- cluding coils in smoke - box and under lioiler, 58 feet ; total, 83 feet 6 inches. The total external sur- fai'c exposed by this pijic is thus about 36J square fei't. The principal dimensions of the J^THIOPS MINERAL. 23 AGRICULTURAL IMPLEMENTS. boiler are as follows ; Length, 8 feet ; diameter of sliell, 3 feet 6 inches ; lUanieter of fire-box flue, 2 feet 2 inches ; length of fire-box and combustion- chamber, 5 feet ; and length of tubes, 3 feet. Tlie tubes are 41 in number, most of tliem being 2§ inches, and some of them 2-j^g inches diameter. The total effective heating surlace exposed by the boiler is about 13" sijuai'e feet. .ZB'thi-ops Min'er-aL A compound of sulphur and nu'rcury, so called on account of its blackness. Tlie black sulphuret of mercury, formed by tritu- rating together meri'ury and sulphur until the two combine and form a black powi.l«-r. .ai'thri- o - scope. Fig. 56. .Mtbrioscope, An instrument for measuring the degrees of cold arising from exposure under dif- ferentconditions of the sky. A highly pol- ished metallic cup or concave mirror is jilaced upon a pedestal of convenient higlit, and a differential ther- mometer is placed within it so that one of the bulbs of the thermometer shall be exactly in one focus of the mirror ; the other bulb being not in either focus is not af- fected by the pulsa- tions, the effects of which on the cup are concentrated upon the first bulb, the air in ■nhich being suddenly eonti'acted upon its exjiosure to a clear sky, the liijuid in that branch of the .stem is caused to rise. The cup is kejit covered with a me- tallic plate, exce]it at the moments of oliservarion. Af fi-nage. The act of refining or making purer, as the aftinage of metals. Aft'er-rake. The part of the stern which over- hangs the keel. Aft'er-sail. {Xantkni.) A sail whose center of effort is abaft the general center of effort of all the sails. Head-sails are relatively before the said point, and by means of these head and after sails a shi]> may be maneuvred. Aft'er-timTDers. (Shiphuildi'ng.) 1. Radiating eant-franies, abaft the fashion-])ieces and below the wing-transom, stejtjied piartiy on the dead-\\'ood and partly on stepping- pieces bolted to the sides of the inner stern-post. 2. Those abaft the midship section. Ag'a-ba'nee. (Fubric.) Cotton embroidered with silk, made in .\leppo. Ag'ate. (Vrinlhiq.) 1. A size of type between Pearl and Nonpareil ; called liuby in England. renrl. A (rate, or Ruby. Nonpareil. 2. The draw-plate of the gold-wire drawei-s ; so called because the drilled eye is an agate. 3. The pivotal cup of the compass-card. Age'ing. {Poffcrii.) The storage of prepared clay, to allow it time to fei-ment and rijien before using. The slip, consisting of levigated clay and flint, is run in a thin solution through sieves and brought to a creamy consistence. This is boiled ilown to give it more solidity, and is then stored away, sometimes for years, being occasionally cut out in chunks and slapped to expel air and develop the pla.sticity. During the aqeing process a slight fermentation occurs, carbonic a id and sulphureted hydrogen are disengaged, and the mass is im]u-oved in texture and ijuality. The clay is thus allowed to temper in cellars or under cover, sometimes for several years. In China, a potter prepares the clay for the suc- ceeding generation wliile working "up that be- queathed to him by his ancestors. iJI'iiie and Liquors.) Devices for this pui-pose subject the licpiid to heat and agitation ; some of them using the combined action oi' heat, electricity, and attrition. See Wixe-aoeixg Api'ai!.\tus. {Calico PrinJim/.) The exposure of printed cali- coes in a sufficiently moist and warm air to allow the colors to permeate and mature. An apparatus was patented by Thorn, England, for appl}-ing air loaded with moisture of a given temperature to the jirinted fabric, which is then folded aud allowed to rest for a few hours in that condition. A-gist'meat. A dik- or embankment to prevent the overflow of land aliutting upon a stream or the sea. Ag'i-ta'tor. A rotating beater or armed shaft for mixing and disturbing articles mechanically sus- pended in water, such as The pulp in the stuff-chest of a paper-machine. The mash in the nia.sh-tub of a brewery. The mixture of starch, sugar, etc., and water, in the washing jirocess of starch-making. Ag'ri-cult'ur-al Im'ple-ments. These are treated, .as fully as the limits will peiiuit, under their respective heads ; it is needless to repeat here the history of their- progressive development or the order of their succession. See the followiug, under theii- respective heads : — AcniCULTUKAL \XD Hr.SBAN-Dr.Y iMrLEMF.XTS, ETC. Abenincator. Animal-clutch Animal-poke. Apiary. Atmospheric churn Auger. Earth-boring. Aveler. Averuncator. Awner. Bagasse-dryer. Bag-fastener. Bag-holder. Bag-tie. Bale-tie. Baling-press. Band for baling. Band for Innding grain. Band-cutting machine. Barking-tools. Bailey-chumper. Barley-fork. Barley-huUer. Bar-.share plow. Basket. Bean-harvester. Bean-mill. Bee-feeder. Bee-fumigator. Beehive. Beehive, swarm-indicator Cattle-pump. for Cattle-stall. Bee-tax. Cattle-tie. Belly-roll. Caving-rake. Bill. Chaff-cutter. Bill-hook. Chee.se-cutter. Binder. Cheese-hoo|i. Binding attachment for harvesters. Binot. Blade. Bob-sled. Bog-cutting plow. Bott-hamraer. Bow. Ox Braking-machine. Branding-tool. Breast-plow. Brier-scytl-.e. Broach. Broadcast-sower. Brui.sing-machine. Bnrsh-pullei-. Bugg\--culti vator. Bull-nose ring. Bush-harrow. Bush-scythe. Butter-mold. Butter-tongs. Butter-worker. Calorifier. Cane-harvester. Cane-scraper. Cane-stripper. Cattle-feeder. Cattle-leader. AGRICULTURAL IMPLEMENTS. 24 AGRICULTURAL IMPLEMENTS. Clieese-knife. Clmi'se-.slidf. Checsu-vat. Chessel. Chicken-raisiug appara- tus. Chopness. Clioppcr. Churn. Chuni-clasher. Cliuru-iiower. Cidcr-iuill. Ciiler-jtress. Clevis. Clod-cnislipr • Clover-harvester. Clover-huller. Clover-thrasher. Clutch for catching ani- mals. Cock le-separator. Colter. Corn-coverer. Corn-crib. Corn-cultivator. Corn-cutter. Corn-harp. Corn-harvester. Corn-huUer. Coni-lnisker. Coni-husk splitter. Corn-knife. Corn-planter. Corn-plow. Corn-row marker. Corn-sheller. Corn-shocking machine. Corn-stalk cutter. Corn-stripping knife. Cotton-brush chopper. Cotton-chopper. Cotton-cultivator. Cotton-gin. Cotton-picker. Cotton-pross. Cotton-scraper. Cotton-seed cleaner. Cotton-seed planter. Cotton-.seeJ preparing. Cotton-topper. Cow-milkor. Cradle. Cranberry-gatherer. Cream slice. C'rooni. Cultivator. Cultivator plow. Curcvilio-trap. Curd-breaker. Curd-cutter. Cutter. Harvester Cutting-box. Diamond plow. Dibble. D ibhl ing-machine. Digger. Diggi iig-machine. Ditching-machine. Ditching-plow. Ditching- tools. Double j>low. Douljle-moUl-board plow. Double shovel plow. Drag. Draining-plow. Drill. Barrow. Drill. Grain. Drill. Harrow. Dropper. Dumping-reel. Dunji-fork. Dung-hook. Edging shears. Egg-liatching apparatus. E.\l>anding plow. Fanuing-mill. Feed-bag. Feed-eutter. Feed-rack. Fence. Fence-jack. Fence-post. Fence-])ost driver. Fertilizer-sower. Fiddle. Finger. Flail. Flnx-brake. Flax-puller. Flax-scutcher. Flax-thrasher. Fla.x-washer. Fleece-folder. Flower-pot. Fork. Fork. Horse hay- Fruit-dryer. Fruit-frame. Frait-gatherer. Fruit-ladder. Fruit-picker. Fruit-jireserviug house. Fruit-])ress. Funiigator. Furrowing-plow. Gage wheel. Gallows. Gang-eultivator. Gang-plow. Garden ladder. Garden shears. Garden syringe. Garlicseparator. Gate. Gate-post. Gaveling attachment for harvesters. Grafting-chisel. Grain-binder. Grain-bruiser. Grain-cleaner. Grain-conveyer. Grain-cradle. Grain-drill. Grain-dryer. Grain-folk. Grain-harvester. Grain-rake. Grain-sacker. Grain-screen. Grain-separator. Grain-shovel. Grain-thrasher. Grain-wheel. Graip. Granary. Oriipery. Grape-trellis. Grass-harvester. Grass-seed separator. Ground auger. Grubber. Grubbing-axe. Grubbing-hoe. Guard hnger. Hackling-machine. Hair-clipping shears. Hand-cultivator. Hand-planter. Harle. Harrow. Harvester rake. Harvesting-machine. Hasp. Hay-batul machine. Hay-cutter. Hay-fork. Hay-knife. Hay-loailer. Hay-press. Hay-rack. Hay-rake. Hay-raker and cocker. Hay-spreader. Hay-stacker. Hay-tedder. Hay-unloader. Heading-machine. Hedge-planter. Hedge-clipper. Hedge-shears. Hedging tools. Hemp-brake. Hemp-harvester. Hen's-nest. Hink. Hive. Hoe. Hoe. Horse. Hoe-plow. Hog-elevator. Hog-hook. Hog-nose-tiimmer. Hog-ring. Hog-scalding tub. Honey-strainer. Hoji-frame. Hopple. Hop-pole. Hop-press. Hor.se hay-fork. Horse-hoe. Horse-power. Horse-rake. Horseshoe. Hot-bed frame. Humbug. Hummeling machine. Hurdle. Husker. Husking-peg. Incubator. Insect-exterminator. Insect trap. Jum])er. Kibbling-niacliine. Lactometer. Lactoscope. Ladder. Land-paring machine. Lap-ring. Lard-cutter. Laril-renderer. Lawn-mower. Layering implements. Leveler. Lime-spreader. Manger. Manure-drag. Manure-drill. Liquid Manure-fork. Manure-hook Manure-loader. JIanure-sprcader. Marking-jilow. Mattock. Maul. Milk-can. Milk-cooler. Milking apparatus. Milk-rack. Milk-shelf. Milk-strainer. Milk-vat. Mole-plow. Mollebart. Moth-trap. Mower. Muck -fork. Muck-rake. Muzzle. Nib. Osier-peeler. Ox-.shoe. Ox-yoke. (See Yoke.) Paring- plow. Peanut-digger. Pea-rake. Peat-macliine. Peeling-iron. Pickaxe. Picker. Cotton Picket. Pitchfork. Planter. Plow (varieties ; see Plow). Plow-cleaner. Poke. Portable fence. Post-auger. Post-driver. ■ Post-liole borer. Post-hole digger. Post-jack. Post-puller. Potato-digger. Potato-hook. Potato-planter. Potato-scoop. Potato-separator. Poultry-feeder. Powder-blower. Prairie-plow. Propaga t i ng-box. Pruning-shears. Pruning-tools. Rack. Rake. Raker and loader. Rake-harvester. Rake. Horse hay. Reaper. Reaping-hook. Reaping-machine. Reel. Harvester Reversible plow, AGRICULTURAL STEAM-ENGINE. ZO AIE APPLIANCES. Kice-eleaner. Riddle. Ridging-plow. Ripple. Roller. Land Root-bruiser. Root-cutter. Root-digger. Root-gi'inder. Root- washer. Rotary cultivator. Rotary digger. Rotary harrow. Rotary plow. Rotary spader. Rudder. Sap-bucket. Sap-bucket hook. Sap-spile. Scarifier. Scoop. Scraper. Scuffle-hoe. Scuffler. Scythe. Seed-drill. SeetHng-maeliine. Seeding-plow. Seed-planter. Seed-sower. Separator. Share. Shears. Pruning Shears. Sheep. Sheep-dipping apparatus. Sheep-foot trimmer. Sheep-holder. Sheep-rack. Sheep-shearing machine. •Sheep-shearing table. Sheep-shears. Sheep- washing apparatus. Slieller. Com Shovel. Shovel plow. Sickle. Side-hill plow. Single-shovel plow. Skeleton plow. Skid. Skim-colter plow. Skinning apparatus. Slaughtering apparatus. Smoke-house. Smut-machine. Snath. Snouter. Snout-i-ing. Snow-shovel. Sod -cutter. Sod-plow. Sorghum-evaporator, oorghura-stripper. Sower. Spade. Spading-machine. Spud. Stable-cleaner. Stack-borer. Stacker. Stacking derrick. Stack-stand. Staddle. Stalk-cutter. Stalk-puller. Stall. Steam-engine. Agricultu- ral Stcam-jilow. Stock-feeder. Stocks for refractory ani- mals. Stone-boat. Stone-gatherer. Straddle-plow. Straw-carrier. Straw-cutter. Stubble-turner. Stump-extractor. Subsoil plow. Susar-cane jdanter. Sulky plow. Sward-cutter. Swather. Sweet-potato cultivator. Swing-moldboard plow. Swing plow. Tedder. Tether. Thatching. Thistle-digger. Thi-asher. Tobacco-curing apparatus. Tormentor. Track-clearer. Transplanter. Treble-shovel plow. Tree-digger. Tree-protector. Tree-remover. Tree-scraper. Trellis. Trowel. Turf-cutter. Turnip- puller. Turnwrest plow. Vegetable-chopper. Vegetablc-slicer. Vegetable-washer. AVeediug-hoe. Wheel- colter Wheel-cultivator. "VVheel-plow. Whitening-machine. AVillow-peelcr. Winnowiug-machine. Wool-packer. AVool-packing table. AVool-press. Yoke. Ag'ri-cult'ur-al Steam'-en'gine. A steam- engine specitically adapted for use in thrashing and some other fai'm operations. Its principal peculiar- ity consists in compactness and portability. See Por.T.\BLF. Stf.am-E.vgine. Aich's Met'al. An alloy of copper, zinc, and iron, used for guns. Patented in England, Febru- ary 3, 1860, by Johann Aich, Imperial Arsenal, Venice. It is composed as follows : — Copper, . . 60. Zinc, . . 38.125 Iron, . . 1.5 It resembles the Keir metal, English patent, De- cember 10, 1779, which ha.s, — Copper, . . 100 ) ( 100 Zinc, . . 7.'i ■ or, • 80 Iron, . . 10 ) ( . 10 Also the sterro-metal of Rosthorn, Austria, 1S61, which ha.s, — Copper, . . 55.04 \ Tin, . . 0.83 I Zinc, . . 42.36 ( Iron, . . 1.77 ) Austrian navy brass has, — Copper, . . 60. Zinc, . . 38.12 Iron, . . 1.8 Chinese Packfong has, — Copper, . . 40.04 Zinc, . . 25.4 Iron, . . 2.6 Nickel, . . 31.6 57.63 I 0.15 I 40.22 1.86 See Allot. Ai'guille. boring tool A needle. Among masons, a stone- A priming-wire. Aim-front let. A ]>iece of wood hollowed out to tit the muzzle of a gun, so as to make it level with the breech, formerly in use among gunners. Wood- en front-sights on a similar principle are still used on board ship in ease of emergency, as when an acci- dent occurs to the proper metal sights. Air and Steam En'gine. See Aiino-STEAM EXGIXE. Air Appliances and Acetifier. Acoustic instruments. Acoustic telegraph. JEo\vlS. Aerator. Aerial railway. Aero - hydro - dynamic wheel. Aerostat. Aero-steam-engine. Air and steam engine. Air as a means of trans- mitting power. Air as a water-elevator. Air-bath. Air bed and cushion. Air-blast. Air-brick. Air-carbureting. Air-casing. Air-chamber for pumps. Air-com pressing machine. Air-cooling apparatus. Air-cushion for pipes. Air-drain. Air-drill. Air-engine. Air-escape. Air-e.xhauster. Air-filter. Air-fountain. Air-grating. Air-gun. Air-heater. Air-holder. Air-jacket. Maclainery. -\ir-level. Air-lock. Air-machine. Air-meter. Airohydrogen blow-pipe. Airometer. Air-pipe. Air-poise. Air-pressure filter. Air-]iump. Air-regulator Air-scuttle. Air-shaft. Air-spring. Air-stove. Air-thermometer. Air-trap. Air-trunk. Air-tube for convej'ance. Air-valve. Air-vessel. • Anemogi'aph. Anemometer. Anemoscope. Aspirator. Atmospheric alarm. Atmospheric churn. Atmospheric engine. Atmo.spheric governor. Atmospheric hanmier. Atmospheric railway. Atmospheric spring. Atomizer. Auricle. Balloon. Bellows. AIR AS A POWER. 2G AIR AS A POWER. Blast. BliiBt-macliine. Blast-nozzle. Blower. Blowing-machine. BloHini,'-tut)e. Bli)W-iii|)i'. Caloric engine. Captive balloon. Carbonic-aciil engine. Carbureting-niacbine. Car-ventilator. Cold-blast. Coni]>ress«l-air engine. Cu]iiiiiig-|)um]). Cylinder blower. Detonating tube. Dispateh-tube. Diffn»ion-tiibe. Disinfecting ap])aratus. Ear. Artificial Ear cornet. Ear instruments. Ear-tnimpet. Eccentric I'an-blower. Ejector. Eudiometer. Exhaust fan. Fan. Fan-blower. Fanner. Fanning-machiue. Fanning-niill. Fan-ventilator. Fire-extinguisher. Flighter. ' Flying-machine. Foot-t)el!ows. Fumigator. Graduator. Gunpowder engine. Hydrostatic bellows. Inhaler. Insect exterminator. Insufflator. Leech. Artificial Life-preserver. Magdeburg hemispheres. Mulguf. Organ. Parachute. Pneumatic drill. Pneumatic lever. Pneumatic pile. Pneumatic jmmp. Pneumatic railway. Pneumatic spring. Pneumatic trough. Pneumatic tube. Pneumatic tubular dis- patch. Pneumatic valve. Pneumatometer. Punkah. Respirator. Rotary blower. Rotary fan. Sand-bellows. Sand-blower. Screw ventilator. Sirene. Smoke-jack. Sonifer. Sonometer. Sound-board. Speaking-tube. Speaking-trumpet. Spirometer. Stench-trap. Thermometric ventilator. Tonometer. Torricellian vacuum. Trompe. Tuyere. Vacuum apparatus. Vacuum-filter. Vacuum-gage. Vacuum-pan. Vacuum-pump. Vane. Ventilating millstones. Ventilator. Water-bellows. Wind-car. Wind-chest. AVind-cutter. Wind-furnace. Wind-gage. Windmill. Windmill-propeller. Wind-pump. AVind-sail. Wind-trunk. Wind-wheel. Air as a Means of transmitting Power. So far as our information extends, the first person to use compressed air as a means of transmitting power was that ingi/nious Frenchman, Dr. Pa]iin of Blois, about A. D. 1700. We shall have occa- sion to refm- to him in the History of the Steam- Engine. He was the first to apply a piston in the steam-cylinder, and was the inventor of the digester, and the steelyard safety-valve, — the best and sini|ili'st efiVctive form yet devised. Pa]iin usi'd a fall of water to compress air into a cylinder, and led it thence by a pipe a distance of a mile. Having reached its destination, it was em- ployed to drive a piston in a cylinder, the power being intended to work a pump. The distance, the friction, and the leakage were too much for the Doctor, anil the inversicm of the process, making the primaiy engine exhaust instead of condensing, liauipressed air to working-cranes, hoisting-machines, and other machinery. The air was compresseil by an air-pnnip at a central location, and the air conducted by pipes to the cranes and other machinery of a series of docks and warehouses. The same inventor also applied an air-exhaust to raising a tilt-hammer. See At.muspheiuc H.^m- .MKi:. The subjoined cut has a remarkably unpromising look, but must net be condemned because it resem- Fig. 57. Caiies^s Aero-hydro-dynamic Wheel. bles at first sight one attempt at the chimerical and impossible "perpetual motion." It is one mode of transmitting power by means of condensed air. Tlu' following is from the Journal of the Society of (Jerman Engineers, and describes the ajiparatus represented in the cut, the invention of Jl. Calles of Belgium : — "It consists mainly of a wheel adapted with buckets similar to those in an ordinary water-wheel, and completely immersed in a tank filled with water. This wheel carries a toothed inner rim, which works a pinion adapted to the transmission- shaft. " Most transient visitors to the Paris Exposition, as they walkeil past this contrivance, liardly gave it a look, believing that it was the pinion that gave motion to the wheel, and considered it as some .sort of stirring or washing nuichim- ; but the inverse was in reality the case, as it was the immersed wheel which "gave motion to the pinion by the direct action of slightly compressed air. AIR AS A POWER. AIR AS A POWER. "The general disposition of parts will be readily understood by reference to the diagram ; — " The diameter of tlie wlieel exhibited was 9 feet ; its breadth 4i. It carried 30 Imckets, curved in such a manner that 13 of them (ligured to the left) always retained a certain quantitj' of air in their upper portion. " The air was introduced under the bottom of the wheel, tlivough a curved pijie. The air thus blown into the buckets had naturally a tendency to gain the surface of the water witli a force equivalent to the weight of displaced water, and tliis u])ward ten- dency caused the rotation of the xvlieel, and at the same time brought back tlie discliarged buckets successively before the orifice of the tuyere. "The wheel made six revolutions jier minute, so that three buckets were fiUeil with air every second. "The air rushed with a velocity of 32 metres per second through a pipe 0.095 nx-tres in diameter. The quantity discharged was consequently 0.227 cubic metres per second, equivalent to 0.075 cubic metres for each bucket or cell. During every sec- ond of time, 13 buckets were thus partly KUed with air, their total capacity being 0.983 cubic metres. The same bulk of water being displaced, a constant power of approximately 983 kilogrammes, or 2,163 lbs., per second was obtained. "The internal diameter of the wheel being 2. 26 metres, its annular surface 3.05, and its width 1.5, it is readily computed that the 30 buckets occupied a space of 4.585 cubic metres, and that each cell cubed 0.153 cubic metres, — a portion of which space, equivalent to one half, or to 0.075, alone containeil air. "If the application of force be supposed to have been applied at one quarter of the depth of the wdieel under water as an average, then the speed of any point of its surface would have been 2.445 x 6 X w -i- ti0 = 0.77 metres = 30 inches. "Multiplying this speed by the 983 kilogramme- tres, we tind the power transmitted per second to have amounted to 757 kilogi-ammetres. If we de- duct herefrom 20 per cent for losses by friction, reaction of water, etc., there remain 606 kilogiam- metres, or 260,000 foot-pounds, as availalile work- ing-power per minute, — equivalent to an 8-horse power. " The forcing of the air was effected by means of a 9.J-horse steam-engine, — tlie compression of the air being one quarter of an atmosphere. In the exam- ple exhibited, 83 per cent of tlie power of tlie engine was thus transmitted to the wheel, and this through a ]iipe 510 feet long and presenting 14 cUiows. *' The above-described new method of transmission of motion may prove of very great value in many situations where tlie application of belts and shaft- in^', jiarallel motions, such as are used in mines, and other similar contrivances, is impracticable. It might also be apjilied with success to the driving of machinery in cities for the smaller branches of industry, — the compressed air in such a case being conveyed through mains and pipes laid below the sui'face of the streets in the same manner as is at present practised for our water and gas supplies." By reference to Wrr.E Rope, several instances may be found where jiower is transmitted to a dis- tance much lieyond what is possible witli belting or shafting, the ordinary expedients. In one case, at Frankfort on the Main, the power is thus trans- mitted 3,200 feet. In a second case, at Schaflhausen, in Switzerland, the power of a number of turliines, amounting in the aggregate to 600-horse i>ower. is transmitted more than a mile, crossing tlie river Rhine to the place where the power is to be distributed. Machinery in mines and tunnels is frec|Uently driven by the power of compressed air, which is condensed into a reservoir by steam or water power on the surface of the giound, and conducted by pijics to the deep-seated spot where the drill or mining- machine is at work. "At Mont Cenis the air-pipes must be as much as five miles in lengtli, and tlie loss of pressure is not sucli as to impair the working of tlie drills ; hut I am without accurate information as to its extent. At Hoosac they are one and a half miles long, and the lo.ss is two pounds to tlie square inch. At Nesquehoning they are one third of a mile in length, and there is no apjirccialile loss of pressure. In this case the air is worked at about fifty pounds per square inch ; and the difi'erence in jircssure at the steam-valves, when the power is generated, and the air after it is compressed, may be taken at about ten per cent when the best compressors are used. It will then be seen that the loss of power from the friction of the compressing machinery, and from the movement of air in t!ie jiijics, is not of a very serious character, and, if the iii|ies are tight, the pressure is well maintained while the machinery is standing." — Steele. " The compression of the air by which the drills at the Hoosac Tunnel are driven is eticcted at tlie east end of the tunnel by water-power ; four 20-liorse turbines being employed, which operate sixteen air- pum]is, each of 13.i-incli bore and 20-incli stroke. " Tlie air is compressed to 65 pounds to the square inch, or a little over four atmospheres, and con- ducted through an S-inch cast-iron pipe to tlie drills ,nt tlie tunnel heading, wliere branch pipes connect several drill-cylinders witli this 8-iiich pipe. With six of the drills at work and making 250 strokes per minute, the gage on the air-jiipe at the heading of the tunnel shows a pressure of 63 jiounds against 65 pounds at the pump-rooms, one mile and a half distant." "The engineers of the Mont Cenis Tunnel have expressed themselves strongly in favor of the view that the plan is truly economical, and as their experience in the use of this form of applying power has been larger than any which has been el.sewliere enjoyed, their statements ileserve consideration. At the date of the report on the progiess of the work in the tunnel during the year 1803, they were engaged at a distance of nearly two thousand metres from their reservoirs of condensed air, and were driving nine borers with a force of 2J- horse power each. The tube conveying the air to the perfoi-atoi-s was two decimetres (nearly eight inches) in diameter. The air was under a jiressure of six atmospheres, and its velocity in the tube was nine decimetres (three feet) jier second. The trans- mission of the power to this distance, and under these conditions, was attended with no sensible loss. The pressure was not perccjitilily less at the work- ing extremity of the tulie when all the perforators- were in operation than when the machinery was entirely at rest. "A series of ex])eriinents was instituted in 1837, by order of the Italian government, to detcmiine the resistance of tubes to the tlow of air through them. These experiments were made jireviously to the commencement of the work upon the tunnel, and while the feasibility of employing comiiressed air to furnish the inotive-jiower of the boring appa- ratus was considered still questionable. It was tl e aim of the investigation not merely to ascertain tlie absolute loss of force occurring in the transmission of air through tubes of certain particular dimen- sions, but to determine, if possible what are tlie AIR AS A WATER ELEVATOR. 28 AIR AS A WATER ELEVATOR. laws wliioh govern the variations of rpsista;ice, when the velocities of flow and the dianieter.s of the tubes ari^ varied. From tlie results of the e.\- perinients were deduced tlie three conelusions i'ol- lowing, namely, — " 1. The resistanee is directly as the length of the tube. "II. It is directly as the square of the velocity of flow. "III. It is inversely as the diameter of the tube." See licpirrf' of iJr. Barnard, United States Coinntis- sioucr at the Paris Exposition. This great work is hajipily completed. See Tl-Xi\F.L. in the Verpilleux puniji, water is made the means of transmitting power. See FoitcK-PuMr. The transmission of power by means of compressed air has now become an established fact, notwith- standing the clear decision which was rendered against it, from the sui)iiose draws an an- ^'S- 64. nular film of water with it from tlie space A at the bottom of the well. The action is tlie same as in the former case, except that in this the moving fluid is a jet cen- tral to the film of water moved by it. and in tlie preceding cases the air An^er and Crock^'.'i Ejector. and oil were annular adja- cent films. The double set of pipes in the case under consideration and in the next following are not so convenient in shafts of great depth and minimum diameter. McKxiGHT, November 1, 1864. Fig. 63. This is an ejector like the former, but adapted to a position where a lower chamber A is not fatal to its appliciation. The air or steam pipe C B recurves upwardly and pen- etrates the throat of the eduction-pipe D, wlrich the water ascends. While these devices prop- erly belong to Ejectoes, which ai'e considered at Pcfase'» Oil-Sector. AIR AS A "WATER ELEVATOR. 30 AIR-BATH. greiiter length under that title, it will be useful to give a .slight sketch of tlie modes of utilizing the compressed air, the suhjei-t-njatter of this article. The ejectors descriU'd aie direct-acting an, but had been described nearly two thousand years pre- viously by Heio in his " Siiiritalia." It was at- tached by Perrault, in 1684, to the fire-engine {Pompe Portative) of Du- perrier. It is intended toequalize the flow of water from a re- ciprocatingpump. The ac- tion of the pumpbeing intermit- tent, the tendency is pulsative and the delivery in jerks. The body of air confined in the upper part of the chamber forms an elastic cushion against which the water impinges when lifted ; when the pump-piston stops to commence its return move- ment, the air again expands and continues the How of water dur- ing the interval of inaction of the piston ; the valve falls as soon as water ceases to enter the chamber, to ]ire\cnt return of the water by the induction-]'i|ie, when the air i'X)iaiKls. Air'-com-press'ing Ma-chine'. A machine adapted to condense air as a motor, or for ventilation in shafts and mines. For this purpose air is partic- ularly well ada])ted, because its exhaust in the nune shaft or tunnel aff'ords a direct means of ventilation by supply of ^ital air at the point where the work is under way. The works at the Jlont Cenis and Hoosac Tunnels are notable instances of the use of compressed air carried to a great distance. The air- comi)ressing engine of Sommeilleur at Bardonneche worked the rock-drills at the Italian end of the Mont Cenis Tunnel, and was operated by the dis- placement of air from a )jipe liy a heavy column of water obtained from the hills. See Compkessed- Aiii M.^ciirNE ; Tunnel. The escape of steam at the point of work is not so desirable as that of air for two reasons : the condensation of the former prevents its acting to jiroduce an outflow of air to- wards the mouth, as is produced by the escaping and expanding air ; and it only adds to the damp- ness and oliscurity of the usually wet shaft or drift, instead of being a source of supply for breathing, from the healthy region of the exterior air. Many of the devices for merely assisting ventila- tion are no more than blowers (which see), but for use as a njotor a more positive condensation is re- quired. By tlie law of jlariotte, the elastic force of air varies in the ]>roportion of its densit)' ; the great- er the pressure the smaller the volume. Assuming the natural pressure to be 15 pounds to the square Air-Chamber. AIR-COMPRESSING MACHrNE. 32 AIR-COMPRESSING MACHINE. inch, by reduciiif; tlie volume to one half we shall have a pressure of 'M jiounds to the square inch ; to one quarter, CO pounds ; to one tenth, 150 pounds ; to one fortieth, COO jiounds. The stroke of a ]iiston in its cylinder, therefore, if it reduce a bocly of air to one twentieth its oi'igi- nal volume, will subject it to a pressure of 300 pounds to the sciuare inch. The air is generally al- lowed to escape by a valve-way before the ap[iroach- ing piston, and is collected in a reservoir, whence it ])asses to the machinery where its expansive force is to be ajiplied. The circumstances of position and use are so very varied tliat no general statement of its niotle of application will apply. Sometimes it is stored in reservoirs at the point where it is used as a motor or a ventilator. FisK AND Wateu.\i.a.n, January 17, 186.5. The reservoirs for compressed air are located within the mine, ami connci^ted by comparatively large induc- tion-pijics with the air-foreing pump at the mouth of the mine. The object is to e.xert a uniform pressure at the working point, where compressed air is used as a motor, ami to prevent a stopjjage of the ventilation during a temporary stoppage of the com- pressing-eugine at the mouth of the mine. The Fig 70. air by the duct Eto the cylinder f.'. The motion is repeated ; the intervention of the water, as in the last-preceding ease, obviating the necessity for an air- tight packing to the piston. WlLHELM, De- cember 26, 1SG.5. A pump C F, of ordinary construc- tion, is enclosed within a large air- chamber L, wliich has no bottom, but is suspended in an open vessel of wa- ter A, so that the water may ri.se high in the chamber, and Pig. 72. Ransom^s Air-Compressing Pump. when driven back by the force of the air may continue a pressure thereon and thus keep u]> a continuous blast. This may be better adai)ted for a blower, but, by an'anging for a high vertical column of water, it may he applied to mo7'e positive and high- pressure pui-poses. Patrio, April 18, 1S65. This de- ,j|J|vice is intended to he placed at the j! y| foot of a waterfall, the water acting m Fish and Waterman^s Compressed-Air Reservoir. eduction-tubes by whicli the air is discharged from the reservoir are of tiomparatively small diameter, and are provided with stop-valVes. Holly, May 22, 1806. Water is urged by the pis- ton C and forced Fig. 71. _ tlirough the curved piipe into the res- ervoir L. As the piston recedes, the valve in the liead of the air-cylinder T is ojiened, to supply the cylin- der with air. Wa- ter collecting in the reservoir is passed by a pipe to the cylinder T. Water between the piston and the air permits a water- tight instead of air- tight packing to be used, the air re- ti'eating before the column of water at each forward stroke of the piston and following it during its return stroke. Ransom, August 8, 1865. The two cylinders are connected at bottom by a hollow bed-plate A, and have a constant amount of water, which is made tlie intermediate between the piston in the cylinder B and the air which occupies cylinder C. As the piston descends, the column of water rises in cylin- der and ejects the air, which passes through the valve-way c into the dome 7>, the pressure closing the valve d. As the piston is raised, the water re- treats, the valve c closes, valve d opens and admits HoUy^s Air-Compressing Pump. m alternate compartments U, E, which are separated by a flexible dia]ihragm connected to an adjustiug-liar /), tliat operates the iulet and outlet water- valves e a, of each chamber. When either com- partment is emptied of the water contained therein. -^^ Wilhelm''s Air-Pump. an air-valve is opened and the air rushes in and fills the space vacated by the water, when, at the proper time, by the action of the floats F, and levers //', acting upon the diaphragm, the inlet-valve is opened, the water enters by virtue of its gravity, and the air is compressed and forced out of that compartment to a suitable reservoir, where it is re- served for use in any suitable engine. The etficieiit force depends upon the height of the column of waUM', and the consequent force with which the air was ejected by the water which dis- placed it. Jamkson, March 13, 1858. The air is compressed (or rarefied by the inversion of the jirocess) by the successive action of pistons in cylinders connected AIR-COMPEESSING MACHINE. 33 AIR-COMPRESSING MACHINE. me- '<■ Patric's Air-Coinprcssor. by pipes, who.se valves govern the direction of the flow. Each piston is eouneeted to a crank on the common rotary-shaft beneath. As the air passes from one to the other, it receives an additional con- densation, and is eventually stored in the reservoir n, at the end of tlie series ; from tlience it is drawn, as reijuired, to act as a motor, a blast, or for any other purpose for which it is adapted. The cylin- ders are enveloped by passages where a heater or re- Fig. 75. pressed to a certain tension. The amount of i'.'.erease in tension which the pumj) is recjnired to jnoduce need not exceed tliat at which it will work ailvanta- geously. In tlie last reservoir in the .series the air is further compressed by fo.-cing water into the low- er part thereof hy means of aiiotlier jiump. The air is compressed more and more by tlie suc- cessive opeiations, a single pump being required. The pump is connected to such one of the reservoirs as may be required, and discharges into another or others, tlie power required to work tlie pump being only the dift'erence between the pressure in the two. Dennison, October 23, 1866. The pistons are attached to cranks set at 180° on the same shaft, and reciprocate in cylinders of varying diameters, the larger having an air induction-pipe, and discharging into the smaller, which has an eduction-i)ipe. A water-jacket keeps the parts cool. By this means tlie air receives a double condensation ; tlie differ- ence between the sectional areas of the (lylinders is such that in each a similar amount of jiower is ex- erted. The imhictioii and eduction pipes of the single-acting cylinders Jameson^x Air- Compressor. frigerant may be placed to act upon the air. Air develops sensible heat as its volume is diminished by compression, and if it be used for cooling j)urposes, as in ice-making, its preliminary cooling before it is allowed to expand will make it more effective in ab- sorbing sensible heat when freed. Akthuu, July 25, 1865. An air-pump is com- bined with a series of air-vessels by means of pipes and stop-cocks, or valves, in such a manner that the air compressed into one air-vessel may be used to su])ply the pump when compressing air into one or more other air-vessels to a higher tension, the air entering the pump-barrel being thus already com- Fig. 76. Arthur^s Air-Compressor. 3 are provided with valves which govern the direc- tion of the air, opening and closing automati- cally. The pi]ie i; con- ducts water to the jack- ets around the cylinders, to remove the heat evolved by the compres- sion of the volume of the air. The pijie C re- moves the water. The abstraction of heat, of course, lessens the pres- sure. This is desirable for some purposes, not for others. Hot water or steam, acting in the reverse direction to a ^ refrigerant, would be adapted to increase the effect of the air as an expansive motor. Al- ternate expansion and contraction was the whole principle of the M. I. Bkunel Gas-Engine Patent, England, 1804. Fig. 77. Dennison^s Air- Compressor Ain-CONE. 34 AIK-DRILL. Ili'iitcil carljoiiU-'-ac-'id gas is jiiefei-able to air for ili'Vi'lDping a large loroe in small space. See Gas- KNlilNK. See also AiII-F.NOINE ; CoMFItESSEU-AlK Engine ; Am as a Wateii-elevatur. Air'-cone. In marine engines ; to receive the gases which enter the hot-well from the air-puni|i, whcne.', after ascemling, they escape througli a pifie at the to]i, — AuMiii.M. Smviii. Air'-cool'ing Ap pa-ra'tU3. In this article will be consiilereJ the devices for cooling a current of air, for purposes of health and ventilation, and not those involved in producing ansesthesia by cold, the manufacture of ice, or the cooling of fruit and njeat idiaiubers. These will be considered under tl\eir appropriate heads. The purpose of the former two of these is to reduce the temperature below the freezing-point, and of the latter to reduce it nearly to that point, v/hile for purposes of ventilation the aim is to reduce to a moderate degree the passing volume of air which escapes and gives place to that which is following. The ciieulation is not a necessary incident to ice- making or to the fruit-house, though in the latter there is no doubt that circulation of air is a valu- ble feature in retaining the purity of the atmos- phere in the chamber. Another large class of inventions in which an artiticial blast of cold air is employed is the beer and lii[uid coolers, which are of three kinds : thost; in which an artiticial blast is driven through the arms of the stirrer to cool the contents of the mash- tub ; tlio.se in which the liipiid is passed through a refrigerating vessel and is cooled by contact there- witli ; those in which refrigerating effects are im- parted to a vessel containing li(iuor on draft, to reduce its tendency to fermentation or to make it more palatable. See LiyuiD-cnoLER ; Ice-jianu- FACTUKING ; An.'Esthetic Appauatus ; Fill' IT and Meat Cha.mueu. The East Indian Tatta is a screen of finely woven bamboo in a frame which tits into a wiudow-o]ien- iug. It is kept constantly moist by trickling water, and thus cools the air as it enters the apart- ment, while the screen also excludes insects. The same elfect is produced by an arrangement which keeps moist the mosquito-bar around the bed. The Alcaraza is a Spanish form of the same device. SoMEs's plan for ventilating ships, February 2'^, 1865. The design of the aiiparatus is to expose a current of air to contact with vessels or pipes filled with water taken from a distance below the surface. The system of pipes is arranged at any convenient submerged point on the ship's sides, and the air is I forced in contact therewith by the motion of the the action of the waves. The cooled air is conducted by Fig- 78. jjipes to cool and ventilate the va- rious a])artments in the vessel, or the grain or other perishable freight with which it may be loaded. SeealsoTniERs's American Pat- ent, 1871. See Ship - ventilat- ing. In Somes's plan for ventilating, cooling, amb heat- ing the Capitol, the vessel. air is introduced into a vault so far beneath the surface as to be free from the changes of tempera- ture incident to the seasons. The air is conducted by a conduit, in which it is exposed to pi)ies whose contents have a warnung or refrigerating effect upon the passing air. rurifying and moistening in- fluences are also brought to liear upon the air. In his patent of October 15, 18li7, vacuum and compressing chambers are used in combimition with the pum|is which create the current of air. Atom- izing tubes are added to reduce the temjierature and impart moisture, the disseminated liipiid becoming vapoiized and absorbing free caloric from the air. .\nothi'r plan is to force a body of air through pipes which pass to the cold earth below the surface, or to expose air to the contact of pipes lilled with water which has been conducted to the said depth. It is suggested, in connection with this, that the air may be condensed in the cooler and become further cooled as it exjiands. Siialer's air-cooler. May 30, 1S65. The case contains a series of cells so arranged as to form a Fig 79. # r^ So7nes^s Sfiip- Vtntilator. Sltaler\'i Air-cooling Apparttlu,^ tortuov.s passage. The chambers are fillcil with ice, and the air is caused to circulate through the pas- sage by mi'ans of a fan. In Maine's apjaratus for cooling and disinfecting air, December 4, 1866, a continuous apron of |iorous material is passed through the tank containing the di.sinfccting and cooling liipiiil, and thence ] a.sses over rollers rotated by clock-work, its surl'ace being ex])osed to a current of air, generated by a fan whiidi is driven by the tame motor as the rollers. See Air-FII,TEn. Air'-cush'ion for Pipes. The object is to avoid the jar which occtirs v.hen a column of water in motion is suddenly ariested. Various incar.s have been tried, prominent among which are air-cham- bers. Air, however, is gradually absorbed by the Wiiter, and as a means of imprisoning it and still "al'owing it to contract when the jar comes, and afterwards to expand, it is enclosed in a ball of India - rub- ber. This is Fig 80. shown in Sevan's pat- ent, March ^ 14, 1865, and ;i in some oth- ers. The ar- rangemental- so allows the expansion of the water, in freezing, wi;liout bursting the pipe. The sack is placed in an eulaigement of the pipe, and so caged as not to stop the llow. A continuous tube of the same material, and containing air, is arraiiL'cd in the tube also. Air'-drain. (Buililin;/.) A cavity aronnMr.vs'.s air-driven carriage (Eng- lish patent, 1S2S), uher." air was con Imsed in tanks and admitted to the alternate en U of a cylinder, which had a reciprocating piston, connsctal in the usual manner to the crank and drive-s'iift. The same device, substantially, was used by Yon Rithen in 1S4S, at Putney, England, whore he ran an air- loconotive at the rate of ten or twelve miles an hour. See Ca.MPllBssED-.\in Exijine. 2. Those in which a boly of air is condensed into a reservoir, plac'd at tin bottom of a shaft, or in a situation where the prime motor ca;inot be set up. In this case the en;;ine in the min '■ is ran by the air from the reservoir during a lull in th.- force of the prime motor. This was the subject of a patent in Eng- land, t:) Mr.DHi'i'.ST, 1799. H;- condensed air to one fifteenth of its volume, and stored it for this purpo33. The air-re.servoirs of FisK (U. S. patent, 1885) have a similar purpose. See Aiii-coMPiucss- INT. M.iCIIIN-E. Another farm of air-engine has consisted of two ch.V!nh?rs filled with air or gas, and connectin,' b/ jiipes with the respective ends of a cylinder i i which a piston reciprocates as the bodies of air in the sai 1 cylinders are alternately e.'ipindenerator wherein the heat of the exhausting air is nndi to heat surfives which cuin- manicatc heat to the incoming air for the next charge. Tiie distinctive form of ajtparatus was no doubt new with Jtr. Stirling, but the nnin iilea is '■ muc'i o! ler, as it is found in the f2nglis)i patent of Giizibrook, 17-17. Stirling's regenerator is de- [ scribj 1 as "consisting of a chamber or chambers filled wih metallic sieves of wire-gauze, or minutely divided metallic passages, through which the air is ma le to pass oii'iorrd from the cylinder, after hav- ing performed its work on the working-piston of the en -line, leaving a great part of its heat in the sieves or uvno.v passages, to be given out by them again [ to the returning air, which is made to pass iuvmrd through the same sieves or naiTow pas.sages, and by i a sliglit accession of new heat from the furnace, to proiiuce another effective stroke of the piston. By ) re[ieating this process at each stroke of the engine, it is evident that a large portion of the lieatthat would otherwise go to waste will be useil many I times over, and thus a smaller amount of new heat will reiiuii-e to be supplied from the heating furnace of the engine, and a corresponding saving of fuel be effected." Such is the description, but the statement is onen to objections. A further improvement of Messrs. Stirling w;is patented in England, in ISiO. In this engine two strong air-tight vessels are con- nected with the opposite encls of a cylinder, in which a iiiston works in the usual manner. About four fifths of the interior sjiace in these vessels is occupied by two similar air-vessels, or ]ilunger.s, susjuMided to the opposite exti'eniities of a lieam, and eapal^le cf being alternately moved up and down to the extent of tiic remaining fifth. Ky the motion of these i.iterior vessels the air to 1 e opemted upon is 1 oved from one end of the exterior ve.-sel to ihe other ; and as one end is kept at a hi;.di temperature, and the other as cttld as possible, wdien the air is liTOUght to the hot end it becomes heated, and has i s pressure increased, whereas its heat and pressure are diminished when it is forced to the cold i nd. Now, as the interior vessels necessarily move in oi>posite diiTCtions, it f the e.xijeiKlituie cf 130.5 foot lbs. of merliaiiieal power. This is the real ilynainieal Slieiilie heat of air. The appiimit ilynainieal s|.e- eilii- heat of 1 11>. of air, under eons. ant ) le^suic', is, for 1° I*'ah., 183.7 foot lbs. ; the diti'erenei', or 53.2 foot lbs., being the nieehanieal i:o\ver exerted by the air in e.xi.aniling, so as to preserve the s:!ine pressure notwithstanding the increase of its teni- perature by 1'. The a]iparent sjiecific heat of air at constant pivssure e.\ceeds the real specific lh.it in the ratio of 1.41 : 1. All r[','antities of heat nuiy l!ius be expressed by eijuivaleiit ij umtities of me- chanical power. The heat recjuired to rai.se 1 lb. of water from the freezing to thc^ boiling ])oint, and to evaporate it at the latter temperature, is l,H7.r)'' X ' '2 = S8.i,870 foot lbs.: of which ISir X 77-J = 138,91)0 foot lbs. is sensible heat, or that ciiiploved in rai.siug the temperature of the wa- ter ; while "thi- reminder, 907. .j X ''''- = ''i'J.i'l" foot lbs., is the latent heat of evaporation of 1 lb. water at 2\2° Fah., or the heat that disajipears in overcon.iug the mutual attraction of the ]iai-tieles of water, and the external pressure under which it evaporates. The niechanieal equivalent of the avail- able heat produced by 1 lb. of ordinary steam coal may be taken on an average of that of the heat required to raise 7 lbs. of water fi'om 50° to '21::° Fah., and to evaporate it at the latter teniperaturi', that is to say, in round numbere, 6,000,000 foot lbs. The total lieat is much greater, but tlieie is a lass in the gases which ascend the chinine.-. "Heat, being conveitible with niechsiTii_al power, is convertible also with the ris nhy of a boily in motion. The British unit of heat, 1" Fah. in 1 lb. of water, is eijuivaliMit to the vis vivii. of a mass weighing 1 lb. moving with a velocity of 223 feet per second, liciiig the velocity accpiired in fall- ing through a height of 772 feet. A mass of water, of wldch each partic'.e is in motion with thi> ve- locity, has its temperature elevated by 1° of Fah. ujion the extinction of the motion, by the mutual frii'tioii of the iiarticlc's. Heat communicated to a substance ])roduces in general three kinds of effects (omitting the chemical and electrical phenomena): 1. An increase of temperature and expansive press- ure. 2. A change of volume, nearly always an in- crease. 3. A molecul.u' change, as from the solid to the licpiid, or from the lii|uid or solid to the gaseous state. The heat which ]iroduces the first kind of effects is known as sensible heat, and makes the body hotter. In the second and third kinds of ell'ects heat disappears and becomes latent. : but may lie irproduced by reversing the change which caused it to disappear. In evaporating 1 lb. of water at 212° a ipiantity of heat disappears equivalent to 711), 910 foot lbs. The i'res.sure of the steam ]iro- dueed is 2,116.4 lbs. on the square foot. The vol- ume is probably about 26;V cubic feet more than that of the liiiuid water. JIuItiplying these two quantities together, it appears that the heat ex- pended in overc(jming external pressure is equiva- lent to only r>B,08:'i foot lbs., leaWng 690,825 foot lbs. for the mechanical eipiivalent of the heat which disappears in overcoming the mutual attraction of the partiides of the water. Whereas the latent heat of expansion of a perm:inent gas consists almost entirely cf heat which ilisappears in overcoming the external pr--ssure. Thus the )iroduct of the volume in cubic feet of 1 lb, of air, .at ():J0° Fah,, by itsjiressure in llis. per square foot, is :j9,074 foot lbs. If that 1 lb. of air be I'xiianiled under pressure to 1 i times its origi- nal volume, and still be maintainedat the constant temperature of 650° by being su|q)!iid wiih heat ft'om an exteinal source, the work performed by it in exjianding will be 59,074 X hyperbou' logarithm of 1 ' = 23,!>.i3 foot lbs,, and this quantity will also I e .'■iMisibly equal to the mechanical equivalent to the hi'at supplied, and which disapiiears iluring the exjiansion. It is this heat which ilisa]qienrs in liroducing increase of volume under )>re.s.snie, which is the leal (oiirce of jiower in the peiformunce of a then: o-dyiianiic engine ; as it i.s a portion of this heat \ liii h is actually converted into mechanical work, V, Idle the heat expended in producing eleva- liuii of ti ni]ii'rature produces merely a ti-mh iiey to the developn.ent of power. When an elastic .svdi- stance has to perform niechanieal woi'k through the agency of her.t, it goes through a cycle of I'our pro- cesses, which, taken together, constitute a single stroke of the engine. " Prncess A. — The su1 stance is raised to an ele- vated tem]ierature. This ]irocess may or may not involve an alteiation of volume. " Process B. — The substance, being maintained at the elevated temperature, increases in vohiUie ai.d propels a piston. During this juocess heat disap- jiears, Ii'.t an equivalent quantity is su])]ilied from without, .so that the temperature does not fall. " I'meiss C. — The subst;iiicc is eouled down to its orig'nal low temperature, with or without a change of volume. " I niccss D. — The substance, being maintained at its di )iressed tem]ierature, is eompres.seil, by the return of ihe ]iiston, to its original volume. Iluring this ] rocess heat is jiroduced ; and in order that it n.ay not e'evate the temperaturi' of the suh^lanee, and give rise to an increased pressure, ini]ieding the iTtuni of Ihe piston, it must be abstracted as i|iiickly as produced, by some external means of lefrigeration. The substance, being now brought back to its original volume and temperature, is ready to undergo the cycle of jjrocesses again ; or it may be rejected, and a fresh portion of the sub- stance employed ibr the next stroke. In the latter case the operation of expelling the substance may take the jilace of process D. In some cases the pro- cesses B, C, or D may be first in the order of time. During the cycle of jirocesses the wotking substance alternately increa.ses and diminishes in volume in contact with a moving jiiston. During the increase of volume the pressure ^f the substance against the pi.ston exiiends mechanical power in compiessing the woiking substance. The increase of volunie takes place at a higher teu.jieratuie, and therefore at a higher pivssure .than the diminution of volume; consequently, the mechanical power communicated to the piston exceeds that taken away from it. The sur]ilus is the ]>o\ver of the engine, available for per- forming mechanical work. The cHicieiiey of the thermo-dynamic engine is the ratio which the available power bears to the mechanical e(iuivalent of the wiiole heat expended. If the heat com- municated to the woiking substance entirely dis- a]ipeared, the power jiroduced by that engine wou'd be the e.xact equivalent of the heat ex- pended, or 772 foot lbs for each unit of heat, and its cHicieney would be rejiresented by unity. A perfect engine would jiroduce jiower to the amount of 6,000,000 foot lbs., for each pound of coal con- sumed ; and as a hoi-se-power is 1,980,000 foot lbs. per hour, the consumption of coal would be 0.33 lb. per horse-])Ower ]ier hour. But of course there is a waste of beat and (lOwer to be allowed Ibr in every engine before we e;in arrive at its actual efficiency*." The elliciency of a theoretically jierfect engine, working between the same temperatures as Ei'icsson's, AIR-ENGINE. 39 AIR-ENGINE. would be 0.404, coiresfondiiig to a coiibUi:;[ition of 0.82 lb. of coal [icr borsL'-power per liuur. The ac- tual coiisuinptiuii was 1.S7 His. of aiithva- cito, or 2.3 Iij.s. of bitiiniinous coal. Tiiis is about .3.4 tiuifs tbe coiLsuiiiptioii of a tla-o- retically perfect en^^ine, and corresponds to an actual elHcieiicy of 0.118, being less than the maxiuiuni theoretical etticieiiey in the ratio 0.2y5 to 1. 'I'he wast* of heat and power, therefore, in Eiics-son's engine must have been very great, though it was economi- cal of fuel as compared with steam-engines. Many ot the nioilern forms of air-engines conduct the incoming charge of air tu the furnace and make it the means of mnintain- ingcombustion. The volatileresults, abound-.'' ing in carbon and deprived more or less perfectly of the o.\ygen, i-eijuire washing to remove the dust and soot which would oth- erwise pass to the cylinder. Combustion is thus maintained under pressure, a condition considered by many to be very favorable to the economical use of the fuel. Some of the air-engines of late construction use a larger or smaller ]iro]iortion of steam, partly as a motor and partly as a lubricator Fig. 81. [ su]>porting combustion in the furnace, the volatile I portions pass off by the pipe D to the wash-box E, Fig. 82. Waslibuni'a Air- Hfater and Steam- Generator. of the Bennett's Air-Heatrr anil Strani- Generator. parts which are apt to gi'intl, working in the hot, dry air. See Ai';iio-STE.\.\i Engine. Br.NNKTT, .\ugust 3, 1S3S. Thi.* is a combined air-heater and steam-generator, the eomliustion being maintained umler pressTU'c. The air is forced in by a jiump, and enters above and below the grates in quan- tities regulated by the dampers n, o, in the branches of the pipe B. Coal is introduceil through the charger C above, without allowing any notable amount of air to escape. Tlie upper valve c being withdrawn, a charge of coal is dropped on to the lower valve, when the upper valve is shut, ami the witlulrawal of the lower one allows the coal to fall into the furnace A. The volatile products of combustion pass through the water-tiap />, and mingle with the steam gener- ated in the jacket E. The caloric current is purged of its grit and soot by the water in the trap Z), and the combined heated air, gases, and steam pass by the pipe F' to the engine. An equal pressure is maintained iu the furnace and in the steam-geuerat- Ing chamber. Washburn, Septembers, 1865. The water pass- es by pipe G to the coil B, where it is converted into steam which [lasses off by pipe C -Air from a force- pump enters the ash-pit A by the pipe H, and after | tion heat does no enter where tlie gril a. id soot are arrested, i^ is a water- supply pipe and / a hand-hole for with- drawing accumulated matter ari'esti'd in the batli. After being deprived of iuj- purities, the air passes by the pipe A', and joins the steam, the two passing by pipe L to the engine. The pressure througli- out the apparatus is equal, the air and water being forced into it at a pressure equal to that of the outgoing steam and air. The steam-generating tube B, being exposed to equal pressure within and without, may be of light material, and the hot-air c:urrent may vaporize a por- tion of the water in the cleanser E, which is also supjilied under pressure. The strength is in the outer walls. Stillm.vn, Augu.st 9, 1864. The air- heating chamber is surrounded by a steam- generator, the steam from which is made the means, by injectors, of introducing the supply of air below the grate of tbe furnace, and also at a higher point, where it acts to assist the draft. For this pur- pose the steam in the generator is maintained at a higher temperature than the air in the furnace, and acts as a substitute for the air-pump in atloid- ing a supply of air for combustion of the fuel under pressure. After the foregoing treatise on the early history of the air-en- gine and the considera- tion of the princi]iles involved, the remain- der of this article will be devoted to examples of the air-engines which have been introduced dui-ing the last twenty years. They are about eighty in number, and may lie diviiled into live cla.sses, in all of which the air is ex- pamled by heat. (Air- ngines into whose ac StiUman\^ Hol-Air and Strain- Gt ni rntor. AIR-ENGINE. 40 AIR-ENGINE. as an effective agent are oonsidered under CoM- FKESSED-AIR Enoinu, which see.) 1st. Those in which the air is compressed into a res- ervoir, emitted in graduated amounts, lieated, Uocd ell'ectively aifainst a jiistou in a cylinder, and then discliarged. This is the most numerous oUiss. Some ot tliem pass their iiir-supidy tlirongh tlie furnace, and in otliei's it is only heated by the furnace. In thc! former the discharge of tlc^ air is a necessity, not so in the latti'i' ; this brings us to the '2d. Those in wliich the air or gas is not expended, but the same air is lauseil to return to tln^ heater and be again expanded and utilized. This is the subject of the Englisli patent of (JlazebruoU, 1801, an I Laubereau, 18.59 ; and tlie United States patent of the latter dated 184U. ad. Those engines in which the air or gas is not expi^niled, but occupies two reservoii-s communicat- ing with the cylinder on the respective sides of the piston ; the air in said reservoir being alternately heated and cooled to change its expansive force and thus reciprocate the piston. This was the form of Brunei's engine, British, 1804 ; and Stirling's, British, 1827 ; imd Peters's, 18«2. 4th. Those engines in which water or steam is min- gled with the air to moisten it and keep thc worl.- ing parts from abrasion ; in some ca.ses being intro- duced in quantity to be positively co-operative. These are Aiiiio-sTKAM ENriiNEs, which see. 5th. Tho.^e engines in which the power derived is transferred to a Ixxly of water, to prevent burning the working parts and to obviate the necessity for air-tight joints. It will be appai-ent that only a few I'cpresenta- tive e.xtunples can be shown within the limits assign- able to this subject, in which, as is commonly the case, some inventors have lunncrous patents embra- cing ilctails of construction, ius the working of their engines deveiopei.1 defects and elicited remedies. The lirst class is after the similitude of the Glaze- brook, 1797, and LiUey, 1811). Eiicsson patented improvements in air-engines in 1851, 185.5, 18,5(i, 1858, and 1860. Tlie following alt'ords iui ex.imple of one of his engines. Eiuc.ssuN, sp ^c ill jation patent of July 31, 1855, de- Fig. 84. iyics3on*s AtT-En^'nr (ISQj). scribes the invention substantially as follows (the illustration is reduced, from the official drawing, for this work ) : — b is the working-piston ; c, the supi)ly-pistoii ; /, the exhaust-port ; c, the induction-port. The re- generator consists of tubes k ; vi are the heater- tubes. By means of a hand air-pump, applied to some part of tin' regencr.ator, a supply of atmospher- ic air is introduceil at aliout the piessure of the at- mosphere, and then the engine is in a condition to begin its ojieration. Starting with the pistons of one engine in the position rejiresented in thc lov\'er view. Fig. 84, at the extremity of their outward stroke, as the crank s, moving in an ujnvard direction is making that part of its circuit near the outer dead-point, and therefore imparting but little mo- tion to the working-piston I), the supply-jiiston c is carried from the working-piston and towards the head of the cylinder with a lujiid motion by the action of the cam on the roller of the arm g, the cam rotat- ing in the direction aforesaid, and its acting face being formed as represented, that the piston may be gradually started, rapidly accelerated, and, near the end, gradually arrested, and there retained in a .state of rest as the extremity of the cam passes thc roller. During this inward motion of the supply- piston, the working-piston will be opened by the pressure of the atmosphere, to permit cold air to enter and till that part of the cylinder between the two pistons. So soon as the supply-]iiston stojis, the exhaust-])ort closes, and the continued inward motion of the \vorkiiig-]iiston begins to comjuess the cold air thus suiijilied, wliich of course closes the self-acting valve d, through which the supply was admitted by atmos]iheric pressure. Thus sup- p'.ii'd, cold air continues to be compressed by the «oi'kiiig-)iiston, until the end of its inward stroke ; and, as the (lower for effecting this compression is derived for the time being from the other engine, it is important to observe the condition (if the connec- tions. At the time the sniijily-piston of one engine is started, and the air is entering by atmosidieric pressure, and when the arm o, on rock -shaft ;>, with which the working-piston is connected hy the rod rt, is at its greatest leverage, the corresponding arm of the rock-shaft of the o]iposite engine is at its shorti'st lev- erage, but is moved inwards, and the sup- ply-air, by reason of being gradually com- pressed, increases the resistance, the arm o gradually shortens in lei'erage, and the same arm of the op- posite engine gradu- ally, and in nearly the same ratio, increases in levciiige, (m the jirineiple of the bent lever ; thus aji|ilyiiig the jiower reijuired to compi'css the sujiply. air to th(! best ad- vantage. It shouhl be borne in mind, however, that the powei- thus applied to coni|riess the sup- ply-air is not actually expended, but merely borrowed ; for it ia so AIR-ENGINE. 41 AIR-ENGINE. much acUled to the elastic force of the air by which, when heated, the engine is impelled. Just before the supply-piston begins the inward stroke, just described, the eduction-valve y is opened, the induction-valve h having beeii previ- ously closed so that the charge of the heated air, by which the previous stroke of the engine was effect- ed, is permitted to escape freely into the atmos- phere, so that the power recpiired to move the supi)ly-piston inward is very slight, the air escap- ing lively to the atmosphere on one side, and enter- ing by atmospheric pressure on the other, through the valve d ; but as the heated air exhausts or es- capes from the cylinder, it passes around and among the series of small tubes t, of the regenerator, thus imparting its heat through the metal of the tubes to the cold air contained inside of the tubes, which air is thus partially heated preparatory to being finally heated in passing through the heater-tubes. In tliis way much of the heat which wo\ild be otherwise wasted is saved. The supply of cold air liaving been introduced and compressed, the engine is prepared to be impelled by the expansive force of the heated air. The eduction-valve ;/, having been closed dur- ing the greater part of the inward motion of the working-piston, the induction-valve !i is now opened, which admits the heated air from the heat- er of the cylinder by which tire supply-pisto i U forced outwards towards the working-piston. The form of the fall of the cam I is such as to cause the piston to be carried back with a rapid acceler- ated motion, until it eomes nearly in contact with the working-piston ; and, at first, in this outward motion of the suiiply-piston, the already com- pressed supply-air between the two pistons is still further compresSLjd, not by the powei- of the engine, but by the elastic force of the heated air, the supply-piston being as it were suspended between the heated air from the heater on one .side and the cold air of the other, with the self-acting valve r (in the side of the cylinder) interposed be- tween the two ; for it must be ren\"inbered that, as the lleater and regenerator are in communication, the air, which is a perfectly elastic Huid, will be un- der equal pressure in both, notwithstanding a por- tion is more highly heateil than the other ; and, as the supply-air in the cylinder is .simply separated from the air in the regenerator by the interposed valve i; in the side of the cylinder, the s ipply-|)is- ton will be moved outwanls by the heated air, until the supply-air is compressed to an equal tension, and then the further motion of the supply-piston, effected by the cam /, as it approaches the working- piston, will transfer the supply-air from the cylin- d.T to the regenerator, through valve r. The "only power expended by the engine in this transfer will be the siiiall amount recpiired to move the supply- Jiiston, between two equal pressures, to give the slight preponderanc ; to the one necessary to open the valve ;-, through which the transfer is made. The moment the supply-piston passes this v.ilve and overtakes the working-jiiston, the preponderance of pressure ceases, and th" valve closes by gravity. Th; specification states : "I cto/m. the method of sui)plying fresh air to the engine, compressing and transferring it to the regenerator and heater, or either, by the action of the supply and working (li^tons within the one cylinder, operating on the principle ami in the manner substantially as de- scribed, whereby the air is admitted, under atmos- pheric pressure, as the supply-piston is moving from the working-pi-ston, as the previous charge of heated air is exhausting ; so that the said supply-piston moves in equilibrio, or lu^arly so, and by which also the supply-air is finally compressed and then transferred to the regenerator and heater, or either, as the supply-piston moves between the supply -air and heated air, duiing the periods of the nearly sta- tionary position of the working-piston. "1 also claim, in combination with the double- piston movement of each cylinder, the methods of connecting the working-pistons of two single-acting engines to constitute a double-acting engine, by means of two .sets of vibratory arms attached to each other, and vibrating on a common center connected with the two working-pistons, and with the two cranks on opposite sides of the crank-.shaft, the two sets of arms acting on the principle of the bent- lever, and the craiik-.sliaft being so located relatively to the cylinders and the centers of vibration of the arms, substantially as described, that the working- piston shall be at the end of its inward stroke at the time the crank is passing the dead point farthest from the jioint of connection of the connecting-rods with the \ibrating-arm, as described, by which the power of that working-piston which is being im- pelh'il by the heated air is applied to the best ad- vantage to operate the other working-])iston during its return-stroke, and by which also the workiug- (liston remains nearly at rest during the time the sup]ily-piston is making that part of its outward stroke, during which the partially compressed air is finally and fully comiuessed and transferred to the regenerator and heater, or either, as described." Since the exjieriments on a large scale, a smaller size of the Ericsson engine has been made efficient. An Englishman, who was deputed to examine the engine, made a pnl.ilished report in which the fol- lowing is found : — " They all gave complete satisfaction and appar- ently ample power for the purposes to which they were applied ; but without experiment it is impossi- ble to say what ciuantity of power they actually furnish respectively, liuf, judging by the aj^peaiance of things, they all worked well and with sui-])ris- ing regularity, evidently develoiiing a much larger amount of power from a given i[nantity of coal than could be obtained from steam-engines, as at present constructed, of corresponding ]iowers. And being sni'h that they may be placed in any location from which a chimney may be reached, and not requiring ^vatl•l■ or skilled attendance, they are particularly desirable as a driving jiower for small manufac- turers, who are thereby enabled to conduct their o] erations in the business parts of the cities, by oi-eupying upper lofts. " No attention is required for them while run- ning, beyond what is necessary to throw in a few coals occasionally, which is all that is required to keep up a constant and unilbrm motion, — which considerations become of impoitance to those who require a small power only. "As to the apjireciation of this machine by the public, it may w(dl be said that whereas it was a few years ago looked upon as a mere mechanical curi- osity, it is now regariled and acknowledged as a reliable motive power." The "London Engineer" adds : "That it is po.s- sible to construct an air-engine which will burn less coal than an average steam-engine has been almost jJi'oved, but it is wrong to argue from this that the steam-engine is 'used up.' Something more is wanted than economy of fuel. We need liermanence, absence of wear and tear, compactness, sinqilicity, and safety. In every one of these points, except perhaps the last, hot-air engines cannot bear a moment's comparison with the steam-engine. No large hot-air engines have ever been constructed and AIR-ENGINE. 42 AIR-ENGINE. worked with success. Tin- vubMng surfaces must bi; liuge, ami au cliicicht Uil)ri>;alioii Ijc-ouics an imiJos-siUlity, lu'iic: tVicliuii Is enormous. The di- mensions ot tlic working iiarts must be very great, or thi! temperatii.c ol' llie air very higli. .Surlaees nearly nd liut cut into each otlier, and tVii'tiou runs away with tlie power of the macliine, tile destruc- tion" of which is imminent each day. Considerable inij.rovements may be cll'ected in lubrii-ation, but e.^Ljierience with the steam-engine conclusively jiroves that the limit of temperature consi.stent wiiu practical working is very soon passed. It is not safe to use suiH'rheited steam much hotter tlian ■260 degrees, tlu^ east-iron of the cylinders and valve faces becoming disintegrated and sjioiled at higher temperatures. If air of no greater tempera- ture is used, we have an ell'eclive pressure of not more than 7 lbs., or thereabouts, per sipiare inch. Marine Fig. 86. StH'.maii'.i Air-Engine. engines with cylinders of IflD inches in diameter in'ist be replaced under such a eo idilion with oth-rs of M feet or 16 feet in diam.'ter. Then would com,' huge air-pumps and regeneratois. Tile machinery would take up as much space a< lioil- ers and steam-engines togeth- er ; and all this to save per- haps a quarter of a ]ioaiid of coal per horse per hour." Stili.m.vx, June 26, 1860. The air is compressed and worked in a single cylinder by a single piston. The air is compressed in the space below the piston B, passes by pipe E to the heater, and thence by valve F to the ef- fective space .-/ above (he pis- ton. As the piston rises, air is drawn in between the hol- low piston-rod 7/ and the plunger 0, cooling the for- mer, and is ejerteil again as the jiistnii descends. The in- duct ion -air enters at pi) lesfrf, as the piston li.ses, the an- n-Lilar valve It being raised by the friction of its stufiing-bo.x upon the hollow piston- rod 11'. The cylindrical chamber X is attached to the pi.^toii-rod i^, and rises and falls theivwitli .'-■o as to alternately draw and c;;;iei. air th.ou^h the annular space be- tween it and the cylinder, for the jdirpo.se of cooling the latter. KuFKii, June 0, 1^6--;. Tlie f.a-nace is lined with tire- brick on all sii'.es except the bottom. The air is con- densed in the pump above and jiasses ilown by the pipe Z, being admitted above or lielow the grate in quantities proi'orlioned to the requirements of the fuel. The air passes from the furnace ••/ by an opening d, and is a Iniitted, on the ri.-ing of valve 1, to tl.e .'ipace H, when it is ren- dered effective ■against the piston U. The e.xhaust- valve b is rai.sed to allow the de- scent of the piston, the valves being automatically worked by the usual means, and the cut-olf being adju.stable as required. B-\LD\viN, February 14, IbUo. In this engine the air is driven out of the force-]niin]i A by tlic descent of the piston B, which is connected by pit- man C with the crank D. The air from the pv.inp A passes, by passages //, to the tuyc'i'es / around the furnace J, into which it issues by a series of 0]ien- ings on the inner faces of the annular tuyeres. Tliese air-passage rings are interchangealile with the movable rings which form the lining of the furnace. The air pastes from the luimary to a sei-ondary furnace, and thence by [lassages and valve-ways to the working-cylinder il, wheie it Fig. 87. Roper's Air-En^ne. SalfJwin's Air-En^tiie. Ain-EXGIXE. 43 auti upoji thij piston F to raise the walking-beam I^, a.id tliL- latt.-r connects by pitman \iHii t;.e cr;ini< IJ. Tiie ilisk-valvcs are made of ilexiUe material, a: d ara guided by mar^nal, veiticai pins, wliieli Ibrm a cage to resti-.iin tli.- di>'.;s IVoni la.eral movement, ■ but pei!iut flee, \eitical p ay. 'J'lie air, after ex- [ paiidi:ig in tlie worUing-cyimder, beionies sendbly colder and is e;ihaasted i.ito tlie atinos]ihere. A ' eo:inejting-rod ecc^-ntri a.ly jojrnalej to the main- shaft operates toe.; wlileli trip the inlet and exhaust- valv.-.s (if the wurking-'-ylinder. Slcssint, M.ireh 7, 1S6j. The cylinder .-/, air- piini 11 /', and furnace C are on a plane, and the feed- bux l) over the hitler. The packed Jioition of the jiisto.i works in the upper part of the cylimler, ^.nieh is cooled by air in the pii-ssage /i, leading fioui the air-p.ii:ip to tlic farnace. A checn-valve in iliu passage prevents ihi- re.iux of air. The loumlaiion- jdiite of the engine has high .sides in, and forms a water-rcscrvjir in which steam is generated by ra- diation from the furnace-walh. A toi'-plateii lorms tlie top of the reservoir, and the cylinder is pro- tected by a doubL' wall which jirevents imnioder- a;e sniitraction of heat therefrom. Air fioiii the puniM circulate^ through the liollow grate-bars. A AIR-ENGINE. Fig. 89. in rojr's Atr-Engiiie. va've-ehest /. The raising of the 'T.lve ad::n's lo the elfective sp.ace below th" J i.ston, and i!^ by the tripping of tl:e adjustable cut-off arraji, jmrnp IS provided for injecdng combu.,tiblc tiuid, to I inent ; this is "effected late or early in the strol as may be required. J -" _. . . . Air-Eil^me. mix with the solid fuel in the furnace, and all th ; volatile products of combustion ai-e jiassed ti:ro'.lgh the working-cylinder, the iiEuuction and eduction Talves being worked in tlie usual manner. Wilcox, May Itf, 18(1=;. This engine is sub- stantially on the principle of tlie engine of Sir George Cayleys (about l^KO). The fire is fed with air, under pressure of a puniji, and the volatile ]n'o- ducts of combustion are passed tlirough the work- ing-<'ylinder AVith each desci-iit of the piston air is drawn through the inhaling valve F, and tills the space above the piston, tin the ascent uf the valve the ail' is driven through the regenerator, and becomes jiartiaily heated by contact with the ducts carrying out heated exhaust-air. It thence passes by pipe H to the furnace, a part entering above and a part below the gi-ate as regulated by the faucet-valve. This valve is worked automatically by a ihermostatio arrangement, so that when the tire bei'omes unduly hea*''d the supply driven throuyh tlie fuel is de- checked. The compressed cre.asdand combu.stion checked. Tlie comjuei and heated air theiice passes, by pipe B, to the | communicates motion to the crank -shaft, and toward The doors of the furnace and a!>h-]iit arR secured by cramps and hollow bolts to the walls, and are removable to replenish the fuel, or for grinding or packing lo make an air-tight joint. 2. The second class is as the principle of the English patents of Glazebrook, 1797 ; and Parkinson and Ci'osley, 1827. L.\rBEitK.\u, April 10, 1S49 ; patented in England, 1&47. This engine is the first which emlmdies the jieculiar features of a furnace in the air-heating chamber, and a hollow plunger of corresponding form. The air is alternately dilated and contracted by alisorbing and giving out caloric, the air when separated by heat forcing up a piston in a cylinder, which is in turn forced down by the jiressure of the atmosphere when the air is condensed by the ab.stiaction of heat, th" .lir tor the alternate dilatation and con- traction being carried over a heating and cooling surface by the motion of a iilunger in a cyliniler that comnnmicates with the cylin- der of the enaine. The plunger is made hollow, with its ex"er7ial and internal surfaces made of some good comliu'tor of caloric separated by a non-concluctor, the said jilunger being adapted to move witliin a surroniuling cooling- vessel and to coniliined with a heatiiig-\"cssel made of some good conductor of caloric, and heated bj' the application of lieat inter- nally, that the said hollow ]ilunger shall alternately cover and uncover it, and thus cause the contained air altei-nately to pass over the heated surfaces to dilate it, and then over the cold surfaces to con- tract it, the said surrounding vessel being in con- nection with a cylinder to which is adajited a workimr-piston. The operation is as follows : before heat is applied, air is admitted, under the liressure of the atmosphere, through one of the valves or cocks ; fire is then made in the furnace until the contained air is dilated; a portion of which is then permitted to escape through one of the valves or cocks, which is then closed. The heat is then continued until the air has aequiied sufficient elasticity to force up the piston. This AIR-ENGINE. 44 AIR-KNGIXE. the end of the upnanl motion of tlie piston, tlie cam on the nuiin shiift iiiovis tlie plunger until it covers the heatiT, and this motion of the plunLjer "~ fie 00. Laitberemt's Air-Engine (1847). causes the air contained between it to pass be- tween its outer surlace and the inner surface of the surrounding vessel, and to aceumulate at the back end of the plunger, so that, the heat being en- tirely shut in, tlie .air is cooled by contact with the cold surface of tin- surrounding ease ami outer surface of the plunger, the air thus contracted pro- ducing a partial vacuum which peiinits the piston to he forced down by the pressure of the atmosphere above. As the piston approaches the end of its downward stroke, the cam moves back the plunger, which transfers the cold air from the outside to the inside, thus causing it to pass in a thin film over the surfai'e of the heater and the inner and heated surface of the plunger. It is thus iigain dilated, that by its elasticity it may again force up the piston. Fig. 91. Laub'Ttau's Air-Engine (1859). Ill this way eaili stroke of the plunger causes the air to pass over the heated surlaces to dilute it, and then over the cold surfaces to condense it. The plunger also has the elleet to shut in the heat of the heater, receiving lieat therefrom in the mean time while its external surface is kept iidd by the surrounding ease, the non-conductor interposed between them ]>reventiiigtlie heat of the ii.tci lu.l surface iVom beirg transmitted to the external suiface. This engine has been since modilied (patent in Enjilaiid, July 22, l^.V.i) by the introduction of a valve in the pas- sage between tlie heater and work- ing-cylinder, and at the eduction from thence into tlie pipes which conduct the air lack fiom the working- cylin- der to the cool end nt I he chamber. This air-engine is said to be coming into great favor on the continent of Eu- rope, and in the later form is very eompact. The operation of the engine is so similar to the preceding that it does not call for a lengthy description. The jacket around the cool end of tlic air-chamber lias a current of water, or some other means of lefrigeration, so as to lender it nioi !■ proni]it and c fl'ectivc in its action cm the air. The wovhing-eylinder is connected altciiiately to the respective ends of the chamber below, by p;is- sages whose ■(•alvcs ojieii and close, according to the direction of the current. ScHWAUTZ, December 20, 1S(34. This invention is thus described officially : " The object of this invention is to produce an air-engine to work u]ion the recu]ierative system, and thus to use the same air OA'er and over. Its novelty consists, first, in the generator, which is composed of a strong flat- sided vesscd, with rounded neck at the to]i, which is suspended over the tire in the funiace. From the bottom of this generator jirotrude downwards several bottlc'-shaped tubes which arc ojicn to- vu'ds the inside space of the generator. Tills geiic-ratcir is filled with a licpiid wliose boiling-point is very high, say ficiiu .'■jOO° to 7(10". The air heated in the generator passes through a ]iipe to the cylinder, wliicdi constitutes the sec- ond novel t'eature of the engine, and is composed of three distinct iiarts, the central one of which is the working- cylinder, the end ones being filled with __ — ^ small tubes, into which rods are fastened 2^^^ to the piston-neck for the pni'liose of ** ■ agitating the entire body of air during the process of expansion. The third AIR-EXGINE. 45 AIR-ENGIXE. feature of novelty consists in passing tlie gas, after it lias expended its force upon the piston, through the generator, which is constructed rectangularly, and has a dividing ]ilate in its center. This vessel is tilled n-ith horizunt;d tulies, which are closed at both ends, and are j^artialiy tilled with a fluid which is designed to extract the heat from the air cr gas as it passes from the engine, and transmits it to the air which is passing to the opposite side of the piston." 3. The third class is on the princijile of the Stir- ling engine, descril>ed in a preceding portion of this article. Peteus, November 18, 1862. The air is lieated Feuns Air £.,., in two vessels connecteil with two opposite ends of the working-cylinder, and the invention consists in so operating the two plungei-s that the one in cither heating-vessel is stationary in its uppemiost ])osi- tion, with the sjiace below it fuU of heated air, while the working- piston is making the stroke from the end of the cylind>r in con- nection with that vessel, the plun- ger in the other heating vessel m.ik- ing both its upwani and downward stroke in the mean time, and cius- ing th>' latter vesscd to lie filled with heated air to pro l-ice the return stroke of the working-pis- ton. Tlie gland which is used to compress the packing in the stuf- ^ fing-box is made witli a deep cup " in its upper part for the reception of oil. and around the upper edge of this cup is secured a leather collar in close contact with the plunger-rod, so as to prevent the escape of air. Fig. 93. See Bickforartment. Air '-foun tain. A contrivance for producing n jet ef water l.iy means of compressed air. Air'-fuaue!. A cai ity Ibr.ned by the r mission of a timber i.i the uppe. works of a vessel, :o lo.- -. Herron's P itpil- Ventilator. a duct for the admissioQ of pure air and i.ie escape of foul. Air -far nac8. A term used to signify a furnace !i ivi I a n It uil d.Lii't, no blast. Air'-gratiuj;. \n iron grating in a wall, to allo.v veii:i.at;iuu. Air'-gun. The air-gun is a pneumatic engine for tiring bullets or otluT projectiles liy force of compiessed air. The child's popgun illustrates the principle of the air-giiu : a iiellet is forced through a tube or ipiill bv a ranuner from the laigcr to the snnller end, where it sticks fast, and another pidlet i.i jnit in and pressed forward in the same manner, conil. using the air between them, when the jiressure on the lirst pellet overcomes its Irictional ailherence to the sides of the tube, the pellet is releiued, and IS piojected by the force of the ex]iar.ding air. The MUcicnts were ari|uainted with some kind of an ajijiaratus by which air was made to act upon the sliortei- ai-m of a lever, while the longer arm imiielled a piojcctile ; and it is said that I'ti'-siphus of Alex- andria, a celebrated mathematical philoso]iher, who lived l>. C. 120, constructed an instnnm-nt in which the air, by its elastic force, discharged an arrow from a tube. (Montucla, " Histoire dcs Mathematiques," Vol. 1. p. 267.) The first ac- count of an air-gun is found in Da^^ll Rivault's " Elemens d'Artillerie." He was jireceptor to Louis XIII. of France, and ascribes the invention to a certain JIarin of Lisieux, who presented one to HeniT IV. of France, about A. 1). 1600. An instrument of this kind was invented by Guter of Nuremberg al out A. D. 1656. Various .shapes have been adopted, from that cf the ordinary nuis- ket to a gun lesenil ling a couiinon, stout walking- stick. It consists ot a lock, stock, bantl, and lam- rod ; and is jm -■viiled with proper cocks h.r filing it with comjin-.-sed air ly means of a foicc-jamp. Th» lock is only a valve which lets into the 1 arvel a portion of the ;,ir com] ressed in a ch::nil er in the stock when the trigger is pulled. The gun is load d with wadding and Kill in the oidinary way, ai.il when fired there is but little ncise, and none of the oth.er concomitants of /T.npov der, sn'.oke and : odor. The v.s-..al range to which the air-gun ] loj els a bnllit is Item si.xty to eighty yards. In tl.ose , guns having a sliding trigger, two or three bv.llets ' arcsuccessivelyand separately intniduced, and may be I exp'dled by one mass of condensed air. Air-guns have also 1 een constnuted upon the j rinciple of levolv- ing pistols, ailmitting the expulsion of several 1 ullets after once charging with comjiressed air. i^cme varieties have an air-pump attached by means of which a mole jowerl'ul compression of air may be produced. One air-gi;n in the I'onn of a cane Las two baiTcls, — one small one fir the recejition of bullets, anil one large lore for the re.sen'oir of ( onipressed air. ?;iastie springs have also been used in conneition with ciim]ires;ed air, but the latest imiirovi meuts arc those of Cornelius Bori.i± ^": fiaii Plate II. PIER AND CAISSON. ILLINOIS AND ST. LOUIS BRIDGE. .See page 49. AIR-HEATER. 49 AIROMETER. He was probably tbe tutor of Hero and tin- LOiilem- porary of Archimedes. Otto Guerieke reinvented and applied the air-pump ; Boy.c made it a \aluable instrument. Air'-heaf er. A stove or furnace so arranged as to heat a current of passinj; air, for warmih or ven- tilating purposes, bee HEAriNti Fl'ilnace ; Heat- ing Stuve ; Heating Ai'i'A.,Arfs, etc. Fig. 106. Air-Holder. Air'-hold'er. A vessel generally of a cylindrical form, with its open end plunged in a tank of water, and intended to contain air or gas. Its use is com- mon in a varieU' of machines and apparatus where a steady and nioiftrate current of air is required, as in machines lor carbureting air and gas, aspirators, etc. Also in michinery on a larger scak", such as blowers, ventilating-machines, etc. The air is introduced by a bent pipe turned up- ward inside the tank and hoMi'r, and is educed in a similar manner. On a small scale the vessel may be charged with air by raising the upper valve and lifting the holder, and the air may be with- drawn by a fli'.';ible pipe attached to the holder. See AsPIRAnill ; C'ARBUi'.ETING AlR; Bl.OWEl!, etc. Air'-hole. {Foimdhuj.) A hole or cavity in a casting pruduc^d by bubbles of air in the liijuid metal. A vent-hole in a mold for casting. {Furi)(ic\) A draft-hole in a furnace. It is some- times guarded liy a register ; sometimes stopped by a luting (ir plug of clay. Air'ing-stage. A platform on which powder, etc., is dried I>y exposure to sun and air. Air'-jack'et. An air-tight swinuning-jacket ca- pable of intlation. A garment with indatable lining or pockets to serve as a life-preserver. Air'-lev'el. {Siirvci/ing.) A goedetic instrument invented by M. Thevenot. The level is determined by means of an air-fnibble in a glass tube nearly filled with colored spirit. Generally termed a spirit- level ; though the air-bubble is the dominant feature. See Level. Air'-lock. (Hijd. Eng.) A pneumatic contrivance in a hollow caisson whose lower chamber is filled with compressed air to exclude the water. A trunk con- nects the submerged chamber with the external air, and has two valves. The descending workman en- ters a chamber in the tube at the atmospheric press- ure ; the upper valve is clos"d, and his a]xirtment is charged with air from the lower chamber ; the lower valve is then 0])ened to admit him to the working-chamber. The cut on the page opposite is a sectional view of the East Pier and Caisson of the Illinois and St. Louis Bridge, in course of construction by Captain James B. Eads, across the Mississippi. The view shows the interior of the main entiance-shaft and air-chamber, and the working of one of the pumps. The caisson is represented as having descended through 60 feet of sand, silt, and gravel which form the sand-bed of the river ; 20 feet of excavation re- maining belbre the bed-rock is reached. The pier of masonry is built on a strong bulk- head of timber and iron, supported on a curb which rests on the sand-bed, and is strengthened and sus- tained by timber girders which divide the working space beneath into several chaniliers which comnni- nicate through holes in the partitions. The pier is enclo.sed by an iron envelojie II, which is watei-tight, and prevents access of water to the pier and the workmen. Until the curb of the caisson reached the sand-bed it was sustained in erect position by screws from the trusses of the guide-piles, but was afterwards preserved erect by digging away the sand eijually at all the points upon which it rested. / / are timber luaces which support the shell H. K K are pontons alongside, which support the steam-engine, air-pumji, ndxing and hoisting ma- chinery, and the oliices and quarters lor the stair and hands. .S' is the steam-engine which drives the air-pump R, and the air is conducted by the hose U down to the chambers B B, where the excavating is proceeding. The sand is loosened by water and the pick, and is driven liy condensed air up through the sand-]ium)is E E, which discharge at D. The air-locks^/ A are chambers intervening be- tween the main entrance-shaft F, where the air is at the natural jiressmv, and the chamlx-rs B B, w here it is in a much condensed comlition. The visitor steps from the shaft F into the air-lock A, the door of in- gress is clo.sed, and coi.den.sed air is then admitted. When an eiiuilibrium is established between the chaniliers A and B, the door between is ojiened, and the visitor finds himself on the scene of action. As the caisson de.scciiilv, ^uccessive courses of stone are laid on the ] iers by means of traveling-purchases 0, which move on the Wire ropes M M by means of hoist- ing-ropes X N. G G are side shafts ; /J cabins for operatorsof purchases ; LL hydraulic jacks forlifting materials ; V pipe for water to sand-piinip ; V V trusses for guiile-piles ; Z inixiiig-room ; A' office. See Caisshn. Air'-ma-chine'. A machine forventilatingmines. Air'-met'er. An apparatus for measuring the quantity of air passing along a pipe, or passing into or from a chamber. There are various forms : the fan, rotating spiral vane, expanding bag, cylinder and piston, revolv- ing partially submerged meter-wheel, etc. As their principal adaptation is to measuring gas, to avoid unnecessary repetition they are assembled under Gas-meteh, which see. Air'o-hy'dro-gen Blow'pipe. An apparatus invented by Dr. Hare, in wliicli the Lssuing air is assisted by "a jet of hydrogen to intensify the llaine. See Blowpipe. It is especially used in autogenous soldering. Air-om'e-ter. The term is applied to a hollow cylinder, closed above and open below, with its lower edge plunged in a tank, and used to con- tain air. The tenn has been derived from its sim- ilarity in shape to a gasometer, the change in the lirst sj'llable indicating the different contents. Its use as a meter is unfiequent, and it is prop- AIR-riPE. 50 AIR-PUMP. LTiy called an air-holder among experts. See AlR- HOLDF.U. Air'-pipe. {Slenm-cnginc.) 1. A small copper pipe k-ailini; tVmii the top of the hot-well througli the ship's side, for the discharge of the air and uncoiidensed vapor removed by the air-pump from the condenser. 