I ■ WORKS ON FOUNDING. PUBLISHED BY JOHN WILEY & SONS. THE IRON FOUNDER. By Simpson Bollancl, Esq,, Practical Iron Founder. The contents comprise Core-Making, Loam Moulding, Dry Sand Moulding, Green Sand Moulding, with Miscellaneous Items, Recipes, Tables, etc., etc. 400 pp., 12mo, cloth, $2.50 "THE IRON FOUNDER" SUPPLEMENT. A Complete Illustrated Exposition of the Art of Casting in Iron. Comprising the Erection and Management of Cupolas, Reverberatory Furnaces, Blowers, Dams, Ladles, etc.; Mixing Cast Iron; Founding of Chilled Car Wheels; Malleable Iron Castings ; Foundry Equipments and Appliances ; Gear Mould- ing-Machines; Moulding Machines ; Burning, Chilling, Softening ; Annealing; Pouring and Feeding ; Foundry Materials ; Advanced Moulding; Measurement of Castings ; Wrought Iron, Steel, etc. ; also, The Founding of Statues ; The Art of Taking Casts; Pattern Modelling; Useful Formulas and Tables. By Simpson Bolland, Practical Moulder and Manager of Foundries; Author of "The Iron Founder," etc. Illustrated with over Two Hundred Engravings. 400 pages 12mo, cloth, $2.50 ENCYCLOPEDIA OF FOUNDING AND DICTIONARY OF FOUNDRY TERMS USED IN THE PRACTICE OF MOULDING. By Simpson Bolland. 12mo, cloth (in preparation). AMERICAN FOUNDRY PRACTICE. Treating of Loam, Dry Sand and Green Sand Moulding, and Containing a Practical Treatise upon the Management of Cupolas, and the Melting of Iron. By Thomas D. West, Practical Iron Moulder and Foundry Foreman. Fully Illustrated. Ninth edition 12mo, cloth, $2.50 MOULDER'S TEXT-BOOK, BEING PART II. OF AMERICAN FOUNDRY PRACTICE. A Practical Treatise on Moulding, discussing the question of Economy in Casting, and the arrangement of a Foundry in regard to rapid work. Treating of Cupolas, Methods of Firing, Best Means of Securing Perfect and Sound Castings, etc., being a continuation of Vol. I. on this subject, and dealing with a class of work requiring more skill and greater care. By Thomas D. West. With numerous illustrations. Seventh edition 12mo, cloth, $2.50 MACHINERY PATTERN MAKING. A Discussion of Methods, including Marking and Recording Patterns, Printing Press, Slice Valve and Corliss Cylinders ; How to Cast Journal-boxes on Frames, Differential Pulleys, Fly-wheels, Engine Frames, Spur, Bevel and Worm Gears, Key Heads for Motion Rods, Elbows and Tee Pipes, Sweeping Straight and Conical Grooved Winding Drums, Large Sheaves with Wrought and Cast- iron Arms, 128 full-size Profiles of Gear Teeth of different pitches for Gears of 14 to 800 Teeth, with a Table showing at a glance the required diameter of Gear for a given number of teeth and pitch, Double Beat, Governor, and Plug Valves, Screw Propellor, a chapter on items for Pattern Makers, besides a number of valuable and useful Tables, etc., etc. 417 illustrations. By P. S. Dingey, Foreman Pattern Maker and Draughtsman 12mo, cloth, $2.00 "A neat little work that should be not only in the hands of every pattern maker, but read by every foundry foreman and proprietor of foundries doing machinery work." —Machinery Moulder's Journal. THE ENCYCLOPEDIA OE FOUNDING AND USED IN THE PEAOTICE OF MOULDING. TOGETHER WITH A DESCRIPTION OF THE TOOLS, MECHANICAL APPLI- ANCES, MATERIALS, AND METHODS EMPLOYED TO PRODUCE CASTINGS IN ALL THE USEFUL METALS AND THEIR ALLOTS, INCLUDING BRASS, BRONZE, STEEL, BELL, IRON, AND TYPE FOUNDING ; WITH MANY ORIGINAL MIXTURES OF RECOG- NIZED VALUE IN THE MECHANIC ARTS. ALSO ALUMINUM, PLATING, GILDING, SILVERING, DIPPING, LACQUERING, STAINING, BRONZING, TINNING, GALVANIZING, BRITANNIA- WARE, GERMAN-SILVER, NICKEL, SOLDERING, BRAZ- ING, ORES, SMELTING, REFINING, ASSAYING, ETC. SIMPSON BOLLAND, Practical Moulder and Manager of Foundries ; & LS ^ / ' Author of "The Iron Founder," "The Iron Founder Supplement,'''' etc. FIRST EDITION. FIRST THOUSAND. NEW YORK : JOHN WILEY & SONS, 53 East Tenth Street. 1894. Q^' > Copyright, 1894, BY Simpson Bolland. P PEEFACE. The ordinary dictionaries and encyclopaedias of general literature, and even those of the arts and sciences, contain but few notices of foundry terms; and where these do occur, the explanations are in many instances very meagre, and often wide of the mark, showing either a limited knowledge of the subjects treated or a want of appreciation of their importance to the practical moulder, as well as to others who need information on such topics. If this work helps to supply this deficiency the author will be well rewarded. Opportunity has been taken throughout its pages to introduce words which, until lately, had apparently no connection with the founder's art, and in the explanation of which special care has been observed to explain their meaning by such methods of illustration as will bring them into direct association with the whole science of founding particularly. It is with this view that names of minerals, metals, and chemicals have been inserted, the author believing that, remote as some of them may appear, they all have a bearing, direct or indirect, upon the general business of founding at this day, and should receive at least as much attention as has been accorded them. iii IV PREFACE. The treatment of brass founding, etc., is a reflex of the author's life-experience largely; and whenever it has been thought proper to consult the chemist, metallurgist, or mechanical engineer, the best authorities on these subjects have been chosen. Simpson" Bollastd. New York, May, 1894. THE ENCYCLOPEDIA OF POUNDING. -A-, Agate. Acetate. — A salt formed by the union of acetic acid with a salifiable base ; as, the acetate of copper, the acetate of silver, etc. Acetic Acid. — If vinous fermentation is not checked in due time, it passes at once to the stage of acetous fer- mentation, and the liquid becomes sour ; oxygen is ab- sorbed, and the alcohol converted into vinegar, or acetic acid. See Pitch. Adhesion. — This is a force which unites dissimilar bodies, and is exerted between substances of all kinds. The sticking of blackening to mould -surfaces, loam to bricks, glue to wood, etc., are well-known examples of adhesive force. See Agglutination. Agate. — This stone is an aggregate of siliceous sub- stances, the character and color of which is maintained in the mass. Agate is composed of chalcedony, quartz, ame- thyst, carnelian, jasper, common opal, etc., with all their varying colors. Its hardness and beauty have brought it into great demand both for useful and ornamental pur- poses. See Stone ; Precious Stones. Agglutination. 2 Air. Agglutination. — The act of uniting, by means of some viscous substance, as glue, molasses, etc., which causes an adhesion or sticking together of parts or particles which of themselves have no adhesiveness. Silica-sand with molasses ; the various free-sands for cores with glue, flour, rosin, etc., are familiar examples of agglutinants, and their usefulness in foundry practice. See Coke-sand ; Flour ; Glue. Air. — The thin, gaseous medium which surrounds the earth. Air, like all other forms of matter, has weight, as may be proved by exhausting the air from a light flask aud, after counterpoising at the balance, allowing the air to enter, when it will at once descend. One hundred cubic inchs of air weighs about 30^ grains, or 828 times lighter than water. Particles of air, like other elastic fluids, mutually repel each other, and would therefore spread out into space, and become exceedingly rare if it were not for the attraction of the earth. Consequently about 50 miles is as far as it extends from the surface, and it thus obtains weight. This weight, or pressure of the air at sea-level is 15 pounds on every square inch, which is called an atmosphere; 60 pounds would be four atmos- pheres, etc. Several gases enter into the mixture of atmospheric air ; oxygen and nitrogen constituting its bulk, however, with a small proportion of carbonic acid and watery vapor, etc. Its average composition by volume is oxygen 20.81, and nitrogen 79.19 in 10,000 parts; or, by weight, oxygen 23.01, and nitrogen 76.99. The atmosphere is a mechanical mixture, not a chemi- cal compound ; it constituents being mixed or diffused throughout each other. A candle will burn in an artificial mixture of nitrogen 4, oxygen 1, and animals will breathe in it, as in the atmosphere. See Thermometer. Air-pump 3 Alcohol. As a technical term in the foundry, air means any or all of the gases that generate during the processes of casting, which, if not suitably disposed of by venting, become a source of annoyance and danger to the moulder. For more definite information and instruction regarding the latter, see Venting. Air-pump. — A pneumatic machine for exhausting air from a tight vessel, and thereby produce what is called a vacuum. See Vacuum. Air-furnace. — A furnace with a natural draft. See Wind-furnace. Albata.— An English name for German silver. See German Silver. Albumen. — This word means the white of an egg. It is found as an organic compound in both animal and vegetable substances. Albumen forms the starting-point of all animal tissue, and may be considered the raw mate- rial of fibrin, the substance which forms the basis or fibre of muscular tissue. Its composition is: carbon 52.8, oxy- gen 23.8, hydrogen 7.5, nitrogen 15.7. The most im- portant property of albumen is that of its coagulating or forming a white solid substance by the application of a gentle heat. Hence its use for many purposes in the arts and manufactures. See Agglutination. Alcohol. — The purely spirituous parts of liquors which have undergone vinous fermentation. Alcohol mixes with water in any proportion, giving out heat by the mixture; a mutual penetration of the parts takes place, so that the bulk of the two fluids when mixed is less than when separate. All the alkalies when pure, several of the neutral earths and metallic salts, sulphur in vapor, phos- Alkali. 