2. A pipe used to withdraw foul air from or force pure air into close places. Air'-poise. An instrument to measure the weight of ai r. Air'-port. An opening in a ship's side for air ; closalde by a shutter, side-light, or dead-light, ac- I'orilins to circumstances. Air'-press'-ure Pil'ter. A filter in which the percolation of tlie liipiid is assisted by atmosiiheric pressure, induced by a partial vacuum in the lower chamber. Spencer's air-pressure filter, June 4, 1867, is particularly ad.ipted for the use of pharmaceutists. C is the air-pump, secured by a clamp to the edge Fig, 107. Spencer's Filter. of the table. Tlic filter A rests on a packing on the lip of the bottle B. The air is withdrawn from tills latter to increase the rate of filtering. Claim. — First, in an atmospheric filter composed of the tunnel A, bottle or jar B, and air-pump C, the employment of a packing h for the purpose of producing an air-tight joint between the tunnel and Fig 108. Crruber's Filler bottle, the whole combined and operating as hereic set forth. Sei'ond, the arrangement of the filtering medium d d with the removable perforated diaphragm/, when operating in connection with the shoulders c c, as herein set forth. I) is the air-eduction pipe. The vessel A stands in the collar-piece/, the latter on the bottle, whose lip has a packing-gasket. In Ghuuer's air-jiressure filter, April 3, 1866, the filtration is assisted by an air-forcing and air- exhausting pump, connecting by pipes with the two chambers separated by the filtering substance, j and k are the openings of the plenum and vacuum pipes into the chambers E and F. The lid is fas- teneil on, and has an air-tight packing. The pump G draws air from chamber F, and impels it into chanilHT E. For Water - pressure Filter see riil'.ssl-p.K-FlLTER. Air'-pump. Invented by Ctesibus of Alexaii- dria, or previous to his time. Hero, of the same city, the author of the " Spiritalia," shows it in connection with several of his pneumatic contriv- ances. He also shows a fire-engine with a ]iair of single-ai'ting pistons attached to a walking-beam and operating alternately in their respective cyliudei's. February 15, 1665, Mr. Samuel Pepys, the gos- siping author of the famous Diary, was admitted a member of the Koyal Society, the meetings of which were held at Gresham College. He says : — " It is a most acceptable thing to hear their dis- course, and see their experiments ; which were this day on fire, and how it goes out in a place where the ayre is not free, and sooner out when the ayre is exhausted, whii-li they showed by an engine on pur- pose Atiove all Mr. Boyle was at the meet- ing, and above him Mr. Hooke, who is the most, and promises the least, of any mam in the world that 1 ever saw." The air-]nin',p was reinvented by Guericke of Magdeburg, about A. D. 1650. Since then this instrument has been much improved by Hooke, Papin, Hawksbee, and Boyle. Many varieties of structure have been de- vised, the priueiijle of all being the same. The basis or essential part in the air-pump is a metallic or glass tube answering to the barrel of a conmion pump or syringe, having a valve at the bottom opening upwards: ' and a movable piston or embolus, answering to the .sucker of a prmip, the piston or cylinder being furnished likewise with a valve opening outward. The pump must be closely fitted by a i metallic connecting-tube open- 1 ing into or under the vessel which is to be exhausted, which is usually formed by placing a bell-glass, called the receiver, with the edges ground smooth, and smeared with lard or wax, on a lat, smooth plate or table. When the jiiston is at the bottom of the barrel, and is then drawn up, it lifts out the air from the barrel ; and a portion of the air from the receiver by its own expansive force passes through the connecting-tube, and occupies the jilace below the piston which would other- wise be a vacuum. The air in the receiver and barrel is thus rarefied ; the jiiston is now forced down, closing the valve jilaced at the mouth of the connecting-tube, and causing Otto von Fig. 109. AIR-PUMP. 51 AIR-PUMP. the air in the barrel to escajie througl the valve in the piston. This op ration is again anil again re- peated until the receiver is so nearly exliausteil that the elastic force of the remaining air is no longer sufficient to open the valves. The fonu of the pump may consist of two hansels (each having a piston) having a junction mtli each other at the point where the connecting-tulie is attached, and ofierated alter- nately by a lever attached to each piston and sujv ported at a point midway lietween them, or by means of teeth or cogs cut in the piston-rod, and operated 1>y a cog-wheel, as shown in the accompanying figure. The valves may be made of bladder, oiled silk, or gntta-pereha, the Ijest form of which is a .small hollow cone \vith a slight cut at the top ; stop-cocks must be attached so as to control the admission of air. The pressure of the atmosphere being about fifteen pounds to eveiy sijuare inch of surface, care must be taken that the receiver and banels of the pmup Fig. no. Bawksbee''s Air-Pump. be so constructed as to bear this weight without accident. A gage to ascertain the point of rare- faction can be made by introducing the lower end of a graduated glass tube, connecting with the iv- ceiver, into a cup containing mercury ; as the air in th e receiver is exhausted, the pressure of the atmosphere on the surface of the mercury will force it up into the graduated tube, so that its rise and fall will indicate the rarefaction. A per- Fig. 111. feet vacuum can never be made, for it is evident that the exhaus- tion caTi never be complete ; even \}i theoretically, there must always be a portion of air left, though that portion may be less than any f'lf'j) ^'" ' '" ' r^ ^ assignable quantity. Many use- ful and interesting experiments can be performed mth the air- pump, illustrating the effects of atnin-p'ieric pressure and other mechanical properties of gases. In Sie.men'.s air-pump the two cylinders or barrels diH'er in size and arrangement. The smaller barrel is applied either to the bottom or toji of the larger, while the valved pistons belonging to each are attached to one and the same piston-rod. The air with- drawn from the receiver is con- Sicmen^s Air-Pump densed in the lower cylinder to one fourth of its original volume, and thus has suffi- cient elasticity to pass through the dischai-ging val ve and es<-a]ie, the opjjosing pressure of the atmosphere on that valve being thus counteracted from within. In the illu.stration, A is the exhausting-cylinder, B the second cylinder, equal in length to the first, and fixed to its lower [art, but having only one third or one fourth of its sectional area, and conse- quently one third or one foiuth of its cubical con- tents. The cylindei's are separated by a plate fonning at once the bottom of the upper and top of the lower cylinder, the only passage between them being a silk valve if. In eacli cylinder works a valved )iiston, F and ;), attached to a piston-rod common to Uilli, and passing through a stufling-liox in the jilate. The distance l>etween the pistons is such, that ^\l;cn P is in contact with the top of the upper or exhaust- ing cylinder A, p is in contact with the top of the smaller or lower cylinder ; and when P is in contact with the lx)ttoni of the large cylinder, p is in con- tact w ith that of the small cylinder. The table or pump-plate E, placed above the large cylinder A, supiKirts the receiver Fi, or other vessel to be ex- hausted, from which the air flows through tl;e valve r, during t'.ie descent of the piston. The motion of the pistons is eiTected by means of a short crank with a jointed connecling-i'od, converting the circular motion given by the lever-handle into a vertical one, which is maintained by means of a cross-head, with rollei's working between guides. The action of the ]ium]i is as follows : The de- scent of the piston P tends to produce a vacuum in the exhausting-cylinder A, by causing a difl'erence of pressure above and below the fii-st valve c, in the top of A, so that the ela.sticity of the air in the receiver causes it to pass through the va've v. At the same time the air below P is pressed l!iro\igh the valve v', in the plate which sejiarates the cylin- ders, and enters B, in which a vacancy is sinud- taneously made for it liy the descent of the piston ;) ; and in consequence of the difference of cai>acity of the two cylinders it becomes reduced to one fourth of its original bulk, its elasticity being p;o- portionally increased. The air contained in the small cylinder below the piston ;) will in like man- ner be pressed through the valves v" v"' into the external atmosphere. During the ascent of the pistons the vahes r r' will be closed and ic iif oiiened b}- the downward pressure of the air in the cj'linders, and v" v'" will be closed by the atmos- phere, thus allowing the air in each cylinder to pass through the pistons as they rise, in order that in the follo%ving downward movement the air, which during the previous stroke of the pump issued from the receiver into the exhausting-cylinder, may be withdrawn from that into the lower cylinder, while the air condensed in the latter may be finally ex- pelled into the atmosphere. See AlR-C03irREssiNG Machine. The air-pump of Boyle was inconvenient, as it demanded alternate opening and shutting of the stop-cock and vdve, and difficulty was also experi- enced in making the piston descend when the air within the pump was greatly rarefied. H.^^vKSBEE's air-pump, previously cited, had the dujilicate cylinders, with pistons which were moved by means of a crank and jiiuion. The piston-rods were toothed racks, which were engaged by the pinion, to which a reciprocating rotary motion was imparted. The 1 ottom of each cylinder comnumi- cated by a pipe with the receiver on the platfonn. Sme.a.ton's air-pump was an improvement on Hawksbee's in two respects. Hawksbee had found considerable difficulty in opening the valves and ex- AlE-PUMP. 52 AIE-PUMP. Fig- 112. hausting tlie air at the bot- tom of the liar- rels, owing to the fact that thejjistonsdid not shut down close on to the bottom. The first defect arose from the snialhicss of the orifice in the bottom of the cylin- der through which the air entered ; the bladder being kept moist with oil ad- hered to the metal and re- sisted the up- ward pressure at so small an opening. This defect Smea- ton cured by exposing a greater sur- face of bladder to the u})ward action of the air. He used a congeries of holes consist- ing of six hex- agonal open- ings surround- ing a central one. The parti- tions between these holes were filed near- ly to an edge, and the whole formed a grat- ing on which Snifaion') Air-Pump. the bladder- Talve lay, of- fering lint .slight cohesive opposition to the raising of the valve as the piston ascended and the air from the receiver pressed upward against it. Fig 11.3. Rotary Air Pump. To prevent lodgment of the air in the lower part of the barrel, he removed the external pressure from the j)iston-valve, by making the piston move through a collar of leather, and forced the air out by a valve applied to the plate at the top of the bar- rel, which opened outwardly. Cuthbertson of Amsterdam introduced the im- provement of mechanically opening an escape for the air without depending upon its elastic force to open the valve leading to the cylinders. Air force-pumps are used for the supply of air- carbureting machines. A conunon form of these consists of what is called a meter-wheel, from its resemblance to the measuring-wheel of a gas-meter. Fig. 113. In the illustration the buckets M are curved, and gather in the air of the chamber A. As the wheel rotates the air is discharged, near the axis, into chamber 0, and is conducted by a pipe to the hollow trunnion through which it is discharged. Another i'orin of air-pump used in carbureting- machines is on the jwinciple of the gravitating air- holder, which consists of a weighted inverted cylin- der whose lower edge is submerged in a tank. See Air-holder. A conversely acting device on a larger scale is used for pumping air from mines. In the Annalcs dcs Fonts ct Chaiissies, an air-pump Fig. 114. Ventilating Air-Piiwp is described, used to ventilate a shaft 5 feet in diameter and 220 feet deep. The work had been several times suspended, owing to the accumulation of carbonic acid gas, and the ordinary bellows had been found inefi'ectual. A large tub (Fig. 114) was firmly placed on balks on a level with the top of the shaft, and filled with water nearly to the brim. An air-tight jiipe from the bottom of the shaft was brought through the tub, and had its upper edge a very few inches above the water ; it had a valve on the top. A smaller tub, reversed, was suspended ■within the lower tub by cords, which were made fast to the ends of the levers. The upper tub had a very short pipe at top, with a valve opening upward. The upper tub lieing allowed to descend Tiy its own weight, the air within it was exjielled through the upper %'alve ; when again raised, by pulling the AIR-REGULATOR. 53 AIR-THERMOMETER. handles attached to the ropes, the air was drawn up through the valve-way at the upper end of the de- scending tube, and by continuing this reciprocating action, a circulation was created at the ver)- bottom of the shaft. Bunseu's air-pump is a means of withdrawing air by entaugling and carrying it with a falling body of water. It is sjiccifically known as an asjirator in its uses to obtain atmospheric pressure in filtering, in removing etfete or poisonous air fioni apartments or the vicinity of gangienous wounds. See Aspira- tor. Tlie same principle is involved in the " water- pumps," so culled, which withdraw the air and steam from the evapomting and vacuum pans of sugar-re- finerie.s the injection-chamber of the condensing steam-engine, etc. Air-pumps are also constructed, to act on the principle of the Giffard Injector, the' active column being a body of water or steam. See Steam-jet ; Ejector. Apparatus for compressing air as a motor, as a water-elevator, etc., are considered under several heads. See Air as a Water-elevator ; AiR- cojm>res,sing JI.\chixe ; Air as a Means of tpa.nsmitting Power ; Air-engixe, etc. 2. {SIcnm-; Fig 115. engine.) A' pum]i used in condensing St earn - e n- gines to re- move the air and uncon- densed steam from the con- denser in or- der to perfect the vacuum therein, and in tlie cylin- der to which it is period- ically con- Air-Pump. nected. £ is the in- jection-chamber, which is submei'ged in the cistern C. The uncondensed gases and water escape by the valve-way G, called the foot-valve, and ascend through the valve of the pump-1 ucket p as the lat- ter descends. The next ascent of the bucket drives them out at the vave-way Q into the hot-well. Air-reg'u-la'tor. A "contrivance for detennin- ing the (piantity of air admitted in a given time. Registei-s and danijiers are the usual devices ; the former has usually a sliding and the other an oscil- lating motion. Furnaces, stoves, ovens, etc., are usually furnished with some means for regulating the supply of air ; when the heat of the stove is made to regulate the register the device is called a Thermostat (which see). I Air-i-egulatoi-s may be made to act on the principle of the gas-regulator, thedegreeof pressuredetermining the area of the oiiening, so that a given quantity may pass in a given time ii'respective of the pressure. Air -scuttle. {Ship-buUduiri.) An opening in a ship's side for the admission of air, closed in stormy weather by a shutter. Air'-sheift. A shaft in a mine, usually vertical, or nearly so, by which the mine is ventilated. Air'-spring. An elasric device dejiemling for its action upon the tension of an imprisoned body of compressed air. Air-springs have been made to act as brakes, to receive recoil of guns, as buffers, and for other pur poses. See Pxeumatic Spring. Fig. 116. Air'-stove. A heating stove which is eni|>loyeoint of mercury, air-themioraeters are used. Dit air, when conftueil, increases in volume g for every 180°, and is believed to be perfectly etjuable in its rate of expansion. A bulb or cylinder with a tube of platinum is connected to a glass tube at right angles therewith. The glass tube is of uuifonn bore, is filled with mercury, and terminates below in a recmn'ed bulb. The glass tube is dividetl into a number of spaces, each e«iuiralent to f of the total volume of the platinum bulb or cylinder, with % of its stem. The other J is supposeil to be beyond the immediate influence of heat. The platinum bulb and § of its stem are plunged in the furnace, and the depression of the mercury by the heatetl and expanded air within the instrument pressing on it more powerfully than the external air, will indicate the degree of temperature. Each degree of the glass stem is equal to ISO' Fah. Air'-trap. Sometimes called deaeh-trap. It is an adjunct to a vessel of any kind, such as a washbowl, water-closet howl, urinal, or sink, which discharges by pipes or sewers up which a current of foul air is liable to pass. , Some of them are veiy simple in their character, and consist of a water-pan in which is subiiierged the end of the dischai-ge-pipe of the bowl above. This shuts off the pas.sage of air, and an overflow is affortled to the water as it reaches a certain height. Craigie's sink, July 2, 1867, is of this charac- ter, and its essential feature has been familiar to builders and housekeepers for many years. In the illustration the novel feature is found in the mode of attaching Fig- 118. the trap - cup to the bowl and the ,>»mmwm \ Tucker's Alarm- Tilt. sounds the gong. By raising the trigger E the drawer may be opened silently. A-laxm'-Twatch. An instrument, not necessarily a timepiece, with going works, and adapted to run down and si-md an alarm after a specific interval of time. See W.^tch .Al.^rm. Al-ba'ta. (jerman silver, comjwsed of nickel, cojiper, and zinc ; with the addition of small quan- tities of lead or iron in some formulas. It is a white alloy, used for taWe-ware, etc., and resembles the Chinese Packfong, or white copper. The following are some of the foi-mulas : — Common, Nickel, 4 ; Copper, 20 ; Zinc, 16. Better, " 6 ; " 20; " 10. For rolling, " 25 ; " 20; " 60. For casting, " 20 ; " 20; " 60 ; Lead, 20. Packfong, " 31.6 ; " 40.4; "25.4; Iron, 2.6. See .\l.I.OY. AVber-type. (P/iotoyr.) The process is as fol- lows : "A plate of glass is covered with a solution of albumen, gelatine, and bichromate of potash, dried and exposed to light until haidened. It is then again covered with a solution of gelatine and bichromate of potash, and when diy exposed under the negative, and the film is then found to possess (jualitics analogous to a drawing made with fatty ink upon lithograph stone. All those jiortions of the film that were acted upon by the light will le- luse water and take printing-ink, while those por- tions which were protected from liglit by the nega- tive will take water and refuse ink. The ink and water will be absorbed liy the lihn just in accordance with the gi'adations of light and shade in the nega- tive. To produce a jiicture, wet the sniface of the film, then apply ink, lay on pa]ier, and pass through a press ; the oj.eration being substantially the same as lithograjihy. The process is said to be rapid, and excellent pictures of all sizes may be printed in aihnirable .style." — r/ir/injr, jiliic Sews. Al bo-lite Cement. Invented by Riemann. Mix calcined and finely inUverized magnesite (na- tive carbonate of magnesia) with infusorial earth, and stir in chloride of magnesium. Among the projierties of the cement, as envmerated by the inventor, are a high degi-ee of jilasticity, and of hardness after it has become fixed, and a spontane- ous develo] nient of heat as scon as it is solidified to the consistency of wax, this increasing in propor- tion to the size of the mass into which it has been molded. It is extremely haid, a peculiarity in- creased by its elasticity, and adlieres very well to stone, wood, and drj' oiled surfaces, but cannot be used under water. It is now largely employed in the preparation of ornamental moldings, for which, however, in consequence of the above-mentioned development of heat, gelatine molds must be cau- tiously used. By coating oinaments of gypsum with this cement it imparts to them a great degree ALBUM. 58 ALCOHOL ENGINE. of h.inlness. It is also used for rciiairiiig woiii- doH'u sandstone stepsj for facing stone ami wooden steps, for lire-proof coating to boards in tlie interior of houses, and also for preserving railroad-ties, eti. Al'bum. A book arranged to lioiil pliotogiaphs, autographs, or memorial addresses of a private char- acter. The principal concern of the mechanic arts with ihe album is with devices for sewing the leaves in the book, making the slip-pockets for the recep- tion of cards, clasps, and securing devices for the leaves of the cover. The utham was originally the tablet on which the Roman prastor's edi(^t was written. It was white, and hung up as a bulletin-board in a public place. It is now a book of triendly memorials : signa- tures, prose or poetic effusions, or photographs. It dates back to the church blank-book, or wAite-page book, in which were inscribed the names of bene- factoi-s of the church, in order that the appointed prayers might be made as the feast-days of their chosen saints recurred. The Venerable Hede, in his preface to the Life of St. Cuthbert, A. D. 7"21, speaks of the record of the saint's name in the albu»i at Lindisfarne. The name frequently occurs in ecclesiastical and other writings. Al'bu-men Process in Photography. This process antedated the collodion, which is much more sensitive. It was invented by Niepce de St. Martin. The g'.ass receives a coating from a solu- tion of albumen to which bromide and iodide of potassium and a drop of caustic potash have been added, and after drying is exposed to the fumes of iodine. It is then silvered in a bath of nitro- acetate of silver, and dried. After passing again over the vapor of iodine it is ready for the camera. The image is developed by a solution of gallic acid, and fixed by a solution of fajTiosulphite of soda. — Maijnll. Al'oar-ra'za. A vessel of jiorous earthenware used for cooling the contained liquids by evaporation from the e.xterior surface. See Ice-m.\chine. The word is Arabic, and the device was introduced into Europe by the Spanish Saracens. Alcan'azas are made of a sandy marl made up into paste with saline water and lightly tired. " In niches where the current of air could be artificially directed hung dripping alcanazas." — Dcscn'pfwn of titc Alhuiiibra. Al'co-hol L.n'gine. An engine in which the vapor of alcohol is used as a motive-power. The first suggestion of the machine was by Rev. Edmund Cartwright at the latter end of the last century. The reason why the elastic vapor of alcohol was supposed to be preferable to that pro- duced from water is that it boils at a tcni]ierature considerably below that of water. It must be recol- lected, however, that all leakage and escape of alco- hol is not alone an absolute loss of a valuable material, but that such leakage is verj' ilangerous, owing to the inllammability of the material. How.\rd's alcohol engine, English patent, 1825, was in use at the Rothcrhithe Iron-Works for some time, but appears to have wearied out the patience or means of the inventor, no engine of that description being now usefully employed so far as we aie aware. The engine referred to was intended to woik up to 24 horse-power. The engine had two vertical cylinders A B, of eijual capacity, connected by a pipe C, at the lower part of each. A quantity of mercury or oil, whiih will not vaporize at the heat to be applied, is placed in each cylinder, so as to fill the base of one and nearly the whole of the other. Within the cylinder J? is a jiiston, exposed above to the pressure of the atmosphere, and packed in the cylinder in the usual manner. In the other cyliniier A is a thin metallic dish D, floating freely upon the surface of the oil. A tube E, terminating in a nozzle pierced with small holes, passes through a stufting-box in the cover of the cylinder A, in whii:h also is a flap-valve G opened by a rod H as Fig. 130. Y V V Ti Hownr/Ts Alcohol Ert^ne. ALCOHOLMETER. 59 ALCOHOLMETEK. occasion requires. The valve is other\vise kept to its seat by a spring. / is the stiilfing-box of the valve-rod ; K the safety-valve. The jiiston has a plug by which a certain quantity of the fluid is admitted above its upper surface, there to remain. N is a discharge-cock, n o are argand-burners, which heat the cylinders -/ B by ilirect action upon their lower surface.*, the hot-air C.ui' extending around them aud terminating in tlu^ cliimney P, which has a register-cap a by which the draft is regii'.ated. By means of a force-pump ]?, worked by the en,Tn •, a small quanti'y of alcohol is drawn from the coiulen.ser and injcc-ted through the pijie E into the dish />. which floats upon the hot oil iu the cylinder A, and is thereby Hashed into steam. The e::|ian- sion of the alcohol depresses the column of oil in the cylinder A, driving it through the passage C into the cylinder B, where it i-aises the piston. Wlien the piston has attained its highest eleva- tion, the valve G is opened aud the vapor escapes by pipe S to the condenser, which consists of an upper and lower chamber connected by pipes V V. These jiipes are surrounded by flannel constantly wetted by water dripping from the trough A', and the evaporation is expedited by a continued draft of air from the rotating fly Z, which is driven by the engine. F is the lower ti'ough, which receives the superfluous water, and /(' is the bottom chamber, which contains the condensed vapor and from which it is drawn by pump E to produce each upward movement of the piston. A cork or wooden pack- ing in the connecting-pipe S prevents the conduc- tion of heat from one p.art of the apparatus to the other. The condensation of the alcoholic vapor causes the return of the oil into the cylinder A, aud the atmospheric pressure causes the piston to de- scend, c, b, are the pipe and stop-cock by which the atmospheric contents of the condenser are with- drawn, preWous to starting the engine, d is the discharge-jiipe Fig. 131. __rVi^-~\ by which the condensermay be drawn from the chamber »'. / is the pijie at which the chamber W is charged with alcohol. It is closed by a screw - pipe when the ma- chine is in ac- tion. Al'co-hol'- me-ter. A modification of the hydrome- ter, for the purpose of as- certaining the comparative specific gravi- ty and conse- quent amount of alcohol in spirituous liq- uors, etc. This instrument may either be so constructed as to be sunk, by weights, to OutlCs Atcofiolmetn. a uniform depth in the liquor testrd, or it r-.r.y indi- cate the gravity by the amount of its sulimergencc, r.3 shown on a giaduated stem, taking either pv.rc alcohol or " proof" as a standard ; the latter mode of construction is more convenient in practice, and more generally adopted. The absolute percentage of alco- hol, or the degree above or below proof, is deduced from tables constructed for that purpose and corre- sjiouding to various temperatures of the lic|uid. GuTH, June 28, 1859. In this alcoholmeter tlie evaporation of a fixed quantity of alcoholic fluid is m?.de to exhibit the exact percentage of alcohol con- tained in the said liquid. While the tube E is yet detached from the apparatus, it is partially filled with mercury, and then receives a definite amount of the alcoholic liquid to be tested. AVhen in- verted and placed in position in tlte instrament the liquid and mercury change places, the foimer occu- j'ying the upper part of chanil er E. Heat being applied, by means of the spirit-lamp B, to the water in chaml er C, the vapor rising therefiom, fiUin;; chamber D, heats the mercury and the alcoholic liqrid, the temperature being indicated by the thcimcmeter A. As alcoholic vapor is elinunated from the liquid it presses upon the coh.um of mer- cun-, causing it to rise in the stem O, :.nd the height of il'.e column against the graduated scale indicates the amount of spirit. The ebullition alcoholmeter of ViP.M. is founded upon his discovery j,. jjg that the boiling tem- perature of alcoholic liquors is propor- tional to the quan- tity of alcohol con- tained in them. It consists of a spirit- lamp, beneath a sn.all boiler, into which a large cylin- drical glass bulb is plunged, having an. upiight stem of such caliber that the quicksilver con- tained i:i them may, by its expansion and a-scent when heated, raise before it a little glass f.oat in the stem, which is con- nected by a thread with a similar glass bead that hangs in the air. The thread passes round a pul- ley, which, turning with the motion of the beads, causes the \ index to move along the gi-aduated circu- lar scale. The numbers on this scale represent percentages of abso- lute alcohol ; so the number opposite to which the index stops, when the liquor in the cylinder over the lamp boils briskly, denotes the percentage of alcohol in it. Sieme.n's alcoholmeter, Berlin, 1869, is thus described: "As the spirit — no matter of what strength — leaves the still, it passes into a cylin- drical vessel, and from this, through a drum some- thing like that of an ordinary gas-meter, into the EbuUiticm Alcoholmeter. ALCOVE. 60 ALKALIMETER. cask which is to contain it. On its way through the apparatus it is measured, gaged, and regis- tered witli the greatest possible e.xactness. First, its bulk or volume is measured and indicated in gallons and di«ijnal parts ; and, second, the (puin- tity of either absolute alcohol or of proof-spirit which it contains is measured and indicated inde- pendently. The measurement and registration of the total bulk or quantity of spirit which passes over is obviously done directly by the rotation of the drum, each of the tliree divisions of which holds exactly five gallons. The indication of the strength of tlie spirit is done by a swimmer in the cylin- drical vessel into which th'' alcohol first enters as it leaves the still. This swimmer is attached to a Jiointei', which, in being elevateil and depressed by the loweiing or rising of the swimmer, according to the varying specific gravity of the liipud, Ihnits the rcciprojating movem,Mits of a graduateil tongue in connection with the counter-work. Thus, not only do the distiller and the exciseman know at a glance ho.v nuieh spirit in total has been distilled within a given time, but likewise ho.v much proof-spirit it is eip.iivalent to. — Eiuiiiicer. See also Liquid-.meteu. Al'cove. (Architecttire.^ A recess separated from a main chamber by columns, anta;, and balusters. A recess in a room for a bed or for seats. A-lem'bic. The hcail or cap which is placed upon the cucurbit, and which discharges by its beak into the receiver. The cucurbit contains the liquid to be distilled, and the alembic is luted thereto to Fig. 133. prevent the escape of vapor which is raised by the heat of the fire, and is conducted to the receiver to he condensed. Some alembics have an aperture in the head to admit material to the retort when the .stopper is temporarily removed. We are indebted to the Arabs for this apparatus and its name. Zozimus, who flourished aliout A. D. 400, described the operation of purifying water by distillation. Djafar, the great Arabian chemist, about A. D. 875 discovered nitric acid, which he obtained by the distillation in a retort of Cyjirus vitriol, alum, and saltpeter. He obtained aqua-regia by the ad- dition of sal-ammoniac, and no doubt felt that in obtaining a solvent of gold he had discovered the long-dcMred aurain potabilc. Rhazes, the Arabian, born 860, obtained absolute alcohol by distilling spirits of wine with (]uicklinie, Achild Bechil, of the same people, distilled to- gether an extract of urine, clay, lime, and powdered charcoal, and oljtained phosphorus. A blind-iihmbic is one having a capital with no rostrum. A-len'<5on Lace. Also called blonde. A variety of lace funiiiil uf two threads, twisted and woikcd to 11. hexagonal mesh. Alcni;un jioiiil is formed of two threads to a pillar, with octagoiKi' and srjuare meshes altern.ately. Al'eu-rom'e-ter. The name given to an instru- ment invented about 1849, by M. Boland, a Parisian bakiM-, for detennining the quality of the gluten ir. different specimens of wheaten flour, and their consequent adaptation for bread-making. A tube of about six inches in length is divided into two parts, of which the smaller one, about two inches in length and holding a given amount of gluten, is screwed on to the longer tube, wdiich is fitted with a piston having a graduated stem. The apparatus is then exposed to a moderate degree of heat, when the gluten expands, forcing up the piston, tlie amount of exjiansion being inilicated by the distance the stem protrudes from tile tube. It was found that gluten obtained from flour of good quality would expand to four or five times its original bulk, and had the smell of warm bread, while that of bad flour became viscid, with a tendency to adhere to the tube, and in some instances emitting an unpleasant odor. Al'i-dade. (Optical Instr. ) The movable arm of a graduated instrument carrying sights or a telescope, by which an angle is measured from a base line ob- ser\'ed thiovgh the stationary or level line of sights. Used in theodolites, astrolabes, demicircles, and numerous other angulonieters. A-lign'ment. {Engineering.) The ground plan of a mad or earthwork. Al'ka-lim'e-ter. The object of this instrument is to ascertain the value of the alkalies of eonunerce. It was invented by Dr. lire, about 1816, or by Mr. Descroizelles, and consists essentially of a graduated tube closed at one end, each graduation correspond- ing to a sufficient quantity of sulphuric or other acid to neutralize a given cmount of pure soda or potash dissolved in water. The strength of the alkali is inferred from the amount of acid required to neutralize it. The instrument recommended by Dr. Faraday consists of a burette supported upon a foot and graduated into one liundred equal parts, j..^ -g. the space between each two of the divis- " ions being capable of containing ten grains of distilled water. The upper part of the instrument is shaped, as shown in the figure, for the convenient introduction of the test acid and its subsequent delivery in drops. To employ it for estimating the amount of carbonate of potash in any sample of pearlash, weigh out 100 grains of the ash, dissolve them in boiling water, so that, when cool, the mixture has a spe- ciiic gravity of 1.1268. Filter if neces- sary, and tinge blue with infusion of litmus ; thi'n fill the alkalimeter to 65 with the test acid, diluting with water to <>', and add the diluted acid grad- ually and cautiously until the reddening efl'eet is ]U-oduced upon the dissolved sample. The number of measures of acid required represents the percentage of carbonate of jiotash in the sample. ^ To estimate the amount of potash con- jinaiimeler. tained in the sample, either as caustic potash or carbonate of potash, fill the alkalimeter to f-^ '^ ; E — ; 10 = 20 - 30 i 40 SO J 00 i ^ 70 ; = 1 - 1 r dO I -' ! ^ 90 'M 1 ALI^ALONG. 61 ALLOY. 49 «-ith the test acid, the 100 measures being again made up with water. The number of divisions of this dilute acid required to neutralize 100 grains of the sample will correspond to the proportion of pure potash in the sample. For the detemiination of carbonate of soda, the alkalimeter must be filled to 54.6 witli the test acid, which must then be used as before. For the esti- mation of caustic soda, the operator will require to fill the instrument to 23.4. . The nvmiber of meas- ures required to change the blue of the solution to red will in both cases correspond to tlie percentages of caustic or carbonated alkali required. All-a-long'. A bookbinder's te:m to denote that the sewing-thiead pas.ses from end to end of the fold, or directly between the distant points of punctura- tion. Allege. (/")•.) A balla.=t-boat. Al-lette'. {Archilcchire.) A wing of a building ; a bu'tress or pilaster. Alley. (.Printing.) The compositor's standing- plai-e lietween two opposite frames. Al-loy'. An alloy is a combination by fusion of two or more metals, as brass and zinc, tin and lead, silver and copper, etc. Many alloys are composed of definite chemical ' proportions of their component metals, whilst in others the metals unite in any proportions. The best-kno^vn and perhaps the most generally useful alloy is brass, which is formed bj- the fusion together of copper and zinc. The Colossus at Rhodes was said to have been constructed of brass B. C. 288. Bronze is a much more ancient alloy than brass, and has been known from a verj* remote anti(|uity. See Brass and BiiONZE. All alloys are opaque, have a metallic luster, are more or less elastic, ductile, and malleable, and are good conductors of heat and electricity. Those consisting of metals of very ditTerent degrees of fusibility are usually malleable when cold and brittle when hot. Metallic compounds containing mercury are amalgams. Metals do not imite indif- f'r.'Utly with each other, but have certain affinities ; thus silver, which will hardly unite with iron, com- bines readily with gold, copper, or lead. Alloys are generally harder and less ductile than the mean ol' their constituents, and their specific gravity is usu- ally either greater or less than this mean. (See Ta- ble. ) The melting-point of alloys is usually below that of either of the simjile metals composing them ; thus, an alloy of 8 parts bismuth, 5 lead, and 3 tin, fuses at the heat of boiling water, or 212°. See Fusible Alloys. They very frequently possess more tenacity than their constituents would seem to indicate ; thus an alloy of 12 parts lead and 1 part zinc has double the tenacity of the latter metal, or about six times that of lead. They are, in general, more easily oxidized than their component metals. An alloy of tin and lead unites with oxygen so readily as to take fire and bum when heated to redness. A very slight modiSation of the components of- ten produces a great change in the mechanical prop- erties ; brass, containing two or three per cent of lead, is most readily turned, but works badly under the hammer, while that of the best quality for ham- mering is not turned with facility, owing to its toughness. The precious metals, when employed for coin or jewelry, are invariably alloyed to increase their hardness ; the degree nf finenes.s, or proportion of pure metal, being usually estimated in carats or twenty-fourths. In this case the term ' ' aUoj " >s often understood to apply merely to the baser metal with which the gold or silver is combined. Thus the British standard for gold is 22 parts pure gold and 2 parts alloy, or 22 carats fine ; for silver, 222 parts pure silver and 18 parts alloy. The alloy for gold is an indefinite proportion of silver and copper ; that for silver is ahvaj's copper. The standard for silver plate is the same as foi' coin ; that for jeweler's gold is 18 carats, but I'or some pur- poses the fineness is reduced to 12 and even 9 carats ; silver is used for the alloy, and copper may be added to heighten the color. Silver and palladium unite in any proportions, and it has been found that this alloy is not so readily tarnished as silver ; it has been used for the gi'adu- ated scales of mathematical instruments. Platinum has been used with silver for similar purposes, but requires greater care in fusion to make the combina- tion. Steel is much improved for cutlery by being al- loyed with about jj^ part of silver ; it is a'so im- proved by 5^ part of platinum. From one to two per cent of rhodium has also been combined ^^ith steel, with excellent results. BRASSES AXD BRONZES WITH THE ADDITION" OF IKON. 1 u o c •6 "3 1 J_ 1 J .a 55 Ancient Bronze Sword, Ireland 83 JO 515 3.0 S.35 Ancient Kronze Sword, Thames, England . 89.69 9.58 0.33 Ancient Bronze Ase- head, Ireland . 89.33 9.19 0.33 Ancient Bronze Wedge, Ireland 94. 5.9 0.1 Ancient Bronze Knife, Amaro, South Amer- ica .... 9.5.66 3.96 0.37 Coin of Hadrian 8.5.67 1.14 10.85 .74 1.73 *' " Tacitus . 91.46 2. .31 " *' Probus 90.68 2.00 1.39 .61 2.33 2 29 94.65 .45 .80 .45 3 22 " " Pompey 74.17 8.47 .29 16.65 ChiQe.«e Whit* Copper ( Packfong) 40.4 25.4 2.6 31.6 Keirs Metal, English Patent, Dec. 10,1779100. 78. 10. 1 Keirs Metal, English o Patent (another for- mula) 100. 80. 10. 40. Tractable Yellow Metal (old formula) . 55.33 41.8 4.06 Font;tinemore-iu*p Eng- lish Patent, 18:38 . 8. 90. 1. Cutler's EngU.-^h Pat- ent, IPS'* 16. 5. 3. .5 Sorei's White Bra.'^s, \m). 10. ,80. 10. Parke's English Pa^ ent, 1S44 91. 21. 45.5 45.5 Parke's Enjrli>=h Pat- 1 ent (anotner for- 1 mula) 45 128. 67. 2.5 Parke's English Pat- 1 ent (another for- 1 mula) 3. 48. 50. 1. Stirling's Gun -Metal, bb English Patent, 1846 50. 25. 1-8 p e9 Stirling's " British s Gold," English Pat- ent, 1846 400. 93. 7. 6. Bell-Metal (Overman) . 71. 26. 2. 1. Aich's Metal, English Patent, Feb. .3. I860 60. 38.125 1.5 Rosthom's Gun-Metal, Austria, 1861 . 55.04 083 42.36 1.77 Rosthom's Gun-Metal (another analysis) . 57.63 0.15 40 22 1.86 Xavy Brass, Au.*;tria 60. 38.12 1.8 Parisian Clock Bells . 72. 26.6 1.5 Birkholz Metal, United States Patent, Mar. 11,1862 . 60. 38. 2. ALLOY. 62 ALLOY. An English work of 1853 cites tlip aJilition of one to two per cent of iron to brass to give strength arcl sonorousness; and furtlier slates th:it "large guns, large screws, propeller-vanes, niill-hiTisses, raihv:iy-bearings, bells, and other articles are made of a metal in which copper, zinc, tin, and iron, all taler like lead, and is so soft that it may be scratched with the nail, but it will not foul a saw or file. The second alloy is made by melting together in the same way 1 ]iart of tin with 1.25 ]iarts of lead. This alloy is less clastic and harder than the fore- going. It is rather brittle, less malleable than the former, and fills up a file. Neither of these alloys was acted on by boiling with acetic acid lor half an hour, and standing in tlie acid for twcnty-lour hours longer, nor had salt-water any action upon them : hence they may be useful for some kinds of utensils. VIGOUROUX S ALLOY FOR EEER-TArS. For the body . " •' key Or . Tin. 785 807 715 Antimony. Nickel. 195 176 216 20 18 I 70 i Cock-metal is an alloy of copper and of lead for faucets. Metallic injection for anatomical preparations : — Bisnmth . . .1 Lead ... 1 Tin ... 1 with the addition of a small amount of mercury. ALLOY. GS ALLOY. H.i.CKBitT's patent, May 17 ind hardware : — Copper Arsenic Cream of Tartar lS6i. For knobs . 3 3 . 2 Pfeiffer's patent, August 14, 1S66 : — Lead ... 98 Copper ... 1 -Tii . . . S Antimony . . J Bismuth . . . i Hood's alloy for ship's bolts (England, 1844) :-■ (Topper . . .40.4 Zinc ... 3.8 Lead . . - 16.5 Antimony . . 5.1 STRrBiXG's box metal for bearings (Engl., 1849) : Zinc . . .75 Tin . . . 18 Lead . . . 4i Antimony . . 24 (Oreide.) An analysis of this new compound by a German chemist gives the following : — Copper . . . 79.7 Zinc . . . 13.5 Nickel . . .6.09 Iron . . . 0.28 Tin . . . . 0.09 The two latter he regarded as mere accidental ingiedients. According to another formula oreide consists of Pure Copper . . 100 Zinc or (preferably) Tin 17 Magnesia . . 6 Sal-ammoniac . .3.6 Quicklime . . 1.8 Tartar of Commerce . 9 See Or-eide. An alloy for silver com, etc., upon wliicli experi- ments have been made iu France, and which is said to render the metal more homogeneous than the com- mon alloy of pure copper, less liable to be tarnished by sulphureted hydrogen, and wliich, when tough- ened by continued rolling, may be restored by sim- ple heating, is as follows : — Copper ... 93 Zinc ... 72 To be added to Silver . 835 Magee's allov for moldboards of plows. Septem- ber 9, 1871. Copper .... 85 Tin . . . . 12 Zinc .... 3 Aluminium bronze, consisting of copper 90, alumin- ium 10 per cent (Ijy weight, we suppose), lia-s been stated to have the strength of cast-steel ; a state- ment apparently confirmed by Mr. Anderson of the Royal Gun Factory' in England, and by the experi- ments of Mr. Morin, Xanterre, whei-e it was found that the tensile strength of this metal is of 5,323 kilogrammes to the square centimeter. At the same time a very important point was determined, — the transverse strength or resistance to being bent. Tliis was found to be for bi-ass, 2.22; gnn-nictal, 0.15 ; .aluminium bronze, 0.05. Tli.-vt is to say, tliree eijual bars of these lUtferent metals were fastened at one end so as to l>e perfectly horizontal, a ceitain 5 equal weight was placed at the free end of each bar, and the result measured by an instrument for that purpose. Brass bent at 2.22 degrees of the instru- ment, the other metals a.s indicated above, thus showing the resistance of aluminium bronze to be 44 times greater than brass. The transverse strength, the resistance to permanent flexion, resistance to friction, and the superior resistance to oxidation dis- played by this metal, although the latter quality lias" not yet been accurately detennined, admirably qualify it for delicate mechanism anil also for pur- ])0ses Where hardened steel wa.s entirely employed. The tenacity of this alloy is astonishing, and is hardly equalled by any other metal ; it is more diflicult to cut than gold or brass, but the cut is veiy clean and smooth. The alloy of iridium and osmium, called iridos- minc, is the hardest of all alloys, and is used for pointing the Hawkins " Everlasting Pen " (English). Miclon, of Paris, proposes a new alloy for the manufacture of all metallic articles, — bells, hammers, anrils, rails, and non-cutting tools. The alloy con- sists of twenty parts of iron turnings or tin waste, eighty pai-ts of steel, four parts of manganese, and four parts of borax ; but these proportions may be varied. When it is desired to increase the tenacity of the alloy, two or three parts of wolfram are added. When the cupola is ready, the iron and steel are poured in, then the manganese and borax, and the vessel is tilled up with coke. A nimiber of other alloys are known and used, including some of E:istcrn origin. The latter are generally of little practical inqiortance. Such are — • Aumm Musivum, same as Mo.saic gold. Clinquant, same as yellow copper ; Dutch gold. Caracoly, composed of gold, silver, and copper. Calin, a Chinese alloy composed of lead and tin. Electrum, an ancient alloy of gold and silver. The following table ati'ords a ready means for the conversion of decimal proportion into divisions of the pound avoirdujTiois. The proportions of metals in formulas for alloys are sometimes stated in one way and sometimes in the other. Dec. of lb. 02 dr. Dec. of lb. .nn.^t7 14 .1797 (KH« 15 .1836 ntB.5 .1875 ()(>« 1 .1914 .0703 2 .1953 .0742 a .1993 n7Sl 4 .2(]31 0R2() 5 .2070 OiiiSt K .2109 0898 t .2148 eft's « .2188 .0977 9 .W7 .mifi 10 .2266 105.5 11 .2305 109+ 12 .2SH li:« 13 .2.3=3 ^M•>. 14 .2422 .1211 15 .2461 1250 2 .2500 Dec. of lb. .2539 .2678 .2617 .2656 .2695 .2734 .2773 .2813 .2862 .2891 .2930 .2969 .3(X)8 .31147 .3086 .312.5 .3164 .3203 .3242 .3281 .&320 AS59 .3398 .3437 .3476 A516 .3.555 x,n .3633 .3672 .3711 .3750 Oi. dr. Dec. of lb. .3867 .3906 .3945 384 .4023 .4062 .4102 .4141 .41.80 .4219 .4258 .4297 .4036 .4376 .4414 .4463 .4492 .4531 .4570 .4609 .4648 .4687 .4727 .4766 .4805 .4844 4883 .4922 .4961 .5000 7 10 7 11 7 12 7 13 7 15 I 8 ALLOY. C6 ALLOY. It is lielieved that alloys are more perfect when oompounileil aecordin;,' to atomic yvoportions, or by multiples of their elieniieal eipiivnluiits, instead oi' by yiiliiiiies. Tlie eheiiiie.il eip.iivaleiits of tlie metals upon the hydrogen .scah-, now mo.it iisiially adopted, are appended to the Ibllowing list of metals ; — Aluminiuin(about) Antimony Arsenic Biiiiiiuth Cadmium . Uohalt . Copper Gold . Iron (wrought) Iron (cast) . Lead Manganc-5e . Mercury (boils at) Nickel . Palhulium Platinum Rhodium . Silver . Tin . Zinc Melting- poiut. 70U°I 800 500 442 25(10 21100 2016 3280 2786 612 2700 670 2500 hardly fusible Speeitic Gravity. 1873' 442 77^ 2.5fi 6.712 5.8 9.822 8.011 8.03 «.SU 10.3 17.6 7.807 11.44 6.85 13.5 8.27 113 21,5 11.0 10.4 7.28 68 Chemical Equivalents. (cast) (cast) 13.75 64 .6 87 7 71,0 55.8 29.5 31.6 199.2 28. 28. 1036 27 7 202.0 29.5 53,3 98.8 62.2 108.0 57.9 32.3 For a more comidete list see Ato.mic Weights of IIetals ; Mei-als. Alloys of greater Specific Gold aiiTl Zine. Gold and Tin. Gold and liismuth. Gold and Antimony. Gold and Cobalt. Silver and Zinc. Silver and Lead. Silver and Tin. Silver and P.ismuth. Silver and Antimony. Alloys hariii^ a Specific Gohl and Silver. GoM and Iron. Gold and Lead. Gold anil ('o]iper. Gold and Iridivnn. Gold and Niekel. Silver and (.'i)pper. Copper and Lead. Grnvit'f than tlie Mtnii of llieir Com- ponents. Popper and Zinc. Copper and Tin. Copper and Palladimn. Copper ami Hismuth. Copper and Antimany. Lead .and Bisnuitli. Lead and Antimony. Platinnmand Molybdennm. Palladium and Bismtith. (rrm-ity uiftrior to the Mean of llieir ConMituents. Iron and Bisnnith. Iron and Antimony. L'on and Lead. Tin and Lead. Tin and Palladium. Tin anil Antiinmiy. Nickel and Arsenic. Zinc and Antimony. (Remarks.) Tlie various propi>rtions and relative qualities a-s to melting-point and gravity are col- lected from a multitude of sowrci.'S, the Ij'est attain- abl(\ The authorities, however, dill'er somewhat widely, and tliis can only be acconnti'd for from the fact that so few metals can be obtained pure. Tlie dillerenccs in the metals obtained IVom ditferent localities arc often unsuspected, and are fully proven in the variable statements of the cohesion in the tables compiled by Muschenbrcek, Tredgold, Barlow, Bi-own, Rumford, Hennie, Telford, Bramah, anil othei-s. Tlie dilticulty that has thus arisen has caused \Mri- able statements in tlie formulas for bell and ordnance easting, and has very c:onsiderably alfectcd the e.vactt- ne.ss of statement in all the alloys, csiiecially the more fusible ones, where tile various combinations of lead, tin, and bismuth give such variable resijts. It appears to be scarcely possible to give any sufficiently general niles, hy whicli the properties of alloys may be safely inferred fi'om those of their constituents ; for although, in many cases, the woiking cpialities and appearance of an alloy may be nearly a mean proportional between the nature and (jnalities of the metals composing it, yet in other and fretpient instances the deviations arc excessive, as will be seen by several of the examples following. Thus, when lead, a soft and malleable metal, is combined witli antimony, which is hard, brittle, and crystalline, in the proportions of i'rom twelve to fifty parts of Jead to one of antimony, a ilexible alloy is obtained, resembling lead, but somewhat harder, and which is rolled into sheets for slieath- ing shi])s. Six parts of lead and one of antimony are used for the large, soft ininters' types, which will bend slightly, but are considerably liardcr than the Ibregoing ; and three jiarts of lead and one of antimony are employed for the smallest types, that are very hard and brittle, and will not bend at all ; antimony being the more expensive metal, is used in the smallest quantity that will suflice. The diH'erence in specific gravity between lead and antimony constantly interferes, and unless the type- metal is frequently stirred, the lead, fioni being the heavier metal, sinks to the bottom, and the anti- mony is disprojiortionally used from the surface. In the above examples, the ditl'erences aiising from the proportions appear intelligible enough, as, when the soft lead ]U'evails, the mixture is much lilce the lead ; and as the hard, luittle antimony is increased, the alloy becomes hardened and more brittle ; with the proportion of four to one, the fracture is neither reluctant like that of lead, nor foliated like anti- mony, but assumes very nearly the grain and color of some kinds of steel and cast-iron. In like man- ner, wlien the tin and lead are alloyed, the former metal imparts to the mixture some of its hardness, whiteness, and fusibility, in proportion to its quan- tity, as seen in the various rpialities of pcHter, in which, however, copper and sometimes zinc or anti- mony are found. The same agreement is not always met with ; as nine jiarts of copper, which is red, and one part of tin, which is white, both very .malleable and ductile metals, make the tough, rigid metal used in brass ordnance, from which it oljtains its modern name of gun-metal, but which neitlier admits of rolling nor drawing into wire ; the same alloy is described by Pliny as the soft bronze of his day. The continual addition of the tin, the softer wc/i'i/, ]ii'oduccs a gradual increase of hardness in the mix- ture ; with about one sixth of tin the alloy assumes its maximum hardness consistent with its application to mechanical uses ; with one fourth to one third tin it becomes highly elastic and sonorous, and its brit- tleness rather than its hardness is greatly increased. When the cojiper becomes two ]iarts, and the tin one jiart, the alloy is so hard as not to admit of be- ing cut with steel tools, but crumbles under their ac- tion ; when struck with a hammer, or even suddenly warmed, it Hies in pieces like glass, and clearly shows a structure highly crystalline, instead of mal- leable. The alloy has no trace of the red color of the cop])er, but it is quite white, suscejitible of an exquisite polish, and, being little disposed to tarnish, it is most perfectly adapted to the reflecting specu- lums of telescopes and other instruments, for which purpose it is alone used. Copper, when coniliined in the same proportions with a tlill'erent metal, also light-colored and fusi- ble, namely, two parts of cop]ier with one of zinc (which latter metal is of a bluish-white, and crys- talline, wliereas tin is very ductile), makes an alloy of entirely oiiposite character to the speculum ALLOY. 67 ALLOY. metal ; name!)-, the soft j-ellow brass, which be- comes by hammei-ing very elastic and ductile, aud is very easily cut and tiled. Again, the same proportions — namelj', two parts of copper and one of lead — make a connnon infeiior metal, called jiot-metal, or cock -metal, from its employment in those respective articles. This alloy is much softer than brass, and hardly possesses malleability ; when, for example, the beer-tap is driven into the cask, immediately after it has been scalded, the blow occasionally breaks it in pieces, fiom its reduced cohesion. Another proof of tlie inferior attachment of the copper and lead exists in the fact that, if the molds are opened before the castings are almcst cold enough to be handled, the lead will ooze out, and appear on the surliice in globules. This also occure to a less extent in gun-metal, which shouhl not on that account be too rapidly exposed to tlie air ; or the tin strikes to the surface, as it is called, and makes it particularly hard at those parts, from the proportional increase of the tin. In casting large masses of gun-metal, it frequently happens that little hard lumps, consisting of nearly half tin, work up to the surface of the runners, or pouring-places, during tlie time the metal is cooling. In brass this separation scarcely happens, and these molds may be opened whilst the castings are red-hot without such occurrence ; from which it appears that the copper and zinc are in more per- fect chemical union than the alloys of copper with tin and with lead. The malleability and ductility of alloys are in a gi-eat measure referable to the degrees in which the metals of which they are respectively composed possess these characters. Lead and tin are malleable, flexible, ductile, and inelastic whilst cold, but when tlieir temperatures much exceed about half-way toward their melting- heats, they are exceedingly brittle and tender, owing to their reduced cohesion. The alloys of lead and tin partake of the general nature of these two metals ; they are flexible when they are cold, even with certain additions of the brittle metals, antimony and bismuth, or of the fluid metal, mercury ; but they crumble with a small elevation of temperature, as these alloys melt at a lower degree than either of their components, to wljich circumstance we are indebted for the tin solders. Zinc, when cast in thin cakes, is somewhat brittle when cold, but its toughness is so far increased when it is raised to about 300° Fah. that its manu- facture into sheets by means of rollers is then admissible ; it becomes the malleable zinc, and ' retains the malleable and ductile character in a moderate degree, even when cold, but in bending rather thick plates it is advisable to w-arm them to avoid fracture. When zinc is remelted, it resumes its original crystalline condition. Zinc and lead will not combine without the assistance of arsenic, unless the lead is in very small quantity ; the arsenic makes this and other alloys very brittle, and it is, besides, dangerous to use. Zinc and tin make, as may be sup]K)sed, somewhat liard and brittle alloys, but none of the zinc alloys, except that with copper to constitute brass, are much used. Gold, silver, and copper, which are greatly supe- rior in strength to the fusible metals above named, may be forged, either when red-hot or cold, as soon as they have been purified from their eartliy mat- ters and fused into ingots ; and the alloys of gold, silver, and copper are also malleable, either red-hot or cold. Fine or pure gold and silver are but little used alone ; the alloy is, in many cases, introduced less with the view of depreciating their value, than of adding to their hardness, tenacity, and ductility. The processes which the most severely test these qualities, namely, drawing the finest wires, and beating gold and silver leaf, are not per- formed with the pure metals, but gold is alloyed with copper for the red tint, with silver for the green, and with both for intennediate shades. Silver is alloyed with copper only, and when the quantity is small its color suH'ers but slightly from the addition, although all its working qualities are greatly improved, pure silver being little used. The alloys of siuiilar metals having been consid- ered, it only remains to observe that when dissimi- lar metals are combined, as those of the two oppo- site gi'oups, namely, the fusible lead, tin, or zinc, with the less fusible copper, gold, or silver, the malleability of the alloys, when cold, is less than that of the superior metal, and when heated barely to redness they fly in pieces under the hannner ; and therefore brass, gun-metal, etc., when red-hot, nmst be tieated with precaution and tenderness. JIuntz's patent metal, wliich is a species of brass and is rolled red-hot, apjiears rather a contradiction to this ; but in all probability this alloy, like the ingots of cast-steel, recjuires at first a very nice attention to' the force ajqdied. It will be also remembi red the action of rollers is more regular than that of the hammer, and soon gives rise to the fibrous character, which, so far as it exists in njetals, » is the very element ol' strength, when it is uniformly distributed throughout their substance. The strength or cohesion of the alloys is in general greatly superior to tlnit of any of tlie metals of which they are composed. For example, the relative weights which tear asunder a bar of one inch square of the several substances stand as follows, — all the numbers being selected from JIuschenbrcek's valuable investigations, so that it may be presumed the same metahs, and also the same means of trial, were used in every case : — AUoys. Cast Metals. lbs. lOCoppcr, lTin,32,0;i3 8 " 1 " 3';,li.S8 6 " 1 " 44,071 4 " 1 " a5,739 2 " 1 " 1,017 1 '• 1 " 725 lbs. Barhary Copper, 22,.'j70 .lapHu " 20,272 Eiifrlish Block Tin, 6,l»0 " •• 6.322 Banca Tin, 3,H79 Malacca Tin, 3,211 The inspection of these numbers is highly con- clusive, and it shows that the engineer agrees with the theory and experiment in selecting the propor- tion six to one as the strongest alloy ; and that the optician, in choosing the most reflective mixture, employs the weakest but one, its strength being only one tliird to one sixth that of the tin, or one twentieth that of the copper, which latter constitutes two thirds its amount. See HoltzapllVl's " Turning and Mechanical Manipulation," Art. "Alloys." It is much to be regretted that the valuable labors of Muschenbrrek have not been followed up by other experiments upon the alloys in more general use. One curious circumstance will be observed, how- ever, in those which are given, namely, that in the following alloys, which are the strongest of their re- spective groups, the tin is always four times the quantity of the other metal ; aud they all confirm the circumstance of the alloys having mostly a greater degree of cohesion than the stronger of tlieir comixinent metals. ALMADY. 68 ALTISCOPE. Alloys. Cast Metals. lbs. 4 English Tin, 1 Load, 10,fi07 4 Itiiiica Tin , 1 Antimony, 13,48IJ 4 " ■■ 1 liisniutli, li;,illl2 4 Knglish Tin, 1 Hoslar Zinc, 111,268 4 " " 1 Antimony, 11,3^3 lbs. Lead, 885 Antimony, l,llf)0 Zinc, ■2,IJS'J liismuth, 3,IW8 Tin, 3,:ill to «,i)!;0 For otlirr matter in i-pgai-il to metals, see Metals. The varii-tie.s of alloys afe considered under their specihod heads as follows : — Aich's metal. Oieide. AUiata. Patklbiig. Aluniiiiinm bronze. Parisian gold-colored al- Argeutum nio.saicum. loy. Artiiiiourantico. Parisian white metal. Auruin niosaicum. Petong. Babliilt metal. Pewter. Bath metal. Pewterer's solder. Bell-metal. Pewterer's temper. Biddery ware. Plumber's solder. Billon. Pot-metal. Blanched copper. Queen's metal. Brass. Red brass. Britannia metal. Red tombac. Bronze. Kosthorn's gun-metal. Calin. Sabot metal. Caracoli. Semilor. Climiuant. Sheathing-metal. Electrum. Shot-metal. • Expanding alloys. Silver-solder. Fusible alloys. Soft solder. German metal. Solder. German silver. Spanish tutania. German stei'l. S|ieculum metal. German tutania. Spelter solder. German white copper. Statuary brass. Gold-solder. Stereotype metal. Gun-metal. Tinman's solder. Hard solder. Tonitiae. Imitation gold. Tula metal. Journal-box metal. Tutenag. Manheim gold. Tvpe-metal. Minargent, White brass. Mock gold. White malleable alloy. Mock platinum. White metals. Mo(dc silvei-. AVootz. Mosaic gold. Yellow metal. Muntz's metal. Al'ma-dy. ( Vessel. ) An African canoe made of the bark of trees. APman. (Mrlitllnreiit.) A furnace used by refin- ers for .M']iaratiiig metals. See Aljiond-furnace. Al'mond-fur'nace. The word is pi-obably cor- rupted from Jig- 135- Alman (Allc- viandy Ger- man) furnace. A furnace used by refin- ersfor separat- ing all kinds of metals from cinders, etc. Al'-niond- peel'er. A small machine used by con- fectioners and cooks. Wathew's almond - peel- er, UctobcrSU, l"v ■ N Wathew^s Almond-Peeler. 1SC6. The thin peel is removed from the scalded almond kernels by passing them between tw-o elastic bands of India-iubber, traversing side by side in the same direction, at dillerent velocities. Alnmnds came from Persia, and were introduced into England, 1570. Al'mu-can'ter Staff. An instrument haying an arc of 15', fuinierly used to obtain observations of the sun's aiM|ilitude at the time of its rising and setting, to lind the variation of the compass. Al-pac'a. (Fabric.) a. A cloth in which the, wool of the alpaca (a .s|)eeies of the llama, inhabit- ing Peru) is combined with wool, silk, or cotton. b. A soft dress-goods, an imitation of the former ; having a cotton chain and woolen filling, plain color and highly finished surface. Al'pha-bet Tel'e-graph. An apparatus which marks symljols on imper by pressure, as Morse's ; or by chemical action, as Bain's ; or impresses type on paper, as House's or Hughes's ; in contradistinc- tion to one whose indications are observed by the fluctuating position of a needle or needles, as Cooke anil Wheatstone's, or the bell-telegraph of Bright. See Kk.ciiudini: Telegraph. Al-phon'siii. (.S'«)v//ccfi.) A kind of bullet- forceiis. Named from Alphonsus Ferrier of Naples. Al'tar. 1. The low ridge which intervenes be- tween the puddling-hearth and the stack. 2. One of the steps at the side of a graving-dock. The steps are from nine to sixteen inches in hight, and from nine to fifteen inches wide, except the bnmil nltiir, wliirh is eighteen inches wide. Alt-az'i-muths. See Theodolite ; Tuansit. Al-tim'e-ter. An instrument for taking altitudes geometrically, or for measuring vertical angles, as the quadrant, sextaat, etp., or the vertical limb of the theodolite. One of the first references to means for measuring height is in connection with the most worthy arti- ficial object in the world, then or now. Thales is said, by Plutarch, to have been in Egypt in the reign of Amasis, and to have taught the Egj'ptians how to measure the height of the pyramid by its shadow. This is interesting from its association of names and places, but is absurd in itself. Thales went to Egypt to learn, not to teach. During the reign of the same king, Egypt was visited by Py- thagoras and Anacreon, the friends of Polycrates of Samos ; I'ythagoias, among other things, learned to abominate beans, the peculiar aversion of the Egyp- tian priests. Egyjit was also visited about this time by Solon (Herodotus, I. 30), who came as a student, and aiterwarils introduced some of the Egy)itian laws into his Athenian code. Al-tin'car. [.McUiJIurriii.) A factitious kind of salt used in separating metals. Al'ti-scope. Olauk, March 13, 1866. This iin'ention consists of an arrangement of lenses and mirrors in a vertical telescopic tube, by means of which a jierson is able to overlook objects inter- vening between himself and the object he desires to see. When the sections of the tube are extended, the view is received upon an upper mirror jdaced at an angle of 4,5° and reflected thence down the tube to a lower mirror, where it is seen by the ob- sei'ver. The image is magnified by lenses inter- vening between the mirrors. The telescopic tubes are so connei'ted that each in turn acts upon the next in series, as it conies to the end of its own range, and thus the desired elevation is arrived at. Tin' means of extension is a winch and cords. Stevens, Jamtary 6, 1863. This affords a means - for training guns to a given angle with the axis of the vessel, or on an object, while the gunner re- ALTITUDE INSTRUMENTS. 69 ALUMINIUM. mains beneath the gun-deck. There is attached beneatli the deck to the pintle ol' the jiivoted gun a graduati'd inde.x-plate, by which its huiizontal bearing may be read. A telescopic tube, with two rectangular bends and witli reflecting mirrors at the angles, is so placed as to be used from beneath the Fig. 136. Sleven^s AUiscope. deck ; two of these may be so situated as to form a base of sufficient length to obtain, by simultaneous ob-servation, the distance hy triangulation. Two screw-propellers, working in contrary directions, rotate the vessel so as to bring the guns to bear on the required jioiut. The ujiper and lower limbs of the telescopic tube are parallel ; the one above deck is presented towards the object, the other to the eye. The image of the oljject, after being twice reflected, reaches the ej'e of the observer, whose person is not exposed. A portable altiscope, adapted to enable a person to look over the heads of a crowd, is formed of a hollow cane with perforations near its respective ends, opposite two reflectors arranged at angles of 45' in the cane. The cane being held vertically, and the upper orifice presented towards the object to be viewed, — a speaker, for instance, — the image is re- ceived upon one mirror and passes down the cane to the other, where it is observed by the jjerson. Slides cover the openings when not used for observations, and the c-.ww lias thi'ii iiii ordinary appearance. Al'ti-tudelu'stru-meats. Theodolites, sextants, transit instruments, ami many othiTs having spe- cific names, are used for taking altitudes, while some TABLE OF T)1E VISIIiLE D1ST.\XCE OF OBJECTS IX ST.\TUTE MILES. >.583 1. 11 1.31 12 i 1-S.5 13 14 2 1)2 1.') 2.9.3 IG 8.21 17 3 47 IS 1 37 la 1 3.93 20 '■ 4.13 25 .30 a5 40 45 .50 .55 m 70 RO 90 100 s Is .3-^ V a " 7.1S 1.50 7-7G 200 8,3 .300 8.S 400 9 37 .5110 9 72 1000 10.14 2000 11,97 .300fl 1172 4000 12 43 5000 131 1 mile. lfi.05 1S.54 22.7 26^2 29.3 41.45 .5Sfil 71.79 82 9 92.68 95.23 * For a statute mile the curvature = 6.99 inches. of them have also adju.straents in azimuth. These are treated specially imder the above and other titles, and are also referred to under Astkono.mi- CAL iNSTra'.MENT.s. The uUitiide and azimvth circle is used for meas- uring the altitudes and azimuths of stars, as its name implies, and is com- posed of two gi'aduated cir- cles, one verti- cal and the oth- er horizontal. It is thus of genei-al appli- cation. Jean Picard, the great ■5 French astron- omer, 16 20 - 1684, is said to have been the fir.st to apply the telescope in the measure- ments of angles. Al-tom'e- ter. A name for tlie theodo- lite, which see. AI'to-ri'H-e'vo. The high relief of a sculptured object from the plane surface to which it is attached. The degrees of prominence of the object are indicated by the terms : — Alio, or hiqh-rclief, when the object projects more than half its thickness, frecpiently being attached at a few places to the jilane surface. Mezzo, or dcmi-rclirf, less jn'ominent, say one half the thickness or a little less than half. Basso, or low-relief, a slight prominence, as in medals and coins. Al'u-del. A pear-shaped receiver, used in the Spanish furnaces for suliliming mercury. The aludels are fitted together longitudinally in a row, the neck of one fitting into the bulb of another, being luted together at the joints with softened Fig. 137. Mudel. loam. The mercury condenses in the aludels, and gradually works its way to the lower one of the series, which is tapped to allow the metal to flow ofl'. The aludcl funiaee has a vaulted chamber above the fuel chamber, aiid in the former the blocks of cinnabar are built up. The fumes of the metal pass into a number of strings of aluekls, and, being condensed, are received in a common duct which leads to a reservoir. Al'u-min'i-uin. Equivalent, 13.7 ; symbol, Al. ; specific gravity, 2.56 cast, 2.67 hammered; fus- ing-point, 1250° Fah. Next to silica, the o.xide of aluminium (alumina) forms, in combination, the most abundant constitu- ent of the crust of the earth (hydrated silicate of alumina, clay). Common alum is sulphate of alumina combined with another sulphate, as potash, soda, etc. It is much used as a mordant in dyeing and calico-print- ing, also in tanning. I Aluminium is a shining, white, sonorous metal, ALUlllMUM. 70 ALUMIKIUM. having a shade between silver and ])latininii. It is a very lif,'lit metal, being lighter than glass, and only one fonitli as heavy as silver nf the same bulk. It is veiy malleable and dui'tile ; does not oxidize wlieii exjio.-ed to njoist or dry air, is not elieniieally alleeted by hot or eold water. Suliihu- reted liydrogen gas, wliieh so leudily tarnishes silver, forming a blaek lilni on the surl'aee, has no aetion upon tliis metal. AUmiiniuin is of great value in niecdianieal den- tistiy, a.s, in addition to its lightness and strength, it is not all'ecfed Ijy the presence of sulphur in the food, — as by eggs, for instanee. I)r. Fowler, of Yarniouthport, Mass., obtained patents for its combination with vuleanite as ap- I)lied to dentistry anil other uses, Februaiy 7 and 14, IStio. It resists sulphur in the ]irocess of vulcani- zation in a manner whieh rendiMs it an elKeient and econciuiiral substitute for platinum or g(dd. Aluminium is derived iio)n the oxide, alumina, whieh is tlu^ principal constituent of common clay. Lavoisier, a celebrated French chemist, iirst sug- gested the existence of the metallic bases of the earths and alkalies, which fart was demonstrated twenty years thereafter by Sir Humphry Davy, by elinunating jiotassium ami sodium from their combinations ; and afterwards by the discovery of the metallic bases of barytes, strontium, and lime. The earth alunnna resisting the aetion of the vol- taic jiile, and the other agents then used to induce decomposition, twenty years more ])assed before the chluriclc was obtained by Oerstadt by subjecting alumina to the action of jiotassium in a crucible heated over a spirit-lamp. The discovery of alumin- ium was at last made by Wbhler in 1827, who succeeded in 1S46 in obtaining nunute globules or beads of tliis metal by heating a mixture of chloride of aluiiiina and sodium. Deville afterwards con- ducted some experiments in obtaiinng this metal at the expense of Napoleon 111., who subscribed £1,500, and was rewarded by the presentation of two bars of aluminium. The ]u'ocess of manufacture w^as afterwards so simplilied that in 1857 its piice at I'aris was about two dollars an ounce. It was at first manufactured from common clay, which contains about one fourth its weight of aluminium, but in 1855 I5o.se announced to the seientilic world tliat it could be obtained from a material called "cryolite," found in Greenland in large quantitii's, imported into Ger- many under the name of "mineral .soda," and used as a washing-soda, and in the maiuifai'ture of soap. It consists of a double lluoride of alumiiuum and sodium, and only requires to be mixed with an excess of sodium, ami heated, when the 7nineral aluminium at once separates. Its' cost of manufac- ture is given in the following estimate : for one ptjund of metal, 16 llis. of cryolite at 8 cts per pound . . .? 1.28 '2\ lbs. metallic sodium at about 20 cts per lb. .70 Flux and cost of reduction . . . 2.02 $4.00 Aluminium is n.sed largely in the manufacture of cheap jewelry, by making a liard, gold-colored alloy with copper, called aliiminiuin bronze, con- sisting of 00 per cent of cojiper and 10 Jier cent of abmnniuin. Like iron, it does not amalgamate directly with mi'rcury, nor is it readily alloyed with lead, but many alloys with other metals, as co]iper, iron, gidd, etc., have been maile witli it and found to be valuable eondiinations. One ]iart of it to one hundred parts of gold gives a hard malleable alloy of a greenish-gold color, and an alloy of J iron and J aluminium does not oxidize when exposed to a moist atmosidiere. It has al.so been used to fonn a nu'tallic coating upon other metals, as copper, luass, ami German silver, by the electro-galvanic jiroeess. Copper has also been deposited, by the same jirocess, upon aluminium plates to facilitate their being rolled very thin ; for unless the metal be pure, it requires to be annealed at each passage through the rolls, and it is found that its llexibility is greatly increased by rolling. To avoid the bluish-white ap]iearance. like zinc. Dr. Steven.son JlcAdam rcc- onnuends inuuersing the article nia16-(-.0203 Ag. -^24 (Al.,-l-Cu.,) = . 9241-1-. 0570 -I-. 01 88 Ag. -1-24 (A'.,-|-Cu.,> =. 9-330 -F.0.=)n4-F. 0166 Ag.-h24 (Al.j-i-Cu.,)^ .9400 -(-.0450-1-. 0150 The three following formulas produce alloys for journal-boxes, etc. for machinery : — Cu. Al. Zn. Zn. -F2 (Al.,-!-Cu.„^ = . 8643 -F. 0622 -(-.0734 Zn. -(-2 (Al. , -I- Cu.j> = . 9053 -(-. 0435 -f .0512 Zn. -i- 2 (Al., + Cu.,.) = .9273 -(- .0333 -(- .0394 These alloys are hard and tenacious, but are ehar- acteiized by considerable shrinkage in cooling hom a molten state, the last-mentioned alloy ha\-ing considerably more shrinkage than either of the oth- ers preceding it. The said alloys have, when dra«Ti into wires of about one thirtieth of an inch in diameter, a tensile strength to the square inch of section in the preceding order of about 90,000, 103.000, and 84,000 lbs. The following alloys are adapted for gun-metal, being hard, tenacious, laminable, and ductile. Cu. Al. Fe. Fe., -I- (Al., -I- Cu.,5) = .9203 -I- .0267 -1- .0530 Fe., -(- ( Al., -(- Cu.„ ) = .9399 -(- .0446 -(- .0149 Cu. Al. Zn. Fe. Fe., + Zn., + (.U., + Cu.,.) = .SS^R -f- .0.W2 -f .0712 + .0(500 Fe., -f Zq., + (Al , + Cu.,:) = .8B61; + .024y + .0588 + .0490 The tensile strength of the above alloys when reduced to' wire, as above referred to, is for the srpiare inch of section about 82,000 lbs. for the first of the last series of formulas, 84,500 lbs. for the sec- ond, and 107,700 lbs. for the last. Where zinc or tin, or botli, enter into the alloys in place of silver, the color of the resultant alloys is somewhat atlected, and the luster is diminished. In the following alloys nickel fonns the third element of the combination of the first formula and platinum the third element of the combination of the second formula. Cu. Al. Xi. Ni. 1-1-6 (Al.,-(-Cu„) = .9129 -(-.0634 -(-.0237. Cu. Al. PL PI. H-21 (Al.,-(-Cu.„> = .9117-1-. 0656 -I-. 0225. Those alloys into which jilatinum is introduced are less aflected by acids than tho.se in which silver takes the place of I'latinum ; either the platinum or the silver gives a high luster to the alloy, platinum producing this result in a gicater degree than silver. In those .alloys in which are introduced iron or other light-colored metals, which are difficult of f-i.sion, it is preferable to bring the easily fused metals into a molten state, and then to mix those less fusible with them in the foim of shreds, parti- cles, fine wire, or thin plates. Aluminium and its alloys are combined with vul- canite in the patents of Fowler, Febniary 7 and 11, 1865. According to some analyses, wootz (East Indian steel) is alloyed with aluminium. LAXC.isTER's (1S58, England) gim-metal : copper, 90 : aluminium, 100. Al'um Leath'er. Leather tanned by a compo- sition of alum and salt. Three pounds ol salt and four of alum are used to one hundred and twenty middle-sized skins, which are placed in a tumbling- box with a sufficient quantity of water. The pi-oces.s with the succeeding operations, is described under Tawing, which see. Alum was used as a tanning agent bj- the Sara- cens. Al've-o-lar Por'ceps. A cutting-forceps or nip- pers for gnawing away inotriuling portions of the al- veolar ridge, to get a better base for a denture, or to remove points which prevent the healing of the gums. Am'a a'sa. Pieces of glass used in enameling. A-mal'gams. An amalgam is a compound of mercury with another metal or metals. It dift'ers from an alloy in posses.sing mercuiT as a constitu- ent. Compounils of other metals, with no mercury included, are alloys, whatever may be their com- parative quantities or complications. Mercury does not combine with all otlier metals, but unites with notable readiness with gold, silver, copper, zinc, tin, lead, palladium, and bismuth. It is the gieat means AMALGAMS. i'A AMALGAMS. of selecting ami aggregating by absorption particles of gold anil silver wliieb are set free by the eom- luinutioii of their niatri.\, but are so distributeil in the powder as to recpiire a congregating agent. The quart/ rock having been jiounded or ground so as to reduce it to powder, loo.sening the limi bond of the rock upon the particles of metal distributed through it, the mercury is well mixed with the dust, water being added to form a pulp. The nu'rcury insinuates itself througliout tin- mass, and absorbs the precious metals therein. Being removed from the saiul and dust of the rock, the quicksilver is set free by sublimation, leaving the non-vajiorizable metals in the retort. The (juicksilver fumes are gathered and condensed for re-use. Pliny says, " The most convenient mode of gilding copiier is to emiiloy mercury, which is applied in the form of an amalgam to the copper, to enable it to retain the gold leaf when laid thereon." They also understood the art of obtaining mercury by subli- mation of cinnabar, or by stamiiing and application of vinegar. In the process by destructive distilla- tion, the cinnabar was placed in a Hat earthen pan covered with a lid and tlien enclosed in an iron pot luted with clay. Heat being applieil, the fumes were conden.sed and collected in globules on the lid. In some cases the (piicksilver is ]nesented in the form of vapors which condense and unite with the metals to form an amalgam. Auriferous sands are subjected to the same pro- cess of amalgamation by bringing them in contact with a body of mercury. The mechanical processes are deserilvd under AM.\l,ii.\M.VTni:.s, which see. The aiqilication of an aunUgam of .sodium and mercury in extracting precious metals was invented by Wurtz of New York, and patented in the United States, June '27, 1SG5. Crookes, of England, subse- quently to the date of Wurtz's application for Uniteil States patent, maile apiilication for a patent in England for the sauv invention. The extraction of the ]irecious metals by amal- gamation has hitherto been much impeded and its cost increased by the presence in the ores of com- pounds of suliiluir, arsenic, antimony, bisnuith, or tellurium, which, by covering the gold with a thin film of tarnish, prevent its entering into combina- tion with the mercury. The use of .sodium amal- gam, under these circumstances, ii to prevent the "sickening" and "flouring" of mercury which the presence of these compounds, and especially of sul- phate of iron, is so apt to jn'oduce. The olii'ial statement of Wurtz's invention is as follows : This invention consists in adding to quick- silver, to be used in the amalgamation of gold, silver, etc., a small cpiantity of an amalgam of mercury and sodium, or other equivalent metal, as potas- sium ; by this addition the mercury nmre readily attacks the precious metals. Menaiiy treated in this way will also form a mercurial film or coat- ing on iron or steel, so as to form amalganuited surfaces, to take the place of the usual ciq)per plates. The mercury so treated is less liable to " fiour." Claim. — First, the combination with (piick- silver, when used tor the extraction by amalgama- tion of metals from their ores or their mixtures with other materials, of metallic sodium or metallic, potas- sium, or any other highly electro-positive metal . eipiivalent in its action thereto, as above set forth. Second, in those amalgamations in which amalga- mate. 1 plates of co])per or other metal are used, the suUstitution for the plates of cop]ier or other metal of iron coated witli quicksilver combined with sodium or othi'r highly electro- positive metal, as abovc^ set forth. Third, the coating of iron, steel, or other metallic surfaces between or under which ores or other mate- rials are crushed, with ([uicksilver combined with sodium or other highly electro-positive metal, as above set forth. Fourth, the prevention of the granulation or flouring of ([uicksilver when used in any method of amalgamating ores or other materials by addition thereto of sodium or other highly electro-positive metal, as abo\'e set forth. The valuable woik of Phillips on mining gives the com]ii'ndium following : A ([uantity of sodium amalgam dissolved in a hundred times or more its weiglit of (juicksilver is saiil to comnmnicate to the wdiole a gi'eatly enhanced power of adhering to metals, and jiarticularly to those which, like gold and silver, are situated toward the negative extrem- ity of the electro-chemical scale. This power of adhesion in the case of the two metals is so great that the resistance which their snrfaces, when in their native state, often oppose to amalgann^tion (a resistance much greater, and nmre general than has been hitherto recognized, and due to causes as yet uninvestigated) is in.stantly overcome, whether their particles be coarse or inqialpable. Even an arti- ficial coating of oil or giease, which is usually such an enemy to the combination of mercury with other metals, t'oiins no obstacle to innncdiate amalgama- tion by this prepared ipiicksilver. The atoms of quicksilver are, as it is described, put into a sort of polaric coiulition by a minute addition of one of the metals which range themselves toward the electio-]iositive end of the .scale ; so that its aflinity for the more electro-negative metals is stated to be so greatly exalted that it seizes upon and is instan- taneously absorbed by their surfaces, just as water is absorbed by a lump of sugar, or other porous sub- stance .soluble in it. Such quicksilver even adheres strongly to snrfaces of iron, steel, ])Iatinum, aluminium, and antinmny ; an adhesion which, however, in the case of these metals, is not a true amalgamation, there being no ])enetiation into the substance of the metal ; so that the snperlieially adherent quicksilver may be readily wiped oil', just as water may be renmved from glass. The only metal as yet experimented on, which can- not be enfilmed by the use of sodium amalgam, appears to be magnesium. Application of Sndium Amah/am to IVorking Ores of the Precious Metals. This consists in adding from time to time, to the quicksilver used in amalganuition, about one hun- dredth jiart of its weight of sodium amalgam. The frequency with which the amalgam is to lie added cannot be exactly specified, as it will be found to depend on a multitude of circumstances, — such, for instance, ;\s the temjieratui'e, the purity ami quan- tity of the water used, the ratio borne by the sur- face of the quicksilver to its mass, the amount and mode of agitation of the quicksilver, the nature of the process and apjiaratus used, the character of the ore; strength of the amalgam, etc. ; so that this important point can only be determined in each case by experience Some general indications may, however, be derived from the experiments which have been made. It is said that less sodium is reipiisite in eases in which nuich water is enqdoyed, and whim the water is IVeqiUMitly renewed, — as, for instance, in the riffles of a sluice, and in all forms of amalgamators through which a continual current of water is kejit running, — since mercurial solutions of sodium are but little affected by water free from acid, alkaline, or saline imjnirities. In cases, however, in which but little water is AMALGAJI8. AMALGAMS. employed, and especially where the ore and quick- silver are ground togetiier into a slime, the water soon becomes alkaline, and oxidation of the sodium sets in, necessitating its frequent renewal. In such cases the following manipulation is rec- ommended. The whole amount of quicksilver to he used for working up a batch of slimes, say fifty pounds, is prepared by dissolving in it one per cent of amalgam No. 2, or better, two per cent of the soft amalgam No. 1, which dissolves more readily ; one half, or twenty-tive jiounds, is then thrown into the mill with the ore, and, as the incorjioration pro- ceeds, certain fractional parts of the other lialf are added at intervals, varpng according to circum- stances, until the whole has been introduced. If, as is usual, the quicksilver has been separated from the slimes of a previous operation, it will retain a certain amount of sodium, and therefore require fresh amalgam in proportionately smaller quantities. No. 1 amalgam contains two per cent and No. 2 four per cent of sodium ; the latter is a hard, brittle solid, remarkably infusible, reiiuiring a tem- perature nearly as high as the fusing-point of type- metal to melt it, and may be cast into ingots, and packed either under petroleum, or in air-tight iron cans filled with dry lime. In sluicing operations, the soft amalgam No. 1 is, on account of its ready solubility in mercury, most recommended ; and in these cases it is practicable to test the quicksilver in the riffles, and ascertain when the magnetic quality reciuires restoration, by throwing in a few grains of gold-dust. Similar tests are easily applied to slimes, and in amalga- mating generally, a slip of tarnished sheet-eopper is a suitable agent for such testings. It may be remarked that the amalgam No. 1 is at any time easily prepared from No. 2, b\' melting it in an iron ladle with its own weight of quicksilver. In copper-plate amalgamation — that is, in cases in which auriferous materials are brought into contact with amalgamated metallic surfaces — it is recom- mended to substitute for quicksilver itself the pasty amalgam No. 2. In these modes of amalgamation gi-eat economy in wear and tear of apparatus, as well as in first cost, is said to be etfected by using jilates or sur- faces of iron instead of copper. The power of coat- ing or enfilming iron is stated to render these amal- gams peculiarly valuable in every form of apparatus for amalgamation which has internal surfaces of iron ; for these, becoming coated with quicksilver, immensely extend its chances of contact with parti- cles of gold, so fine as to remain suspended in the water. Otlier important services are ex])eeted by the inventoi-s to arise out of this power of enfilming iron, such as keeping the surfaces of stamps and of other apparatus used in crushing ores continu- ally coated. In like manner, as the power of adhe- sion of quicksilver to other metals is exalted by the presence of the alkali-metals, so also is its own cohesion stated to be greatly increased. It is rendered more difficult to mechanically divide, afid when thus di«ded again runs instantly together upon contact. Hence new results of great value are said to have been obtained. For instance, the so-called "flouring" or granulation of iiuicksilver, which in the amalgamation of ores always occasions losses both of the (juicksilver itself and of its amal- gams with the pirecious metals, is stated to be reduced to a minimum, or altogether ]irevented. The recovery of "floured" rjuiiksilver and amal- gams from slimes and similar mixtures is also said to be greatly facilitated and accelerated thereby. For this purpose some sodimu amalgam is thrown into ^ the separator, and collects and incorporates all the scattered globules of auriferous amalgam. It is here necessary to call attention to a method of manipulation generally applicable when sodium amalgams are used, and particularly so in all cases in which the ore is ground or agitated with quick- silver in contact with metallic iron. This arises from the liability of abraded particles of iron to adhere to the amalgam. The following plan is, therefore, in such cases recommended. The amalgam, after separation from excess of quicksilver, and before retorting, is fused in an earthen dish or ii'on ladle, with, if necessary, the addition of a little quicksilver to make it more liquid ; and the iron, which forms a scum on the suiface, is skimmed ofl'. The excess of quicksilver may, after cooling, be again separated from the amalgam in the usual way. Any amalgam which adheres to the iron scum is readily detached by boiling in water to remove the sodium. This pro- cess depends on the fact that adhesion to the iron totally disappears with the extraction of the last traces of sodium from the quicksilver. It is, in fact, possible to remove all iron from the amalgam by boiling in water without any j)revious fusion, jiarticularly if the water be made somewhat acid or alkaline. The presence of iron can be readily de- tected by the magnet, which may also be sometimes used with advantage in separating iron from amal- gam after all the sodium has been extracted. There are still other substances which may be found adhe- rent to the amalgam when sodium has been used, such as platinum, or osmiridium, or both, with iron, and these may be freed from the latter by tlie magnet. The sodium amalgams prepared in accordance with the recipes of Mr. Crookes are known respec- tively as A, B, and C amalgams. Each of these contains three per cent of sodium, in addition to which B has a small quantity of zinc in its composition, and C a little tin. An amalgam (A), of seven times the strength of the above, is prepared in solid bars for shiimient when the ex- pense of freight or land caniage is great. Amal- gams /> and C cannot be prejiared in the concen- trated form. It is recommended that one part by weight of amalgam B or C be dis.solved in thirty • parts of the mercuiy which is to be used in the amalgamating, triturating, or giindjng machines, and the efl'ect which it produces on the mercury noted from time to time during the operation. If it retain its fluidity and brightness to the end of the operation, it is a .sign either that a sufficient amount or too much has been added, and a second experiment shoxdd be trieil with a less quantity of amalgam. But if it be "floured," or "sickened," or any loss occur, more amalgam may be added until the best proportion is arrived at. Mr. Crookes states that amalgam B will generally be found etfective, but if the ore contain an excess of any mineral which has a deleterious action on mer- cury, more especially if it contain bismuth, it will be advantageous to employ amalgam (.' instead of B. When the best proportion of amalgam B or C is determined, small quantities of amalgam A should be introduced into the mercury, already containing amalgam B or C, in the proportion of one part of amalgam A to one thousand of mercury. This quantity of amalgam A can be added every few hours, according to circumstances, but one charge of amalgam B or C will, it is stated, u.sually be suf- ficient for several days. Under some circumstances it will be found advisable to add amalgam B or C every few days, but a little experience and com- parison with the results obtained by the old :.Ian AMALGAMATING ZINC PLATES. 74 AMALGAMATOR. will soon show how these several agents are best utilized. The process of extraction of the precious metals by the leml-bath will be found under Le.\I)-1!ATII FOR THE EXTKACTION OF Ool.I) AND SlLVKIl. Other processes for gathering gold (excepting A.MAi.cAMATOus, wlucli See) lire included under tlie general title Gold-wash Kii. The ore-crushers are described under Ore-stamps, etc.; Ore-ckixdi.sc. Mills; Arrastk.\s. An amalgam of mercury and tin is used to coat the liack of looking-glasses and glass mirrors. This amalgam consists of mercury, 3 ; tin, 1. It is foi'uied by laying a sheet of tin-foil on a table, covm'iug it with mercury, and then, by a sliding movement, placing the sheet of glass over it. An amalgam of gold is also used by jewelers to overlay other metals by a fine tilm of gold, after which the mercury is driven olf by heat. In Mallet's ]irocess (English) for preserving iron from rust and ship's sheatliing from fouling, the iron is dipped in an amalgam of zinc, sodium, and mercury. The process is as follows : — The jdates are cleansed in a warm solution of equal [larts of acid (sulphuric or hydrochloric) and water. The scale anil o.\ide are removed from the metal by scouring. The plate is then placeil in a prcpnriiifi-hiith consisting of a saturated solution of hydroehlorate of zinc anil sulphate of auuuuuia. It is then immersed in a bath formed of Mercury . Zinc . 20-2 1,292 To each 2,240 jiounds of which amalgam 1 pound of potassium or sodium is added. ■The iron is sjieedily heated, and is withdrawn before it reaches fit<0' Fall., at which temperature it would be soon dissolved by the alloy. A similar process, so far as the manipulation is concerned, is |ia.s.sed through in the palladiumizing jn'ocess, in which, after cleansing, the plates are inmiersed iu a fused amalgam of palladium and mercury. Amalgam for the electrical machine : — Zinc 2 Tin 1 Mercury ..... 4 Melted in tlie oi-der named, in an iron spoon. Shake the fused amalgam till cold, triturate in a mortar; sift; rub up the powder witli lard, and ajiply with a palctti--knife to the rubber of the macliine. Amalgam for silvering the iusides of hollow glass spheres : — Mercury 3 Lead 1 Bismuth 1 A-mal'ga-mi'ting Zinc Plates. Zinc plates for th ■ vultait' battery are amalgamated with mercury, so tliat no action of tlie .snipiiuric acid takes place Oil the zinc when the circuit is not closed. To amalgamate the plates, tlievare first pickled in ddute .vulplmiic acid (acid 1, watc'r S) in a stone- ware pan. A little mercury, heiiii; juiured into the pan, is rubbed on both sides of the jilate by means of a swal). The plate is wa.slicd in clean' water, Jilaeeil on its edge to drain, again rulihed with, mercury and drained. Another ;ni'tliod is to cli.;iu the plates with emery, pickle, and wa.sh. Then dip the clean plates iu'a im.