4 Allowance. phorous, the essential oils, resins, gum-resins, wax, sper- maceti, biliary calculi, etc., are, in different proportions, soluble in alcohol. The substances which are insoluble in alcohol are the alkaline carbonates; all the sulphates; som© of the nitrates and muriates, metals; metallic oxides, and metallic acids ; all the pure earths; the fixed oils, unless when united to alkalies, or converted into drying oils by metallic oxides; muscular fibre; the coagulum of blood; and albumen. Alcohol is highly combustible, producing intense heat without smoke, and for this reason is well adapted to burn in lamps for chemical and other uses. See Fuel. Alkali. — Alkalies in their pure state possess the fol- lowing general properties ; to the taste they are caustic and acrid; they dissolve animal matter, and form a sapo- naceous compound with oils or fat; they combine with acids in definite proportions, but the respective properties of each are destroyed, and a neutral salt is the result. It is on this account that most metals are precipitated from their acid solutions by the introduction of an alkali. The most important alkalies are potash, ammonia, and soda — ammonia being soluble, while potash and soda are termed fixed alkalies. See Precipitation. Allowance. — A foundry phrase, of general applica- tion. For example: some portion of a mould of core is scraped or filed away to prevent actual contact of two fri- able surfaces when closing a mould is called allowance, or clearance. A small proportion of zinc, over and above the recognized formula, to compensate for what is lost by volatilization during the process of mixing, is alloivance. In fact, anything performed with the view of minimizing the possibilities of destroying the result of his labor, is recognized by the moulder as making allowance for such contingencies. Alloys. 5 Alloys. Alloys. — A combination or mixture of two or more metals. Metals combine with, metals to form alloys, and each compound, may be looked upon, for many purposes, as a new metal. Alloys are always more fusible than the most infusible metal of which they are composed. A metal of low fusibility, when melted in contact with one of high fusibility, causes the latter also to melt, thus acting as a flux. This principle is employed in soldering, or the join- ing of two metals by means of a third. See Soldering. In fact, no alloy composed of two metals, as copper and zinc, or copper and tin, either files or turns with the same facility as when a third metal is added to the alloy in suit- able proportions. Lead added to copper and zinc, and zinc to copper and tin, will effect this purpose. It should always be borne in mind that, in making alloys, the more infusible metals should be melted first; and in order that the admixture should be perfect, mechanical agitation must be effected by constant stirring with an in- fusible rod, or repeated pouring from one ladle or crucible to another. The surface of the metal should also be care- fully protected while in a fluid state from the oxidizing influence of the atmosphere. Ordinarily, resin, pitch, or wax will answer this purpose for all alloys having a low fusing-point; but for such as have a high fusing-point, borax, pounded glass, charcoal, or salt will answer. See Flux. Not many of the metals may be used by the founder without some alloy, and the following represent nearly all that are employed alone, viz., iron, copper, lead, tin, zinc, gold, silver, mercury, platinum, aluminum. Some are entirely too brittle to be used alone, but may be used for imparting hardness to other metals. Among these may be mentioned bismuth, arsenic, antimony, etc. But even copper may not be employed alone for castings, as such castings are invariably unsound, and are difficult to file or Alum. 6 Alum. machine; yet a suitable proportion of zinc alloyed with it renders it not only sound in the casting, but capable of being either machined, rolled, or hammered, and which constitutes, according to the amount of zinc used, many different kinds of the most useful alloy known, viz., brass. See Brass. Some of the changes produced by alloying are of great importance in the arts and manufactures, as many of the alloys produced are more valuable on account of their newly-acquired properties than any of the simple metals which enter into the composition. Strange as it may appear, a quarter of a grain of lead will render an ounce of gold perfectly brittle, although neither of the metals composing the alloy are brittle ones. Some metals which will not combine together immedi- ately may be united by the intervention of a third fusible alloy. Thus, mercury will not combine directly with iron, but if tin or zinc be first added to the iron, an amalgam may be formed of it with mercury (see Mercury; Amal- gam). When mercury is united with another metal the compound is called an amalgam. One remarkable feature in this connection is that alloys are, as a rule, more easily oxidized than their component metals. For example, it only requires to heat an alloy of tin and lead to redness, when it will at once unite with the oxygen, or take fire and burn. (All the alloys and metals of importance will be explained under their several names.) See Fluid Allot; Fusible Alloy. Alum, or sulp7iate of alumina and potash, is a triple salt of great importance in the arts and manufactures. Sometimes it is found native, but it is chiefly manufactured artificially from alum-slate. A large quantity is prepared in this country by treating alumina or clay with sulphuric acid, and after the lapse of a few months adding potash. Aluminum. t Aluminum. The whole is then leached and the alum separated from the solution by crystallization. It is of great importance in dye- ing, in the manufacture of leather, and in calico-printing. Alum is soluble in 16 parts of water at 60°, and in three- fourths of its weight of boiling water; its composition is: sulphate of alumina 36.85, sulphate of potash 18.15, water 45.00. Aluminum. — A bluish-white metal of remarkable brightness, its specific gravity being only a quarter that of silver (2.56), or about the same as porcelain. Next to oxy- gen and silicon, it is perhaps the most abundant element upon the earth's surface, and is more abundant than any other metal, as it is supposed to constitute one twelfth of the solid crust of the earth. Most rocks and soils hold enor- mous quantities of this metal in combination with oxygen and silicon, and slate, marl, feldspar, clay, and many other common minerals contain it in large proportions. Notwithstanding its abundance, it cannot be applied to the many uses for which it is so well suited, because as yet the methods for obtaining it are very costly, although considerable progress has been made of late in devising cheaper means to this end. The metal is malleable, duc- tile, and tenacious, and may be beaten into thin sheets, and drawn into fine wire, after the manner of silver. Ham- mering in the cold makes it hard, like soft iron; fusing softens it again. Hammering increases its specific gravity from 2.56 to 2.67. It melts at red heat, but does not oxidize at high temperatures; it is not acted upon by chemicals that would blacken silver, and because of this quality it preserves its lustre better than the latter metal, which is usually attacked by the sulphur contained in some foods, forming with the silver a dark composition. Nitric acid, even when concentrated, fails to touch it, and it is not soluble in dilute sulphuric acid. Concentrated Aluminum. 8 Aluminum. hydrochloric acid dissolves it with evolution of hydrogen. The metal is also dissolved with solutions of caustic potash or soda, which forms aluminate of potash or soda, giving off hydrogen. Aluminum is employed extensively in the manufacture of delicate apparatus, ornamental articles, etc., but it is as yet only valuable as an alloy with other metals, such as steel, cast-iron, copper, nickel, and some others, the quality of which is very perceptibly improved by certain additions of aluminum. The property of this metal, when combined with steel, iron, and copper, is to increase their tensile strength and resistance to oxidation. The fluidity of cast-iron is much improved by this metal, and it is claimed that the castings are much more sound and cleaner when alloyed with a surprisingly small amount of aluminum. Alloyed with brass or copper, it improves equally tensile strength, color, and durability, and gives a dense solid casting free from porosity. To effect the above result it is only necessary to flux with from \ to 1 per cent of alu- minum. The true bronze — aluminum 10, copper 90 — is a some- what brittle, gold-colored alloy at the first melting, but it increases in tenacity and strength with successive meltings, until at a dull red heat it may be forged and hammered until it has become cold, without presenting any cracks at the edges. One of the qualities possessed by aluminum bronze is that it may be made softer and more ductile by plunging into cold water while hot. The tensile strength of good bronze is about 90,000 pounds per square inch. In making this bronze in crucibles, use a layer of char- coal over the copper, but no flux. When the copper has melted, push the aluminum down into the molten copper before lifting out the crucible, after which it may be Aluminum. Aluminum. skimmed clean and poured. No time should be lost in handling this alloy after it has been well stirred and freed from slag. Small proportions of gold, silver, tin, or zinc increases the hardness, but does not materially affect the ductility of aluminum. Three per cent of zinc improves it; 7 per cent of tin impairs its lustre, and with lead, mercury, and antimony it will not combine. Articles made in this metal may be freed from the bluish tint, and made to appear like frosted silver by immersing in a hot solution of pot- ash. Soldering aluminum has so far proven a difficult task; most solders will not stick to the surface of alu- minum and owing to its high heat conductivity, the heat is very rapidly drawn away from any of the molten solders, causing them to freeze before flowing sufficiently. These difficulties have been largely overcome by having the aluminum to be soldered hot, the surfaces especially cleaned, and with very hot soldering bits or careful work with the blow pipe, and with special alloys for solders and special fluxes. Several such methods are successfully used. Soldering bits of nickel are better than copper ones, and especially good work has been done with those kept hot by a gasolene torch or electric appliance. Due to the peculiar nature of aluminum and its com- mercial impurities, ordinary hard solder (composed of, silver and tin), soft solder (composed of lead and zinc), or any of the ordinary forms of solder, do not "stick" to the metal. The Pittsburgh Eeduction Company have a process pro- tected by letters-patent for treating aluminum so that certain forms of solder will work satisfactorily with it. Due to the high heat conductivity of aluminum, the heat from the molten solder is conducted away from it so rapidly that it will not "flow under" as satisfactorily as could be desired. The above-mentioned company have Aluminum. 10 Aluminum. arrangements for overcoming this difficulty and soldering satisfactorily. The quality of ordinary bronze, or gun-metal (copper 90, tin 10), is much improved by an addition of about 2 per cent aluminum. All anti-friction metals, especially babbitt-metal, are im- proved by the addition of from \ to \ of 1 per cent aluminum. Steel is rendered more fluid for casting with by a small percentage of aluminum added to each ladleful of metal before pouring. From f to 1 pound to a ton of steel is usually sufficient for this purpose; it diffuses through the mass without stirring, makes sounder castings and freer from honeycomb. Its effect upon gray cast iron is not very pronounced, but white iron containing combined carbon 4.80, and no graphite, is changed to a gray iron containing graphitic carbon 3.45, combined carbon 0.93, by the addition of about 3.20 per cent of aluminum, thus causing an entire change from white iron to gray. Most type-metal mixtures are appreciably improved by a further alloy of from 5 to 10 per cent aluminum, the edges of the type being made harder and metal more dur- able. With nearly all brass mixtures it imparts a higher de- gree of homogeneity, and lessens the tendency to corro- sion. Zinc galvanizing is made more easy of accomplishment, and with improved results, by adding a slight proportion of aluminum to the zinc, a thinner and more tenacious coating being made possible by this means. Besides the numerous aluminum alloys given elsewhere, there are many new compositions which are claiming con- siderable attention, in which aluminum enters as a princi- pal ingredient, some of which are as follows : Aluminum. 11 Aluminum. Bonrbounz-metal contains aluminum 85.74, tin 12.94, silicon 1.32. Nickel-aluminum contains aluminum 8, nickel 20. Metalline contains aluminum 25, copper 30, cobalt 35, iron 10. Rosine, for jewelry, contains aluminum 30, nickel 40, tin 20, silver 10. Cobalt-bronze contains aluminum 10, copper 40, cobalt 50. See Aluminum Alloys; Aluminum-bronze Alloys. The impurities most commonly found in aluminum are silicon and iron, and it may be said of the metal made by the Pittsburgh Reduction Company that these two impuri- ties are the only ones found. Silicon in aluminum exists in two forms, one seemingly combined with aluminum as combined carbon exists in pig-iron, and the other as an allotropic graphitoidal modification. For many purposes the pure aluminum cannot be so ad- vantageously used as that containing 3$ or 4$ of impuri- ties, as the pure aluminum is soft and not so strong as the less pure. It is only where extreme malleability, ductility, sonorousness, and non-corrodibility are required, that the purest metal should be used. The purity of commercial aluminum varies from 94$ to 99.75$. The Pittsburg Reduction Company sells its com- mercial aluminum in three grades. The No. 1 grade of aluminum has an analysis approxi- mately as follows : Silicon 0. ovyo. Iron 0.25$. Aluminum 99.: They always have, however, in stock metal still purer than this; some running as high as 99.90$ pure, which is sold at an added price for special uses. Aluminum. 12 Aluminum. The ~No. 2 grade ordinarily runs quite uniform in com- position, and has an analysis approximately as follows : Silicon 3$. Iron lfo. Aluminum 96$. This metal, however, is not guaranteed to be over 94$ pure. Sound ingots of the No. 1 grade metal, suitable for roll- ing, are kept in stock of the following sizes : 12 inches x 18 inches x If inch. 12 " x 181 « * ii. « 11J " x 16J " x 1 " 12£ " x 6 " x f " 5£ " x 2 " x \ « Aluminum for remelting is kept in stock of the various grades of metal, in what are called "waffle" ingots. They are square placques, three inches on a side and of about f inch thickness, and weigh about one half pound each. They are connected together with thin webs. A sheet of aluminum twelve inches square and one inch thick weighs 14.12 pounds; a bar of aluminum one inch square and 12 inches long weighs 1.176 pounds; a bar of aluminum one inch in diameter and 12 inches long weighs 0.918 pounds. Weight. — The weight per cubic inch of cast aluminum is .092 lb.; of rolled aluminum, .098 lb. The weight per cu. ft. of cast aluminum is .158.989 lbs. The weight per cu. ft. of rolled aluminum is. 169.510 lbs. The weight per cu. ft. of wrought iron is. . .480.000 lbs. The weight per cubic foot of soft steel is 490.450 lbs. The weight per cubic foot of brass is 524.160 lbs. The weight per cubic foot of copper is 558.125 lbs. Aluminum. 13 Aluminum. The weight of a given bulk of cast aluminum being 1, soft steel or iron is 3.0 times as heavy; copper is 3.6 times as heavy; nickel, 3.5 times as heavy; silver, 4 times as heavy; lead, 4.8 times as heavy ; gold, 7.7 times as heavy, and platinum 8.6 times as heavy. Strength. — The tensile, crashing and transverse tests of aluminum vary very considerably with different conditions of hardness, due to cold working ; also by the amount of work that has been put upon the metal, the character of the section, etc. Oast aluminum has about an equal strength to cast iron in tension, but under compression is comparatively weak. The following is a table giving the average results of many tests of aluminum of 98.5 $ purity : Elastic limit per sq. in. in tension (castings) 8,500 " (sheet) 12,500 to 25,00 J " " " " (wire) 16,000 to 30,000 (bars) 14,000 to 25,000 Ultimate strength per sq. in. " (castings) 18,000 " " (sheet) 24,000 to 50,000 " * " " (wire) 30,000 to 65,000 " " " " (bars) 28,000 to 45,000 Per cent of reduction of area in tension (castings) 15 « " " (sheet) . . 20 to 30 " " " (wire) . . 40 to 60 " " « « (bars)... 30 to 40 Elastic limit per square inch under compression in cylinders, with length twice the diameter 3,500 Ultimate strength per square inch under compres- sion in cylinders, with length twice the diameter. 12,000 The modulus of elasticity of cast aluminum is about 11,000,000. Aluminum. 14 Aluminum. Aluminum in castings can readily be strained to the unit stress of 1500 lbs. per sq. inch in compression, and to 5000 lbs. per sq. inch in tension. It is rather an open metal in its texture; and for cylinders, to stand pressure, an increase in thickness over the ordinary formulas should be given to allow for its porosity. Under transverse tests, pure aluminum is not very rigid, although the metal will bend nearly double before break- ing, while cast iron will crack before the deflection has be- come at all large. The texture and strength of aluminum are greatly improved by subjecting the ingots to forging or pressing at a temperature of about 600° Fahrenheit. Taking the tensile strength of aluminum in relation to its weight, it is as strong as steel of 80,000 pounds per square inch. Comparative results in this way are tabulated below as taken from Eichards' work on "aluminum." Weight of 1 Cubic Foot in Pounds. Tensile Strength per Square Inch. Length of a Bar able to Support its own Weight in Feet. 444 525 480 490 168 16,500 36,000 50,000 78.000 26,800 5,351 9,893 15,000 Hard structural steel 23,040 Aluminum 23,040 Eolled Copper has a specific gravity of 8.93. One cubic foot weighs 558 T V 2 o 5 o ^ Ds - ^ ne square foot of one inch thick weighs 40^0 lbs. Eolled Aluminum has a specific gravity of 2.72. One cubic foot weighs 169 ^fo 1DS - ^ ne s( l u ' ire foot of one inch thick weighs 14 T 1 /o- 6 o 10s - Eolled copper is 3.283 times heavier than similar sections of rolled aluminum. Aluminum. 