\ture of ecjual parts by weight of bichloride of ' mercury (corrosive sublimate) and acetate of lead. I Hull with a (doth, and they are ready for use. A-malga-ma'tor. It appears from Pliny, A.D. 79, that tie' ancients were acquainted with amal- i gams, in their uses for separating gold and silver from earthy particles, and iu gilding. Pliny .says : "Mercury is an excellent refiner of gold, for on being shaken in an earthen vessel with gold, it rejects all the impurities that are mixed with it. When once it has thus expelled these iin]nirities, there is nothing to do but to separate it from the gold ; to effect which it is poured u]ion leather, and exudes through it in a sort of perspira- tion, leaving the jiure gold behind." Vitruvius (B. C. 27) describes the manner of recovering gold from cloth in which it has been interwoven. The cloth, he says, is to be ]nit in an earthen vessel, and ]ilaced over the fire in order that it may be burnt. The ashes are thrown into water, and quick-silver added to them. The latter unites with the particles of gold, the water is poured off, and the residue put into a cloth, which being sciueezed with .the hands, the quicksilver, on ac- count of its Ihiidity, oozes through the pores, and the gold is left pure in a compressed mass. It is commonly stated that the ancients did not under- stand the art of recovering mercury by retort and receiver, but a description of the apparatus by Pliny (see Amalgams) contradicts this. It does not, however, seem to have been much practised. In the year 1582, Herberer described the washing of gold as he saw it practised at Selz, not far from Strasburg, and at that time quicksilver had long been used for that purjiose. The cinnabar mines of Pera were discovered about 15tJ6 by Garees, wlio observed the Indians using a native red earth for paint. It does not a|ipcar to have come into general u.se in the silver- mines of Peru, as a means of e.xtracting the silver from the earthy particles, till 1571, when Pero Fernandas de Velasco came to Pern and offered to refine the silver by mercury, as he had seen in the .smeltingdionses in Mexico. His pro]iosals were ae- cepteil, the old methods abandoned, and that of amal- gamation pursued as it is juactised at jnesent. In 1572, Hawks writes that "an owner of a mine must have much quicksilver, anil as for this charge of ([uicksilvcr, it is a new invention, which they find more profitable than to fine their ore with Icad."- Ilidhiyt's 1 'mjaijcs. The number of patents granted in the United States for amalgamators cannot be readily .stated, as so many of the cru.shers, grinders, and arrastras become amalgamators by the addition of mercury. To state the whole nnniber would give an exag- gerated view, as many of them are merely mechanical grinders without any specific adaptation to the re- quirements of theniercurial process. The number of patents for amalgamators in the Uniteil States may be ai)]iroxiniately stated at two hundred and sixty, January, 1872. '\\ ith the exception of the aKrentiferous galena, .silver is generally found in the form of brittle sul- jihides disseminated through the gangue or veip. .stone. The.se particles, in the o)ieiatiou of grinding or stam)iing, are reduced to a fine jiowder, which lloats olf in water in the jiroce.ss of concentration. It becomes necessarv, therefore, to a]iply a gathering agent which will collect them, and the notable activity of ipiicksilver in entering into combination with the precious metals has cau.sed its selection as the desired agent. The subject is .-ipecially treated under Amalgams, and the mechanical processes and manipulation are the subject of this article. AMALGAMATOR. 7.5 AMALGAMATOR. The processes and macliines for the amalgamation of silver are various, and arc : — The Patio process. The BaiTel process. The Hot process. The Fan process. The Estula process. These will be separately considered. Siicceedinc; the description liides are not reduced by tliis pro- cess, and are therefore added to the material of the patio, but do not require the addition of magis- tral, as they contain a sufficient amount of chloride of copper to convert the sulphides of silver into chloride ; the copper is furnished by the attrition of the bottom of the vessel, which is kept clean, by the paddle in the case of the "cazo," and the cop- per block in the case of the "fondou." The prop- er proportion of the mercury and the mechanical action prevent the loss of mercury by adherence to the bottom of the pan. The EsTfFA Process. In some of the colder and more humid districts of Mexico, a modification of tlie patio process has been employed. The ground ore, instead of being exposed in the open air on a paved courtyard, as in the ordinary patio process, is placed under a shed, and the usual method of patio amalgamation proceeded with, until the operation is about half completed. The ore is then removed into a chamber tefmed an exfiifn (stove), which has under it a fireplace six or eight feet long, so con- nected by side flues with small chimneys as to elevate the temperature of the room containing the ore. Here it is exposed to a gentle heat, and al- lowed to remain during two or three days, when it is again removed, and the reduction completed by the ordinary method of patio amalgamation. By this process, the time required for the reduc- tion of the ore is less than by the patio, and the yield of silver greater ; the loss of mercury, ou the other hand, is more considerable. The B.\uuEL Process. An apparatus of this de- scription was in use at the latter part of the last century in Germany. It is described as "an apparatus consisting of eighteen small, cylindrical, by pinions upon their shafts engaged by the teeth of a large spnr-wheel. Each cask had a circular apei'ture, closed by a lid while revolving, and opened a,s required to receive a charge of roasted ore by a spout from the hopper above ; or openeil, when in the reverse position, to discharge its contents into the hopper below, after the argentiferous mer- Fig. 143. Freiberg Ama/gamaiur (vertiral section). vertical vessels, arranged in a circle, in which the ores were mLxed with niercurj' and constantly agi- tated by a vertical spindle in each tub, the spindles being worked by a large, horizontal spur-wheel placed in the center." The amalgamating apparatus of Freiberg con- sisted of wooden casks arranged in rows and driven Freiberg Amalgamating Barrels {.top fine). cury had been withdrawn at another opening, which at other times is closed by a plug. Each barrel is charged with 300 pounds of water and 1,000 ])Ounds of finely gi'ound ore ; fragments of iron arc added, the barrels closed and set in motion. When the material is i-educed to a paste of the proper consist- ence, 500 pounds of mercury are added to each cask, and the closed barrels revolved for 16 hours at the uniform rate of 13 revolutions per minute. By the addition of water and subsequent revolution at a slower rate, the mercury is separated from the slimes and collects in a mass below the water, which holds the major part of the earthy particles in sus- pension, by the aid of moderate agitation. The mercury is then withdrawn by removing a plug and conducting the metal by a hose to a spout and receiver. The passage of earthy particles indicates the time to stop the flow. The plug is replaced, the lid withdrawn, and the muddy residuum dis- charged into troughs below. The cldoride of silver contained in the roasted ores is, as in the Freiberg process, decomjiosed by agitation with iron frag- ments, the chloride combining with it to form protochloride of iron, while the reduced' nu'tallic silver becomes subsequently dissolved in mercury. The ehiorides of lead and co])per which may be present are reduced at the same time as the cldoride of silver, and enter into the composition of the amalgam produced. The cldorides in the roasted ores are, by trituration with iron, reduced to the state of minimum chloi'ination, before the addition of the mercury, allowing the latter to act ujion the silver immediately, and obviating the conversion of the mercury into calomel, which would not be again reduced and would prove a loss. The muddy residuum, previously referred to, is re-treated, if sufficiently rich, by roasting, etc. Tlie amalgam obtained is filtered in tlie usual manner, and the remainder distilled to sublime the mereuiy. The metallic result is then refined. The barrel puocess at the Ophir and other mines in Nevada is preceded by drying the ores in a kiln ; dry stamping, screening through wire sieves, and roasting in reverberatory furnaces for from 4J to 6 hours. About 5A per cent of salt is added by portions in the furnace, the ore being stirred, and, before drawing, li to 8 per cent of carbonate of soda is added to decompose the sulphates and chlorides of copper, zinc, etc., and prevent loss of quicksilver. The roasted ore is then screened and the barrels AMALGAMATOR. 78 AMALGAMATOR. are cliaigi'd with it. The charge of eacli harrcl is 2,000 poiiiuls of ore, 4.50 jiomuls of iron fra^'nifiits, anil water sulHuit-nt ; tliuy arn then revolveil for 3 liour.s. From 350 to 400 pounds of niercuiy arc now adilfd to cac-li barrel, which are then revolved for 12 or 13 hours at the lute of 12 revolutions jier minute. They are then filled up with water, a<,'ain run fi>r 2 liuurs, and tlic water drawn otl'. The amali;ani is strained tinouyh a canvas bag to remove a portion of tlie nuicksilver. The tailings are washed in a settler, and thence passed through a series of sluiee-bo.xes into a Hume about (iUO feet long and 4 feet wide, pi'ovided with riffles. The amalgam is distilled in circular retorts. The I'.VN rudCKss. • This process was dc-signed especially for operating ujion ores of poorer cpiality, dispensing with roasting incident to the barrel pro- cess and to the frei[uent manipulations and loss of time incident to the patio process. The ores of the mine being sorted into three grades of comparative richness, tlie first, assaying over $ 90 per ton, and containing a great deal of sulphur and refractory metals, is stamped dry and reserved for the barrel process; while the second, from 1 40 to $90 per ton, and the thinl, from | 20 to S 40 per ton, are stamped wet and treated by the pan process. Tlie cruslunl ore, after pas.sing through the screen of the stamp-box, is conveyed to the settlers, passing from one to anotlier till the water runs off clear. The ]ians are very various in their construction, and a number of tliem will be shown in this section of the article on amalgamation. The connnon pan is a round, wooden, or east-iion tub, six feet in di- ameter, two feet in depth, and with a Hat bottom. Fig. 144. the apertures J. The false bottom is made one inch less in diameter than the bottom of the pan itself, and has an aperture in the center an inch lai-ger in diameter tlian tlie base of the pillar, in which the vertical shaft works. To fasten the bottom in its Fig. 145. Commi'n Amaf^fimntitjg Fan. A false bottom of l.\-inch iron is iirserted into this, and a Indhiw pillar in the center admits the pas.sage of an upriglit sliaft whicdi is generally worked by gearing beiieatli tile pan, capable of communi- cating to it from lifteen to twenty revolutions per minute. It is sometimes geared mucli higher. To the wooden arms a are attached the blocks b, also of wood, to which are fastened the iron shoes c, by means of the bolts d, passing up through the arms. Each slioe has also an iron pin, about an inch in length, which fits into the wooden block and keeps the iron -facing steadily in its place. On the shaft / passing through the central pillar r is the yoke (j, which, being fitted with a sliding key, can be raised by m"ans of the screw /( ,- and the endsof the yoke itself, being attaclied to the wooden cross-arms, the mul'ers will be raised at tlie same time. Steam is introduieil into the pan by the jiipe i, the discharge being clfected by means ot Norlands Amalgamator. place, and jirevent the mercury from finding its way under it, strips of cloth, abc-.;t two inches in width, are lapped around the edge of the false bottom, as well as applied against the sides of the pan. A little iron cement is then poured in, and the bottom secured in its place by means of well-dried wooden wedges tight'y driven between tlie two layers of cloth. These wedges, which are driven quite close to each other, must be somewhat shorter than the thickness of the false bottom, thus leaving a space above them which is subsequently covered with a paste of iron cement, that is allowed to set before using the apparatus. About one- horse power is required to work this pan, which will amalgamate from one and a half to two tons of on^ in the course of twenty-four hours. NdHTON, September 18, 1860. The annular re- volving funnel G di.stributes the powdered material by pipes // to the space near the central pillar through which the vertical shaft passes. The grooves in the faces of the muUer and bed-plate are arranged in curved lines, so that the material is fed from the center towards the circumference before it reaches the discharge-openings 0. Projecting points, as the mnller and bed-plates, act upon the fed material, and force it from the center as it passes from the pipes If into the mill, giving it an eccentric motion, and causing it to come repeatedly under the tiiturating operation. The balauce-rynd with its niullers is adjustable vertically on the shaft to regulate the proximity of the grinding surfaces. Vaiiney, December 16, 1862, and July 12, 1864. AMALGAMATOR. 79 AMALGAMATOR. A stationary bed-plate is attached to the floor of | balance-rynd a, to wliose ends are attached the mul- the pan A, and has radial grooves which are tilled with wood. The rotary-disk lias radial, o]ien grooves, formed by the intervals between the sectional pieces which are attached to tlie face of the disk and form the mullers. The disk itself is an annulus, and is connected by arms i with the outer tube /t, which forms the balance-rynd and rests ujjon the central pillar m, being rotated by the central shaft wliich is driTen by gearing below. The opening in the Vamey''s Amalgamating Pan. center of the rotating disk is considerably larger than the tube h, so as to leave a hiatus in winch the material collects. The action is such that the ore will pass outward from this central space be- tween the faces of the upper and lower mvillers, and arriving at the peripheral opening is drawn in by spiral scrapers 6-, which are supi)orted from al:iove and return the pulp over the top of the upper muller, to the central space, for a repetition of the operation. The shoes are renewable, and are secured to the disk by rivets which are cast in them. The operation of this apparatus is as follows : The space about the periphery of the lower muller is filled with <[uick- silver, and the pan nearly filled with pulp of the proper consistency to flow easily ; the shaft is now made to revolve at a proper speed, from sixty to eighty revolutions per minute, by which the upper muller is rotated. The pulji between the nnillers, by means of the centrifugal force developed, is made to pass out through the radial channels between the dies, as well as between the grinding surfaces of the upper and lower mullers ; also into and over the quicksilver, thereby causing amalgamation. The outward motion of the pulp has the effect of keeping the quicksUver entirely away from the grinding surface, thereby obviating what has often proved a very serious difficulty, namely, the grinding of the mercury. The rotation of the upper muller causes the pulp in the ))an to revolve with it. This current is met by the cuneiform projections and curved plates, and thereby turned toward the central opening in the upper muller. The radial slots between the shoes, running from the central opening to the outward one, allow currents of considerable size to pass with great velocity ; and the pulp filling these .slots, being continually thrown outwardly, tends to pro- duce a vacuum. By this the pulp in the body of the pan is set in motion, causing a rapid and abun- dant flow downward at the center, and upward along the inner surface of the pan. The pulp is thus made to circulate until the complete pulver- ization of the quartz and amalgamation of the metals have taken place. CoLEMAX, August 18, 1863. The muller of this pan is driven, as are the preceding, by the central vertical shaft which is jirojected up the central cavity of the annular pan. The shaft supports a ler C, which revolves between two plates B D, re- spectively below anil above. The muller C has cor- rugations on its upper and lower surfaces, as have also CotemafCs Amalsamator. the surfaces with which it comes in contact. The vertical position of the rotary-wheel or muller is ad- justed by the central wheel b, and that of the upper plate H by the set screws c, which are four in num- ber and set at opposite points. By this double ad- justment the spaces between the grinding suifaces are gradually ajiproached, as the pulp becomes finer in the progress of the work. Wheeler, December 8, 1863. The lower face of the rotary-muUer has spirally cuivcd grooves which act in apposition to reversedly curved spiral grooves on the bed-plate or stationary muller. I'ig. 148 is a vertical section, and Fig. 149 shows the pan in perspective, the muller being raised and turned bot- tom upwards. The dies a are attached to the bed Fig. 148. Wheeler's Amalgamating Pan. of the pan, and the shoes b to the rotary-disk ; this is attached to the hollow cone F (see Fig. 148). which is connected to the vertical shaft ff,_ and that to gearing beneath the ]ian. The dies a are kept in their places by the central ring e. and on the sides by the inclined ledges d, under which their edfes are wedged. Spiral ribs are fi.xed on the periphery of the rotary-muller, and act in concert with revei-sedly spiral ribs d attached to the side of the pan to create an u]nvard current in the pulp, which is then swept toward the center again by curved guide-plates attached to the blocks c on the AMALGAMATOR. 80 AMALGAMATOR. Fig. 149. Wheeler^s Amalgamator. inside of tlie pan. Tliis pan is i feet in diameter at the bottom, is said to renuire from 2i to 3 horse power to run it etfeetively, and is geared for sixty revolutions per minute. Tlie muller is connected to its driver liy a universal joint. The pan has a double bottom, ancl is heated by steam admitted to the space thus tormcd. WilF.i;i.EU, July 14, 18(53. This machine is con- structed for saving the mercury from the pulj) or Fig. 150. Wheeter\t Separator. waste matter which escapes from the ordinary amal- gamators, and consists of a tub with concave bottom and a central depression, in which is a vertical tubu- lar rotary-shaft having arms on which pads are placed, wliich rub on the bottom and collect the I)articles of mercury which run down into the cen- tral chaTubt-r ; water is suiiplied tliroui^h the hollow shaft, which may be decanted olf by a siphon or cocks, and the quicksilver drawn olf by the lower tube connected witb the gatheiing-chaniber. Ilr.i'iuii'.x Asn PF.TF.itsoN, April 19, 1S64. This ])an dill'ers mainly from the foregoing in the shape of tlie bottom, which is inclined towards the center, or shaped like an inverted cone. The shoes are bolted to the face of the conical muller in such a Fig. 151. Anial£;amnting Pan- way as to leave intervals which form spiral grooves. Tlie dies of the bed are fastened to the pan bottom, and have a similar aiTangement. forming spiral con- ductors whereby the )inl)) is led towards the periph- ery ; ascending against the sides of the ]ian, it de- scends by gravitation over the upper surface of the rotary-mnller, is collected at the center, and again driven outwards. A constant and active circulation is thus established without the aid of the curved scrapers shown in some of the ]jrec<'ding examples. The cbai'ge for this ]iaii is about 1,400 ]iounds, and the time requisite for working it from two to four hours, according to circiuiistances. The rate of run- ning is from fiity to sixty revolutions jier minute. The muller is sujqiorted upon a balance-rynd, as in the previous e.Namjiles, and is adjustable veitically by hand-wheels, a thimble, and a' tubular screw. The following two are examples of planetary mo- tion. Hansbkow, October 27, 1863. The pan has the Fig. 152. Hansbrow^s Amalgamating Pan. AMALGAMATOR. 81 AMALGAMATOR. same fcntuies as the foregoing, but the action of the muUers is different. The vertical shaft is driven by gearing beluw, and passes up through a central cavit}- in the annular pan. On the summit of the shaft is an arm iu which are journaled the vertical shafts of the dependent muUers. Each of the latter shafts has a pinion which engages a circular station- ary rack on the inner edge of the pan, so that, as the mullers revolve around the main .shaft, they have also a rotary motion on their own a.\es. They thus acquire what is called a planetary motion, ro- tating as they revolve. The grinding effect of this motion is very satis- factory, and the uiuUers wear nearly evenly. The effect of a simply revolving niuller is to wear the fastest nearer the periphery, as that passes over a gi'eater frictional surface in describing a larger cir- cle. This difficulty is, however, met by Dodge's patent, described elsewhere in this article. Kenvox, July 19, 1S64. This, like the one im- mediately preceding, consists of a circular pan, through the center of which passes a vertical shaft. To the upper end of the shaft is attached a cross- head fitted with a yoke, through which a screw passes and rests upon the end of the shaft. At the ends of the cross-head, bows are attached carrj'ing the vertical shalts, upon which are pinions gearing into a stationary wheel. At the end of each shaft are placed anns, and at their ends are irons for receiving the mullers. The mullers have a quad- rangu.'ar arrangement at the ends of arms o, .sim- ilarly disposed and radiating from the shafts I. As in the preceding example, they have rotation on their own axes by the engagement of their respective pinions m with the stationary wheel n, Fig. 153. and have also a revolution in the track foi-med by the annular pan, owing to the rotation of the shaft n and cross-head. The adjustment of press- ure of the niullei-s on the face of the pan is ob- tained by the set-screw ), which passes through the yoke h and rests on the shaft a. Each muUer receives a cycloidal movement. The process of working in pans is not merehi a mechanical trituration of the material, and an exposure of it to the contact of mercury. These, of course, are necessari- incidents, but the chemical reactions of the constituents are in many respects similar to those described under the patio process and the barrel process of Freiburg and Nevada. The energy of the treatment, however, has the effect of expediting the decomposition of the material and the combination of the precious metals with the mercury. S In operating, the charge ha\-ing been placed iu the pan, the muller is put in motion, and gradually lowered as the material becomes pulverized. Steam is then injected into the mass, raising its tempera- ture to 200° Fahr., care being taken to retain a projjcr consistence. The muller being slightly raised, quick- silver is added in a shower from a canvas bag, to the extent of from ten to fifteen per cent of the material under treatment ; sulphate of copper and sulphuric acid are also added in small quantities ; also salt in some cases. Many suggestions of ma- terials to be added are rife among the miners, but appear to be empiric in their character, and not derived from critical chemical consideration of the reactions taking ]ilace or required. The runnhig of the pan to complete the amalgamation is con- tinued for three or four hours. The pulp is then thinned so as to flow out of an opening in the bottom of the pan, and is conducted to the se])a- rator ; or it may be thinned and .settled in the pan, reducing the pulp so as to allow the heavier ]ior- tions to settle, and decanting the mere liquid either by siphon or by opening the cocks on the side of the pan, beginning at the uppermost and proceeding downwards in order, as the condition of the settling renders advisable. Several of the examples show these cocks, but others are so arranged that the pan will tip on its hinges and discharge its contents. In the larger pans, where it is desired to make the work as continuous as may be, the whole charge of the pan is drained oft' and subjected in a separator to a second process of dividing the eaithy paiticles from the metal, in order that the jian may be expeditiously recharged and proceed with its work. One of these sejiaratoi-s is shown in this article, but the common pan (also shown) is frequently used. In the separator the pulp is mixed with a large quantity of water, and a regular steady supply kept up, so as to carry off the lighter particles of earthy matter, at first from holes in the u]iper part of the pan ; but as the separation proceeds the discharging- point is gradually lowered, until eventually nothing but the heavier pyrites and liquid amalgam is left. The amalgam is drawn ofl'from the bottom, and the pyrites then scooped out, and after being further washed in another separating-pan, to remove the last traces of amalgam, it is reserved for final treat- ment by calcination and reduction in barrels. The amalgam is now carefully washed in clean water, ilried with flannels, and finally removed to tlie amalgam-room, where it is strained through thick conical bags of canvas twelve inches in diameter at the larger end, and two feet in length. After the bags have drained for some time, they are beaten with a round stick to cause a fcrther quantity of the mercury to I'un oH'. The haid, dry amalgam is finally removed from the bags and weighed into store. The mercury run off from the bags is technically known as "charged quicksilver," and after being mixed with retorted mercury is returned to the pan-room for farther use. Charged quicksilver is preferred to the pure metal, as with it amalgan;ation is found to proceed more rapidly. A.M.iLOAM.iTiON OF Ro.i.sTED Ores. In some of the mining districts of Nevada, and particularly in the neighborhood of Austin, where the ores con- sist of various compound sulphides of silver, contain- ing a considerable amount of antimony, the ordinary pan process, as practised at Virginia City, cannot be advantageously employed. The ores from this jiart of the State consequently require roasting before being subjected to amalgamation, and then, when AMALGAMATOR. 82 AMALGAMATOR. r 1 , T 1 woi'ki'il ill tlie p.iiis, airoid better results than tliose obtiiiiu'd tVuiii tile ores of the Coinstock vein treated in their rasv state. Each battery of five stam))ers will crush (dry) lour tons of ore daily, through a wire-gauze screen of forty holes per linear inch. One thousand pounds of this crushed ore are roasted with eight per cent of common salt ; the time occupied in tlie furnace by each charge being, on an average, si.x hours. Pans are most commonly employed, and are charged with from eight hundred to one thousand pounds Fin. 154. of roasted ore, which occupiies live hours in working. A mill often stampers, with all the necessary furnaces, pans, and appliances, willtre.at eight tons of ore in the course of twen- ty-four hours, with a total consumption of about ten cords of wood. It is stat- ed that the loss of silver in the neigh- borhood of Austin, where tlie ores con- tain little or no gold, seldom ex- ceeds seven per cent of the assay value. Si'KNCEH, Novem- Spencer^s Amalgamator. ber 22, 186-t. The treatment is designed to desul- liliurize the ore simultaneously with its exposure to tlie mercurial fumes. The ore, liiiely pulverized, is placed in a vcssl'I with a small amount of mercury, and the vessel then strongly closed. Heat is then Fig. 155. Aina'ijmn Retort. applied, so as to vaporize the mercury. After this treatment the ore is placed in any suitalile ainalga- uiating vessel, and washed and treated in the usual way. Rktokting. The silver or gold amalgam is treated in the assay-office, and the mercury separated by dis- tillation in a cast-iron retort with a luted cover, jilaced upon an arch of fire-brick, and having another arch above it, being, with the exception of one end, enclosed within a chamber. Fig. 155 shows the arrangement of the retort and chamber. Tlie charge of amalgam is weighed and placed in a semicircular tray divided by a transverse partition. Before being put in the tray the amalgam is coated with milk of lime or a thin wash of clay, a sheet of paper being sometimes placed under it ; by these means the amalgam is prevented from adhering to the tray. The tray being placed in the retort, the cover is closed and carefully luted with a thin paste of clay and wood-ashes. The fire is then lighted in the furnace, and the heat very gradually raised until the retort is at a bright red heat. The llame and smoke from the furnace pass through the Hues a a, etc., up into the chamber b and around the retort, tlie smoke, etc. ascending into the chim- ney d through the flues 1, 2, 3, etc., and the cham- ber c, the draft being regulated by dampers at- tached to these flues. A horizontal pipe Z> is fitted into the inner end of the retort, and is so connected to the vertical downcast pipe E that they admit of being readily separated for cleaning ; the pipe £ terminates in a chamber open at the bottom, and im- mersed sufficiently deep in a tank of water to keep it air-tight, but not to allow of water being drawn up into the heated retort, and passes through an outer pipe F, in which a current of water circulates IVom below njnvard, having its exit by a pipe at the top. As the retort becomes heated the volatilized mercury passes through the pipes -D and E, being condensed in its passage through the lattei-, and accumulates in the reservoir G, from whence it is drawn off by a bent tube. When the mercury has ceased to distil over, the retort is allowed to cool gradually, and when cold tlie , retorted silver is withdrawn, and it and the mercury which has passed over are weighed for the purpose of ascertaining if there has been any leakage from the retort. A sheet-iron hood is placed over the furnace- door to conduct any escaping vapors into the flues. According to Phillips, the cost of working from $ 45 to $ 50 ores by the pan process is, in those portions of the State of Nevada in which water-power can be obtained, nearly as follows ; — Per ton. Stamping wet, through No. 6 screens . . $ 1.50 Milling, including, the loss of mercury, etc. 5.00 Total cost including wear and tear . . $6.50 The loss of mercury amounts to from 1;^ to IJ pounds for each ton of ore containing sil- ver to the amount of from $ 35 to $ 50 per ton. The B.VRUEL Process as ap- plied to gold is exemplified in many forms. In Fig. 156 the gold is amalgamated in hollow revolving cylinders upon hori- 3^ AMALGAMATOR. 83 AMALGAMATOR. Fig. 156. csiy inder turns thereon. The pipe D connects with a retort, and conducts therefrom the mercurial fumes which pass into the cylin- der through perforations in the lower part of the pipe. The end D' of the pipe dips into a vessel of water that condenses any mercurial vapor which passes over when the stopcock g is opened. The cock regulates the pressure of vapor in the cylinder, which has a door by which it is charged and un- charged. Staats, March 13, 1866. Theore is placed in a closed vessel in company with an al- lowance of quicksilver, and is then rotated Fig. 169. Wright's Barrel Amalgamator. zontal axes, the trunnions being hollow to admit the pulverized ore from one cylinder into another. The cylindere are connected by flanges or S-pipes with grooves turned into the axes or trunnions, and rings are fitted into the grooves and covered by the flanges ; the whole are so connected as to make them water or steam tight, and so arranged as to give a fall of about six inches to each cylinder. The cyl- inders contain rollers, knives, burnishers, and other analogous arrangements to produce friction, scour the ore, and assist the contact with the quicksilver. Heath, February 17, 1863. This machine con- sists of a cylinder which rotates upon an axis diago- nal with the true cylindrical axis, and is formed with a corrugat- Fig. 157. ed interior sur- face, the corru- gations running parallel with the true axis and across the end ; it is al.so jirovided with annular ribs, which project from the inside of the cylinder 1 in a plane paral- - lei to the heads and at right an- gles to the axis of the cylinder. The effect of the obliquity of the axis of rotation is to make the contents slide ami roll as the raichine is rotated. A lid admits to the interior, and the latter is also entered by a pipe. Hall, February 28, 1866. The hoii^ontal rotat- Fig. 158. Heatk's Amalgamator. HalVs Cylinffer Amalgamator. ing cylinder A has internal lifters c c, which raise and turn over the pulverized quartz contained there- in. The central pipe is stationary, and the cyl- Stants^s Amalgamator. on its horizon- tal axis above the fire in the furnace. The fumeseliminat- ed by the heat from the mercury penetrate the material as it is agitated by the rotation of the vessel. Sturgf.s, September 18, 1866. The barrel amal- gamator has a pocket to retain the mercury and distribute it to the ore as the baiTel revolves. The cylinder is stayed by dia- metric bolts. Gold. The Battery Process. In the amalgamation of gold ' ores the auriferous quartz is broken by a crasher into pieces of about a pound weight, and is then stamped. For wet crushing, stamps are used weigh- Stmges's Amalgamator. ing from five to nine hundred pounds including the stem, and are driven at the rate of seventy blows per minute with a fall of from six to nine inches. They are fed by an attendant whose duty it is to regulate the supply of ore, water, and quicksilver, when, that metal is used in the bat- tery for amalgamating the free gold present. Amalgamation in the battery requires careful attention, principally to avoid the too rapid addi- tion of quicksilver, which should be supjilied in ver>' small quantities only. To amalgamate the free gold in a battery, the quantity of quicksilver to be used is about oiie ounce weight to each ounce of gold present ; this is suflicient to collect the gold and form a dry amalgam. If, therefore, a mill will stam]i twenty- four tons of ore in twenty-four hours, and the ore contain an ounce of gold per ton, it will be neces- sary to put into the battery an ounce of quicksilver eve'ry hour. Wlien, in addition to gold, the rock under treatment contains metallic silver, the amount of mercurv added must be proportionably incieased. Jlore than eighty per cent of the assay value of the gold in the ore may by careful manipulation be thus obtained. The gold amalgam accumulates in the. corners and crevices of the battery box, between the dies, on the breast of the mortar, over which the crushed ore is washed into the settling-cisterns, and is even found in considerable qunntities adhering to • the stamp-shoes. The amalgan. thus obtained is very hard and hea%'y, and is commonly so rich in AMALOAMATOF. 84 AMALGAMATOR. Dodgers Amalsamator. goUl as to be worth us nnicli as ten tlollars per ounce. The crushed ore is taken off from the mortar by a supply of water, e(iual to the run of J-inch pipe to each set of five stamps, passing through screens in the back and front of the box. These screens are made of thin Russia iron perforated witli holes punrlied by si'wing-needles. Auriferous sand is treated in divers amalgamating machines ; it being already in a comminuted state, it is not necessary to put it through the battery. DoriGK, May 3, 1S64. This invention relates to an anangement of the rotary-shoes of the machine, whereby the outer ones, which are subjected to the most wear in consequence of having the greatest speed, may al- Fig. 161. ways be ad- justed so as to run in contact with the bot- tom of the pan, and the wear tliereby com- pensated for. In the ordi- nary amalga- mating m a- chinestheout- ier shoes, in consequence of being subject- ed to more wear than the inner ones, soon become com paratively useless. The adjustable shoes are attached to supplemental bars, which are hinged to the radial arms D, and are also connected thereto by springs which pemiit ad- justment of the pressure. ifUccUaiuoiis Mnxhincs. The following are diverse in their constniction from those previously cited, and are not strictly referable to either of the classes, while partaking of some of the features of the "pan" anil the " barrel " process. Cn.\riLES, September 25, 1866. The inclined panners B are suspended by rods from the frame, and are oscillat- F'g- 182. ed by machin- ery. They dis- charge into a trough which leads the ore- dust and water to a giinding- pan. The ore and water enter the eye of the runner, and pass between it and the beil-plate to the periphery, at which they are discharged by a spout to a series of anialgamat- ing-boxes, each of wiiicli consists of a case A' con- taining a series of coiijier pans placed in vertical series. The ujiper muUer L has a rotai-y motion, and the lower one an oscillation, derived from the crank and pitman 0. The shell M, whose lloor forms the lower mulh^r, travels on rollers as it oscillates. BiiocK, May 1, IStill. The upper surface of the revolving disk c is divided into a number of recepta- cles, and the lower surface of the disk above it is rilibed. The respective disks i-evolve in different directions. The receptacles are filled with mer- • cury, and the action of the upper plate n is to feed tlie pulverized ore from the center continually to- wards the periphery, its gravity keeiiiug it as Charlen^s Amalgamator. Fig. 1J3. Brock^s Amalgamator. a film in contact with the mercury upon which it floats and travels. The disks are rotated by the engagement of their respective pinions with bevel- wheels on the driving-shaft. Battels, January 6, 1863. This apparatus con- sists of a .series of toothed annular ]ilates H I, secured to the casing of the machine and inclining down towards the center, and a corresponding num- ber of revolving toothed jilates E F, mounted on a vertical shaft, forming basins in which the mercury is contained and occupying the spaces between the stationary plates. The material to be washed Fig. 164. Battels's ]Vasker and Amalgamator. or scoured, falling on the outer part of the uiiper stationary plate, is acted on by the teeth of the revolving plate above, and passes inward by its own gi-avity until it falls on the center of the revolving plate E next below, whence it is carried outward by centrifugal action until it falls on the stationary ]ilate / next below, and so on to any extent re- quired. The vertical shaft is stepped in n lighter-bar, which is raised or lowered to adjust the proximity of the teeth on the rotating disks to those on the- stationary ones. The amalgamated metals collect in the central pockets, and are removed therefrom as they accumulate. PlETscH, May 3, 1864. The upper part of the AMALGAMATOR. 85 AMALGAMATOR. app aratus consists of a O double seiies of pans, the al- ternate ones revolving in different di- rect io n s. Each is smooth on its upper sur- face, but has teeth below, which agitate the material in the pan next b e - neath. The ore and water are compelled into a tortu- ous course, falling over the edge of each pan in the series, and being caught by the one beneath. After reach- ing the point 0, the ore is led in again to the center, and the action is repeated. The heavy particles accumulate at the bottoms of the pans, and are thence removed to the amalgamators below, wlieie tlijy are agitated by stirrers above and in contact with the mercury which oc- cupies the depressions in the bottoms of the pans ; the )i:i:is communicate by a cen- tr.ii channel. Kendhick, May 29, 1866. Theagitatori?' operates in the Picisck'fi Separator and Amalgamator. Fig. 167. Peck^s Amalgamator. ing platform. Each pan empties into the one next below it in the series. The belly of each ]'an has some mercury, and the combined vertical, longitu- dinal, and partial rotaiy movement is to settle the heavier matters to the bottoms of the jians and sliift the lighter material to the pans next below. The pe- culiar conjplex motion of the pans is intended to im- itate the hand motion in panning. Partz, July 14, 1S63. The powdered ore is dis- tributed in a dry state over the cuiTent of nicrcurv flowing upon the inclined surface of the metallic trough. The surface of the latter is amalgamated with mercury, and that which flows to the lower end is re-elevated and again distributed upon the trough. A current of water and an agitator-wheel assist in removing the tailings which reach the receptacle at the lower end of the trough. Fig. 168. =^. Fig. 166. Kendrick's Amalgamator, bottom of the tank, being driven by the vertical s'.iaft C and the gearing above. The box E occupies a I osition near the bottom of the tank, and is hoMtcd by steam introduced by the jiipe o. b is the disi/harge-pipe for the water of condensation. rr.ci;, February 21, 1865. The pans are ar- ranged in successive order upon steps on the swing- Partz^s Amalgamator. Hilt,, January 1, 1861. This operates by centiif- ugal action. The rotating basin has a central de- pression to contain the mercury, and its surfaces are amalgamated to cause adhesion of the amalgam, as it is formed by the contact of the mercury with the precious metals in the pulverized ore. The water, quartz, and lighter impurities are expelled over the edge of the basin by centrifugal force, while (he heavier, valuable results settle into thecentral pocket. Gahpiner, October 4, Fig- 1C9. 1864, subjects the finely pul- verized dust of ores, in connec- tion with mer- cury, to a powerful agita- tion and cen- trifugal action, by placing them in a par- tially covered revolving pan ; the form of the rim prevents the loss of the Hill's Amalgamator. AMALGAMATOR. 86 AMALGAMATOR. metallic portions, while the lighter impurities are ejected over the edge of the pan, into which a stream of water constantly flows. Whelpley and Storer, September 11, 1866. Fig. 170. interior surface by the centrifugal force, and the metallic particles are seized and amalgamated by the mercury. The supply is derived from the tank T by pipe P, Whflpley and Storer's Amalsamator. The outer cylinder is supported on shaft attached by a hub to an internal plate. The interior of the Fig. 171. Phelps^s Amalgamator. cylinder is coated with mercury ; the pulp, being introduced during rapid rotation, is spread over the Fig 172. and the tailings dis- charged by pipe S. Phei.p.s, October 18, 18-46. The low- er roller revolves in a trough of mercury C, and distributes it upon the upper rollers A B, wliieh are brought into an electric circuit to in- crease their attrac- tive energy in accu- mulating the adlier- Day's Amalgamator. Adams and Worthington^s Amalgamator. ing amalgam, which is subsequently scraped ott' and falls into the receiver 0. The pulp is supplieil to the u])per roils through a spout proceeding from a tank J. The jackets hold the ores to the rollers for a spe- cific portion of their revolution. Adams and Wouthington, February 12, 1864. This invention consists in pulverizing the quartz or metalliferous substances containing ])recious metals to an impalpable powder, and precipitating and discharging this dust either in a calcined or otherwise prepared condition, in order to isolate the metallic particles from tlieir sulpliuious or other foreign combinations, into an atmos- phere of hot vapor of quicksilver. On the u]i- per end of a vertical stationary cylinder is fitted a short cylinder, which is made to turn therein, the same being provided with a screen or liojijvr. Below the stationary cylinder is a pan in which stirrers are made to o])erate. Communicating with the main cylinder, by means of a tube placed a little below the screen in the upper cylin- der, is a furnace or still for distilling the quick- silver which falls with the calcined particles of ore through the stationary cylinder. Day, September 26, 1865. The retort is set in a furnace A, and delivers fumes of mercury into the vertical tube D. The pulverized ore from the hopper C is delivered by a feed-wheel in graduated quantities, and falls the length of the tube, at the lower end of which it is deliv- ered by a discharge-wheel, so that the fumes may not escape. The length of the tube may be such as is found sufficient for the purpose, AMALGAMATOR. 87 AMALGAMATOR. and the respective wheels E F are connected by a driring-chain. The particles of the precious metals combiiie, in falling, w-ith the mercurial fumes with which the tube is charged. Hall, December 27, 1864. This invention con- sists of a series of curved pipes connected with quicksilver basins in such a manner that the lower end of the upper pipe and the upper end of the second pipe will enter the bottom of the first basin, the end of the other pipe extending slightly above Fig. 174. HaWs Amalgamator. the bottom of the vessel. The lower end of the latter pipe and the upper end of the pipe A enter the bottom of the pan, and so on throughout the whole series. He claims an apparatus for separating gold from foreign substances, composed of a series of bent pipes or tubes combined by means of a series of connect- ing-basins containing quicksilver. To aid the proc.ss of amalgamation various pro- cesses have been adopted to render desuljihurization by roasting more etfective, among which may be cited the following : — Raht, August 21, 1866, forces air through the mass of fused metal, to remove sulphur, arsenic, and antimony. The apparatus may be similar to the " Bessemer." Ryers'in, August 14, 1866. The ores are heated in a muffle in the presence of a current of air ; behind each muffle is a passage in which binoxide of nitrogen is generated, which mixes with the air and sulphurous acid passing from the muffles ; the mixture is driven by fans into receivers in company with a steam-jet. The receivers are charged with ore previously desulphurized in the muffles. The sulphurous acid is converted into sulphuric acid, and combines with the base metals in the receiver ; the sulphates are dissolved out by water, leaving the gold free ; the silver may by the usual method be afterwards precipitated from the solution of mixed sulphates. Wheli'lf.y and Stoker, September 11, 1866. In this process the chemical reagents are blown in a finely divided state upon the heated ore by means of a blast of air or steam. The interior of the fur- nace is stated to have an atmosphere charged with " coal in aerial or air-borne combustion." Fleury, July 3, 1866, mixes the sulphurets or tailings mth coal-dust, and bakes them into a metalliferous coke. This is ground, heated, and treated with steam, after which it is amalgamated. Brower and Campbell, January 23, 1866. The ores are smelted with a suitable flux, such as carbo- nate of soda, and the fused mass precipitated into cold water, to disintegrate the mass and e.xpel the sulphur. Whelpley- and Stoker, September 11, 1866. The cylindrical vessel is connected with a hopper at one end, an exhaust-pipe at the other end, and hns a series of rotary agitating arms attached to a shaft passing through the said cylinder. The hopper has a grating and a feed-brush. Air may be admitted to the cylinder through a grating. The inventors claim, lirst, brightening metallic particles in finely pulverized and desulphurizeil ores, when such brightening is effected on the prin- ciple of mutual attrition in a cylinder alternately closed during the brightening process, and opened to set flee the charge by means of a valve in the exhaust-pipe, intending to claim for this end the principle of alternately closing and opening the cylinder, so as to do the work in a close cylinder, as well as the comliination of the cylinder-valve and exhaust-pipe for the purpose and substantially as described. A fine grating prevents in the feed-hopper the passage of any but very fine dust into the cylinder. In their patent of June 13, 1865, they separate metals from mixtures of earth and metal by the action of gravity in counteraction to currents of air in an upright pulveriziiig-mill, the air mov- ing upward to carry oft' the finer dust of earthy matter, while the metal falls by its supeiior gi'avity. Within the cylindrical case is a revolving shaft provided with blades. The ca.'^e is provided with a hopper and an air-aperture at the top, and an air- outlet and an outlet for the oie through the con- ductor at the bottom. The conductor communicates with a box, which is provided with an air-aperture and door. This box communicates with another box by means of a pipe, the latter box being also provided with an air-aperture and a door. A tube leads from this latter box to the center of a spray-wheel which is contained in a box, the bot- tom of which is covered with water, and the said box is provided with .shelves in the upper part. The same inventors have an apparatus for desul- phurizing ores, by roasting, while falling through a chunney above a furnace. Electric action has been called into play to secure the deposit of gold and silver from the earthy mat- ters witli which itis associated, and has I^'g 1"5- also been used to energize the action of the amalgam. C'OK.soN, May 5, 1868. The ores" are containedin an in- sulated pan or bar- rel, and subjected to electric action therein. The bat- tery is formed in the jian, and is in- dependent of ex- terior influences, the anode and cath- ode being exposed in the slime and amalgam, and con- nected by a metal- lic strip. Corson's Amalgamator. AMALGAMATOR. AMALGAM MANIPULATOR. For other ailairtations of Electro-Metallurgy to the eollection of the precious metals, see Gold and SiLviiK, Electro-met.\llurgic Processes for CoLLIXTlON OF. Ill Kye];son's apparatus, June 4, 1861, the sub- stance containing the gold and silver is intioduced into the cylindrical vessel, provided with a hemi- spherical or dished bottom, in a finely divided state, together with mercury and water. Superheated steam is introduced by the coiled pipe into the bot- tom of the vessel, escaping into the mass by a series of small holes. The vapor of the mercury is con- densed against the bottom of the cover of the vessel, and fa Is in a linely divided state through the mass. The extraction of tln^ precious metals by immers- ing the powdered ore in a lead-bath has been calletl amalgamaiiou, but the term is incorrect ; it forms an alloy, not an amalgam. It will be considered under Le.\d Process for Extraction of Pre- cious Metals. Buusill's English patent of February 12, 1853, describes a mode which partakes of a combination of the mercurial and lead processes, and may be men- tio leil liere. Hj treats a'.iriferous and argentiferous ores with an amal.;ani firmed by the union of mercury with a readily fusilile alloy of lead and bismuth ; or lead, bismuth, and tin. The ore is immersed in the bath of nudten metal. The lead process preceded the mercurial, at least on this continent, having been practised from time immemorial by the Indians of Peru. Heister'.s new process for the reduction of ar- senical sulphurets and other refractory ores is thus described by the San Francisco Times. "To all outward appearance the machine is very simple, consisting of three barrels, one of cast-iron and two of wood. The iron cylincler is about half filled with sulphurets or pulverized ore, and revolved over a moderate fire for an hour, keeping it below a red heat. The ore, having been thoroughly heated through, is drawn out into a wooden cylinder, and ten iicr cent of cjuicksilver added, and the opening then made air-tight, to prevent the fumes of the ipiicksilver from escaping. After revolving for two hours, the ore and (piicksilver are found to be intimately mi.xed together, and the gold and silver a'nalg.imated. The charge is then drawn off into the third barrel and diluted with water, and after revolving for two hours the quicksilver and amal- gam are drawn off. The secret of tliis process is in this last barrel, used as a settler ; for, in every in- sta'.icu', with the most refractory arsenical sulphu- rets, and with comliiuations of lead and iron, the i[uicksilver is found at the bottom, collecting and forniiiig an amiilgam containing over ninety per cent of the gold and silver, while the only appreciable lo.ss in (piicksilver in a month's working was what was spilt by carelessness outside. The cost of working live tons a day onglit not to exceeil S 30. A live- horse engine would give an excess of power, and by grading the barrels properly two common laborers on a shift could keep the machine going to full capacity." A process saiil to yield excellent results was described in the " Alta Californian " of August 30, 1866. See also "American Journal of Mining" (now the "Engineering and Mining Journal"), Vol. II. p. 43 el seq. " The dry rook is crushed, and afterward submitted to the a 'tion of balls in a drum to insure full pulver- ization, it being desirable that the ]iowder should ap- proach as iii'ar the fineness of wheat- flour as possible. A charge of this ]iowdered quartz is then placed in an iiir-tight cylinder, the interior of which is fur- nished with a worm of pipes to convey superheated steam therein. Added to the charge is a given (juantity of quicksilver, which is first heated by the introduction of ordinary steam ; the super- heated steam is then turned on, and the whole seethed or boiled for an allotted period. On the top of this cylinder a water-bath is placed, and a; the mercurial vapors rise they become condensed. Thus the system of thoroughly impregnating the crushed rock with quicksilver is carried out with efficiency. After thus cooking, the cylinder door is opened, and the whole mass discharged upon a novel shaking-table, which is worked by the power of the steam employed in the previous operation. This table is built of copper on a wooden frame, with rollers and riffles of peculiar constniction, which, when it is in motion, give the water, amalgam, and dust the same action as the ocean-surf, — an under- tow. As the mass descends, the amalgam, from its metallic weight, gradually clears itself from the quartz-dust, and the result is, that it is all col- lected in the troughs of the riffles, containing every particle of metal, he it precious or base, the quartz holds. The mode of a]iplying super-heated steam to the crushed rock desulphurizes it, freeing the metals, and 'all that is necessary is to retort the amalgam to obtain the result of the yield." The "Journal of Mining," August, 1868, mentions the following as a reported success, but without vouching for it : "Zinc added in small quantities to the quicksilver used in amalgamation augments, in a remarkalile degree, the retentive power of the latter for gold and silver. It is stated that one ounce of zinc, or less even, should be used to ten pounds of quicksilver. The action in this case is said to be about the same as when sodium amalgam is em- ployed. The beneficial result is thought to lie in the fact that zinc has a tendency to crystallize in a needle or barb-like form ; hence, when disseminated in minute particles through the quicksilver, the power of the latter to take up the atoms of gold and silver with which it may be brought in contact becomes very much intensified. This method of in- creasing the efficiency of the amalgamation process is said to have been in vogue in the Mexican mines." Many valuable imijrovements have first been no- ticed in the current journals of the day, the " Engi- neering and Mining Journal," "Scientific Amer- ican," and " American Artisan." Books and their editors cannot keep jiace with the march of improve- ment, which is incessant, and naturally finds its expression in these scientific pajiers. See also "Mines, Mills, and Furnaces," by R. "W. Raymond, United States Commi.ssioner of Mining Statistics : J. B. Ford & Co., New York. A-mal'gam, E-lec'tri-cal. For covering the cushions of electrical machines. Zinc, 1 oz. ; grain tin, 1 oz. ; melt in an iron ladle, and add mercury, 2 oz. Stir with an iron rod, jiour into a wooden box chalked on the inside, and agitate till cold ; or stir till cold, and then powder. The powder is spread on the cushion, which is previously smeared with t.allow. A-malgam Gild'ing. Grain gold, 1 ; mercury 8 ; unite by gentle heat and stirring. In using, first rub the brass, copper, etc., with a solution of nitrate of mercury, and then spread a film of amalgam. Heat volatilizes the mercury and leaves the gold behind. A-mal'gam Ma-nip'u-la tor. A dentist's in- .strument to facilitate the prejaration of amalgam for filling excavations in carious teeth. It has a cup at one end for taking up the desired amount of filings or powder, and a curved spatula at the AMALGAM SILVERIXG. 89 AMBULANCE. other end for combining the mercury with the filings and packine it in the cavity. A-mal'gam Sil'ver-ing. Silver, 1 ; mercury, 8 ; mix with heat, and stir as with gold. Apply as the gold amalgam, previously using a wash of nitrate. For silvering the insides of hollow glass vessels, globes, convex mirrors, etc. : — Lead, tin, and bismuth, each 1 part ; melt, mix, and cool to tlie lowest point at which the alloy will remain fluid ; add mercury, 10 oz. Warm the glass, pour in the amalgam, and roll the glass round and round. The amalgam will adhere readily at a cer- tain temiiei-ature. A-mal'gam Varnish. Melt grain tin, 4 ; bis- muth, 1 : add mercury, 1 ; and stir till cold. Grind fine with white of egg or varnish. A-man'do-la. A greeu marble haviug the ap- pearance of a lioney-comb. Am-a-sette'. A horn instrument for collecting painters' colors on the stone. Am'be. A raised stage for a rostrum. An old chiraigical machine invented by Hippo- crates for reilucing luxations of the shoulder. Amtro-type. A picture taken on a jilate of prepared glass, in which the lights are represented in silver, and the shades are produced by a dark background, visible through the unsilvered portion of the frlass. — Webskr. See Photogkaphy. Am'bu-Iance. Late events in the United States have directed attention to means for the trans- poitation and care of the sick and wounded. Deal- ing strictly with the mechanical aspects of affairs, it may be stated at once that ambulances are of three kiuds, four-wheeled, two-wheeled, and those adapted for pack-saddles. Fig. 176. Moseses Ambulance. Moses, September 28, 1858. The. sectional fold- ing-seats are arranged along the sides, and may be converted into couches. Hammocks form an u]iper tier for patients. An adjustable door serves for a table. The surgeon's medicines and implements are carried in cases, which fit in and under the seats, or in di-awers under the body of the vehicle. The water-keg is suspended beneath the rear, its faucet defended by tlie step. McKe.\n', October 11, 1864. The stretchers are run in longitudinally up- on rollers, which rest upon a false' bot- tom suspended by rubber springs from the sides of the carriage. The water- vessel is sufficiently elevated to supply the wounded by a flexible pipe which is under their control. A fan is sus- pended from the roof. The side-slats are vertical and are controlled by a sin- gle rod ; their beveled edges enable them£ to shut closely and present plane exte- rior and interior suriaces. Arnold, April 5, 1864, suspends his cots upon pivots, which enable them to swing in accordance with the inclina- tion of the ground, so as to avoid the rolling mo- tion of the patient. The pivots themselves rest on springs, w:hich give some resiliency when the car. riage receives vertical motion, and thereby lessen the jar. RucKER, Allen, and Smith, November 6, 1866. This is a double or single tier ambulance. Each couch of the „ ... lower tier is ili- '■ — ~ ' vided longitu- dinally and hinged. It may lie flat upon the floor, wliile the upper tier is occu- pied b}- other patients ; or it may be bent so as to form a seat and sup- port, while the stretchersofthe upper tier are placed on edge against the car- riage sides and form backs for the seats. The sides are separately adjustable. The two-wheeled ambulances are spring carts with provision for recumbent or sitting patients. Hayward, May 16, 1865. The stretchers may be adjusted for recumbent or sitting patients, the legs operating to support them in either capacity when the stretchers rest on the ground. The pack- saddle has wedge-shaped sockets to receive cor- responding wedge-shaped blocks on the legs of the stretchers. Sis, 1863, WiLKiNS, 1864, Slatter, 1865, and others have patented improvements which might be cited would room permit. This description of sennce was brought to great efficiency by Baron LaiTey, during the wars of Napoleon 1. The experience was almost lost in the peace interval, judging by the ambulance arrange- ments in the Crimea, 1854. At the battle of the Alma, in which 1,986 British and 1,360 French were killed or wounded, the generals of both armies Fig. 178. RtKlcer AUtn. and SmiOCs Ambulance, HayxcaTfTs Ambulance, AMBULATOR. 90 AMMONIUM. appeal' to have been taken by surprise. The Eng- lish were least efficient, the French improvised chairs or panuiera slung over tlie liacks of mules, like one of the illustrations precedinf;. Our own service, IStJl -65, was well performed, after things got in running order. Perhaps the Crimean heroes might say the s;ime, with the concluding proviso. Am'bu-la'tor. Sometimes cal led a perambulator. An iiis..\iment for measuring distances. See Odume- TEii. The word " amlnilator" is often erroneously ap- plied to a velocipede, ami to a traction-engine, whose mode of propulsion is by oscillating bai-s whose feet come in contact with the ground in .somewhat similar manner to the natural action of the legs of animals or of man. The light carriages driven by hands or feet will be considered under the heading ViCLOcu'Enij. See also Traction-enoin'e. A-mer'i-can Leath'er. An enameled cloth im- itating leather. .Am'i-ci's Prism. A glass piism mounted be- neath the stage of a micj-oscope to obli(inely illu- minate an object beneath the stage. The prism has a llat-bottom side and two lenticular sides, com- bines the refracting ami retlecting powers, and thniws a converging pencil of rays ujion the object. It has three adjustments : one on a horizontal a.xis to ilirect the rays upward at the required angle ; one for distance from the axis of the microscope, to vary the oblifpiity ; one by rotation on a vertical a.xis, to determine the direction whence the rays shall proceed. Am mo-Di'ac-al En'gine. This motor seems to be yet in an inchoate state, but has received some attention in Euro]ie. The machine described is the invention of M. Froment. The London " Mechanics' Magazine" thus refers to it (it appears to have been at work — or rather in action, for it was not usefully employed — at the Paris Exposition) : "Strong liquid ammonia is used in the boiler, and the vapor generated is said to be a mixture of at least eighty parts of amniouiacal gas and twenty parts of steam, so it may be fairly called an ammo- ni.ical engine. The principal recommendations of ammonia, when applied as a motive-power, consist in the small amount of fuel rehic News. Am'pli-tude Com'pass. An azimuth compass whose zeros of graduation are at the east and west points, for the more ready reading of the amplitudes of celestial bodies. Am-pul'la. Any vessel having a belly, as cucur- bits, receivers, etc. Am'pu-ta'ting-knife. A long, narrow-bladed knife used for making the incisions in amputations. The ancient surgeons endeavored to save a covering of skin for the stump by having it drawn upward pre- vious to making the incision. In 1679, Lowdham, Fig. 179. ^^^^aX2 Amputalinq-Knife. of Exeter, England, suggested cutting semicircular Haps on one or both sides of a limb, so as to pre- serve a fleshj' cushion to cover the end of the bone. Both these modes are now in use, and are called the "circular" and the "flap" operations. The latter is the more frequently used. Amputation was not practised by the Greeks ; at least, Hippocrates (B. C. 460) does not refer to it and did not practise it. C'elsus notices it (A. D. 30). Cautery, pitch, etc. were used to ar- rest the bleeding. The needle and ligature were introduced about 1550, by the French surgeon Fere. AMrUTATING-SAW. 92 ANAESTHETIC APPARATLTS. He was surfjeon to Henry II., Francis II., Charles IX., iiiiil Henry III. of France, and though a Protes- tant was concealed in the king's chamber on the night of St. liartholoinew. The king is said to have itniarked, "There is only one Pere." A com- plete bet of surgical instruments of bronze was discovered at Pompeii. The tournicjuet was in- vented hy Morelli in lt)74. Ba.s.so-rclievos in the temples of Karnak, Tentyra, and Lu.\or show that the ancient Egyptians per- fornjed amputations of limbs, without the tourniipiet, liowevcr, or the mode of ligating the severeil arte- ries ; it is merely a cutting and sawing, followed by the cautery, styptics, or compress. The chirnrgeon of ancient times was principally emjiloyed in reducing fractures and lu.xations, in treaiiag wounds, ajiplying topical remedies, and in the application of simple or strange drugs with occult charms and pow-wows. One form of amputating-knife found at Pompeii in 1819 had a thick back and a wavy edge, and is suppo.scd to have been used by the blow of a mallet on its back. Am'pu-ta'ting-saw. Amputating-sawsare niod- ifiaitious of the tenoii,, frame, joint, and crown saws. They are of Fig. 180. Amputating- Saws. Sizes from 4 to 14 inches in length. Some have edges more or less curved, and the smallest of these dwin- dle down to a nearly circular plate of steel less than one inch in diam- eter, serrated round the edge, e.xcept where a slender shank terminating in a wooden han- dle is riveted to the edge of the saw-plate. These are known as Hey's saws, and are used in making exsections, operatii ^ on the cranium and metacarpal bones, and in rcmov" ing carious bones from deep-seated places. Am'u-sette'. A stocked gun mounted on a swivel, and carrying a ball or chaige of buck-shot of from 8 to 32 ounces' weight. An'a-bas'ses. (Fabric.) A coarse blanketing nuidc in France for the African market. An'a-clas'tic Glass. A sonorous, flat-bel'ied glass made in Germany, having a thin, flexible, slightly convex bottom, which is ca])able of flapping back and forth by the expiiation or inspiration of the breath when the mouth is applied thereto. As the bottom is drawn in or out it makes a loud crash. An'a-cos'ta. (Fabric.) A woolen diaper made in Holland for the Spanish market. An ses-thet'ic Ap'pa-ra'tus. Anaesthesia is a term made use of in medicine to denote a deprivation of sensibility to external impressions, affecting a part or the whole of the body. In some nervous diseases a portion of the body may become jiar- tially or totally insensible to pain, while the sensi- bility of another part may become excessively acute, or in a state of hypersesthesia. The division of a nerve, as is well known, produces an entire depriva- tion of sensibility in those parts of the body de- pendent on it. When the insensibility is confined to the surface of the body it is termed pcrijiliern! ; but when aris- ing from a cause acting on the brain or s|iinal mar- row, from one or the other of which all the nerves enumate, it is called central. Means for inducing temporarily either of these conditions with safety to the patient have been long sought for in surgical practice. The Indian hemji, Cannabis Indica, was anciently employed ; and it appears that the Chinese employed some prepara- tion of liemp for producing insensibility during surgical operations, more than fifteen hundred years ago. Mandragora was used by the Greeks and Konians for the same purpose, and appears to have continued in use, in combination with ojiinm and other drugs, so late as the thirteenth century, the patient inhaling the vapor from a sponge saturated witli these substances. The mandragora, however, at times induced convulsions, and though mention is made of its ana'sthetic powers for producing a "trance or a dee]ie terrible dreanie," in ojierations for the stone, toward the close of the sixteenth cen- tury, it, or similar agents, appears to have gradually gone out of use. It seems a little singular that sulphuric ether should not have been employed for the jiurpose for some three centuiics, unless, as has been sug- gested, it is the substance sjioken of by John liap- tista Porta of Naples, who published a book on Natural Magic in 1597 ; this "rjuintessence " was extracted from medicines by somniferous " men- strua," and was kept in leaden vessels tightly closed to prevent its escape. The cover being removed, it was applied to the nostrils of the sleeper, who was thereupon thrown into the most profound sleep, etc., etc. In 1784, Dr. Moore of London tried the expedi- ent of compressing the nerves of a limb preparatory to amjjutation ; but this caused much pain. Narcotic poisons will induce ana'sthetic condi- tions of the body, in which surgical operations may be performed without apparent jiain to the subject. The same is true of alcoliol. The ]>eculiar nervous condition induced by what is called aninuil magne- tism has also produced insensibility to pain, during wliich operations have been performed. The modern anesthetic agents are : cold applica- tions, protoxide of nitrogen (laughing-gas), chloro- form, ether, amylene, kerosolene. .Sir Humphry Davy suggested the use of protoxide of nitrogen as an ana;sthetic afjcnt in surgical operations. It was used by Dr. Wells of Hartfonl, Conn., in 1844, in dental ojierations. It has now attaineil gieat favor. Chloroform is a terehloride of formyle (the hypo- thetical radical of fomiic acid). Its discovery is claimed by Soubeiran, Guthiie, and Liebig, whose claims have about an even date, 1831. The verdict seems to have settled in favor of the former. Its first use as an anaesthetic was by Dr. Simpson of Edinburgh, 1847. Hydrate of chloral has recently become quite un- pleasantly prominent in the list of anodynes, seda- tives, and hypnotics. Ether was known to the earliest chemists. The discovery of its use as an antesthetic was made by Dr. Jackson or Dr. Morton of Boston, in 1846. .\ contest ensued between the parties to ]>rove pri- ority, and was much debated in the scientific jour- nals of the day. In an apjilication to Congress for a remunerative appropriation of $100,000, tlie rep- ANAESTHETIC REFRIGERATOR. 93 ANALYZER. resentatives of Dr. Wells came in with a claim to the first in- vention. The enterprise failed, hut mankind owes a debt of gi-atitiiJe to each. Amylene is a colorless liquid obtained by distilling fusel oil with chloride of zinc. It was discovered by M. Balard, of Paris, in 1844. Fii'st used by Dr. Snow in 1856. Kerosolene was derived from the distillation of coal-tar by Mer- rill of Boston. Its use as an an- ffisthetic was made known in 1861. Nitrate of ethyl, of which the chemical formula is C« HsO, Noc possesses remarkable antesthetic properties ; it has a very fragrant and agreeable smell, a sweet, but a bitter after taste. Its boiling-point lies at 185° Fahr., and its specific gravity is 1.112 at 62.5° Fahr. It burns with a white Hame, is not soluble in water, but easily so in alcohol. Various forms of apparatus are used in the admin- istration of anaesthetic agents. Some consist of cups which contain the sponge saturated with the liciuid and exposed to the current of air as it passes to the lungs. Others pass the air through a body of liquid. The administration of nitrous-o.xide re- quires a ditferent arrangement, and the tube con- necting the bladder with the mouth-piece has valves so arranged as to pass the gas to the mouth during inspiration, and allow the e.'ipired breath to pass to the atmosphere instead of contaminating and weak- ening the contents of the bag. These are more properly considered under In- HALEKS (which see), as that has become the term by which they are generally known and patented. A class of inventions which preceded the inhalers just described are termed Respikatoks (which see), and are not adapted for the introduction of aiiaisthetic or curative medicaments into the lungs, but arc intended as air-heaters or filters, and are used by two classes of persons, — by consumptives to temper the rigor of the air in cold weather, by causing the air to rush rapidly through a succession of narrow passages ; and by mechanics, cutlers especially, to arrest particles of steel and grit which permeate the air where the grinding is carried on. The anaesthetic apparatus which operates by topi- cal application of cold is ordinarily in the form of an Ai'OMiZEP. (which see), and consists of a tube whose lower end communicates with a body of liquid, and whose Contracted upper end is exposed to a blast at right angles to the axis of the upper tube and across the orifice thereof. This has the ett'ect of raising the liquid, which is dis|)ersed as it reaches the opening, and, a.ssuming the form of fine spray, becomes a great absorber of sensible heat, and consequently lowers the temperature of the air in its vicinity. The air, thus cooled, is projected upon the part where local anesthesia is required, and by absorbing the heat of the part renders the nervous system of the part incapable of feeling, calloused by cold. Bags of ice have been laid upon the part affected to produce insensibilitj' by freezing. For freezing mixtures, see Ice, Manufacture of. An'ses-tbet'ic Re-frig'er-ator. An appara- tus for producing local aniesthesia by the application of narcotic spray. The apparatus consists of a bottle to contain the ether or other Uuid to be used ; through a perfo- Fig. 181 Whitens Anasthetic Rffri^erator. rated cork a double ttibe is passed, one extremity of the inner part of which goes to the bottom of the bottle ; above the cork a tube, connected with the bellows, pierces the outer part of the double tube, and communicates by a small aperture at the inner end of the cork with the interior of the bottle. The inner tube for delivering the ether runs upward to the e.xtremity of the outer tube. When the bellows are worked, a dnuble current of air is produced ; one cun-ent descending and jiress- ing upon the ether, forcing it along the inner tube, and tlie other ascending through the outer tube and plaj-ing upon the column of ether as it [asses li'om the inner tube. Put the ether into the bottle, nearly filling it, then insert the tube with the cork firndy, and fit tlie nozzle to give the jet desired ; the bulb on the extremity of the rubber-tubing, being now grasped in the hand and rapidly used as a hand-bellows, — the other bulb acting as a reservoir, — keeps uj) a steady pressure upon the ether and produces a con- tinuous j t. The small wires, called stylets, are used to (Traduate the spray, which is made finer or heavier by tl ; use of the •different sizes. Remove the nozzle and insert the stylet in the small tube. The hook on one end of the wires is to prevent their slipping into the tube. Two nozzles accompany the instrument ; the straight one for prodilcing a single jet, and the double curved one for operating on both sides of a molar tooth. An'a-glyph. .A. chased or embossed ornament. An'a-glyp'to-grapll. .•\n instrument for making a medallion engraving of an object in relief, such as a medal or cameo. A point is passed ovei- the medal at an angle of 45°, and comnmnicatcs motion to a diamond etching-point. The diamond partakes of the motions of the tracer, following the curves of the object, making the lines relatively ojien on the sides of the protuberances ujion which the light is supposed to strike, and making the lines closer on the sides opposed to the light. See Me- UAi.Lic Engkavixg. A'nal-di-la'tor. {Surgical.) An instrument for dilating tlie sphincter muscle for the examination of hemorrhoids or fistula in ano. An'a-lem'ma. A fonn of sun-ilial now disused. A'nal-spec'ulum. {Surgical.) An instni- ment for distending the anal opening to expose the inner surface of the rectum, in case of hemorrhoids, fistula in ano, etc. See Speculu.m. An'a-lyz'er. The upper or eye prism of the polarizing apparatus. The first of the two columns in the Coffey Still ; the second being the rectifier. See Still. ANAPLASTIC INSTRUMENT. 94 ANCHOR. An'a-plas'tic In'stru-ment. For the ojiera- tiori of foiminc; a nose iinon tlie face. The Taglia- cozzinn operation. Sfe RHIN'oi'LAsTtn PrN. An a-8tat'ic Engrav'ing and Print'ing. In- vented by Wood in ISil. An engraving or other printed sheet is moistened with dihite (iliosjihorie aeid, and pressed on to a clean surfaee of zine, wliieli is etelied thereby in the place not protected by the ink. The plate is kept damp by acidulous solution of gum, and in the printing process only takes ink from the rollers at the points where the ink of the original imjiressiou first adhered. Zincography is the term applied to drawing upon zinc for s\ibsequent treatment as above. An'chor. 1. Anchors were, according to Apol- lonius Khoilius and Stephen of Byzantium, origi- nally made of stone, or of logs of wood covered with lead. These were succeeded by a bent rod with a single fluke. The invention was ascribed by Pliny to the Tuscans ; Strabo ascribes the addition of the second fluke to Anacliarsis the Scythian. They were first forged in England, A. D. 578, when Titillus reigned in East Anglia. The general shape of anchors is well known, consisting of two arms terminating in broad expansions termed Hukes, and attached to a long shank, to which is fixed a stork of wood or iron at right angles to tlie arms, to insure the perpendicularity of the Hukes when the anchor is on the bottom, in order that they may take firm hold of the gi-ound. Small anchors termed grajmels, and having four or more arms, are used for boats, and at times for small vessels. The mushroom-anchor, so called from its shape, is much employed in the East Indies by the native vessels called grabs. The weight of the largest anchors, for vessels of 1,000 tons or less, is about 1 cwt. for each 20 tons measurement, or .0025 of the tonnage. Various improvements have been pro- posed upon the ordinary anchor, of which the most pronunent are Rodgers's, Trotman's, and its modi- fications, Isaaes's and Lenox's. In Tuot.man's anchor the arms are passed through the shank, which is slotted, and are held by a liolt, thus bringing the uppeT ann and fluke down on the shank, and allowing the lower one to penetrate deeper when the anchor is on the bottom. Fig. 182. ii lyotman's Anchor. This arrangement, aided by the horns on the back of the flukes, also prevents fouling. At a trial made in 1853, under the au.spices of the British Board of Admiralty, to determine the comparative general merits of various descriptions of anchors, their comparative merits were decided to be as follows, the Admiralty anchor being taken as unity : — Trotman . . 1.28 Houibal (or Porter) 1.09 Rodgers . 1.26 Aylen . . 1.09 Mitclieson . . 1.20 Admiralty . 1.00 Lenox . . 1.13 Isaacs . . .73 Notwithstanding the numerous recent modifica- tions claiming to be improvements, an anchor differ- ing little from the old- fashioned type, excepting Fig. 183. that even the very largest fl sizes have iron stocks, 11 still maintains its place (Jsj) both in the navy and merchant sei-vice of the United States. Anchors require to be made of the very best and toughest wrought - iron. They are made by welding together a fagot of bars under a steam or trip hammer, the smaller ana more difficult portions be- X^iK^ ing shaped and rounded -^^.^^ off, and the whole anchor finished up by hand. This portion of the work, es- English, Admiralty Anekor. pecially in the case of a large anchor, is one of the most arduous labors of the smith's shop ; as the workmen are unable to stand the intense heat from the huge mass of red-hot metal and wield the ponderous sledge-hammers employed but for a very short space of time, each strikes his blow and falls hack to make room for another, who in turn retires to give place again to his predecessor, and so on until the iron becomes too cool for further hammering. This evidently recpiires a considerable share of strength, activity, and endurance on the part of the men, who are not only compelled to strike while the iron is hot, but have to put in as many and as heavy strokes as they possibly can in the time. IsAACs's anchor has a flat bar of iron from palm to palm, which passes the shank elliptically on each side, and from each end of the stock to the njid- length of the shank are fixed two other bars to pre- vent fouling. Fig. 184. Isaaes's Anchor. ANCHOR. ANCHOR. Porter's anchor, or Honibal's as it is some- times called from the purchaser of the right, is very similar to Trotman's (which see), the latter being au improvement upon Porter's, with some Fig. 185. Lenoxes Anchor. modifications in the shape of the flukes and their horns. Lenox's improvement (1832-39) con- sisted in an improved Kg. 186. while the other arm falls down upon the shank, obviating the danger of fouling and by means of the curved bar assisting the first arm to bear the strain. Williams^s Anchor. mode of welding, and in rounding off the sharp edges and lines; also in reducing the size of the palms, the object being to obtain a stronger anchor and prevent injury to the cable. RoDGERs's anchor has a shank with a wooden core, for giving more surface, and con- sequent strength for a given weight of metal. WiLLi.\Ms's anchor, patented March 16, 1858. This anchor has three flukes hinged to a block at the lower end of the shank, and so set that two of them may penetrate the ground at the same time, while the third falls down upon the shank to prevent the cable from being fouled. The flukes are set at 120° apart and hinged in a sep- arate block. Morgan's anchor, patented June 21, 1864. The arms are separately pivoted near the end of the shank, and are con- nected by a curved bar passing through a hole in the shank. AVhen one fluke has hold of the ground its arm rests against and is supported by the crown-piece, Fig. 188. Fig. 189. Morgan^ s Anchor. MarshnlVs Anchor. Marshall's anchor, patented October 17, 1865. Antedated March 6, 1865. The arms are straight and tnm in an arc of a circle, moving separately on a pivot passing through the crown. Each is provided with harlis or projec- tions to help the fluke to take and retain its hold, and the oscillation is checked b}' cusjis on the thick portion of the crown, so that the arms have a given inclination to the shank. Latham's an- chor, patented August 21, 1866. The shank J B is made of two pieces, which separate at their lower ends to al- low the passage of the middle fluke. The arm C turns in the shank and has three parallel flukes. The weight by| these means is concentrated at the lower part of the anchor. When the anchor is let go, the flukes make about a quarter of a revolution, lying in the posi- tion shown in the illustration when they enter the ground. The shoulder on the crown-piece comes against the shank and restrains the oscillation of the arms in either direction, and the anchor stows com- pactly b)' bringing the arms parallel with the shank, the middle arm or fluke lying in the space between the two portions of the shank. Stuard's anchor. Among the single-armed an- chors may be mentioned Stuard's (English), which has a very short shank made in one piece with the arm, the pile being bent, but not welded. The stock is a wrought-iron bar with knobs on the end, which cant the anchor so that its fluke penetrates the ground as it is dragged along. One hole in the Latharn's Anchor. ANCHOR. 96 ANCHOR, SUSPENSION-CABLE. sh.ink is for attachment of the cable, and a shackle at the crown is for the buoy-rope. The largest inchor in tlie world, according to Charles Kyland's " Iron Trade Report," was made at H. P. Parke's Works, Tipton, Startbrdshire, for the Great Eastern, and weiglis eight tons exclusive of the stock. Its dimensions are : Length of shank, twenty feet si.K inches ; of wooj-stock, nineteen feet si.K inches ; trend of arms, seven feet fonr inches. It is somewhat ditferent in form from ordi- nary anchors, the palms or blades being divided or split so that it may more readily pierce the sea- bottom. Tlie parts of an anchor are as follows ; — a to b, shank ; b to c, square ; o! to e, arm ; / to g, palm, fluke, or kevel ; h to i, point, pee, or bill ; Fii;. 191. til u 1 to I; blade ; M to iV, crown ; o, ring ; p, stock ; d, tlnoat or crutch. For clu'cking and regulating the motion of the cable as it runs towards the hnime-holcs wliile the anchor is droiiping, und for holding the cable after the anchor lias taken hold, four kinds of apparatus are used to'jetlier or sei)arately, — Con'ti'.olleiis, BiTT.s, STciriT.ns, Cumphessous (which see). To cad or drop anchor is to let go the anchor. To ride at anchor is the condition of the vessel when anchored. To sieinij at anchor is when the ship obeys the change in the direction of the tide while at anchor. To iveirjli anchor is to heave it out of the grounil. To back an anchor is to strengthen its lioUl of the ground by means of a seconil anchor laid down ahead of tile other, and fastened to the crow'n of tlie latter by a cable. An anchor is foul when the cable is twisted around it or the anchor is entangled with a wreck or another anchor. The anchor bites when the fluke takes hold of the gi'ound. To sirei-p for an anchor is for the recovery of a lost anchor by sweeping the bottom with the bight of a cabh' or haw,ser. Pnrliiuj : Breaking cable and leaving the anchor in the ground. An anchor is a-cock-bill when it is suspended per- pendicularly from the cathead ready to let go. It comes home when dragged from its hold by the pulling of tlie cable. An auchor is a-stay when the angle of the cable with the water is about that of a stay. A long-stay apeak when coinciding with the main stay ; sliort stay wlien with the /ore stay. It is a-pen/c when the cable is drawn in so tight as to bring the ship directly over it. It is a-weigh, or a-trip, when lifted clear of the ground. It is a-wash when lifted to the surface of the water. It is hove up when lifted to the hawse-liole. It is Iwokcd when cat-fall is fast to the ring. It is catted or lumled up when lifted by tlie ring to the cathead. It is f shed when the fluke next to the ship's side is lifted to the iish-davit. It is OH-board when the fluke is lifted to its rest- ing-place on the bill-board. It is in-board when on deck. It is secured when all is made fast, the cable and buoy-rope unbent, and the anchor stowed. The weight of Anchor and Kedge is given exclu- sive of that of its stock. Bower and Sheet Anchors should be alike in weight. Stream Audwrs should be \ the weight of the best bower. Kedges are light anchors used in wai'jiing. 2. The block, frame, or masonry deeply buiied in tlie earth, to which the cables or wires of suspen- sion-bridges are attached. See Anx'HOH, Suspen- SIOX-C.AHI.E. An'chor and Collar. A form of hinge foi' a lock-gate. The anchor is let into the stone coping ; the collar is attached like a clevis to the anchor, and forms a socket for the pintle of the heel-post of the gate. An'chor-balL 1. A contrivance of Captain Manby, li. N., for saving life in eases of shipwreck. It is a ball having several hinged prongs fitting in slots, which are intended to catch in the i-iggiiijj of a stranded vessel. It is tired from a mortar, and carries a light lim by which a stout rope may be carried ashore froui the ve.s.sel. The French use a ball for this purpose having i harpoon passing through it, on the rear end ol which a line is wound. 2. A carcass or incendiary ball aflixed to a grapnel by which it is intentled to adhere to and hre a vessid. An'chor-bolt (Machinery. ) One having an expanded sliaiik to prevent its drawing out. An'chor-chocks. Blocks on which a starved anchor r '.sts. An'chor, Sua-pen'sion-ca'ble. The anchors of Fig. 192. Suxpfn$i on- Chain Anchor. ANCHOR-DRAG. 97 ANCHOR-TRIPPER. the chains of the Meiiai Suspension Bridge are cast- iron plates liaving a bearing against tile soliJ rock. Three obliijue circnlar shafts six feet in diameter and sixty feet in depth were blasted into the solitl rock, a considerable space being left between each shaft. At the bottom is a cross-tunnel which runs horizontally and at right angles to the inclined shafts. The iron plates, weighing 2,240 pounds, were fitted into seats in the face of the rock at right angles to the chains which are bolted thereto, a, cross-tunnel ; b, anchor ; c, suspension-cable. An'chor-drag. See DnAO-ANXHOR. Au'chor Es-cape'ment. The anchor escape- ment superseded the crown-wheel escapement for clocks. It was invented by Clement, a London watchmaker, in 16S0. By some it is credited to Dr. Hooke. The anchor has two arms whose hent ends resem- ble Hukes in some degree, and thus give rise to the name. It is suspended from a horizontal axis, on which it turns freely along with the dejieudent stem, which terminates at its lower end in a fork or crutch between whose prongs the pendulum-rod passes, so that the motions of the pendulum are communicated to the anchor, and the pressure of the wheel upon the pallets of the anchor is also communicated to tlie pendulum so as to make up for the .small loss by friction incident to its action. "The great advant.age of this escapement over the ohl crown-wheel is that it allows the escape to take place at a small angle of vibration, thereby preventing the necessity for the maintaining power acting upon the pendulum with so gi'eat foi'ce as by the old plan ; and by the introduction of a heavy ball, leaving that to be done by the uniform power of gravity which before was dependent upon the impulse given by the wheel to the pallets." Clement, in connection with this escapement, introduced his mode of suspending the pendulum by a thin piece of llexible spriug, a mode which has remained in favor ever since. Fig. 193. Recoil. Anchor Escapement. Figure 193 shows two foi-ms of anchor escapement : one is on the recoil principle and the other is the ckad-lmt ; the former is so called because each tooth of the wheel makes a back or recoil motion after escaping from the pallet. In the figure one tooth is represented as having just escaped from the anchor, and a tooth on the opposite side of the wheel has dropped on to the pallet. The pendu- lum continuing its course a little farther to the left. I the slope of the pallet will drive the tooth on the right a little way back and produce the recoil. The other figure shows the (lead-beat escapement, in which the slope of each jiallet stops at the points where the teeth fall, the rest of each pallet form- ing portions of a circle of which the axis is the center. The tooth having passed the pallet, the continued motion of the ijendiiluni merely holds the tooth, but does not give it any backward mo- tion. See Dead-beat Escapement; Recoil Escapement. An'ohor-gate. A heavy gate, such as is used in the locks of canals, reipiires for its upper bearing a collar which is stayed by the adjacent masonry. Barbed metallic projections from the collar are em- bedded in the masonrj', and resist displacement of the gate while enduring strain or swinging on its axis. An'chor-lin'ing. Sheathing on the ship's plank- ing, under the fore-channels, to keep the bill of the anchor from ripping the ship's side when hauling it up, or fishing. An'chor, Mush'room. The vmshromn ancJwr is used for moorings, and is said to be a favorite in the East Indies. Its name indicates its form, hav- Fig. 194. Mushroom Anchor, ing a central shank and a head of a howl sluape, which reijuires no stock on the shnvk to cause it to engage with the ground over which it is dragged. An'chor-ring. The ring of an anchor by which it is bent to the cable. A jew's-harp shackle is now used. An'chor-stock Plank'ing. (Sliip-building.) Each ]ilank has one straight edge, the other consist- ing of t\\o equal slopes. An'chor-trip'pers. These aredevices for "trip- ping " or casting loose a shiji's anchor. In some of them it is suspended by its ring from the cat-block or a tripjnng-bolt ; in others it is fastened at each end liy chains which are cast loose simultaneously. DuN(.-AX, April 2 8, Fig. 195. 1863. The anchor hangs ^ „„,„„. M>i.„--. from a clutch-ring on the ^ cat-block, which is sus- pended below the cat- head. AVhen the fall is east loose, the block de- scends, and the clutch is opened by the chains which are attached to the cathead, and to the pro- jecting levers or prongs on the respective halves of the clutch. A .single mo- tion, the slackening of the fall, operates the trip- per ; the clutch is opened when the chains are made taut by the descent of the block. Stacey, December 27, 1864. The anchor is suspended by its ring from Duncan^ s Anchor- Tripper. ANCHOR-TRIPPER. 98 ANCHOR-TRIPPER. Stacey's Anchor-Tripper. the hook of the fall- block, which depends fi-om the cat-head. The tripping-roiie is attached to an eye on the fall-block hook, and is belayed to a pin on the cat-head. When the fall is cast loose, and as soon as the slack of the triiiping-rope is e.Khausted, the said rope upsets the hook, and casts loose the anchor. Holmes, April 28, 1857. A short chain is attached to the ring of the anchor, and the link on its upper end is trausti.\ed by a pin which has its bearings in a block. By turn- ing the handle half a revolution in one direction, the screw upon the shaft will cause the pin to recede, and disen- gage itself from the link of the cliain. The thread works in a sjiiral groove or nut, by which it receives lon- gitudinal motion \vhen partially rotated. Heit.man, May 16, 180.5. The anchor is sus- pen clasp c, and hold it closed while the pin /( is withdrawn, and the hasp (l is cast otf. The linnd- sjiike being then removed, the oblique end c of the bolt throws open the clamp c, and the bolt revolving on its pivot d allows the standing end of the cat- head stopper to fall off, and the anchor to drop. Spence's tripper (English) is especially intended for casting off the sluinlc-painter , which holds the Fig. 201. Spencers Anchor- Tripper. shrink and flul~es to the ship's side, while the cat- head stopper holds the rincf of the stocJc. a is a carriage bolted to the gunwale ; i is a liolt which is pivoted at i to the carriage, and sustains the chain-end of the .'ilmnk-paintcr ; e is a lever pivoted at /to the upper side of the carriage a, and iiaving a hook d at its end which holds the bolt b in an upright position. When the shanl' -painter is to be cast oil', a pry is taken upon the end of the lever by a haiulspike till the pin (j is removed. The ANCHYLOSIS APPARATUS. 99 ANEMOMETER. lever e is then oscillated till the hook d is disen- gaged from the bolt b. Tlie latter is immediately rotated by tlie weight of the anchor, and the shank- painter is east loose. Anch'y-lo'sis Ap'pa-ra'tus. Anapjiaratusforre- lieving the strain Fig. 202. Anchylosis Apparatus. upon the tle.xed anchylosis articu- lation by support- ing the respective parts of the limb at a distance from the center of lev- erage. Fig. 202 shows an apparatus adapted for the knee. The upper and lower bands are secured around the thi^h and low- er legrcspectively, J^the joint being set immovably at the angle reijuired. The small tigure represents the key by which the joint is loosened or locked. Aucon ; An- cone. An elbow or angle. Aquoin. console. An ornamental keystone. A Tlie an,t,'le of a knee-tumbler. An'co-ny. ( Mela I- workinfi. ) A piece of partially wronglit bar-iron, partly finished in the middle, but unwrought at the ends. An'cove. (Architectnrc.) A console on each side ol a duor to support a cornice or entablature. An-cy'lo-mele. A curved probe used by sur- geons. And'i-rons. Tlie.se are used upon the hearth to support the burning logs and brands. Sometimes called dog-irons, and familiar to all who have been aciiiiainted with the old-fashioned fireplace. Smvlir, .Inly 12, lSi3. The horses of the andi- rons are adjustably connected, so as to place them ftt any convenient distance apart and keep them steady. They are guarded by a safety-bar against the danger of upsetting. LoG.VN', March 27, 1S60, has a bottom plate or frame, in combination with two upright angular bars, in such a manner ^^^ Fig. 203. that the same stands ipi\ firmly in its place and allows a free circulation of the heat. The name andiron is supposed to be derived from the Anglo-Sa.xon ,brand-iroH. Others de- ^^■'rive it from hand-iron. For the large kitchen fire, the andirons were Logan's Andiron. very strong and massive, but usually i[uite plain. In the hall, that ancient seat of hosjiitality, they were also strong and massive, to support the weight of the huge logs ; but the standards were kejit bright or ornamented with brass rings, knobs, rosettes, heads and feet of animals, and various grotesque forms. In kitclnns, and in the rooms of common houses, the andiron, as its name implies, was of iron ; but in the hall the standards were of copper or brass, and sometimes of silver. Until the seventeenth century wood was the ordi- nary fuel. It was burned in holes dug iii the floor, on hearths in the middle of the fioor or against the Fig. 204. wall. Chimneys are a comparatively modern inven- tion, and no traces of them are found [irevious to the twelfth century. See Chimxkv. In the baronial halls of England the logs were liberally piled on the hearth in the middle of the hall, being confined within the two staiulards of the andiron, their ends resting on the billet-bar for the purpose of admitting air beneath them, and thus promoting combustion. A-nem'o-graph. An instrument for measuring and recording the direction and force of the wind. An'e-mom'e-ter. An instrument for detennining the foue of the wind. The most simple fressui'e, invented by M.A^idi of France. The action of the aneroid depends on the pressure of the atmos]ihere on a circular metallic box hermetically sealed and having a slightly elastic top, the vacuum serving the ])urpose of the colunm of mi^i'cury in the ordinary barometer. The arrangement is illustrated by the accompany- ing figures, the first showing the face and the second the interior of the instrument, which is made about 4J inches in diameter across the face and IJ inches thick. The pressure of the atmosphere is shown by the liand pointing to a scale which is graduated with 40 divisions to the inch ; one or two thermometers are aftixed to the face, but are not essential. The sei>ond figure shows the internal construc- tion, as seen with the face removed, but with the hand still attached. « is a flat, circular me- tallic box, about 2j inches in diameter and J of an inch dee]), having its upper and lower surfaces corrugated in concentric circles. This box or chamber, being exhausted of air through the short tube b, which i.s subsequently made air-tight by soldeiing, constitutes a spring which is aftected by every variation of pressure in the external at- mosphere, the corrugations increasing its elasticity. At the center of the u)iper surface of tlie exhausted chamber is a solid cylindrical projection x, about half an inch high, to the top of which the principal lever c d e is attached. This lever rests partly on a spiral spring at d ; it is also supported by two vertical pins with per- fect freedom of motion. The end e of the large or Fig. 210. Aneroid. principal lever is attached to a second or small lever f, from which a chain 7 extends to h, where it works on a drum attached to the arbor or axis of the hand, connected with a hair-spring at /(, changing the motion from vertical to horizontal, and regulating the hand, the attachments of which are made to the metallic plate i. The motion origi- nates in the corrugated metallic box n, the surface of which is depressed or elevated as the weight of the atmosphere is increased or diminished, and this motion is comnmnicated through the levers to the axis of the hand at h. The spiral spring on which the lever rests at d is intended to comi>ensate for the etfects of alterations of temperature. The actual movement at the center of the exhausted box from whence the indications emanate is very slight, but by the action of the levers this is multijdied 657 times at the point of the hand, so that the move- ■5^X1 through three inches on the dial. Barometeh. Fig. 211. See also BounDo Aneurism Needles. An'eu-rism Nee'dle. A needle for passing a ligature around a dilated artery. An'eu-rism Tour'ni-quet. An instrument for briui'iug a pressure ujiou a sanguineous tumor re- sulting from the dilation or rupture of the coats of an artery. The instrument lias two legs and a hinge-joint. The pressure being adjusted as required, the hinge is set by the key so as to make it rigid. An'gar-i-po'la. {Fabric.) A kind of coarse linen nuide in Spain. An'ge-lot. A nuisieal instrument of the lute kind. An'gel-shot. See Chain-.shot. An'gle. The arris or edge, salient or receding, formed by the junction of two surfaces not in the ANGLE-BAR. 103 ANGLE-IRON. Jig. 2:12. Aneurism Tourniquet. same plane. Various are the modes of attacliing the two portions ; among other devices may be cited : — Angle-joint. Feather. Rebate. Cramp. Glue. Serews. Dovetail. Miter. Tongue and groove Dowel. Nails. See JoiN'T. Pieces at the angles of structures are known as — Angle-brackets, angle-rafters, angle-ribs, angle- bars, angle-staffs, angle-tie, etc. An'gle-bar. (Carpentiij.) The upright bar at the meeting of two faces of a polygonal or bow window. An'gle-bead. A strip having a rounded edge, and placed at the vertical exterior angle formed by plastered surfaces. A beaded-edge angle-statf. An'gle-brace. A corner-drill. An angle-tie. An'gle-brack'et. (Curpcntnj.) One beneath the eave at tile corner of a building, and projecting at an angle of 45' with the face of each wall. An'gle-float. A float made to fit any internal angle of the walls of a room. A float is a plasterer's trowel. An'gle-gage. A gage for setting the reflectors on a frame for the e.\hibition of light under the catoptric system, has two long arms connected by a gi'aduated arc. The arms, having been first placeil at the angle whi-h is supplemental to that of the inclination of the axes of the two adjacent mirrors, are made to span the faces of the reflectors, one of which is moved about till its edges are in close contact with the flat surface of one of the arms of the gage. The instrument has many other applications. A gage for determining angles of hexagonal nuts. The graduated bar A has graduated arms B and (J ; Fig. 213. An'gle-i'ron. {Machinery.) A bent piece joining the sides of an iron structure. See Aniu.e-joint. A description of iron which is used for ship's knees, for uniting the edges of plates which meet at an angle, and for other purposes too numerous to mention. On a larger scale, with more than one bend, it may form a beam, girder, or rail, the differ- ence consisting rather in proportions and purjiose tlian in construction. The fagoting and construc- tion of wrought-iron beams will be considered under Beam, Wrought- ikox. Some devices substan- tially similar in inventive features will be found under Rail!10.\d-rails, Fagoting, and Rolling; the difference between a railroad-rail and a girder is one of shape and proportion of the parts, as will be seen by comparing their cross-sections. Lewis, Aprif 26, 18t)4. The rollers have fiat faces, and a central triangular gi'oove, and rib re- spectively, so that the bar can be introduced between the rollei-s flat, instead of cornerwise. The efl'ect of this is, that both sides of the angle-iron when finished run parallel to the layers of the original bar. and not crosswi.se, as is the case with Fig. 2U. i" I ' r; I ' 7 ^T=^ I.. I ^ ! . ' -i . i -. ^^g ' ^ I Eeltogg's Angle- Gage. the latter movable, and proWded with a block whose edge fonns with it an angle of 120° as a gage for hexagonal prisms. Lewis's Machine for Hotting Angte-lron. one side of the angle-iron when rolled in the ordi- nary manner. The parallelism of the wings with the top of the pile is maintained till the bar is reduced nearly to its proper tliickness, when it is finished by passing it through a plain rectangular gi-oove which turns up the wings and finishes them with a grain conformable to that of the original bar. The ordinary angle-iron is a bar whose section Fig. 215. ^^ Angle-Irons. forms two sides of a triangle, but the term now includes other shapes, such as the cruciform, etc. a is an angle-iron forming two sides of a right- angled triangle ; b is a flatter form Fig. 216. with two flanges, and is called "chan- nel-iroii " ; c is cru- cifomi in cross-sec- tion. It is called *' cross half-lattice iroii," Box- Girder and T- Iron. r '^t' I L . . '^ ANGLE-IRON. 104 ANGLE-IRON. d, Fig. 216, sliows the application of angle-iron in making a bo.x-girJer, or wrouglit-iron cell ; c is a form having a Iraid and web. It is called T-iron. Other forms are known as Z-iron, I-iron, etc. Fig. 217 shows the mode of using angle-iron in compound girders, tanks, and other structures. / shows its application to uniting the angular junction of two plates. ¥ig. 217. An^le-lrons. g shows a beam strengthened by angle-plates at each side. h shows angle-plates uniting a tread-plate and its web. Angle-bars for shipbuilding are bent and worked into the various forms required in ships, by men called angle-iron smiths ; they are then pnnc.'licd with holes, generally about the center of the arm, and by the rivets inserted in these holes the angle- iron is attached to the plates of the ship. The dimensions are usually given in the specification of Fig. 218. Arxi^lt- Irons for Shipbuilding. a vessel in this form, namely, 3 in. x 3 in. x J in. This means that each arm of the bar is to be three inches from the angle, and the thickness in the center of arm, or at the rivet-hole, half an inch. As angle-iron is generally applied for the ribs of a ship, the arm which is perpendicular to the sur- face of the plates is that which is in the position to afford the gi'eatest stifiness to the shell. On this account angle-iron has been rolled with arms of unequal lengths, that the greatest strength may be obtained from a given quantity of iron. a, 6, c, d, are angle-irons and braces for flooring in iron ships. e shows the connection of outer skin and inner flooring by angle-irons. / is the arrangement of angle-irons and braces for stiftening ship's bottom longitudinally ; answer- ing to the keelson in wooden vessels. cj, keel ; showing its connection to the outer skin and beams. Angle- Irons for Shipbuilding. CI, h, c, d, e, /, are angle-irons and beams employed for flooring in iron ships. (/, outer skin and flooring of an iron steamer with- out keel ; showing the mode of connection of the two, and the longitudiiuil stiffening-plates and angle-irons of ship's bottom and flooring. The angle-iron and plates for building iron ships are heated in reverberatory furnaces, of which two are generally placed together, the flues from them leading to one cliimney. They are formed of brick and have a brick turned arcli, the sides being se- cured by binding-pl.alrs, like a puddl intj-furnace. One furnace is made wide, say 4i x 10 feet, and is suitable for heating plates ; the other long and nar- row, say 2 feet wide by 25 feet long, and is used for heating the angle-bars which go to make the frame. An iron sill is placed across the doorway on which the angle-iron slides in entering or withdrawing. The furnace A has the usual grate-bars, and a pan B beneath, filled with water, cools the ashes as they fall and thus preserves the bars from injury. This furnace is fed with coals, the flame of wliich passes along the chamber C, and over the brick bed D, on which the plates or bars are laid. The roof over the whole is a brick arch, about two feet from the bed, acting by reverberation, to concentrate the ANGLE-JOINT. 105 ANGULAR IRON-BAND. heat upon the iron. The flame and hot air then escape down a narrow flue, situated across the mouth of tlie furnace, and leading by the main flue to the chimney. The end at which the plates or hars are inserted and withdrawn is closed by a door F, framed of iron, and enclosing flre-bricks. This, being very heavy, is suspended by a chain, and this chain is attached to a lever G, having a balance-weight H suspended from it, that the men may have less dilficulty in raising and lowering it. Fig. 220. Angle-Iron Furnace, Angle-joint. Angle- joints differ according to the material, thickness, purjjose, and e.vposure. a, b, are joints which are Fig. 221. entirely dependent upon sol- der ; such are used with tin- ware and sheet-lead. c is a 7nikr-joint. It is used for thicker metals with hard solders. d is a butt-joint; other- wise similar to c. e is a lap-joint ; the metal is creased over the hntchet- stakc or by the spinning-tool. It requires solder. /, one plate is bent rec- tangularly, and the other is doubly bent so as to recurve back on itself, lappingctrow^rf the edge of the other. It needs solder to keep it from slipping apart. g has a fold to each plate ; these lock upon each other and require no solder to per- fect their hold, although it may be added to make the joint air and water tight where the closure is not ab- solutely perfect. h is a riveted joint, one plate being bent to lap upon the other. This joint is called the folded angle, and is common in all sizes of work, from domestic uten- sils to steam-boilers. i, the edge of one plate is formed into tenons which Angle-joints. enter mortises in the other, and are there riveted. j resembling i, except that the tenons are pro- longed, so as to be retained in the mortises by cotters. k; one plate makes a butt-joint with the other, and is attached by L-formcd rivets or screw-bolts, whose heads are riveted to one plate, while their screw-stems pass through the other plate and are fastened by nuts. 1, the two plates are secured by being bolted or riveted to an angle-iron, which is straight or bent into sweeps according to the shape of the object. An'gle-me'ter. Any instrument for measuring angles. The term seems to have become more par- ticularly ajiplied to an instrament made use of by geologists for ascertaining the dip of inclined strata. In the broader sense of a measurer of angles it would include a great number of astronomical and surveying instruments for measiiring angles, such as transit instruments, quadrants, se.xtants, theodo- lites, adapted for observations in altitude and azi- muth ; also those of special adaptation, as angu- lometers, goniometers, protractors, etc., which are treated under their h respective heads. rr An'gle of Re- pose'. {C'icil Eiuji- nccring.) 1. The ut- most inclination at which a carriage will stand at rest upon a road. At the an- of repose, the gi'avity of the load and the friction of the load are equal. See FniCTloN. 2. The natural angle at which the soil of a cut- ting or embankment will stand without slipping. See Si.ijpE. An'gle of Sight (Ordnance.) The natural angle of sight is the angle between a line drawn through the axis of the bore, and a line drawn from the rear of the base-ring to the swell of the muzzle or to the top of the sight. An'gle-plane. A plane whose bit reaches into a re-entering angle. An'gle-raft'er. {Carpentry. ) A rafter at the hip of a roof, receiving tlie heads of the jack-rafters or cripplc-stndiUng. An'gle-staff. A strip of wood fixed to the ver- tical angle of a wall flush with the plastering of the two planes. It is designed as a substitute for plas- tering in a situation so nnieh exposed. A round staff is known as an angle-bead. An'gle— tie. (Carpentry.) A brace-jnece in the interior angle of a wooden frame, securing two side- pieces togetlu'r and occupying thereto the position of a hypothenuse. An-go'ra. (Fabric.) A light and fashionable cloth made from the wool of the Angora goat. An'gu-lar File. A locksmith's file for working into the corners of the wards in keys. An'gu-lar Gear'ing. The wheels are quadri- lateral, and the speed of the driven wheel is variable. The driving-wheel, ro- tating at regular speed, will impart a quicker rate to the other wheel when the angle of the former is in contact with the flat side of the lat- ter, and conversely. Has been used in printing- presses. An'gu-lar In'stru- ments. {Surveying.) One in which the horizontal angles are measured by a divided circle and verni- ers as well as by the needle ; as the superior kinds of railroad comiiasses, the engineer's and surveyor's transits, etc. An'gu-lar I'ron-band. A ferrule angular in its Fig. 222. ANGULAR THREAD. 106 ANIMAL POWER. cross-section. A sipiare, or other sideil collar or biinlin'.^-lion[i. An'gu-lar Thread. A screw-thread whose pro- jeotion lieyoiid the barrel of the screw is triangular in cross-section. In contradistinction to a square thread. An-gu-lom'e-ter. This instrument is defined by Francis as one for measuring exterior angles. The tenns angle-meter and goniometer might be held to mean tlie same thing judging by their derivation, but the former is ajiplied to instruments u.sed by geologists for mea.suring the dip of strata, and the latter for measuring the angles of crystals. A try-s(iuare may be termed an angidometer, " a bent nu'a.sure." Thayeii, August 26, 1862. This invention consists in so construct- FiR. 223. ing and hang- ing a pendulum, and connecting it with a portion of the surface of a sphere, that it will indicate at once whetlier any plane to which it is ap- plied is level ; and if not so, will sliow the degrees of the angle, whether of elevation or de- pression, which such plane makes with the horizon. The jiendulum moves u])on three or more bearings in the same plane, and carries upon its top a graduated ar Thayer^s Plane An^&meter. Fig. 224. acting ni com- bination with the spherical surface and the opening there- Hali.'s angu- lometer has two hinged legs, and a graduated arc wliich indicates the dihedral angle. An instrument called a enrlrmis, for measuring the angle for the facets of gems in cutting and polishing. Fig. 225. HnlVs An^ulomftfT. Genevese An^ilometer. The gem i^ cemented on the end of a rod which is clamped between the jaws a, which are closed like a vise by means of a set-screw passing through them. Each of the jaws has on tlie inside a hemi- spherical cavity into wliich is fitted a brass ball. A tube passes tliiough the ball, and carries at its ■upper end a small graduated disk. The cement- stick, carrying the stone to be cut, fits within the tube sufficiently tight to hold it while Fig 226 a facet is being cut, and the upper end of the stick has a pointer by which the divis- ions on the disk are read off. The vertical angle of the tube is deter- mined by the (luadrant c, fixed on one side of the jaws a, and the tube is retained at any angle by closing the jaws upon tlie ball. The divisions of the quadrant admit cf any degi'ce of vertical inclination upon the s/civc, or of "^ vertical position when grinding the table or collet. The facets around the .stone will be deter- mined by twisting the cement-stick in the tube, until the index marks the required division on the disk b. An'i-mal Black. Carbonaceous Fig. 227. matter obtained by the calcination of (f\ bones in close vessels. Used in filtering, y,ii^ deodorizing, defecating, discoloring syr- ^jS^I ijl ups, liquors, solutions. ( ^j An'i-mal Cbar'coal. Calcined bones preiiared for sugar-refining. See BoNE- BL.vcK rrnx-\CE. An'i-mal Clutch. Agrippingdevice for catching animals by the leg. It is especially used for slinging animals dur- ing the operations of slaughtering. In the noose form. Fig. 226, the cliain is attached to one end of the plate, and the key on the end of the chain engages in the slot to form a bight for looping around the leg of the animal. In another i'onn. Fig. 227, thegambrel of theanimalis clutched by tlie gripping- jaws which are attached by cliains to the frame, whose roller travels on a way-rod to transport the hog from tlie "sticker" to the scalding-tub, or from the latter to the "gutter." An'i-mal'cule Cage. A cell in whicli living microscopic objects are Hog-Hoister. kept and exposed to view. An'i-mal-iz'ing Fi'ber. The process of confer- ring upon vegetable fiber tile phj'sical characteristics of animal fiber. Cotton, under the microscope, is a riblion-shaped tube, and when treated with a cold, strong solution of caustic soda, shrinks and assumes the form of a simple cylinder. It becomes stronger, smaller, and has an increased capacity for receiving coloring matter. An'i-mal Poke. A yoke placed upon an animal to keep it from pushing down or jumping fences. See Poke. An'i-mal Pow'er. The expression of tlie nu- merical values of the results of the labor of men and animals, particularly horses, is a subject whicli on account of its eminently practical bearing has at- tracted considerable attention among scientific as well as practical men. A work entitled " De Motu Anamalium " was pub- lished as far back as 1680 by Borelli, but Coulomb, who devoted a great deal of attention to the matter, has furnished more information of jiractical value than any other writer. The unit of value employed by Coulomb was 1 kilogramme (2.2047 pounds) trans]iorted a distance of one kilometre (6.214 miles) the total force exerted being estimated by the number of kilogrammes of the burden multiplied by the number of kilometres it is trans])orted during a working day of eight hours ; these measures are of course ri'adily reducible to any other denominations, as pounds and miles. Coulomb ascertained that on an average a man ANIMAL POWER. 107 ANIMAL TRAP. could travel unloailod 31 iniles jtcr day ; and sup- posing his weight to be 160 lbs., the e.xpression for the ctfect e.xerted by him would in this ease be 160x31 = 4,960 pounds carried one mile per day. He found also, by the average of the work performed by tlie portei-s of Paris, that a man could carry a burden equal to 12S lljs. 9.72 miles per day. As- suming the weight of the man to be 160 lbs., the total effect produced would be eipiivalent to 160-1- 128 X 9.72=2,799 ; but the transportation of his own weiglit formed no part of the useful effect, wliich is con.sequently exjiressed by 128 x 9.72=1,244. The u.seful effect is found to be at a ma.ximum when a man is loaded with 121 pounds ; under this burden he can walk lOJ miles per day, giving an effect of 121 X 10^=1,250. A porter going short distances with a burden and returning unloaded, as usually occui's, carries 135 lbs. 7 miles per day. A man can wheel 150 lbs. in a wheelbarrow 10 miles in the same time. The maximmn effect of a strong man exerted for 2i minutes is estimated at 18,000 pounds raised one foot in a minute ; and the force of a man of ordinaiy strength exerted in lifting is equivalent to 30 lbs. I'aised 2A feet per second for ten hours, or 4,500 lbs. raised 1 foot per minute ; the estimated power of a horse being equivalent to 33, 000 pounds raised one foot in the same time, according to Boultou and Watt's experiments. The following statement by Hachette shows the force exerted by the strength of men applied in ■various ways, expressed in terms equivalent to the number of pounds carried by a man one mile during a day of eight hours. brawing a light four-wheeled wagon over moderately uneven gi'otind . . 857 lbs. Pulling hoiizontally at a rope attached to a weight and passing through a pulley 378 " Rowing in a boat . . . . . 374 " Pushing horizontally, as at a capstan . 368 " Turning a winch and axle . . . 159 " The above estimates are based on the average strength of men generally, and in many instances, es])ecially in carrying weights, are largely exceeded ; thus it is said that a London porter will carry 200 lbs. on his shoulders at tlie rate of three miles an hour, but such efforts cannot be sustained for any great length of time. The porters of Constanti- nople are said, by a judicious distribution of their burdens, to carry much greater weights than this for considerable distances. The useful effect of a horse walking in a circle, as in turning a mill, is es- timated at 800 lbs. A horse carrying a load of 200 lbs. 25 miles per day ..... 5,000 " An African dromedary carrying his rider (160 lbs.) can travel for 9 or 10 hours at the rate of between 7 and 8 miles per hour ; say 160 x 9J x7J= 11,400" An Asiatic camel can carry a load of from 500 to 800 lbs. at the rate of 2J hours ; this for a day of 8 hours would give (assuming the load to be 600 lbs.) 600x8x21 or . . 12,000" A draft-horse can draw 1,600 lbs. 23 miles per day, the weight of the carriage being included. In hauling for short distances and returning unloaded, a horse will draw on a good road 2,000 lbs. or more, exclusive of the weight of the cart. In drawing a load the greatest effect is found to be produced when the traces are perpendicular to the collar ; as the position of the horse changes in heavy pulling, the traces become moie nearly parallel to the road. With very hea%'y drafts, loading tlie back of a horse is found rather advantageous than otherwise, by not compelling him to incline forwaid so much and enabling him to use his muscles in a more advantageous position. The circle in which a horee moves in turning a mill sliould not be less than 25 or 30 feet ; 40 feet is better. According to Tredgold, a horse can draw, as indi- cated by the dynamometer, 125 pounds at the rate of 2i miles per hour, which for one day will give 125 x 2j X 8=2,500. By the experiments of Boulton and Watt they determined that a good horse can draw 125 pounds at the rate of 3 miles per hour, 125 x 3 x 8=3,000 pounds one mile in a day. Multiply this amount by the nundier of feet in a mile, and divide the product by the number of minutes in 8 hours ; the result is 33,000, which stands for the number of pounds raised one foot per minute, and this is now the admitted measure of a horse power. An'i-mals. In the nomenclature of the mechanic arts, the names of animals have not been entirely overlooked e. g. : — Ass. Cricket. Hound. Rat. Bear. Crow. Jack. Seal. Bee. Dog. Jenny. Serpent. Beet'e. Dolphin. Kite. Skate. Buck. Drill. Leech. Slug. Buffalo. Fish. Lizard. Snail. Bull-dog. Fly. Mole. Sole. Butterfly. Fox. Monkey. Starling. Camel. Frog. Mouse. Swift. Cat. Goose. Mule. Throstle. Cock. Hawk. Pig- Turtle. Cow. Hedgehog. Pike. Urchin. Crab. Hog. Ram. AVorm. Crane. Horse. Each of these useful animals is described in its alphabetical place. An'i-mal Trap. A device for catching anima's. There are numerous varieties ; some to set in the' path of the animals, others are pulled off by a per- son on watch ; tlie more common forms are those in which the animal is the cause of his own capture by meddling with the bait, or by crawling into his prison in search of food. A few instances of different arrangements will be given. 1. The (jitUlotine-trnp has a descending knife or row of spikes which descends vertically upon the animal which is tampering with the bait. 2. The rotnting-claw is actuated by a spring on the axis, and is released by nibbling at the bait. It strikes the animal, and throws him to a distance, resetting itself. 3. The dead-fall is a weight or sjmng bar, re- leased by the animal, either by stepping on a plat- form or touch- ing the bait. Fig. 228. 4. The grip- ^ ' "iP ^"^ pimi- jaw -trap ^ ' is shown in the familiar form wherein the jaws are actu- ated by a spring released by the depres- sion of a small platform be- tween them. -rLfe^ Auotherform— _=5" of jaw-trap is S^nj Jaw-Trap. ANIMAL TRAP. 108 ANIMAL TRAP. seen in Fig. 22S, in which the spring and jaws are made of one strip of steel, and tlie brace, which keeps tliem apart, has tlie bait attached ; a trigger releases the jaws, which gi'asp the animal that is pulling upon the bait. The illustration shows Fig. 229. the mode of setting the trap. The forward part stands on two legs, and the bow at the rear is sup- ported on a little crotch. 5. Thefallinij-cage. This may be a wire basket, as in "Fig. 229. The bell- shaped cage is suspended vertically above the plat- form ; it rests upon a tog- gle-jointed bar, and is eleased by the baited 1 trigger, which allows the toggle to double up. Another fonu of drojiper A disk with a circular Trap. is shown in Fig. series of vertical 230. wires. The arm which rises ver- tically from the falling disk has at top a staple which rests on the top of a vibrata- ble lever, to which the bait is tied. The fall of the disk im- prisons or impales the ani- mal. 6. The gravitatinii-plal- form has many forms. Fig. 231 may be taken as an illustration. Pressure on the swinging bait-bo.x releases the plat- form, which swings and pre- cipitates the animal into the cage beneath. The ad- justable weight returns the platform to place, when it becomes reset. nl I fflilTillil'HJ'li'lllil'ill '"'''^ essential features of lllllllll 'IIImHI I these traps are a falling platform, a resetting de- vice, and a receiver beneath. The resetting is sometimes done by a spring, some- times by a weight, in some cases by the animal in passing to an interior cham- ber. Fig. 231. Dropping- Ca^e Trap. an Failing- Platform Trap. 7. The rotatinff-plnt/orm, Fig. 232, has a number of platforms brought successively into use. A series of wings is attached to a rotarj'-shaft that is actuated by a weighted cord, so that they consecutively assume a horizontal position, fonning a platform upon which the rat stands while nibbling at the bait, Fig. 232. and from which he is thrown down into the trap. In anoth- er form, the wheel is ro- tated by a coiled spring, the radial wings being in turn de- tained by their latches, wliicli catcll upon a detent-lug on the case. The motion of the oscillating platfonn disengages the latch, the wing descends, and the ne.xt becomes ready for duty. Fig. 233 has a duplication of the rotary feature. The invention consists of two radial ro- tatiug-platforms, each held in position by separate triggers, but the wires controlling them come to- gether at the bait-hook, which forms one of them. Fig. 233. f- .■ " ^^'.^"."i' w.'. ■ 1 : 1 1 ■i ■ ' .... ^ ■^i^^^^— j3 ' 1 1 " ' ' 1 t Rotary-Platform Trap, GatcheWs Trap. Each wire is connected with a rock-shaft, and the triggers or detents are withdrawn by the pulling of the bait by the animal, whose resting-]ilace is at the center, upon two wings. Upon the animal falling into a receptacle below, the trap is reset. 8. The fallincj-door. Several forms of traps which come under this class are familiar to the public, some with one door, and some with two. Fig. 234. -•^7" - I Falling- Door Trap. ANIMAL TRAP. 109 ANKLETS. Fig. 234 is open at both ends, when set, the doors B being supported by triggers. The animal stand- ing on the platform (?, to reach the bait on the hook, operates the rods /, C, and releases the doors, which fall .simultaneously. This darkens the trap, and the animal lifts the grating in passing to the light chamber M. The opening of the giating resets the trap. 9. A slidhig-gatc. Of these there are several varieties. In Fig. 235 the animal passes through one of the holes into the first chamber. His weight Fig. 235. Sliding- Gate Trap on the platform brings the shutters over the holes and prevents his return. In passing through the gi-ated door into the next chamber he resets the trap. In Fig. 236 the box is provided at its center with an oscillating platform, to which is rigidly attached an upright leaf or partition of the same width, which has its openings for the entrance In another form the box forming the trap is pro- vided with two apartments, separated in the usual way by a hinged grating, or self-closing door. In the first apartment is arranged a revolving shaft armed with vanes or paddles, and actuated by a spring. The animal, on entering this first apart- ment, releases by means of a treadle the detent of the revolving vanes, which pjress the said animal forward, causing him to enter the inner chamber, the said detent immediately checking the further revolution of the vanes. An index on the outside of the trap indicates, by the number of vanes re- leased, the number of animals caught. 10. The cage. This class includes those in which an inverted wire basket is entered between a set of converging wires which oppose a return. Sometimes this form of trap has a grated inclined door. 11. The noose. This is a very old form of snare, consisting of a running noose placed in the path of the animal. Such were the "springes to catch woodcocks," of old Polonius. They are used by poachers in England for snaring hares, and by boys for catching the less aristocratic rabbit. Fig. 238. Mouse-Trap. Among barbarous nations and fron- tiersmen a snare of this kind is attached to a sapling bent over and held by a trigger. The of the Fig. 239. Baker^s Trap. of the animal so arranged that when it depresses the tilting platform by its weight, the said attached leaf or partition is thereby swung past said opening, leaving the opposite side of the platform in like manner open to admit the next visitor. The en- tra])ped animal escapes on either side into a closed apartment. Fig 237. Revolving- Gate Trap. sprmging triggerreieasesthe sapling, tightens the noose, and swings the animal clear of the ground. The common mouse-trap is another form of the noose. A bow of spring wire is depressed at an opening, and the tam- pering with the bait allows the loop to spring up and strangle the animal ■53 against the top of the ^ opening. (Fig. 238.) Anklets. Cunning- H.\>r, March 20, 1866. The frame is made in three portions, reaching from a garter-band on the leg to the skate. The upper two portions are extensible on each other as the limb is flexed and extended, and the middle piece hinged to the lower Chtnninsfiam^s Ankle- Supporter. ANNEALING. 110 ANNEALING. one to ]iennit the said motion. It is intended to stiffen the ankle-joint and ijievent the ankle turn- ing sideways in skating. Tlie term is also apiilied to an article of dress wliieh forms an extension above the top of the bootee or the shoe, and forms in some cases a protec- tion for a weak ankle, in othera is merely an orna- mental e,xtension. Stockings, stiffened with steel springs or whale- bones, worn as a protection to weak ankles, may also be termed anklets. See GArPKliS. Annealing. Annealing is a process used in the manufacture of glass and iron for the purpose of rendering them less brittle. It is jierformed by allowing them to cool very gradually from a high heat, a .sudden reduction of temperature reiulering them hard and brittle. The singular properties of enameled glass are strikingly shown in Prince Ru- pert's drops and the Bologna vial. The former are prepared by allowing melteil glass to drop into water, where the drops which are not broken by contact with the water form irregularly elongated globular bodies tapering to a tail at one e.vtremity. These will bear a considerable blow on the thick end without breaking, but if a small piece be snapped off the tail the whole immediately falls into powder, emitting a cracking sound. The Bologna vial is a rude flask of some three or four inches in length by about one in diameter, and from Jj to J of an inch in thickness. If a leaden bullet be dropped into it from a height of three or foui feet, or it be struck a smart blow on the outsiile with a stick, it will not break, but the drop- ping of a grain of sand or a small sharp fragment of Hint into it will cause it to crack and fall to pieces. ITpon the jiroper annealing of glass much of its utility for many purposes entirely depends, and for vessels which are to be subjected to great e.xtremes of heat and cold, careful annealing is absolutely in- dispensaljle. Its neglect is one of the ]irincipal causes of the breakage of so many lam])-cliimneys, tumblers, etc., whose cost often forms such a con- siderable item in domestic e.xpenditure. See Gl.\ss. Annealing is also a necessary process in the manu- facture, by ((rawing, of wire and small tubing, as well as in making brass, copper, or .sheet-iron vessels by hammering and rolling ; the metal, by compression, becoming too hard and brittle for further reduction until annealed, after which it recovers its former softness and pliability. When molten glass is allowed to cool slowly, its pai'ticles assume a fibrous arrangement, which im- ]>arts a ceriain elasticity to the whole mass, so that it can transmit vibrations from one extremity to the other. When suddenly cooled, the interior par- ticles are enclosed by the solidification of the exte- rior before they have assumed the fibrous condition which insures the elastic stnicture or condition. Glass may be annealed by ydacing it in tepid water, boiling it for a considerable length of time, and then allowing it to cool gradually. Glass-ware is annealed by placing it, while yet hot, in an oven, technically called a /ecr, in which the gla.ss is allowed to cool very gradually. A com- mon form of the her is a long oven, with sliding or travelling pans to liold the glass-ware, which enters at one end, as hot as it comes from the liands of the glass blower or presser, and by the gradual accession of pans of ware is pushed to the other end, whence it issues at a temperature which per- mits it to be handled. The ]iartieles of glass are supposed to assume a different structural relation. when thus slowly cooled, which favors their cohe- sion, and permits a certain degree of resiliency or elasticity. When cooled suddeidy, there seems to be an inherent strain, a compulsory union, but faulty and fragile static condition, whose e(iuilih- rium is disturbed by an excitant in the form of a blow, which generates a tremulous motion among the particles, and pennits them to yield to the disruptive force. This disruptive tendency may arise from want of homogeneity, unequal contrac- tion, or something else. In the annealing of metals, cast-iron for instance, the metal is brought to a red heat, and then al- lowed to cool slowly. The rationale of this proc'css has been variously explained, and the most reason- able seems to be that the particles of metal take a ditt'erent arrangement under these circuuistances ti'om that assumed by them when allowed to cool rapidly. In the latter case the exterior jiortion of the metal contracts first, and ]iresses upon the interior portion, and the particles of the latter may thereby be compelled to take an arrangement which they would not were the cooling to take place at an equal rate in every part, and the process of cooling be long jirotractcd. It does not seem to be detemiined wliether the protraction of the process is merely necessary to insure an ei|ual rate of cooling in every part, but it is not a violent con- jecture that the said slowness may favor a jiarticu- lar aggregation of the particles, which gives them the greatest possible cohesion attainable with the structural nature of cast-iron. In making cast-iron malleable, as it is termed, a process much used in making builders' hardware, the metal is kept for several hours at a tenqierature a little below the fusing-point, and then allowed to cool slowly. From the prolongation of both stages of the process in this case, it is evident that the perfect result is best attained by giving the particles time, and not violently changing their structural relation ; unli'ss it be held that chemical changes in the furnace (such as parting with a poition of the I'lirbon) have to be taken into consideration, and that the change is not all in the mechanical disposition of the jiarticles. Tenqiering and annealing are nearly allied, but the processes are not conlbunded in the arts, owing to their different technical applications. The word "annealing" is derived from the .-\nglo- Sa.xon signifying to " kindle," and the heating is a necessary prelinnnary whether to withdraw the hardness incident to hanuuering and lolling of malleable metals, or the hardness incident to the rapid cooling of a casting in its mold. The pro- traction of the process of cooling the casting has a favorable effect upon its toughness and conqiarative softness. This is plainly seen by comparing them with chill-hardened articles, which are rendered hard and brittle by the sudden cooling. Exposure of the hot steel to a cold surface renders it hard. This is usually done by dipping the red- hot metal in water, but other cold surfaces which are rapid coiuluctors will answer the same purpose. A thin, heated blade jilaced between the cold haumu'r and anvil is hardeni'd by rapid cooling. Thicker pieces, under the .same circumstances, are somewhat hardened, but may be fdcd. Placed on cold cinders, or other bad conductor, the steel cools nioie slowly and becomes softer. Placed in hot cinders, and allowed to cool by their gradual extinction, it becomes still softer. Encased in a close box with charcoal-powder, raised to a red heat, and allowed to cool very slowly, it reaches its softest state, except by a partial de- composition, as in the following process. ANNEALING. Ill ANNEALING. The steel is placed in a close box with iron turn- ings, filings, or scales, lime, or other matters, which will eliminate the carbon from the steel, and reduce it to the condition of pure, soft iron. This is the process used in softening plates and dies under the modem system of bank-note engraving invented by Jacob Perkins (cited below). Analogous processes are had in the case of cast-iron, producing the various grades of hardness, from the chilled east-iron to the soft malleable iron-castings. The annealing of steel, to soften it for the uses of the die-sinker and engi-aver, is effected by heating it to a bright cherry red, and sutfering it to cool gradually in a bed of charcoal. Another process, adopted by the writer, has been to imbed the steel blanks or forgiugs in lime within a cast-iron box. This is heated to redness in the fire, remaining a sufficient time to insure an eijual heat of the articles inside ; the box is then removed and buried in hot ashes, which protract the process of cooling for sev- eral days. See TEiirEKiXG. Perkins's process of transfer-engraving is as fol- lows : — A soft steel plate is first engraved in finished style, either by hand or mechanically, or the two combined, and the plate is then hardened. A de- carbonized steel cylinder is next rolled over the hardened steel plate by powerful machinery until the engraved impression of the plate appears in relief upon the roller, the hollow lines of the plate being salient ridges on the cylinder. The roller is then reconverted to the condition of ordinary steel, and hardened, after which it serves for giving the intaglio impressions to any number of decarbonized plates, every one of which is an absolute countei-part of the original. Each plate when hardened will afford 150,000 impressions, and in the event of acci- dent to the transfer-roller, any number of new rollers with the design in cameo may be obtained from the original plate. The metallurgic process was explained by the inventor in the thirty-eighth volume of the Transac- tions of the Society of Arts. He there states that to decarbonize the plates they are placed in a vertical po.'iition in cast - iron boxes not less than three fourths of an inch thick, and surrounded on all sides by iron filings not less than one half an inch thick. The boxes are then placed in a furnace, and, aftump-pisr ton to descend. A hydraulic ap- paratus is brought into action to maintain the parts in this posi- tion until the pump-valves have had time to change. The eipii- librium-valve is then opened, the steam passes above both pistons and drives them down, the pressure being nearly e(iualized on the upper and lower sides of the small piston, wdiile nearly two thirds of it acts on the upper side of the annu- lar piston, which has a partial vacuum beneatli it, to aid in the work. The effective stroke is also aided by the dead weight of the cross-head, which weighs over ninety tons, and by the weight of the pistons and rods of the engine. Each engine has two air-pumps of forty inches diameter, and five fe.^t stroke. The steam is cut off in the small cylinder at from one fourth to two tlurd^ of its stroke, according to the load, and is then fartlier expanded in the large cylinder. When working with the net jiower of 350 horses, the average consumption is 2J pounds of Welch coal per horse-power per hour, or 75,000,000 pounds of water raised one foot high with 94 pounds of coal. The duty of the engines has been as high as 87,000,000. 'See Dl'TY. The Lynden and Cruipiius engines work eight pumps, each of seventy-three inches diameter and ten feet stroke. The Leeghwater works eleven pumps of sixty-three inches diameter, ten feet stroke, each engine being calculated to lift si.xty- si.x cubic meters of water per stroke. Fig. 256. The three engines are capable of discharging 2,000,000 tons of water in twenty-four houre at their full depth. They were erected by two Eng- lish companies. An'nu-lar Gear'- Wheel. A wheel whose teetli are on the concavity of an annulus, or ring, which isdestituteof web or sjiokes. An'nu-lar Mi-orome- ter. A form of the circular micrometer invented by Fraunhofer of Mnuich, con- sisting of an annular glass disk whose central aperture isabouthalfaninchindiam- Annular Whed and Pinion. eter and bounded by a me- tallic ring which is cemented to the inner edge of the glass. The metallic ring is used to determine differences of declination between stars, from the differences of time occupied by them in traversing different chords of the ring. See Circular Micrometf.k. An'nu-lar Pan. A ring-shaped trough in which the vertical grinding-wheels of an ore-crusher re- volve. The main shaft may stand in a central aperture of the bed and receive motion from a horizontal Fig. 257. AnniiUiT Pan. shaft beneath. The pulverized ore, mixed with water, is loosened up by rakes, and scraped from the sides to the wheel-tracks by knives. The wheels follow different tracks. I'he pan form of amalgamator is a favorite, and several illustrations may be seen under Amalgama- tor, Figs. 144-153, pp. 78-81. An'nu-lar SaTW. The annular saw for cutting pearl-button blanks is a steel tube with a ser- rated end. The annular saw of the surgeon is the tTqmn, or, preferably, the trephine ; which see. Other varie- ties of annular saws are known as crown, barrel, drum, or ciiUnder saws ; which see. An'nu-lar Valve. A gravitating-plate valve of a circular form and with a circular central aperture. It works u]ion a stem by the upward pressure of water, and clo.ses an annular aperture when the lift- ing force is removed. See illustration in Screw- PrOI'KLLF.K Sn-.AM-F.Nf.INE. An'nu-lat-ed Col'umn. A clustered column girt by bands. An'nu-let. A flat molding ; a small square member in the Doric capital. An-nun'ci-a-tor. Annunciators are substitutes ANNUNCIATOR. 117 ANODE. for the old-fashioned an-angement of bells in hotels, etc. Instead of each room being connected to a separate bell in the office of the hotel, the bell-pull of each room is connected to a single bell, which gives notice to the clerk or jiorter, and at the same time a pendulum with the number of the room is caused to vibrate, or the shield is removed from a number corresponding to that of the room. The devices are various. The general scheme is to con- nect the wire from the room to a numbered plate, which is moved up to an opening and thereby ex- poses its number to view. The wire at the same time trips a trigger which actuates the hammer of tlie bell. A variation in the mode of operation is found in those annunciators whose openings are all covered by pivoted shields, the numbers being per- manently attached in the rear. The motion of the wire trips the sounding-hammer as before, and at the same time trips the shield to which it belongs, and causes it to oscillate from before the opening and e.\pose the number to which it Ijelongs. A crank o])erated by the hotel clerk restores the noi-mal condition after the number has been ob- serveil. H(iRSF.\LL, October 4, 1853, and Hale, April 22, 1856, are among the earlier inventors. In Horsfall's, the wire from the room operates a rod whose horizontal lifting and tripping arm ex- tends beneath it5 appropriate swinging inde.x-plate. The rod and arm are arranged in such relation to the rocking-frame which carries the alarm-bell, th;it, as either of the rods is raised for the pur- pose of trip[iiug one of the index-plates and expos- ing its number to view, the frame and bell will be also raised, and the pendulous hammer allowed to descend some distance. ^\lien the rod descends after triiiping the index-plate, the rocking frame and bell also descend, and the contact of the short arm of the hammer with a lever causes the hammer to sound the alarm, subsenueut to the exposure of the number. The index-plates are thrown back to their cover- ing position by an eccentric rod and connecting devices. In the e.rample annexed, a crank arm is at- tached to the center of the lever, and is acted Fig. 258. movement of the slides is limited by trans- verse bars above them, which cross the line of their motion. The mechanism in Fig. 260 is so ar- ranged and connected with a knob in the room of a hotel, that as the knob is actu- ated b}" the occupant a bell will be sounded at the office, and a slide moved which dis- closes the name of the article wanted, such as "water," " boots," "messenger," etc. A slide in the room is made to cover the names of articles gen- erally wanted by a guest, and coiresponds with a similar slide and names in the of- fice. The extent of the pull determines wliat name shall be ex- posed, and the guest, by noticing the effect at the /)!(// end, may determine the effect at Hotel Annunciator. upon by the wire, can-ying a pendulum in front of the face of the annunciator, and by its vibration denoting the wire acted upon and the number of the room. In Fig. 259 the annunciator is so arranged that the lifting of any wire shall not alone expose the number of the apartment, but shall lift a plate, and through the connecting wire cause the hammer to strike upon the bell. The slides, with the numbers upon their faces, have projections on their rear with holes through which the ^\-ires pass, and the upward Fig. 259. Annunciator, the other end, as the slides are coincident. Another foim is a combined hydraulic and pneu- Hg. 260. matic annunciator. The chamber of the guest and the hotel office are each ]irovided with an indexed gage, consisting of a hollow tube containing a colored liquid. At the back of each tube is a graduated in- dex marked at intervals, "fire," "light," "water," "brandy," "towels," etc., as may suit the aver- age of customers. The respective tubes are con- nected by an air-pipe, into which air is injected by. the guest, to raise the liijuid in the respective tubes to the point which indicates his wants. An'ode. That pole of the galvanic battery by which the electricity enters into the substance suffer- ing decomposition ; the positive or + pole. This nomenclatuie was adopted by Professor Faraday. ANORTHOSCOPE. 118 ANTI-FRICTION METALS. A-nor'tho-scope. The name given by M. Pla- tiMii of Brussels to an instrument invented by him and intended to produce a peculiar kind of anamor- phosis by means of two disks rotating i-apidly one before tlie other ; the hinder one is transparent and bears distorted figures, wliile the front one is opa(Hie and is pierced witli a number of narrow slits. On revolving the disk the distortions appear as amusing and interesting figures and pictures. As in other toys of a similar kind, the etfect depends upon the persistence of impressions on the retina. — Brande. It probably suggested the Zodrope, which has lately become so popular in the United States. See TuAU- MATROPE ; PhENAKISTOSCOPE ; SritOBOSCUPE. An'sae. (Artillery.) The handles of some kinds of brass ordnance. An'ta. (Architecture.) A pilaster oecuiTing at the corner of a flank wall. An'te-fix'se. (Architecture.) a. Ornaments placed below the eaves of a Grecian temple ; perfo- rated to allow the escape of water from the roof. b. Blocks covering the termination of the ridge formed by the overlap of the tiles on a Grecian roof. An'te -mural. (Furtijieation.) An outwork con- sisting of a higli, strong wall with turrets, for the defence of a gate. An-teri-des. Buttresses. Ante so-la ri-utn. A balcony facing the sun. An-te-venna. An awning, or shade roof. An'tho-type. A photographic process in which the colored juices of the wild poppy, rose, stock, etc., are ell'nced by the action of light. Au'thra-cene. A solid crystalline hydrocarbon, ac- com]mnyin,L,' najilithaliTie in the distillation of coal-tar. An-thra-oom'e-ter. An instrument for mea.sur- iug the amou)]t of carbon in a given case. — Beil. An'ti at-tritiou Compound. For the bear- ings of machinery and a.xles of carriages. See Lu- bricant ; Alloy ; Anti-fkiction Composition ; An'ti-fkiction' Metals. An'ti cli'nal Line. (Mining Engineering.) The axis of curvature on the arch or saddle of a range, on each side of which the strata dip. Opposed to Syu- eliiiiJ. An'ti friction Bearing. A rolling bearing for Fig. 261. Anti-Jriclion Bearing. an axle or gudgeon. The intention is that the parts primarily in contact shall not rub against each other, but move in unison. In one form the roller surfaces impinge upon the surfaces of the a.xle and its box (Fig. 261) ; in another form the rollers are on axles (see Fig. 263). A familiar illustration is also found in the improved form of hanging grind- stones (see Fig. 265). The " Palier Glissant," of Girard, consists of a journal box whose lower part is grooved and has an aperture communicating with a pipe through which water under a heavy pressure is introduced beneath the journal. The eflect of this is to slightly lift the journal, allowing a very thin film of water to escajie, which etl'ectually lubricates the bearing, entirely preventing contact of the metallic surfaces. This is analogous to the hydraulic pivot for tur- bine wheels, invented by the same engineer, in which the weight of the turbine and its vertical shaft is supported by a water cushion, in the same manner as is the horizontal axis in the foriner case. An'ti-fric'tion Box. An enclosure for the balls or rollers of a step or bear- ing. An'ti-fric'tion Com- po-si'tion. A luljricat- ing material or compound to diminish friction of parts moving in contact. The compounds are numerous, and include the fol- lowing materials in various combinations : — Alloys. See Anti-fric- Mucilage. Anti-friction Box. TioN Metals. Alum. Asbestus. Bitumen. Borings of Metal. Cork. Cotton. Fiber, Animal. Fiber, Vegetable. Gelatine. Graphite. Gum. Gypsum. Lard. Lime. Oils of various kinds. Pasteboard saturated with petroleum. Pith. Plumbago. Sal-ammoniac. Shavings of wood. Silicate of soda. Steatite. Sulphur. Talc. Tallow. Tannic acid. AVood saturated with oil. AVool flock. An'ti-fric'tion Met'als. Alloys principally u.^ied for l)earings of machinery and for journal boxes. Several are described under the head of Alloy. Some variations are found in the formulas, com- paratively few agreeing even in the composition of Babbitt's metal, patented in 1839, and so nnudi used throughout this country and in Europe. The lil- lowing table will give the composition of several : — ? S| 1, ° i, «i 3 d u iS 1 1 1 s Babbitt's . 50 5 1 Another formula 10 2 1 Fenton's 10 10 in Belgian, for objeota ex- po.sed to friction 4 5 20 hin *' expo.«ed to shocks 1 2(1 K " expo.sed to heat . 5 17 1 025 Dinsman's ilfi S 4 1 0.5 Richardson's •2 62 .S4 1 1 StrubinK's IS 2.5 75 4.5 Engl. Pat. 896 of 1863. 40 28136 2 1 1.5 JiNTI-FRICTION PRESS. 119 ANTIMONY FURNACE. An'ti-fric'tion Press. A press in which tlie power is obtained by the rolling of two cams against an intennediate roller. See Rollisg-C.^m Press. Anti-friction Pulley. A device for the pur- pose of lessening the friction of the sheave on its pin. An annular system of anti-friction rollers sur- round the pin, and rotate on their own axes as they revolve on the pin. They are maintained at their Kg. 263. 1 X M 'M — 1 D (: . ^1 \r4 K ]:i ;] B Anti-Jriction Pulleys. proper relative distances by a ring or series of links, so that the faces of the roUers themselves do not come in contact, as contacting faces, under these circvmistances, would be revolving in different direc- tions, and great friction would result. An'ti-fric'tion Step. A bearing at the end of a rotating shaft, to Fig 264. diminish the fric- tion of the con- tact with the step when pressure is applied longitu- dinally. In the step for propeller shafts, the loose collar i? has anti- friction wheels on radial axes, which act between a collar on the pro- peller shaft and a fixed plate trav- ersed by said shaft. the ob- ject is an anti- friction bearing to take the end strain of the shaft. A somewhat similar arrangement is used for ver- tical shafts in .some cases. See Fig. 262. An'ti-fric'tion Wheel. The wheels C C form a rolling bearing for a shaft, so as to diminish its friction thereon ; the bearings for the axis of a grindstone, for instance, as shown in Fig. 265. Analogous devices are found in many machines and in carnages. See Jourx.^l Bearings ; Axle. An ti-gug'gler. A small tube, inserted into the mouth of a bottle or carboy to admit air while the liquid is running out, and thereby prevent guggling or splashing of corrosive liquid. An'ti-in'crus'ta-tor. A device or a composition to prevent the inciitstation of steam-boilers. One class of improvements in tliis Une is mag- netic ; it depends upon keeping up an electric action which prevents the adherence of the scale of salts of lime, etc. Another class consists of mechanical agents, and a third of chemical. See IxcRU.sTATioN in Boilers. An-tim'e-ter. An optical instnunent for measur- Anti-JHction Step. Fig. 265. ^' ,1111 " L-JT - Anti'friction Wheels. ing angles. A modification of Hadley's Quadrant, long since supereeded by superior instruments. An'ti-mo-ny. Equivalent, 129.03. (Svmbol, Sb: Stibium.) Specific gra-sity, 6.8. Melts" at 995.5, Fah. ; passes off in vapor at a white heat. It has a peculiar taste and smell. It is a bluish-white, brit- tle metal, and is much used in hardening tyjie-metal, to whiih it also imparts the faculty of not shrinking in cooling. It enters into the composition of some other alloys, such as one kind of speculum metal. Its salts are much used in medicine and pyrotech- nics. Antimony was known to the Hebrews as a cos- metic. AVith it, it is supposed that the wicked Jezebel painted her eyelids and eyebrows, B. c. 884, just before she was thrown out of window by the orders of the cruel Jehu, wlio trod her under the feet of his horse, and left her to be devoured by dogs. The Arab women use JcohJ to increase the brillian- cy of the expression of their eyes, as the Hebrew women did down to the times of Jeremiah and Eze- kiel, and later. It is yet an Oriental custom. Lit- tle toilet boxes and bottles for kohl are found among the relics of the ancient Eg\-i)tians, and are preserveil in many collections ; for instance, iu the Abbott Collection in the possession of the Historical Society of New York. Basil Valentine introduced the metal antimony into the practice of medicine. Observing that some swine fattened surprisingly quick after the adminis- tration of the drug, he tried it on some of the monks in his vicinity, who had become much attenuated by their Lenten fast. The account says that they were all killed, and hence the name Anti-woine. It was previously called Stibium, and yet retains that title in scientific nomenclature. An'ti-mo-ny Furnace. The antimony furnace. Fig. 266, as at present used, is a reverberator)' whose hearth is foimed of clay and sand solidly rammed together and sloping from all sides towards the middle, at which j)Iace is the discharge opening, temporarily closed with coal-ashes. The air chan- nel passes up through the fire-bridge, and the fire ANTIMONY FURNACE. 120 ANVIL. Antt/noni/ Furnace. is in the chamber at the end, the flame reverber- ating in the eliamber above tlie ore. Tlie charge is introduced at tlie usual opening, which is closed by a door while the operation is in progress. The slag is drawn oil' at the same opening. The sul- phuret of antimony is found associated with gangues of ([uartz, sulphate of baiytes, and carbonate of lime, and is easily fused therefrom by the application of lii-at in the furnace described. It is not obtained jierfectly pure therefrom, but is fused again under coal-dust in crucibles on a reverberatory lu'arth. The former mode of obtaining the metal from the ore consisted in exposing it in luted ciaicibles which are placed in a furnace (Fig. 267). The crucibles Iiave openings in the bottom, and are luted to a Fig. 267 Antimony Crucible. perforated tile which forms the roof of a lower chamber containing a pot into which the metal escapes as the operation proceeds, The gangtie re- mains in the crucible above. This method is found to be very destructive of crucibles. The crude antimony is purified by repeated ex- posure at moderate heats to e.xpel the sulphur and fuse the metal. The difficulty in the treatment arises from the volatility of the metal, which escapes if excess of heat be appUed. This is in the domain of cheniistiy. The ordinary alloys of antimony are : — Antimony. Lead. Tin. Copper. Bismuth. Type Metal 1 i Stei-eotvpe Metal 1 6 Music Plates 1 1 1 Britannia Metal 8 100 Pewter 1 12 An'ti-qua'ri-an. A size of drawing-paper measur- ing 52^ X 3Ui inches, and weighing 233 pounds to the ream. An-tique' [an-teek']. (Type.) A fancy style in which each stroke of the face has an equal thick- ness. There are many varieties. An'ti-sep'tic. See Wood, Peeservation of ; Food, Puesei!Vation of. An'vil. {Fonjiiiff.) 1. This is ordinarily a mass of iron w hich sustains a piece of metal while the latter is being forged to shape. In its ordinary form, where the hanmier is worked by hand, it has a square central block, and a strong, projecting, and pointed piece of steel called the beak or horn. The quarter has holes for tools such as cutters and swages, and the whole is mounted on a block. Isaiali speaks (xli. 7) of him that smites the anvil in connection with the art of tlie goldsmith, and also refers to the subsequent soldering. In heavy operations, such as the forgings of heavy ordnance and shafting, the anvil consists of an enormous iron block imbedded to a considerable depth and founded on jiiles or masonry. Fig. 268 shows the ordinary blacksmith's anvil, Fig. 268. Amnl and Tools. and illustrates the methods of making bolts. a face of the anvil. b horn or beak. c hardy hole, with rounding-iron inserted. n body or web of the anvil. In forming a bolt by the drawmg-doicn process, the size of the bar of iron is reduced at proper intervals by fullers, and the operation is completed by the ronnding-irons, shown at c and d, leaving the head of the full size of the bar h, which is then cut off with a chisel. In upsctlinij, the body of the bolt remains of the full size of the bar, while the head is enlarged by ANVIL. 121 ANVIL. upsetting, that is, driving the end down upon the body with a hammer, thus forming an enlargement ; or it is enlarged by jumping, that is, beating the heated end forcibly on the anvil ; in either case, the head of the bolt is finished by means of the he;idiDg-tool, two varieties of which are shown at e and/. The third process of bolt-making is by welding or building up; a bar of flat iron- is bent around the horn of the anvil, as shown at i, and the bar of round iron intended to form the body is inserted through it ; the ring is then cut off at the proper length by the chisel, shown at k, and the head finished as usual. 3 is a swage for forming hexag- onal heads to bolts, or other hexagonal or tri- angular forms, and I, m, represent bolts, in the first of which the head is partiall}' made, and in the latter completed. Tubal Cain, the descendant in the sixth genera- tion of Cain, is the first recorded blacksmith, and the neces-sities of his craft must have introduced the an\-il before the time of CinjTa of Cyprus, who is credited with the invention by Pliny. The anvil of the Greeks and Romans (iTunM) was usually of bronze, and was shaped like our own. It had a horn, and was mounted on a wooden block. Among numerous varieties of anvils for special trades, and to give a more extended usefulness to the space occupied by the implement, may be cited one in which a shears and punching - machine are corn- Fig. 269. Anvil SJuars and Punch. pactly placed beneath the anvil, and are worked by handcrank, pinions, and segment-rack. Another anvil has a secondary horn, is socketed upon the be,ak of the anvil, and confined there by a hinged link. On the upp>r surface of the secon- dary horn are grooves into which the shoe is driven Fig 270. ' so as to bevel the inner edge, to facilitate its free- ' ing itself from snow which becomes packed inside , it. In Fig. 271 the anvil is supported by a stout spring, whose recoil is par- j tially counteracted by the rig- 271. light springs above. The ob- ' ject is a certain amount of re- siliency without jar as the anrtl regains its normal posi- tion. The gold-beater's anvil, when using the forging-ham- mer, is a block of steel, four inches long, and three broad. The ingot is reduced by this operarion to a thickness of one sixth of an inch. The anril used in the sub- sequent operation is a block of black marble twelve inches square at top, and eighteen inches deep, framed in awood- en block. Anvils are tempered in a float, instead of being merely Spring Anvil. dipped. The rapid formation of steam keeps the water from close contact with the metal, and in the Jioat a copious stream of water is ]>oured upon the surface to be hardened, falling par- ticularly upon the center of the face. Large anvils are slung from a crane into a tank beneath a fall of water, where they are hardened ; being lifted before the main bulk of the iron is cooled, the remaining heat is allowed to draw the temper to the right degree, when the anvil is in- stantly immersed. The casting of an anvil weighing 358,000 pounds is thus described by the " London Engineer " : — " Another immense casting has been turned out by the Midland Works, Sheffield, viz. a 160-ton anvil-block for a steam-hammer. In the center of the floor a great pit was dug, and in this the mold was formed, the anvil being cast -with its face downward. The mold was 12 feet square at the base, and 11 feet 6 inches deep, and it was es- timated that nearly 170 tons of iron would be required to fill it. At intervals outside the shop were five furnaces, and at six o'clock in the morn- ing these commenced to pour their molten con- tents into the huge chasm, and continued until about five o'clock, when the operation was declared to be successfully completed. From four or fiv6 diff'erent points streams of liquid fire were slowlj rolling to the edge of the pit, where they fell amidst showers of starry sparks into the vast mass beueath. A metallic rod was thrust through the mass to test its perfect liquidity, and, this having been satisfactorily proved, the top of the pit was carefully closed, to be opened no more until the metal has cooled, which will probably be in about seven weeks. Tlie anvil is intended to be placed in a gun-manufactory in the vidnity. The bed consists of a first course of great piles, which have been driven by steam-power 15 feet into the solid ground. Upon these is a thick bulk of oak, solidly braced and bolted together, and the combined mass forms the bed of the anvil. Only about half a foot of its bulk will appear above ground. The block will have to sustain the blows of a 25-ton steam-hammer which will be employed in forging 600.pounder and 300-pounder guns for Mr. WliitHorth." Jlr. Ireland, of Manchester, England, has a porta He plant for casting large anvil-blocks in the posL- ANVIL-CUTTER. 122 APIARY. tion they are to occupy on the premises where they are to be used. He furnishes everything but the iron and tlie blast. " The plant used at Mr. Bessemer's works con- sisted simply of a cupola 4 feet in diameter within the lining, and 12 feet deep to the charging-door, constructed on the "upper tweer" principle. A belt about 2 feet 9 inches deep surrounds the cylin- der at about 7 feet from the ground, and into this belt the blast is delivered by two large pipes, one on either side. The upper row of tweers consists of sixteen orifices, each about 3 inches in diameter, ranged ei|uidistantly above the level of the main supply pipes, wliich discharge into the lower ])or- tions of the belt. The lower tweers are only lour in number, each about 8 inches in diameter, dis- posed opposite each other, but not opposite the main pipes. By this means the blast is very equally distributed through all the tweers. At the time of our visit, this cupola was bringing down 9 or 10 tons of iron per hour, and Mr. Ireland has recently cast an anvil-block, weighing no less than 205 tons, at the Bolton Iron and Steel Works, at the rate of 25 tons per hour, with two cuiiolas precisely similar to the one under consideration. The consumption of coke is very moderate, when once everything is well warmed up, not greatly ex- ceeding one cwt. of coke per ton of iron. A strange contrast exists between such operations as this and those in which Jlr. Ireland first engaged in the year 1809, when he, in common with many other founders, considered it a good day's work to melt a single ton of iron in ten hours. "it is not easy to see how the casting of large masses can be more economically effected than under this .system. The lining of the cupola being removed, it is brought into the condition of an ordinary boiler shell of no very excessive weight, easily admitting of transport by either rail or water. The whole att'air being carried out by Contract, the manufacturer is saved an immense amount of trouble and responsibility, while all the operations being conducted by those who possess a special knowledge and experience of the matter in hand, the best results are sure to be obtained at the least possible outlay. In many cases, without the existence of such a system, the manufacturer would find himself compelled to erect a cupola of large dimensions for which, the block once cast, he would have no further use." — London Enriineer. 2. In the Laidley car- tridge (Fig. 272) is an a?n-i7- plate A which is held in position by a shoulder d on the capsule. On the plate is a nipple which holds the percussion-ca]!, and the latter is exploded by a blow on the rear, de- livered by the nose of the gnn-lock. B is the bullet retained by spinning down the edge of the capsule. 3. A little pennon on the end of a lance. Anvil-cut'ter. A shears operated by a blow of a hammer, for the use of blacksmiths. The lower cutter is upon .one end of a lever whose other end is elevated by a Anvil-Cutter. spring to open the jaws. Fig. 272. Cartridge AnviL Fig. 273. The jaws are closed by a blow of the hammer upon the on er end of the lever. A-or'tic Com-press'or. An instrument for com- pressing the aorta to limit the flow of blood from thence to the divided femoral artery in ca.se.s of am- putation at the hip joint. See Surijc&ii-Geiieral Barnrs's Jicport, Circular A'o, 7. Ap'er-ture. 1. (Architecture.) An opening in a wall or partition:, for a window, door, ventilation, or to fonn a recess. The sides are jambs. The top is the head, or lintd. The bottom is the silt, or threshold. 2. (Optics.) The orifice in the end of a telescope or other optical instrument through which light en- ters. The diameter of the exposed portion of the object-glass ; as, " 6-inch aperture." Aph'lo-gis'tic Lamp. Literally, flame/ess. A lam]j in w liich the wick, of platinum wire, is kept constantly red-hot by the slow combustion of alco- hol, heated by the wire itself. A'pi-a-ry. A place where bees are kept. It gen- erally assumes the form of a house forming a com- mon shelter for the hives, but in some cases the hives are more closely associated and form a cluster of families, occupying a bee "palace." This is fre- quently an ornamental structure with a number of apartments for brood comb, and outlying, removable boxes for containing suqilus honey. Tlie interior has provi.sion for ventilation by gauze-lined tubes, and the portions communicate by ducts, or by holes in the partitions. Provision is made for part- ing off certain portions which are removable with their tenants and provisions to form a nucleus for another cluster of families. The intention of the bee-palace arrangement has been to give the bees the advantage of combined ettbrt and at the same time prevent natural swarming by making colonies removable. Experience indicates that they run well for a season and then dwindle, becoming a prey to their natural enemies, among which the most fatal is the bee moth. Individual families are com- paratively .short-lived, and modern apiarists have ob- tained such a connnand over the fraternity, that the families may be divided at pleasure, with a frequen- cy and success dependent upon the resources of the bees for food and the salubrity of the season, always bearing in mind the tribal economy of the bees, which requires the presence of a queen. In some parts of the world the apiary consists of a collection which are formed into a village with avenues. They are sheltered in winter-quarters, and on the approach of spring are carried out to favor- able localities, where they work during the honey- making season. This is especially the case on some ]>arts of the continent of Europe, whcie bee-keeping is systematized and followed as a regular branch of industry, the aim being to glean the favorable terri- tory of aU the bee-supporting nutriment. Fig. 274. n r □tfn n n Apiary. APIARY. 123 APIARY. The devices in apiaries, not considering those be- longing to hives, which are considered separately (see Bkehive), are for ventilation, protection against storms and depredators, and for housing during winter. In the compound hive (Fig. 274) the apartments are associated side by side in an outer case, and com- municate with each other laterally, and each with its removable honey-bo-x above. This is an illustration of the lateral arrangement ; others are associated vertically. In Fig. 275 is shown another form of apiary whose "pigeon-holes" are occupied by drawers which are interchangeable and made to conimu- L Fig 275. ' c c B m H ] B m a m m m m ' /■ — »■ - ,» 5^-- Apiary. nicate as required. Doors inclose the front, and the whole is mounted on a pillar to raise it out of the way of mice, etc. VentUatiug arrangements are made in the interior, the ramifications extending to the pockets which contain the drawers fomiing the apartments. An ornamental character is given to the whole to make it an agreeable object in a bower or on a gi-ass plat. Another bee-palace has a frame on which the Fig. 276. hives are supported, shelves for honey-boxes, doors for examination or change, and an enclosing shed above for protection from heat and wet. The lower part of the case has inclined sides and a falling door at bottom for the discharge of oH'al. In Fig. 277 the moths ami grubs falling from the hives are directed, by the inclined sides of the lower portion, into the trap beneath. The trap has a Fig. 277. Bet-Palace, funnel-shaped conductor, a perforated diaphragm, and a detachable bottom by which the insects and otfal are removed. Additional apartments for the e.xtension of room are added above and on the sides, and admittance to them is afforded as required by withdrawing the slides wliich command the ducts of communication. Fig. 278 shows a hive w'hich has a sunken hatch- Fig. 278. Apiary. APLANATIC LENS. 124 APPLE-PARER. way in the center, extending into a pit so as to tring the floor of the hive about on a level with the surface of the ground. Tlie walls and ceiling are double, and have a layer of non-conducting material. A central chinniey removes the vitiated air, and reg- isters determine the admission of air to each hive in the group. It is supported by posts which rest in cups of water to prevent access of ants and mice. The devices have particular reference to means for maintaining an even temperature ; the double sides and non-conducting material obstructing the pas- sage of heat outward in winter, and also moderating the elt'ect upon the bees of the summer heat strik- ing upon the sides of the hive. The equality of the temperature is also conserved by the nearness of the ground, while provision is made for removing effluvia or coiTupt air which might accumulate in the pit. Ap'la-nat'ic Lens. A lens constructed of dif- ferent media so as to correct the unequal refrangibil- ity of the ditl'erent rays. The object to be attained is that rays parallel to the axis of the lens or diverging from a point on its axis, after passing through it and suttering refrac- tion at its surface, shall converge to a single point, the true focus. See Aohro.matic Lens. A-pol-lon'i-con. A large chamber-organ played by key-boartls or by barrels, and exliibited in Lon- don some years since. It was constructed by Flight and Robinson in 1817. It had 1,900 pipes, 45 stops, 5 key-boards and 2 barrels. The number of keys acted upon by the cylinders was 250. Ap'o-me-com'e-ter. An instrumentfor measur- ing bights, invented by a Mr. R. Millar, and manu- factured in London. The apomeeometer is constructed in accordance with the pi'inciples which govern the sextant, viz. : As the angles of incidence and reflection are al- ways equal, the rays of an object being thrown on the plane of one mirror are from that reflected to the plane of another mirror, thereby making both ex- tremes of the vertical hight coincide exactly at the same jioint on the horizon glass, so that by meas- uring the base-line we obtain a result equal to the altitude. The eye of the observer when in position will be at the lower end of the hypotenuse, and the summit of the object at the other. Keeping the line of vis- ion, which forms the base, exactly horizontal, the observer approaches the object till the images coin- cide, when the base will agree in length with the ]ierpenilicular, and the measured length of the for- mer will give the hight df the latter. A-poph'y-ges. A molding of a rounded concave form. See iMoLDINO. A-pOB'tle. (Naidical.) A knight-head or bol- lard-timber where hawsers and heavy ropes are belayed. A-pos'tro-phe. An elevated comma-shaped point ('), to indicate an abbreviation, as "don't" for "do not" ; to mark the plural of figures or letters used as words, as " two 20's," " the font lacks A's" ; or to mark the possessive, as " lago's trick." Appa-ra'tus. 1. A set of tools or implements for a given duty, experimental or operative. 2. A complex instrument or appliance, mechan- ical or chemical, for a specific action or opera- tion. 3. {Nautical.) A ship's war equipage and am- munition. Ap-par'eL 1. Body clothing. 2. (Niiulical.) Tlie masts, rigging, sails, and other gear of a vessel. Ap-pend'a-ges. (Shipbuilding.) Relatively small portions of a vessel projecting beyond the general shape, as shown by the cross-sections and water-sec- tions. These parts usually consist of, — The keel below its rabbet. Part of the stem and stern-post. The rudder, rudder-post, and screw (if any). These volumes are calculated separately and added to the main part of the displacement. Ap'ple-cor'er. Many of the apple-parers have attaclinieuts lor dividing the fruit into quarters, or still more minutely ; in some cases the apple is pushed from its impaling fork against a cutting-tube with radial knives, the tube receiving the core and the knives making the division. A device for cor- ing, slicing, and stringing fruit is shown in Fig. 279. The fruit is placed above the coring-tube and its radial knives, and is pressed down upon the Fig. 279. Fig. 280. Apple- Corer. same hy a plunger whose central part projects suffi- ciently to drive the core into the tube. The quar- ters are pressed upon sharp plates which enter the fruit a short distance, and are the means of introdu- cing strings which depend from the said plates ; the successive pieces push their pred- ecessors ott' the plates, and the pieces are thus strung and sus- pended until a sutficient quan- tity is gathered. The strings are then removed and empty ones attached. Fig. 280 is an example of an implement consisting of a tube or circular cutter of sheet metal, slightly tapering from the cut- ting edge, and with four or more radial cutters projecting from its circumference. The central plunger serves as a guide in ap- jdying the implement, and is afterwards the means of ejecting the core.' Ap'ple-par'er. This is an ingenious American device, and created mingled emotions of ad- mii'ation and amused surprise when it was introduced into Eng- land ; thedateisnotremembered, but it was referred to as a novelty i about 1840. There are now over eighty jiatents, which appear to Ij 1 ^ Apple Carer and Quatterer. APPLE-PARER. 125 APPOINTMENTS. agree in one respect, that is, the rotation of the fruit on the end of a fork. The operation requires two motions, which vary in tlie ditiereut machines. 1. The cutter describes a semicircle in the plane of the a.xis of the fork while the fruit is rotating, so that it may remove a paring from the stem to the blossom end, following the rotundity of the fruit. 2. An oscillatory motion is given to the fork, whose stock describes an arc in the plane of its length, presenting the rounded surface of the rotating apple to the knife, which cuts a continuous paring from the fniit, from the stem to the blossom end. The first patents recorded are those of CoATES, 1803, and Cruttenden, 1809 ; Gate.s added the quartering in 1810. The Patent-Office records perished in the tire of 1836. We find that in Mitchel'.s patent, April 13, 1838, the first granted after the fire, that the knife was operated by hand while the fi'uit was impaled upon a fork which was rotated by gearing. The pared apple was then pushed through an opening with a cruciform knife arrangement, by which it was quartered. Fig. 281. by gear connection with the hand-crank shaft. The knife returns automatically to the place of com- mencement after making its efleetive sweep. In Fig, 283 the rotation of the fork is obtained by one motion of the hand in an arc of a circle, the smaller cog-wheel on the main shaft gearing into Apple-Parer. In Fig, 281, date of 1857, the threaded shaft draws the slide, bringing the paring-knife against the sur- face of the apple which is impaled on the fork. The knife-stock is so pivoted on its shaft as to jire- sent the blade to the app'e while following its con- ve.xity to some e.vtent. The work is not so thor- oughly done on the ends as by later inventions in which a positive semicircular sweep is given to the fruit or knife. The slicing-knife, which follows the parer, cuts the apple into a spiral, leaving a cylin- drical core-piece attached to the fork. In a later ma- chine, cams on the main and an intermediate wheel combine to oscillate Fig, 282. AppJe-Parer. a rack, which sweeps the paring-knife al- ternately from the stem to the caly.x of one apple, and in a contrary direction on the next. The device is attached by a clamp to the table. In Fiff. 282, the apple is impaled on the revolving fork, and the knife is made to sweep around au- tomatically, as its platform is revolved Apple-Parer. the curved rack and moving the larger cog-wheel which runs the pinion on the fork-shaft. The par- ing-knife and its stock have no motion on each other, but have such a progressive and rotary movement, that, as the apple is revolved, the knife will pass from the stem to the blos- som end of the apple, and adapt itself to the varying form and inequalities of the fruit being pared. The knife is automatically moved away from the fruit after the efi'ective sweep, and resumes its operative position when returned to the starting-point. Ap'ple-quar'ter-er. An implement for dividing apples into ijuarters. A wooden plunger is pressed down upon the apple placed on a central point, and forces it between the four knives. In another form it is a coring-tube with four radial wings. Fig. 284. , Apple- Qitarterer. Ap'pli-ca-tor. A surgical instniment, of form and proportions adapted to its specific uses, for ap- plying caustic, a tent, or other application to a deep- seated part. Ap-point'ments. 1. (Personal.) Accoutei-ments other than arms and ammunition. 2. (Naval. ) The furnishing or equipment of a ship. APPROACH. 126 AQUARIUM. Approach'. In a military sense, either a route by wliicli a fort, fortified town, or otlier military position, may be approached for the purpose of attack ; or the trench or protected road constructed by the besiegers for conveying ordnance, ammuni- tion, and stores, or for marching bodies of men to or from the parallels ; in the latter case approaches may be either excavations, with the earth there- from thrown up as an embankment on the side ex- posed to the enemy's shot, or they may be formed of sand-bags, gabions, fascines, or anything, in short, which will stop a cannon-ball. The works of tlds kind constructed during the siege of Sebastopol in 185-i and 1855 are probably without a parallel in nioil(?rn history, if indeed tliey were ever equalled in the history of sieges. They embraced seventy miles of sunken tienches, and no less than sixty thousand fascines, eighty tho\isand gabions, and one nullion sand-bags were employed to protect the men working in the trenches and at the different batteries. A'pron. 1. A board or leather which conducts material over an opening ; as, the grain in a separa- tor, the ore in a huddle or frame^ etc. 2. The sill of a window or a dock entrance. 3. The floor of a tail-bay. See C.iNAi, Lock. 4. A leaden plate over the vent of a gun. 5. A leathern covering for the legs of the person occupying the driving-seat of a vehicde. 6. The piece that holds the cutting tool of a planer. 7. (Plumbing.) A strip of lead which leads the drip of a wall into a gutter ; a flashing. See Gut- ter. 8. (Shipbuilding.) A timber within the stem of a ves.sel in prolongation of theffccc/wood. It .strength- ens the stem, and attords wood for the reception of the plank of the bottom and the heels of the fore- most timbers. See Stem. A'pron-piece. (Carpentry.) A horizontal piece su)ipurting the upper ends of the mrriagc-picccs or rough-strings of a wooden staircase. A pitching-piece. The carriage which supports the steps is pitched or slanted against it. Apse, Ap'sis. (Architecture.) a. The arched roof of a house, room, or oven. b. The domed semicircular or polygonal termi- nation of the choir or aisles of a church, where the altar was placed and where the clergy sat, in Gothic constnictions. A-qua'ri-um. A vessel containing salt or fresh water in which living specimens of aquatic animals am! plants are maintained ; sometimes called viva- rium or aqua vivarium. From the earliest times animals living in water have been kept alive in small vessels for exhibition or transportation by fre- quently changing the water, yet it is only since the rise of modern chemistry and physiology that the true principles of the aquarium have been discovered. As the air contained in the water is breathed by the animals and loses its vitality, the resulting gaseous product becomes deleterious and must be removed ; this is the office of the plants in the modern aquarium ; these restore the oxygen and abstract the excess of carbonic-acid gas, their func- tion in the subaqueous vegetation being similar to that performed by the ordinary terrestrial flora. But, besides the animals and plants properly pro- portioned to each otlier to maintain the uniform composition of the air in the water, it has been found necessary to add certain animals which feed on de- composing vegetable matter and act as the scaven- gers in this community ; such are the various species of molluscous animals, as the snails, etc. It is of importance to guard against the preponderance of animal life, for an excess of animals over plants in a given space will disturb the balance and lead to their destruction. The demonstration of these conditions is due to R. Wariington, 1850. In some cases wheie the supiily is continuous, the fresh water maintains a healthy condition ; and the same effect has been at- tained by a succession of bubbles of air introduced into and ascending through the water to maintain tlie natural ecpiilibrium destroyed by the animals breathing therein. Agitation of the water produces the same re-srUts more or less perfectly, V)ut tlu' etl'ect is not so pleasing unless it be introduced with scenic devices or machines, such as paddles, wdieels, mills, or moving automatons which require a supply of water to make them constant. In 1849 N. B. Ward giew sea-weed in artifiii.-il sea-water. A great aquarium, one hundred and fifty Fig. 285. Aquarium. feet long and thirty -six feet wide, was constructed in 1860 in the Jardin d'Acclimation in Paris by Alfurd Lloyd of London. The same gentleman erected a magnificent aquarium in Hamburg. Fig. 286 shows an arrangement for the introduc- tion of air for the revivification of the water. It is an air-forcing apparatus consisting of an inverted weighted vessel whose edges are submerged in the Fig. 286. Cutting^s Aquarium. wnter of the reservoir, and which connects by a flex- ilile ])ipe with the interior of the tank. As the in- verted weighted air-holder descends gradually, it AQUATIC BOX. 127 AQUEDUCT. forces air through the flexible pipe into the aijua- rium. The aquarium of the Paris Exposition was a re- markable success, and has given rise to much more ambitious structures. The aquarium of Brighton, Eugland, for instance, occupies ground 715 feet in length, with an average width of a hundred feet. The aquarium proper is divided into three corri- dors. The first is divided again into nineteen bays, which are roofed over with bricks, groined vaulting of red and black alternating with red and bull'. The arches, ribs, and bosses are of Bath stone. The ex- treme length of the corridor is broken most efiec- tively by a central square 55 by 45 feet, the groined vaulting forming a sort of cloister around the square, while the central portion is covered with an elabo- rate ornamental iron roof, partly glazed with antique colored glass. The tanks are arranged on either side, twenty-eight in number, averaging in size from 11 X 20 feet to 55 x 30 feet. The wliole front work of the tanks is of Portland stone, ornamented with appropriate devices of tish, shells, marine mon- sters, and aquatic sj-mbols. Tliese fronts are in- closed Ijy plate glass of great thickness, secured to the stonework by waterproof cement. The area of water surface visible in the rear of the glass is 9 feet wide by 5 feet deep. The light of the corridors is only transmitted through the water, thus affording to the visitor the sensation of being under water without the inconvenience of a wetting. At the eastern extremity of this corridor, whieli is 220 feet in length, the visitor finds before him the entrance to a fine conservatory. Tliis entrance is at the junc- tion of the first and second corridors ; the latter, running north and south, forms right angles with the first corridor. The conservatory is 160 feet long by 40 feet wide and 30 feet high. The orna- mentation of this apartment is in keeping with that of the other parts of the building. It is chielly in- tended for a sort of subterranean promenade, and is ornamented with plants, ferns, small aquaria, etc. Corridor No. 3, which is approached from No. 2, is of the same length as the conservatory, contains twenty tanks, some for fresh-water, others for salt- water fishes. At the end of this corridor are the engines and the store tanks, boiler, retiring and naturalists' rooms, and another flight of steps lead- ing to the terrace. The water for the tanks is supplied, by means of pumps, from reservoirs beneath the floor of the building ; and by an arrangemen„ of pipes and pumping the water is kept constantly in motion throughout the aquarium. The whole cost about § 250,000. A-quat'ic Box. An accessory to the microscope in the form of a shallow glass cell in which algte or aniniiilculffi are placed for observation. A'qua-tint A peculiar style of engraving on metal said to have been invented by St. Non, a French artist, about 1662. Othenvise stated to have been invented by Le Prince, Metz, 1723. The process, briefly described, is as follows : A sur- face of resin is sju'ead upon a polished plate in such a manner as to leave innumerable little interstices between the resinous particles. This surface cov- ering is called a ground, and may be made in two ways, — the dry process and the solution process. the dry process is performed by dusting over the very slightly gi-eased surface of the jdate a shower of tinely powdered resin. The surplus ha\'ing been removed by tapping the plate, which is held in a re- versed position, the particles are caused to adhere to the plate by warming the latter over a lamp, or, what is much better, the moderate diffused heat of a piece of burning paper. In the interstices between the particles of resin the plate is exposed to the ac- tion of acid, of which presently. The solution process consists in dissolving the resin in alcohol and Hooding the plate with it, allow- ing the liquid to run off ; a film adheres to the plate and cracks in drying, leaving innumerable fine fis- sures where the plate is exposed. The design is now placed on the "ground," or it may have been previously etched in ; the latter is now preferred. A wall of wax being erected around the design, it is flooded with dilute acid, as explained under Etching (which see). For copper plate, dilute nitrous acid is used (acid, 1 ; water, 5). For steel, dilute nitric and pyroligneous acid is used (nitric acid, 1 ; pyroligneous acid, 1 ; water, 6). As soon as the lighter tints are sufiiciently bit in, the acid is removed and the plate washed and dried. The light portions being stopped out, that is, covered with Brunswick black to protect them from farther action of the acid, the latter is again applied for the second tint, and so on. The delicate gradations are obtained hy Jioodiny anA feathering, which are nice teclmical operations, requiring skill only at- tained b}' practice, and for a description of which we cannot spare room. This is a cheap and effec- tive mode of engi'aving, and is not estimated at its proper value. The effect produced is like a di'awing in India ink. For different grounds the resin is more or less diluted ; thegreaterthe dilution the finer the gi-ound, that is, the more delicate and numerous are the in- terstices in which the acid acts. A different ground is also obtained by a change of ingredients. Ber- gundy pitch, mastic, frankim^ense, and other resins, give various patterns of grounds, so to speak. Aq'ue-duct. A conduit for the conveyance of water. Jlore jiarticularly applied to those of con- siderable magnitude intended to supply cities and towns with water derived from a distance for do- mestic purposes, or for conveying the water of canals across rivers or valleys. Pocock describes one erected by Solomon for conveying water from the vicinity of Bethlehem to Jerusalem. Tliis was formed by earthen pipes about ten inches in diame- ter, encased with stone and sunk into the ground, and would seem to have confomied to its inequalities, indicating a more advanced state of hydraulic engi- neering in Solomon's time than is commonly sup- posed to have been possessed by the earlier Romans, who were justly famed for their works of this kind, which have never been surpassed in strength and beauty. The earliest account of any aqueduct for convey- ing water is probably that whicli is given by Herodo- tus (who was born 484 B. c. ). He describes the mode in which an ancient aqueduct was made by Eupalinus, an architect of Megara, to sujiply the city of Samos with water. In the course of the aqueduct a tunnel, nearly a mile in length, was pierced through a hill, and a channel three feet wide made to convey the water. The first of the Roman aqueducts (Aqua Ajjpia) was built, according to Uiodorus, by Ajipius Clau- dius, in tlie year of the city 441, or 312 B. c. The water which it supplied was collected from the neighborhood of Frascati, eleven miles from Rome, ami its summit was about one hundred feet above the level of the city. The second (Anio Vetus) was begim forty years after the last-named, by M. Curius Dentatus, and fin- ished by Fulvius Flaccus : it was sup])lied from the country beyond Tivoli, forty-three miles distant. Near Vicovaro it is cut tluough a rock upwards of a AQUEDUCT. 