15 Aluminum. COMPARATIVE WEIGHT OF METALS. Weights per Square Foot 1 Inch Thick. Approximate Percentage. Metals. Heavier than Iron. Lighter than Iron. Iron, rolled 40.000 40.833 14 126 43 68 46 51 100.8 59 80 43.2 54.75 38. 37.6 2 per ct. 7 per ct. 13 " 150 " 50 " 7 " 361 " Steel, " Aluminum, " 62.91 per ct. Brass, " Copper, " Gold, " .... Lead, " .... Nickel, <* .... Silver, " .... Tin, " 5 per ct. 6 *« Zinc, " TENSILE STRENGTH OF SOME ALUMINUM BRASS ALLOYS. Tensile Strength Aluminum. Copper. Zinc. per Square Inch. Lbs. 1.00 57.00 42.00 68,600 1.15 55.80 43.00 70,200 1.25 70.00 28.00 36,900 1.50 78.00 27.50 42,300 1.50 77.50 21.00 33,417 2.00 70.00 28.00 52,800 2.00 70.00 28.00 52,000 2.50 68.00 30.00 65 400 3.00 67.00 30.00 68,600 3.30 63.00 33.30 86,700 3.30 63.30 33.30 77,400 3.30 63.30 33.30 92,500 3.30 63.30 33.30 90,000 5.80 67.40 26.80 96,900 Aluminum. 16 Aluminum Alloys TABLE SHOWING WEIGHT IN POUNDS OF SHEET AND BAR ALUMINUM AND BRASS. Rolled brass is 3.021 times heavier than rolled aluminum. Rolled steel is 2. 890 times heavier than rolled aluminum. Thickness or Diam- eter in Inches. 1-16 1-8 3-16 1-4 5-16 J5-8 7-16 1-2 9-16 5-8 11-16 3-4 13-16 7-8 15-16 1 1.1-16 1.1-8 1.3-16 1.1-4 1.5-16 1.3-8 1.7-16 1.1-2 1.9-16 1.5-8 1.11-16 1.3-4 1 13-16 1.7-8 1.15-16 2 Sheets per Square Foot. Alum'um. Brass. Steel .884 1.769 2.647 3.530 4.412 5.294 6.177 7.060 7.942 8.824 9.706 10.590 11.470 12.35 13 23 14.12 15.00 15.88 16.76 17.64 18.52 19.41 20.30 21.18 22.06 22 94 23.82 24.70 25.58 26.46 27.43 28.22 2.7 5.41 8.12 10.76 13.48 16.25 19. 21.65 24.3 27.12 29.77 32.46 35.18 37.85 40.55 43.29 45.95 48.69 51.4 54.18 56.85 59.55 62.25 65. 67.75 70.35 73. 75.86 78.55 SI. 25 84. 2.556 5 112 7.65 10.20 12.75 15.30 17.85 20.40 22.95 25.50 28.05 30.60 33.15 35 70 38.25 40.80 43.35 45.90 48.45 51.00 53.55 56.10 58.65 61.20 63.75 66.30 68.85 71.40 73 95 76.50 79.05 81.60 Square Ban One Foot Long. Alum'um. Brass. .00450 .015 .01834 .055 .04118 .125 .073364 .255 .1152 .350 .1654 .51 .2253 .69 .2941 .905 .3723 1.15 .4595 1.4 .5564 1.72 .6620 2.05 .7768 2.4 .9008 2.75 1.034 3.15 1.176 3.65 1.328 4.08 1.488 . 4.55 1.659 5.08 1.838 5.65 2.027 6.22 2.224 6.81 2.431 7.45 2.647 8.13 2.872 8.83 3.107 9.55 3.350 10.27 3.602 11. 3.865 11 82 4.135 12.68 4.415 13.5 4.706 14.35 Steel. .013 .053 .119 .212 .333 .478 .651 .850 1.076 1.328 1.608 1.913 2.245 2.603 2.989 3.400 3.838 4.303 4.795 5.312 7 857 6.428 7.026 7.650 8.301 8.978 9.682 10.41 11.17 11.95 12.76 13.60 Round Bars One Foot Long. Alum'um. Brass. Steel .00346 .01453 .03253 .05780 .09032 .12970 .1768 .2308 .2924 .3609 .4367 .5198 .6104 .7074 .8122 .924 1.043 1.169 1.303 1.444 1.592 1.747 1.909 2.079 2.256 2.440 2.631 2.830 3.036 3.249 .011 .045 .1 .175 .275 .395 .54 .71 .9 1.1 1.35 1.55 1.85 2.15 2.48 2.85 3.20 3.57 3.97 4.41 4.86 5.35 5.85 6.37 8.05 8.65 9.29 9.95 10.58 11.25 .010 .042 .094 .167 .261 .375 .511 .6(;7 .845 1 0-13 1.262 1.502 1 763 2.044 2.347 2.670 3 014 3.379 3.766 4 173 4.600 5.0 ;9 5.518 6.008 6.520 7.051 7.604 8.178 8.773 9.388 10.02 10.68 Aluminum Alloys. — The following alloys comprise most of those which are in common use. Such alloys as have been made with other metals have not as yet been recognized as having any practical value in arts or manu- factures. Aluminum Bronze. 17 Aluminum Bronze. Aluminum silver, for fine instruments Alloy, for watch-springs, etc Aluminum bronze, bard malleable gold color soft " " " " medium " greenish gold. Solid copper castings Aluminum copper, for engraving Alloy, bard as coin-silver Ailoy, extremely hard Alloy, ductile, hard, greenish. . . . , Alloy, brittle, ciystalline ,'. Alloy, harder than aluminum and polishes well. . Alloy, similar to 14-carat gold Gun-metal, with aluminum alloy, equal to cast- steel in strength ; good for bells, etc a p c a P. a o o 73 a < o a 6 a N a '§ o Good Lining for general use 1 17 85 Good Bearing (not a lining) ( " «« " ) 1 10 ' ' 8 10 24 0.5 1 13.97 10 9.49 2.44 8 25 2 24 72 ... Lining (soften with lead if too hard) 1 1 24 17 20 86.03 82 73.96 89.02 79 n i 16 16 4 ....2 ..... Lining Journal-box Lining, to be melted and run into ingots first Lining subject to heat. . . Lining subject to shock 0.25 1 6 Lining for Loco. Axle-tree " " " French.. 8 9.03 7.76 5 " " " English.. " " " " Belgian.. " " " " Stephenson 7.09 0.43 0.78 Extra Lining (melt tin and antimony and pour to the melted copper). . . 3 Lining, for a heavy weight Hard Bearin g * Very Hard Bearing ( mix for hard- Lining for Car-axles •< ening 8 (then add 100 15 8 Hardening for Babbitt's Metal 4 24 (For linings use 1 pound of hard- ening to 2 pounds of tin.) See Babbitt's Metal ; Fenton's Antifriction Metal. Antimony. — This is a brilliant white metal of a crys- talline texture and bluish white color, and so brittle that it cannot be rolled into sheets nor drawn into wire. Its specific gravity is 6.71; melts at 810°, crystallizes in pyramids, and volatilizes at an intense heat. There are several varieties of the ore, but the sulphuric, or gray antimony, is the most abundant, and yields the metal of commerce. To reduce the ore it is first made into a powder, after which it is heated in a reverberatory furnace; Antimony. 32 Antimony. the melted sulphuret then flows from the infusible 1 earthy matter, and is subsequently smelted and purified. Ex- posed to the air at ordinary temperatures antimony does not rust; this property, combined with its hardening in- fluence on other metals, renders it eminently useful in the composition of many useful alloys to make them harder and whiter. It is usually found associated with other metals, but always contains more or less iron. The crude metal, or sulphuret, is employed for purifying gold, the sulphur from which being readily absorbed by the inferior metals, while the antimony unites with the gold. Antimony has generally been distinguished as Regulus, or petty king, because of the hardening influence previously mentioned; alloyed with an equal quantity of tin we have a brilliant white and somewhat hard alloy suitable for some descrip- tions of specula. Sodium and potassium are the metals with which antimony unites the most readily, as, even when the former are alloyed with other metals, the associa- tion is found to be of an intimate character. Antimony readily combines with gold, but destroys the ductility of the latter, producing a granular alloy of a golden tint, the depth of which is proportionate to the amount of gold present. Antimony contracts little or none in cooling. For this reason it is doubly valuable in the production of types, music and other plates, etc., as, besides giving the re- quisite degree of hardness to such alloys, it enables the founder to obtain a true copy of the matrix — something almost impossible in most of the other metals employed for this purpose, owing to their high shrinking qualities. For a large variety of alloys iu which antimony enters as an ingredient, see White Alloys; Type-metal; Anti- friction Alloys; Pewter; Britannia Metal; Queen's Metal; Music Metal; Speculum Metal; Solders, Apothecaries' Weight. 33 Arsenic. Apothecaries' Weight. — In this arrangement the pound contains 12 ounces; each ounce 8 drachms; each drachm 3 scruples, and each scruple 20 grains. Apprenticeship.— See Technical Education for the Moulder. Aqua-regia. — Royal-water, so called from its power to dissolve gold, the king of metals. Its scientific name is nitro-muriatic acid. See Gold. Arabic Gum. — Gum-arabic is a gum which flows from the acacia tree on the banks of the Nile, Arabia, and in some other parts. It forms a clear, transparent mucilage with water, and is insoluble in alcohol or ether. Arbor. — See Core-arbor. Argent an. — Imitation silver. See White Argen- tan. Argol-flux. — A flux made from impure cream of tartar or acid tartrate of potash, which constitutes the in- crustation on the insides of wine casks. See Flux. Arm. — A spindle attachment for carrying the sweep- board which forms a mould. See Spindle. Arsenic. — Arsenic is sometimes found pure, but more generally combined with nickel, cobalt, sulphur, and iron. To separate arsenic from the ores, they are first crushed and the arsenic dissipated in a reverberatory furnace by roasting, when the arsenious acid is condensed into white arsenic. The metal is obtained from white arsenic by in- corporating it with carbonaceous matter and heating in Arsenious Acid. 34 Arsenious Acid. a closed crucible provided with a receiver, in which the arsenic is condensed as a brittle white metal with a slight degree of lustre; the specific gravity of which is 5.7, its melting-point being 400°. At 500° it volatilizes without fusing, the vapor having a strong tincture of garlic. The metal may be powdered in a mortar. The chief property of arsenic is to promote the union of metals that would be otherwise difficult to mix — aluminum with iron ; lead with zinc ; lead with iron, etc. It pro- motes the fusion of many metals, and occasions some re- fractory ones to melt at a low temperature. Being a union rather than a true alloy, it is customary to call all alloys of arsenic by the name of arsenides. While arsenic, like antimony, tends to crystallize other metals, they are not rendered as brittle as the latter metal makes them. Nearly all metals combine with arsenic ; but, except in the case of silver and gold, such alloys may be decomposed by lengthened fusion. White tombac is copper alloyed with arsenic. The metal for lead-shot is rendered more fusible and solid by a slight proportion of this metal, and gold may be permanently alloyed to form a brittle arseniuret of gold by exposing the heated metal to its vapors. From J to j of an ounce to the pound of any alloy will materially assist in preventing a tendency to porosity, but will result in a harder casting, somewhat lighter in color. Speculums and all similar objects are, by means of this metal, made hard, white, and lustrous. For the manner of fluxing alloys of arsenic, also the methods employed for introducing this metal into the crucible, and alloys containing arsenic, see Speculums; Tombac; Lead-shot; Cobalt. Arsenious Acid. — White arsenic. See Aksekic; White Aesenic. Artificial Diamond. 