128 AQUEDUCT. mile in length, in which part it is five feet high and four feet wide. Tlie water of tliis ai)ueduct wa.s not good, and therefore only used for the most ordinary ])urposes. The third (Aqua Martia) wa.s supplied from a fountain at the e.vtreniity of the mountains of the Peligni. The water entered the eity by the Es- quiline Gate. Tliis acjueduct was the work of Qiiin- tns Martins, and had nearly seven thousand arches in a course of thirty-nine nules. Tlie fourth (Aqua Tepula) was supplied from the vicinity of Frascati. The tilth (Aqua Julia) was about six miles long, and entered the city near the Porta Esquilina. The si.\th (Aqua Virginis) was constructed by Agri|)pa thirteen years alter the Julia. Its summit, in the territory of Tusculum, was about eight miles from Rome, which it entered by the Pineian Gate. This water still bears its ancient appellation, being called Acqna Vergiue. The seventh (Aqua Alsietina, called also Augusta, from the use to which Augustus intended to apply it for supplying his Nauraachia) was brought from the lake whose name it bears. The eighth (Aijua Claudia), begun by Caligula and completed by Claudius, is about forty miles in length. It enters the eity at the Porta Nevia, near the Esquiline Mount. Tlie quality of the water which this aijueduct supplies is better than that of any of the others. It was built of hewn stone and supported on arcades during seven miles of its length. After a lapse of eighteen hundred years it still continues to furnish Modern Rome with pure and wholesome water. The ninth (Anio Novus, to distinguish it from the second-named water) was begun and finished by the same persons as the last-mentioned. It is the water of the Anio, which, being exceedingly thick and muddy after the rains, is conveyed into a large reser- voir at some little distance from Rome, to allow the mud to subside. The .\equa Felice Is modern, and was erected by Sixtus V. in 1581. The Popes have, from time to time, been at con- siderable pains and expense in repairing and renew- ing the acpieducts ; but the quantity of water de- livered is constantly diminishing. In the ancient eity the sum-total of the areas of the dilferent pipes (which were about an inch in diameter) through which the above iininense c|uantity of water was de- livered, amounted to about 14, 900 superficial inches ; but the supply was subsequently reduced to 1170. The waters were collected in reservoirs called castella, and thence were conveyed through the city in leaden ])ipes. The keepers of the reservoirs were called castcllani. Agri]ipa alone built thirty of these reservoirs during his asdileship. There are five modern ones now standing in the city : one at the Porta Maggiore, Castello dell' Acqua Giulia, dell' Acqua Felice, dell' Acqua Paolina, and that called the Fountain of Trevi. The aim of the Roman aqueduct-builders was to conduct the water along with an equal fall during the whole 2 feet, and at the string course of the second tier 885 feet. The large arch through which the liver passes is 80 feet 5 inches in span, the three on the right side of this are 63 feet, and the smaller ones 51 feet. Those of the upper story are all equal, 15 feet 9 inches in span ; their piers vary in width, and do not come iinniediately over those below. The whole is constructed of freestone, from the foundation to the third course above the cyniatium AQUEDUCT. lL".l AQUKDUCT. was and covering the piers of the upper story. Rubble employed for filling in the piers, spandrels, haunches of the fii-st and second stories. The stones were laid without cement, each being raised by the lewis, the holes for the insertion of was taken to prevent leakage from one into the other, so that the water of better quality might not become deteriorated by mingling with that of infe- SectioQ of Upper Story, enlarged scale. which are still to be seen exactly over the center of g^a^^ty of each stone. The dimensions of the water-way are 4 feet in width and 4 feet H inches high ; the fall through- out its entire length is 2.112 inches per mile, and it is estimated to have been capable of supplj'ing from 14 to 18 millions of gallons of water per day. The entire length of the aqueduct is over 254 miles. The aqueduct of Segovia, Spain, was built by the Emperor Trajan, and is of squared stone laid with- out moitar, and in crossing a valley has a length Fig. 2.8S , Roman Aqueflucts, Julia^ Tepula, and Mania, Aqueduct of Segovia. of more than 2,200 feet ; it is in many places nearly 100 feet high. An elevation and plan are shown in Fig. 288. The waters of the Aquae Julia, Tepula, and JIartia at Rome were conduct- ed through a triple aqueduct, forming three channels, one above the other, as shown in theaccom- panying section ; the Aqua Martia be- ing the lowest, the Aqua Tepula the middle, and the Aqua .Tulia the up- permost of the se- ries. Particular care rior clearness and purity ; to effect this, the bottom of the channel of each wasba.sed upon thick stones passing into the sides of the aqueduct, and care- fully lined with tiles and a coating of cement. Doors from the outside admitted the per- sons in charge to examine the condition of the conduits at any time, and they were requiied to report con- stantly upon their efficiency and state of rejiair. The accompanying illustra- tion (Fig. 2fi0) ..shows one plan adopted by the Romans for con- veying water across a valley. The ac|ueduct was erected by the Emperor Claudius for supplying a palace in an elevated part of the ancient city of Lugdunura (Lyons). The channel-way, both in as- cending and descending, was formed by masonry, tiles, and ce- ment. The work was performed as follows : A level pavement was formed of brick, on which was raised a frame or caisson of tim- ber planks ; against the sides of this, squared stones were laid in regular courses, and their interior filled in with iiibble in a dry state, after which a gi-outing of liquid poured in to cousoliilate the whole. 'Uient was Lime, fine Qdc Lyons Aqueduct. AQUEDUCT. 130 AQUEDUCT. gravel or sand, mixed with a due proportion of wa- ter, formed this grouting. After a sufficient time liad allowed this work to consolidate, the caisson was mounted upon another course or layer of tiles, and similar o])erations to the first took phice. The bricks or tiles used were 21 inches in lengtli, 12 inches in breadth, and lA inches in thickness. The wlinle of the water conduit was coated with cement ; at bottom, its thickness was 6 inches, at the sides H inches. 24 inches from the bottom of the canal, at distances of 30 inches apart, the side walls were stayed with iron ties to prevent their being burst apart. In the ancient aqueduct at Lyons, called at one part of its course Mont de Pile and at another Champonest, the water was brought over eight bridges in the usual manner, and a siphon was em- ployed for conducting it across the ninth. At this point the valley is very deep, and a reservoir was built from which leaden pipes of large size, bedded in the sides of the valley, conducted the water to others laid over a bridge in an inverted curve ; they were then conducted up the opposite side of the valley, and delivered the water into a reservoir at the same level as the first ; from this they were conducted under ground for some distance, and thence, by a bridge of ninety arcades, to another reservoir, from whence it again descended into a valley through similar leaden pipes, crossing a river and ascending tlie other side of the valley, where it was delivered into a reservoir on that side. From thence it was carried, partially over arcades, to a reservoir at one of the gates of the city, from w'hence again it was carried by leaden jiipcs, first falling and again rising until it reached the reservoir from whence it was finally distributed ; in this last instance the pipes were bedded in solid masonry, and not carried over a bridge. The total length of this remarkable piece of work, which certainly seems to combine all the known appliances for conveying water without the aid of extraneous mechanical power, was 13 leagues, and the fall in this distance upward of 350 feet. Wherever the aqueduct was tunneled in the sides of the hills at a considerable distance below the sur- face, wells were sunk to carry ott' any vapors which might accumulate, and to admit light and air ; they also afibrded access to any workmen who might be employed to make repairs or remove accumulated deposits in the channel : these were at distances of 120 feet apart. Perpeiulicular vent-pipes were also erected for ventilating purposes. The walls, where the work was above ground, were two feet thick, and the arches were roofed over to shed rain. The entrance to the aqueduct was through iron doors opening internally. The underground portions were accessible by trajis or man-holes brought up a little above the level of the soil. Pipes, in eases where a very large supply of water is not required, uiuloubtedly possess many advan- tages, and in very broken and rugged localities their use, either alone, or in combination with masonry or brick conduits, along the more level portions of the route, is indispensable without increasing the cost of the work beyond all reasonable bounds ; but it would seem, both from the experience of anti(piity and that of more recent times, that the stone or brick channel into which the air is freely admitted, and to which ready access can be had for the re- moval of im]nirities or obstructions, is, when the engineering difficulties and cost are not too great, preferalile to any other. Tliis of course does not apply to the delivery and discharge of water within cities or towns ; there. metallic pij>es of some kind are indispensable. Cast- iron is the material now universally employed for the larger pipes of this de.scription, called mains, and is perfectly unobjectionable in every respect. Leaden jiipe is very extensively employed in buildings for discharging water, but, unless kept constantly filled, is a very dangerous material, its salts being active poisons. Lining with tin is a good expedient. In China and Japan, bamboos of large size are used to convey water from one point to another. The ancient works executed under the later Ro- man enqiciors for the supply of Constantinople combine the system of aqueducts with the collection and impounding of water by means of reservoirs at the head of the aipieduct. The impouniling res- ervoirs are situate about twelve miles from the city, on the slopes of a range of mountains whii'li form the southeastern prolongation of the gieat Balkan chain. There are four principal acpieducts, one of which conveys the water collected by three separate reservoirs, while the other three are each supplied by its own reservoir. Besides these extensive pro- visions for securing water to the city, tliere are im- mense subterranean reservoirs, one of which, now in ruins, is called the Palace of the Thousand and One Pillars, not because this is the jn-ecise number aup])orting the roof, but because the number is a favorite one in the expression of Eastern hyperbole. This great subterranean cistern is suppo.sed to have been made by the Greek emperors for the pui[iose of storing water in case of a siege or similar calam- ity. Although originally of great depth, it is now nearly filled up with earth and rubbish. It is sin- gular that in the nineteenth century we are reviving in our covered reservoirs, for the purpose of storing water in a state of freshness and uniform tempera- ture, the practices which were followed nearly two thousand years ago by nations whose modern de- scendants are half barbarians. Works of great magnitude were, according to Garcilasso, eonsti-ucted for purposes of irrigation by the ancient Peruvians, previous to the conquest of that country by the Spaniards. On the western slopes of the Andes there are im- mense districts where rain never falls, and which are incapable of cultivation unless watered by artificial means. The Incas caused numerous aqueducts to be constructed for this purpose ; one of these is stated _ to have been 120 leagues in length and 12 feet in' depth, and to have watered a tract of country more than 50 miles in width ; another was 150 leagues in length, travei'sing an extensive province and irrigat- ing a vast and arid district of jiasture laud. The Peruvians do not appear to have advanced so far as the use of bridges or pipes for conducting the water across valleys, — their purpose j>robably did not require it, — but gave their aqueducts a sinuous course, winding around the mountains ami through the valleys with sufficient inclination to allow the water to How freely. The Fren<;h aqueducts referred to in this article are most of them of great magnitude and impor- tance, and the most stupendous work of the kind ever projected originated in France. This was the a(pieduct of Maintenou, which was undertaken in lost and al)andoned in ll5S8, during which tinie 22,000,000 francs are .said to have been expended upon it. It was intended to have brought water from the river Eure at Pongoin to Versailles, a dis- tance of nearly 25 leagues, and embraced an arcade of masonry 16,090 feet in length, comprising three tiers of arches at its highest part. The illustrations (Fig. 291) exhibit to the same scale, — AQrEDL'CT. 131 AQCEDUCT. 1. The PotU du Gard Aqueduct, at Xisines. un- conduit is 157 feet above the river, and is referred der which the river Gardon pa&ses, and ivhicli was i to above, built by the Bomans, possibly by Agripi)a. The | 2. The Solani Aqueduct of the Ganges Canal ; Fig. 291. .* Aqueducts. the area of the water-way is eighty times that of the Pont du Gard. 3. The Eoque/avour Aquiduct, erected by Mon- tricher to conduct the waters of the Durance to Marseilles. The aqueduct for supplying Marseilles with water extends from the river Durance, a distance of 51 miles, though a very hilly country. It comprises 78 tunnels, having a uniteil length of over 12 miles. It has 500 bridges, embankments, and other artificial con.structions. Marseilles lies in a large arid basin, and the aqueduct approaches the edge of the basin at a hight of 500 feet above the level of the sea. Branches extend to and irrigate the area of 25,000 acres, and also supply the city of ilarseilles. The bridge over the valley of the Arc is 1.287 feet in length and 262 feet in hight. It is forujed of a triple tier of arehes ; is said to have occupied from 700 to 800 workmen for seven years, and to have cost S 750,000. The water channel is 30 feet wide at top, 10 at bottom, and is 7 feet deep. It deliv- ers 11 tons of water per second. The aqueduct of Chirk on the EUesmere and Ches- ter Canal iu England is noted as being the first in which iron was employed, the lx)ttom of the water channel being of oast-iron and the walls of masonry ; that of Pont-y-Cysytlte, on the same canal, has the entire channel made of cast-iron arches or ribs rest- ing on pillars of stone. It carries the waters of the canal across the valley of the Dee. It is upwards of one thousand feet in length, consisting of nineteen arches of equal span, but varying in their hight above the ground. The three shown in elevation in Fig. 292 are the high- est, being those which cross the river Dee itself ; the surface of the canal is one hundred and twenty- seven feet above the usual level of the water in the river. The aqueduct itself is a cast-iron trough formed of plates with flanges securely bolted to- gether. This trough is supported upon cast-iron arches, each composed of four ribs, supported upon piers of masoniy. The towing-path overhangs the water, being supported at intervals on timber pillars. Watt's submei^d aqueduct acro.ss the bed of the Clyde was an arricnlated pipe whose joints rendered it flexible, so as to accommodate itself to the shape of the river-bed. It is stateil to have been a success. Fig. 292. Pont-y-Cysyllte Aqueduct. The Croton Aqueduct was commenced in 1S37 and completed in 1842, costing S8,575,000. Its length is 40* miles, 33 miles of which dis- tance it is built of stone, brick, and cement, arched above and below. It has a capacity for dischargin'^ 60,000,000 of gallons per day. It is carried over the Harlem River by pipes laid upon a bridge con- sisting of fifteen arches, eight of 80 feet and seven AQUEDUCT. 132 AQUEDUCT. of 50 fi'ttt sfiaii, I'isiiig to 114 feet above low-water mark. At tlip spot wlieie the Croton dam is constructed, the surlacc-Wiiter of the creek was about 38 feet lower than the elevation vet^uired as a head for the delivery of the water into the city of New York at a .sufficient hif^ht. by going farther up stream a dam of less hight would have been sufficient, but the supply of water would of course have been smaller. The mediiun How of water at thi' dam is about 50,000,000 gallons daily, and the minimum in very dry seasons about 27,000,000 gallons. The water is set back upon the course of the creek by the dam, about si.x miles, forming the res- ervoir, whicli has an area of abovit 400 acres, now called Croton Lake. The available capacity of this reservoir down to the point where the water would cease to flow into the aqueduct is estimated at 600,000,000 gallons, in addition to which tlie re- ceiving reservoir in the city is capable of containing 150,000,000 more when full, which together attbrd a reserve supply of 750,000,000 gallons in seasons of extreme drouglit. In case of necessity other streams might be turned into the Croton River at or above the reservoir, or into the aqueduct. From the dam at the lower end of Croton Lake to the receiving reservoir there is no essential change made in the form of the channel-way, except that, in crossing the Harlem Kiver and a valley on Manhattan Island, iron pii)es are used instead of masonry ; at these places the Fifc'-293. pipes fall and rise again so that they are al- ways full. The channel-way of masonry is nev- er entirely filled, so as to cause a pres- sure on its in- terior .surface. To avoid this, si.\ waste weirs were construct- ed at suitable places to allow tlie water to flow ott' upon attaining a certain level. Fig. 293 is a section showing the kind of masonry used in earth • FiR- 294. excavations. I The foun- j dation is of concrete, the side walls of ; stone, the bottom and sides of the interior faced with lirick, and the top covered with an arch of brick. After the masonry was finished the excavation was tilled uji around it and over the top of the cover- ingarch,gen- Rrick Knnrnlion. erallv to the Earth Excavation. Rock Tunnel. depth of three or four feet, and in deep excavations up to the natural surface. Fig. 294 shows a section in open cuttings in rock. The rock was excavated to the re(|uisite depth and width, and the bottom tilled in with concrete to the proper liight and form for receiving an inverted arch of brick ; the siile walls were of brick bonded with all outer cnsiiig of .stone, built up clo.sely against the sides of the rock. Un the exterior of the rooting arch, and hlling the space between it and the rock, spandrels of stone were built. When finished, the space above the masonry was filled in with earth. Fig. 295 is a section in tunnel cuttings in .solid rock. In hard, sound rock the Fig- 295. natural rock often served as a roof, but when soft, a brick arch was built over the channel walls and the space between its up- per surface and the rock tilled in with well- ramined earth. In some cases where the rock was originally hard, it was found to be- come soft and insecure upon exposure to the air, ren- dering it necessary to arch over the channel-way to support the natural roof. Fig. 296 is a section in earth tunnel cuttings. In dry and compact earth the excavation for the bottom and .sides was made of just suf- Fig. 296. ficient size to re- ceive the mason- ry built closely against it ; the top was maile high enough t • < give room l"i turning the root- ing arch, and when complete the space above it was filled with earth closely rammed. In wet earth the excava- tion was made larger and the top and sides sup- ]iorted by props of timber and plank until the masonry pleted ; the vacant space around it was partly filled with earth. In crossing valleys, the a(|ueduct was supjiorted on a foundation wall of stone, laid dry, and sloping embankments of earth were thrown up on each side of it. .\t intervals of a mile apart, ventilating shafts of stone were erected over the a(|ueduct, rising about 14 feet above the surface of the gi'ound ; every third shaft was provided with a door to aftbrd en- trance to the interior of the aqueduct for the pur- pose of inspection or repairs. Openings two feet S(iuare were also made in the top of the roofing arch "Very quarti'r of a mile ; each of these was covered Earth Tunnel. was corn- then com- AQUEDUCT. IJ AQUEDUCT. by a flag-stone, and its position indicated liy a small nionument projecting above the surface ; these are for the purpose of obtaining entrance or increasing the ventilation if necessary. Where the line of the woik was intersected by streams, culverts were built to allow the water to pass under without injury to the aqueduct. In connection with the reservoir at the dam is a tunnel and gate-chamber. The gate-chamber is not direetlv connected to the dam itself, but is at a dis- tance of upwards of 200 feet. The water is con- ducted from the reservoir to the gate-chamber by means of the tunnel T, which is cut through the solid rock of the hill, having its entrani'e above the dam, its center being about 12 feet below the sur- face of the water, so that the entrance of floating bodies is prevented. In winter, when the reservoir is frozen over, there is no obstruction to the flow of water into the aqueduct, and in summer the water is drawn from a level where it is cooler and purer than at the surface. The gate-chamber has two sets of gates, the one being called regulating gates, R, and the other guard- gates, G, G. The regulating gates are made of gun- metal, and work in fi-ames of the same material, fitted to stone jambs and lintels ; the guard-gates are of cast-iron, working in cast-iron frames, also attached to stone jambs and lintels. The gates are managed by means of wrought-iron rods, having a screw on their upper part working in a brass nut set in a cast-iron socket-cap. The accompanying view (Fig. 297) exhibits a sec- tion of the hill through which the tunnel is cut. showing its entrance into the reservoir, the gate- house and gates, and the point of discharge into the channel-way of the acjueduct. Fig. 297- In the center of the dam and on its ridge is agate- house over a culvert parsing through the dam. This culvert is 30 feet below the surface of the water w-hen the reservoir is full, and has gates opened by rods rising up into the gate-house. When the river is low, the water which is not carried oft' by the aqueduct may be allowed to pass through this culvert, preventing any from passing over the dam. The bottom of the water-way of the aqueduct at the gate-chamber is 11.4 feet below the surface of the reseiToir, and 154.77 feet above the level of mean tide at Xew York Cit)'. The aqueduct is divided into different planes of descent from the gate-chamber at the liam to that of the receiving reseiToir on Manhattan Island, and is as follows : — Length. Descent First plane of aqueduct Second plane of aqueduct Length of pipes across the Har- lem River Difference of level between the ends of tne pipes . Third plane of aqueduct Len-rth of pipes across the Man- hattan Valley Difference of level between the ends of the pipes . Fourth plane of aqueduct Feet. 26,099 72 148,121.25 Miles. 4.943 28.0.53 Feet- 2.94 30 69 1,377..3.3 0,261 10,7.33 14 2.033 2.29 2.25 4,10.509 0.777 10,680.89 2.023 3.86 1.60 1 201,117.42 38.090 43.« The bight of the interior of the aqueduct is 8 feet .5i inches, and the greatest width 7 feet 5 inches ; the interior having a sectional area of 53.34 S(iuare feet. On the first plane the aqueduct is larger, be- ing 2.05 feet higher at the gate-chamber, 2.31 feet higher at 2,244 feet from the chamber, and diminish- ing to the head of the second plane, where it is of the dimensions above stated. The cun'es used in changing the course of the aqueduct are generally of 500 feet radius ; in some- cases a radius of 1,000 feet or even more was em- ployed. The receiving reservoir is located between Sixth and Seventh Avenues and Seventy-ninth and Eighty- sixth Streets in the upper part of the city of New- York. It is 1,826 feet long and 836 feet wide at the top of the external walls of the embankment, having a total area of 37 acres, the area of the water-surface being 31 acres. The reservoir is divided into two divisions by means of an embankment, either of which may be used indepentlcntly while the water is drawn off from the other, in case of repairs, etc. The greatest depth of water in the north division is 20 feet, in the south, 30 feet, and the total capa- city of the whole 150,000,000 gallons. The aque- duct enters a gate-chamber in the south division, where there are regulating gates for discharging the water into eithei' division by a continuation of the aqueduct within the reservoir. The two divis- ions are connected by a cast-iron ])ipe for equal- izing the level of water in each. There is also a waste weir for the escape of surplus water into a sewer. The embankment is of earth, protected on the •utside bv a stone wall four feet thick, the face of which' is laid in mortar: the inside slope has a stone facing, 15 inches thick, laid without mor- tar. From the receiving reseri-oir the water is carried by iron pipes to the distributing reservoir, a dis- tance of 2.17 miles, with a fall of four feet. The dis- tributing reservoir is 436 feet square at the base and 425 feet square at the comers, baring an area of rather more than four acres, and a capacity of I 20,000.000 gallons. The outside walls have openings, so that by enter- ing a door one may walk entirely round the reser- i voir within the walls, giving a greater breadth with AQUEDUCT. 134 ARCH. a given aniouut of material, and affording an o|i|)or- tunity of examining the work for the inirjiose of olmating k'akage, and also preventing water from finding its way to the e.\terior and causing injury to the wall by freezing. This open space rises to witli- in about eiglit feet of the water-line. Inside of the wall is an embankment of puddled earth faced with hydraidic masonry 15 inches thick. From the distributing reservoir the water is dis- tributed over the city by means of cast-iron pipes of from 36 to 4 inches diameter. The total cost of the work was $ 8,575,000, includ- ing the purchase of land, etc., being within live per cent of the engineer's estimate. In this the cost of the distributing pipes within the city is not included. The Washington Aqueduct was built at the ex- pense of the United States government, for the purpose of supplying the cities of Washington and Georgetown with water, and is distinguisheil by some bold features of engineering. The most re- markable of these is the bridge over Cabin John Creek, near the upper termination of the work, the widest spanned stone arch at the time of its con- struction ; it has a span of 220 feet and a rise of 57 feet 3 inches. The bridge over Rock Creek is also a peculiar and noteworthy application of the results of modern science and mechanical skill. The water is carried across this stream (which divides the cities of Wash- ington and Georgetown) by means of two arches of cast-iron pipes of 3 feet 6 inches interior diame- ter, formed of sections with flanges firmly screwed to each other and braced ; upon these are laid a bridge over which the street cars pass, and which serves as a public avenue of communication bet\veen the two cities. The span is 200 feet, and the rise 20 feet. The aqueduct which supplies Madrid with water, and h:is a large surplus for inigation, is fed from the I'iver Lozoya, where it emerges from the CJuavda- rama Mountains. This work was constructed under the superintendence of Don Lucio del Valle, be- tween ISSl and 1858, and is 47 miles in length. The river gorge is crossed by a cut-stone dam, 98 feet in bight, its wings abutting upon the solid rock of the hillsides. The artificial lake thus formed con- tains 100,000,000 cubic feet of water. The cost of the whole work was 57,897,368 francs. The " canal," as it is termed, has seven miles of subterranean galleiies, 4,600 feet of aqueducts, and 8,600 feet of inverted siphons at the crossings of three valleys. The siphon of Bedonal is 4,600 feet in length. The transverse section of the water- way has an area of about 20 square feet, and it dis- charges (i, 600, 000 cubic feet of water per day ; one fifth is required for to\j'n service, the remain- der being used in irrigating a tract of nearly 5,000 acres. The town service has 45 miles of brick culverts about six feet high, and 60 miles of cast-iron pipes. It supplies 35 public fountains, and has 3,000 ])lugs for fire and irrigating purposes. A novel expedient for the support of an aqueduct across a densely wooded ravine was suggested liy Mr. M'Taggart, the resident engineer for the Kideau Canal in Canada. In a part of the country trav- ersed by the canal, materials for forming an ejn- liankment, or stone for building tlie piers of an acpieduct, could not be obtained but at a great ex- pense. The plan consisted of cutting across the large trees in the line of the works, at the level of the bottom of the canal, so as to render them fit for supjiorting a (ilatform on their trunks, and on this platform the trough containing the water of the canal was intended to rest. Ar'a-besque [ar'a-besk]. 1. (An-hUccturc.) A species of ornament, either painted, inlaid, or carved in low relief, employed for decorating flat surfaces. It usually consists of convoluted and intertwined curves, intended to represent foliage, tendrils, and openwork ehei'ker patterns. In a degraded form, vaiious figures of animals, real or imaginary, have been introduced in the at- tempt to make it more consonant with the later taste for florid oniament. The Koran forbids the repre- sentation of the human form, but some have even deviated so far from the original designs of the Arabs as to blend satyrs, sirens, and mermaids in the de- sign. Tills is on a par with the taste which de- grades consoles into caryatides and pillars into atlantes. 2. {Boolbindiixj.) The Engli.sh term for the im- pressed ornamental work on the sides of cloth and leather-bound books. It is produced by the pressure of hot plates or rollers having the }iattern engraved on them. Ar-bao'cio. (Fabric.) A coarse woolen cloth made in .Sanliiiia from the wool of an inferior breed of .sheep, ealleil the Xaoro. Ar'bal-est. A kind of cross-bow used formerly by the Italians, and introduced into England in the thirteenth century. The arrows shot from it were termed qiuirre/s. Ar'bor. (Mnchitury.) a. An axle or spindle of a wheel or pinion. The term is specially used in horology. h. A mandrel on which a ring, wheel, or collar is turned in a lathe. Ar-cade'. A vaulted avenue. A covered pas- sage. A number of streets in London and Paris are thus vaulted over, and are well known to many of our citi- zens ; the Lowtlier and Burlington Arcades of the former city, for instance. As one mode of connecting down-town and up- town of New York City, the arcade sy.stem has been ju'oposed. Even of this, many forms have been suggested. One is to form a sub-way, a main-way, and an elevated railway. Ar-cade' Rail'\»'ay. The upper roadway to he supported by iron columns, and having gas and Fig. 298. water tubes ; the main-way by masonry, through which the sewers and pneumatic dispatch pass. Access to be had to the various levels by ramps and staircases. Arc'bou-tant. An arched buttress forming a lat- eral supjiort Un- the foot or hauncli of another arch. ArcbL The antiquity of the arch, says Wilkin- son, is traced to the time of Amunoph I., who reigned 1540 B. c. He also thinks it jirobable that the chambers of the brick Pyramids at Memphis, erected by tlie successor of the son of ('heo]is, would ARCH. 135 ARCH. prove to be vaulted over with arches, whieh woukl carry back the antiquity of the arch to 2020 B. c. In one of the Egyptian pyramids is an arch turned over three stones which formed a stone arched ceiling Fig. 299. to the sarcoph- agus chamber. The two outer stones were set edgeways and inclined in- ward, having the other placed upon them, forming an arch. Over these stones was turned a brick arch, the ra- dius of which was 6 feet 2 inches, and the span 11 fe-^t. It consists of four courses, and is 3 feet 10 inches thick. The [ stones beneath were 4 feet long, and 15 inches in breadth. At the back the joints were packed with chips, and the whole was grouted with fluid mortar. This tomb is of the time of Amunopli I., 1540 B c The stone arch at Saccara is of the time of Psammeticus II., 600 B. c. The arches of the tombs of Beni Hassan are coeval with Osirtasen II. and the Viceroy Joseph. Arches are found in Chinese bridges of gi-eat an- tiquity and magnitude ; and as before shown, those of Egypt far autedate the periods of Greece or Rome. Arched vaults are found among tlie ruins of Nineveh. A building at Mycente, in Greece, called " Treas- ury of Atreirs, " has an interior pointed dome ol 48 feet diameter, and of about the same hight, the sec- tion presenting two intersecting arcs of about 70 feet radius. The difficulty of working voussoirs has been evaded bv mak- example of Roman workmanship ; it is believed to have been constructed more than five hundred years before the Christian era, and is yet in a perfect state of preservation, still continuing to perform its origi- nal functions. Tliat iiei>ple also used arches as tri- umphal monuments ; the arch of Titus was erected A. 1). SO ; that of Trajan, A. D. 114 ; and of Con- stantine, A. D. 312. The Gothic style, which origi- nated about the ninth century, and soon spread over the whole of Europe, was emphatically the style of arches. Its special characteristics are the i-lus- tered pillar and the pointed arch. The medieval masons treated them with a boldness and freedom unknown to the builders of Ancient Rome. Their constructions display an astonishing amount of practii'al science, and clearly .show that their taste was equal to theii- skill. Lon'g befoie the properties of the catenaiT had been developed by Hooke, it is more than probable that they were known in prac- tice to the old Freemasons who built Henry A'll.'s chapel and other structures of similar and previous date. The span and hight of some of the principal vaulted arched stractures are as follows ; — Egyptian Arch. Breadth. Tarquin I. 1st century 13th " 14th 17th The Cloaca Maxima " Temple of Peace Cathedral of Salisbury " of Amiens Westminster Abbey Milan Cathedral St. Peter's, Rome St. Paul's, London Fig. 300. Arch. ing the beds horizontal throughout, the top be- ingformed of aflatstone. The soffit of each course was then cut to the re- quired angle with its bed by means of a templet ciit to the radius of the vault (Fig. 300). This form of arch is sometimes known as the " Egyptian," and of course is an arch merely in name, the con- structive principle be- ing entirely different, as the stones of which it is c mposed are only subject to vertical pressure. The Greeks did not allow arches to appear m their -visible architecture, but used them for covenng drains and the like, as in the temple of the Sun at Athens and that of Apollo at Didymos. It wa,s, liowever, contrary to their architectural principles to admit any but straight lines into any visible part ol a building, except, perhaps, as mere ornamentation, thus sacrificing in many instances convenience to secure that severe simplicity of outline by winch their public structures were i-haractenzed. Ihe Romans made very free use of them. The Cloaca Maxima, or Great Sewer, of Rome, is the oldest known For examples of arches used in bridge construc- tion, see Bridge. The term "arch " in its widest signification, is com- monly understood to mean almost anything of a curved shape employed for the purpose of bearing weight or resisting pressure, but in its more restricted mecdianical sense may lie defined as a collection of wedge-shaped bodies termed vovssoiis or arch -stones, of wliich the first and last at each extremity are sustained bv a support or abutment, while the inter- mediate ones are held in position by their mutual pressure and the adhesion of the mortar or cement interposed between them. The center voussoir a, in the highest piart, or crown, of the ^ig. 301. arch, is called the keystone. The in- ferior surface of the arch, bdfe c, is the intrmhys, or sojfit, but this lat- ter term is some- times restricted to that part of the under surface in the immediate vicinity of the keystone, or crown. h d, c c, are the fli()ik:i of the arch. The exterior or top surface is called the cdrados, or back. The points, be, where the intrados meets the alnitments, are called the sprinqings : their horizontal distance apart, the ■■ipan ; and"the distance, ;//, from the center of this to the center of the intrados, the ri^e or height of the arch. The simplest, as it is the earliest, form of arch, is that of a segment of a circle, generally less than a semicircumference, such as is found in the works of the Romans. The Gothic architects about the tenth century originated the pointed arch, formed by two arcs of circles described from dittcrent centers, and meetiiigat the crown. Three and four centered arches were iiSroduced into the later Gothic architecture. Arch. ARCH. 136 ARCH. Three- Centered Arch. Fig. 303. In the three-ceiiterjil !|ipiPIfflliP'flffl!(lrf|!l tlH-benlorthe CLZ ' ' IS was fornu'd by the cor- ri-s]ioiiding opposite mcs of one circle having its center in a line perjien- ilicularly beneatli the ciowu of the arch, the ii]i- per opposite sides to the crown being described with equal ladii, greater than the radius of the lower part, from centei's at equal distances on each side of the perpendicular passing through the crown flf the arch. The four-centered areh was, as its name imports, described from four centers, the two lower centers being perpendicularly under the two upper ones ; from the latter are described the lower parts of the arch near the risings, and from the former, with greater radii, the ujqier parts to the crown ; of this form is the Tudor arch, bear- ing somewhat of a resem- blance to the ellipse. The elliptic arch is employed largely in bridge building and in the construction of vaults, drains, etc. In Fig. 304 are shown some of the fomis of arches employed in architecture. a. The Semicircular arch, de- scribing half a circle. b. The Segment areh, struck from a point below the spring- ings. c. The Elli2itic arch is not always truly elliptical, but is sometimes formed by the com- bination of the arcs of several circles. (/. The Slillcd arch rises from points below its center. e. The Horseshoe arch is pe- culiar to the Moorish or Arabic style of architecture. Various styles of pointed arch- es were employed by the Gothic architects, as shown in Fig. 305. a. The Equilateral arch ; so termed because the two spring- ing points and the crown of the ' intrados form an equilateral triangle. b. The Lancet arch is mon- pointed than the e(juilateral arch ; and c. The Prnji arch less so. (l. The Srepni'ntal Guf/rianvh is composeil of two segments of circles meeting obtusely. c. The Ogee arch was intro- duced at a later period of Gothic architecture. /. The Tudor style prevailed during the close of this most graceful order, and wassonamed from the then ruling family of Forms of Arches. the English dynasty. It has Four- Centered Arch. Fig. 304. I a much flattened arch, low njoldings, and a pro- fusion (if panelings. Fig. 305. Fig. 306. Gothic Arches. Foiled Archts. Foiled arches, Fig. 306, are so called from the com- partments, imitating the foils of a leaf, into which they are divided : as, — a, b, c. Trefoils, d. Cinque/oil. p. Poll/foil. The latter is princijially met with in Saracenic and Komanesque buildings. The Flat arch (Fig. 30") is very fcuerally em- ))loyed in doorways, fireplaces, and window s of build- ings; its inti ados has no curve, though the vous- Fig. 307. soirs are arranged so as to radiate to a center, anil are laid in parallel courses ; where any con- siderable pressure is to be resistecl, it is usu- ally supjioited by hori- zontal bars of iron or wood laid across the opening and having their ends supported in the Flat Arch. wall on each side. In some examples of old date the voussoirs aie held up by indented joints which fit into each othei'. In this form of arch it is Tnanifest that almost the \ / \\ll ih i ARCH. 137 ARCH. Fig. 308. Fireplace of Coniijgsburgh Castle, whole jiressure i.s vertical, and that the arch is suj; ported principally by the cohesion of the parts ; so that it cannot be used for cov- ering any but narrow openings. As at present employed in brickwork, its princi- pal use is to relieve the pressure ou a beam or lintel below it. Oblinue, generally called skew, arches have their axes oblinue to their faces, and on account of the difficulty of their con- struction are seldom employed, unless in railroad bridges where the direction of the line of the road renders it necessary to cross streams obliquely to their courses. In such cases it is necessary that the piere should be parallel to the current of the stream, in order to offer as little resistance as possible and aft'ord a free passage to the water. A bridge arcln-il in this manner is said to have been built near Florence as early as 1530, but their general introduction dates no farther back than the era of the commencement of railroad construction, about or a little previous to 1830. The ordinary method of building a skew arch (Fig. 390) IS to make it a portion of a hollow cylinder, the voussoirs being laid in parallel spiral courses, and their beds worked in such a manner that in any see- I The of spirals intersecting at light angles the coursing joints, or those which di- vide the stones of each course, so that the voussoirs are rectangular on the soffit, except those i|Uoins or voussoirs on the faces of the arch where the sec- tion exhibited is elliptical. In Fig. 310, instead of radiating the bed-joints from the centei- of the I'ylin- der, they are made perpendicular to the curve of the soffit on the obliipic sec- tion. Of the parts of an arch, — The top is the extrados, or hack. The under-side the in/mdos, or soffit. The line from which it commences is the sprimjing line. The stones of the arch are voussoin. The lower one on each side is a spring- er, or rein. middle one is the keystone, and the course Fig. 310. Skero Arch. tion of the cylinder perpendicular to its axis the lines formed by their intersection with the plane of section shall radiate from the axis of the cylinder. In this mode of construction the soffit of each stone will be a portion of a cylindrical surface, and the twist of the beds will lie uniform throughout the whole of the arch ; so that we have only to settle the amount of the twist, and the stones can then be worked with almost as great facility as the voussoirs of an ordinary arch. The heading joints, or those which divide the stones of each course, are portions Skew Arch. the key-course. The upper portion is the vertex, or crown. Midway between the croimi and the springings are the haunches, or flanks. The. sjiringers, or reins, rest on imposts, abutincnts, or piers. The extreme width is the span. The rise of the curve in the center is the versed sine, or rise. The space between the hnunch and the outscrib- ing rectangle is the spandrel. The joints between vmissoirs are the abreii- voirs ; which are perjiendicular to the surface of the soffit. The exposed vertical surface is the face. An Annealing Arch is the oven in which glass is allowed to cool gradually. See An- nealing. An Arabian Arch is one of horseshoe shape. The diameter is less at the springings than above. A Basket-handle Areh is a three-centered, low-crowned arch. A Blind Arch is a closed arch ; one which does not penetrate the structure. Commonly employed for mere ornamentation, to make one face of a building correspond in character with an- other front where there are actually arched openings. A Catenarian Arch is one in the form of an in- verted catenary curve, or that which a chain sus- pended at each end naturally assumes, A Compound Arch has an archivolt receding in steps ; giving the appearance of a succession of re- ceding arches, of varying spans and versed sines. A Concentric Arch is one of several courses whose curves have a common center. Common in Normau and Saxon architecture. ARCH-BOARD. 138 ARCHED BEAM. A Diseharfjiny Arch is one wliicli is formed in a wall to protect a space beneath from the superin- . cumhent \veif;ht. An .Ircli 11/ Eqiti/ihrium is one in which all parts are of .siniilai' strength, and the whole capable of standing without abutments. An .-trch of Equipollcncc is one in which the voussoirs are sustained by mutual opposition ; the thrust of the crown being transferred from one stone to another till it reaches the abutments. A Furnace Fig. 311. Arch is one which spans the fire-cham- % ber and sup- Y, ports a battery % of kettles ; or » it may form _V, the ceiling and — ^ roof of a metal- lurgic furnace, ^ ^ — a inuldlincj furnace, for in- m///////////'m/////m W/WWmM stance. Furnace Arch. A Groincd Arch is one in- tersected by other arches cutting across it trans- Tcrsely. The point of junc- tionisa;/roi)t. An Inflect- ed Arch is a reversed or in- verted arch. An Invert- ed Arch is one with the crown down- wards, as in the rioor of a tunnel, the space beneath an opening in a foundation- wall, etc. A Lancet Arch is a narrow peaked arch, which was much em- ployed for windows during the prevalence of the Gothic style of architecture, known a.s Early English. A Laminated Arch is one made of successive thick- nesses of planking, bent into shape, and secured to- gether by treenails or otherwise. See Arched Beam ; Laminatkd Auch. A. Rinii/iiuit Arch is one whose abutments are on an inclineil iihine. A lielieriiig Arch is one on the spandrel of an arch, to distribute and limit the pressure. A Skene or Scheme Arch, is a circular arch not over 180°. A SliCW Arch is one whose line of direction is oblique with its abutment. See Figs. 309, 310. A Straujht Arch is one built with voussoirs, which give a level intrados, used as the head of an aper- ture in a wall. A Splayed Arch is a funnel-shaped arch ; one whose two end sections are unequal. A Twecr or Tuyire Arch is an arched opening in a furnace-wall at which the blast-pipe enters. A Tymp Arch is the arched opening at which the metal is discharged from a smelting-furnace. 2. ( ifin inij. ) An unworked portion of the ground. Arch-board. {Shiphiiildiny.) The part of the stern over the counter, under the knuckles of the stern timbers. Arch-brick. A compass brick, or one of wedgo .sli;!]"'. Arch-but'tress. A flying buttress ; reaching I'roni the outci' wall of an aisle to the clear-story of the nave to form a lateral support against the thrust of tllc iclof. Arched Beam. (Carpentry.) A beam cut, bent, or built into an arched form to support a structure, as a ceiling, rouf, or viaduct. One form of the arched beam is exeniiilitied by the roof of tlie dining-room of the < 'haiterhou.se School, London (Fig. 312). This murli-perverfed charity is well housed, and the roof of the refectory is formed with circular ribs in four thicknesses of 1^-inch deal four inches wide, with saw-cuts half an inch in depth on the under sides, and put to- gether with murine (jlue, on a cradle center. The dottftl lines show the collars, which are dovetailed one inch into the sides of the principal rafters. The principal rafters, being five inches wide, project on one sidi' an inch before the face of the circular ribs, which are only four inches wide. On the collars rest the jiurlius supporting the rafters. The ceiling joists are spiked uji to the circular ribs. The five main arches of the Ousebourne Viaduct of the Newcastle, North Shields, and Tyuemouth Railway, England, are built of arched beams ; three Fig. 312. Roof over Dinin^-Rooni at C/iarterlwuse School. of these have a s]ian of 116 feet each, and the oth- ers have 114 feet s|ian. The bight of the rails above the lied of the stream is 108 feet, and the width of the viaduct is 31 feet, — 26 for a double line of rails, and 5 for a foot-path. At each end of the viaduct are two arches of masonry, and the total length is 918 feet. The two middle piers are erected ujion piles from 21 to 27 feet in length. All the ]iii'rs are of masonry, and tapeied upward, the principal being 21 feet wide between the foot- ings and 15 feet at the springing of the arches. The piers are continued upward, of reduced dimen- sions, to the level of the roadway, the whole of the five main arches, spandreling, and suiiei-structure being formed of timber. The radius of these arches is 68 feet, and their rise or versed sine about 33 feet. The ribs forming the arches are compo.sed of planks of Kyanized Dantzic pine, the lengths of which vary from 20 to 46 feet, by 11 inches wide and 3 inches thick. The thickness of each rib is made up of fourteen planks so bent as to form an arch, and laid together so as to break joint both transversely and longitudinally. They are fastened together by oaken treenails, li inches in diameter and 4 feet apart, each treenail perforating three of the planks. Between each joint in each direction is placed a layer of strong brown paper dipped in boiling tar. ARCHED-BEAM BRIDGE. 139 ARCHED-BEAJI ROOF. The s]iandrels are fonueil of trussetl framing, and the platform of the roadway, wliich is coniposed of 3-ilich planking, is supported upon transverse beams laid 4 feet apart. The platfuriii is eovereil with a composition of boiling tar and lime, mixed witli gravel in applying it, and thus forming a coating impervious to water. The arched beam lias been very extensively used in tlie timber bridges of the United States. See WiiiiuEN P,i;ir>r;E ; Ariiied-Beam Kuuf. Arched-Beam Bridge. A bridge whose span eitlier consists of a compound beam, or one in which such a beam forms one element in the truss, as in many of the wooden bridges of the last century and the present. See Wooden Biudge. Compound arched beams of iron are also becoming common, and many beautiful bridges are now made on tliis principle. See previous article. The arched beam is now a favorite foim of bridge. Angle-iron of varying cross-section is freely used. See Ii:iiN Bridge. Arched-Beam Roof. In the sixteenth century Philibert de Lorme, a French architect, invented an Kg. 313. Fig. 316. De Lornie^s Arched Beam. arched beam (Fig. 313) made of pieces of timber which were cut into short arcs of the reipiired circle, placed edgewise, and bolted together, lireaking joint. Several roofs in Paris and London are, or were, of this construction. It was a disadvantage of this plan that the pieces were necessarily short, as they would otherwise pre- sent a cross grain to the strain. The largest roof of one span, in its day, was that of the Imperial Riding-House at JIoscow, built in 1790 Fig. 314 Imperial Ridtn^-House . (Fig. 314). The span is 235 feet. Tlie members of the arched beam are notched together (Fig. 315) so as Notched Arch-Beam. to prevent slipping on each other. The ends of the arched beam are prevented from spreading by a tie- beam, and the arch and tie are connected together by vertical suspension-rods and diagonal braces. Colonel Emt's arched beam (1817) is constructed on a principle differing from both of the foregoing (Fig. 316>. The ribs in this roof are formed of planks bent round on templets to the proper curve, and kept Ifc^missj from separating by iron straps, and also by the radi- ating stmts winch are in pairs, notched out so as to clip the rib between them. The principals, wall-posts, and arched rib form two triangles, firmly braced together, and exert no thrust on the walls ; the weight of the roof, being thrown on the walls at the feet of the ribs, and not at the pole plate, peimits the npjier jiortion of tlie walls to be comparatively light. The Colonel erected a roof of tliis desciiptinn in 1825 at Manic, hear Bayonne. The principle has been extensively adopted in wooden bridges in the United States and in Eu- rojie. See Wocidex Bridge. The illustration opposite represents the roof of the Union Passenger Depot of the Xew York and Harlem Raihvay, projected by Commodore Vaiuler- bilt, and constructed from the designs of J. C. Bnek- hout, C. E. The roof is 652 feet long and l!i9 feet 2 inches between walls. It is supported ujmn 32 semicircular trusses, which are spaced 20 feet 4 inches between centers, exteniiing from a point 2 feet below the rails to an elevation of 94 feet from the springing line to the extrados of the arch. Each truss has at its foot two tie-rods 2J inches in diam- eter, with a tuni-buckle at the mid length. The pitch of the roof is formed by rafters secured to tlie top chord of the arch. The trusses weigh about forty tons each, and were raised in sections by means of a movable staging 80 feet high, 1 60 feet long, and 30 feet wide, moving on ways, and shifted along step by step as the work of raising the trusses progressed. About 8,000,000 pounds of iron were used in the structure, 10,000,000 bricks, 20,000 barrels of cement. The car-house is lighted through three skylights, extending over the entire length of the roof, — one on the center, double-liitched, and a single one on each side of the center, and having altogether 80,000 square feet of glass, — nearly two acres. The north end is closed by an iron front, the south end by the building containing the principal offices of the Company. I The roof covers nearly three acres, the station it- ARCHED BUTTRESS. 140 ARCHITECTURE. self about four aures. The station is designed for the u.seof the Hudson River, Harlem, N. Y. Central, and N. Y. and Ni-w Haven Railways, having lines of rail for eai^h coinpany, besides tliose for the Fourth Avenue horse-ears whieh run into and to and from this station, which was opened for traffic October 7, 1871. The gas-burners of the building are lighted at night by electricity ; 25,000 feet of electric wire being used, and 20,000 feet of gas-pipe. The 144 steam-radiators are heated by 15 miles of steam-pipe. The roof is ventilated by six lines of ventiUiting slats 6 feet high and 8 inches wide, with a Z-shaped interval between the slats. The roof of the St. Pancras Station of the Midland Railway, England, covers nearly foiir acres. The roof had at the time of its erection, and may yet have, the widest span of any in existence, 240 feet, and the space beneath is unbroken by ties or braces. Its style is subdued Gothic, with segments meeting at its crown. The roof springs from the platfoiin level, the principal ribs each having the form of a four-centered arch, the radii of the curves being 57 feet and 160 feet respectively. The two central curves — those of 160-feet radius — meet at an an- gle in the center at a hight of 96 feet above the platform level. The length of the roof is 690 feet, with a clear span of 240 feet, covering five platforms, ten lines of rails, and a cab-stand 25 feet wide, thus making a total area of 165,600 square feet. Its hight at the ridge is 125 feet above the level of the road. There are twenty-five principal ribs in the roof, 29 feet 4 inches apart from center to center, and each weighing about 50 tons. The station walls rise, behiml the spring of the principal, the space at the top being filled in with open ironwork. The roof is glazed about 70 feet on each side of the center, and the remainder is covered with slates. The transverse girders which support the floor of the station take the thrust of the roof. They are connected so as to form continuous girders across the station, and rest on the walls of the 174-feet story beneath. Besides being tied to the girders, the feet of the ribs are each secured by four 3-inch bolts to an anchor-plate built into the wall and stronglv fastened. Arched But'tress. A flying buttress, or arc- honfinit. Ar'chil. The extract of Orchilla weed, used for dyeing, \isually evaporated so as to form a solid mass like indigo, i'alleil also Oixhi/ and Cudbear. Ar'chi-me-de'an Drill. A drill whose stem consists of twisted pinion wire, or a core having steep spirals. A nut with internal oblique grooves is re- ciprocated on the stem and rotates the latter. A Persian Diiii.i. (which .sec). Ar'chi-me-de'an Fro-pel'ier. A propeller con- sisting (jf a continuous spiral vane on a hollow core running lengthwise of the vessel. It is an amplifica- tion and extension of the screw. Figure 317 shows it in horizontal and transverse sections. See Screw Pkofei.i.eil. Ar chi-me-de'an Rail'way. A form of railway in which a continuous shaft rotates on pillars erected between the lines of rail, the shaft haring a spiral rib which acts as a screw upon a pedestal below the car to jiropel it .along the track. Ar'chi-me-de'an Screw. The invention of Ar- chimedes when in Egypt, about 260 B. c. It consists of a hollow in< lined screw, or a spiral pipe around an inclined axis ; the lower end is submerged in the water and the u])per end discharges. Strabo refers to a water-raising machine of this kind, used to supply the garrison of the Memphite Babylon, on the Nile, and worked by 150 men. Fig. 317 Archimedean Propeller. it was also used as a draining pump by the Tur- detani of Iberia in the time of .Strabo. This was the country of the Guadalquiver. See Screw, Archimepean. Ar'chi-tect'ure. The classic orders are five : Doric, Lmu; and Corinlhirin (Greek-); Tuscan and Composite {Roni'in). The more modern is Gothic, which has several varieties : Anglo-Roman, B. C. 55 to A. D. 250 ; Aniilo-Sfuron, A. D. 800 to 1066 ; An- glo-Norman, 1066 to 1135 ; Early English or Point- 'ed, 1135 to 1272 ; rure Gothic, 1272 to 1377 ; Flor- id, 1377 to 1509 ; Elizabethan, 1509 to 1625. The subject is copiously and admirably treated in niiiny excellent works. Its interest in a work of this char- acter is not as an art, but as requiring machinery to hew and shape the stones, construct the fouinla- tions and the roof, and also calling for ingenuity in providing the building with its material acce.ssoriesfor safety, viMitilation, warmth, light, and convenience. The following are dates assigned by some authori- ties for the buildings mentioned : — The Pyramids . (about) B. C. 1500 Memnonium ..." 1350 Solomon's Temple ..." 1004 Birs Nimroud, ..." 900 Jupiter Capitolinus . . . " 616 Parthenon . . . . " 438 Pantheon . . A. D. 13 Coliseum . . . . " 70 St. Sophia . ..." 532 Mosque of Omar, at Jerusalem " 637 Caves of EUora ..." 700 St. Peter'.s, Rome ..." 1626 St. Paul'.s, London . . " 1710 The tent is the original of the Chinese style. The care is the original of the Egyptian. The log cabin suggested the Grecian. The aven ue of trees the wondrous Gothic nave. The possession of iron and various facilities of ARCHITONNEEE. 141 ARGAND GAS-BURNER. work have .yet inspired no one. Some are anxious to build iron liouses as much like stone as possible ; the most ambitious attempt is an immense barn at Sydenham, England, — an engineering success, but not a work of inspiration. The Egyptian capitals were the prototypes of those of the Grecian and Roman orders ; and the various ceramic works of the Greeks and Etruscans were strangely like those of the Nile people. The opening of the Egyptian ports by Psammeticus, 670 B. c, was fortunate for the nations on the northern shore of the Mediterranean. For Specific Inde-x of Apxhitecture, see M.\son's A.ND Br.RKL.-lYEll's WoKK. Ar'chi-ton-nere. A name for the Ste.\>i Gun. Ar'chi-trave. (Aixhilecture.) That portion of an entablature which rests upon the columns ; the hntcl. {Carpcittrii.) The molding around a doorway or window. The respective portions are known as the iransoemc. arr-hiiravc, and cDxhilravc jambs. Ar'chi-volt. {Architecture.) o. A molding run- ning round the face of an arch. b. The inner curve formed by the voussoirs or arch-stones. Arch'-stone. A wedge-shaped stone used in an arch ; a voussoir. In some fui'naces the chamber, or an opening thertinto, is covered by a flat aslilar, which is called an arch-stone. Arc'o-graph. An instrument for describing arcs of circles without the use of centers. A thin and pliable strip of metal whose ends Fig. 318. are attached to the wooden bar may be sprung into the required shape and then fastened by set screws. Unless the stock have means for extension and contraction, the range of arc which may be de- scribed will he but limited. The device is susceptible of many varia- tions, and is useful as a templet or marker for many pui'poses. Arcograpli. A-re-om'e-ter. An instrument used by the Spanish Saracens A. D. 1000. It had a bulb and stem similar to a hy- drometer ; floating in liquid, its stem was more or less submerged by the changes in the density of the liquid due to changes of the temperature, and thus constituted a thermometer. Nicholson's areometer consists essentially of the funnel a, the cylinder b, rod c m, and the table or plate d. The instrument is so arranged that when set in distilled water and a definite weight laid upon (/, it will sink to a mark m made on Fig. 319. the rod. To deteiTnine the spe- cific gravity of a mineral, it is laid on the plate el, when it will of course depress the instrument in the water. Additional weights must be added to bring the mark 5/1 to the level of the water, and the amount of these subtracted from the standard weight already referred to will be the weight of the mineral in the air. Call this weight p. Remove the mineral from the plate, and place it in the funnel or hollow cone a ; immersed in the water the areometer will not sink quite to m, say about to c, , the body losing in water an amount SA' of weight equal to that of a quan- Xicholsons Artom. titj' °^ ^''^ter of precisely the same etiT. volume with itself, that is, equal to that of the water displaced. Additional weights are now to be laid on d until the level ;/( is again reached. This amount, which we will call p', ex- presses the weight of an equal volume of water. We have thus ascertained the weight of precisely equal volumes of water and of the mineral, and as water is the standard taken, -^. will express the ratio body. Fig 320. of the two, or the specific gravity of tlie Thus, .(,■ : 1 : : p : p', and .<.■ = -j-,. The areometer of Pappus, the Greek philosopher contemporary with Theodosius the CUeat, A. D. 379-395, is described by A 1-Khaziui the Saracen, an eminent writer of the twelfth century, the author of the "Book of the Balance of Wisdom," and sus- pected to be identical with the great Al-Hazen, whose celebrity is associated with the Cordovan period of Spanish history. It was a graduated brass tube which floated vertically in liquid and indicated by the line of submergence the degree above or below the " eqtiator of ecpiilibriuni," the specific gi'avity of the matter weighed. The surmise of Chev. Khanikoff, indorsed by Dra- per, that Abu-Jafar Al-Khazini and AI-Hazen were identical may be correct. They were certainly con- temporaries, but the former, who.se name it is impos- sible to find in any other part of the Persian an- nals, fails in some respects to answer for 'Abu-'Ali Muhammad Bin 'al-Hasan 'Ibu 'al-Haltham, said to be of Basrah. The book referred to above as the writing of .A.1- Khazini was composed, as is seen in the Dedi- cation, at the court of the Salji'ike Sultan Sanjar, who reigned over a large part of the ancient Khah- fate of Baghdad from A. D. 1117 to 1157. The areometer of Pappus is very similar to the Volumeter of Gay Lussac. G.AY Ll'ssac's scale areometer consists of a cylin- drical glass tube in the lower part of whicha ball his blo^^■n, and, being continued, finally terminates in another ball c. The latter is filled with shot or mercury, to cause the in- strument to sink vertically in distilled water to a certain point, the zero. The .specific gravity of a liquid is ascer- tained by the depth of depres- sion, itsweight being equal to that of the liquid displaced. It is a fonn of hydrometer. A-re-o-stylos. Aninter- coluuiuiation of four diam- eters width. Ar'gand Gas'-burn-er. The Argand Gas-burner has a circular series of holes on the upper edge of a cylindrical chamber, having a central aperture to allow access of air to tlie inside of the flame. The jets from the series of holes unite to form a cylin- drical flame. The holes are aboiit one sixth of an inch in diameter, and when there are ten holes in the circle, tin middle opening will be four tenths of an inch in diameter ; with twenty-five open, ings, the central aperture will be about one inch in diameter. The following formula is given for the number of holes, central ajierture, hight of flame without smoking, and appropiiate size of chimney : — 1' r^/ ^^ Gay Luxsac'S Areotneter ARGAND LAMP. 142 ARGENTINE GLASS. No. of • Apertures. 10 15 20 25 Central Hight of Diameter of Glass Openiug. inch. M Flame, ioch. 3 H 2 Chimney. inch. s iTT 1-2 TTT 18 IW Iff Fig 322. 321 the lowi'i' section of the burner has an orifice for the gas, which is more or less obstructed by the end of a screw whii'h is either turned directly by hand, or, when rertical and inclosed within the burner, is turned by a lever projecting through a slot there- in. Ar'gand Lamp. Invented by Argand, a native of Geneva, about the year 1784. It consists of two concen- tric cylindrical tubes between which is fitted the annular wick used in this peculiar burner. The aunulus inclos- ing the wick is closed at the bottom, and communicates, by a pipe, with the oil reser- voir. The interior tube being open, free access of air is allowed to the inte- rior and exterior of the flame, insuring more eij^ual and perfect combustion. In a round solid wick, burning any of the fatty oils, such as sperm, a large proportion of the carbon, which in that class of oils is gi-eatly in excess of the hydro- gen, escapes unconsumed and is wasted, rising in the form of smoke. The annular wick has double the surface of a solid one of the same diameter exposed to the contact of the atmosphere, and as the flame is also thinner its temperature is more unifonn, and the vapor from the center of the wick is consumed equally with that from its exterior. The com- bustion is also greatly aided by the draft caused by the glass chimney, continually bringing fresh supplies of oxy- gen in contact witli the flame and protecting it from currents of air. The chimney was the invention of L'Ange. Argand died in 180.3. A French mechanic named Carcel patented an improvement in 1800, in which the oil is pumped from the reservoir to the wick by ])ower derived from a spring or by the ascending eoi- umn of air above the chimney. This is called the Mcchaiiiciil Lamp, and is used in the large lamps for the Dioptric system in lighthouses. The Argand burner as modified by Fresnel for the Dioptric system in lighthouses ha,s four concentric wicks, the outer one 3J inches in diameter, and the gi'eat heat produced is carried off by two means, — overflowing the wicks with oil, ami by means of the ventilator devised by Faraday. Tlu- oil in super- abundant quantity is pumped into the wick-tubes and flows over the top. The ventilator is a tube having several sections, the lower portion of eaidi being flaring, and receiving the upper end of the section below, which entei-s it a short distance. The top of the lamp-chinmey enters the lower section and pi'oduces a great tlraft. The Argand lam]) first made effective the Catop- tric system for lighthouses. Argand Lamp. The annexed engraving shows the lamji in its lower position, withdrawn from its place in the focus of the paraboloid reflector a for trimming, b is the bum- Fig- 323. er, and c a cylindrical foun- tain containing twenty-four ounces of oil. The oil-pipe, burner, and fountain are con- nected to a frame d, which is movable in a vertical direction upon guide-rods e /, by which it can be let down by simply turning the handle g. An aperture of an ellip- tical form, measuring about two inches by three, is cut in the upper and lower part " of the reflector, tlie lower serving for the free egress and ingress of the burner, and the upper, to which the copper tube /( is attached, serving for ventilation ; i shows a cross-section and a back view of the main bar of the chandelier or frame on Argand Lamp. which the reflectors are ranged, each being made to rest on knobs of brass, one of which is soldered to the brass band /, that clasps the exterior of the reflector, m is an oil cup to catch drii>. A frost lamp is placed at this point in winter to keep the oil in the wick-tube in a flowing condition. The tubular wick -burner (Fig. 324) has a wa- ter-chamber B C" interposed between the wick- tube and the oil-res- ervoir, soastoprevent the heating of the contents of the lat- ter. The wick occu- pies an annular s[iace formed by two con- centric wicks. M is the deflector jilate, and C I a. frustrum to reflect upward the heat which ri'aches the inside of the tube. G" is a perforated floor to prevent the con- duction of flame, on the principle of Da- vy'ssafety-lamp. The water has an overflow down the central air- tube. A' is the base ring for the chimney. Ar-gent'alMer'- cu-ry. .Silver iunal- gam. Ar'gen-tan. An alloy of nickel cop- per and zinc. Albata sect. Ar'gen-tine. Wljite Ar'gen-tine Glass. havins the sheen of Fig. 324 Dopp^s Argand Lamp, Ger.m.\n SiLVEii iwhich metal coated with silver. An ornami'iital glassware ilver. It is the invention of Apsley Pellatt, and is formed by inclosing delicate white Argentine iucru.stations of dry porcelain clay with solid and transjiarent glass. The dry figures are placed on a red-hot bulb of flint glass and innnediately covered with a thin layer of very fluid glass. ARGEXTOMETEH. 143 ARITHMOJIETER. The exterior layer is polislied, and gives a silvery brightness to the wliite figure. Ar-gen-tom'e-ter. A graduated tube used for ascertaining the amount of silver in a solution by the admission of a definite bulk of chloride of sodium sohition. Ar-gen'tum Mo-sa'i-cum. An alloy, or rather amalymn, of tin, bismuth, and mercury, used for coloring images of plas- ter of Paris. Argcntuiii Miisivum. Ar'gil. Potter's clay, from the Latin argitlii : white clay. Ar'go-sy. A merchant-ship of the Med- iterranean ; specially of the Levant. The tenn is now antiquated. A'ri-es. The battering-ram, so called be- cause the metallic head of the beam was sometimes fa.shioned like the head of a ram. As a means of battering walls it is said to have been invented by Artemanes of Cal- zomene, a Greek architect, about 441 B. c. It is de- scribed by Josephus, who states that it was some- times supported on the shouldei-s of men who ad- vanced on a run ; at other times it was' slung from a frame, and operated by ropes. Philip of Slacedon is said to have been the first to place the frame on wheels, at the siege of Byzantium. Plutarch informs us that Marc Antony, in the Par- thian war, made use of an aries 80 feet long. Vi- tnivius says they were sometimes 106 to 120 feet in length. A-rith-mom'e-ter. An instrument for assisting in calculating. The most ancient form is the Aba- cus (which see). This has a series of wires, the balls on which represent units, tens, hundreds, etc., and is used by sliding the balls on the wire, to tabulate the result of each successive increment or decrement of numbers. If the balls were numbered and several series were strung upon a ring, they might be passed con- tinuously in the same direction, as the addition re- quired. The Arabs, to whom we are indebted for the in- troduction of the Indian numerals, termed their treatises "Sy.stems of Indian Arithmetic." The word cipher is the Arabic tsnphora, — ' ' blank " or "void " ; alluding to its integral value. The word algebra is also Arabic. The words chemise, cotton, are also Arabic, and to the Arabs Europe is also in- debted for the introduction of the gamient and the material. Mohammed Ben Musa wrote a treatise on algebra in the latter part of the ninth century. The Khalif Al-Maimon measured a degree of lati- tude on the Red Sea shore. This, when the teach- ings of Constantinople and Rome were on the scale and stanilard of Byron's Grand Seignoir, — " He knew, because he saw, the moon was round. Also was certain that the earth was square." — Don Juan. An arithmometer was suggested by the JIarquis of Worcester in his " Century of Inventions," but was not described. It wa.s adapted for addition and subtraction. Sir Samuel Morland, in 1672-73, published a ti'eatise on the use of two arithmetical instru- ments adapted for addition and subtraction. In Fig. 325, instead of balls on a wire, a series of sectional belts operate numbered wheels, which are rotatable in one direction only. The numbers on the peripheries of the wheels are exposed at a row of openings in the case. The sections of the belt are perforated so as to be moved by a peg, the selection of the place for the peg being assisted by a row of numbere over each belt. Fig. 325. o o o o Thnus. B o o 9 s : >i h 4 :: a 1 I o| ojo : : : : oldolo a ? T ri r. 4 .f 2 1 I O i0]0| 0| O ] 0| 0| [0; 0| O 9876543 2 1 ( o|o|olo|o|o|o|o|olo!o 9fi7654;i21 r o(o|o|o|o|otojoJDJo|o y 8 7 fi 5 4 3 1' 1 1 JA. Computing Machine. The Calculator (Fig. 3261 has disks numbered on their peripheries and an'anged on a common axis. Fig. 326. 'CaleukaoT. They are moved by cogs exposed conveniently to be operated by the finger, and are so connected that Ar':tli}iiomftfr. ARITHMOMETEE. 144 ARM, AKTIFICIAL. Fig. 328. the motion often cog.s on the disk of units gives tlie next ili.sk a sin- gle impulse and registers ten, and soon through the series. The re- sult is visible at a slit in the ease. Fig. 327 has also the num- bered disks, which are moved by handles sweeping in cir- cular arcs. It performs the op- erations of addi- tion, subtrac- tion, multiplica- tion, and divis- ion, the results appearing at dif- ferent slits in the case. Space will not permit an exact elucidation of the mode of operation of tliis ingenious machine. Another form of arithmometer is that in which disks of varying diameters overlie each other, anil communicate motion to each other in regular series, as in Fig. 328, the units to the tens, these to the hundreds, etc. The principle is substantially the same as those previously described, hut the device has a compact appearance, and the result is read on a dial. One other form is analogous to the disks of a gas- meter register, which is in fact an arithmometer. Pig. 329. Disk Arithmometer. Ciphering Machine. See Fig. 329. The different disks are arranged on their separate axes, an ; the backwaril motion of the latter ex tending the joints of the prosthetic arm and hand, and the forward motion of the stump flexing the said joints. These motions are derived from bars or ARM, ARTIFICIAL. 145 ARM, ARTIFICIAL. cords whicli connect the forearm to a shield on the shoulder, as in Ivoeller's, or to bauds on tlie body, as in Condell's and in Uren's. In these cases the upper arm consists of a socket to i-eceive the stump of the limb, and is secured by straps to the person ivitli a certain degree of rigidity. The anteiior and posterior tendons or rods have a tinii attachment at or near the slioulder, pass along or through the upper section, and are attached to such points on the forearm that, as one or the other is tightened, the forearm is Hexed or extended. In some cases the oscillation or the elbow-articulation is obtained by cords which have diiector intermediate attachment to the forearm, as in Condell's and Peter- sou's ; in others the cords or bars move a toothed wheel which engages a ])inion on the elbow axis and gives motion to the forearm, as in one of Koel- ler's. The backward motion of the stump, it will be apparent, tends to strain tlie anterior tendon, whicli is so connected to tlie forearm behind the elbow- joint as to extend the foreann. The forward motion of tlie stump strains the posterior tendon which connects to the forearm in front of the articulation, and thus Hexes it as the stump is moved forward. Thesemotions follow the natural ones, as, forinstance, in the act of raising the hand to the mouth it is usual to oscillate the arm forward on the shoulder as a pivot, and backwardly as the hand descends. In the natural arm the pivotal position of the forearm is varied so as to cause the said arm to swing in an arc which will bring the hand to the required place, say the iijouth, for instance ; in the artilicial arm, the motion on the shoulder is the generator of the motion on the elbow, and a certain amount of practice and adjustment is required to proportion the parts so that the consentaneous action of the parts which produce the compound motion may, without apparent constraint or indecision, land the hand at the ol>ject. When the trunk of a per.son affords points of attachment for the Hexor and ex- tensor stra]>s, the motions of the shoulder itself, relatively to the thorax, and involving the clavicle and scajiula, may be made to assist in executing the motions required. The primary motion of the stump having been communicated to the forearm by the means described, (and the special devices are various and very inge- nious, ) the motions of the hand are derived from that of the forearm by means of tendons, slides, or other attachments. The construction will farther appear when considering some of the varieties of artificial arms, though it will not be possible to afford space for an exhaustive description even of the sixteen patents which have been selected and are now betbre the writer. One class of arms does not receive motion from the stump, but retains the position at whicli it is set by the other hand, or assumes and retains it by swinging it in one direction or the other till it is engaged by a spring latch. Drake's, also Lindsay and Vance's, are illustrations of the former; Lincoln's of the latter. To secure the requisite lightness and afford room for the operative devices, artificial arms are made hollow. The material is various, and some patents have been issued for the use of specific materials, such as rawhide, which has a toughness and strenrth. hardly to be excelled. Vulcanite, papier-mache, layers of fabric alternating with glue, veneers, card- board, and hollow wooden blocks shaped to the natural contour, have all been advocated and used. The tubular form does not always extend to the metacarpus, and the fingers especially are frequently made of solid jointed blocks, with tendon.s, cartilage, and ligaments. These prosthetic parts perform the functions of their correlatives, as being the means of motion, giving resiliency to the contact of the parts, and specific connection to the phalanges. In the latter case, the hingeing of the parts, it must be ad- mitted that the liuniau mechanic has assumed a hard task in attempting to copy the natural articu- lations, and that he has done commendably with the materials at hand. In Coxdell's arm the loop appendage is a yoke of webbing for the attachment of the socket to the stump, and for securing such a rigid connection to the body that the three straps proceeding down the humerus may be utilized when the stump is moved backward, forward, or rotated, in producing extension Fig. 330. 10 CttnJtWi Anificiat Arm. ARM, ARTIFICIAL. 146 ARM, ARTIFICIAL. anil fli'xion of the arm and tlie forward motion of tlie nietai.'ar]ius wliieli opens the phalanges. Tlie axis moves with the forearm, and a stud F thereon atibrUs a point of attachment lor the spring N, wlio.se dnty is to assist in extension. The straps D' If- are re.sjiec- tively attaehed to the yoke in prjsterior and anterior positions, and to the arm of the rock-shaft L at F anil M respectively. The draft on D' acts to Hex, and on /)- to extend, the foreann, by means of the link 1>, which is pivoted to the forearm anteriorly. Tlie flexor and extensor motions described apply to the forearm, Init do not involve the action of the hand, the metaeai-pus of which is hinged by a through pin to the mid-wrist. A post g is perma- nently attacheil in the hollow of the arm, and a spring tendon Z passes from it to a point on the metacarpus back of its wrist articulation, so as to oscillate it backwardly. This spring being constant, the normal position of the metacarpus is rearward and the lingers and thumb closed. Tlie relation of the motion of these to that of the metacarpus will be presently described. The forward motion of the hand anil the opening of the gras|i are effected by a slight rotation of the shoulder, which draws upon the strap c, oscillates the post rf, and by means of the tendon e draws forward the metacarpus extending the pha- langes. The forward portion of the forearm is sleeved upon the butt or wooden part in wliicli the post -pt (lat. 24°10'N.)wasinlhetropie, a vertical gnomon casting no .shadow at noon on the day of the summer solstice, and thence determined its" latitude to be equal to the obli.puty of tlie eclip- tic. Observations at Alexandria determined the zenith of that place to be distant -^^ ]iart of the circumference of the earth from Syeiie, the are of the meridian between the two jdaces being equal to 7° 12', whicli was measured by the Ptolemies and found to be 500 stadia. This gives roughly 250,000 ■stadia for the circumference of the earth. The Olympic stadium was 202j yards. See Odum- ETF.n. Ar'mil-la-ry Sphere. An instrument to illus- trate the motions of the heavenly bodies. It was in- vented bv Eratosthenes about B. ('. 255, and was employed'till the time of Tycho Brahe, A. D. 1582. It was ordinarily made of brass, and disposed in such a manner that the greater and lesser circles of the sphere are seen in tluir nntural position and motion. It was ]icrhaps the principal agent in astronomical observations in the museum of Alexandria, which was founded by Ptolemy Soter, B. C. 208, and was plundered by Cyril A. D. 415, who probably thought the sphere was some heathenish machine for invok- ing the infernal gods. It was used by Aristarclius, who first took the heliocentric view of the solar sy.stem ; by Archime- AKJIILLARY SPHEKE. 149 ARMOR, PERSONAL. (Ic3, tlie grand inastrr of mechanics, contcmiiora- '.icously with tlie building of tlie great wall of China ; liy Eratosthenes, the originator of astronomi- cal geography ; by Hipjiarchus, the father of mathe- matical astronomy; and by Ptolemy, the astronomer, A. D. 150, whose system was accepted down to the time of Tyclio Brahe, A. D. 15S2, and until Coper- nicus, Kepler, and Galileo revived the true views of Aristarchus, the heliocentric theory promulgated nearly two thousand yeai-s before. Fig. 336. Armiltarij Sphere E. a. b. c. d. The earth. Hour circle. North pole of the heavens. Arctic circle. Tropic of Cancer. e. Celestial hoiizon. /. Celestial equator. g. Ecliptic. A. Tropic of Capricorn. i. Antarctic circle. k. South pole of the heavens. 1. Solstitial colure (summer). m. Solstitial colure (winter). The armillary sphere consists of a frame with -a horizon on which are represented the 360°, the re- gion of the heavens, the calendar, and the hight of the sun for every day in the year. Two notches in the homontal circle, and corresponding to its uorth and south points, receive the fixed meridian, whose plane is perpendicular to. and center coincident with, that of the horizontal circle. Within this me- ridian the other circles, as well as the small terres- trial globe, may all be rotated together on the com- mon axis of tlie heavens ami eartli. The meridian can be moved in its notches, still retaining its verti- cal plane, and in this numner the general axis may be placed at various angular distances with the ho- rizon. The center of the small terrestrial globe is coincident with that of the general armillary sphere. The hour circle is fastened to the uorth pole of the tixed meridian, and has a movable index, which w hen fastened levolves with the axis. It is still used in demonstrating astronomical problems. The armillary spliere of the Hindu astronomers is described in the Sanscrit treatise *' Siirya-sidd- hiiiita," translated by Kev. E. Burgess, and jnib- libhedin the Journal of the American Oriental Society, Vol. VI. pp. 141 -49S, New Haven, 1S60. The in- strument was illustrative of the positions and motions of the heavenly bodies, rather than for astrononiiial observations; in this respect diflering from the Gre>-k, Arab, and early Europeau instruments. Arming, {\aiilkal.) A plug of tallow in the hollow at the bottom of a sounding lead, to bring up sand, minute shells, infusoriae, etc., from the bot- tom. Arm'ing-press. {Boo/Mnding.) A screw press having a [ilatiii heated by gas-jets, and serving to fix the gold-leaf upon the book-covers upon which it is impres.sed. See BLuCKiNG-riiEss. Armlet. A clasp or loop for confining the sleeve to the u)iper portion of the arm. Used to loop up the short sleeve of children's dresses. A protecting sleeve of leather or metal, worn on the forearm, and used as a shield for the arm or as a covering for that portion of the coat-.sleeve. Ar'mo-rer's Gage. For verifying the dimen- sions of the various [larts of small-arms are templets of various sizes and shapes, rings, and cylindrical or conical gages for interior dimensions. 200 are embraced in a complete set for the various amis made at the GoveiTimeiit armory, of which about 78 are used for the riHe-musket alone. Of these, the culibcr gatjc measures the diameter of the bore. The dimcnxion gages show the length of the barrel and its diameter at various distances, the value in inches and parts being measured by the caliper galates, in which the lower ones over lap the higher, so that when any one of them is struck by a projectile, the projecting edge may become detached, glancing the shot on to the ne.\t plate, by which it is further deflected and prevented from penetrating the armor. __ The cut represents the action of a cy- lindrical bolt whose edge has impinged upon one of the lapping plates ; the dotted lines show the bolt in a subse- quent position, in contact with the piece of armor-plate which it has re- moved, and glancing upon the succes- sive plates. AVoou's armor, September 23, 1862, comprises sets of inner and outer plates, the fomier secured to the vessel by bolts whose heads are covered by the latter, each plate in the one set having a rib which fits between ribs on a plate of the other set, the two plates TTood's Armor, being connected together by pins jiass- ing vertically through the ribs. Lon- gitudinal spaces are left at intervals between the inner and outer jilates for the introduction of wood or an equivalent material. Barbitt's armor-plating, January 13, 1863, for ships or batteries, is composed of wedge-shaped bars laid crosswise to two other sets of bars, the whole be- ing dovetailed together and filled in with cast metal. Montgomery's armor, February 10, 1863, de- pends much upon its resiliency to resist the im- pact of projectiles. The outer plates are notched into each other, and fastened together and to a corrugated plate by a rod. This corrugated plate rests against the outer casing, between which Fig. 348. Pi n M r-1 M 4Jl and the inner casing are cyl- inders of vul- canized rubber placed perpen- dicularly to the casings, the whole being bolt- ed together. BuAOY'smeth- od of " Attixing defensive Armor- Plates," Jlarch 3, 1863, is by at- taching them edgewise to the object to be pro- tected, and se- curing them by means of bolts, whose ends pass into cavities in the inner edges of the plates, and are made fast by being enlarged therein, or by being intersected by transverse apertures through which jiins or keys may be passed. In Wap- PICH's sys- Fig. 349. tern, Jlarch 3, 1863, the outer Jilates have jirojec- tions ])assing through the hull and in- terior plat- ing, where the y a r e keyed ; each outer plate has ako projections or lugs Jc, enterint; the casing rf to a certain distance, and receiving U U U Sabbill's Armor-Plating. Montgomery's Armor. Fig. 350 Fig. 351. Brariy's Armor-Plating. the bolts I, which are keyed to the interior plate : it has also notched flanges, or bent ends, ]iass- ing into the casing ; these are employed to bind the ends of the plates to- gether, and increase the stability of the armor. The outer adjoining edges of the plates are grooved for the insertion of india- rubber strips, as at m, for making the joints water- tight. The port-holes are strengthened by iron W "B v^ o r Wappich'^s Armor. ARMOR-PLATING. 154 ARMOR-PLATING. Fig, 352. plates 0, extemliiif; ai-ouiid their eilges, and also by an ■.■lU'irulin;,' IVaiiic or riiif; r, bi'twccn tlie iiiiicr and out- er plating. Eaeli plate.niay be so arranged as to lie jmslied out, upon removing tlie keys A, and otlu'rs snb.stitnted. This system of plating is designed lor cireular turrets, .as well as I'or plain or slightly curved surfaces. TuFTs's Construction and Uefence of War Vessels, March 24, ISliS. The sides of the vessel are recesseil by bending inward the frame and the plating thereon, thus maintaining the sym- metry of the outward form. Recesses are made in the sides, in wliich the fixtures in m arc secured, having eyes into which screw-bolts / / are hooked. These screw-bolts pass through the easing to the outside ol' the straps ;/, where they screw into nuts. Eaiis's Defensive Armor for Marine and other Bat- teries, July 14, 1863, eon- Titjis's Armor. sists oi' inner angle-irons, tlie Hanges of which [lass between tlie liorizontal layers of armor-plates. Dow- el-pins, inserted in holes in the Hanges, enter the Fig. 353. ^ ^Z T Fig. 3.54. Fi-. 355. ■ .n.,rl Ett3 Defence 3,72J [Re.^istince '3,710 iCdleJonia lOccan jPrince Consort Roval .\lfrea Iloyal Oak Lord Clyde Lord Warden Zealous •Bellcrophon iPallas I ■Favorite 'Re.574,001 280 59 3 716' 800 252 59 4.2461,000-300 56 ,2,372 2,094 1,253 9*3 73: 754 2, .529 Iloyal Sovereign 3,765 Scorpion ,Wivem 1,85; 1,851 600225 50 4)K)225 47 200195 38 160 190 3^ 1 im Zl 160 W> 32 167 162 Zi 500240 48 800 240 62 3.50 220 42 350 220 42 3<£ ■s Sti = 2 1 II ■|< H 26 4i 21 a 26 44 31 H 36 5J 36 5,1 3'! 41 .32 4i 16 4i 16 44 32 44 ' 3^, « 1 .3^ 41 ;fi 4V,6 1 32 41 .34 41, 5',, 6 34 41,31,6 16 '41 12 6 5 *i 8 4V 1 4 44 4 4 2 41 2 41 6 44 6 41 5 51 4 3,41 4 3,41 Thickness of Backing. 18 18 18 10 10 10 18 18 18 18 Wood ship, side 294 in- ■• 29V " " 294 " " 294 " " 234 " " 3U " " 311 •' " 304 " 10 ( Wood ship, (side 22 in. " 26 •' " 19 " " 194 " 10 10 10 13 ( Wood ship, I side 3) in. 9 9 "The British naval authorities have lately tiled a practical, if expensive, experiment by anchoiiug their biggest and newest iron-clad, the " Glatton," in Portland harbor, and detailing another ship to make her turret a target for 600-|iound jirojectiles. The Admiralty is probably satisfied with the trial, for although the turret was pretty badly damaged it was not dis.abled. The experiments will be contin- ued in the hope of finding a system of iron-platiug which will resist any possible projectile, and a pro- jectile which will knock to pieces any possible sys- tem of iron-plating. " — English Paper. This is of a piive with tlie old problem, whi.h modern slang would call a conundrum : " When an irresistible body comes in contact with an immova- ble object, what is the result ?" Ar'mor, Sub-ma-rine'. Submarine armor may be held to include all the devices to be attached to the person by which one is enabled to descend in the water, be pj'otected from exti'cme pressure while sub- merged, be furnished with vital air and with means for signaling the persons above and for assisting the ascent to the surface when necessary. These devices have been used in connection with the diving-bells, but the latter is not a necessary auxiliary. In tlie article on the diving-bell some instances of subma- rine amior are given, but only as incidentals. Sulnnarine armor has not as clear claims to antifj- uity as the diving-bell, if wc accept the accounts of Aristotle and Jerome. The earliest distinct account of the diving-bell in Europe is ]irobably that of -Tohn Taisnier, (juoted in Schott's Tcchnka Curiosa, Nuremberg, Ititil, and giving a history of the descent of two Greeks in a diving-bell, " in a very large ket- tle, suspended by rope, mouth downward " ; which was in 1538, at Toledo, in Spain, and in the pres- ence of the Emjieror Charles V. Beck man cites a print in editions of Vegetius on War, dated in 1511 and 1532, in which the diver is re])resented ill a cap, from which rises a long leather pipe, terminating in an opening wliich Hoats above the surface of the water. • Dr. Halley. about 171", made a number of im- provements in the diving-bell, and among them a leather cap for the head of the diver, with windows in front for the eyes. This helmet was used by the diver when he left the bell, from which he received a supply of air through a flexible tube. The essential parts of submarine armor consist of a helmet and a protection for the body. These are rendered necessary by the great ju'cssure of the wa- ter even at moderate depths. For instance, at a depth little exceeding five fathoms (30 feet), this jiiessure amounts, including that of the superincum- lient atmosphere, to about 29 pounds to the sipiare inch, being an excess of some 14.7 pounds over that due to the atmosphere alone. For dej>ths not ex- ceeding 15 or 20 feet, amior for the body is not ])erhaps absolutely essential, though very desimble if the diver is required to remain a considerable lime under water ; this part of the apparatus may be constructed of leather, vulcanized rubber, or giitta ])ercha, or of metal. The helmet is almost necessa- rily made of metal. It has glass windows to enable the diver to see, and two tubes. — one for supplying him with fresh atmospheric air from the surface, and the other for the eduction of the exhaled air. Weights are attached to the body of the diver or to the armor, if the hitter is not sufficiently heavy of itself, to enable him to exert liis full power under water ; the human body being very nearly of the same specific gravitv as that fluid. A line is at- tached to the "apparatus, by which the operator is lowered to any given depth, or hauled to the surface by the assistants, and by which he can signal to tl'ieni when necessary ; for this purpose, however, an- other line is usually employed. Many diflerent con- structions have been proposed and executed. One of the best of the earlier forms was that of M. Klin- crert of Breslau, 179S, in which the helmet was made of strong tin, and the jacket and dmweis of leather. Inhalation was made through a tube embraced by the lips of the diver, who, by the expansion of his chest at each inspiration, forced out of the helmet into another tube leading to »lie surface a (piantity of preriously exhaled air precisely equal to the fresh ARMOR, SUBMARINE. 156 ARMOR, SUBMARINE. ail' taken into tlie lungs. In some of the older furnis the helnu't itself was made large enough to hold a quantity of air sutlirient to supply the diver for ii consideralile length of time, dilfering little, in faet, from the diving-bell. The a|iparatus of Jlr. Howe, 1753, consisted essentially of a eopper tulie huge enough to eontaiii the Fig. 359. body of the diver and a limited supply of air whieh could be renewed from time to time by a bellows or force-pum(i, and having windows and wa- ter-tight holes lor the arms. These eases have, however, been completely .su]ierseiled by the diving- bell, and it tiy the more Unodern forms of armor, ^some of whieh will be mentioned. .See UlvlN'G. Fig. 359 shows a figure in a diving-dress, attached to which is a reservoir of eominessed air sufficient to last the diver .several liours. It is strapped to the dress, and communi- cates with the intei'ior of the latter by a pipe which has a faucet. Expansi- ble bags are attached to the shoulders, which are nnule buoyant by inflation from the compressed-air reservoir when re(iuired. The air-knapsack is weighted so as to enable the diver to sink to his work. T!ie air-tube enters the mask at a point over the ear. The artist has made i-ather a dose ht of the dress ami mask, and the ell'ect is ratlier too cherubic. In Fig. 'Mil is shown a rcs]iirator designed to be Dii'ing A/'paratus. Ilnivfcim'; Mniilhjiiire for Difin^ Aji/'tirlitits attached to the ^ ^ Fig. 360. helmet of the diver whereby air is supplied from a force- Iiuni]) in the ves- sel which tloats on the surface of the water. 1 1 has an induction and an eduction valve, which both open iu the same direction, giving way respectively to the blast of fresh air and to the force of the exhaled biealh. While the breath is being inspired by tlie diver tlie iiiduelion-valve is o]ien to admit fresh air, and when expiration occur.s, the induction-valve is clo.sed, and the air passes out by the eduction-valve and the I.e.xible tube, which latter reaches to the surface of the water. In Fig. 361 the diver is completely incased in the armor, whieh has flexible jointed linil}s occnjiied liy the legs and armsol" the occupant, and enabling him to move from place to place and grasp the objects of his search or iierform his other duty in the (iremises. The joints of the limb-casings have articulations corresponding to tho.se of the jierson, and are tie.xed and extende of the apparatus. As the hag becomes inflated, it dis- places water and renders the whole apparatus buoy- ant. To descend again, he closes tlie cock leading to the balloon, and opens another which allows the air to escape from the balloon, which is collapsed by the pressure of the water. The compiesscd air is intended to form a supply foi- the trip, tlie connec- tion with the surface consisting of a lifting and lowering rope and the eduction air-pipe. Other armor for submarine explorations consists merely of helmets which have the necessary win- dows to allow the diver to see his work, and aie pro- vided with induction and eduction tubes to furnisli the operator with a supply of vital air and carry oli' that which is vitiated. Some exploring apparatus are adapted for making observations without descending. These consist of tubes, telescopic or otherwise, the lower end being brought into near proximity to the object ; and in one case — Knight's Eugli.sh Patent, about 1847 — a second tube was provided, down wliich was projecteil light from a lamp or the reflected light of the .sun, so as to illuminate the object whose character or position it was desired to a.scertain. In 1839, Thornthwaite (England) adopted a waist-belt of india-rubber cloth, to which was cy his boat with its usual air-pump rigging. The time made was 17, 18^, and 21 minutes respectively. Each received a prize. Ar-mo-zine'. {Fubric.) A thin plain silk, gen- erally black, and used for clerical robes. Arms. The club was the first offensive weajion. By knots and points it became a mace ; an edge and a pole converted it to a battle-axe. It was adapted for thrusting by giving it a point, and became a pike or spear ; and when adapted to be thrown be- came a dart or javelin, which might be recovered by a line, as among the JIooi-s. .Shortened and ]iointcd, it became a dagger or poniard, and by receiving an "dge became a sword, scimeter, or .similar weapon. Pointed, and associated with a motor to propel it, we see the arrow and its bow, which is, critically con- sidered, a really beautiful invention. See .AlicHEI'.Y. ** The fii'st weapons of mankind were the hands, nails, and teeth ; also stones and branches of trees, . the fragments of the woods ; then Hame and fire ; were used, as soon as they were known : ami last- I ly was discovered the strength of iron and biass. ' But the use of brass was known earlier than that of ] iion. inasmuch as its substance is more ea.'y towoi-k, and its abundance greater." — Lvcektius; d. 51li. c. at. 44. History commences after the invention of the how and arrow, and the Australian race seems to have diverged from the parent stock before its intiodnc- tion, as they, and they only, do not possess it. Thev have a curious analogue, however, in their flexible spears, which are bent, whi-n adjusted for throwing, so that their reaction in straightening may increa.se the force of the projection. The ]iecu- liar course of their flight when they diil not straight- en perfectly may have suggested to them the very uniiiue weapon, the boomerang, which was imported into England as a curiosity perhaps 30 years ago. During the historic period we find the most an- cient weapon noted in the Bible is the sword. It was the " instrument of violence," as Jacob called it, wheiewith Simeon and Levi slaughtered the Sheche- niites (Genesis xxxiv. 25). I'hineas, the giandson of Aaron, carried a javelin. Ehud had a short dagger (Judges iii. 10). David de- clined Saul's sword, and used a sling, but afterward took the sword of Goliath. JIany centuries before, all these weapons had been used in China, India, A.'syiia, and Eg>pt. Pliny ascribes the invention of the sling to the PhaMiicians. The Ba'earic Islanders were celeluated for their expertness in its use. Slings and bows were employed by all the nations of antiquity, but among those who attained the highest miiitary reputation, as the Greeks and Ro- mans, were looked upon merely as anxilinry wea])- ons, and the soldiers who used them were considered as an inferior class. The heavy-armed .'oldiers, who composed the strength of their armies, were armed with the spear and sword. The foimer, as used by the Greeks, was some 16 or even IS feet in length, and enabled them to form a line of battle llj men deep, — a solid mass capable of with.staniHng the most vio- lent shocks, or of breaking the firmest ranks of any enemy who was not armed and di^^ciplineil like themselves ; it was, however, deficient in mobilityand activity. The Romans, on the contrary, pieferred an order of formation and weapons which admitted of greater activity and allowed more scope to the etfoits of the individual solilier. Besides a lighter tpear, their principal weapon was the pihim, a short and massive javelin with a triangular iron head, which was darted by hand when within a few paces of their opponents, after which they drew their swords and advanced lor close conflict. The Roman foot- soldier's Sttord was a short, two-edged weajion, greatly resembling the foot-artillery sword formerly used in the United States Army, and was adairted for either cutting or thrusting, though the soldier was instructed to prefer the latter as more ellective and permitting him to preserve a better guard of his own pei'son. The foi-mation of the legion was in eight ranks, and a distance of three feet was preserved between each file, as well as each rank, thus allowing ample room for the maximum effort of each separate man. The offensive arms of the cavalry were a javelin and a long broadsword. Cavalry does not seem to have performed such an imiiortan't part among the Greeks and Romans as it did among the more Eastern nations, as the Parthi- ans, whose mounted archers, on more than one occa- sion, defeated and almost annihilated the legions of Rome. Noimportant change in amis, except the introduc- tion of the cross-bow, seems to have been made until the introduction of gunpowder ; though the charac- ARM-SAW. 158 ARXOTT'S STOVE. ter of the forces emjiloyi'd underwent a coniidete revolution. As Eurojie settled down into the gloom of the Midille Ages, diseiplineil iinuies beeuiiie iin- knowji, and the barbarous nations of the North who had overrun it, in the eourse of time beeoniing convei'ted into peaceful tillers of the soil, had lost their former military habits, and in times of war degenerated in to little betterthan eanii) followers. Cavalry, iuehuliug the knights and men-at- arms by whom they were attended, eonstituted almost the entire strength of an army, and being nearly invulnerable to tlie ordinary wea|ions used by the tbotmeu of that day, sueh as pikes and bills, were capable of putting to llight or slaughtering with impunity many times their own number of the latter, who were in general destitute of armor of any kind. The ijitroduc- tion of fire-arms has gradually effected an en- tire change in the composition and discipline of modern armies, ami though the lance and sword or saber are still employed, they are used merely as auxiliaries. See Ain'iLi.Eiiy, FiitE- Alt.MS, PuoJEcTiLEs, etc. For a list of arms of various kinds, cutting, missile, etc., see We.II'OXS. " Ships' anns are cannons, carronade, mortars, howitzers, muskets, pistols, tomahawks, cut- lasses, bayonets, and boarding-pikes." — Ad.mi- r.AI, SMYtll. Arm'-saw. Another name for the hand-saw. Arm'strong Gun. A desciiption of ord- nance adojited in the English artillery for all lield-guns and many of larger caliber. It is built up of ditt'erent parts, so disjiosed as to bring the metal into the most favorable position for the strain to which it is to be exposed. See Can- non. Fig. 362. and tightening the gas-check b in its seat, to pre- vent any escape of gas rearwardly. Ai'mure. {Fabn'c.) A lady's dress-goods, hav- ing a coitnn cliaia and woolen Idling, twilled. Ar'my Wae'cn. A w agon designed for the use of foot-soldiers on the plains, and so constructed Tig. 303. Armstrong Gun. The illustration does not show the mode of huild- inrj up the gun, but illustrates the mode of breech- loading. Tlie inner portion of the barrel is made of coiled iron or steel, weldelied to wagons for stores and ammunition. Ar'nott's Stove. The original form of Dr. Ar- nott's stove is shown in Fig. 3li4, and perhajis illus- trates its ])eculiar principle better than do the subsequent modifications. a b d represent a box of sheet-iron, divided by the partition 3 h into two chambers, communicating freely at the top and bottom ; e is Fig. 364. the fire-box, formed of iron, lined with fire- brick and resting on a close asli-jjit with a door at b, near which is a valved opening ^ by which air en-' ^ ters to feed the fire when the door is shut ; lis the door of the stove by which fuel is in- troduced ; c is the c h i m n e y - 11 u e . When the ash-pit door and the stove-door are shut, the quantity of air admitted by the valved open- ing in the ash-pit is only just sufficient to support combustion, and only a small corresponding quantity of air can pass away by the chimney. The whole box then soon becomes filled with hot air, or smoke from the fire circulating in it, and rendering it The Arnott Stove. everywhere of as uniform temperature as if it were block into the conical seat at the rear of the bore, I full of hot water. This circulation takes place. ARQUEBUS. 159 ARRASTRA. because the air in the front chamber around the fire-box, and wliich receives as a mixture the hot air issuing dirccth' from the fire, is hotter, and there- fore sjiecifieally lighter, than tlie air in tlie posterior chamber, which receives no direct heat, but is always losing heat from its sides and back ; and thus, as long as the lire is burning, there must be circulation. The whole mass of air revolves, as marked by the arrows, with great rajiiclity. The quantity of new air rising from within the fuel, and the like quantity escaping by the flue c, are very small, compared with the revolving mass. Tlie methods of regulating the supply of air will be noticed presently. With this stove, Dr. Arnott, during the severe win- ter of 1836 - 37, w-as able to maintain in his library a uniform tempcra- i'ig- 365. ture of from eO°to jl jj ^.^^^ 63°. The quan- tity of coal used (Welsh stone- coal) was, for sev- eral of the colder months, 6 lbs. a day, — less than two cents' worth, — a smaller ex- pense than that of the wood used in lighting an ordi- iiaiy lire. The grate or fire-box, fully charged, held a supply for twenty-six hours. Another com- mon form of this stove is shown in Fig. 365. A B C D is tlie outer casing ; E the fire-box over which is a dome /.•, with a funnel p, to carry ott' the products of combus- tion ; h is the stove-door, and (j the regulator by which air is admitted. The device for automati- cally regulating the supply of air is described under Thf.rmo.st.\t (which see). Ar'que-buse. This piece, an early attempt at a portable fire-arm, had a massive stock laid to the Fig. 366. The Arnott Stove. Arquebuse. shoulder, and an offset near the muzzle by which it might be rested against an object, to break the recoil. It was fired by a match. It was used in the battle of Morat, where the Swiss defeated Charles the Bold, 1476. Ar-ras'tra. One form of machine for commi- nuting ore. The name is derived from the Spanish word meaning "to drag," and is indicative of the machine. It consists of a pan in which the ore is placed, and a vertical rotating post, to whose radial arms are attached thongs by which blocks or mullers are dragged over the ore in the pan. They are very common in Mexico, where they operate upon argentiferous ores, and, according to Humboldt, do excellent work. They have been superseded to some extent b)' other forms of grinding-mills. See Am.\i.gamatixg Mills ; Ore-st.\.mp ; Ohk-ciu^shek. Three arrastras ^ire patented in the United States. Fig. 35' Fig. 367 lias the distinct arrastra characteristics, and is designed for the reduction of precious metals from ores and tailings : it ha-s a cast-iron iian provided with two flanges, placed on o]iposite sides, ami termi- nating in a ball-jiivot, which rests in a cup-shaped liearing on the frame, by which means the arrastra can easily be tipped when the contents are to be drawn off. A cup-shaped cavity serves also as a bearing for a ball-pivot at the lower end of the hollow shaft. In another form the circumferential band on the inside surface of the arrastra is connected with the Fig. 368. Arrastra. positive pole of the battery, and the metallic radial gutters are attached to the encircling wire connected to the negative pole. The arrastras being filled with the pulverized ore, water, ami mercury, the electric current is causeil to pass through the mass, and is intended to facilitate the separation of the metals from their chemical combinations, and further their amalgamation with the mercuiy. Fig. 369 is designed as an improvement on the Bertola ilill, October 20, 1857, but difl'ers from it in the fact that the mullers /are linked to the arms ARRASTRA. 160 ARROW. Bertola^s Arrastra. Bertola's Mill, 1857. rig 369. /,■ of tlic rotating- shaft, so that rach is IVci! to accommo- date itself to the material overwhicli it is dragged. The basin in whiau, and formed of an annular disk from whose opposite edges a portion was removed, leaving concave sides. The liottom of the muUer was grooved, and the part removed left spaces for the ore on each side, between it and the basin. It was i-evolved by a shaft above, lowered into op- erative contact with it as rerjuired, and the pulp was discharged liy openings near the bot- tom, which were un- stopped when the pan was tilted on a hori- zontal axis. Openings above and at the bot- tom, respectively, dis- charge the water and the amalgam pu'p. The arrastra, as usually constructed, ami described by Phillips, consists of a circular pavement of stone, about twelve feet in diameter, on which the quartz is ground by means of two or more large stones or mullers dragged continually over its surface, either by horses or mules, but more frequently by the latter. The periphery of the circular jiavenient is surrounded by a rough curbing of wooil or flat stones, forming a kind of tub about two feet in depth, and in its center is a stout wooden post, firmly bedded in the ground, and standing nearly level witli the exterior curbing. Working on an iron pivot in this central post is a strong, upright wooden shaft, secured at its upper extremity to a horizontal beam by another journal, which is often merely a prolongation of theshaft itself. This upright shaft is crossed at I'ight angles by two strong pieces of wood, forming four arms, of whiidi one is made sufiieiently long to ailmit of attaching two mules for working the machine. The grinding is performed by four large blocks of hard stone, usually porphyry or granite, attached to the arms either by chains or thongs of rawhide, in such a way that their edges, in the direction of their mo- tion, are raised about an inch from the stone pave- ment, while thi^ other side trails upon it. These stones each weigh from three to four hundred pounds, and in some arrastras two only are em- ployed, in which case a single mule is sufficient to work the machine. Fig. 371 is a sectional view of a Mexican airastra as usually constructed ; A is the upright shaft ; B, the arms, to which the nnillers C are attached ; and D, the central block of wood in which the lower bearing works. Some of tlic arrastras u.sed by Mexican gold- miners, for the ]iuri)Ose of testing the value of quartz veins, are very rudely put together, the bot- tom being made of unhewn tlat stones laid down in Fig. 371. Mfxican Arrastra. clay ; but in a well-constructed arrastra, intended to be permanently employed, the stones are ( arelully dressed and closely jointed, ami after being placed in their resjiective positions, are grouted-iu with hydiaulir ci'inent. Ar-rest'er, Li^ht'ning. x\n instrument used on telegrapli-lines, by which static electricity of high tension (lightning) is discharged from the line to the cartli, to prevent injury to the telegraph instru- ments or the operators. It consists of an inteiTiosed resisting medium which is traversed by a current of high tension, aiul allows the charge to pass to the earth, but which opposes the passage of the ordinary voltaic current. See Lioht.ning Auukstkr. Ar'ris. The external angle or edge formed by the meeting of two plane or curved surfaces, whether walls, or the sides of a stick or stone. Ar'ris-fil'let. A triangular piece of wood placed under a lower course of slates, tiles, or shingles. Ar'ris-gut'ter. {Carpcntrj/.) A V-gutter fixed to tlii' dri[i]ang-i'aves of a building. Ar'ris-pie'ces. The portions of a built mast beneatli the hoops. Ar'Tis-Tvise. Diagonally arranged ; said of tiles or slates. Ar'row. The missile which is projected by n bow. liundles of arrows W'ere called sli£iivcs. It is usually of reed or of wood, and tipi>ed with the best accessible materials ; such as bone, flint, obsidian, metal. The old English rale was to have the arrow half the length of the bow, and the latter the length of the archer, so that a cloth-yard sluift was used by a man six feet high. The holt was a peculiar arrow adapted to be shot from a cross-bow. The arrow of an arbalest was termed a qunrrcl. Immense quantities of flint arrow-heads are found in the Celtic barrows throughout Europe. The ar- I'ow-hcads of the Scythians and Greeks were of bronze, i and had three llanges like a bayonet ; such have been found at Persepolis and Marathon. The "bar- ■ barians," say the classic writers, tise barbed {adiin- ccc, hrmata:) and poisoned {iriicnatcc) arrows. The poison on the arrow was called tnxicum, from its relation to the bow, and the word was extended to poison in general. The shaft was of polished wood, cane, or reed. The latter actually gave names to the weapon, — arnndo, calamus. The Egyptians used reed shafts ; their arrows were from 22 to 34 inches in length, and are yet extant. The monuments show feathered .shafts. In the time of Homer, arrows were sometimes poi- soned. The poi.soned arrows of the Indians of Guiana are lilown tlirough a tube. They are made of the hard wood of the OukarUo tree, are about the size of a ARROW. 161 ARSENIC FURNACE. knitting-needle nine inches long, and mounted on a yellow reed four or five feet long. One end is sharp- ened, and poisoned with woorai ; the rear end re- ceives a pledget of cotton to act as a piston in the tube. The eH'ective mnge is about forty yards. The hard- wood spike can be removed at pleasure ; twelve or fifteen such spikes are carried by the hunter in a little box, made of bamboo. The poisoned spike is cut half through, at about a quarter of an inch above the point where it fits into the socket of the aiTow ; and thus, when it has entered the animal, the weight of the shaft causes it to break off, the shaft falls to the ground uninjured, and is fitted with another poisoned spike and used again. In like manner the arrows of the Bushmen, Africa, often have the shafts partly cut through, so that they may break and leave the point in the wound. The serrated weapon of the sting ray is used by the Malays for heading some of these blow-arrows, with the e-^cpress intention that they might break off in the wound. The arrow-heads of the Shoshones of North Amer- ica, said to be poisoned, are tied on purposely with gut in such a manner as to remain when the shaft is withdrawn. A similar idea is carried out in a Venetian dagger of glass with a three-edged blade, having a tube in the center to receive poison. By a certain wrench the blade was broken off, and remained in the wound. " In passing overland from the Essequibo to the Demerara," says Waterton, " we fell in with a herd of wild hogs. An Indian let fly a poisoned arrow at one of them ; it entered the cheek-bone and broke off. The hog was found dead about 170 paces from the place where he had been shot. He afforded us an excellent and wholesome supper." The wild tribes of the Malayan peninsula, who use poisoned arrows, eat the meat of animals killed by these deadly weapons, without even troubling themselves to cut out the wounded part. There is reason for supposing that the discovery of the various poisons used for weapons, and the practice of applying them to such a purpose, arose spontaneously and separately in the various quar- ters of the globe. Poisoned weapons are useil by the Negroes, Bushmen, and Hottentots of Africa ; in the Indian Archipelago, New Hebrides, and New Caledonia. They are employed in Bootan, Assam, by the Stiens of Cambodia, and formerly by the Moors of Mogadore. The Parthians and Scythians used them in ancient times. The composition of the poison varies in different races ; the Bushmen, Hottentots, and others, using the venomous secretions of serpents and caterpillars. In the Bosjesman country. Southern Africa, the na- tives hunt the puff-adders, in order to extract the poison. They creep upon the reptile unawares, and break its back at a single blow. The poison-glands are then extracted ; the venom is very thick, like glycerine, and has a faint aciil taste. This is mixed, on a flat stone, with an acrid poisonous gum, called " parki " ; after being worked until it becomes of the consistency of thick glue, it is spread over the barbed head of the arrow and for about two inches up its point. The arrows are then dried in the sun. Each warrior carries some half-dozen of these devilish weapons, a wound from one of which is as deadly as the bite of the adder itself. In Ceylon the cobra-tel poison is extracted from certain venomous snakes, such as the Cobra de Ca- pello (from which the poison takes its name), the Carawella, and the Tic polonga ; arsenic and other 11 drugs are added, and the whole is " boiled in a hu- man skull." Three Kabra-goyas {Hydrosaurus sal- ■valor) are tied near three sides of the fire, with their heads toward it ; they are tormented with whips to make them liiss, so that the fire Uiuy blaze ! The froth from their lips is added to the boiling mixture, and as soon as an oily scum rises to the surface, the " cobra-tel " is complete. Pjobably the ai-senic is the most active ingredient in this poison. The Cells are said to prepare poison for their ar- rows in the following manner : " They first kill a cow, and take from it its liver ; they then collect rattlesnakes, scorpions, centipedes, and tarantulas, which they confine in a hole with the liver. The next process is, to beat them with sticks, in order to enrage them ; and, being thus infuriated, they fasten their fangs and exhaust their venom upon each other and upon the liver. When tlie whole mass is in a state of corruption, the women take tlieir arrows and pass their points through it ; these are then allowed to drj' in the shade." The Indians of Choco and Barbacoas use the " Veneno-derana," or frog poison, which is obtained by placing a species of yellow frog, that frequents the swamps, over hot ashes, and scraping off the viscid humor that arises. After thus tortuiing the frogs, they are allowed to escape, in order that they may sen-e another time. " Veneno-de-culebra," or snake poison, is also said to be used in Choco. {Fortification.) An advanced work at the foot of the glacis, consisting of a parapet whose faces form a salient angle. It has communication with the cov- ered waj' cut through the glacis. [Surveying. ) One of the iron- wire ])ins employed in marking the chainage. One is placed in the gi'ound at the end of eacli chain. An arrow is ten inches long, with a loop at the up]ier end, and is all the better for a red flag to ren- der it conspicuous. Called also a chain-pin. Ar'3e-nio. A soft, brittle, and poisonous metal of a steel-gray color. Equivalent, 75 ; symbol, As. ; specific gravit}', 5.7. It volatilizes, exhaling an odor of garlic ; fuses at 400° Fah., and is easily in- flamed. It combines with oxygen in two propor- tions, forming arsenious and arsenic acids. The former salt is As. 75, 0. 24 ; the latter, As. 75, 0. 40. The former is the common white arsenic of commerce, very poisonous, and a dull white ]iowder, sp. gr. 3.07. It is used to alloy lead for shot-making, causing the metal to pour more readily, and hardening the shot. Ar'se-nic Fur'nace. A furnace in which arseni- cal pyiites is decomposed by heat, producing white arsenic, which is an oxide of the metal chemically known as arsenious acid, the arsenic of commerce. Arsenic is combustible, oxidizing so rapidly as to burn with a livid flame, the fumes being condenseii in large chambers which resemble the successive stories of a house. The floors have openings, so that the fumes traverse each apartment, and the light powder is deposited. The furnace is a muffle »», with an inclined sole, and haHng a fire-chamber beneath. The sole rests upon brickwork which has numerous openings, fonning circulatoiy flues d around the muffle. The arsenical pyrites is introduced at the hopper/, and the smoke escapes by the flues 1 1. The condensing chambers have openings by which the collected arsenic on the respective floors is re- moved, the lower chamber being entered by the duct 0, which proceeds from the muffle. ARTERIAL COMPRESSOR. 162 ARTESIAN WELL. Fig. 372. 572niJ Arsenic Furnace, The Jepobit in tlie lowest cliamber is the purest. Fig 373. wjmV^ . . I Condensing Chamber. Ar-te'ri-al Com-pres'sor. {Sun/iml.) A form of toviniiciiu't invented by Signoroni, to be used in ani- )iutati"iis at the hip joint, to control the circulation at the groin without iuipeding the return by the veins. Ar'te-ry Cla'w. {Surgical.) A locking forceps for seizing an artery. Ar'tery For'ceps. An instrument for catcli- ing an artery. These for- ceps are made straight, cuiTed, plain, or rat- toothed, spring-open, spring-shut, or catch. The illustration shows three forms. Ar'te - ry-o -tome'. A post-nioi'teni or dissect- ing instrument, for slit- ting an artery. Ar-te'sian Well. Artesian wells are so called because it was generally supposed that they were first used in the province of Artois, France. They apjiear, however, to have existed in Egypt at a very remote Artery Forceps. date, and are said to be found in the province of On-Tong-Kiao, in China, of the depth of from l,500tol,800 feet. The jirinciple of their action is this: waterpercolating through ]ier- vious strata, such as sand, gravel, or chalk, is finally arrested in its downward course by an impervious stra- tum of rock or clay, causing it to accumulati' in tl>e pervious stratum above as in a resen-oir, and wlu n the source of supply is higher than the level of the ground at the placewhere the well is bored, the water will rise to the surface, or even considerably above it ; in many cases issuing from the inoutli of the well with sulii- cient force to throw a jet of the water to a great hight, or admit of its being carried high enough for distribution to the upper stories of buildings. The term " artesian " is only properly applied to wells in which the water rises to or above the surface, so that in case a large number are collected in a single neighborhood, some orallof them, jiarticularly those toward the higher jirrt of the basin, may Ijccome converted from artesian into ordinary wells. In the London basin, where a great number of artesian wells have been bored, the general level of the wa- ter has been very much diminished. It generally happens that more than one, frequent- ly many, water-liearing strata are penetrated before one is reached which has a sufficient head to cause an overflow at the surface ; in such cases others he- sides the lower one may be made available, if thought advisable. The wells of the London basin will perhaps afford as good an illu.stration of the theory and action of artesian wells as any other exam]>le ; the character and succession of the beds having been moie care- fully studied and worked out than almost any oth- ers where such wells are located. These wells derive their supply from the pervious strata of the plastic clay and chalk. The.se stiata are covered in part by the formation called the Lon- don clay, which is, in most of its beds, tough ami im- peimeable to water, so that the rain falling on those parts of the jiorous chalk and other pervious stiata below it, which are not covered by the supeijacent impervionselay, percolates through them till it.slartlu'r progress downward is stopped by the "gaull," an- other stratum of imjiervious clay, and accuiuulaies tween it and the overlying clay, which acts as a cover to this vast subterraneous leservoir to the le\i'! of the line B A. The water, reaching points, as C, at the lower levels of the junction of the chalk and clay, the pervious and the imper\'ious strata, comes to the surface in the form of springs which act as ditchaige- outlets. In this case a horizontal line, as A B, drawn througli C, indicates the general level of the water in the basin, unless disturbed by faults or shifts in the strata permitting a part to be carried off at a lower level. In the latter case, if the outlet had an area of capacity for carrying off an amount in excess of the supply received from the clouds, it would determine the water-level ; if less, the level would fluctuate somewhere between this lower point of discharge and the line A B, in projiortion to the amount of rain falling on the exposed portions of the pervious strata. If a boring be made anywhere through the over- lying clay beds, it is evident that the water will rise by hydrostatic pressure until it has att«ined the same level as in the chalk beds below, and if the surface of the ground at that point be below this level, the water will rise to the surface and overflow as at (? or //, which it did a few years ago in tlie valley of the Thames between London and Bient- ford, though it is said that latterly there has been a:i average fall of about two feet per year in the wells of the London basin, so that in many of iho.* wells Plati: \' ARTESIAN WELL. ;;ItENELLE, PAIUS, FRANCE. See payc 1C3. ARTESIAN WELL. 163 ARTESIAN WELL. Fig. 375. Section of the London Basin, which formerly overflowed the water is now raised ty pumps. At St. Ouen, jn France, water is brought up from two strata at different levels, the ascending force of the water from the lower stratum being greater than that in the upper. Fig. 376. This is effected by means of two pipes, one within the oth- er, with a sufficient interval between them to allow the free passage of wa- ter. The smallest pipe brings up the water from the low- er stratum B to the level of the highe.'it part of the fountain b", while the water from theupperstra- tuni, which does not attain so high a level, passes up through the outer pipe to a' ; by this means, should the water from the low- er stratum be pure and that from the upper impure, the former may be brought up and discharged sepa- rately without be- ing mingled with or contaminated by the former. Both the.se streams are used for supplying the canal ba.sin at St. Ouen, which is aliove the level of the Seine. The well at Calais is 1,138 feet, and that at Douchery, in the .Ardennes, France, 1,215 feet, in (lipth. The Englisli wells are of less depth, vary- ing from 70 or SO to 620 feet. The fountains in Trafalgar Square, London, are supplied Viy wells of this kind, 393 feet deep. Tliose of London are all in the chalk, and it is believed that by deeper boring, so as to reach either the upper or lower green-sand foimations, a more ample supply of water could be obtained. WeU of St. Ouen. The essential apparatus for boring as generally practiced consists of an auger or borer attaoheil to rods (which are successively screwed on to eacli other as the work progresses, and which atibnl a measui-e for the depth of the boring), and tubes of an exterior diameter equal to that of the well, which are pu.-hed down one after another to prevent the caWng in or filling up of the well by earth or rock. One r^ the most celebrated artesian wells is that at Gieneiie, a suburb of Paris, which took nearly seven years and two months of difficult labor to complete ; it is 1,602 feet in depth, and when the water-beai'iiig stratum of green-colored sand was reached, the water wns discharged at the rate of upwards of 880,000 gallons in 24 hours ; the force w.os such that the water could be carried to a hight of 120 feet above the surface. The temperature of the water from the depth of 1,802 feet was considerably higher tlian the ir.ean temperature at the surface. In the cellars of the Paris Observatory, at a depth of 94 feet, the ther- mometer was found constantlv to remain at 53°.06 Fah. ; in the chalk, at a de'pth of 1,319 feet, it marked 76°.3 ; in the gault, at 1,6.57 feet, 79°.6 ; and the water flowing from the well has a uniform tem- perature of 81°.8, indicating a rate of increase of 1°.7 for each 100 feet below the limit of constant temperature. The springs which supply the King's Bath, at Bath, England, have a temperature of 117°, and the spring of Orense, in GalUcia, has a temperature of 180° Fah. The artesian Brine-well of Kissingen, in Bavaria, was begun in 1832, and in 1850 water was reached at 1,878 feet. The depth reached by farther boring was about 2,000 feet. The water has a temperature of 66° Fah., and issues at the rate of 100 cubic feet per min- ute. The ejecting force is supposed to he derived from a subterranean atmosphere of carbonic-acid gas, acting with a force of 60 atmospheres. The tubings are concentric, water rising between the outer and middle tubes, passing down between the middle and inner tubes to the beil of rock salt, where it is saturated, and then raised in the middle tulie to the surface. The artesian well at Passy, near Paris, is proba- bly the largest well of the kind that has ever been sunk. It is carried through the chalk into the low- er trreen sands, which were readied at a depth of 1,913 feet, the bore finishing with a diameter of two feet. ARTESIAN WELL. 164 ARTESIAN WELL. Six years and nine months were occupied in reach- ing the water-beaiing stratum, when the yield was 3,349,200 gallons per Jay of 24 hours, subseijuently increased to 5,582,000 gallons, and then continued at 3,795,000 gallons per day. Tlie total cost of the well was £ 40,000. It was lined with solid masonry for a depth of 150 feet, then wood and iron tubing was in- troduced to l,804feet from the surface, and below that there was a length of copper pipe pierced with holes. The variety of boring tools which have been eni- )iloyi'il in niiiking artesian wells is very great, and the utility of some of those figured and described in works on the subject, if one may be allowed to judge from their shape and appearance, is very question- al)le. The mode adopted by the Chinese, who have for many ages been in the habit of boring for salt or fresh water is one of the most primitive. Their wells are often from 1,500 to 1,800 feet deep, and bored in the solid rock. .\ wooden pi]»e fivi' or si.\ inches in diameter inside is sunk into the earth, and covered with a stone having the same aperture as the pipe. A steel tool weighing 300 or 400 pounds, concave above and rounded beneath, is suspended by a cord from the extieniity of a lever and lowered down the tube ; by leaping on the end of the lever, the piece of steel is suddenly elevated about two feet and allowed to fall by its own weight, being Fig. 377. partially rotated at each movement. When S three inches of rock have been crushed, the steel is raised by means of a pulley, bring- ing with it the material which has accumu- lated on its upper concavity. Should the attachment of the steel head be broken, another steel headLs employed to break the first, an operation perhaps requir- ing months. Under favorable circumstances it is said nearly two feet of rock may be penetrated in 24 hours. L_j A modification of the above has been em- cL-ba ployed in Europe, in which the upper part RockDriU.of the tool is inclosed in a cylinder (see Fig. 377). These are suspended by a rope, the twisting and untwisting of which imparts a sutfi- Fig. 378. cient circular motion. When theapparatus is with- drawn from tile Ijole, the lower end of the tool closes the bottom aperture of the cylinder, which brings up the mass of comminuted rock to the surface. A conmion mode of boring is shown in Fig. 378. Two men walk around and turn the handle of the boring-tool, which is screwed into an iron rod. In moderately soft ground the weight of the two men and the rotation of the handle will cause the boring-chisel to penetrate, but in rock it requires to be hammered down, the men shifting its iJosition from time to time to enable it to act on a fresh portion of the rock. This operation is great- ly facilitated by susjiending the boring-rods Fij; .379. from a beam, fi.xed at one end and worked by a man at the other, assisting by its elas- ticity the ettbrts of those below in alternately raising and depressing the tool to give it the necessary pounding motion. When the hole has by this means been opened as far as the length of the tool will allow, it is withdrawn, and a valved cylindrical auger (Fig. 379) in- troduced, which being turned, the valve is opened by the pressure of the comminuted rock or earth below, and fills the cylindei', which is then withdrawn. See Auger ; Earth-boring. . ;f„;,. For raising and lowering the apparatus, a Clearer. tripod formed by three poles is erected over the mouth of the pit, from which a block and at- tached tackle is suspended ; this is made fast to a claw, represented at Fig. 380, which is passed under the shoulders of the upper rod. When this is raised sufficiently, a fork is passed under the shouldei's of the section below, the ujjjier one is detached by means of a suitable wrench, and the lifting again proceeded with. Instead of the F'g 380. springing beam, a windlass is sometimes em- ployed for giving the percussive motion to the tool ; several turns of the suspending rope being taken around the windlass, the friction of the rope will be sufficient, when ' aided by the strength of a man having hold of the end of the rope, to prevent it from slipping when the windlass is turned, the man taking up the slack and aiding the up- ward motion. When the whole ajiparatus p„^. is raised a short distance in this way, the claw. rope is slacked, and the apparatus falls with its whole weight, penetrating and crushing the rock below. The windlass is kept constantly in motion in one direction, and the percussive motion is main- tainele. Sir Robert Barker's description of the observatoi-y ASTRONOMICAL INSTRUMENTS. 174 ASTRONOMICAL TELESCOPE. rii. 399. W ' --_~-~"--ili^-; I^'uiil'e Obsfrvntory at Benares. of B 'iiares is as follows : " We entered this buililin;;, ail I went up a staircase to the top part of it lu-ar the riv.'r Ganges, that leil to a large terrace, where to ni/ surprise and satisfaction, I saw a number of instru- niMits yet remaining in the best preservation, stu- p Mulously large, iuiniovaljle from the spot, ami b'.iilt of stone, some of tliem being upwards of twenty feet in hight ; and thoii^li they were said to have be>n erected many hundred years before, the graduations and . It was the first good steam-engine on a working scale, and is the founda- tion of the Cornish engine. The present form of the engine has Watt's improvements. In it the steam from the boiler is conducted be- neath the piston, rather allowing it to rise than ac- tually lifting it, as the weight of the pump-rod causes the pump-plunger to desceml. The etiective stroke is obtained by the .condensation of the steam beneath the piston, when the pressure of the atmos- phere on the latter lifts the pump-rod and the water. In another application of the engine, the atmos- phere raises the pump-rod, and the weight of the lat- ter /oco'.? up the water. The illustration shows the old atmospheric engine, 12 Neiccomen's Atmospheric Engine. in which water was injected into the cylinder itself for the purpose of condensing the steam below the piston, in order that the pressure of the atmos])here might be availed to force down the jiiston and make an ett'ective stroke. The piston-rod P is connected to one end of the working- beam. The piston is shown as rising in the cylinder C, steam being ad- mitted to it by pijie S and valve 1'. When the jiiston has attained its ma.xiniuni bight, the valve I' is closed, shutting off the steam, and the valve D is opened, admitting water at the injection-aperture. The water speedily condenses the steam, and the piston is depressed by the weight of the atmosphere. The water escapes by the pijie E to the cistern called the hot-iidl, whence it is drawn for the sup- jdy of the boiler. The valve i^ opens outwardly to allow- the water to escape. The air escapes by an- other pipe at the valve-way G. The valves of this engine were originally in the form of faucets, which were turned by hand at tl;e ]u'oper times, as we see in Worcester's, Pa] ins, and Savery's engines. The same jilaii was adoiited in Newconien's until an ingenious l.oy, Hiinii hiey Pot- ter, being placed in charge, devised in ITlii a nnans lor connecting the lever-liandles of the fpigots to the working-beam, so that the motion of the latter was the means of opening and closing the lespective valves at the proper times. To the engine of Newccnien, Watt added, among other improvements, the separate condenser and the air-pump. By the former he Fig. 407. avoided the cooling of the cylinder at each down stroke of the piston ; by the latter he made the vacu- um beneath the piston more perfect. In the im- proved form the steam is admit- ted by pipe .S'and valve B; A is tlje cylinder of the air-pump which ejects the water, steam, and air resulting from the in- jection of water into the con- denser at E. In starting the engine, the pistons of the cylinder and air-pum)i being both u]i, any Wall's Atmospheric Engine. accumulation of water at the bottom of the latter is drawn off by the faucet F, which is then closed. The valve B is then raised above the steam-pipe ,S, so as to fill the cylinder, condenser, and passage D with steam, which ejects ATMOSPHERIC GOVERNOR. 178 ATMOSPHERIC HAMMER. the air at the valve Q. The slide £ is then lowercil, so as to shut otr the siipiily of steam ; tlie injection- faucet / is opened, discharging water into the eon- denser £, causing both pistons to descend. This is the ert'ective stroke of the engine, and as tlie piston of the air-pump descends, tlie results of condensation, together with some steam and air, flow through the valve-way between the condenser and air-pump chamber, to be ejected, as the piston A rises, on the return stroke. The rising of the piston A closes the intemiediate valve and opens the eduction-valve Q. The latent heat of steam being about 950", steam at 212° may be said to have 950° latent and 212° sensible heat, = 1162°. Steam mixed with 5J times its weight of water at 32° will raise the latter to iicarhj boiling lieat, though the water requires a great increment of heat to raise it a few degrees more, as so much heat becomes latent in passing to the condition of steam. The formula for construction of these engines is given as follows by Cre.sy. The cylinder has a diameter equal to half its length. The velocity in feet per minute should be 98 times the square root of tlie length of the stroke. The stroke of the air-pnmp should be half that of the cylinder, and the diameter of the air-piston three eighths that of the .steam-piston. The area of the steam passage is : as 4800 is to the velocity in feet per minute, so is the area of the cyl- inder to the area of the steam passage. To ascertain the quantity of steam, multiply the area of the cylinder in feet by half the velocity in feet ; add one tilth for cooling. This result divided by 1480 gives the quantity of water required to sup- ply the boiler. Twenty-four times this quantity of water is re- quired for condensation. The injection-aperture should be one thirty-sixth the diameter of the cylinder ; the conducting-pipe one nintli. To ascertain the power, multiply 6.25 times the square of the diameter of the (cylinder in inches by half the velocity of the piston in feet per minute ; the produ't expresses the elfectivj power, or the number of pounils elevated one foit high per min- ute ; the liorse-[iower is found by dividing the result by 33,000. At-mos-pher'ic Gov'ern-or .in apparatus for governing the motion of machinery by means of an imprisoned body of air subj<>cti'd to pressure. The illustration shows one foiin of apparatus in whicli the brake-lever D may be brought into contact with some moving wheel of tlie nricliine to be regulated. The pressure of the air in the cylinder A upon the Fig. 408. Atmospheric Govrrnor. piston C is the measure of the power brought upon the brake D. This pressure niav be decreaserl by allowing air to escape throngli tlie stop-cock F, or increased by the action of the valved piston B, b'. At-mos-pher'ic Ham'mer. A power-hammer driven by the force of coin]n'es.sed air. In some cases the air is employed merely to lift the hammer ; in other cases air is also employed as an adjunct in the effective stroke. In the latter case the operation is much like that of the steam-ham- mer, the main difference being in the substitution of air for steam. In Hague's English patent some forty years since, an atmospheric hammer is shown, in which tlie helve is raised by the pressure of tlie atmosphere be- neath a piston above the hammer-lielve, the air be- ing exhausted from above the piston by means of a pump ; the hammer falling by its ownweight when the air is admitted above the pistpn. In Fig. 409, a b is the hammer turning upon the fulcrum at 6 ; c the anvil ; d a cylinder situated immediately over the hammer ; e the jiiston eoii- nceted with the hammer by the bar /and the slings g ; h a slide-valve worked by the lever I, which is Fig. 409. Hague^s Atmospheric Hammer, struck by a pin on the bar/ when the piston arrives at the top of the cylinder, depressing the valve so as to shut off communication with the air-pnmp and admit atmospheric air above the piston, permit- ting the hammer and piston to fall by their own weight. Towards the close of the descent, the hammer, by means of a line attached to it and to the lever /, re- verses the position of the latter and of the slide- valve, thus re-opening the communication between the cylinder and the air-pump, h is the ]iipe leading from the air-pump to the cylinder ; m is a cock for shutting oft' the communication with the air-pump when the hammer is not at work ; n ii are spanners for opening and shutting the cock. The atmospheric lianmier (Fig. 410) has an air- pump and hammer combined in the same frame. e is the band-wheel which derives its motion /] from the motor, — steam or water, as the case may be. v is the pitman, and p the piston op- erated by a wrist on the band-wheel c and condens- ing the air in the cylinder o. The compressed air is stored in a reservoir a h, and conducted to the valve-chamber. In this chamber are a slide-valve /■ and stationary valve (/ d', the former opejated by the valve-rod w friuii the friction-wheels y d. Tlie head of the hammer h is attached to a piston (7, which works in the cylinder/, into which air is admitted — like steam to a double-acting .steam- engine — alti'rnately above and below- the piston. The friction-wheel V is spline-keyed upon the shaft ATMOSPHERIC HAMMER. 179 ATMOSPHERIC RAILWAY. Fig. 410. rod /; and its stroke by tlie adjustniciit of the wrist as the oraiik-shaft. B is the standard of tlie frame. The hammer (Fig. 412) derives tlie decision of its blow from tlie force of Fig. 412. Atmo-pheric Hammer. d, and is adjustable upon the latter longitudinally, so that its perimeter shall come in contact with the under side of the wheel y at points more or less dis- tant from the axis of the last-mentioned wheei. In this way the valve is made to admit more or less air to the cjdinder according to the force reiiuired and the duty to be performed. If the wheel b' be near the center of wheel i/, but little motion is im- parted, the stroke is quick, and the blow light ; but if the wheel V is carried nearer to the periphery of the wheel (/, the hammer is slower in its motion, and 11 more forcible blow is given. The valve-plate cV rf'is adjustable, but not involved in the ac- Fig. 411. wheel K. The hight of the hammer F above the anvil is graduated by the adjustment of its piston- Pneitviatic Hammer. The equilibrium line of shows tliat the steam compressed air. The hammer-head is at- atched to a piston B moving in a cylinder F, the latter being con- nected by a jiitman D to a crank -wheel E ro- tated by the motor. As the cylinder as- cends, air enters the holes in the cylinder, and the air being com- pressed below the pis- ton, the hanniier is lifted. As the cylin- der de- scends, air is com- pressed above the piston, and is stored up to produce a sudden blow, by in- stant expansion after the crank and con- necting-rod turn the bottom center. At-mos-pher'ic Line an indicator card, wliicl prcsMne is equal to that of the atmosjihere. At-mos-pher'ic Pump. One in which the pres- sure of the air forces water into the [ripe lielow the plunger. The usual foim of ///V-immp, thougli some lift-pumps elevate the water from immense depths in mines. The attempt in 1641 of a Florentine pump-maker to make an atmospheiic pumii which would elevate water 50 or 60 feet having failed, tlie Grand Duke asked Galileo to account for the failure. His leply was not to the purpose, but Torricelli ten years afterwards explained the cause. Galileo was by this time "in his grave." Malice had "done his worst .... nor steel nor poison " could " touch him further," At-mos-pher'ic Rail'Tvay. The idea of convey- ing carriages in a tube by means of atmospheric pressure seems to have originated with Dr. Papin, of Blois, in France, about the end of the .seventeenth century. This extremely versatile man was the first to apply steam to lai.sing a piston in a cylinder. He was the inventor of the Digester, and to this was first applied the lever-weighted safety-valve, also the Doctor's invention. The experiments actually en- tered upon by the philosopher of Blois, in the mat- ter of comjiressed air, were princiiially diiected to the transmission of power thereby. See AlK as a Means of tkaxsmittino Power. He ])iaced air-compressing engines in positions where the compression could be effected by a fall of water, and pipes were to convey the air to the mine, where it was to be allowed to expand against a pis- ton and work a pump. For some reason the project failed in its execution, but has been more successful in other hands. The suggestion of conveying goods, parcels, and passengers by compressed air appears to have been rather a chancesuggestioii than to have been seriously entertained, and it has been again and again rei'ived in the 130 years that intervened between Papin ATMOSPHERIC RAILWAY. ISO ATMOSPHERIC RAILWAY. and Medhurst, who again urged the project about 1810. Medhurst, in ISIO, published anaccountof "anew method of conveying goods and letters by air," and in 1812 e.xteudeti the idea so as to jiroride for the transnussiou of passengers, whom he proposed to transport at the rate of tifty miles per hour. His project consisted of an air-tight tube, containing a pair of cast-iron whecl-traoks on which the carriage has to run. The carriage had the form of the tube and a certain amount of packing to prevent the leakage of tlie air, which was condensed behind it and formed tlie projielling power. His calculation was as follows : — To obtain a speed of 50 miles per hour, in a tube si.K feet in diameter, would require a constant im- pelling force of 861 pounds moving at the rate of 73 feet per second, eipuil to the power of 180 horses. Taking the consumption of fuel of a steam-engine of that size at 12 bushels of coal per hour, three tons of goods niiglit thus be conveyed 50 miles at a cost of V2s. and at the speed mentioned. The project fell ujjon tlie dead ear of the public. Twelve years afterward the idea was revived in a changed form. Retaining the tube and carriage of Medhurst, Vallanee, in 1S24, obtained a patent in England for his modified plan, which consisted in using a partial vacuum in front of the carriage, al- lowing tlie natural atmospheric pressure in the rear to iiiijiel the carriage. In this he dili'ered from Papin and Medhurst, who proposed a plenum in the rear, and not a vacuum in the advance. Vallance's tunnel was to he of iron or vitrified clay, and he constructed a short tube in his garden at Brighton, which worked on the moderate scale on wliicli it was applied, and was occasionally no- ticed in the journals of the day. So far all the inventors have proposed that the carriage shall travel in the tube in the manner of a jiiston. The ne.vt jiroposition introduces a new fea- ture. In 1S34, Pinkus, an American citizen residing in England, took out a patent for an apparatus whie'i he termed a Pneumatic Railway, ami laiil the foun- dation of most of the successful applications of the atmospheric principle w'hich have since been intro- duced. Pinkus's patent embraces a main with a continu- ous longitudinal .slot on its upper surface, and an elastic gi'avitating valve to fill the slot. The tube was to be about forty inches in diameter, laid down between a jiair of rails on which the carriages were to run, and having within it a piston attached by a vertical arm to the leading carriage of the train. The vertical arm passed through the slot in the up- per part of the tube, and displaced the valve as the jiiston advanced, the valve closing in the rear of the arm after allowin" some air to enter. The valve consisted of a thick cord saturated with a composi- tion of wa-\ and tallow. (-'legg patented some improvements in 1839. The valve works on a hinge of leather or other fle.\ible material, which is practically air-tight, sim- Fig. 413. fig. 414. CUgff^s Valve dosed. Cleg^^s Vah\' open. ilar to the valves commonly used in air-pumps ; the extremity or edge of the valve is caused to fall into a trough containing a composition of beeswax and tallow, or other substance which is solid at the tem- perature of the atmosphere, and becomes lluid when heated a few degrees above it. An outer flaji of sheet-iron / covers the leather valve when the slot in the tube is closed behind the colter C, and is raised before the colter by the ob- licpie roller /), Figs. 414, 415. The tube ..-I was coated inside with hard tallow, to make it ]ierfectly smooth, and the piston £ was furnished with a I'od S, about 14 feet long, to which were attached rollers IT H, which presseil open an air-tight valve along the top of the tube as the pis- ton advanced. The piston was attached to the first, or driving, car by means of a colter t', and to the dnving car was attached a copper vessel, several feet in length, heated with coke, for the purpose of melt- ing tlie composition after the valve had been pressed down by the closing roller. The valve behind the lifting-bar was held up for a sufficient time by the rollers H H, to allow the air to pass in behind the piston. The pipe was divided by valves into three-mile sections, a steam-engine working the air-pump of each. The main was cast in sections nine feet long, joined by an oil cement. An experimental line was laid down at Worm- Fig. 415. □ □ nnn □□□□ nnnD Cleg^'s Atniof^theric Railway. ATilOSPHEEIC RAILWAY. 181 ATMOSPHERIC RAILWAY. wood Scrabs by Clegg and Samuda. The line was half a mile long, with a rise of 1 in 120 for a part of the distance and 1 in 115 for the remainder. The diameter of the main was nine inches. The exhaus- tion was produced b}' means of an air-pump 37 inches in diameter and 22 inches stroke, worked by a conden.sing engine of le-horee power. This arrangement was employed from 1844 to 1855, on the line fi-om Kingston to Dalkey, Ireland, IJ miles long. It is stated that an exhaustion of 15 inches couJd be produced in two minutes, and a rate of 50 to 60 miles an hour could be obtained. The rise is 71^ feet in 3,050 yards. Tlie diameter of the main was 15 inches. The double-acting air-pump was 66J inches diameter, with a stroke of 66 inches. It was worked by a high-pressure condensing-engine of 34 inches diam- eter and 66 inches stroke, working expansively. The stoppage was effected by a powerful brake, and, if necessary, by an arrangement operatable from the car, by which the ralve was opened in advance, so as to destroy the vacuum. Railroad engineers expressed veiy various opinions on the feasibility of the new project, Brunei and Stephenson took opposite sides, as usual, and the plan was tried in South Devonshire, on the Croydon R-iilway, and elsewhere. It eventually failed by reason of complexity and liability to . get out of order, leakage of air im- pairing the vacuum. The advantages are : facility in ascending heavy gi'ades, rendering less cost necessary in leveling and grading ; and security against collis- ion. Another form of conveying the mo- tion of the piston in the atmospheric tube was invented by Pilbrow, and was intended to avoid the continu- ous opening in the tube, and the necessity for the valve which closed it on the Pinkus principle. Pilbrow made a toothed rack on the edge of his piston, which rack engaged with a series of pinions in air-tight boxes attached to the sides of the tube at short inter\'als. The verti- cal axes of these pinions passed up- Fig. 416. ward through stuffing-boxes, and at the top were provided with other pinions which geared into lacks on the sides of the carriages. Thus, the motion of the piston rotates the pinions successively as it advances along the line, and they comnninicate motion to the carriage. It is not known to the writer whether this device ever came into practical use. Keese and Nickel's Atmospheric Railway (Eng- lish) was designed to act by compressed air in a tube laidalong, underground, between thelinesof rail. Sta- tionary above the surface are certain standards with giooved sides, in which are elastic pipes fed from the reservoir-pipe below. Beneath the carriage to be driven aie roUei-s which are made to condense the elastic pipes into the hollowed sides, and the air, being admitted in the rear, expands against the ] eripheiies of the dnims lieneath the cariiage, and forces them to rotate and the carriage to advam-e. Henry's Atmospheric Railway, English Patent, August 7, 1845, specities a side .slit in the atmos- pheric tulie, and the longitudinal valve closed by the jiressure of a long liag or hose, inflated with air and protected by a shield of wrought-iron bolted to the tube. The vacuum in the tube is produced by first filling with water a number of large, close reservoirs con- Fig. 417 PiJbrow^s AtmosjAeric Railtcay. Elevated Raiiicay. nected with the tube by pipes and valves, opening the comuumication between the two, and then allow- ing the water to run off. The same mode of producing the vaoiuni was described in Aitken's English Patent, Fcbruarv 24, 1S44. In another application of the air, a tube laid throughout the line is filled with compressed air, and is used as a reservoir wherefiom coni|iressed-air locomotives may renew their supjily of air. This is suggested in connection with one foim of Elevated Railway. In one form (Atmospheric Elevated Railway), the tube, which extends the whole length of the railway, is filled with coni]iivssed air. for the supjily of the tanks on the cai-s, which fonn veservoii-s for the supply of the air whereby the aii-engines are driven. The tube at suitable intervals has valves and discharge-pijies for the supply of the engines on the care. The original proposition to use a tran.sportation- tube and compression or exhaustion of air for the conveyance of lighter articles of freight and lettei-s, has been ]iut in practice successfully. A company was formed, and a permanent line laid down in 1S59, for conveying parcels and light goods from the ATMOSPHERIC SPRING. •I ATOMIZER. SYMBOL. OLD. NEW. Cadmiuni, Cd. 56. 112. Cccsium, Cs. 133. 133. Caloium, Ca. 20. 40. Carbon, C. 6. 12. Cerium, Ce. 45.7 91.3 'yhloritw, CI. 35.5 35.5 Jhi'oinium, Cr. 26.1 62.2 Cobalt, Co. 30. 60. Columbium, Cb. 94. 94. Do]iper, Cu. 31.7 63.4 Didymium, D. 47.5 95. Erbium, E. 50.3 112.6 Fliioi-inc, F. 19. 19. Gluoiuum, GI. 4.6 9.2 Gold, Au. 197. 197. Hijdrocjcn, H. 1. 1. Indium, In. 56.7 113 4 Iodine, /. 127. 127. Iridium, Ir. 99. 198. 1 1011, Fe. 28. 56. Lanthanum, La. 46. 92. Li'ad, Pb. 103.5 207. Lil Ilium, Li. 7. 7. Jhignesiura, Mg. 12. 24. Manganese, Mil. 27.5 55. Jlercury, Hg. 100. 200. Jlolvbdeuum, Mo. 48. 96. Kioicel, Ki. 29. 58. Kitroqen, N. 14. 14. Csmium, Os. 100. 200. Oxygen, 0. 8. 16. I'lilladium, Pd. 53. 106. J'/iosphoruSy P. 31. 31. riatinum, Pt. 98.7 197.4 J^dfffSfiium, K. 39.1 39.1 Uliodium, Ro. 52. 104. Jiithidium, Bb. 85.4 85.4 liuthenium, Ku. 52. 104. Si-lenium, Se. 39.5 79. ■Silicon, Si. 14. 28. Sih-cr, Ag. 108. 108. t^odium, Ka. 23. 23. Strontium, Sr. 44. 88. Sulph\ir, S. 16. 32. Tantalum, Ta. 182. 182. Ti'lhirium, Te. 64. 128. Terbium, Tb. 37.7 75.4 Tlinlliiim, Tl. 204. 204. Thorium, Th. 59.2 118.4 Tin, Sn. 59. 118. Titanium, Ti. 25. 50. Tungsten, W. 92. 184. Uranium, U. 60. 120. I'ltiiitdium, r. 51.3 51.3 Yttrium, Y. 30.8 61.6 Zinc, Zn. 32.5 65. Zirconium, Zr. 44.8 89.6 Euston Square Station and the Post-Office in Evers- holt Street, London, and an e.xtension was opened in 1865. This realizes the dreams of Papin and the hopes of Medhurst, nearly two hundred years after the busy speculations of tlie first and fifty years after the disappointment of the second. A late act of Congress (1872) appropriates S 15,000 for a pneumatic dispatch-tube between tlie Capitol and the Government Printing-Otiice, Wiisliington. The pneumatic dispatch-scheme has been put in operation at tlie Crystal Palace, Sydenham, England, to convey regular passengers. The tube extends from the Sydenham entrance to the armory near Penge Gate, a distance of about a quarter of a mile ; and it is, in fact, a simple brick tunnel, nine feet high and eight feet wide, — a size that renders it ca])able of containing an ordinary raihvay-caniage. The piston is rendered partially air-tight by the use of a fringe of bristles extending nearly to the brickwork of the tunnel and its Hoor. A fan 20 feet in diameter is employed to exhaust or to force in air, and perhaps it is impossible to devise any other expedient so well calculated to answer the re.piired purpose. It must be rememliered that either a plenum or a vacuum e [uivalent to .5 of a:i inch of mercury is quite sutti'ient to jiropel even a heavy train at a high speed on a moderately level line. In the present instance the motive-power is supplied by an old locomotive borrowed from one of the railway-companies, which is temporarily mounted on brickwork. The tires have been removed from the driving-wheels, and these last put the fan in motion by straps. The line is a quarter of a mile long ; a very small portion of it, if any, is level, but it has in it a grailient of one in fifteen, — an incline which no engineer would construct oa an ordinary railway ; and as it is not a level line, so it is .not a straight one ; for it has curves of only eight chains radius, which are shorter than those usually found in exist- ing railways. The entire distance-, 600 yards, is traversed in about 50 seconds, with an atmospheric pressure of but 2^ ounces. The motion is, of course, easy and pleasant, and the ventilation ample, with- out b;'ing in any way excessive. See Pneumatic TrnrL.Mi riisPAi-rii. At-mos-pher'ic Spring. A spring formed by a confined liody of air either operating by means of a cylinder and piston or by an air-tight bag. It has been suggested for gun-carriages, to take the jar of the recoil, and also for railroad- cars. See Pnei'Matic Spitixo. A-tom'ic 'Weights. The appended list of chemical equivalents differs much from those of old- er and other authorities, but is offered as the best within the reach of the present writer. It differs also from a short list of chemical equivalents on page 66. TABLE OF ATOMIC WEIGHTS. Compiled according to the Latest Determinations, for the Use of the Sliff/eiits of the Srhool of Mines, Colitmbia College, Jan., 1872. BT C. F. CH-\NDLER, PH. D. Hyilrogen = ]. STMBOL. OLD. NEW. Oxygen, 0. 8. 16. Aluminium, Al. 13.7 27.4 Antiiiioni/, Sb. 122. 122. Arsenic, As. 75. 75. Barium, Ba. 68.5 137. Bismuth, Bi. 210. 210. Boron, B. 11. 11. Bromine, Br. 80. 80. At'om-i-zer. The atomizer is designed to re- duce a liquid into spray for disinfecting, cooling, or perfuming purposes. Several difierent modes of operation are adopted. One style consists of a blast of air presented at right angles across an opening in the end of a tube which communicates with a supply of the liquid. This acts somewhat on the principle of the Gitt'ard In- jector, raises the liquid, and by contact disperses it, reducing it to a fine spray. The contiguous air and fluid tubes are connected to the vertical or cup tube, so as to be reversible in relation thereto. The atomizer-tube is used to difl'use a cooled liquid in spray to render it more eflective in absorb- ing the sensible heat of a room or vessel. There are ATOlllZEU. 183 ATOMIZER. Fig. 418. many adapta- tions to boats, gi-anaries, hos- pitals, i'ruit- chanibei's, and for making ice. In tlie atom- b.er (Fig. ilS) the atomi2ing blast is ejected by an elastic bulb, and cross- es the orifice of the tube leading from the vessel of liquid, whose contents are thereby raised, and driven, in the form of spray, through the shield, which directs it upon the part where local an- iEsthesia is re- Alomizer. quired. The shield has a flaring and cj-lindrical portion, is hinged to the liq- uid vessel, and adjustable in relation thereto, and drains into the vessel. In another apparatus for impregnating the air with antiseptic vapors, to prevent infection and purify the atmosphere of hospitals, etc., a trough holds the antiseptic liquid, such as tar, carbolic acid, turpentine, etc., from which the vapors are to be generated. A frame contains a numlwr of verti- cal perforated plates, which, after dip)jing in the liquid, are supported in a raised position, so as to part with their vapors to the atmosphere. Fig. 419. Flfun/s Atomizer, In Fig. 419 the vessel is supported nn vertical pivots above a gas-burner, and contains a ilisinlecting liquid or perfume. When heat is applied, the vayior escapes by the hollow arms above, revolving the vessel, on the principle of Hero's ffiolipile, and dis- seminating steam and spray in the apartment. The apparatus is supported upon a pivot erected upon the frame of the Fig. 420. shade, which is secured to the' gas-burner in the usual man- ner. The atom- izer is also used in connec- tion with an air- carbureting ap- paratus. In the early and simple forms of inhalers the liquid was va- j)orized by heat, and this is a desirable condi- tion for some modes of treat- ment. In many cases, however, the increased temperature produces injurious effects. A means of changing the liquid into mist, which does not act on the Giflard jirinciple, as in the modem form of atomizer, is shown in Fig. 420. The rotary wheel has hollow, radial arms, terminat- ing in very small orifices, through which the liquid is thrown in jets by centrifugal action. The liquid is ejected against oblique plates attached to the ends oil' the radial anus of another wheel which rotates in a direction the reverse of the fonner. The contact of the liquid with the plates leduces it to a spray, which pen'ades the chamber in which the operation is carried on, and the jiatient is caused to breathe the mist either by a tube or otherwise. In the anffisthetic instrument for dental purposes, each tube is bifurcated, so as to reach the inner and outer sides of the jaw simultaneously, by the branch- es d d. The straight tube a carries the air-blast, Fig. 421. Atomizing Wheel, Cutter's Atomizer, and thus draws a curient of liquid whose rapid evap- oration prodncescold and local anaesthesia. The lower end of the bent tube b is dipped in the liquid, and it discharges at its end, while the air-tube oc discharges jnst in advance of it, producing a spray of the liquid. The atomizer is adapted for operation by hand or foot bellows (§ee Fig. 181). It consists of a hollow curved tube, made of German-silver, one e-xtremity of which has an adjustable conical ca)i, while the other pa.sses down into the bottle through a perfora- tion in the cork. A short distance above the cork this tube has another tube joined to it at right angles, and which is attached to the india-rubber tubing. "Within the second tube there is contained a capillary one, which extends from within a line or two of the extremity of the ca)i nearly to the bot- tom of the bottle, and beyond the bottled extremity of the larger tube. Xear its uppev extremity this capillary tube perforates a cylinder of metal, which almost completely occupies the caliber of the larger tube, and would entirely plug it up except that it has longitudinal grooves upon its surface. Pressure ATTACHED COLUMN. 184 AUGER. upon the haiul-ball forces air through tliu other ball, and so to the cavity of the curved tube. One col- umn of this air passes upward tlirough the tulie, and tlie other downward into the bottle. The up- ward column passes through the grooves in tlie cir- cumference of the plug into the cavity of the cap, and escapes through the capillaiy orifice at its tip. This column of air, passing over the extremity of the capillary tube, creates a vacuum in it, which is sup- plied by the liquid contents of the bottle, U|ion which one of the columns of air is pressing. The other colunm of air divides into spray the drops as they issue from the inner tube. The theaters of the Romans were fitted up with numerous concealed pipes, that passed in every dh-ectiou along the walls, and were connected to cisterns of water or to machines for raising the lat- ter. Certain parts of the pipes were very minutely perforated, and were so ari'anged that, by turning one or more cocks, the lii[uid escaped from them, and descendcil upon the audience in the form of dew or extremely tine rain. This elfectually cooled the heated air, and must have been exceedingly refresh- ing to the immense multitudes, especially in such a climate as Italy. " The dining-roonn of Nero's golden house were ceiled in such a manner that the attendants couhl make it rain either Howers or liquid perfumes. At one feast 100,000 crowns were expended in perfumed waters." — Ewb.vnk's fft/drauHcs. It is possible that the Romans extinguished flames in the same manner. See also .Sir William Congreve's English patents Nos. 3201, 3606 ; 1809 and 1812. At-tached' Col'umn. (Architect it re.) One partially imliedded in a wall. .\n inserted column. At-tach'ment Screw. A bimling screw. At'tic. .\n ujiper story, when the ceiling is hor- izontal. Otherwi.se it is a qurret. At'tle. {Miiiinj.) Rubbish containing little or no ore. Synomyms ; ruUle : a-lil/: fdlul. At'wood's Ma-chine'. A sci- Fig. 422. entilic apprratns to illustrate the theory of accelei'ated motion. It consists of a wooden column, about 10 feet high, resting on a base and supporting a series of anti-fric- tion wheels, which support a large central rolhu', over which passes a cord having equal weights at each end, so as to be in ejitililirio. By means of a graduated staff at one side the rise of one and fall of the other weight are indicated in feet and inches. A small additional weight, being added to one of the large weights, causes it to descend with ,a velocity due to its excess of gravity over the other ; and this being very small, the motion is eorrespondingly slow, ren- dering the resistance of the air in- appreciable, and enabling the rate of descent to be ascertained with great accuracy. The counterpoise weights of this apparatus enable the constant accel- eration of speed caused by gravity in a falling body to be shown and measured within the space of a few feet more accui-ately and satisfacto- rily than could be done by the fall Atwood's Machine. o( a weight not thus counterpoised from a considiu-able hight. It may also be employed to illustrate the laws of retariled motion, impact of bodies, and resistance of lluids, as well as other phenomena of a similar nature. Alhazen the Saracen, A. D. 1100, in his •' Hook of the lialanee of Wisdom," considered the .subject of gravity, and asserted that it diminished with the distance. It was reserved for Newton to deteimine that it decreased as the square of the distance. Alhazen dctennined correctly the relation be- tween the velocities, spaces, and times of falling bodies. The University of Cordova was the intel- lectual center of Enrojie in his ilay. The Khalif Alkamen's library was so large that its catalogue tilled 40 volumes. The people of Cordova could walk paved streets at night 10 miles in a straight line, by the light of ]iublic lanijis, when Loudon and Paris were dark and disnuil mud-holes. Galileo, bom 15d4, considered the subjict of acceleration of force, and determined the relation between the spaces of descent and the times. He used inclined ])laiies, by the aid of A\hieh he con- veniently diminished the velocity without changing the nature of the result. Au'ger. The lirst boring-tool may be assumed to have been an awl of some kind. Pliny states that Dffidalus invented the gimlet, — 1240 B. r. It was destitute of a screw-point, but it may have had a hollow pod, and a ero^s-head Ibiniing a handle. Awls are shown in Egyjitian tombs of 17n0 and 1490 B. c. The screw-point was added to the gim- let in course of time, and, witliin our own recollection, the twisted shank, which makes it .'elf-discharging. This hint was taken Ircm the anger juoper, which may be called a magnitied gindet, now that their sjiccific features have become so closely assimilated in foira and fum'tion. The anger (/c/'ci/'o) was a Greek tool. The Teredo vinalis is nnich older still, and carries an auger in his head ; — a great liore he is. From the early descriptions, the auger appears to have been considered a shipwright's tool. It for- merly had a curved, sharpened end, and a concavity to hold the chijis ; this was a ]iod auger. To this a lip was subsequently added for some kinds of boring, and in course cf time the depression gi-ew into a spiral, which allows the chips to escape while the boring proceeds, instead of withdrawing the tool as the pod becomes tilled. The Tvistid AiKjer is an American invention, and was made by Lilley, of Maustield, Connei'tieut, about the beginning of the present century, and afterwards by Gurley, of the sanie place. Fig 423. Fig 424. VHommedieu*s Au^er. Sftettrr\^ Amrriean Ati^er. AUGER. 18c AUGEB. Cook^s Auger. Fig Fig. 425. Augers may be elassilied as au- gers ; hollow angel's ; annular au- gers ; tajx'T angers ; augers \yith secondary borers, reamers, or coun- tersinks, or having expansive cut- ters. Auger-gages, auger-handles, and machines for making angers, will be considered separately. L'HoMMEDiEU's Auger, 1809 (Fig. 423), has two pods, two cut- ) ting-lips, a central screw, and a twisted shank. It is hardly fair to say that it is ]ierfect of its kind, as many imiirovements have fol- ' lowed ; but it is, on a smaller scale, like Stephenson's "Rocket" En- gine, the type of its cla.s3. The form of auger wliich in England is called the "American" pattern ', was patented by Shetter, March 1 21, 1831. It "has a spiral blade around a cylindrical core, and was long a favorite. The " good work- men " who "never quarrel with their tools" do not seem to have retained tliis form in the estima- tion it once held. It probably oB'ers more impedi- ment to the discharge of the cliips than does the shank made from a flat blade twisted into a spiral. Some auger-shanks have an in- crease twist as they recede from the point ; I this gives a greater freedom of discharge by I increasing the caliber of the canal as the chips ascend. In the auger (Fig. 425) the cutting-lips 1 commence at the screw or point, and extend / therefrom nearly at right angles, until about half-way from the center to the outer ) point, and then curve upward and forward, giving a nearly semicircular fonn to the I outer portion of the lips, which are curved ' in the horizontal and vertical planes. The auger (Fig. 426) permits the forma- f tion of cuttiug-lips at any point ou the length of the siiii-al, by cutting olf the twist at any point, in a plane vertical, or near- ly so, to the axis of the auger, and then Kasion's sharpening its edges. The front surfaces Au^er. of tlie twist are concave, and the rear convex. The Sfotting Auger cuts laterally, the work being fed against its .side. It is used in wood- mortising and slotting machines. The twist is formed into a numlier of chisel-shaped lips Fig. 427. vising from the edge of the twist and pre- senting sharp edges in the direction of the bore of the auger, so that the wood may be cut laterally if pushed against the instm- ment after the hole has been bored to a suffi- cient depth for the proposed mortise or slot. The end-lips may be made chisel-shaped or hollow like a gouge, as desired. If the anger ' or bit be held in the rapidly revolving arbor of a mortising or boring machine, the mortise I may be cut at full depth, at one operation, by moving the wood laterally against the auger. The corners of the mortise are after- wards cut out by a cliisel. HoUotc Augers are used for fonning tenons on the ends of spokes, bedstead-rails, chair Slatting rounds and legs, table-legs, and many otlier Aiig^!-. articles. Those on a more extended scale, wliich allow the material to pa,ss clear through them, are properly tuniing-machines, ami are adapted for making scythe-snaths, broom-handles, etc. The hollow auger, as a Fig. 428. tool, operates to a certain length on the object, after which the auger or the ob- ject is withdrawn. Means for measuring the stroke are fre(iuently found in the construction of the tool, as by the depth of the socket ; but other means may be used, and are known as aw/er-gages. This tool (Fig. 428) is adjustable for boring holes of different sizes. The ro- tary lUsk has eccentric slots acting upon pins inserted into the backs of sliding cutter-heads, so that they are driven out or drawn in simultaneously, and fas- tened by a jam-nut, which holds them in the required adjustment. The above is adapted to be used as a bit in a brace. Fig. 429 has cross-han- dles like an auger. The cutting-tool is so attached as to project within the opening, and the size of the tenon is regulated by the adjustment of the angular rest. The tool has the usual auger-handles, in which respect it differs from most of its class. They are Fig. 429. Hollow Auger. HoUow Auger. usually attached to braces or to mandrels rotated in bearings similar to those of the lathe-head. A dozen others might be cited, but these are probably sufhciently descriptive. Fig. 430. Annular Augers cut an annular groove,' leaving " land" on the inside and outside of the channel. The example (Fig. 430) is adapted for boring cylindrical blocks out of a board, the lower edge of the tube being serrated. Fitted inside the tube is a cylin- drical plug with a central point. On the re- duced shank of the plug is a spiral spring, which keeps the point extended, except when pressure is applied to the tool in boring. The cutters on the end of the tube (Fig. 431) make an annular groove and leave a core of wood in the center,' the chips lieing with- drawn continuously by the .spirjil blade on the tube. The cutting-lips start at the pe- riphery of the bit, and extend towards the center in concave lines, till they terminate at ^g the inner portion of the tube, where their ^3 direction approaches a line parallel with the LJl axis of the auger. In a subsequent form a ' number of tulirs are arranged concentrically, j„„u/ar so as to cut concentric, annular grooves sun- Auger. AUGER. 186 AUGER. Fi^. 4.31 Fig. 432. b ^ p. Annular Borer. ultaueously, and produce a nest of cyl- inders out of the same stick or board. Yet another form is found in the tool (Fig. 432) sometimes known as a button-tool. It has an upiight cen- ter standard, with a line feeding-screw on the lower end. The cutter i-s at- Jnnalar Auger, taclied to a radial arm, and is adjust- able, so as to describe the diameter required for tile hole. The cutter is fed to its work by the thread on the standard, and the chips are ejected by the Fig. 433. Kirbifs Taper Auger. curved neck. Taper Au- gers are used for reaming out b u n g h 1 e s , making butter- priuts, etc. The center bit boresahole, and is succeeded by the taper ream- er, which has a throat for the chips, cut througli from the eilge of tlie bit on one side to the opposite side of the stock. The Bung- hole Scdmcr (Fig. 434) has a tapering pod, and a cutting- 1 i p on one side ; the lower end is closed to receive the chips, and is open at the top, except a bail to which the handle is fastened. On one side is an adjustable gage and inde.\ to determine the size of the bore. The ordinary form of bunghole borer is shown in Fig. 435. This lias a vohite-shaped blade with a sharpened, salient spiral edge and a gimlet jioint. It, like most of its class, is for reaming out bung- holes and taps. Augers are sometimes provided with secondary borers, reamers, countersinkers, or expansive cutters. In Fig. 436 the reamer or secondary borer is formed in two pieces, and is clamped to the auger- shank at the reipiired distance from tlie end of tlie tool, and at the same time is adjustable to ream out a hole of tlie recjuired diameter. Tlie clamp is shown separately in tlie upper portion of tlie figure. In Fig. 437 the countersink is attached to the auger-shank at the reiiuired spot, but does not entirely surround the shank, the opening correspondiiigwith the twist of the shank, so that the discharge of chips is not interrupted. In Fig. 438 the plate is received into a longitudinal slot in tlie auger- shaft, and one end is secured by a tem- per-screw. A pin, passed through Fig. 434. Bunghole Reamer. one in the series of holes in the shaft, engages a hole . in the oblique series in the plate, and determines Fig. 436. Fig. 436. Counter-Borer. Fig. 437. Crocker^s Taper Auger. the radial adjustment and conse- I quently the diameter of hole bored by it. The shanks and turned cutting- edges of the expanding bits in Fig. 439 pass through a mortise in the head of the tool, and are secured to their adjustment by a key. Their radial adjustment adapts them to bore holes of vary- ing sizes. In Fig. 440 the cutter is adjustable eccentrically, and is held by a dovetailed groove and tenon. The cylindrical core is solid, and the center point is removable. The spiral has a sharp edge. The ad- justment of the cutter on its ec- centric pivot varies its radial sweep in boring, and it is thereby adapted to bore a hole of the re- quired size, within tlie limit of its capacity. Among the other uses of au- gers may be mentioned that of felling tri'es in the Mammoth Grove, Calaveras County, Califor- nia. This grove is in a gently BS/j sloping valley, heavily timbered, situated on the divide or ridge be- tween the San Antonio branch of the .Stanislaus Hiver, ill latitude Courttersink. 38' north and longitude 120° 10' west, and .'i,200 feet above the level of the sea; here, within an area of about eighty acres, and high above the surrounding trees of the forest, can be seen AUGER. 187 AUGER. rig. 438. ^ ^ Expanding Auger. the stately heads of these erergreen forest giants, the Sequoia gigarUea. These trees are now gi-owing in many parts of rig. 439. Great Britain and France, from Califor- nia cones or burs, and no native trees are equal to them in the rapidity of their growth. There are twenty of these trees that will average 25 feet in diameter at the ba.se. One of the largest now standing is called the " Mother of the For- est, "and has been stripped of its bark 116 feet high, and still measures in circumference at the base 84 Fig. 440. Erpansihle Auger. Expansible Anger. feet ; 20 feet from the base, 69 feet; 70 feet from the base, 43 feet 6 inches; 116 feet from the ba.se, 39 feet 6 inches ; circmnference at the base, including bark, 90 feet. Itshight is 310 feet, ami it is supposed to be 3, 000 years old ; the average thickness of the bai-kis 11 inches, but in some of the trees it is as much as 22i inches. The " Big Tree," as it was called, contained 500,000 feet of inch lumber. It was felled by five men working 22i days, making 112i days' labor to fell one tree. This tree measure The second consists of a tube which is driven or screwed into the earth, and is generally intended to remain as the permanent ]iump-tube ; for this purpose it has a solid jioint, to withstand the contact of the obstacles which it is e.v- pected to pierce or displace, and holes which are unclosed to admit the water after the wet stratum is reached ; these will lie explained under their appropri- ate heading. McMahen's ''''"^ third are devices of a more ex- Earih-iorin' tensive character than mere hole-diggers. Auger. and are used in sinking Artexiaii, wells, oil and salt wells, and in boring for mineral lodes. Au'ger-fau'cet. A faucet with an attached auger, by which tlu; necessary hole is made in the head of the cask. As soon as the auger has about penetrated the Fig. 444. stave, a blow is given to the auger, wdiich breaks away the scale of wood, and the same blow settles the auger into its position. The bit is attached to the faucet, and is projected or retracted by a rack on its shank within the faucet, actuated by a thumb-screw. A frustal projection on the cap alforils means for oper- ating thi- devici; by a brace. Au'ger-gage. A device to be attached to the shank of an auger to limit the penetration. Tlie countersinks of some of the comimund augcM-s and the sockets of the hollow au- I gers cU'ect the sjirae purpose in some cases. The example (Fig. 445) has a pair of bars, secured by temper- screws to the spiral shank, so as to form a gage of depth. Fig. 445 Auger- Gage. Anotlier fonn has a tel- escojiic tube attached to the shank, hirger in diam- eter than the worm, and adjusted as to length by means of two temper- screws whose <*nils bear against the spiral shank. Fig. 446 is for making tenons of a given length on the ends of spokes, etc., and is adajited for hollow augers. The rear of the stock has a thread traversed by an adjust- able screw, which, by eon- tact with the end of the stick, detemiines the depth of the hole and consecjuently the length of tenon to be cut. A jam-nut secures the ad- justment. Au'ger-han'dle. The tang of the ;uiger is in- Fig. 446 Gage for Hollow Auger. serted perpendicularly into its handle, and the end is usually clinched or riveted on to a washer. Means have been contrived for making the auger removable from its handle, so as to make one of the latter answer for vaiying sizes of augers, and to dislocate the parts for convenience of stowage. The devices for this purpose consist respectively of a slotted sleeve, a notched key, a nut on the screw-shank, gripjiing jaws, a spring catch. I'liny (died a. d. 79) reconnnends for auger- hamlles the wood of the wild olive, box, oak, elm, atul ash. He says nothing about the augers. Au'ger-mak'iug Ma-chine'. Augers are made by ditlcrent piucesses. They are cast ; swaged be- tween dies ; twisted as they pass through dies or by the successive motions of the parts of sectional dies ; or they are grasped by tongs aiul twisted by the hands of a skilled workman, and afterwards finished be- tween dies. One maker casts the screw-auger in a two-pait flask, the pattern of the central shaft and the seg- mental spirals being so divided as to pernut them to be diawn from the sand piecemeal. Many of the inventions in this line refer to dies of jteculiar form, and successions of dies of such form as to cause the blank to gradually assume the .shajie rei|uired. One has a pair of swaging dies, by which the twist is formed either by a succession of blows or by drawing through. The lips are made between dies of the required form, or aie bent down by an operation subsequent to the formation of the .spiral shank. Fig. 447 is a machine for turning the lips of augers. The sjiiral shank is clamped lietween the jaws with the lips projecting toward the wrench. The latter being advanced, the hub in its center embraces the center point and the lijis of the auger. The workman then seizes one of the handles of the wreuch-wlicel ami turns it towards himself, and while the auger is held straight by the engagement of its center point in the axis of tlie hub, the wrench bends the lips into the required ]»ositiun, the lips being turned simultaneously and their shoulders being left in the same line. Fig. 1 is a side eleva- tion ; Fig. 2 a hcnizontal section ; Fig. 3 is a face view of the wrench, and ¥ig. 4 is a view of the blank before the li|is are turned. In another maclune the revolving and longitu- dinally moving shaft has a transverse slot in its end. AUGER-MAKING MACHIKE. 