35 Asbestos. Artificial Diamond.— See Diamond. Artificial Gold. — A French substitute for gold is made as follows : Melt copper, 100 ; then add separately and by degrees, in powder, magnesia 6 ; sal-ammoniac 4^ ; quick-lime J-; tartar 9; and stir half an hour — after which add zinc, or, preferably, tin 17. Mix well, and continue the fusing for 35 minutes, with the crucible well covered before casting. This alloy does not corrode easily ; when it does tarnish its former brilliancy can be restored by dipping in acid solution. See Gold Alloys. Artificial Stone.— See Stone. Art-work. — This term is usually employed to mould- ing fine-art work, and comprises all castings moulded from models prepared by the sculptor or modeller. Such cast- ings in the past have invariably been cast in bronze and kindred alloys, but very much of that which enters into both interior and exterior decoration is now produced in cast iron. The latter class of castings would prevail more extensively, if the moulders with skill sufficient to produce it were more numerous. The great dearth of such artists can only be relieved by improving the education of our youth, who by all means should be encouraged to cultivate a taste for the fine arts, as well as qualify themselves for its manipulation in the foundry, in institutes conducted for the special benefit of apprentices in all branches of the metal industries. See Technical Education for the Moulder ; Modelling ; Statue-founding, Asbestos. — A mineral of white or gray color, appear- ing almost like a vegetable substance, because of its fibrous, flexible, and delicate texture. It is incombustible, and the ancients wove it into cloth in which to preserve the ashes Ashes. 36 Assay. of bodies burned on the funeral pyre. There are other varieties of this mineral, all of which pertain to the different species of hornblende, and consist chiefly of silica, magnesia, lime, and oxide of iron. Its uses for manufacture into in- combustible material have now become too numerous for mention here. See Befractory Materials. Ashes is what remains of animal or vegetable sub- stance after burning with free access of air. The ashes of organic substances consist of the fixed salts contained in them — land-plants yielding salts of potash, etc., and sea- plants soda, with some iodine. Turf contains alkalies and some sand ; so also does coal, with the addition of some iron occasionally. See Potash ; Alkalies. Asplialtum. — This substance resembles pitch, but has a higher internal polish, and is sometimes called mineral - pitch, bitumen, etc. ; it breaks with a polish, melts easily, and when pure burns and leaves no ashes. Anciently, it was only procurable from Lake Asphalites (Dead Sea), in Judea, for which reason it is sometimes also called Jews 5 pitch. It formed a building cement for the Babylonians, and is now much used in flooring, roofing, paving, etc. See Petroleum ; Bitumen. Assay, — The determination of the quantity of any par- ticular metal in an ore, alloy, or other metallic compound, more especially of the quantity of gold or silver in coin or bullion. It differs from analysis thus : The component parts of the mineral or alloy are, by analysis, separated, and an estimate made of their respective quantities ; while by assay, it is only the valuable metals that are sought for ; as, in the case of silver and gold alloys the inferior metals are dispersed, the quantity being determined by the loss of weight. A gold alloy is assayed by obtaining a certain Atmosphere. 37 Axis. number of grains, which, after being carefully weighed, are wrapped in sheet-lead and exposed to intense heat in a cupel placed under a muffle. Cupels for this purpose must be very porous, and are simply a small block with a cavity on the upper side to receive the metal. When fusion takes place, the lead is converted into a vitreous oxide, which, acting as a flux, acts powerfully to oxidize and vitrify the inferior metals contained in the alloy, which being changed, are absorbed by the porous cupel, leaving a globule of un- oxidable metal behind. The globule will be silver or gold, or a compound of both, which may be separated by the method shown at " Separating Metals from their Alloys." Another method of assaying is described at "Touch- needle." See Muffle. Atmosphere.— See Air; Thermometer. Avoirdupois Weight. — The system of weights and measures for all goods except precious metals and gems, the grain being the foundation of this as in the case of Troy weight. The weight of one cubic inch of water is 252.458 grains, and 7000 of these grains. make one pound avoirdupois, and 5.760 a pound troy. The pound is divided into 16 ounces, and the ounce into 16 drachms. The hundred-weight is, in most parts of the United States, simply 100 pounds avoirdupois, and the ton 20 of such hundredths, or 2000 pounds. Axis is the straight line about which a plane figure revolves so as to produce or generate a solid; or, it is a straight line drawn from the vertex of a figure to the middle of the base. The axis of a sphere or circle is a straight line passing through the centre and terminating at the circumference on the opposite sides. In founding, the spindle is an axis around or upon Babbitt Metal. 38 Sacking. which a sweep-board revolves to produce a solid, as a core by using the sweep's inner edge. When the outer edge of the sweep is used it forms an inclosing surface, or cope. See Spindle. B. Babbitt Metal. — To make this composition, melt copper 4; then add gradually tin 12, antimony 8, and a further addition of tin 12. When about 4 or 5 pounds of the final addition of tin has been added the heat may be reduced to a dull red, and the remainder added. Or, the copper, tin, and antimony may be melted first in sepa- rate crucibles; then poured together into one vessel and the final addition of tin introduced. The above is a hardening. For lining take 1 pound of hardening and melt it along with 2 pounds of tin, which produces the lining metal for use. It will be seen that the resultant mixture contains: copper 4, tin 96, anti- mony 8. Banca-tin and the best quality of copper and antimony is to be employed when it is desired to make good antifriction metal. See Antifriction Metals; Alu- minum. Back. — An abbreviation for " Draw-back." See Draw- back. Backing" out is the method of producing a pat- tern or casting, equal in thickness all over, from a carved wooden block or a rough plaster-cast. The backiog out of such blocks by the moulder saves much carving, and will ordinarily produce a more regular thickness throughout. The method is as follows : two copes are pinned to fit one nowel, the block is set face up in one of them, and an extra hard impression obtained in the nowel. This impression Bag. 39 Bail. is then transferred to the same cope; also rammed extra hard, and when lifted laid face up on the floor— after which the block is drawn from the nowal and thicknessed with a suitably prepared layer of clay. The parting is then pre- pared and the impression taken in the second cope in a proper manner for casting, as this is the mould-surface or back of the intended object to be cast. It only remains to return the block into the first cope, and, after removing the first hard-rammed nowel-mould, return the flask to receive the final impression, which in this instance must be rammed with the customary care, as this forms the front or face. Both cope and nowel are by this means obtained from the first cope, and must as a consequence be a perfect match at the parting, the space formed by the clay answer- ing to the design back and front. If it is desired to accomplish this by casting the moulds face up, the block is placed in the nowel face up, and a correct parting, made very hard, formed all round it. The first receives the intended mould-impression, after which the second cope is rammed extra hard thereon, so that a hard working-face may be obtained on which to lay the clay thickness. It is then ready for the nowel proper; and when the latter has been duly rammed and the whole reversed, the dummy cope is removed, clay lifted out, mould finished, and the previously rammed first cope placed over it. As in the former case, the partings in both nowel and cope are obtained from one original, and must con- sequently match. SeeTmcKNESSiNG; Kettles; Statue- founding. Bag. — See Blacking-bag. Bail. — The arched iron yoke, provided with journals, in which the ladle is suspended whilst pouring. See Ladle. Baking. 40 Bar. Baking. — A term used in some localities in relation to the process of drying cores or moulds in the oven. See Oven. Balls. — The following table gives the weight of cast- iron, copper, brass, and lead balls from 1 to 12 inches diameter. To obtain the weight of balls larger in diameter than is given in the table, ascertain the number of cubic inches contained in the sphere by multiplying the cube of its diameter by .5236; then multiply by the weight of a cubic inch of the metal composing the ball, as follows : For cast-iron and tin, multiply the total cubic inches, as found by the above rule, by .263, and the product will be the weight in pounds. For copper, multiply the total cubic inches by .317. For brass, multiply the total cubic inches by .282. For lead, multiply the total cubic inches by .410. TABLE SHOWING WEIGHT OF CAST IRON, COPPER, BRASS, AND LEAD BALLS FROM 1 TO 12 INCHES DIAMETER. Dia. Cast Iron. Cop- per. Brass. Lead. Dia. Cast Iron. Cop- per. Brass. Lead. 1 .136 .166 .158 .214 7 46.76 57.1 54.5 73.7 1* .46 .562 .537 .727 n 57.52 70.0 67.11 90.0 2 1.09 1.8 1.25 1.7 8 69.81 85.2 81.4 110.1 2} 2.13 2.60 2.50 3.35 8^ 83.73 102.3 100.0 132.3 3 3.68 4.5 4.3 5.8 9 99.4 121.3 115.9 156.7 3J 5.84 7.14 6 82 9.23 % 116.9 143.0 136.4 184.7 4 8.72 10.7 10.2 13.8 10 136.35 166.4 159.0 215.0 4£ 12.42 15.25 14.5 19.6 10| 157.84 193.0 184.0 250.0 5 17.04 20.8 19.9 26.9 11 181.48 221.8 211.8 286.7 5£ 22.68 27.74 26.47 36.0 11* 207.37 253.5 242.0 327.7 6 29.45 35.9 34.3 46.4 12 235.62 288.1 275.0 372.3 6* 37.44 45.76 43.67 59.13 Bar. — A flask consists of sides, ends, and bars (cross- bars). The latter connect the sides, and form spaces in which rammed sand is held securely. When flasks exceed Bar-iron. 41 Basic Process. a certain size, the sand's adhesiveness is insufficient for its own support: it is then that bars are introduced to lessen the space, and thus restore their usefulness; in other words a large flask with bars is simply a number of narrow flasks, side by side, and raised a little higher than the sides to admit of a sand junction being made underneath, and thus secure a continuous sand surface. See Flasks. Bar Iron See Malleable Iron. Barium. See Strontium. Barrel. See Tumbling-barrel; Core-barrel. Barrow. See Wheelbarrow. Basalt. — A rock of igneous origin, usually of a dark green or blackish color, consisting chiefly of the minerals augite and feldspar, with grains of magnetic or titanic iron. It occurs amorphous, tabular, or globular, but, as in the Giant's Causeway, Ireland, it is usually columnar. See Amorphous. Base-plate. See Foundation-plate. Basic Process. — A process of making steel by blow- ing the metal in converters lined with dolomite in place of gannister, as in the Bessmer process. Dolomite is a mag- nesian limestone, which, being well burned and ground, is mixed with tar to give it consistency. This can then be rammed in the converters, or pressed into bricks for lin- ing with. This basic lining absorbs some of the phos- phorous present in the iron, the rest being taken up by the lime, which constitutes about 15 per cent of the charge, and is introduced before the molten iron enters the con- Basin. 42 Beach sand. verter. See Bessemer Steel; Converter; Gannister; Dolomite. Basin is sometimes termed a pouring -basin, or run- ner, and is a suitably formed reservoir constructed with sand within a wood or iron box-frame. Its purpose is to receive the metal from the pouring-ladle, and con- nection with the mould is made by down-runners, which lead from its lowest part, either to the mould direct, or to some system of runners which lead to it. See Down-gate; Gates; Runner; Basin. Bath. See Tinning; Tin-plate. Bath-metal. — A cheap jewelry alloy, composed of brass 32, zinc 9. See Tombac. Bauxite. — A ferric oxide, usually containing alumina 50.4, sesquioxide of iron 26.1, water 23.5. Some samples have more silica and less iron. The purest is called alu- minum ore, and is used in the manufacture of that metal. It is very refractory, being practically infusible, although containing over 20 per cent of iron oxide, while 4 or 5 per cent of the latter in some clays renders them easily fusible. Bauxite bricks are made by adding about 8 per cent of clay and plumbago for binding to the calcined bauxite, the re- sult being that as soon as intense heat is applied the plumbago partially reduces the iron and the brick is rendered practically infusible. These bricks are more durable than ordinary fire-bricks, will resist the most intense heat as well as the action of basic slags. They also become harder with use. See Fire-brick; Refrac- tory Materials. Beach-sand.— See White-sand. Bead-slickers. 43 Bed. Bead-slickers, — Tools maae expressly for smooth- ing the surface of bead-mouldings. See Slicker. Beam. — The foundry lifting-beam consists of a rec- tangular beam of wrought or cast iron, or wood, mounted with straps and ring to hang central in the block-hook of a crane. Notches sunk at equal intervals from each end allow of a balanced lift being taken with a pair of slings which fit the beam at one end and the flask-trunnions at the other, by which means the flask can be turned clear over before it is rested. By means of beam-hooks, chains may be hitched at any number of places along the sides. See Slings ; Beam-hook. A sound oak beam would require to measure four times the thickness of cast-iron to be of equal strength. The table at page 44 will be found of great service when it is desired to construct a cast-beam for the purpose as described above, or for any other purpose for which cast iron beams are applicable. Beam-hook. — A link-hook to slide along the beam to any required notch, the hook serving to suspend the chain for lifting with. See Beam. Beam-sling.— A sling with its upper end forged to fit the beam used, the lower end being made to two diame- ters; the larger one for passing over the collar of the trun- nion, the smaller to fit the body of the same. See Sling ; Beam ; Trunnion. Bearing.— See Core-print ; Seating. Bed. — A term applied to numerous things occurring in foundry practice. When a prepared surface is formed in the floor on which to lay the pattern it is usually called a Table. 44 Table. TABLE, Showing the Weight or Pressure a Beam of Cast Iron, 1 inch in breadth, will sustain, without destroying its elastic force, when it is supported at each end and loaded in the middle of its length, and also the de- flection in the middle which that weight will produce. By Mr. Hodgkinson, Manchester. Length. 6 feet. 7 feet. 8 feet. 9 feet. 10 feet. Depth in In. Weight Defl. Weight Defl. Weight Defl Weight Defl. Weight Defl. in Lbs. in In. in Lbs. in In .33 in Lbs. in In. in Lbs. in In. in Lbs. 765 iu In. 3 1,278 .24 1,089 954 .426 855 .54 .66 3£ 1,739 .205 1,482 .28 1,298 .365 1,164 .46 1,041 .57 4 2,272 .18 1,936 .245 1,700 .32 1,520 .405 1,360 .5 ^ 2,875 .16 2,450 .217 2,146 .284 1,924 .36 1,721 .443 5 3,560 .144 3,050 .196 2,650 .256 2,375 .32 2,125 .4 6 5,112 .12 4.356 .163 3,816 .213 3,420 .27 3,060 33 7 6,958 .103 5,929 .14 5,194 .183 4,655 .23 4,165 .29 8 9,088 .09 7,744 .123 6,784 .16 6,080 .203 5,440 .25 9 # 9,801 .109 8,586 .142 7,695 .18 6,885 .22 10 12,100 .098 10,600 .128 9,500 .162 8,500 .2 11 12,826 .117 11,495 .15 10,285 .182 12 15,264 .107 13,680 .135 12,240 .17 13 16,100 .125 14,400 .154 14 18,600 .115 16,700 .143 12 feet. 14 feet. 16 feet. 18 feet. 20 feet. 6 2,548 .48 2,184 .65 1,912 .85 1,699 1.08 1,530 1.34 7 3,471 .41 2,975 .58 2,603 .73 2,314 .93 2,082 1.14 8 4,532 .36 3,884 .49 3,396 .64 3,020 .81 2,720 1.00 9 5,733 .32 4,914 .44 4,302 .57 3,825 .72 3,438 .89 10 7,083 .28 6,071 .39 5,312 .51 4,722 .64 4,250 .8 11 8,570 .26 7,346 .36 6,428 .47 5,714 .59 5,142 .73 12 10,192 .24 8,736 .33 7,648 .43 6,796 .54 6,120 .67 13 11,971 .22 10,260 .31 8,978 .39 7,980 .49 7,182 .61 14 13,883 .21 11.900 .28 10,412 36 9,255 .46 8,330 .57 15 15,937 .19 13,660 .26 11,952 .34 10,624 .43 9,562 .53 16 18,128 .18 15,536 .24 13,584 .32 12,080 .40 10,880 .5 17 20,500 .17 17,500 .23 15,353 .30 13,647 .38 12,282 .47 18 22,932 .16 19,656 .21 17,208 .28 15,700 .36 13,752 .44 Note.— This table shows the greatest weight that ever ought to be laid upon a beam for permanent load; and if there be any liability to jerks, etc., ample allowance must be made; also, the weight of the beam itself must be included. Bed- board 45 Bedding-block. bottom bed. Sand that has been rammed on the bottom of a cupola or furnace, for the molten metal to rest upon, is the cupola, or furnace-bed. Open sand-plates are cast on beds, constructed by means of two straight-edges, — a parallel straight-edge and a level, — thus : one straight-edge is packed until it agrees with the level ; the other is the set at the required distance, and, by means of the parallel straight-edge, each of its ends are made to agree with the level, the proof of which is obtained by trying the level on the second straight-edge, when the level will be exact if the operation has been correctly performed. The sand within the straight-edges is then brought to the requisite density, extending some little above, when another straight- edge, long enough to reach across, will serve to strike off the superfluous sand and leave a bed that will be level in every direction. See Beddlng-ln"; Sand-bed; Level; Strickle. Bed-board. — A board on which to ram the nowal part when the bed is formed by the method of rolling-over (see Bolling-over). It may be of iron, wood, or plaster, with dimensions corresponding to outer edges of the flask used. Besides presenting a surface which accurately matches the upper side of the pattern, to prevent any possibility of the pattern being rammed out of shape, it must be made strong enough to lift the body of sand con- tained, when bed -board, nowal, and bottom-board are secured together for rolling-over ; as any deflection will irretrievably destroy what would otherwise have been a correct impress of the pattern. See Follow-board ; Turnover-board ; Bottom-board. Bedding-block. — A block of hard wood, with a smooth under surface and rounded edges, for bedding- down patterns with the hammer. This block should be Bedding in. 46 Beer. of such dimensions and shape as will be least likely to damage the pattern when struck with the hammer. See Bedding-in. Bedding-in. — One process for obtaining an impres- sion in the sand, of the lower or under side of the pattern. Simple objects may be pressed, or hammered into a suit- ably prepared soft bed of sand, while those of a more com- plex nature must have the sand tucked with the hand, or forced with small rammers into remote parts ; supplement- ing these operations by effectual ramming with the ordi- nary peen and butt-rammers — which operation extends to all parts of the hole or pit in which the mould is being prepared. Should this be neglected, the inside pressure^ when the mould is cast, will press the surface back into the soft parts and a swelled, uneven surface will result. This process may, in some instances, be simplified and made more effective by suitably dividing the pattern and ramming each piece separate, from the bottom upwards. Again, it may be found convenient to form some portion, if not all of the bed, by extemporized strickles and guides before lowering on the pattern for a final ramming. See Hamming ; Venting ; Tucking ; Tramping. Bed-fuel is the fuel resting on the sand - bed or bottom of the cupola and immediately preceding the first charge of iron, the amount of which is regulated according to the diameter of the cupola and the depth of the bottom. If coal be the fuel used, about 15 inches above the tuyeres would be sufficient for bed-fuel, and about 22 inches for coke. See Cupola; Charging the Common Cupola. Beer. — Owing to the hardening influence of the gluten, starch, albumen, etc., contained in beer, the bottoms of barrels, and sometimes the' beer itself, was formerly used Beeswax. 47 Bell- founding. extensively for hardening the surface of cores and moulds, being sprinkled thereon before they were placed in the oven to dry. It has, however, been to a great extent superseded by molasses- water, glue-water, and the very numerous patented core-washes which may now be obtained from the foundry-supply dealers. See Core-sand; Core- wash; Molasses; Glue. Bees-wax. — An excellent substance for coating iron patterns with, to prevent the sand from adhering thereto. To prepare the patterns, let them be well finished, and sprinkled with dilute acid; after which, when rusted in the atmosphere, they can be cleaned, heated, and the wax applied while hot, spreading it evenly over the surface with a brush. See Wax. Bell-founding.— The founding of bells is practically the same as for any other similar object, as pans, kettles, domes, etc. Large ones are usually made in loam by first striking a core, by means of a centre-spindle and sweep- board, the latter corresponding to the inner dimensions and form of the bell to be cast. When this has firmly set, another sweep-board answering to the outer contour of the bell is secured to the spindle, and a thickness of sand formed on the core; after which such ornamentation as may be required is secured thereon and a cope is built around, of such strength as the magnitude of the bell demands. The subsequent operations consist of lifting off the cope, taking away the thickness, finishing the moulds, drying, and closing in the pit as for any other casting. For the common run of bells a more ready way is pro- vided. These are invariably made in perforated cast-iron casings, which enable the founder to strike both core and cope separately, closing them together when dry, binding and casting without any subsequent labor of ramming. Bell-metal. 48 Bellows. The core-casing should be small enough to allow a wrapping of straw before applying the loam. The rope burns away and leaves ample room for contraction. See Casings; Kettles; Spindle. Bell-metal. — The alloys for large bells are now as various as those for small ones. It was formerly considered that copper 75, tin 25, was the best for all large bells, but it is claimed by many that copper 80, tin 20, is better. Many church-bells are successfully cast from either of the above proportions. The following proportions are about correct: Extra large bells: copper 16, tin 5. Church and large bells: copper 16, tin 4J. House-bells: copper 16, tin 4. Gongs, cymbals, etc.: copper 16, tin 3|-. Soft musical bells : copper 16, tin 3. Another composition introducing zinc and lead for church-bells is: copper 80, tin 10, zinc 5.6, lead 4.6. Clock-bells are also made from: copper 72.0, tin 26.5, iron 1.5. It will be seen that a small proportion of iron enters into the latter alloy; this is common with some founders, and zinc and lead form no mean proportion in the cheaper class of small bells. Lafond's mixture for small bells and piano-plates is: copper 77, tin 21, antimony 2. This alloy is yellowish white, and can be filed only with difficulty. A French bell-metal for hand, clock, and other similar- sized bells is : copper 55 to 60, tin 30 to 40, zinc 10 to 15. See Alloy; Brass; Japanese Bronze-work. Bellows. — These wind-machines for foundry use are somewhat after the pattern of those used in the home, except that they are usually provided with hinges and made strong. The common ones are used for blowing away superfluous parting sand off the patterns, and loose sand and blackening out of the moulds. Bellows for the bench Belt-core. 49 Bend pipe. are made without spout and somewhat shorter. Special bellows, for distributing blackening upward where it can- not be applied with the bag, are now made; as also are sprinkling-bellows for saturating the mould, where neces- sary, with water, etc. Belt-core. — It is common to call almost any descrip- tion of jacket-core by this name. See Jacket-coke. Belts for cores. — Leather-belting makes very reli- able and handy slings for lifting cores, but, owing to the very inferior means usually provided for binding the ends together when in use, very much of their reliability and usefulness is marred. If very thin steel ends are riveted on, all this annoyance is obviated. The steel, -^ inch in thickness, must be just as wide as the belt, and as short as is consistent with safety. The ends, being both turned with a very short " U," interlock each other. Bench-moulder. — A moulder, whose work being of a light description, can perform all the operations required for producing it in small wooden or iron flasks, standing up to his work at a suitably provided bench. See Snap- moulder. Bench-rammer. — A short wooden rammer used by the bench-moulder. It has just space sufficient between the butt and peen ends for the hand to grasp it. It is common for the moulder to use one in each hand. Bend-pipe. — A common name for all classes of curved pipes that are not distinctively elbows. The moulding of such pipes demands the attention of moulder and pattern-maker more than any other, simply because the constantly varying curves required make it impossible Benzine. SO Bin. to keep a stock of patterns on hand for the purpose. Hence, all manner of devices for moulding are resorted to, to save pattern- making, and, at the same time, obtain a good casting. See Jobbing-moulder ; Loam-pattern ; Touch. Benzine. — A limpid, oily fluid, resembling oil of tur- pentine. It is composed of hydrogen and carbon formed during the destructive distillation of coal. It readily dis- solves caoutchouc, gutta-percha, wax, camphor, and fats, and is useful for removing grease-spots from silk and woollen. See Tar. Beryl. — A mineral of great hardness occurring in green and bluish-green six-sided prisms. It is ranked among the gems, and is nearly identical with emerald, but is not so brilliant in color. It is infusible; with borax it fuses into a transparent glass. Its composition is : silex 68, alumina 15, glucine 14, lime 2, oxide of iron 1. See Em- erald; Precious Stones. Bessemer Steel.— This process of making steel was patented in 1856 by the inventor, Henry Bessemer, and consists in converting the pig-iron into malleable iron, as a preliminary operation, by blowing air through the mass of molted metal, previously introduced into a converter, until all the carbon, silicon, sulphur, and phosphorus has been burned out, and then converting this into steel by the addition of a small quantity of a peculiar cast iron of known composition, called Spiegeleisen. See Converter; Spiegeleisen; Oast Steel; Open-hearth Steel. Bin. — A wood or iron box for storing charcoal, sea- coal, lead, flour, or any other commodity used in the foundry. The providing of such repositories effects a considerable Binding- plates. 