189 AUGER, SQUARE-HOLE. Fig. 3 Fia.i in which the flat portion of the blank A (Fig. 449) is inserted, the sliaiik being held by a pair of tongs. Fig. 448. Machine foT making Augers. A series of dies, D (Fig. 448), arranged to clasp and hold the auger as fast as it is twisted, completes the process in one operation. The screw C on the shaft £ gives an intermittent longitudinal movement to advance the blank, which is twisted by the contin- uous rotary movement. A (Fig. 449) represents the blank, which is forged or swaged in a drop, and has a longitudinal rib or feather ninning along its center to insure the requisite stiffness and strength. The shaft B (Fig. 448) is provided with a cylin- der C, having a screw, or spiral groove, cut upon its surface, with a gaining twist. A pin secured to the frame under the cam works in the gi'ooves, serving as a nut. The shaft, being rotated by the crank or a pullfv, is drawn back as it tunis by means of the screw-cam. When half a turn is made, the first of the jaws D D are forced together by means of the cams on the shafts £. The first pair of jaws seize the auger, and, being the exact uega- Fig. 449. Aitger-tttisting Dies and Blank. tive of its twist, hold it finnly and prevent further twisting. The next pair come (o their work on the next lialf-turn, and so on until all the jaws have perfonued their office, when springs under the jaws force them simultaneously apart as the cams rotate past their centers. It will be seen, by reference to Fig. 449, that the faces of the jaws are dies, exactly corres]iondin,r; to the twist of the auger. Au'ger, Square-hole. An auger to cut square ItoIps was deseril.ied in the .Tournal of the Franklin Institute, Philadelphia, 1826, as the invention of Mr. A. Branch, of New York. It consisted of a twisted auger operating in a square socket which had a sharp lowej- edge, and which cut away the margin of the square hole as the auger itself bored a round hole in advance. H.wciil'k'.s Square-hole Borer (English) was in opjeration about the same time in London, and Fig. 450. operated in a substantially simi'ar manner, rt is a strong frame, fastened by screws b to the bench c ; d is an octagonal socket tapped to receive the ver- tical screw c ; to this screw is at- tached, by a cir- cular tenon and mortise, the square perforat- ing instrument /, wliich slides up and down through a rec- tangular hole in a brass guide g when the screw c is tunied by the cross-handle at top. The square incision is made by di- rect pressure downward, at the same tune that the center-bit m cuts out a round hole, the chips rising up and passing out at Hancock's Siiuart-hole Auger. AUGER-TWISTER. 190 AUTOGENEOUS SOLDERING. the two open sides of the square cutter, h is a jiiece of wood beiiif; boi'ed. The detaclied auger is shown on a larger scale ; the tenon ( is inserted in a cavity in tlie screw c, and made fast Ijy a cross-pin wliich goes througli botli. This arrangement allows a ready suljstitution of augers of dilferent sizes. The lower extremity of the revolving portion holds the center-bit m, whicli, owing to tlie collar n, cannot ascend or descend without the sijuare cutter which cuts out the angles beyond the range of tlie ciieular borer. The scpiare-cutting tool is a bar of steel with a round hole drilled out of the solid, and the edges are formed by tiling and giinding them to the bevels, shown in the enlarged figure. MEinurr's MueJiincfor boring Angular Holes, May 24, 1864. The holes' are bored by rotary cutters; fixed, anil reciprocating in a plane at right angles to tlie axis of the hole. The relatively lixed auger makes a round hole, as usual ; certain cutters which partake of the circular motion have also a recipro- cation towarils anil from their axis of rotation, being projected outward and again retracted four times in a rotation, to cut out the angles left by the round auger, thus making a square hole. See Bouing- MACHIXE. Au'ger-twist'er. A machine for giving the twist to blanks for screw-augers. There are many Fig. 451. Ait^er-Tivister. forms of machines for this purpose ; in one the blank is pressed between rolls u])ou a slide-rest, which are drawn together by a hand-screw. The blank is twisted simultaneously with the action of the rollers g g. The twist is regulated by the rate of longitudinal motion of the rest E upon the ways of the lathe, relatively to the rate of revolution of the front cen- ter «, which carries the blank. The degree of prox- imity of the rollers ;/ y twisting it round under ears on the side, or by means of a bail and screw, a gasket of linen being used. It is a form of Dr. I'apin's digester, and slioulil have a saCetv-vnlve. See DiOKSTlcli. Au-to-dy-nam'ic El'e-va-tor. One in which the weight of a falling cohiiun of water is made to elevate a smaller coluum to a higlit aliove the source ; and in which the changes of the x'ah'es are automatically produced. Such are water-rams, the fountain of Hero, etc. See WArEi;-ELE\'.\TOR. Au-to-ge'ne-ous Sol'der-ing. The junction by fusion of the joining edges of metals, without the intervention of solder. The edges, being brought together and brightened, are held under a jet of AUTOGRAPHIC INK. 191 AUTOMATON. burning gas urged by a blow-pipe, which melts the edges so that they run together. Au-to-graph'ic Ink. Ink suitable for transfer- ring to stone, writings or drawings executed in it upon prepared pajier. Trausfeniug ink. Dry soap 100 White wax 100 Mutton suet 30 Shellac 50 Mastic 50 Lampblack . . . . .30 melted, and worked into an ink. Au-to-graph'ic Pa'per. Paper prepared to re- ceive a drawing or writing in a suitable ink, and to part with the same to the surface of the lithographic stone or zinc plate, in the process of transferring. The paper is covered witli size, which resists the penetration of the ink into the paper. The drawing or writing is executed on the sized surface, so that when the paper is damped it may become detached from the ink, instead of carrying some of the ink away with it, as it would do if the ink were allowed to be partially absorbed by the paper. The size is made of Starch Gum-arabic Alum 120 40 21 This is spread on the paper, which is then dried and pressed. Or, for transfer of writing to stone, lay on the paper three successive coats of calves'-foot jelly, one layer of white starch, one layer of gamboge. Allow each to dry before applying the ne.xt. Smooth by passing through the lithographic press. Write on the gamboge surface. In transferring, damp the pa- per, place the ink-surface on the stone, and run it through, the press. The ink leaves the gamboge surface and adheres to the stone. A very fair transfer may be obtained from a good quality of writing paper. Au-to-graph'ic Press. A portable printing- press for taking impressions of autograph signatures from a litliograpliic stone, or form of type. Au-to-graph'ic Tel'e-graph. Invented by the Abbe L'aselli. An instrumejit fur transmitting auto- graphic communications, accomplished by the aid of two pendulums having a movement absolutely synchronous. One of the pendulums carries a pen or pencil of fine platinum wire, in connection with the line and the line battery, over the surface of the dispatch previously written in insulating ink upon a metallic paper. The other pendulum, at the corresponding station, carries an iron pencil, like- wise in connection with the line, over a paper pre- pared with a solution of the yellow cyanide of potas- sium. The electric circuits are so disposed, that when the platinum point in its pas.sage over the original writing touches the metallic surface of the paper, there is no emission of current along the line ; while, on the other hand, when the point touches the insulating ink, an emission of current takes place, and the iron point passing at the other end of the line over the prepared paper leaves on it a blue mark. The movement of the two pendulums being precisely equal, the reproduction of the dis- patch is absolutely exact. The same apparatus has been made to transmit por- traits executed in insulating ink upon metallic paper. Au-to-mat'io Fire. The automatic fire or ex- plosive mixture of the Greeks was made from equal parts of sulphur, saltpeter, aiid sulphide of antimony, finely pulverized and mixed into a paste, with equal parts of the juice of black sycamore and liquid asjihaltum, a little quick-lime being added. The rays of the sun would set it on tire. — Di;.\i'f;K. Au-to-mat'ic Lamp. A lamp used by dentists in the operatign of vulcanizing. When properly adjusted, the How of gas or alcohol is arrested by a spring cut-off, released by the breaking of a fusible alloy, and extinguishing the flame when the heat reaches a point slightly above that required to fin- ish the process of vulcanizing. Au-to-mat'ic Mal'let. A tool used by dentists in plugging teeth. There are several forms, but they agree in the delivery of a blow by pressure of the tool on the filling of the tooth cavity. See Dent.^l Hammer. Au-to-mat'ic Valve. A valve operated liy the fluid in jirogi'ess, in contradistinction to one operated by the positive action of a pai't of the machinery. Au-tom'a-ton. A machine whose motive- power is concealed within itself, or, as the term is more generally understood, a machine which im- itates the actions of men or animals, and, being moved by clock-work or other similar instrumental- ity, appecii's to perform certain acts by its own volition. Among the most remarkable of anticjuity were the automatons of Hero of Alexandria, who flourished about 217 B. c. They were made to move, as if alive, by machinery under the floor, and to utter sounds by the action of air dii\'en by water through small pipes, or by means of air raretied by heat. His works are extant in Greek, and have been frequently translated. Tliey contain many curious anticipations of modern devices, as well as many curious tricks and ettects no doubt intended as a part of the machinery of the priests to amuse the speculative and astound the ignorant. Archy- tis's flying dove was made about 4(iO D. r. Friar Bacon's sjjeaking head, 1264 A. D. An automatic coach, horses and passengers, was made by C'anins for Louis XIV. when a child. Vaucanson made an artificial duck which quacked, ate, and drank ; its food undergoing a change simulating digestion. V'aucanson also constructed a flute-playei', 1738. The writing automaton was a pantogra|ih, decep- tively worked by a confedeiate, 1769. The autom- aton chess - player was also a deception, 1769. Maelzel made a tnimpeter in 1809. An automaton speaking several sentences was exhibited in London about 1810. See Brewster's " Natural Magic." The speaking machine invented by a Viennese, exhibited in Europe many years since, and lately in this country, is not an automaton, but is jilayed by keys. The thorax is a bellows, and tlie sounds are made by the passage of air past reeds which simu- late the larynx, and modulated by artificial tongue, palate, teeth, and lips. The drawing automaton constructed by M- Droz, of the C'haux de Fronds, was a figure of a man 'the size of life, operated by clock-work anil s]irings, and capable of executing six ditl'errnt drawings. It used a metallic style, and drew on vellum. The transitions from one point to another were done by lifting the style, without slurring. It is fully described in Dr. Hutton's Mathematical Dictionary. M. Malliardet's writing automaton executed four pieces of writing in French and English. It was the figure of a boy resting upon one knee and draw- ing with a pen upon paper laid on a brass tablet. The wilting consisted in each case of several lines, and, after finishing each line, the figure returned to the beginning of the line to dot and cross the let- ters. 'The hand has two horizontal and one vertical motion ; the'down strokes of the pen were made relatively thicker by an increase of pressure. AUTOMATON BALANCE. 192 AWL. The aiiiifxed engiiwiiig is a lac-simile of a drawing executed by llie automaton of M. Droz. Fig. 453. Cktpid, Au-tom'a-ton Bal'ance. A machine for weigh- ing jilaiulu't or I'oiii, automatically sorting the pieces into /'«// and liijht weight, respectivfly. See CoiN-\vi-;ii:iiiN(; Machine. Au-tom'e-ter. An instrument to measure the quantity of niiiisture. Au'to-phoii. A barrel-organ, the tunes of which are produreil by means of perforated sheets of mill- boaril. Au'to-phyte Rib'bon. A Swiss ribbon printed by zinr [ilatis wliirli liave been produced by the photozuirii inocess from a real lace original. Au'to-type. A pliototypic process. The gel- atine is whipiH-d into a froth with warm water and sugar, skinnned, cooled, cut into blocks, and mixed with the pigments. To this creamy lluid the sen- sitizing agent, bichromate of potash, is added, and tlie liquid is cou\-eyed to a trough in a room with orange-colored curtains, where a traveling sheet of paper is covered on one side with the compound. The ti.ssue with its coat of sensitive varnish is then dried, and a j)ieee of the required size is exposed to the sun's rays in connection with a collodion nega- tive obtaim'd in the ordinar}4 manner. The requireil time having elapsed, the tissue is taken out of the case and plunged into cold water with its face downwards on a plate of glass, metal, or another paper, coated with a light solution of gelatine and clirome alum. Tlie surfaces having united, the whole is plunged in a bath of hot water, when the parts of the composition not hardened by the action of the light are dissolved, and the paper slips oH', the tougher parts remaining attached to the plate, and successive rinsings remove the cloud of colored gelatine until the picture is free. This is the Swan process of Carbon Printing (which see). Tlie next step is to prepare the "plate" for the printing-press. This consists of a mode of mount- ing the carbon-print upon a substratum of similar material backed by a glass or metallic plate, so that the picture may be used as a printing .surface. A mixture of gelatine, albumen, and bichromate of potash is mixed anil filtered. A sheet of plate-glass, about half an inch thick, is then leveled in a drying- box, warmed U)i to a temperatui'e of 100' Fahrenheit, and coated with the ])re)iaration. In about two hours the first coating is dry. The second coating consists of gelatine, albumen, and bichromates, with the addition of a .small quantity of an alcoholic .so- lution of resinous gums ; to this is added a soup^on of nitrate of silver with a few drops of a solution con- taining an alkaline iodide. After washing out the exce.ssof bichromate from the first coating, the second preparation is applied to the plate, which is iigain subjected to a high tenqierature in the drying-box, and becomes thoroughly dry and ready for use in two or three hours. The tough " negative " film is then laid down upon the plate-glass of the pressure-frame, and the plate, now conqdetely coated witli a sensi- tive surface, is laid upon it. The whole is exposed to the sunlight, and the progress of the in-intiugcau be easily ascertained by looking through the plate from the back. After exposure, the plates are well washed in cold water, rinsed thoroughly, and allowed to dry ; they are then ready for the ines-^. Subsequent operations depend u]ion two sim) le truths : first, that the gelatinous film will alksoili water ; and, .secondly, that any greasy mixture of the nature of printer's ink, or any pigment prepared in like fashion, abhoi-s the contact of water, and absolutely refuses to adhere to those portions of the plate which have absorbed tliat finiil. The success of the operation does not depend upon the relief of the ])late, but on the faculty of gela- tine for absorbing water, and then, as a niatter of course, resisting the impositicn of a fatty ink. See Hi;i.ioTVi'E. Au'to-ty-pog'ra-phy. Invented by George Wallis, London. By this method drawings are so executed that they can afterwards be impressed into soft-metal jilates. The drawings are executed preferalily on gelatine with a iieculiai' material whiidi is salient and makes a sunken impression in the plate against which it is driven by jiassing between a pair of rollers. The resulting plate is printed from as an orilinary eojqierplate. See also Molding fko.« rKUisii.Mii.i: () 11.1 Kris: N.\-rrnr.-iM;iNTiNG. Aux-il'ia-ry or Feed'ing En'gine. .Is fitted to sujiply tulailar boilers with feed-waler when the large engines are not working and the ordinary feed- pumps are tln-ivfore inactive. Aux-il'ia-ry Screw. A screw in a fully masti'd \essel ; used in calms, worT and head of the ferrule and finnly secured. In one form of pegging-awl the socket gripping the awl is surrounded by a sleeve, which is projected by a spiral iC= PfuJcins-y'rf'il'^ and Bodkin. from a needle in this, that one is attached to a han- dle and is retracted, while the other jKis-ses through the article and carries the thread which is attached to it. The sewing-machine needle, so called, is really an awl, except in that Fig. 454. small class where the needle and its at- tached thread are driv- en through the fabric, making a ninning stitch (Smith's, Dales's, and others). Inmany kinds of goods and materials it would seem so much better to have the awl provided with an eye near the end. that it is .singular it did not come into general use for sew- ing machines many yeai-s back. The idea was not new, for in the needles used in packing hampers [a. Fig. 454) the eye was placed near the point as in a bodkin, b, and the twine was pushed through be- tween the meshes of the lid and the basket, so that it could be grasped by the hand without push- ing the needle clear through. Tlie iipholstery nee- dle and thatching-needle are ancient and eye-pointed. The eye-pointed needle was one of the principal claims in the patent cjf Elias Howe, Jr., which netted him so large a fortune, and which, originally granted in 1846, was made by an extension to last to 1867. Awls vary in shape with the purposes for which the}' are intended. The round awl tapered to a point, a, is used for a marker or scratch-awl. The awl of a diamond shape, b, is used by har- ness-makers to form an opening for the needles which carry the threads. The round-shanked, bent- ended awl, c, is used by shoemakers to make a curved channel, which is followed by the bristle forming the point of the wax-end. The brad-awl, d, is used by carpenters to form an opening for brads, etc. It has a cylindrical shank, sharpened to a chisel-edge at the end. The awl c, used by wire- workers, is Fig. 455. ■^ 4' 7 * the leather. A convenient kit of small tools in- closed in a handle is shown in Fig. 458. The serrated shank of either tool is clasped in the gripper as the latter is screwed into the socket. A veceptacle p,gging-Awl. in the large end holds the tools. The awl-handle in Fig 459 is a locking pliers, whose jaws are adapted to hold either of the tools ; those not in use are inclosed in the hoi- ' Fig. 45S. low handle when the latter is closed. A boss on the end of the handle forms a ham- mer. The figure shows an elevation, open ; and a section, closed. In Fig. 460 the eye- pointed awl introduces the thread, which is fed from a sjiool concealed mthin the handle. Aicl and Tools. Fig. 459. Fig. 460 AlcUHandU. Lasting-Aict. Aids. Fig. 456. Stwing-AwL its shape renders it less liable to split the four edges wood. The sewing-awl (Fig. 456) is used by workei-s in leather. The pegging-awl is straight, and is strong enough 1.3 A^m'er. A machine for taking off the avels or o !(■/!« of barley. See Hummehng-m.\chin'e. ATwn'ing. A shield or shade for protection from the rays uf the sun ; usually attached to buildings, and especially to protect store-fronts and add to the comfort of pedestrians. The ordinary mode of sup- porting a roll of canva.s, by means of rafters resting against the building and upon posts at the curb, need hardly be described. The canvas is tacked to a roller and is furled by means of a running rope, being protected, when furled, by a pent-roof on the wall of the building. So far as ingenuity has been exercised upon thi.s square, and | subject it has generally been u]>on modes of lower- sharp on all I ing and winding, having especial reference to shad- ing sidewalks and show-windows. Some devices, however, have been intended for mndow-shades, and are modihed in shape and mode of operation to suit their location. Awnings of linen were first used bv the Romans AWNING. 194 AXE. Atoning. in the tlieiiter, wlieii Q. Catiilus tlcdicatod the Tenii)le of Jupiter, b. c. 69. After tliis, Lentulus Spinther is said to liave first introduced cotlun iiwn ings in the theater at tlie Aiiollinarian Games, July 6, IS. c. 63 ; they were reil, yellow, and iron-gray. By aud by, Cffisar the Dietator covered with awn- ings the whole Roman Forum, and the Sacred Way, from his own house to the ascent of the t'apitoline Hill ; tliis was 46 II. c, and is said to have appeared niorc^ wondeiful than tlic gladiatorial exhihition it.sdf Afterward, witlmut cxliihiting games, Mur- eellus, the son of (_)ctavia, sister of Augustus, when he was ajdile and his uncle consul the eleventh time, on the day liefore tlie Kalends of August, .fuly ai, 23 ii. c, pro- tected the Forum from the rays of the sun, that tlie people engaged in lawsuits nn'glit stand with less injury to tlu'ir health. Pliny says : " Wliat a change from the manners that prevailed under Cato the Censor, who thought that the Forum should even be strewed rfith I'altrops ! " The awnings e.Ktended, by the aid of ropes, over the amphithea- ter of tlie Enipei'or Nero, were dyed azure like the heavens, and liespangled with stars. The (itri- itm, or liall of audience, of the Koniaii houses, had an opening in tlie middle, which was covered in summer with a red awning. In Fig. 461 the awning is rolled upon a shaft having permanent liearings in the box which assumes an architectural form in the entab- lature of the slio])- Fig 402. jVont. The hem of the awning is fas- tened to a bar, which, when closed, forms the architrave, but which swings open when the awning is unfurled from the roller in the box, and is supjiorted by jointed extension- bars from the pilas- ters of the store- front. As the awn- ing unwinds, the hoisting-roiie coils on the roller, and becomes the means of refurling. In Fig. 462 the metallic plates which form the awning are arranged to lap one over another, each plate being fitted between guides, whicli are attached to the lower end of the plate im- mediately above it. The plates are connected to tog- gles, whiidi are operated by arms and a windlass, to raise and fold the plates, or to distend them into effective position. In the Louver awning each slat of the awning is pivoted in the rafter, and is connected by erank-arms to a bar which is operated by cords, so as to act, like a Venetian shtitter, upon all the slats simultaneously and exclude the direct rays of the sun, wdiile pennit- tiug a diH'used or reflected light to enter the store. In another fonn the light wooden slats of the awning fold over each other like the leaves of a fan. The slats are arranged on a suitable frame, and Fig. 463. Louver Atoning. there are two pulling cords, one of which spreads the awning and the other folds it up. Fig. 464. llJjULiyi-LLJ Metallic Atoning. Laztj- Tongs-E.rtension Atoning. In Fig. 464 the loweredge of theawning is attached to the boards, which are secured to the side extensors. The extensors are made in toggle-sections, operating as lazy tongs. The upper edge of the awning is coiled on a roller operated by a cord ; it is held by a pawl, to keep the canvas stretched. The spiral spring acts to keep the ann extended. Fig. 46.') shows front and tapered side-slats, which slide one beneath the other, beingconnected together by plates with headed studs, which work in slotted plates affixed on the adjacent slats. The end-slats collect like the folding parts of a fan ; the roof-slats take jiosition in vertical par- allel series when closed. Axe. A chopping and Fig. 466. Arched Atoning. felling tool. It has an eye by which it is attached to the helve. The edge is in the plane of the sweep of the tool ; it therein differs from the adze. riiiiy, who wrote about A. D. 50, felt bound to state an inventor for everytliing, and ascribed the invention of the axe to Divdalus, of Athens, about 1240 B.C. It is, however, to be supposed tliat AXE. 19i AXE. when Cecrops, three hundred years before, forsaking Egypt and leaving civilization behind him, hindcd in Greece, he had axes wherejvith to clear a spot for the village he founded. About the year 1093 B. c. we read that the He- bi'ews went to Philistia "to sharpen every man his axe " (1 Samuel xiii. 20) ; and about 89.3 B. r. " the axe-head fell into the water " while the man was chopping (2 Kings vi. 5). Previous to these two latter dates, and two hundred years before the time of Diedalus, we find that the Mosaic law, 1451 B. C, had anticipated the following sujiposed case : — "As when a man goeth into the wood with his neighbor to hew wood, and his liand feteheth a stroke \vith the a.\e to cut down the tree, and the head [Helirew. //■ a series of dies are arranged in the beii beneath and the recip- rocating block above. They cut off the blank for tlie axe-head, and shape and weld it while being held between the dies by means of a mandrel in the hands of the attendant. At the side of the machine is a punch for trinuning the eye and a trip-hammer with suitable dies for trimming the head. The axe under treatment is moved from one operative part of the machine to another, and swaged to fonn by suc- cessive blows. Fig. 476 represents a machine in which the axe is made by successive operations between dies. AXK. 19^ AXE. Fig. 476. Fig. 1 Itg.i Hutchins's Machine/or making Axes. In this illustration, Fig. 1 is a front elevation ; Fieri]ihery of the axle. In one form of diviiled axle the tongue is pivoted to the front siU-jiiece of the wagon-frame, coinci- dently with the pivot of the slotted middle section a y Divided Axle. A.\LE. I'J'J AXLE-BOX. Fig. 486. Drew^s Carriag€-Azle. of the axle-tree, and the tonc;ue is uot affected liy the contact of the front wheels witli obstructions in the road. The middle section of the axle-tree iornis a link in which slip the inner ends of the two outer sections, in which the axles of the wheels have their hearings. Kach wheel is secured to its portion of the axle, and each section of the axle-tree is secured hy ho\inds to its respective end of an equalizing liar, which oscillates on the tongue as the wheels swerve out of their course or change their parallelism with tlie Iiinil wheels. The tongue-hounds are hinged to their sections of the axle-tree, so as to allow tlie required vertical motion to the tongue, which has also a hingeiug joint. Fig. 487 shows a means of securing the wheel to the axle. It is intended for cliiliiren's cai'riages, and Deni>iOii^s Carriage-Axle. the fastening is jiot exposed at the outer end of the hub. A rod is fitted in the spindle of the axle, and provided at its outer end with a button eccentrically attached. The button in certain positions bears upon the outer end of the hub, and the inner end of tlie I'od is secured by a .staple and key. The bent or crank axle is much used in city drays, its purpose being to lower the bed without reducing the size of the wheels. Bringing the floor of the vehicle nearer to the ground ob\'iates lifting the load to any gi-eat extent. The bent axle, to enable the bed of the cart or wagon to come near to the gi'ouud, wliile letaining a large wheel, is a com- mon device in England in city and rural vehicles. One form of driving wdieel-axles for locomotives is also bent. Bai is an axle of a locomotive, in front of the driving axle or axles. The term is applied especially to the English engines, which are not sup- ported in front by a four-wheeled truck, as with us. A trailin(j-<\\\e is the last axle of the locomotive. In English engines it is under the foot-plate. A cnofi-axle is a driving-axle connected to the piston-rods of a locomotive whose cylinders are inside, technically speaking. Adriring-irlieel axle, or dririiiij-axlv, is the one on which the driving-wheels are keyed. The power is either apjilied to cranks on the axle, or to wrists on the driving-\vhi'(ds themselves. Ax'le-ad-just'er. A machine for trnring an axle by straightening out the bends ; or one for setting the spindle in proper line relatively to the axle-triH'. .See Axle-setting Machine. Ax'le-arm. The spindle on tlie end of an axle, on which the Ijox of the wheel slips. Ax'le-bar. An axle-tree with an arm at each en is placed perpendicularly between two rolls or beams, one of which canies the wai-p, and the other the finished carpet. Small tufts or bunches ot different colored worsted or woolen are tied to or fastened under the war]i ; and when one row of these tufts has been completed, a linen weft thread is thrown in and fimdy ranmied down. Another row of tufts is then knotted in, the selection of color.* being such as to cany on the ]iattern. To guide the weaver a-s to the position of the colors, a jiaper de- sign constantly hangs before him. The linen chain and weft are entirely concealed. Ayr Stone. A Scotch stone, called "Water of Ayr, " used as a whetstone and in surfacing metals ]ireviuiis to ]ioli.^lnng. Az'i-mutb Circle. The azimuth circle, as an astronomical instrument, is used for determining the azimuths of stars. The azimuth is an arc of the horizon intercepted between the meridian of the place of the oleervation and the vertical circle passing through the object. "^ Az'i-muth Compass. This compass isgiad- uated in degrees in.^teud of being divided by rhumbs, like the Mi(ri>ier's Compass. It has sights to allow the angles to be taken more accu- rately, and is designed to show the bearing of objects in respect to the magnetic meridian. By a comparison of the magnetic azimuth of a heavenly body with the true azimuth as found by calculation, the vanation of the needle is determined. The in.strument is shown in the accompanying fig- ure. The sight-plates ascend perpendicularly, and their slits are bisected by a pei-pendicular thread or wire, serving as sights. AZIMUTH ClKfLK. 204 AZOCUTK. Fig. ftlO. Fig. DU. Azimuth Compass. Tile ring of tlie gimbals rests with its pivots on tile semicircle beneath, the foot of which turns in asocket ; so that, while the box remains steady, the compass may be turned around so as to bring the sights into coincidence with the sun or other object observed. The pivots of the gimbals, in this as-in steer- ing-compasses, should lie in the same plane as the p(jint of suspension of the needle, so as to dim- inisli the irregular vibration as much as possible. In theinside of thccompass-bo.f linesaredrawu pei'iieudieularly down from the points where the sight-threads meet the sides of the box. These in- dii:ate the number of degrees, and parts of a degree, which the object bears from the magnetic north *or south, on which account tlie middli' of the a|iertures of the sight-vanes, the threads, and the above-men- tioned lines should be exactly in the same vertical plane at the time of reading otf the ob.servatioii. On one .side of the compass-box is usually a nut or stop, which, when inished in, arrests the vibratory motion of the card while the observer is noting the readiu'.;. Az'i-muth Cir'cle. The cut (Fig. .111) illus- trates an eipiatorial tlial, according to Dr. Hooker probably a JCmiifi-an'l, or azimuth circle, in the observatory at Benares, built by Jey-Sing, Rajah of Jayanagar, upwards of "JrtO years ago. Dr. Hooker describes the astronomer-royal at the time of his visit as a " pitiful object," half naked, with a large sore on his stomach, who represented himself as being very hungry. Science, it would seem, has not been properly appreciated in that vi- cinity since the decline of the Mohammedan jiower. See Dr. Hooker's Himalayan Journals, London, 18.55. The equinoctial and eipiatorial sun-dials of Be- nares are considered under Dial, where it will be seen that the former has a gnomon 30 feet long, and is ascended by steps ; each (|uadrant is nine feet long. The fact of the ascent by steps throws inter- esting light upon the passage in the Second Book of Kings, chap, xx., where tlie "dial of Ahaz" (742 B. c.) is referred to. White says that the Hebrew word signifies a staircase, and in this form doubtless were the dials of the Mesopotamian nations, and that seen at Damascus by Ahaz, and afterwards copied by Brass Azim)ilh. Benares. him in the one set up in .lernsalem. See A.stiuj- NOMICAI. In.sthUMKNts, where the large dial of Be- nares, referred to by Dr. Hooker, is sliowii on the eleA'ater tin- iiiule wlien it recedes from the creel and draws the yarn from the spools. Its jmtting, run- ning-in, or going-in, is the motion towards the creel when the winding takes place on the spindles of the mule. See Mui.E. Back'ing-up. 1. (Engraving.) Removing a hollow or mark from the face of a plate by blows from the peen of a hanmier applied to the back, the face being laid on an anvil or stake. This mode is used by engravers in obliterating lines too deep to be treated by the scraper or buriiLsher. 2. (Type.) The process of fortifying with type- metal the back of the thin electrotype plate which has been deijosited on the face of tlie mold obtained from the form of type. The back of the copper shell receives a thin coat- ing of tin, and is then placed face downward in a shallow iron dish in wliich it is secured by rods. The dish is then suspended from a crane and swung over a bath of molten metal. When it has acquired the tem- perature of the bath, a quantity of type-metal is dipped up and poured over the back of the copper plate, form- ing a solid backing. A planing-maehine reduces the backing to an even thickness, bringing the whole to a thickness of say one seventh of an inch. Back'ing-up Flange. (Muehincry.) A collar on a iiijie liy which the latter is held to Fig 513. its bearings or seat. Back-joint. Such a one as that fonned by a rabbet on the in- ner side of a chimney- jamb to receive a slip. Back -lash. The reaction or striking back of a piece of ma- chinery, wheel, piston, etc., when the power makes a temporary pause, or a change of motion occurs. It is a consequence of bad fitting or wear, and, in the latter case, indicates that the parts should be set up. The gib, cotter, and strap of the pitman connection are an instance of provision for said readjustment. In .some cases springs are arranged to keep the parts in positive contact, so that no reflex motion occurs, to be taken up suddenly when the power is again ajqilied. Back-link. (Stcum-Engine.) One of the links in a yiaiallel motion which connect the air-pump rod to the beam. Back-pup'pet. (Lathe.) The standard which holds the l)aik -center of a lathe on which one end of the work lests. See Lathe. Baok-pres'sure Valve. (Hydraulics.) A ball or clack-valve in a ^ipe, which instantly assumes '*' its place u]ion its seat when a refle.x or back pressure occurs. The figure with the arrow shows the normal condition ; the other fig- ure shows the valve on its seat. Back-rope. (Xauti- cat.) One of the ropes connecting the lower end of the the sbiii's bead. Back-sa'w. A saw whose web is stiffened by a metallic back of greater substance ; as, a tenon saw. Bacicing-up Flange. Bucfc- Pressure Valve, dolpliin-striker with BACK-SIGHT. 207 BAG AXD srooy. Back-sight. 1. (Fire-arms.) The war sight of a gun. It may be of various forms. In the okl- fashioned arms intended for round balls, it was merely a notch in a knob or plate near the breech of the gun, the proper elevation to be given being estimated by the marksman. As the eti'eetive range scarcely exceeded 250 to 300 yards, this could be done with sufficient accuracy by an expert marks- man ; but with the introduction of the elongated bullet, giving ranges of 1,000 yards and upward, it became necessary to seek some more efficient means of securing the proper range at these long distances, so that the bullet might not either pass over or fall short of the object. For this purpose was introduced Fig. 515 Back-Siglits. the rear-sight (a, Fig. 515), consisting of an upright slotted branch, which was jointed to a seat on the barrel of the gun, or, in some instances, on the small of the stock in reir of the barrel. A notched slider on the upright branch could be elevated as desired, and by elevating the muzzle of the gun until this notch and the front-sight were in line, any range within the limit of projection of the piece could be attained. This sliding sight has, in the United States ser- vice, been superseded by the leaf-sight (f>. Fig. 515), which is more compact and less liable to derange- ment. Also called Folding-Sight. Other back-sights, especially those fir.st introduced in Southern Germany, have been made very differ- ent in form from those described ; one variety (c. Fig. 515) being permanently fixed perpendicularly to the barrel, and ha'ving notched holes at proper bights through which to sight, and another (rf. Fig. 515) being segmental in shape, and moving circularly in a direction longitudinal to the barrel through a stud fixed thereon. .\nother form of back-sight (e. Fig. 515) vertically adjustable for range, and attached to the stock, has a graduated spring-piece slipping within a vertical slot in the small of the stock, and is adjusted as re- quired. Its spring retains it in jilace, or it may be clamped by a set-screw or lowered below the line of the hind-sight on the barrel. 2. (Lereliiig.) The reading of the leveling-staff ; taken back to a station which has been passed. Read- ings on the forward staff' are /ore-sights. Back-staff. (Opfies.) A peculiar sea-quadrant, invented by Cjiptain DaWs, 1590. It has a graduated arc of 90° united to a center by two radii, with a sec- ond arc of smaller radius, but measuring 6° on the .side of it. To the first arc a vane is attached for sight ; to the second, one for shade ; at the vertex the liori- zontal vane has a slit in it. The back of the ob- server is turned towards the sun at the time of obser- vation. (Admiral Smiith.) It is now superseded by instraments of more mod- ern type, such as the reflecting quadrant and sextant. Back-stay. (Shipbuilding.) One of the guy- ropes, just abaft the shrouds, extending from all topmast-heads to the sides of the ship, to stay the masts. They are attached to back-atatj stools, which are detached channels or chain-wales. Back-strap. (Saddlery.) The strap passing along the back of the horse. In wagon harness it extends from the upper luime- slrap to the crupper ; or, in the absence of a crupper, to a point of junction with the hip-straps. In carriage harness it extends from the gig-saddle to the ernpper. Back-sw^ord. A sword with one sharp edge, in contradistinction to one which has two edges through- out the whole or a portion of its length. Back-tool. (Bookbinding.) A fillet, roller, or other hand- Fig. 516. tool for dry-tooling or gilding the backs of books. Back'w^a-ter. (Hydraulic Engineering.) Water reserved at high tide for scouring a channel or harbor by discharge at low-tide. See Flfshixg. Bad'ger Plane. (.loin ing. ) A panel plane whose mouth is cut on the skew, and from side to side, so as to work up close to a corner in making a rabbet or sink'ing. Ba-dig'eon. A cement for stopping holes and covering defects in work. Statuary's: plaster and free- stone. Joiner's : sawdust and glue ; whiring and glue ; putty. Cooper's : tallow and chalk. Bach-Tool. Stone - mason's : wood - dust and lime slaked together, with stone-powder or si- enna for color, and mixed with alum-water to the consistence of paint. Ba'e-tas. (Fabric.) A plain unchecked woolen stuff', manufactured in S]>ain and Portugal. Baft, Baft'as, Baf' fe-tas. (Fabric.) a. A blue or white cotton goods, used in the African trade. h. A kind of East Indian cotton piece-goods. Bag and Spoon. (Hydraulic Engineering.) An imidement used in dredging for river sand. Fig. 517 i 'I It is a hoop of iron with a steel lip, and has one edge pierced with holes, for the attachment of a leather bag by lacing. The spoon is suspended by a chain, and has a long handle by which it is guided. BAGASSE DRYEB. 208 BAGASSE FURNACE. Being sunk in position, it is diawn along the bot- tom, hoisted hy a crane, and dumped into a lighter or mud barge. The Iwg i.s perforated for the eseape of water. The rut shows the bag overboaid, and j about to \v sunk to the bottom by means of the j pole. Ba-gasse' Dry'er. Bagasse is crushed cane as it comes from the mill, deprived, to a great extent, of its juice and saccharine matter ; also of the leaves, which are stripped from it previous to grinding. According to Wray, good mills only extract from 70 to 75 per cent of the saccharine matter which analy- sis shows to be present in the cane, and the remain- der, after the water is evaporated, joins with the liber and other carbonaceous matters to form a fuel, coal and wood being very expensive In sugar-cane regions. The bagasse is sometimes carted to the field, to be dried by the sun, but a number of United States patents have been granted for apparatus for drying it by artifii'ial lieat. Other furnaces are constructed merely for burning it to get rid of it. Vast piles of it accumulate round the niill-liouses. In Mehuick's jiatent of April 10, 1815, the ba- gasse is transferred to an inclined chute, whence it is taken by an endless apron, which passes around reels or drums, and conducts it through a series of three heati'd compartments, linally depositing it on a plate or platform in front of the furnace, or other convenient position. Another form of the Bagasse Dryer consists of an inclined o]ien-euded cylinder, having a steam jacket and hollow bolts, through which escapes the water evaporated from the cane. The steam is introduced through hollow trunnions, and the dryer-tube is ro- tated by pinion and annular gear, as shown in the figure. The material is fed in at the upper end, and works gradually to the lower end, where it forms a Fig. 518. Bagasse Dryer, pile of ary stutf, and is forked into the furnace be- neath the sugar-pans and the engine which runs the establishment. Ba-gasse' Fur'nace. A furnace for consuming the bagasse (or megass), the cane remaining after the pressure of the saccharine juice therefrom. It gen- erally consists of a kiln or large chamber with a flue to the furnace-space beneath the boilers which make steam for the cane-mill. The principal reason for burning it is to get rid of it, as it accumulates around the sugar-house and JUL Fig. 519. of the bagasse and fuel thence passes beneath the boilers which drive the sugar-mill, and, in some sugar- Fig. 520. Bagasse Furnace. becomes quite a nuisance. By dint of making a roaring fire, it may be consumed, and perhaps add something moie to the fire than it subtracts by the evaporation of its water. The example (Fig. 519) shows it as dumped in a pile upon the grating above the fire. The lieat resulting from the combustion Bagasse Furnace. houses, heat the vacuum-pans, defecatore, surface- evaporators, and run the pumping-engiiies. BAG-CLASP. 209 BAGGAGE-CHECK. Fig. 520 shows a fumace for burning the cane- refuse, and the relation of the fiiriiaoe proper a to tlie discharge-apron b of the cane-niill, the feeding devices c c and the furnace d, of the steam-hoilers. The bagasse does not pass beneath tlie boilers, but the flame of the fumace a is carried into b through the flue e, and additional air is admitted beneath the grating of d by dampers in the ash-jiit. Bag-clasp. A clamp or cincture for closing the mouths of bags. See B.^g-fastener. Bag-fast'en-er. A device for clamping or tying the mouths of bags below the hem. A substitute for a bag-string. A number of different modes are shown in the illustration, and will be briefly described. Fig. 521. Saf, Fasteners. a. A sheet-metal ta/;, with a curved taperirg slot, is permanently attarh?d to one end of the string. The other end of the string becomes jammed in tin- slit. b. The metallic t-ig attached to one end of the string has a thimble in which the othe'. end of the string is jammed by a wedge. c. Cue end of the string has a permanent ring. The other end is rove through an ey.det in itse'.f, and jams against the ring. d. One loop is ])ernianently attached *.o a .slotte 1 lever. The latter is rove through the other loop and turned over beyond the dead-C'?nter, fM as to jam the loop against the standing part. e. The standing end is rove through two holes in the tag, and fonns a loop which jams down upon the point end of the cord. /. The point end is jammed between two pivoted, cogged sectors. g. The perforated leather tag is riveted to the bag, and the thong is rove through the holes so as to bind tightly. A. One end of the cord is knotted to the loop of the wire. The other end is passed round the bag tud jammed between the jaws. i. A pair of hinged clasps whose free ends interlock. j. A spring de\nce, acting in the manner of a brooch ; a spring pin engaging a catch. k. A lever attached to one end of the cord engages > loop on the other end, and is thrown over to cany Ihe loop to a curved iX)rtion, which holds it securely. 7. Similar to the last, but haviug a means of ad- justment. U A device some- Fig. 522. Bag-fil'ter. {Sugnr-Bejinhig.) times used in clearing saccha- rine solutions of feculencies and impurities mechanically suspended therein. In one form the juice is al- lowed to pass through a series of copper-wire sieves of grad- ually increasing fineness be- fore reaching the flannel bag; perhaps the more usual fonn is that in which the sieves are replaced by the series of ver- tical flannel strainers arranged in a lower chamber, having a stopcock, into which the juice is admitted from a com- partment above. The example consists of a sirup-cistern S, in whose floor are short pipes of conical fonn, to which flannel biigs / are tied. The juice, passing down each of the Jiipes, distends the bags, and drips down their outer surfaces, collecting in the chamber below, whence it is drawn by a faucet. Bag-frame. The metallic frame to which the leather or cloth part of a cai7>et-bag or valise is secured, serving to imjiart stili'ness and aflbrd nieaus of attachment for the handle and lock. Fig. 523- Bag- Frame. Eag'gage-check. A tag or label to he attached to a trunk, to indicate its destination ; usually, also, its [loint of departure, and frecjuently the name of the railway company attaching the said check. The devices are numerous. « (Fig. 524) shows a check or label-holder of two metallic portions which form a frame for the inclosed card, on which is inscribed the name of the place of destination. This is used also for niail-b:igs. 6 is a lock-up case for a number of such cards, either of which is exposed at the opening as may be reipiired. c has two series of ntmibers on wheels, and the places of departure and destination are indicated by nmnbers agreeing with the schedule of stations. d has the places of departure and destination on the respective sides. Either of the readings may be hidden by the strap which is rove through the loop at the other end from that of its attachment to the check. On the return trip, the other side of the check is exposed by the inverse reeving of the strap. e has a disk with a circumferentially numbered margin. A number agi'eeing with the schedule-num- ber of the station for which the baggage is bound is exposed at the opening in the plate. By an arrange- ment of the strap, the latter is made to hold the BAGGALA. 210 BAG-MACHINE. ilisk, so as JiKiire. to secure the required presentation of Fig. 624. VjS^y Ji-fnk I o Baggage- Checks, f has the series of station-numbers in a row ; the strap is so rove tlirough the slots as to indicate the station (29) at wliich tlie baggage is to be put off. f/ is a metallic case inclosing a card with the num- bers of the stations printed thereon. A punch-mark indicates the station of destination (14 in the il- lustration). The strap holds the parts of the case together, being rove through the loops. A has a dial-plate and pointers, which indicate the station of departure and destination. i is a metallic disk with radial slots and corre- sponding nnmbers. The strap is so rove through the slots as to give the required indication. Bag'ga-la. {Nautical.') A two-masted Arabian vessel, frequenting the Indian Ocean. A dhow. The capacity is I'rom 200 to 250 tons. Bag'ging. (Fabric.) 1. A coarse fabric made of old ropes, hemp, etc., for covering cotton-bales. 2. The gunny-cloth of India is made from jute. In Bengal, from one or two species of Corchoms ; in Bomliay and Madras, from the Crotalaria juncca. Bag-hold'er. A contrivance to hold up a bag with the mouth open ready for filling. There are many I'orms, — some adapted for large gi'ain-bags, others of a smaller size for Hour, seeds ; still smaller, for ordinary groceries and counter use. a has a platform on which the sack stands, and its weight spreads the horns within anil distends the mouth of the sack. b has a liolder adjustable as to hight, and a hop- per to whicli the mouth of the bag is attaclied. c has clasjiiug bars operated by a foot-trigger. Fig. 525. Bag-HoVler. Bag-lock. a. A peculiar form of lock, used for satchels, etc., frequently merely a ]iadlock. There are many varieties, — snap-latches, clasps, thumb and key bolts, etc. In the illustration are shown se\-eral varieties, which do not require explicit description. Fig. 526. /(QBHi^|g')( Bag Locks. b. A lock for mail-bags, usually some form of pad- lock, seal-lock, or shackle. Bag-ma-chine'. .\ machine for making bags of ]iapei or textile fabric. The term is usually ap- plied to machines which make jiaper-bags for sales- men's and domestic uses. In some of these the pa]ier is handled as in an envelope-machine, blanks of a certain size and shape being pi'cviously cut out ; these are fed one at a time to the machine, either automatically or by hand, and are gummed, folded, and delivered in a pile. In other machines, the pa- per is made u]> into a liollow tube, like a stove-pipe, and is fed to the machine which makes an oblii|ue cut, forming a flap which doubles over to close the bottom of the bag at a subsequent operation. See P.\PER-E.\G M.\CHINE. Looms are constructed specially for making seam- less bags, having a circular sJicd for that purpose. After making the length of two bags, the sheds are united, so that the tubular portion is closed and a single web of double thickness is formed. A coujde of inches of this is enough, and by a transverse mid- way cut this double portion, thus divided, forms the BAG-NET. 211 BAIL-SCOOP. closure of two bag-bottoms. The double bag-length of the tubular portion is also transversely divided midway, the cut forming the mouths of two bags. Bag-net. (Fishinij.) A landing-net, or net bag- shapid, for sweeping a stream, or to be set in a stivam to ct. .ch fish. Bag'nette. {.Architecture.) A small molding, like the astragal. When enriched with foliage, it is called a ckaphJ : when plain, a hmd. Bag'pipes. An ancient Greek and Roman in- strument. The leathern bag receives air through a valveJ tube from the lungs orabellows, andis squeezed by the arm to drive the air into the pipes, which are operated by the performer. The ba.ss pipe is called the drone, and the tenor or treble pipe the chanter. It is now considered a Scotch or Irish musical in- strument, though Xero is reported to have solaced his gentle mind with its strains. Foi-merly common throughout Europe, it is now nearly restricted to Scotland, Ireland, parts of France, and Sicily. It is the common country instrument of the Pun- jaub. The Sikh instrument rather resembles the Italian pfiferari than the pipes of the Scottish High- lander. " After dinner we had a fellow play well upon the bagjiipes, and whistle like a bird exceeding well." — Pepijss Diary, May, 1661. Its notes are remarkable for power rather than sweetness, and reipiire uncommon skill in the per- former to render them even moderately pleasing to a cultivated ear, unless from the force of habit or the associations connected with the instrument. De guitibiis lion est dispuiandmn, — the Komans flaTored their sausages with asafetida. Pipers are still attached to the Highland regiments in the Biitish service. The antifpiarian notices of the instrument are in the Mitsurgia of Luscinius, 1536, and in " Don Quixote." Fig. 527. Baspipes. The Irish bagpipe was originally the same as the Scotch, but they now differ in having the mouth- piece supplied by the bellows A, which, being filled by the motion of the piper's arm, to which it is fas- tened, fills the bag £ : whence, by the pressure of the other arm, the wind is conveyed into the chanter C, which is played on by the fingers like the com- mon pipe. By means of a tube the wind is conveyed into drones a a a, which, being tuned at octaves to each other, produce a kind of cronan or bass to the chanter. The lower cut represents the improved or union pipes, the drones of which, tuned at thirds and fifths by the regulator, have keys attached to theiu so as to produce chords, parts of tunes, or whole tunes, even without using the chanter. Both drones and chanter may be rendered quiescent by stop.s. Bag-pump. (Hydraulics.) A form of bellows- pump iu which the valved disk a, which takes the place of the bucket, is connected with the base of the barrel by an elastic bag distended at intervals by rings. It is described by Dr. Piobinson in his " Jlechanical Pliilosophy." It is much older, however, than this work, and has been invented again and again, from time to time. Bag-reef. (Xautical.) The lowest reef of a sail. Bags. (Porcelain.) The flues in a porcelain oven which ascend on the internal sides and enter the oven at elevated points, so as to heat the upper part. See OVE.S. Bag-tie. See B.\G-F.4.STE>rEE. Bag-weigh'er. A form of steelyard adapted for this pur- pose. See STF.ELV.iRD. Bail The arched handle of Ba?-Pu7np. a kettle or bucket, to which it is usually connected by loops called ears, on the latter. The ends are usually bent around the ears, so as to be permanent, though loosely attached ; but sometimes the hail is jointed, and adapted to be hooked to the ears as oc- casion may require. The bails of common wooden buckets, such as are used in the house or sugar-camp, have their hooked ends inserted into perforated metallic plates, or cars, which are tacked to the staves. The crane-ladle of the foundry has a bail; the smaller ladles have cnitched handles. Bails. (Xautical.) The frames that support the awning or tilt of a boat. Eajl-scoop. A scoop or pivoted trough, designed for draining bofiies of water. That shown in the cut was contrived by llr. W. Fairbaim, and is adapted to be worked by the single- acting Cornish engine. The scoop S turns on a center at C ; its other end is connected at E to the end of the engine-bKim B, supported on a suitable foundation /'. Z> is the drain, and X the level of the water in the river or place of discharge. The stroke of the engine raises a weight suspended from the beam and depresses the end JR of the scoop, into which water is admitted through the upwardly opening valves F. The weight then descends by its own graWty, elevating the im- mersed end of the scoop sufficiently to discharge its contents into the water at L. The dip may be regu- lated by shifting the connecting-rods. The scoop is made of boiler plate-iron, and is 25 feet long and 30 wide, with two partitions across it to strengthen the sides and afford bearings for the valves. Seventeen tons of water can be raised at each stroke b}- this machine, and with an engine of 60-horse power it will do a duty equal to three pounds of coal per horse-power an hour. BAIT-MILL. •212 BALANCE. Fig. 529. Fatrbnim''s Batl-Scoop. Bait-miU. A machine used by the " Bank " fi.shiTiii '11 lor cutting lish into bait. It is an oblong woolIl-u hoK, staniliiig on one end, and contains a roller armed with knives, and turned by a crank on the outside. It reseihbles in form and operation a saiisage-cnt- tini,' nriehine, but delivers a coarser ])roduct. Baize. {Fulirii?.) A coarse woolen fabric with a long uaj), principally used for covering tables, screens, etc. First made at Colchester, England, in 16(i0. " Bought me a new black baize waistecoate, lined with silk." — Pcpi/s, 1663. "Sir Thomas Clilibrd talked much of the plain habits of the Spaniards : how the king and lords themselves wear but a cloak of Colchester bayze, and the ladies mantles, in cold weather, of wliite ll.uincU ; and that the endeavours frequently of set- ting up the manufactory of making these stnlfs there, have only been prevented by the Inquisition." — Ibid., February, 1667. Ba-la-lai'ka. {.Vusk.) A musical instrument of tie- lundour kind, of very ancient Sclavonian origin. It is in common u.se both with the Russians and Tartars, According to Niebuhr, it is also frequent in Egypt and Arabia. The body of it is an oblong semicircle, about si.v inches in length, with a neck or finger-board of two feet. It is played on with the tin;.;ers, like the bandour or guitar, but has only two wires, one of which gives a monotonous bass, and by the otlier the air is produced. Bal'ance. The word balance is applied to many things : .so:ne in rel'erence to their resemblance to the oscillating beam of the scales, such as the bal- ance-beam or xcorkimj-beam of some forms of steam- engines; the balance-handle of a table-knife, which is weigliteil to lift the blade from the table-elotli ; the ba'ancc-beam of a crane whose jib is poised on the post ; the balance, or pivoted beam of one form of electrometer ; the bn'ance-tlwrmometcr, which is poised on a stem, and is thrown out of e(]uipoise by fluctuations in the length of the column of contained mercury. The balance-coclc of a watch affords a bearing for th.' u]i])er pivot of a watch-balance. The balance-plale and balance-ring are parts for sustaining the upper ])ivot of a watch-balance. They diir-r in sliape, but that is their function. The balance-sprinr/ is the hair-spring which gives the recoil motion to the oscillating bahince-u-hcel, whose pulsations determine the rate of movement of the timekeeper. The balance-verge is the arbor of the balance, and carries the pallets which act upon the scape-wheel The balancc-iccight is a shifting weight to poise the balance, or a counterweight to balance the weight of other attached parts, as in the driving-wheel of a locomotive, etc. ; or a weight to partially coun- terlialance the weight of a valve, and enable it to !"■ lifted more readily. The electric balance is a form of electrometer. The hi/tironielric balance is a form of hygrome- ter, in which the absorption of moisture destroys the eipiipoise of a Ijalanced beam. The Injdrostatic balance is a modification of the ordinary balance, for the purpose of obtaining specific gravities. The steam -balance is the ordinary safety-valve which has a weighted lever. It was invented by the illustrious Dr. Papin, of Blois. The torsion-balance is a delicate electrometer, in which a horizontal bar is suspended from a wire which is twisted by the magnetic attraction or re[iulsion. The specific-gravity balance was due to the dis- covery of Archimedes. The •■ Book of the Balance of AVisdom," by Al- Khazini, of the twelfth century, is a treatise on the specific-gravity balance, which he credits to Archi- medes, narrating the story of Hiero and the Syra- cusan goldsmith ; and which, as he says, " is founded upon geometrical demonstrations, and deduced from physical causes, in two points of view ; 1. As it im- jilies centers of gravity, which constitute the most noble and elevated ilepartuient of the e.xaet sciences, namely, the knowledge that the weights of hea\y bodies vary in proportion to the difi'erences in ilis- tance from a ])oint in common, — the foundation of the steelyard ; 2. As it implies a knowledge that the weights of heavy bodies vary according to dill'eience in rarity or density of the liquids in which the Ijody weighed is immersed, — the foundation of the balance of wisdom." The book of the Saracenic philoso|iher was translated by Chev. Khanikolf, Russian Consul- General at Tabriz, Persia ; and an English transla- tion is in the sixth volume of the "Journal of the American Oriental Society," New Haven, 1860. In connection with the subject of the great relative weight and accepted theory of the value and purity of gold, the pious Moslem enters the following pro- test : — "When the conunon people hear from natural philosophers that gold is the most equal of bodies, and the ore which has attained to perfection of ma- turity at the goal of completeness, in respect to eciuilibriuni [stability of character, under circum- stances wdiich dissolve or destroy other metals], they firmly believe that it has gradually come to tliat per- fection by passing through the forms of all [othei] bodies, so that its gold nature was originally lead, afterwards became tin, then brass, then silver, and finally reached the perfection of gold ; not knowing that the natural philosophers mean, in saying so, only something like what they mean when they speak of man, and attribute to him a completeness and an equilibrium in nature and constitution, — not that man was once a bull and was changed into an ass, and afterwards into a horse, and after that into an ape, and finally became man." This has been wrongly quoted ; it is not fair to call Al-Khazini a Darwinian. The balance of Archimedes was a beam, with bowds suspended from fixed points at each end, and a mov- able weight adjustable on one arm of the beam, which was graduated from the fulcrum to the point of sus- pension of one of the bonds. By adjustment on the arm, the weight was made a counterpoise equal to the ditiereuce between the weights in the respective bowds. The balance of Mohammed Bin Zakaziya differed from that of Archimedes by the introduction of the BALANCE. 213 BALANCE. indicator-needle attached to the beam, and called by the Ai-abs the toii'jao, and by the substitution of a morable suspended scale for the movable weight to balance the difference between scales. Both were described and exhibited by Al-Khazini in his work above referred to. 1. The original form of weighing scales was prob- ably a bar suspended by the middle, and with a board or shell suspended from each end, one to con- tain the weight, and the other the matter to be weighed. Paits of the original picture (Fig. 530) Fig. 530. Egypt an Scalfs. are defaced by time, as indicated. An ancient Eg\p- tiin balance, consisting of a wood>^n beam and a piece of lead at the end for a weight, was found at Sakkarah. In early times, before the coinage of money, the precious metals were weighed out, and the duty of weighing was regulated by the municipality, antl attended to by public weighers, as we see in the Egyptian monuments and read in classic literature. Abraham paid for the land he bought in silver, wei'fhmg it out to Ephron, 400 shekels of silver. The soni of Jacob also paid for the wheat they bought in Egypt at a given price in metal, weighed out to the officers of Joseph. For the early uses and gradual improvement in th^ production of coin, see Coin'AGE. The " balance " of the Bible was similar to that of Egvpt, the ends of equal length, and the beam suspended by its mid-length. The frequent refer- ence to false and unequal balance shows that the lever-balance on the "steelyard" principle was un- known to them. The lever of unequal lengths on each side of its point of susfiension affords a convenient mode of iletermining weights of various objects with but a single weight, the object being suspended from the end of the shorter arm, while the bob is shifted along the graduated longer arm until it forms an e.Kact counterpoise for the object weighed. Tliis is c lUed the s'teh/nrd, probably from its material and former length in Englaml, and is also known as the Homan Balance {Stntcra). See Steelyard. Balances for delicate operations, such as those used iu a-ssaving and chemical manipulation, are made with extreme care. The beam should be as light as possible consistent with inflexibility : for not onlv the inertia, but also the friction, is increased in pro- portion to the weight, and the sensibility consequently diminished. A cylinder of steel passing at right an- gles through the center of the beam fonns the axis ; and its extremiries, ground into sharp edges on the lower side, serve as the points of support. The two edges must be accurately in the same straight line, and turn on smooth planes of agate or polished steel, carefully leveled. The pans should likewise be sus- pended from the extremities of the beam by agate planes resting on knife-edges. A needle or tongue is usually attached to the beam, pointing directly upward or downward, when the beam is hoiizontal, fen- the purjjose of indicatii.g the delations of the beam from the horizontal [o^i- tion, on a giaduated scale. It is better, however, to bring the arms to temii- nate in points, and to jilace a divided scale behind each. In this way the slightest deviation of the beam will be rendered e\ident, if the zeros of the scales be placed exactly in the same level. The scale is indispensable, because the balance, if veiy sensitive, would require a long rime to come to jest ; r/ c^S ^^^ ^^ ^* known to be poised ^(/ ^■, C^ when the excursions of the ^' 2i^ needle on both sides of the 3^ zero of the scale are equal. \ In order to preserve the knife-edges, the beam, when not in use, is supported on rests. Props should also be placed under the pans when loading or unloading the balance. The whole apparatus must be placed under a glass case, to pro- tect it from the disturbing influences of currents of air. The sensitiveness of a balance constructed with due care may be carried to almost inconceivable extent. Analytical balances are usually made to carry 1,000 grains in each pan, and to turn with the -^g^ part of a giain. There are several large balances in use in the Eng- lish mint, calculated to weigh from 1,000 to 5,000 ounces Troy. Some of them t\irn with -j's of a grain, when loaded with 1,000 ounces in each scale, or with j oootijo part of the weight. Fig. 531. 5=3 Coin Balance. To the mode of suspending the beam and the scales BALANCE. n4 BALANCE-BOB. more attention has probaUy been directed than to any otliLM' part of tlie balance. 01' some of the European balances, — Fox's beam has pivots, the conical ends of wliich play in hollow agate cones of larger angle. Of.utlino's beam is coated with plutinmn or pal- ladium, tlie knife-edges and planes being of agate, and the instrument proof against acid fumes. The knife-edges are let into dovetailed notches in tlie beam. Tlie beam is graduated, so that .small differ- ences of weight can be determined by placing a small platinum wire weight on one of the divisions of the graduated beam. Stkinueil suspends the beam by wires or silk cords. In another of Steinheil's, the beam carries two small steel spheres in the middle, resting on a steel plane, and a sphere at either end, upon which rest tlie plane or slightly convex spheiical surfaces of the plates, from which the pans are suspended. Among the modes of delicately adjusting the parts to obtain perfect ei|uiUbrium may be cited : — In DoVEii'.s the tinal adjustments in the direction of the length of the beam, and in a direction perpen- dicular to it, are affected by a cut at each end of the beam, making an angle of 45° with the axis of the beam, and capable of being widened by a screw. In the American balance the socket in which one of the extreme knife-edges is fixed moves in a slit in the direction of the lengtli of the beam, and is ad- justed liy means of two screws. In OKiiTLiNfi's the adjustment of the distance of the extreme knife-edge from the middle knife-edge is effected liy a vertical cut in the metal of the beam, capable of being slightly widened or contracted by screws. Among the modes of checking the oscillation of the pans may l)e msntioned Dolberg's, which con- sists of hair-brushes turning on a handle, and as- cending till tlie ends of tlie brashes touch the under side of the pan. Tlie mode of obtaining quiescence of the pan in the periodical intermittence of the coin-weighing apparatus is by a depressed ivory point above and an agate point beneath. In Fox's balance the beam is brought to zero by the attraction of a magnet. The sensitiveness of a balance depends (after fric- tion has been reduced to a minimum), first, on the proximity of the center of gravity to the point of suspension on which the beam swings ; and the cen- ter of gravity must be directly below the point of suspension. Secondly, on the f:ict that all three knife-edges are in the same plane, to prevent the farther lowering of the center of gravity when the beam is loaded. Tliirdly, on the rigidity of the beam, to prevent a similar lowering by springing. See Faraday's "Chemical Manipulations" for sug- gestions in construction and management of delicate balances used in quantitative analysis. See also CoiN-WEiGHiNO Machi.n'E ; Counter Sc.\LES; MlciiOMETEiiB.\L.\.\CE ; Pi,.\tformSc.\les ; Si'iiiNG B.\L.\NOE ; Steelyard ; Weighing Ma- chine. Fig. 532. ed of two weighted arms, oscillating on a vertical axis. The clock of Henry de Wick, made in 1379 for Charles V., had a balance of this description. The balance, so far as watches are concerned, is a wheel driven in one direction by the mainspring acting through the train of gearing, and returned by the force of the hair-spring. While watches of the va- rious kinds have balances, their escapements gener- ally constitute their distinguishing features by which they are named and known. See Escapement. In regulating a watch, the length of the beat of the balance is increased or shortened to make the watch go slower or faster. This is done by letting out or taking up the hair-spring. See H.\IK-SPIIING : CoMPENs.vrioN Balance. The clock or watch balance consists of — The rim. Verge ; spindle or arbor. Spring ; which gives the recoil movement. Segulator ; determines the length of spring in- volved in the movement. Cock : att'ords a bearing for the upper pivot. Potancc ; a step for the lower pivot. Pallets : the plates on the verge, which engage the scape-ichccl. 3. (Elcclricity.) A tenn applied to a device for measuring the resistance of an element of an electric circuit. Also known as a Bridge. Bal'ance, Al-loy'. Robert's Alloy Balance is intended for weighing those metals whose ]n'opor- tions are stated decimally, being constructed on the principle that weights in cquilibrio are inversely as their distances from their points of support. The point of suspension, «, of the balance is ad- justed until the arms are respectively as the two stated proportions, — say 17 tin to S3 copper. The half of Fig. 533. Chronoyneter Balance. 2. (Horology.) The oscillating or pendulum wheel of a watch, which gives the pulsa- tions. Its a.xis is the verge. In the earliest clocks it was in the form of a bal- ance, and not of a wheel. It cousist- Rober^s Alloy Balance. the beam is divided into 50 equal parts, numliered from the one end, and, the point of suspension being adjusted proportionally, the weight ic is brought to a position where it enables the beam of the empty balance to stand in cqnilibrio. A quantity of copjier being then placed in the scale suspended from the short ann will be balanced by the proportionate (pian- tity of tin in the other scale. See table in Alloy, for converting fractions of apoundtodecimal proportions. Bal'ance-bar. {Hydraulic Engineering.) A heavy licam bolted to the miter-post of a canal-lock gate, and resting upon the heel-post of the same. It extends over the wharf or pier wlien the gate is closed, and has two uses,— it forms a lever by which the gate is swung on its pintle, and it partially balances the outer end of the gate. Bal'ance-bob. A weight on the inner end of a working-beam, to counterbalance the weight of the plunger-piston. The balance-bob of the Wicksteed BALANCE-BRIDGE. 21; BALAXCE-GATE. engine of the East London water-works is a recepta- cle of ballast, weighing about 89,600 iiounds. Balance-bridge. A lifting bridge with a coun- terpoise. A l-i-\.s(T'LE Bridge, which see. Bal'ance-crane. A crane having two amis, one of wliich is provided with ari'angements for counter- poising, in whole or part, the weight to be raised by the other. The following is a description of that employed by Stevenson in the erection of the Skenyvore Light- house. a 6 is a portion of a cast-iron pipe or pillar erected in the center of the tower, and susceptible of being lengthened as the tower rose, by means of additional pieces of pillar let in by spigot and faucet joints. On this pillar a frame of iron Wiis placed, capable of re- volving freely round it, and carrying two trussed arms and a double train of barrels and gearing, worked by men standing on the stages S S, wliich revolved round a b, along with the framework of the crane from which they hung. On the one aim hung a cylindric weight of cast-iron, }F, which could be moved along it by means of the gearing, so as to increase or diminish by leverage its efl'ect as a coun- terpoise ; and on the other was a roller E. The roller was so connected with the weight on the oppo- site arm as to move along with it, receding from or approaching to the center pillar of iron in the same manner as the weight did. From the roller hung a sheave, over which a chain moved, with a hook B at the end for raising the stones. When a stone was to be raised, the weight and the sheave were drawn out to the end of the arras at P of the crane, which projected over the outside of the walls of the tower ; and they were held in their places by simply locking the gearing which moved them. The second traui of gearing was then brought into play to work the chain which hung over the sheave, and so to raise Fig. 531. Balancf 'Crane used at Skerryvore. the stone to a hight sufScient to clear the top of the wall. WTien in that position, the first train of gearing was slowly unlocked, and the slight decliv- it}' inwards from the end of the arms formed an /?i- clined plane, along which the roller carrying the sheave was allowed slowly to move (one man using a break on the gearing to prevent a rapid run), while the first train of gearing was slowly wound by the others, so as to take up the chain which passed over the sheave, and thus to keep the stone fram descend- ing too low in proportion as it approached the center of the tower. When the stone so raised had reached such a position as to liang right over the wall, the crane was made to turn round the centre column in any direction that was necessary, in order to bring it exactly above the place where it was to be set ; and, by working either train of gearing, it could be moveil hori2ontally or vertically in any way that was required. Bal'ance E'lec-trom'e-ter. An instrument liaving the poised beam of the ordinary balance, and adapted to estimate, by weights suspended from one arm, the mutual attraction of ojipositely electrified surfaces. In H.\RRis's electrometer the beam is suspended from an insulated post ; one scale, carmngthe weight, has its seat upon a post ; the other scale is a disk which is suspended above a similar disk electrized by connection with a charged Leyden jar. Henley's quadrant electrometer has a pendulous pith-ball whose deflections are measured by a graduated arc. Bal'ance-frames. {SkipbuHding.) Those frames of a ship which are of equal area and equally distant from the shiip's center of gravity. Bal'ance-gate. (Hydraulic Enejincering.) A form of flood-gate which has a vertical shaft as a cen- ter. As the leaves on each .side of the pintle are of equal area, a very small power is necessaiy to open them in wliichever direction the water may be press- ing. By giving a preponderating area to the inner BALANCE, HYDROSTATIC. 216 BALANCE-WHEEL FILE. leaves of the gate, they may be made self-opening or self-closing as the current sets in or out of a chan- nel. In this form they are commonly used as sluice- gates in Holland. Fig. 535. Balance- Gates, Bal'ance, Hy'dro-stat'ic. See Specific-Grav- ity Hai.antk. Bal'auce-lev'el. (Suroet/ing.) An instrument suspcniU'd liy a ring. Wlicn in cfjuilibrium, two siglits, projierly fitted to the instrument, show the line of level. Bal'ance-knife. {Cutlery.) A tahle-knife, of wliiili llic lilailc and handle counterbalance each other, so that the blade may not touch and soil tile cloth. Bal'auce-reef. (Nauliccd.) In a square sail, a diagonal reef-band from the outer head-earing to the tack. In a fore-and-aft sail, it extends from near the outer point of the upper horizontal reef-band to a point liigher a\i at the inner edge of the sail. Baraiice-rynd. {Mill.) An iron bar stretch- ing aiross the eye of the runner, and by whicli it is poised on the top of the spindle. In the illustration, / is the spindle of the runner ; B the cock-head, on which the halance-rtjnd F F i^ poised. The lat- ter has a capacity for rocking back and Ibrtli on the Fig. 536. Balance- Rynd, spiuillc to a given extent, as the runiur iinds its ad- justment on the bed-stone. The driving-block D D sits on the scjuare of the spindle, and the driving- lugs C C bear in the slots of the balance-rynd, and drive the stone when the spindle /is rotated. Bal'ance-sec'tion. {Shipbuilding.) One of a pair of vertical cross-sections, one near each end of the vessel, which are designed after the midship sec- tion and leading water-line. Bal'ance Ther-mom'e-ter. A thermometer poised on an a.vis, and liaving ether and mercury in the respective ends. When an unusual heat occ\n's, the ether is expanded, and drives the mercury far- tlier towards the end, which tips the instrument and sounds an alarm. A form oi fire-alarm. Another form oi balance thermometer is an inverted tube, whiidi acts as a countei-poise to a window, reg- ister, or damper. The upper end of the tube has an air-bulb, the lower end of the stem containing mer- cury, into a cup of wliich the end is submerged. As the temperature increases, the air expands, displaces the mercury, the tube rises, and the window or damper is moved. The converse operation takes place when the temperature falls. See Theumometeu. Bal'ance -valve. A valve of any character in wliicli steam is ai-lmitted to both sides, so as to render it more readily operated by relieving its pressure upon the seat. Tlu' balance puppet-valve has two disks of slightly dillering diameter, and placed on a single stem ; the steam being admitted between the two, or above and below the upper and lower disk respec- tively. The slight dift'ei'ence in size is in favor of the pressure of the valve on the seat. The object is to secure a large opening without gi'cat i-esistani-e. Bal'ance-vise. ( Watchmaking. ) A small tail- vise, used liy watchmakers. Bal'ance-wheel. In horology this signifies the ratcliet-fiiinied scape-wheel in the old vertical -movc- virnt watch. Its teeth are acted upon by the pallets of the verge .S, wliich is the Fig. 63T\ axisorspindle ^. of the balance t', and the lat- ter, in its os- c i 1 1 a t i n , makes the time-beat, act- ing as the pen- dulum in a clock. The term balance-wheel is sometimes applied to the balance C, wliich acts as tlie measurer of time, and balances or regulates the rate by api dying its pulsations to intermit the action of the spring. So the term balance-wheel has grad- ually been conferred upon tly-wlieels which confer regularity of motion to the machinery to which they are applied. The term balance is derived from its oiiginal form, consisting of weighted arms ujion an oscillating axis, and having a semblance to the beam of the bal- ance when it oscillates on its pivot or bearings. This was the form of the balance in Henry de Wick's clock, constructed for Charles V., in 1379. Bal'ance--wheel En'gine. (Horology.) An instrumint for Ibrming tlie ordinary balance-wheel of a watch, which consists of a four-spoked, full- rimmed wheel of steel, and is made of a steel disk from which the segments are punched out, the cros.ifd irhcel being finished by a file. Barance-wheel File. (Horology.) Or Swing- wheel File. A file adai>te^ Bales. Ba-leen.' The plates of fibrous material with a bristly f.iiii .is^Sfc^at. ...^^a^sl 5fi Bale- Ties. In connection with the subject of ties for bales may- be nientioneil the devices for baling cut hay, anil for haling feed and forage rations, to condense their bulk for transportation. Tln> latter are especially intended for military and emigrant purposes. One plan is briefly as follows : — The hay is carried by an endless apron to a rotary cutter driven by power, and which, cutting past a fixed blade, chops the hay into pieces of from three fourths of an inch to one and a half inches in length. After this it passes through a winnowing apparatus, wliich abstracts all dust and dirt therefrom, and then between crushing-rollers, which crush it flat and ren- der it soft and flexible ; in this condition it is jjlaced in a strong press and compressed into a bale of great solidity and compactness, which, when propeily hooped or banded, is ready for transportation. By these means the size of bale for a given weiglit of hay is materially reduced, while the thorough re- moval of dust, etc., and the softening of the mate- rial fiom the crushing to which it has been subjected, increase its value for feeding purposes. The bales contain about nine cubic feet, and weigh 200 pounds. In baling forage rations, a feed of corn is placed in a feed of hay, and the whole condensed into the shape of a large brick. Baring-ma-chiue'. (Uydraidk Eiu/inceriiu].) An apparatus consisting of a square bucket, sliding on a nearly vertical rabbeted beam, dijiping at its lower position into the water in the hold or ditch, and discharging its contents upon deck. The bucket has a Hap-valve at bottom, which opens when it reaches the water. It is hoisted by means of tackle. When the bucket reaches the top, a ]iai't of the slide tilts over and tips the bucket, which dis- charges its contents. See also B.\il-sc'oop. Bal'ing-press. A press for condensing fibrous articles of considerable bulk into a compact form, (or the purpose of shipment. It essentially consists of a bed, inclosing sides, and a head, jilaten, or follower, operated by means of screws, toggles, beaters, rojje and pulley, or by other mechanical devices, as will hereafter appear. The varieties may be thus enumerated, and will be considered in their alphabetical position under the following heads ; — 1. Screw press. 7. Double-acting press. 2. Toggle press. 8. Windlass press. 3. Beater press. 9. Hack and pinion press. 4. Revolving press. 10. Reiuessing press. 5. Hydraulic press. 11. Rolling-pressure press. 6. Portable press. Other minor varieties and sub-varieties might be cited were there any object in multiplying defini- tions. Ba-lise' ; Ba-lize'. A timber frame raised as a beacon or lanilmark. Balk. 1. (Caiycnlry.) a. A squared timber, long or short, suitable fot a bcnm in a frame, a tic in a truss, a cjirchr in a floor, a sill in a building, or for a shore or chock when of shorter proportions. Baulk ; Bauk ; Bawk. b. A large timber in a fi'ame, trestle, truss, or floor. c. A whole timbei'. Technically, over 13 inches square. Half-timber is 6^ inches square. 2. (Militarii Engineering.) A longitudinal timber of a ponton -bridge. Ball. 1. (Games.) A sphere of ivory, wood, etc., used in billiards, bagatelle, crwiuet, and other games. Balls for playing are made of various sizes and ma- terials, according to their intended purpose. That, pei'haps, most familiai'ly known, is ordinarily com- posed of an interior core of india-rubber, usually, if not always, made up of strips wound into spherical form, around which is wound woolen yarn, the whole being covered with leather. JIany are also made wholly of india-rubber, and hollow. Billiard-balls are made of ivory, that substance combining in the highest degree the required quali- ties of resiliency and durability. Ten-jiin balls are of lignum-vita;. Bo.xwood is pi-eferred for croquet- balls. See also IvoiiY, artificial. The game of ball is mentioned by Homer (Oih/s- scy, viii. 372), and was credited by Plato to the Egyptians, among whom it was known in the twelfth dynasty, say 2000 B. c. The Athenians erected a statue to Aristonicus on account of his skill in ball-playing. BALLAHOKE. 219 BALLAST CAR. Foot-ball is very much iu vogue among the Amer- ica!] Indiaiis, large parties of whom participate in tile sport. Its practice among the Indians of the Plains is well described in Catlin's " North Amer- ican Indians." Tenuis was played in England in the sixteent.h century. The tennis-court at St. Janres's was erected in 1676. This game was for many years a favorite amusement with the nobility of England and France. The invention of billiards is ascribed to Delvigue, 1571. "We find cricket first mentioned in 1719. Croquet was introduced into England fi-om Ger- many in 1S30 ; its pojiularity in America hardly dates hack more than a decade. 2. (Projectiles.) A missile to be projected from a fire-arm, c. g. a bullet or cannon-ball. These are made of lead for small-arms, and of cast-iron for cannon, though in countries where copper was plentiful and iron scarce, as in South America and ile.'cico, the for- mer metal was employed, even when imported cast- iron cannon were used. The lack of tin, and per- haps want of skill, forbade the people of those coun- tries to cast bronze ordnance, though they could make copper shot. Weight of Cast-iron Balls. A joint formed by a .511. Diameter in Weight in Diameter in Weight in luclies. Pounds. Inches. Ponnds. 1 .1377 6i 42.34 IJ .'268 7 47 23 It .41H 71 52 46 1} .737 71 58.09 2 1.10 7} 64 09 2t ID'S 8 70 60 2t 2.1.5 8i 77.31 2| 2 81 Si 84.56 3 371 St 92 21 31 4.71 9 100 33 3 5.90 91 10S93 ^ 7.26 9.* lis 05 4* 8..S1 n 127.62 41 10.53 10 13r70 4; 12 51 101 ll-!.23 *J 141-5 I'H 1.59.51 5' 17.21 10} 171.06 6i 19.92 11 183 27 5* 22 89 111 19)) 05 5i 26.17 IH 209 42 6 29.71 lU 223 33 61 as 61 12 233.M 6i 37.81 3. (Printing.) A dabber for inking type or calico- printing blocks. Its mission is nearly ended in either capacity. It consists of a piece of buckskin stutfed with wool so as to form a ball, and furnished with a handle. The corre^onding device used by the en- graver in spreading etching-ground is called a clctb- bcr. 4. (Fabrics.) A round cop of thread or yarn. 5. (ilctal-icorking.) A spherical tool for cutting ; such as those for excavating bullet-molds, carious teeth, etc. 6. (Metallurgy.) A loop (Fr. loupe; Ger. luppe) or mass of iron gathered into a lump iu a piiddling- furnaee, and in a condition fit for the squeezer or tilt-hammer. 7. {Mac/liner)/.) a. A spherical valve, operated by the passing fluid, and limited as to its extent of motion by a cage, or by the size of the chamber. b. One portion of that universal joint which con- sists of a ball gripped by a box and ring. 8. (Horological.) The weight at the bottom of a pendulum, sometimes called the bob. Balla-hore. (XniUicnl.) A West India schooner ■with fore and aft sails only ; the foremast rakes for- ward, the mainmast aft. .^ Sall-anil-Socktt Joint. Ball-and-sock'et Joint. ball working in a hollow cup or socket, which allows it free motion in eveiy direc- tion within certain limits. See ITxivERS.iL JoiXT. Bal'last 1. (Rail way Engineering.) Gravel, bro- ken stone, or cinders placed beueathandaround the sleep- ers of a railroad track, form- ing a solid bed which will not retain water. Drainage must be provided below the bal- lasting. In England, where it is also called metal, two- feet bed of ballast is deemed sufficient, no water being al- lowed to stand within a depth of four feet below the rails. Ballast has four duties to perform : — a. To distribute the bear- ing over the surface of the earthwork. b. To confine the track in place. c. To permit tb-ainage of the surface. d. To afl'ord a certain degree of elasticity. A solid rock sub-way is too unyielding, and injures the loll- ing stock. Burned clay is a fair material. Cinders, shells, and small coal are also used in certain lo- calities. 2. (A'autical.) Weight in the bottom of a boat or the hold of a vessel, to keep it upright in the water, and prevent its being ujjset by the force of the wind or the weight of its top-heimpcr. On board vessels of war pig-iron is generally em- ployed for ballast ; that of the British navy consists of iron pigs of about 300 pounds each. Means have been provided for using water as bal- last. Its evident convenience, both as to accessibil- ity and facility of removal, have induced considerable pains to be incurred in devices for containing it. The employment of water-tight bags has been sev- eral times attempted. These, when empty, are stoied away in large boxes, and when required are spread out in the hold and filled by a connecting hose. There are evident objections to this mode. Iron tanks have been built into the ship, occupy- ing positions on the floor, and at the stem and stern next to the dearl-wooel. Tanks made by two bulkheads across the vessel have also been used. These are made of such a size that they may be used for coals or cargo when the ballast is not recpiired. The reservoir, whatever form it may have, must be quite full, to prevent the swa.sh- ing of the water, and the bulkhead tank has been found difiicult to fill and keep tight. The plan suggested by Grantham, of Liverpool, — a di.stinguished authority on the subject, — is spe- cially adapted for siiips carrying coal, where little or no back freight is to be "had. See Grantham's " Iron .Ships," Weale's Series. Bal'last Car or Wagon. (Bail way En- gineering.) A dumping-car for transporting bal- last for the road- bed. In the illustra- tion is seen the Fig 542. Ballast Car (English form). BALLAST-ENGINE. 220 BALLING-TOOL. English form, having a capacity for dumping to the ivar or towards i.'ither side. See Dumping-Car. Bal'last-en'gine. 1. (Hydraulic EiujiHeerimj.) A ilri'ilging-iiwchiiie for raising shingle from the bot- tom of a river for ballasting vessels. 2. (Ciiiil Etujuiccriiig.) A steam-engine employed iu e.\cavating and shoveling gravel for ballasting a road-bed. Bal'last-heav'er. (ffi/drauHc Engineering.) A dr''il,'iiig-i)rirliiin' lor raising ballast from a river-bed. Ballasting (Engineering.) a. Tlie gravel or brolci'U sto;ii', known as metal, which forms tlie roa 1. b. The material beneath and around the sleepers of the nerni'tneitt ir'Hf of a railroad. See B.\LL.\s'l'. Bal'last-light'er. (Xautical.) A barge for con- veyiir,' lpill.i»t to a vessel. Bal'last-shov'el. (Nautical.) A square-bodied and s- n-]ioiutrd iiou shovel. Ball-cal'i-ber. A ring-gage for testing the di- ani'ti-r of i;uii-.'.hot on lioard ship. BaU-cart'ridge. For small-arms ; powder and ball in an envelope. In contradis- tinetion to 6/aiii"- cartridge. See Cai;i|!I1»;k. Ball-cast'er. A caster for fur- niture, I'tc, having a sphere or ball instead of a common roller at bot- tom. Ball-oock. A faucet which is opened en' closed by means of a ball floating on the surface of the water in the vessel, allowing the cock to remain open until the water has attained a certain hight, when it is Ajlosed by means of a rod con- nection with the rising ball, fall- ing again as water is withdrawn from the vessel. It constitutes an autouiatic arrangement for keeping the water at Ball- Caster. Fig. 5«. certain hight. It is useful incisterns, watei'-backs, boil- ers, etc., where the supply is constant, the demand inter- mittent. Ball-gud'geon. A pivot of a splier- „„_ , ieaU'oiinwliichiier- nuts lateral dellec- tion of the arbor or shaft, while retaining the pivot in its soi-ket. BaU'iag Fur'nace. (Metalliirgii.) A furnace in wliich /)(7f..< 01- fiijut.1 of iron are heated so as to form balls for rolling. In t\\t puddling -furnace, pig-iron is boiled to drive otf certain impurities, and the iron therein is formed into balls by tlie ruhhle or paddle of the puddler, so as to be ready for the shingling- himmer or the sipieezer which drives the slag from tlie bloom. At the same heat the iron may be rolled ami become a merchantable article of bar-iron ; but with some qualities of iron, and for the produrtion of the liner varieties of bar and sheet iron, the bar from the first rolling is cut up by tlie shears, and made into piles or fagots, which are reheated to form ba'ls ibr re-rolling. The furnace resembles a puddling-furnace, with the exception that it is not designed for stirring and puddling, but the pilct or fagots are laid upon the floor of the reverlieratiug chamber, and are there lieated without running together, each being with- drawn as it attains tlie required condition. The bottom is made up from time to time with sand. It is not a mere reheating, but the action of the fire and the a, and pulled a ribbon through an orifice in the fi.xed framework. The length of the ribbon witlidrawn is considered equal to the chord of the arc of vibration. The use of the pendulum depends upon the dy- namical fact that if' a body of small mass impinge with great velocity upon a much larger body at rest, and the two bodies after impact move on together with a velocity which can be easily measured, the masses of the two bodies being given the whole mo- mentum after impact is known ; and as this is the momentum of the smaller body before impact, the velocity with which it struck the larger body can be determined. As now used, the block consists of a cast-iron case or mortar, partially filled with hags of sand or a block of lead. It is suspended by wrougbt-iron bars from an axis \vorking on knife-edges in V-grooves, and the arc of vibration is measured on a copper arc by an index carrying a vernier. The arc of vibration being ascertained, the follow- ing points must be known, in order to calculate the velocity of the ball on striking : — 1 . Tile respective weights of the ball and pendulum. 2. The distance of the centers of oscillation or percussion from the axis of suspension. 3. The distance of the center of gravity from the axis of suspension. 4. The angular velocity of the pendulum cfter impact. The upper figure represents the pendulum for small-arms ; the lower one for ordnance. The gun itself has been swung on a pendulum, and its arc of recoil measured to furnish datum for estimating the force of the discharge. It is also used to determine the quality of powder. See also Eprouvette. The Chronoscope and Elcetro-Ballistic apparatus afford more perfect means of determining the point sought. See Chronoscope : Elkctro Ballist.a.. Ball-le'ver. A lever having a ball affixed at one end as a weight, which closes tlie plug of a cistern when the water has risen sufliciently. See Ball- cock . Ballon. 1. {Chemical. ) A large glass receiver in the forai of a hollow globe, appertaining to a set of chemical apparatus. 2. (Xautical.) A long, brigantine-rigged vessel, used in Siam, and made out of a single tnmk. Bal-loon'. 1. A bag or envelope of silk or other thin textile fabric, around which is a netting of small rope or cord, from which is suspended a car or basket. Tlie balloon is provided with a valve, controlled by a rope within reach of a person in the car, to allow the gas by which the balloon is inflated to escape when it is desired to descend. Galien, of Avignon, wrote on aerostation in 1575 ; BALLOON. 222 BALLOON. but tliu discovery of hydrogen made by Cavendish, in England, seemed to offer a feasible mode 'of ac- coniiilishing the object, and its use was suggested for that inirjiose by Dr. Black, in 1767, who ascer- tained that a light envelope tilled with this gas would ascend. Jig. 548. Balloon. ' The first machine by which an ascent was made into the ujiper regions of the atmosjihere was invented and constructed by the bi'others .Stephen and Joseph Montgolfier, paper-manufacturers at Annotay, near Lyons, France. After e.xpeiimenting unsuccessfully with hydrogen-gas, they tried heating the air con- tained in the balloon by means of a tire in its open mouth, and in June, 1783, a captive balloon was by this means caused to ascend over 2, 000 yards. Novem- ber 21, 1783, Pilatre ile Rozier and the Marquis d'.'^r- landes ascended in a lialloon of this kind, reaching a hight of 3,000 feet, and landing nearly six miles from where they arose. December 1 of the same year, MM. Charles and Robert ascended in a balloon inflated with hydrogen-gas, alighting in an hour and ^hree quarters at a spot about 25 miles from Paris, whence they had set out, and attaining an elevation of about 9,700 feet. After this, balloon ascensions, both in France and England, became comparatively fre(iuent. The English Channel was crossed by a balloon ; and in making a similar attempt, Pilatre de Rozier and a companion named Romain were killed. Tliey had employed, in conjunction with a hydrogen-lialloou, a niontgoltiere or hre-balloon below it, and on reach- ing a considerable hight, the expansion of the gas caused it to flow downward directly upon the fire, inflaming the whole apparatus, which was speedily consumed, precipitating the aeronauts to the earth. Balloons were introduced into the French armies .at an eaily period during the wars of the Revolution, and were used at the battles of Liege, Fhnirus, 1794, and at the sieges of Maintz (XLayence) and Ehren- breitstein, where they were found particularly use- ful, as only by such means could operations in the elevated citadel be observed. "The French armies are attended with a new spe- cies of reconnoitering engineers, whose duty it is to do everytliing relative to the preparation and use of balloons. The person who mounts in the balloon is furnished with paji^T and pencils of diHerent col- ors. The marks are made according to a system agreed on beforehand, and the paper, after being marked, is attached to a small rod like an arrow, one enil of which is loaded and pointed, so that it strikes in the ground and stands upright." — Annual Jic'jlsfcr, 1794. Balloons Were also employed by the French in the Italian campaign of 1859, at Solferino ; and subse- quently, dviring our own civil war, a small corps of balloonists was attached to the Army of the Potomac. The celebrated French chemist. Gay Lussac, in 1804 reached the hight of 23,040 feet, ancf carried up with him the necessary means for making scientific obser- vations on the character and properties of the atmos- phere at that great hight. This was for many years considered the most remarkable balloon ascent ever made, both in regard to the hight attained and the observations made. The gi'eat tenuity of the atmos- phere in those elevated regions is said to have atfected M. Lussac to such a degi'ee that his system never fully recovered from it. An English aeronaut named Glaisher, it is said, has recently succeeded in reach- ing the hight of seven miles. He was lendered seri- ously ill, and was supposed to have burst some blood- vessels. Charles Green introduced the practice of inflating balloons with ordinary illuminating-gas, making his first ascension with this medium on the day of the coronation of George IV., 1820. llluminating-g,a,s, besides being much cheaper than hydrogen, has the advantage of being more easily retained within the envelope on account of its greater density. In 1836, Jlessrs. Holland, JLason, and Green as- cended from London in a balloon of 85,000 feet capacity, taking with them a ton of ballast, a fort- night's provisions, extra clothing, etc. They land d next day in the duchy of Nalssau, having made a voyage of aliout 500 miles. In June, 1859, Jlr. Wise, the well-known Ameri- can balloonist, ascended from St. Louis and landed in Jeti'erson County, N. Y., having traveled about 1,150 miles. Gilford's captive balloon, noted as one of the fea- tures of the Paris Exposition of 1867, was 93 feet in di.ameter, having a capacity of 421,161 cubic feet; weighed 6,000 pounds, the netting and guy-ropes weighing 4,000 pounds additional. It was inflated with pure hydrogen-gas, and the car accommodated twenty-five persons. The roiJe by which it was held tapered graclually towards its lower end, so that in case of parting it would break near the ground, and not endanger bystanders. It was wound round a drum turned by a steam-engine. The cost of the balloon with its "appurtenances, including inachineiy, was over .545,000. M. Dupuy de Lome attempted a few years ago the construction of a navigalile balloon of consider- able dimensions. In order to maintain its |ierma- nence of form, a large balloon was provided with two interior suspended tubes, whose open lower ends com- municated with the air ; a small interior balloon with valves was placed inside of the larger one, and by its greater or less inflation compressed the tubes more or less, causing the contained gas to rise or fall, so as to cause a uniform tension of the surrounding gas contained in the larger h.^Uoon. The longer di- ameter of this latter was parallel to its axis of motion, and the ajiparatus was to be propelled by a screw attached to the car and operated by hand-power. The rudder was a triangular sail att.ached at its BALLOON. 223 BALLOT-BOX. lower edge to a pivoted hoiizontal yard beneath the car, near its rear, and operated by a rope at each end, extending to tlie steersman's seat. Tlie British military authorities assume that a hight of 100 fatlioms at a distance of 600 fathoms from an enemy aH'ords an ample Held of view. Cam- eras arranged so as to include the whole horizon, enable tlie country to be pliotogi'aphed, and tele- graph-wires, which can be paid out as fast as the balloon sails, afford communication with the earth or with another balloon. Experiments made at Tours show that at a higVt of 1,000 to 1,200 yards the silk envelope of a bal- loon could be penetrated by bullets, but that the escape of gas w;is so slow that with a favor.able wiml the balloon might reach several miles before falling. At 2,700 yards the best shots failed to penetrate the silk ; and this elevation is therefore considered the miximum necessary to insure safety. The late Prussian and French war, and especially the siege of Paris, gave rise to the most business-like and systematic use of balloons on record. The man- ufacture is thus described by a newspaper coiTcspond- ent : — " The type of the balloons constructed by M. Godard for the Postal Administration is entirely spherical. The proportions are as follows: Diameter, 16 yards; superficies, about 836 square yards ; volume, 6,316 cubic yards. The stuff employed is a strong glazed cambric, oiled and varnished. With machinery, forty thicknesses of this cambric arecutoutatonetime. Af- ter this operation these strips are sewed together with a double waxed white thread, and the balloon is re- peatedly rubbed with oil, in order to secure its imper- meability. A valve in strong wood is set into the upper pole of the balloon ; this valve is closed by india- rubber springs. A long cord is attached to this valve, and traverses the lower pole, enabling the aeronaut to regulate the descent of the balloon. A network of tarred twine envelopes the balloon. To the extremity of this net a wooden hoop is adjusted, to sustain the wicker-work basket, which measures about 3 feet in width and ii in length. Benches are provided for six persons. Around the basket the sand-bags and dispatch-bags, with three hundred yards of rope, are ranged. This latter provision is intended for throwing out to drag on the ground and diminishing the speed on descending. " The weight, when filled with ordinary burning- gas is about a ton, comprising sL\ hundred pounds of sand-bags, three persons weighing about 150 pounds each, and 1,000 pounds of dispatches. It requires ten days for the manufacture of each. The cost of each is §1,200." Carrier-pigeons, also, were much used by the Pa- risians during the Prussian investment of that city. The Hying messengers who have their homes in Paris alforded the means of communicating with the be- leaguered city. The use of carrier-pigeons is very ancient. On a temple-wall in Egj-pt there is a sculpture of the time of Rameses II. (1297 B. c. ), representing that monarch proceeding in regal state to assume the crown of Upper and Lower Egypt ; and in the procession a priest is seen releasing from a basket four carrier-pigeons, to announce the ti- dings to distant points. Ovid relates that Taurosthenes announced to his father in ^Egeria, by a pigeon stained purple, that he had obtained the prize at the Olympic games. Brutus used pigeons for communicating with the in- habitants of Modena, during its siege by Marc Antony. AVlien Ptole!nais in Syria was invested by the French and Venetians, and was about to surrender, a carrier- pigeon, bearing a message from the Sultan, was cap- tured ; the missive containing promises of assistance was removed, and one substituted in which the Sul- tan expressed no hope of being able to assist them. The surrender was immediate. Pigeons were of great use to the Dutch during the siege of Leydeu, so bravely resisted by the Prince of Orange. The air-car is a proposed form of balloon, inflated with gas to secure lightness, and traveling upon wires stretched from pillars upon a definite route. Two pairs of wires are needed, — one pair for each side of the car, — and the upper and under wires of the respective pair run in the grooved peripheries of the car-wheels, which are rotated by a steam-engine on board. The car is cigar-shaped, and has sails to be used with favoring winds. The device for passing the posts is ingenious, but does not differ substan- tially from the mode of hanging the tracks of caster- wheels for sliding barn-doors. Signals have been made, and notices, etc., have been distributed, by means of balloons. One was invented by Mr. Sheiiherd, and used in the Arctic regions in the search for Sir John Franklin. The arrangement consisted of a number of printed pack- ets of oiled silk or paper, upon which directions were printed, stating the latitude and longitude of the exploring ships, where they were going to, and the points at which provisions had been left. These were attached at proper intervals to a long slow- match made of rope dipped in niter ; and as the bal- loon traveled over the country, the match burned gradually away, releasing the jiackets consecutively, and distributing them over a wide extent of country. Other devices were also adopted for the same pur- pose, and are described under Signals. 2. [Architecture.) a. A mold at the base of a column. b. A round globe at the top of a pillar. 3. (Glass.) A glass receiver of a spherical form. 4. (Fabric.) A cylindiical reel on which sized woolen yarn for warp is wound, in order to be dried by rapid revolution in a steam-heated chamber. The yarns are guided by passing between the teeth of a separator or rarel, which is a toothed instrument like a rake, between whose teeth the j'arns pass. This acts as a guide in distributing the yarns over the length of the reel. The yarns are wound from the balloon on to the beam of the loom. Bal-loon'-jib. (Kautical.) A triangular sail, used in a cutter, and hauled up to the topmast -head. Sometimes called a, jib-topsail. Bal-loon'-net. (Fabric.) A variety of woven lace, in which the weft threads are twisted in a pe- culiar manner around the warps. Bal'lot-box. A box in which balls or beans indicating a negative or affirmative, or slips contain- ing the names of candidates for office, are deposited. Ballot-boxes of the ordinary construction afi'ord no security from fraud, except the honesty and attention to duty of the receivers of ballots. To guard against the improper placing of tickets in the boxes, they have been made of glass, so that the interior might be open to the inspection of the bystanders, and any surreptitious introduction of tickets therein at once discovered. The ballot was used in ancient times. It has been suggested that of this character was the Urim and Thummim spoken of in Exodus xxviii. 30 : — "And thou [Moses] slialt put in the breastplate of judgment the Urim and the Thummim, and they shall be upon Aaron's heart when he goeth in before the Loril : and Aaron shall bear the judgment of the children of Israel upon his heart before the Lord continually." BALI-OT-BOX. BALL-TURNING LATHE. The conjecture that white and black stones were contained in tlie pocket beliind the breastplate, and, being taken out by the high-priest in consultation, gave affiiniative and negative answers respectively, is not suppiirti'il liy tlie weight of authority. It is rather supjiosed that images re]>resenting respective- ly Ur, light, and Thorn, perfection, were placed in the bi'castplate, and inted and cotton for ladies' dresses. Band. 1. (Vehicle.) A circular collar, hoop, or strap, such as that on a nave ; a hub-band ; an a.xle- band. 2. (Architecture.) a. A narrow, flat projecting surface. When narrow, it is a fillet ; wider, it is a facia. b. The leaden came which holds the lozenge-shaped panes in the old-fasliioned casement windows. 3. {Fire-Arms.) One of the metallic sleeves which bind the barrel to the stock of a musket, etc. 4. (Bookbinding.) a. One of the cords at the back of a book to wliich the thread is attached in sewing. Though now a cord, it was formerly a flat band, and hence the name. It usually, in the better forms of binding, makes a raised (irojection on the back, and in large blank-books is formed by glueing strips of mill-board or leather across the back. In a fine bre\iary of the fourteenth century, in J. S. Griii- nell's collection, it is a thick, roundi-d, white leather cord secured to beechwood side-boards. 15 b. The head-band serves as a finish to the top and bottom of the sheets, and helps to keep the upper and lower parts of the back in shape when the book is closed. 5. (Husbandri/.) A bundle of eight or ten stalks of wheat, or other small grain, used to bind a gavel of the grain into a sheaf. Corn-shocks are bound with stalks, or with string, linn-bark (linden or bass), or rye-straw. String or wire is the usual band on the automatic binding apparatus of reaping and binding machines, but a bunch of straw out of the sheaf is used in some machines. • 6. (Machinery.) A flexible connection between pulleys, generally endless, but sometimes attached by its respective ends to reciprocating sectors, or a sector and slide. Bands may be classed as belts, cords, or chains. A belt is generally flat and thin, and requires a nearly cylindrical pulley. A cord is usually circular in section, and made of catgut, raw-hide, twisted fibers, or wire. It requires a grooved pulley. A chain consists of links or jointed bars, and re- quires a grooved, notched, or toothed drum. 7. A cincture, strap, or cord, with a means of fastening the ends together, and used to confine the materials of a bale, truss, or bundle. See B.\LE-TIE. Baud'age. (.'iurgicat.) A strip or piece of fabric, cotton, linen, or woolen, or an elastic, knitted, or shirred fabric for wrapping any part of the body. They are applied to dress fractured or lacerated parts, for the comjiression of bloodvessels and the retention in tlieii' natural situations of protruding or displaced parts. Thej- are simple or compound. They are named from their purposes, as — Uniting, dividing, exjxlling, relMning, compress- ing, suspeiisory, varicose-rein, fracture, catamenial. They are named from their iorms, as — The axia, like an axe. The spica, like an ear of wheat. The capistrum, a split cloth bandage to support the lower jaw. The chiustcr, a cross-shaped bandage for stopping hemoiThages from the temporal artery. The i-taiUd bandage, made from a single split cloth, and also known as Galen's. The figure 8, the T, the letter D, the stellated, or star-shaped, the circular, the spiral, the reversed, the IS-tailed, etc. They are also named from the materials with which they are treated, as starch, dextrine, plaster of pans, etc. Ban-dan'na. (Fabric.) An India silk, printed in one color with white spots or ornaments made by the resist or the disehttrijing process. Bandannois. In the resist process, the spots are printed with a composition to resist the dye by which the ground- color is given. Subsequent washing then removesthe dye from tlie s]JOt,s, the ground-color remaining intact. In the discharging process, the whole handkerchief is dyed of one color, and is then printed in spots with a composition which discharges the dye at those points, so that, in washing, the spots come up white. One mode of making the white spots in bandanna goods is by causing a solution of chlorine to perco- late down through the red clotli in points circum- scribed and defined by the pressure of leaden pattern- plates in a hydraulic press, thereby discharging the color in certain ]>laces. Band-coup'ling. A device for uniting the two ends of a band. This may be a pair of ferrules, with BAND-CUTTING MACHINE. 226 BAND-SAW. a ball and socket respectively, a hook and eye, strap i hinges with a ]>intle, etc. See Belt-Cotpling. i Band-cut'ting Ma-chine'. (AijricuUurc.) An ( attachmi'nt to a Ihrasliing-niaehino to cut the hands ot the sheaves as they are thrown upon the feed- board. The band being cut, the sheaf is spread out and then pushed head loreniost into the Wtz-ou/, wlieuee it passes between the cylinder and the concave, each of which is toothed. In England, they prefer to save the straw in a less mangled condition, and feed in sideways ; the beaters being biu-s, not teeth. Banrf-driv'er. A tool used in correcting irregu- larities in the liauds of machinery. Band'ed Col'uma. {Architecture.) One hav- ing cini'tures at intervals. Bau'de-lore. A toy illustrating the effect of gravity in producing a rotary motion. It consists of two disks, with a deep groove between them, on which is a winding cord. The latter being coiled in the groove, the bandelore is dropped, unwinding the cord-; at the end of its stroke, the rotary motion be- ing continued, it rewinds on the cord in the opposite direction, and climbs to nearly its original bight. By a little humoring and motion of the hand, it may be made to rewind the whole length of cord. Band'ing-plane. (JVood-workUu).) The Jaiif?- vuj-plaiic is allieil to the gages, and is intended for cutting out grooves and inlaying strings and bands in straight and circular works, as in the rounded corners of piano-fortes and similar objects. It bears a general resemblance to the plow, but also has the double-pointed seorer of the grooving-plane. Tlie central plate of the plow is retained, so as to furnish a guide for tlie central positions of the router and cutter, which are inserted so as to meet at an angle of about 80' between two short portions of the central plate. The whole of the parts entering the groove are compressed within tlie space of one inch, to pass through curvatures of small radius. A flexible steel fence is attached to the plow by two stays at its ends, wliile to the central part is attached a screw adjust- ment to confer upon the fence any required cui'va- tnre, convex or concave. Band'ing-ring. (Hnl-m'tking.) Runner -down. A ring passeil over the boily of a hat while on the block, so that its edge shall impinge upon the brciih of the band, and form the brim at light angles to the crown in the process of blocking. Band'let. (Architecture.) A small fillet or mold- ing. Ban'dore. (Mime. ) An ancient stringed instru- ment resembling a lute ; referred to in Pepys's "Di- ary," 1662, — "and music with a bandore for the base ." Band-pul'ley. {ilachincnj.) A flat-faced wheel fixed on a shaft and Fig. .S52. Two-Part PuUey. driven by a band. 1 1 is connected either immediately or me- diately through oth- er pulleys, with any power which drives machinery. The illustration shows a two-] lart pul- ley, having flanges, connected by bolts and nuts, on the hub and rim. A drum. Band'rol. 1. (Archilectiire.) A form of spiral mold- ing in Gothic archi- tecture. Bandrule. 2. {Nautical.) A little streamer from a mast- head. Band-saTV. The band-saw consists of an endless steel belt running over wheels and revolved continu- ously. It is pliable, so as to conform to the laces of the wheels, and is serrated on one edge. The ends are joined by solder and by neat clamps. Arrange- ments are m:ule for straining the saw Ijy regulating the relative distance of the wheels ; this adjustment also permits the machine to take in saws of dirt'erent lengths. One advantage of the band-.saw over the reciprocating saw is, that there is no lost time in its operation, and no eflbrt required to keep the work to the table, as the action of the saw tends to this result. There is no need of a pump or blower to clear away the sawdust, as it is carried continually downward. In the machine Fig. 553. shown there are sev- /'~\_ eral adjustments: one \_/; by weighted arm a, for raising the boxing of the upper wheel, and thus straining the saw ; another by wheel b, for laising or lowering the table c, on which the work is placed ; a wheel d, by which the saw- guide c is raised or lowered, to bring it into the vicinity of the upper surface of the work ; a wheel /, by which the ta- ble is inclined when the work is to be sawed to a level. In the band-saw represented liy P"ig. 554, the standard A supports a frame, on which is an upright sliding-block and Fig. 554. Band- Saw. Band- Saw. arm .sustaining a horizontal shaft running in boxes. On this shaft is hung the upper wheel B, which, by BAND-WHEEL. 227 BANK. means of the screw aud hand-wheel C, can be ele- vated or lowered as the length of the saw demands. The lower portion of the frame, under the table, supports the lower shaft and wheel, which is driven by the pulleys D. The two wheels have a liange, against which the back of the saw bcare, and the faces of tlie wheels are covered with vulcanized rub- ber resting on a bedding of strong cloth. This gives sutticient adhesion to the saw to insure its action as a belt without slipping. From the front of the upper frame depends a ver- tical bar E, sliding in boxes, to which it may be secured, at any bight required to accominodate the stutt' to be sawed, by tlie thumb-nuts /'. On the lower end of the bar is a guide G, having four sides with recesses of varring depth, to accommodate the various width of dillerent saws. This guide is in two parts, held together by a screw-bolt, and gradu- ated in the distance of their faces by means of the screw-bolt and a four-pronged spring. The saw runs at the rate of 4,000 feet per nimute. In the English practice, tlie minimum diameter of band-saw pulley is set at 30 inches ; but for wider saws the diameter must be increased : thus saws of 2 inches to 3 inches wide ought not to be worked over pulleys of less than 42 inches in diameter, and for a blade 6 inches wide the pulleys should be 70 to SO inches. Band-'wrheel. (Macliuurry.) This is sometimes termed a pulley, — a term which has, however, par- ticular relation to tackle. The band-wheel has a nearly flat or a grooved face, according to the shape Band-WhetU of the band. If it be flat, the face of the pulley is slightly rounded so as to keep the band from run- ning oiir. If the band be round, the pulley is grooved to retain it, as in the wheel on the mandrel of the common foot-lathe. Ban'gle. 1. (Xautica!.) The hoop of a spar. 2. An ornamental ring, worn upon the arms or ankles in Asia and Africa. Ban'gra. (Fabric.) A coarse Indian cloth, made from thi' fiber of a gigantic stinging-nettle. Ban'is-ter. 1. (Architecture.) Originally, hal- uslcr. One of the vei-tical supports of a hand-rail on a balcony or staire. Also the ha7id-rnil itself. "He ascended, holding on by the banisters." The baluster has a curved outline, and is frequently provided with a base and cap, or ornamental mold- ings, while banisters may be plain or square. 2. -\ broad central upright in a chair-back. Ban'jo. 1. (^fusic.) A five-stringed musical in- strument having a head and neck like a guitar, and a body like a tambourine, consisting of a circular frame overwhich sheepskin ori>archment is stretched ; it is of almost univeisal use among the negroes in the Southern States. Its simplicity, and the ease with which it is made and played, no doubt made it such a general favorite among them. Its thrumming sound has a near resemblance to the, tan-lam of the Afri- cans and the Orient. The latter is a lizard's skin stretched over a gourd ; a tambourine, a sort of drum. The guitar appears in the sculptures of ancient Egi."pt and Ximroud, and is much used in modem Oriental countries. In the kcriiuiiijeh, or Syrian fiddle, the bridge- piece is supported upon the parchment cover of the body. 2. (iVajrftca?.) The brass fi-ame in which a screw- propeller is hung for hoisting. Bank. 1. (Cutton, etc) A creel for holding rows of bolibins ; a coppiny-plalc or coppiinj-rai/^ 2. (G/iiss.) The floor of a glass-melting furnace. 3. (Music.) A bench of keys of a stringed or wind instrument. Generally applied to organs which have Fig. 556. IttJ Double Bank. several key-boards or banks of keys belonging to the different aggregated organs, which combine to form an instrument of great power. Such instruments are made up of a choir organ, great organ, and swell, to which may be added a pedal or- gan or fool-keys, for acting on the larger pipes. Each of these is adapted for particular effects : the choir organ for light and solo parts ; the great organ for powerful effects ; the stccll for crescendo and diviviu- cndo effects. Each has its key-board, one rising above another in front of the performer, and all within convenient reach. The keys are thus airanged in three banks or tiers in the case described, and tlie keys of one bank, by a suitable device which may be thrown in or out of action as desired, may be coupled to the conespond- ing keys of another bank, so that the pressure on one is communicated to the other, to give the com- bined effect with a single manipulation. Church reed-organs on a smaller scale and of por- table size are frequently double-banked, the keys of one bank being concerned in the use of a powerful set of stops, and those of the other with other stops of a more mellow and moderate tone. See Stoi' ; OitGAN'. The organ of S. Alessandro in Colonna, at Ber- gamo, built by Serassi in 17S2, has four banks of kevs and 100 stops. The first and second bank be- long to the great organ and choir organ ; tlie third is connected by mechanism, which passes under- ground to a distance of 115 feet, to a third great organ in another part of the church opposite the fii-st. The claviers of the Continental European churches are frequently fi-xed in a detached upright console, at which the "organist sits facing the altar and con- gregation, so as to be able to watch the service and introduce the music at the projier times. 4. (Mining.) The face of the coal at which miners are working. 5. (yaulical.) a. One tier of oars in a galley. When a galley is propelled by rowei-s seated on two or more tiers of benches, one above another, the gal- ley is said to be doubk-bankcd, triple-bnnkcd, etc. b. A seat for rowers in a galley ; a thwart. BANK-ALARM TELEGRAPH. 228 BANQUETTE. Cuiniiimi galleys huve 25 banks on a side, one oar to a bank and foiu' men to an oai'. Galcasses have 32 banks on a side, and six or seven rowei-s to a bank. c. An oar is sintilc-biinked wlien it is rowed by one man. An oar is douhlr.-hanked wlien pulled by two men, as the captain's barge. This term is also some- times applied when sepai-ate oars are pulled by two men sitting on the same seat. ti. (Print inc/.) a. A wooden table for holding the paper to be fed to the hand-press. The paper is slipped off the bank on to a slanting board ealled tile horse, from whence it is taken sheet by sheet. b. The support of the moving carriage of a print- ing-press. Bank-a-larm' Tel'e-graph. An apparatus for conveying to a direetor's room, or police, notice of surj'eptitious entering of the bank, or for conveying regular notices of " .\11 's well." Bank'er. 1. {BricklaijUij.) A bench used by bricklayers in dressing bricks to a shape suitible for skew or gaged work, domes, niches, etc. On one end of it is a grit-stone called a rubbing-stone, and on other jiortions is room for operating upon the Uricks with the tin-saw, by which kerfs are made in the bricks to the depth to which they are to be hewn. An axe is used for dressing off the surface. 2. {Fine Arts.) A modeler's bench. It is about 30 inches high, and has a to|i 30 inches square. On this is a circular platform which turns on wheels, so that the figure can be revolved to expose any portion to the light. 3. (Nautical.) A vessel in the deep-sea cod-fish- ery on the NewfouniUand Banks. 4. A seat cushiou. Bank'ing. 1. (E) graving.) Raising a wall of wax aro\uul an etching on a plate, to fonn an em- banUment to hold the acid used in biting-in. See Etching. 2. {Stcam-Engincrring.) Banking up the fires consists in raking them to the bridge of the furnace, and then smothering them with cinders and small coal, the draft being at the same time checked. By this means the lires are kept in a state of languid combustion, but are ready to burn up briskly again when steam is wanted at short notice, the red-liot mass lieing then broken up, raked forward, ajid the draft readmitted. The fire is said to be drawn forward when fuel is added and the draft turned on. Bank-uote. A promissory note issued by a bank, and intended to circulate as currency. Chinese paper money was issued about A. D. 1100. " Blest paper credit," as Byron says. Genghis Khan issued pa[ier money, but all his power conld not give it a purchasing value above fifty per cent of its face. In "The Book of the Balance of Wisdom," by Al-Kliazini, a learned Arab of the twelfth century, occurs the remark that, in the first division of his book, are "added chapters on exchange and the mint, in connection with the mode of proceeding, in gen- eral, as to things salable and legal-tenders." The Bank of England commenced business at Grono's Hall, Poultry, London, in 1695. No notes were issued under £ 20. Notes of £5 were issiu^d in 1793. Bank-note En-grav'ing. The chief object in the maiuifacture of bank-notes is to render forgery impossible, or at least easy of detection. This is sought to be effected by peculiarity of paper, design, and printing ; or by a combination of these means, as' is done in the Bank of England and other banks. The mechanical design, however, has chiefly been relied on for security. 1 1 has been the constant aim to make the impression such as to render the genu- ine note readily distinguishable by the jiublic for its high art, and to the bank officials by secret peculiar- ities in its execution. Until about 1837, copper- plate printing was the only process in use for bank- notes. In that year, however, Peiikins effected his valuable improvements in practical engraving. In 1855, electrotype printing was introduced in the Bank of England by Mr. tlmee, and since that time the notes have been produced by surt'ace-printing by the electrotype. The design is engraved in relief on separate pieces of metal, — copper, biass, and steel. From the ag- gregated pieces a matrix is obtained by electro-dejio- sition, and from this a ])late is obtained by the same means. When backed and mounted the plate is used for surface-printing. In America and in the Bank of Ireland, the plates are jirepared according to Perkins's method. The se]iarate designs forming the complete bank-note are first engraved by hand on separate steel blocks, which are afterwards hardened, and are preserved as per- manent patterns not to be printed from. These engravings are transferred to the steel rollers under heavy pressure, the rollere being afterwards har- dened and used as dies to impii'ss the engraving upon the printing-plates. The engraved plates for print- ing the bank-note are made of soft steel, and are never hardened after being engraved. Being of large size, — 20 inches by 16 inches, — they would most probably lose their flatness in hardening. Another reason for not liardening the plates lies in the fact that, when worn, the soft plates are easily repaired by re-application of the rollers thereto. The printing-])late, when receiving its fir.st im- pression from the master roller or die, is fixed upon the table of a strong press, fi'om which a pressure of 10,000 ]iounds can be obtained, the ])ressure being ri'gulateil as re(iuired by means of a weighted lever. The position of two register-) loints in the jilate is accurately noted by means of a micrometer micro- scope, and registered in a book kept for the pur- pose The master-roller is then passed over the plate by the machine under the heavy jiressure, be- ing very steadily guided by a special jiaivdlel-motion arrangement. The table is provided with complete adjustments of peculiar delicacy, ami the j)ressure of the engraving roller upon the p'ate is not pro- duced by the roller descending upon the plate, but by the table being raised u]i to the roller. When a plate reipiires renewing, it is again fi.xed upon the table in the same jiosition as before by means of the micrometer microscope and the register of its position ; the roller being passed over it deepens those parts of the impression which the continuous ]irinting has worn away. Bank-pro-tec'tor. {H;/drnulic Engineering.) To prevent the washing away of banks by the action of waves or currents. See Fascine ; Gudin ; Sheet- riLiNc, ; Crib; Pitching; Retaining-wall; Dike; Sea-"\vam,, etc. Ban'ner. A small fiinged flag, depending from its staff' by cords attached to the ends of a cross- piece. Ban-quette'. 1. {Fortification.) A raised bank at the foot of the interior .slojie of a parapet, on which the soldier stands to deliver his fire. See Intrench- MENT ; Abattis. A banquette is also found in some fortifications at the foot of the counterscarp, to enable defenders to fire over the crest of the glacis. 2. {Civil Engineering.) a. A raised footway ad- joining the ]iarapet of a bridge. b. A ledge on the face of a cutting. BxVNTAM-WORK. 229 BAE-CUTTER. Ban'tam-w^ork. Painted or carved work, re- sembling that of Japan, only more gaudy. Bap ta-te'riunL A back-mill or fiiliing-mill. Bap'tis-ter-y. {Architecture.) .\ building appiT- taiiiing to a cathedral or church, or a portion of the church itself, in which the ceremony of baptism is performed. If a separate building, the baptistery was, in the earlier ages, either lie.\agoual or octago- nal in plan ; afterwards they were made polygonal, or even circular. When within the church, it is merely the inclo- sure containing the font, as in English churches of the present day. Bar. A word of various signification in different branches of the practical arts ; as 1. (Hydraulic Engineering.) a. A sedimentary deposit in a river, or at the embouchure of one. 4. A boom of logs preventing navigation. 2. (Xaulicil.) a. A lever used in a cap.stan. They are'inserted like spokes in the capstau-head, and serve to rotate it. The analogous levers in a wiudlass ai-e hdmhpikes. b. \ flat iron rod securing a hatch. c. A piece of iron or wood to secure a gun-port. 3. (Miichincnj.) a. X bar-lathe is one whose shear is a single piece, frequently triangular in sec- tion. i. A large arbor supported between the centei-s of a lathe, and carrying the cutter by which a cylinder or gun is bored out. A boring- bar. See Cylinder- BOKER ; B0RIXG-M.\CUINE. 4. {Mining.) a. A di-illing or tamping rod. b. A vein running across a lode. 0. (Weaving, etc.) A driving- bar is a movable operating part in a lace-machine. \ bar-loom is a small-ware loom. 6. (Printing.) a. The por- tion connected with the handle of* a hand printing-press, and acting to depress the platen. b. The middle, long cross- piece of a printer's chase. 7. (ffiisbandri/.) Shifting rails which are removable from their mortises iu the posts are termed bars, and the complete device Ls a sort of substitute for a field- gate. 8. (Saddlery. ) «. One of the side pieces uniting the pommel and cantle of a saddle-tree. b. The mouth-piece of a bridle-bit which connects the two checks. 9. {Furnace.) ffr(i<«- Jars or ^rc-Jara support the fuel, and rest on beurers. 10. The crowbar is an iron lever used in many ways. il. (Carpentry.) a. A horizontal piece of timber or metal connecting other portions of a framework. b. A crosswise piece of wood or metal held by staijles or bolts, and forming an inside fastening for door or shutter. c. One of the thin strips of wood forming the divisions of a sash. 12. (fehicles.) The piece to which the traces are attached ; a splinttr-bar is permanently attached to the carriage ; an equnliziny-bar, or erencr, is other- wise known as a double-free, swings on a pivot, and has a sinide-tree or ichijfle-free at each end, Bar'an-gay. {S'aviical.) An Indian vessel pro- pelled by oars. Bar'ba-can. (Fortification.) a. An advanced work to defend a bridge, gate, or approach. Other- wise, barbican. b. An embrasure. c. A channel or scupper in a parapet to discharge water. Barb-bolt. (Machinery.) One having jagged edges to prevent retraction after driving ; a rag-bolt. BarTje-cue. In the Cingalese treatment of cof- fee-berries this is the dry floor on which cofl'ee is sun- dried after the pulp is gi-ated therefrom, and the beans in their parchment en^•elcpe have undergone a preliminary soaking. It is circular, of stone, with a white plaster surface, sloping away from the center, and smooth as glass. The coH'ee is sunned upon it for four days without removing the sac, in which a pair of berries are inclosed, the object being to dry it previous to bein^ dispatched to Kandy. Barljer's Chair. One adapted for the special uses of a barber, with a vertically adjustable head- rest, arms, an elevated footstool. In some barber's chairs there are drawers and shelves for the appara- tus and appliances. Bar-bette'-gun. (Fortification.) WTien a can- non is mounted so as to be fired over the crest of the parapet instead of through an embrasure, it is said to be mounted en barbette. In field-works, a mound of earth is thrown up against the interior slope of the work ; its upper Fig. 557. BarbttU. I surface is nearly level, and of such a hight as to allow the gim, mounted on its caniage, to be fired over the crest ; a slope, termed a ramp, is made at the rear of the barbette, and descends to the tCTre- plein. The parapet may be on the summit of a fort which has lower tiers of guns iu casemate, or it may be a mere earthwork. The term barbette is from the French, as are almost all our military terms, and it means a work adapted to be fired over, and yields a certain amount of protection to the gunners, the piece, and the ammunition. The carriage is adapted to be ran "in and out of battery" on a chassis, and the latter has a circular motion on a pintle, to enable the guns to be trained horizontally. When the pintle is arranged at front, as shown in the figure, the amount of this circular motion is lim- ited ;" on a center-pintle carnage the gun may be directed toward any point of the horizon. Such a gun is cr\!led a pirnl-gun. Bar'bi-can. See Karbacan-. Bar'ca. (Xnulicil.) A Portuguese two-masted Vessel. I'sed also in the Mediterranean. Barcon. Bar-cut'ter. (^[l•tal-trorking.) A shearing-ma- chine which cuts metallic bai-s into lengths. BAREGE. 230 BARK-CUTTING MACHINE. Pig. 558. Bar- Cutter. The purposes are various, — for cutting bars into pieces for fagoting and reheating, for nail-plates, etc. Ba-rege'. (Fabric. ) A lady's thin dress-goods, all won!, plain or printed. So called from Barcijes, a to\v]i in the Pyrenees. Bare-pump. (HydrauHcs.) A portable suetion- punip lor (Irnwiug li(pior from casks. Such are used in viueirar works, in wiiu' and beer cellars, for JBare-Pitmp. sampling, etc. In the illustration the piston is hol- low, and carries a spring-valve, which closes as the piston rises, and ojiens to allow the air to escape as till' )iistou descends. Bar-frame. {Furnace.) The frame which sup- ports thi- ends of the grate-bars. Barge. {Sifaiitical.) a. A vessel or boat of state or pleasure ; as the Baccntimr, the state galley of Venice ; Cleopatra's galley ; the Lord Mayor of Lon- don's barge, etc. b. A man-of-war's boat ne.\t in size to the launch. The boat for the special use of the commander of a fleet or squadron is also called a barge. It is 30 to 32 feet long, has a beam equal to .29 to .2.5 of its length, is ttjm'?-built, and carries from 10 to 12 oars. c. A large boat for the conveyance of goods and passengers. In the United States they are frequently of 600 to 800 tons burden, have two upper decks. and are destitute of motive-power, being towed by steamboats. Barge-board. {CarjKntrt/.) A board beneath the gable, hiding the horizontal timbers. It is per- Fig. 560 Barge-Board. forated, scalloped, or crenated, to give it a light and ornamental a]ipearance. Barge-coup'le. (Carpcntr}i .) A beam mortised into ancithii- fc> sti'eiigthen the building. Barge-course. (Arcldtceturc.) n. That portion of the shingling or slating of a roof which piujects over the gable-end. b. A coping course of bricks laid edgewise and transversely on a wall. Ba'ri. The portion of a roofing-slate showing the gage, anil on which the water falls. Bar'i-tone. (Husk.) A kind of bass-viol. Ba'ri-um. A metal, the base of heavy spar (sul- phate of baryta), discovered by Davy. It is of a grayish or yellowish hue, has only been procuied in very minute quantities, and is rajiidly converted into an oxide by the action of either air or water. It has never been ajjplied to any practical use in the arts. Equivalent, 68.5 ; symbol, Ba. An oxide of barium, when reduced to a white powder, is used to adulter- ate white lead, and also as a cosmetic, — both very bad practices ; one injures the paint, and the other the complexion. Bark-cut'ting Ma-chine'. Bark is reduced to a state of minute division to enable the water to dis- solve out the tannin moie readily and perfectly. Fai!COt's Bark-catling Machine (French) is shown in side elevation and plan. A A' are two fluted cyl- inders which supply the bark previously .spread u)ion the table a to the cutting-apparatus, h is a raised ledge to keep the baik on the table. The cutting apparatus consists of two parallel cii'cles fixed upon a common axis C\ having steel plates or knives /> B, which are disposed in a spiral form. Tlie shaft G and fly-wheel S are driven by a band on the drum D. A pinion at the other end of the shaft C cariies a jiinion 7, which acts upon a wheel J on the axis of the fluted cylinder A, which is communicated hy wheel E to " cylinder A'. By the levers F F and weight G, the two cylinders A A' are regulated to any required proxiTnity. Inside the fluted cylinders is a longitudinal piece of steel b, which acts as a su])- port for the bark as it is cut by the knives B B, its edge tbrniing, as it were, one bar of the cutting- shears. The cylinder which carries the cutting- knives nuikes about 130 revolutions per minute, and the ((uantity of bark cut is about 1,600 pounds per hour. BARKER'S-MILL. 231 BAEKIXG-TOOLS. Fig. 561. j "iiiiii iijiiiiiiiinaijii j Bark-Cutting Mcuhine. Bark'er's MiU. {Bjidmv.Uc.) The Barker mill has attaineil celebrity ratlier as an interesting illus- tration of the principle of reaction or recoil than as a practically useful machine. It, however, has the essential features of the famous turbines and other reaction wheels. It consists of a vertical tuhe having an open fun- nel at top, and branching at its lower end into two horizontal radial tubes Fig. 562. Barker^s MiU. Each of these horizontal arms ha.s a round hole on one side of it, the two holes being opposite to each other ; and tlie verti- cal tube, being mounted on a spindle or axis, is kept full of water, flowing into tlie funnel at the top. The issue of water from the holes on opposite sides of the horizontal anus causes the machine to re- volve rapidly on its axis with a velocity nearly equal to that of the efflu- ent water, and with a force proportionate to the hydrostatic pressure due to the vertical column and to the area of the apertures ; for there is no solid surface at the apertures to receive the lateral pressure which acts with full force on the opposite side of the arm. .\ceording to Dr. Robinson, this unbalanced pres- sure is equal to the weight of a column having the oritice for its base, and double the depth of the water in the trunk for its hight. The machine has, for one hundred years, been a favorite subject with writers on d}-namics, and has been modified b\' mecbanician.s. De la Cour (1777) proposed to bring down a pipe from an elevated reseiToir, and, recuiTing its lower end upwardly, introduce the water into a short pipe with ten arms which revolved in a horizontal plane in the manner described. The revolving arms may be mounted on a horizon- tal axis so as to obtain the requisite dii'ection of mo- tion without iutermediate gearing. In ISil, Whitelaw obtained a patent for an im- provement, in which the hoiizontal arms assumed the form of the letter S. In this machine the water is discharged tangentially, the ca]iacity of the arms being greater as they approach tlie center of rota- tion, so as to obtain a quantity of water at every section of the arm inversely proportionate to its ve- locity at that section. The transverse sections of the arms are everywhere parallelograms of equal depth, but of width decreasing from the central ver- tical pipe to the jet at the outer extremity of the arm. A small machine of this descri|ition was con- structed, having a fall of 10 feet, the diameter of the circle described by the ends of the anns being 15 inches, and the aperture of each jet 2.4 inches in depth by .6 inches in width, the area of each orifice being 1.44 inches, the water expended was 38 cubic feet, the revolutions 387 per minute, and the efiect equal to 73.6 per cent of the power employed. Bark'ing. 1. Coloring sails, nets, cordage, etc., by an infusion or decoction of bark. 2. Strip|iing trees of bark for cork, dye, tanning material, or medicine. Bark'ing-axe. An axe of proportions and shape ad;iptt'il lor barking trees. Bark ing-tools. For remo\ing the bark of trees for tanning purjioses. Besides the axe or hatchet for slitting the bark longitudinally, and for cutting Fig. 563. Peelins-lrons. incisions around the trunk, which enable it to be removed in lengths, the barker requires pcclhuf- irons, which are thrust beneath the bark to loosen it. The operation is perfonned in spring, when the sap is abundant between the bark and the wood. Hi^ssing is not the exact equivalent of barking, as the former is a grinding or cutting action (usually). BARK-GRINDING MILL. O'^O. BARK-PLANING MACHINE. the latter a peeling. See Loudon's "Encyclopedia of Agriculture." Bark-griad'ing Mill. Weldon's Bark-.Vil/, 17y7, h:i.s a ciiiiicul iron drum A jirovided with teeth, and rotating in a easing JJ, tlie upper part of wliieh forms a Haring hopper. Tiie casing and its contained grinder are supported by a framing F, and motion is given to tlie cone by a belt running upon a drum on Fig. 664. Bark-Grinding Mitt. the upper end of the shaft D, whose lower end is supported in a step or ink. A screw below the step affords means for adjustment of the cone in the casing, the faces of the two being toothed, so as to effectually rasp the bark as it passes between their adjacent .surfaces. Bark'ing-mal'let. A short-handled mallet of hard wood. The face is three inches square, and the other end is sharpened to a peeii or wedge. Iron is a preferable material, and the same tool may he used for riiiginr/ the tree and splitting the envelope of bark longitudinally, so that it may be removcil by the pceli'itg- iron. Bark-mill. In Fig. 565 the bark is broken be- tween the Fig. 565. Bark-MiU. breaker D and teeth c, thence pass- ing between the rough- bottom sur- face of the hopper and till' rotating disk E. by which it is reduced to powder. Bark- om'e-ter. A hydrome- ter so grail- nateil as to determine the strength of oo7.e according to a given scale of proportions, water being zero. Bark Pa'per. Throughout Southeastern Asia and tlitcanii-a the IJruiissoiicsia papijrifcra, or paper mulberry, is a ctinnnon tree, and its bark is ca]iable, by soaking and beating, of assuming the appearance of tine linen. It may be bleached, dyed, andjirinted, and is a common material for dress in the islands of Oceauica. In Java and Sumatra it is the common material for writing upon. When solidified and liuruished, it resembles parchment. Manuscripts in Kuropeau museums attest its cpialitj'. The same bark made into a pulp is used in China and Japan for mid\iug jiaper. TIk' jirocesses adopted with bamboo and the mul- berry-bark are substantially similar after the reduc- tion of the raw material into a pulpy condition. The Chinese processes are as follows : — The paper-stuff being rinsed with water alone, or with water in which rice has been boiled, is brought to the state of pulp, and then transferred to a vat having on each side of it a drying-stove in the form of tlie ridge of a house ; that is, consisting of two sloping sides tonehing at top. These sides are cov- ered e.\ternally wdth a smooth coating of stucco, and a flue passes through the brickwork, so as to keep tlie whole of each side equally and moderately warm. A vat and a stove are placed alternately in tlie man- ufactory, so that there are two sides of two diHerent stoves adjacent to each vat. The workman dips his mold, which consists of a sieve-like bottom and a movalile raised frame surrounding it, into the vat, and then rai.ses it out again ; the water runs off' through the perfoi'ations in the bottom, and the pulpy paper-stuff' remains on its surface ; the frame is then removed, and the sieve is pressed bottom up- ward against the side of one of the stoves, so as to make the sheet of paper adhere to its surface and allow the sieve to be withdrawn. The water speed- ily evaporates by the warmth of the stove, and be- fore the paiier is quite dry it is brushed over on its outer surface with a size made of rice ; this also soon dries, and the paper is then stripped off in a fiiii.shed state, having one smooth surface, it being the prac- tice of the Chinese to write only on one side of the paper. While this is taking place, the molder has made another sheet, and pressed it against the side of the other stove, where it undergoes the operation of sizing and drying, as the other had done. If sheets of very large dimensions are to be made, the mold is snspendcil by a tackle and is managed by two men ; but in other respects the process is the same as that just described. Exceedingly beautiful paper is produced by this very simple method. Paper is made in India in much the same way and with nearly the same mate- rials ; but in the provinces north of the Ganges, and in Ne[ial, the common material is the bark of a sjie- cies of Daphne (laurel), which, like that of the paper- mulberry, consists almost wdiolly of fiber. Another mode adopted by the Chinese is to dip out the pulp in a mold made of strips of bulrushes in a frame. The sheets from the frames are piled on a table with intervening strips of reed, by which they may afterwards be lifted leaf by leaf. Each heap is pressed by boards and weights to express the water, and the following day, the leaves, being lifted singly, are laid f taiiiiliig. Bark-plan'ing Ma-chine'. A machine in which the layer of bark is suVijected to the action of consec- utive cutters, to separate the inner and outer layers. BARK-ROSSING MACHINE. 233 BAROGRAPH. The bark is passed beneath the rollei's with the rough side upjiennost, and the first cutter removes the iu- Fig. 566. / pif»: y^^ a SaTlc-Planing Machine, most bark, the second the inner portion of the outer bark, the extreme outer portion of tlie hark lieing discharged from the machine down the incline to the left. The dust removed by the respective cutters falls into separate receptacles. Bark-ross'ing Ma-chine'. A machine for re- moving the ros.% — that is, the rough, scaly portion from the outside of bark. The ross has a lesser pro- portion of tannin, and by its removal a steep of greater strength may be obtained and vat-room saved. Fig. 567. Bark-Rossing Machine. In the e.iample (Fig. 567), the machine consists of two pairs of toothed rollers which feed in the bark and thrust it against the stationary knife, whicli di^^des the ross from the liber, and the separated portions slide down diiferent inclines to special re- ceptacles. Bark-stove. iHorticuUiirc.) A bed of spent bark and soil, heateil by flues or steam-pipes, aided by a slow fermentation of its matenals. It is used to make a bottom heat for plants glowing in pots which are i^lunged therein. Bar-lathe. (Turning.) A lathe whose beam or shear consi-sts of a single bar on which tlie puppets or stocks and the rest are arranged. The bar is gen- erally of a tiiangular shape in cross section, one flat side downward. Bar'ley-chump'er. (Agrindturr .) A machine for bve^ikiiii,' the awn from the grain. {Prov. English.) A hii iti)i}'Utia-mni:hitui. Barley-fork. (AgricwUurc.) A fork specially adapted lor gathering up the unbound gavels of bar- ley or other grain, the stalks of which are too short to be readily made into sheaves. For this purpose it is pronded with an upright arrangement, as 13, at the base of the tines. In the example shown, the Fig. 568. Barley-Fork. tines and handle are attached to the metallic socket- head A, the whole being braced and supported by the bow B and biace G. Barley-huller. {Milling.) A machine for taking the hull or cuticle from the gi-ain of barley, making pot-biirlcy OT pearl -baric i/. The former has merely lost the cuticle, the latter has had a further amount of its substance removed by prolonging tlie jirocess for double the length of time. The process is anal- ogous to that of hominy-making. See HuLLlXG- M.\CinNE ; HOMINY-MACUIXE. Bar'ley-mill. {Milling.) A mill for decorti- cating barley ; luinging it to the condition known as^if»W-barley, the husk or the rind of the seed be- ing removed. There are several ways of acconi|ilish- ing this : 1. By the usual English barley-mill, — a stone roughened on its circumference, and revolv- ing in a metallic casing with holes like a gi'ater point- ing inward and upward. 2. By so regulating the distance between the ordi- nary runner and the bed-stone that the grain is not mashed, but merely the bian rubbed otf. Bar-loom. {Weaving.) A loom for weaving ribltoiis. Barm. (Brcicing.) The foam or froth rising from malt lii|unrs : yeast. Ear-mil 'li-ans._ (Fabric.) An old name for a kind of ln.>tian goods largely e.vported from England. Bar'na-cles. (Menage.) A noose attached to a stock or handle, and nipped arouml the upper lip of a horse. It is twisted so as to be somewhat painful, in order to give the command of the head to the per- son holding the same. It enables a man to hold the horse's head aloft to keep him from biting, oc- cupy his attention, and measurably prevent his kick- ing. Bar'o-graph. An instniment for recording auto- matically the variations of atmospheric pressure. 1 n Fig. 569 this is effected by means of \ ihotography. The operative and recording parts are inclosed in a case (which in the figure is sujiposed to be removed) which rests upon the horizontal slab, and entirely excludes the entrance of light excejit through the .■-lit C. ^ is a gas-burner, the light from which is thrown by the condenser £ over the top of the mer- curial column in the barometer-tulie J, and passing through the photograjihic lens D, is concentrated on a strip of sensitized paper wound around the cylin- der E, which is, by clockwork mechanism at F, made to revolve once in forty-eight hours. The image of that portion of the slit C above the mercurial column is thus caiised to fonn a continuous dark band of irregular width on the paper, liecoming narrower as the mercury rises, and widening as it descends in the tube, the width of the band indicat- ing not only the relative changes, but absolute bight of the barometer. A shutter operated by the clock- BAROMACROMETER. 234 BAROMETER. work cuts off the light for four minutes at the end of each second liour, leaviug a vertical white time- line on the paper. Fig. £69. Barograph, By the pxiian.sion of a zinc rod on each side of the baromcter-ttibe, in connection with a glas.s rod and lever, tln-rmonietric changes are made, and the true haiouK'tric changes, with corrections for temperature, are photographically recorded. BiiiKiKE's Self-Registering Barometer. Upon the colunni of mercury is a float carrying a mirror, on which a pencil of light is thrown. Tlie case is in- closed so as to exclude all other light, and the beam is i-ellei-ted by the mirror upon a traveling slip of paper indicating the extent and time of barometiic changes. Ba'ro-ina-croin'e-ter. An instrument for ascer- taining the weight and length of infants. Ba-rom'e-ter. (Meteorology.) An instrument for determining the weight or pressure of the atmos- phere. Invented by Torricelli alxjut the year 1643. Barometers are variously named from diH'erences in construction, mounting, fitting, etc. ; e. g. : — Aneroiil. Minimum barometer. Holosteric barometer. Mountain barometer. Hypsometer. Pediment barometer. Long-range barometer. Self-regi.stering barometer. Marine barometer. Sympiesometer. Maximum barometer. Wheel barometer. It is related that the pump-makers of Cosmo de Medici tried to raise water over 32 feet by means of a sucking pump, but failed to raise it over 31 feet. They applied to Galileo to resolve the dilliculty. He was unable to do it, but bade them accept the fact. His disci|)le Torricelli investigated the subject, and found that the force, whatever it was, raised a col- umn of mercury only 30 inches, which he judged to be the equivalent of the 31 feet of water, and hence deduced tliat the moving agent was not a nameless " horror of a vacuum," — a term which covered the ignorance of the real cause, — but was the pressure of the air upon the liquid ; and that this pres- sure was equal to about 15 pounds to the square inch. In 1647, Pascal showed practically that the hight of the mercurial colunm was affected by carrying the inverted tube to the top of an eminence. He made the experiment on a church - .steeple in Paris. To test the matter more completely, he wrote to his brother-in-law Perricr, who lived near the Puy de Dome, in Auvergne, to repeat the experiment on that mountain. "You see," he writes, "that if it happens that the bight of the mercury on the top of the hill be less than at the bottom (which I have many reasons to believe, though all those who have thought alxiut it are of a diffei'ent opinion), it will follow that the weight and pressure of the air are the sole cause of this suspension, and not the honor of a vaciuim ; since it is very certain that there is more air to weigh on it at the bottom than on the top, while we cannot say that natui"e "abhors a vacuum" at the foot of a mountain more than on its summit." On trying the experiment, JI. Perrier found a difference of three inches of mercury, "which," he says, "ravished us with ad- miration and astonishment." Claudio Bcriguardi, at Pisa, is said, how- ever, to have used the barometer for determination of bights five years earlier than this. It is certain that the varying weight of the atmosphere at differ- ent bights was known before Torricelli. Alhazcn the Saracen, A. D. 1100, was aware that the atmosplu're decreases in density with inci'ease of hight, and therefrom explained the fact that a ray of light entering it obliipiely follows a curvilinear path, which is concave towards the earth. He showed that a body will weigh ditl'erently in a rare and in a dense atmos)ilicre, and calculated that the hight of the atmosphere is nearly 58A miles, anticipating the discovery of Torricelli by several centuries. "The Book of the Balance of Wisdom," by AI Khazini (per- haps the same as Alhazen), gives a imniber of other luminous statements on mechanics. We take the liberty here of stating that he also wrote on the doc- trine of the progressive development of animal forms, l)ut did not reach the Darwinian conclusion. "Not," as he says, "that man was once a bull, and was then changed into an ass, and afterward into a horse, and after that into an ape, and finally became a man." This, he states, is only a misrepresentation by " common people " of what is really meant. There is 3'et some difference between the true the- ory of' progression anil the doctrine of the Vedas, the Institutes of Menu (contemporary with Elijah and Homer, and the teaching of Pythagoras, 040 B. 0. Rosalind, the charming, refers to the latter, apropos of finding the poetry tacked to the palm-tree : — "I never was so berhymed since Pythagoras' time that I was an Irish rat, which I can hardly remem- ber." — As you Like It. The pious Moslem prays that the All-Merciful will, in the Day of .Indgment, take pity on the soul of Abu- r-llailian, who first compiled a table of specific gravi- ties, the discovery of the great Archimedes thirteen BAROMETER. BAROMETER. Diameter of Depression. Diameter of Depression Tube. Inches. Indies. Tube. Inches Inches. .10 .Ii03 .40 .0153 .15 .0863 .45 .0112 .20 .0581 .50 .0083 .25 .0407 .60 .0044 .30 .0292 .70 .0023 .35 .0211 .80 .0012 hundred years before. Our own Draper desires to add a clause associating in this prayer the name of "Al/uizeti, wlio tirst traced tlie curvilinear path of a ray of light through the air." It would not be hard to tind good reason for associating the name of Dra- per with the illustrious two. The barometer in its ordinary form consists of a tube 34 inches in length, closed at the top, exhausted of air, and with its lower open end plunged in a cup of mercury which ascends in the tube by the pres- sure of the atmosphere. Changes in the weight of the atmosphere raise or lower the bight of the mer- curial column ; and a graduated scale alongside the tube, and embracing the range of motion, enables the reading of the variations. The wheel barometer has a recurved tube in which the mercury ascends and descends, thereby actuating a tloat which connects by a cord to the axis of an index-finger, which rotates on a graduated dial. It was contrived by Hooke in 1688, the year that the great Dutchman, Williamof Orange, cameto England. The pendent or marine barometer is suspended on gimbals, which enable it to maintain its verticality during the rolling and pitching motions of a ship, and has a contraction at the bottom of the tube to obviate oscillations of the mercury. It was intro- duced about the year 1698 - 1700. The invention of the aneroid barometer Fig. 570. is attributed to Conti, 1798, or to Vidi, 1804. Ill the aneroid barometer (which, as its name implies, has no liquid! the pres- sure of the atmosphere is exerted upon an elastic metallic diaphragm above a chamber partially exhausted of air. The (. motions of the diaphiagm, due to changes of pressure, are transferred to an index- finger which traverses in connection with a graduated .scale. See Aneroid. Barometers have been constructed in I which the tube and cistern were tilled ' with water instead of mercury. The great length of the column (nearly 34 feet at ordinary pressures) renders it extremely susceptible to slight atnios- d pherie changes ; so much so that even momentary fluctuations can be observed at times during storms : liut the difficul- ties in constructing and keeping in ad- justment a barometer of this kiml have prevented its coming into practical use. It would obviously be useless at temper- atures below 32" F. A standard barometer is one made with peculiar care, to serve as a standard of com- parison for less costly instruments of the kind, or for use in meteorological observa- tions, etc., where great accuracy and sus- ceptibility are desired. Tlie tube has in n some cases a bore of an inch or upward. a is the mercury-cup, b the adjusting 'SP^ screw, c the vernier, d the thermometer for data in making the corrections for . temperature. /^ In reading the barometer two correc- Siananrd tioiis are necessary : - Barometer. 1. For the cnpilldrifi/, or depression ol the mercury in the tube. 2. For the temperature. Pure mercury in a glass tube assumes a convex surface, and the convexity is gi-eatest in tubes of small diameter. The following is Ivory's scale, giving the correc- tions for tubes of dift'erent diameters : — In siphon barometers, as the depression is equal in each leg of the tube, no correction is necessary. The correction for tempierature involves the con- sideration of the expansion of the mercury and also of the graduated scale. The latter, being minute, is, however, generally disregarded, and that of the mercury being .0001001 for each degree Fahrenheit, it has been usual to subtract from the reading -rrrfW of the observed altitude for every degree of Fahren- heit above 32°. An example of the correction wiU stand thus : — Thermometer, 54°. Barometer, 30 inches. (54 — 32) X 30 X .0001 = .066, to be subtracted from 30 inches. Result, 29.934 inches. Calculated correction tables are publi-shed. The holosteric barometer is one in which a fluid is dispensed with. The usual form is the Aneroid (which see). The Vidi aneroid has a metallic dia- phragm ; the Bourdon aneroid has a bent tube capa- ble of flexion. See Bourdon Barometer. A form of holosteric barometer is constructed on a principle similar to that of the hygronutric balance. Its action depends on the did'erent specific gravities Fig. 571. ^ Balance Barometer. of a short metallic arm a and a long and bulky wooden arm b, lialanced on a pivot c at then- com- mon center of gravity ; the long wooden arm, dis- placing a greater bulk of air in proportion to its weight than the other, is depressed by the rarifica- tion and elevated by the condensation of the atmos- phere, causing the two arms to oscillate about the sustaining pivot, the variations being shown by a scale d, to which the longer ami points. From a manual compiled by liear-Admiral Fitzroy of the English navy, and ]iublished by the Board of Trade, the following is condensed : — The barometer shows changes in the weight of the atmosphere, if any occur. Changes in the level of the mercury are more em- phatic than actual elevation. If the mercury, standing relatively high, should fall, it presages a change, but not so great a one as if the mercui-y stood lower and fell to the same ex- tent. The converse is also true. The barometer foretells coming weather rather than indicates the present. The longer the inter- val between the sign and the change, the longer said altered weather will last. The converse is also true. BAROMETER-GAGE. 236 BAROIIETROGRAPH. Tlie liaronu'ti-r being at medium hight and rising, the theiinoniBter falling indicates dry weather. The converse ; barometer medium and falling, thermom- eter rising, rain ; thermometer falling, snow. The rising or falling condition of the mercury may be observed upon its upper surface ; convex if rising, concave if falling. Fluttering changes indicate unsettled weather ; slow movements the contrary. Rapid and continued fall is a sign of a storm, the wind being from the north if the barometer is low (for the season), and from the south if the thermometer is high. Tluve causes allect a barometer ; — 1. Tlie direction of the wind. 2. The moisture of the air. 3 The force of the wind. AVhen they act separately they act less strongly, and when coincidently the change in the barometer is greatest. Ba-rom'e-ter-gage. ISIeam-Engiiic.) An at- tachment to a boiler, condenser, or other chamber, wliieli indicates the state of the vacuum. When a boiler is allowed to cool, the steam con- denses, and a more or less perfect vacuum is formed therein, subjecting the boiler to heavy external at- mospheric pressure. This ciuitingency is usually met by an inlet safety-valve, called a W(cin(;«-valve. When a condenser is in operation, it is desirable to know the condition of the vacuum, as a test of the efhiieney of the air-pump. When a receiver is partially exhausted for expeii- mental purposes, it is desirable to obtain an indica- tion of the tenuity of the contained air. The Baromc- Fig. 572 tcr-gngehnheni glasstubert,one end being plunged in a cis- tern of mercury i, and the other enil c connect- ing with a steam- boiler, condens- er, or tank, as the ease may be. When the jet of water con- denses the steam in the condenser, a partial vacuum is formed, and the external at- mosphere is in excess of the internal pres- sure, so that the mercury is caused to as- cend the tube. Another form 1 an inverted siphon, themer- cury being con- tained in the bend il. as in the Sleam-Pivssurc Gftfim. Bar-o-met'ri-cal A-e'ri-om'e-ter. (Meteorol- ocjy.) An inverted siplion used for approximately determining the relative speoitie gravities of immis- cible fluids, as oil and water, or water and mercury. For instance, if mercury be poured in one limb and water into the other, and the stop-coek at c be turned so as to establish a communication between them, it will be found that an inch of mercury in one limb Fig. 673. Barometer- Gages. Bttrometrical Aeriomfter. will balance 13^ inches of water in the other, showing the relative speciKe gravities of the two fluids to be as 13^ to one. Bar-o-met'ro-graph. (Meteorol- oijij.) An instrunji-iit liy which the va- riations of atmo.splierie pressure are automatically recorded on a sheet of papei'. Nai'IEK .s instrument, patented in ISiS, is intended to mark the varia- tions of atmospheric pressure during an- entire period of 24 hours. Con- nected with the barometer-tube is a vertical .spindle carrying a card which lias on its surface a number of radial lines anil concentric circles ; the radial lines represent fractions of inches, and the concentric circles represent por- tions of time. Aliove the card is a lever carrying a vertical iiricker, which is made to rise and fall at certain regular intervals of time, and to travel from the inner concentric circle to the outer one once in 24 hours. On the vertical spindle, and underneath the card, is fastened a grooved wheel, around which is passed a cord, while the other end is made fast to a tloat resting upon a column of mercury in a tube. The card has a fixed point repiesenting 29.5 inches, which, at the commencement, is placed underneath the priekei-. As the column of mercury rises or falls by the varying pressuie of the atmosphere, the jirinted card will tiavel to the left or the right accordingly ; and the variation of hight will be indicated by tlie distance of the punctureil lines from the starting-point on either side. A self-registering barometer, recently invented in France, is shown in the accompanying cut. The records are continuous and comparable, and are pro- duced by the variations of an aueroid. The pressure of the atn!os])here affects four metallic boxes, as in the ordinary aneroid, having their upper and under faces undulated ; a vacuum is made in each of them separately, and they are attached together in one series, so that for an equivalent variation of pressure the movement is four times greater than it is for one box only. A very strong flat steel spring R acts upon the barometric boxes in an opposite direction to the atinos]jheric jjressure. This spring controls the indicating lever L L by means of a connecting piece at the point B: this connector receives the action from tlie extremity of the spring, and com- nuinicates it to the lever i i at a point very close to its axis, from whence it follows that a consider- able multiplication of movements is the result. The indications of the movements of the lever are registered in the following manner : A cylinder C is revolved by the regular movement of an ordinary pendulum timepiece ; it makes a complete revolution in one week, and carries a glazed paper which has been smoked black by means of a candle. At the extremity of the lever is a very fine spring, pointed at the end, which rests upon the cylimler and traces a white line upon the black ground. At the end of each week the paper is changed for a fresh one, the record on the old one being protected by a coat of varnish. The action of the self-registering and printing barometer, invented by Professor Hough of the Al- bany Observatory, depends upon the making and breaking of an electric circuit by the rising and fall- ing of the mercury, for the communication of impulses to electro-magnets, which unlock a train of clock- work so devised as not only to describe a constant curve upon a piece of paper, representing the hight BAROSCOPE. 237 BARREL. Fig. 574. French Baromelrograph. of the column at any time of day and night for many davs in succession, but also to luint upon pages, which may be subsequently bound, the hights of the column as often as may be desired, thus making a printed record. The barometer employed hasa siphon tube. Bar'o-scope. {Meteorologi/.) An instrament which indicates the variations in weight of the at- mosphere without indicating its absolute pressure. A weather-glass. Of this class are the iustrunients called proguosticators, or storm -glasses, consisting of a tube containing a clear liquid in which a Hoccu- lent substance floats, rising and falling with varia- tions in the weight of the atmosjiheric column, and thus indicating the kind of weather which may be expected. Somewliat allied to these are instnmients in which a flocculent substance i< suspended in a menstruum ; the assumption of a milky appearance by tlie material indicates an excess of moisture in the air, and prog- nosticates rain. The wheel barometer of Hooke is also a baroscope, as its changes and indications are made visible by means of a float in the mei-cury, whose counterbal- anced suspension-string moves a hand on an index- circle. Ba-rouche'. {Vehicle.) A four-wheeled carriage, having a falling top. It has two seats inside, ar- ranged so that four persons can sit two facing other two, the seat for the driver being outside. Bar-pump. (HiidrauUcs. ) A small boat-pump for i-aising water, oil, etc., from large casks. Prob- ablv from Bnrr-pump. See B.^re-it.mp. Bar-quan-tine'. [Xautical.) A three-masted vessel, scpiare-rigged on tile forenia.st, and fore-and- aft rigged nn the main and mizzen. Commonly found on the Northern lakes. Also spelt barkaiUbu. Barque. (Xnulknl.) A three-masted vessel whose lore and main masts are squarc-rUiged, like those of a ship, and whose mizzen is forc-and-afl rigged, like a schooner. Bar'ra-can. (Fabric.) A thick, strong stuff', known by this and similar names in most of the languages of Europe and Western Asia. It is made in AiTOeuia and Persia of camel's hair, like cnmlel, whose name also indicates that its material is deiived from the same animal. The name has been presen'ed, while the fabric has been made of other materials, — wool, flax, and cotton. It was during the wool stage that the memorable Falstaff' celebrated his achievements : ' ' Four rogues in buckram (barmcan) set at me." An article called barracan is yet used in Europe, and in some countries is mainly cotton, resem- bling/«.s^i'«is. The old Roman toga was commonly made of this material. Barrack. (Engineering.) A temporary build- ing for quartering soldiere or for workmen. Per- manent buildings, also, designed exclusively for occupancy by soldiers, are geuerally so called. Also a structure erected for sheltering the workmen where Avork is progiessing in an isolated position, to which access is at times difficult or impossible, on account of the state of the tide or weather. Of this class were the Fig. 575. • Barrack on Skfnyvore Rock. temporar}- dwellings erected by the Stevensons on the Bell Rock inthe Frith of Forth, and on the Skerry vore Rocks, about 12 miles AV. S. AV. of the island of Tyree, Argyllshire, Scotland, for the pro- tection of the men, provisions, tools, and a portion of the materials. Bar'rage. 1. (/"aftnc) A Normandy fabric made of linen interwoven with worsted flowers. 2. (Hydraulic Enijinecriiig.) .Bfjrra^c is a French word, signifying, in general, an artificial obstruction placed in a -water-course in older to obtain an in- creased depth for na%ngation, irrigation, or other puqioses. Barrage-fixe is a permanent dam of ma- soniT. Barrnge-mobih is a dam having a sluice by which the flow of water may be regulated. Bar'ras. (Fabric.) A kind of packing-cloth. Bar'rel. A word applied to hollow cylindrical objects, such as — 1. (Pump.) The piston-chamber of a pump. 2. A cask for containing liquids, usually having a capacity of from 30 to 45 gallons. A cask for certain kinds of provisions, — flour, fruits, vegetables, etc., — holding 196 pounds of flour (American custom), or about 2^ bushels of fniit, varying according to the customai-y practice in re- gard to striking or heaping the measure. BARREL. 238 BARREL-FILLER. Dickenson''s Wrought-Iroil Barret. A iMeiV.sure of ear-corn in the Southern States, shi'lliuj,' 2h bushels. Tlie D1CKEN.S0N Patent Wrought-Iron Barrels, usi'd in the British navy, have a cylimli-ical form, with a soldered seam. An irou hoop b is riveted to eaeh end. This hoop has a rabbet, and the thickest part is riveted to the drum a, wliile the other por- tion forms a recess with the side of the drum for the reception of the Fig. B76. tiauge of the head c, whicli is made by bend- ing the periph- ery of the circu- lar iron plateata rightaugletoits pUuR". A pack- ing of greased liemp-bands is placed in the i recess, the Hange of the head driven in, and then the edge of the iron hoop is turned over against the bottom head, making an air and water-tight joint. This is for the bottom head. The upper head is removable without damage to the package. The upper portion of the hoop is not flattened down as at the other end of the barrel, but a number of latch- bolts are pivoted to the cover, and catch into open- ings in the side of the hoop. Tlie metal is coated inside and out with canvas saturated with a composition of caoutchouc, 8 ; black resin, 4 ; Venice turpentine, 1. This is digested, spread on the cloth, and the lat- ter is then run between rollers. 3. (Horo'ogij.) a. The hollow cylinder or case containing the mainspriiuj of a watch, or .spring clock (a. Fig. 577). It Fig. 577. is connected by a chain with the/iwcc, and by the \vinding of the latter the chain passes from the' barrel, and the viainspring Barrels. is wound. See Fusee. When the/fKcc cannot be introduced into a watch, owing to the flatness of the movemciU, the first wheel is attached to the barrel, which is then called a gyiiiy-barrcl {b. Fig. 577). Slop-works are attached to regulate the action of the spring ; that is, to prevent its being wound too tight or running down too far, using thi' middle power of the spi-ing and rejecting its highest and lowest powers. This is particularly necessary in watches destitute of the fusee. See- Stop-work. b. The chamber of a spring-balance. 4. [Fire-arms.) The tube of a gun from which the projectile is discharged. 5. (J/itsjc.) The cylinder studded with pins by which the keys of a musical instrument are moved. 6. (Metallurgii.) A cylindrical vessel moring on an axis, for amalgamating, polishing (tumbling-box), or making gunpowder. In the latter case it is par- tially filled with bell-metal balls, and is called a roll iiig-barrel. 7. (MaiUieal.) a. The main piece of a capstan, between the whelps and the pawl-rim. b. The cylinder around which the tiller-ropes are wound. 8. The sonorous portion of a bell, which is attached by the remaining portion, the canon or ear, to the suspensory arrangements. y. (Pulleij.) The cylindrical portion of a drum or pulley on which the band laps. 10. {Steam-Engine.) The cylindrical portion of the locomotive boiler extending from the lire-bo.x to the smoke-box. Bar'rel-drain. A cylindrical drain. Bar'rel-dry'er. A device ibr drying barrels after being coopered or washed, before refilling. Fig. 578. Barrel- Dryer, The view (Fig. 578) is sectional, and shows two tiers of main steam-pipes with vertical branch-pipes extending upwardly through the bung-holes into the interiors of the casks. Bar'rel-fill'er. (Hydnndics.) A device for filling casks, provided with an automatic arrangement for cutting off the supply of liijuid in time to prevent Fig. B79. Barrel-Filling Apparatta. overflow, or calling attention to the fact that the vessel is about full. In one form, the rising of the liquid in the^barrel is the means of stopping the flow. In Fig. 579, the tube A' B is jointed at I). The end bearing the float BARREI^FILLING GAGE. 239 BARREI^ROLLER. K is inserted into the barrel to lie filled, and, as the float rises, it, through the medium of the rod L and jointed lever J/ N 0, releases the detent i/, allow- ing a spring to foree up the rod g and depress the rod e, closing the vah'e E and cutting oft' the supply- As the projecting spout £ is lightened by the ab- sence of the liquid, the counterpoise weight T lifts it clear of the bung-hole. In another form, the liquid flows through a stop- cock to enter the baiTel ; when the latter is full, the liquid overflows into a chamber in which a float rises and operates a lever to close the stop-cock. In another form, a-s tlie liquid rises and closes the air-exit, the air condensed in the upper part of the barrel passes through a duct in the faucet, and by pressure on a diaphragm operates a lever which closes the supply. In some cases the elevation of the water-level oper- ates a wliistle, in another rings a bell. The ascend- ing float, however, is the usual operative feature of the barrel-filler. Bar'rel-fiU'ing Gage. {Hydraidies.) An auto- matic indicator, used in connection with a faucet, to announce when the barrel is about full, so that the supply may be stopped. Some gages merely show the hight of the liquid in the barrel ; others give an alann when it attains a certain hight ; others cut oS' the supply. See B.^rhel-filler. Bax'rel-head Cut'ter. (Coopering.) a. A tool for rounding and c|iamfering barrel-heads. The Fig. 5S0. II 1 yJK'.'l II \ I III Barrel Head Cutter. pivot c is stuck into the center of the head, and the tool rotated by the handle H. The angular cutter Fig. oSl. Enrr^UHender Fin adjustable on the shank B of the tool, according to the radius of the barrel-head. b. A machine for effecting tlie same purpose. In the example the blank is placed between the clamp- ing disks, and the frame turned so as to bring the blank in contact with the disked saw ; this move- ment also brings the bevel-wheel upon the arbor of the clamping-disks in connection with its motive- wheel upon the saw-shaft. The frame is duplicated, so that while one blank is being operated on, another may be clamped in position. Bar'rel-head Hold'er. (Coopering.) A clamp con^^isting of a pair of jaws for holding barrel-heads in i>osition wide being trimmed around the edges. Bar'rel-hoop'ing Ma-chine'. {Coopering.) A machine for setting the hoops on a barrel. A circu- lar ring has pendent drivers, and is reciprocated by a rack-bar and pinion. The assembled staves are placed in upright position, and the hoops driven thereon by the downward motion of the drivers. Bar'rei-loom. (jreaving.) a. A loom in which a barrel, usually a square prism, receives the perfo- rated cards which determine the figures. A jacquard loom. b. One used for wearing figured fabrics ; the rising and falling of the heddles which govern the wai-ps being accomplished through the agency of pins on the revolving barrel. Bar'rel-mak'ing Ma-chine'. {Coopering.) A machine or series of machines by which some prin- cipal part of the process of, or the series of processes in, making barrels is performed. Brown's English Patent, 1825, embraces the foU lowing series of devices : — 1. A circular saw, with a bench and slide-rest, having an adjustable guide consisting of a flexible bar, which is bent to the curve desired for the edge of the stave. A piece of wood of proper dimensions is clamped to the slide-rest, which is advanced by hand along the guide and presented to the circular saw, which gives the proper cuitc to the edge of the stave. 2. An apparatus with cutters, attached to a re- volving standard, by means of which the staves, secured by temporary hoops, are crozed. 3. An apparatus somewhat similar to the above, in which the straight pieces of wood for forming the heads are held together, cut to the circular figure required, and beveled. 4. A machine in which the cask, after having been assembled and headed up by hand in the usual way, is revolved, while a cutting tool is made to traverse along its exterior, forming a smooth surface. The arrangement of the machineiy at Glen's Falls, N. Y., consists of three machines : the first for cut- ting the staves to the required length, finishing the heads, and making the croze ; the second jointijig the staves in packs ; the third forn)ing the heads. Bar'rel-or'gan. [Music.) An instrument in which the notes are sounded by means of pins or staples, arranged as to time and place on the surface of a cylinder which is rotated by hand. See Haxd- ORGAV. Bar'rel-pen. A steel pen which has a split cylin- drical shank, adapting it to slip upon a round holder. Bar'rel-pro'cess. A mode of extracting precious metals from ores. See Am.\lgamator. Bar'rel-roll'er. A device for clamping the ends of a barrel, and manipulating it so as to allow it to turn freely when rolled along on its bilge. A pair of handles of a convenient size are crossed, and pivoted at the point of crossing like a pair of scissors. The opposite ends of the handles are each BARREL-SCREW. 240 BARROW-PUMP. provided with a disk of a diameter somewhat less than that of the common barrel-head. Each disk _. ,„„ is pivoted at its Fig 682. ' , .. centerto Its sup- porting arm and so as to revolve freely. The handles are of such form that the disks may be appliud, one at each end of a barrel, and pressed closely against it, whereupon the barrel may be Barrel- Roller. ^^^i^^y ,,oii;.j Bar'reVsaw. (Coopering.) A cylindrical saw for sawing staves, etc., to a curved form They are afterward" bent to the required longitudinal curve. The saw is mounted on a table, and means are pro- vided for keeping it up to the work and retracting it therefrom. Fig. B83. Fig. 584. Barrel-Saw. Cylindrical saws are also used for sawing chair- backs, brush-backs, and fellies. Bar'rel-screw. (Shiinoriijhling. ) A form of screw-jack used in a shipwriglit's yard to move heavv tini'icr-i or assist in launcliing. Bar'rel-3et'ter. (Gmi-inal-ing.) A cylindrical mandrel trsed by aiinorers for straightening the bar- rel of a liie-ann and in truiiuj the bore or exterior surface. Bar'rel-vault {^fasonr;/.) A cylindrical vault. Bar'rel-vise. (Oun-smithbui.) A bench-vise, having a lonu'it\idiiial groove in its jaws to tit it for the reception of a gun-barrel, which may be protected from direct contact of the jaws of the vis;i by sheet-lead or other soft metal cheeks. Bar'rel-wash'er. {Brewing.) A ma- chine in wliich casks are cleansed after use, preparatory to refilling. In one example, the barrels are clamped in the frames tliat turn on pivots in jour- nals in an iron frame. The barrels are arranged at an angle to their line of rota- tion by a clamp with a corrugated surface that curves to suit the bilge of the bar- rel. To vary the angle to the plane of rotation of ail the barrels simultaneously, the clas|)S are mounted in circular guide- Wfiys on the chimping rails, so that they may vibrate in arcs of which the axis of rotation of the frame forms the center. This causes a swashing motion of the water endways of the barrel, by which iti interior is cleansed. Barrel- Washer. Bar-ret-tee3'. {Fabric.) A kind of plain silk. Bar'rier. (Fortification. ) An obstacle, such as a )ialisade or stockade, for defending an entrance to a fortification. It is provided with a central gate formed of strong upright timbeis, connected by transverse beams at top and bottom and a diagonal brace. Bar'rier-gate. {Fortification.) A gate closing the entiam.'c through a stockade or barrier. Bar'rOTW. 1. (Mining.) A heap of oiWc, or rub- bish. 2. {Vehicle.) A light carriage for transporting articles, moved by hand. See Hand-bailuow and Wheklbaim-.ow. 3. In salt-works, a wicker case in which the salt is put to drain. Bar'roTW-pump. {Hydraulics.) A combined suc- tion and Ibrce jiump, rendered portable by being mounted on a two-wlieeled barrow, and adapted for agricultural and fire-engine purposes. In the illustration .sliown, the pump is double- Fig. 585. BaTTO\c-Pitmp. acting, and is worked by the lever n, which pro- jects over and between the handles of the barrow. h is the suction-hose ; d, discharge-nozzle ; e, air- chamber ; g, cylinder. BAR-SHARE PLOW. 241 BASCULE BRIDGE. Bar-share Plow. {Agriculture.) One having a bar extending backward from the I'o'nt of tlie share. Used in tending crops, laying out corn-rows, etc. Bar-shear. (Metal-working.) A machine for cutting metallic Ijars. It consists of a very strong tig. 566. Sar-Sh-ar. frame, having a fixed lower blade e and a vertically reciprocating upper blade d, between which the bar is sheared, a is the fly- wheel, b the main gear-wheel on the axis of the cam (hidden in the interior of the casing), which works the tail of the lever c and reciprocates the jaw d. See Bar- cutter. Bar-shoe. {Farrienj.) A horseshoe which is not open at the heel, but is continued round at the rear. It is used with horses which are liable to contrac- tion of the heel, to spread that part of the foot. Bar-shot (Ordnance.) A projectile formerly used, consisting of two cannon- balls, or half-balls, united by a bar of iron, and employed for severing the rigging of vessels, as w"ell as for field and fort artillery. Shot used in proving ordnance may be considered as belonging to this class, con- sisting, as they do, of a bar with hemi- spherical ends, weighing twice or three times that of the solid shot used in service. Bar-ti-zau'. (Fortification.) The overhanging tunets of a battlement. Bar'ut-ine. (Fabric.) A kind of Persian silk. Ba-saltlng. A process for utilizing the scoria; of blast-furnaces for making paving and building blocks. Ba-sane'. (Leather.) French tanned sheep-skins for bookbinding. Batcsin. Bas'cule. (Fr. sec-saw.) A form of bailing-scoop used by Perronet at the Bridge of Orleans was worked by 20 men, 10 at each end. 600 motions were given to it per hour, and at each motion 4 cubic feet of water were raised 3 feet high ; 2, 400 cubic feet per hour. It consists of a pair of scoops re a on a .single frame, which is pivoted to oscillate upon bearings on the summit of posts b, secured to a frame planted on the bottom of the river, pond, or inclosure to be dra ined See Bailing-scoop. 16 Fig. 587 PerroneCs Bascule. Bas'cule Bridge. A counterpoise drawbridge which oscillates in a vertical plane; the inner por- tion descends into a pit, while the outer ascends and closes the gateway. A bridge which has its track simply hinged to the edge of the scarp or curbing, and which is lifted by weight or windlass, is classed as a Liftixg-ehidge (which see). The bascule has an inner portion of roadway, which acts as a counterpoise to the portion which projects over the water-way. The inner por- tion ilescends into a dry well when the bridge is Fig. 688 Bascule at Brussels. lifted into a vertical position, the outer portion clos- ing the opening in the wall outside of the portcullis, if there be one. This form of bridge was not uncom- mon in the castles of the feudal times, when the rich owned the poor, and learning had no refuge but in the Church. Fig. 689 Bascule Neu/ Brisark. BASE. 242 BASIX-FAUCET. A bascule bridge at Brussels, called a bnlancinij- bridgc, lias an overweighed land end, so that it as- sumes the vertical when a chock beneath its inner end is lemoved. The land end works iu a (|uad- rantal pit lined with iron. The strut that supports the land end is footed upon a set-ott' in the masonry, and a swinging strut limits the depression of the bridge at its outer end. When tilted, the bridge is held in position by a rack and jiinion. Instead of the heavily counter-weighted platform, a pendent weight, chain, and jiulleys may act ujion a vertical arm to raise and lower the platform, which oscillates upon a horizontal a.xis. Base. 1. {^Ordnance.) The ],rotuberant rear por- tion of a gun, between the knob of the cascabel and the biisc-riiu/. The base is the middle member of the ca^scabel when the piece has a base-ring and knob. In the simpli- city of modern pieces, many mere ornaments and extraneous matters are omitted. The base is always present, forming the rounded contour at the rear of the breech. 2. (Carpentry.) The skirting-board next to the floor of a room. 3. (Surveiiiiuj.) The main line of a .survey, ascer- tained by actual measurement, upon which the sub- sequent trigonometrical operations are founded. 4. (Arehik'clure.) The lower part of a structure : of a building it may constitute a basement ; of a col- umn it may consist of basc-violdings and })linth. 5. (Forlificalion.) The line connecting the salient angles of two bastions. 6. {Dentistry.) A foundation resting immediately upon the gums, on or into which the artificial teeth are placed. Baae-burn'ing Fur'nace. A furnace or stove in which the fuel is Fig. 690. H