51 Bismuth. saving over the too common practice of having such things loose around the foundry in barrels. Binding-plates. — Thin plates cast by the loam- moulder to strengthen weak walls in copes and cores built with bricks. They are bedded, at intervals, on soft loam and the building continued over them. A slot or open- ing on one side allows of their being set without removing the spindle. If, when the slot is made, they should be considered too weak, extending lugs at that point will serve to clamp or bolt them fast, after they have passed the spindle and are bedded in place. For cores, the lugs are internal; for copes, external. They are often called building - rings. See Course ; Bricking - up ; Loam- moulding; Hoop-binder. Binder. — The name given to almost every device used in the foundry for binding moulds together before cast- ing, but in particular to the beams which rest over the copes of green and dry-sand moulds„as well as the covering- plates of loam-moulds, by which the upper portions of the moulds are made secure to the lower by means of clamps or bolts, in order to prevent any possibility of their being raised by the pressure of molten iron underneath them. See Pressure of Molten Metal. Bismuth. — A somewhat brittle metal, the color of which may be termed yellowish-white. It is a little harder than lead. Bismuth is found natural but impure in dif- ferent parts of Europe, in the veins or fissures of other rocks; also in combination with sulphur, arsenic, and oxy- gen. The pure metal is obtained by heating the impure metal, or native bismuth, in inclined cast-iron tubes, where the metal is volatilized and, the vapors condensing, run into receiving- vessels, and finally into moulds, where it solidifies with a crystalline texture. Bitumen. 52 Bitumen. At a high temperature, bismuth is slightly volatile and oxidizes rapidly. Its fusing-point is 507°, but it alloys with other metals to form fusible mixtures, which melt even below 212°. The specific gravity of this metal is 9.8. The fusibility of other metals is increased by bismuth, and its peculiar property of expanding while cooling makes it highly valuable as an ingredient in type-founders' alloys. A slight addition of mercury imparts greater fusibility to bismuth alloys. Alloys containing bismuth should always be cooled quickly, to prevent the separation of bismuth. Gold alloyed with bismuth forms a brassy composition of a brittle nature, and the ductility of gold is impaired even by its fumes. It is seldom that bismuth is employed alone in the arts, but it forms an important ingredient in many mixtures for solder, type-metal, fusible alloys, etc. Bismuth is separated from lead by dissolving the mixed metal in nitric acid; add caustic potash in excess, and the: oxides of bismuth and lead will be precipitated, but the lead oxide will be at once redissolved by the alkali. The oxide of bismuth can then be separated by filtration, washed, and ignited. See Solders ; Type-metal ; Fusi- ble Alloys; Separating Metals; Expanding Alloys. Bitumen. — Besides coal there is found in the earth a class of inflammable bodies— liquids, semi-liquids, and sol- ids — which possess properties very similar. The purest and most fluid of these hydrocarbons is naphtha ; when of the consistence of oil it is termed petroleum; slightly thicker it is pitch; after which we have elastic bitumen, and in its hardened state it is called asphaltum. Naphtha dissolves bit-um'en and caoutchouc. See Petro- leum; Asphaltum. Bituminous Coal. 53 Black Lead. Bituminous Coal.— See Coal. Black-flux.— See Flux. Blacking. — A general name for all classes of carbon- facings used in foundries. See Facing; Black Lead; Charcoal; Graphite. Blacking-bag. — A coarse linen or worsted bag to hold charcoal-dust or other facing, and by means of which to distribute the same evenly over the surface of green- sand moulds by a process of shaking. The loose dust is afterward pressed close by returning the pattern, or with the moulder's tools. See Facing; Printing. Black Lead. — The name commonly given to plum- bago, or India-silver lead-facings. It is called "India silver " because it is mined in India, on the island of Ceylon, and because it yields a polish of a silvery tone. The Jos. Dixon Crucible Company classify the several kinds as : Plumbago-facing for common work ; German or Bo- hemian lead for flat moulding; Ex, Ex, plumbago-facing for stove-plate, printing and copying presses ; India-silver lead for light and ordinary job-moulding ; " XX," plumbago for heavy cast-iron and steel castings; and Founders' core-wash for cores, loam, and dry-sand work — at prices from 10c. to 3|c. per pound, in the order given. One kind works with dry sand, and is used as a wash ; another works with green sand, and through a shake or blacking-bag; still another, with green sand, to be laid on the surface with a brush. Some facings require, for per- fect lines, a little dusting of powdered charcoal. Some brands will slick with the tools ; others not — making it necessary for the parties ordering these facings to specify what use they intend to put them to. Such kinds as Black Sand. 54 Black Varnishes. admit of easy slicking on green-sand moulds are the most useful ; as when this operation is properly done with good material, it will neither burn nor run before the molten metal, but adhere firmly to the sand surface, causing it to part clean from the casting, giving it a uniform bright color. See Facing ; Graphite. Black Sand is sometimes termed "old sand," and is the sand which constitutes what is called the foundry floor. When first introduced into the foundry the new sand is usually of a yellow or brownish color, sometimes red ; but by subsequent use for casting purposes, it be- comes burnt, or " old." The facing mixtures, containing sea-coal dust, is gradually insinuated among the floor- also ; these, along with the constant use of charcoal and lead-facings, cause the change in color of the original sand. For all parts of thin castings, which are far removed from the gates, this old sand, if fine originally, is to be preferred as a facing, because the constant burning to which it has been subjected has eliminated all clayey and other deleter- ious ingredients ; thus forming a surface upon which the molten iron will placidly rest free from the disturbing in- fluences of the gas-producing substances ordinarily found in new-sand. See New-sand ; Facing-sand ; Facing. Black Solder. — Copper 32, zinc 32, tin 4. See Sol- ders. Black Varnishes.— For patterns, alcohol 1 gall. ; shellac 1 lb. ; lamp-black sufficient to color it. Let it stand in a warm place, and stir occasionally. For castings, tar oil 20 lbs.; asphaltum 5 lbs.; powdered resin 5 lbs. Heat all togethe rin an iron kettle, and be careful to avoid ignition. See Varnishes. Black wash. 55 Blakney Cupola. Black- wash.— A refractory mixture for coating the surfaces of loam and dry-sand moulds and dry-sand cores, to protect the sand from burning by the interposition of a coat of carbon between it and the molten metal. The compositions for this purpose are various, but the principal ingredients entering therein are charcoal-dust, silver lead, mineral, and hard Lehigh blacking ; these, in varying proportions, are mixed with thin clay-water to a suitable consistency and applied with a swab or brush. See Facing. Blakney Cupola. — The Blakney cupola consists principally of a system of tuyeres, by which, it is claimed, the air is so distributed or projected into the furnace as to produce a uniform heat, giving the iron a uniform strength for all kinds of castings. The features peculiar to the above furnace are as follows: The introduction of a combination of curved tuyeres or chutes placed upon the wall or lining of the cupola, and forming a part of the wall, a proper distance from the bottom and nearly surrounding the inner and outer sides of the wall. The tuyeres are made of cast iron and in sec- tions for convenience of handling. A blank space is left in the rear of the cupola two feet wide, through which the slag is blown, if required. A chamber or base extending around the cupola in- closes the space in which the air is conducted to the tuyeres. The bottom of this chamber, made irregular in form, hollows at suitable intervals to allow the metal to flow to the escape openings, in case it overflows through the tuyeres. The openings are closed with fusible plugs of lead or other material to be melted out by the molten metal. The blast is conducted to this cupola through one pipe, and, striking the blank space sidewise in rear of chamber, Blast 56 Blast gates. passes all around through the curved tuyeres into the centre of the furnace, the blast striking into the cupola every J of an inch horizontal, and 3f inches perpendicu- lar, or according to diameter of cupola. As a producer of a uniform grade of iron for the purpose of casting car-wheels it is just what is needed for the differ- ent grades of iron to prevent chill-cracking. This cupola, with its many superior advantages, has also rows of shelves bolted to the shell four feet apart up to the top of the charging-door, so that it will not be necessary to tear out any of the lining except that which is burned out. Blast is air forced into a cupola or furnace by a blow- ing-engine, blower, or fan for the purpose of increasing combustion. If heated it is then called hot blast, and cold blast when it enters the cupola or furnace direct from the atmosphere. See Cupola ; Blowers ; Blast-pipes. Blast-furnace.— See Smelting-furnace ; Cupola ; Cast Iron". Blast-gates. — The apparatus for opening and closing pipes supplying blast to cupolas, furnaces, etc.; for use also in exhaust-pipe systems where shavings, dust, smoke, and the like are to be removed, or for regulating the distribu- tion of heated air. The lever style of blast-gate can be readily manipulated by cords, and is very convenient in cases where it cannot be reached otherwise. The slide style of blast-gate is per- haps as common as any. These should always be made of metal and kept clean ; otherwise they become troublesome and inefficacious. It is very important to know that the use of blast-gates to close pipes, when not in use, insures a great saving of power, as a blower requires far less power to drive it with closed connections than with open ones. Blast gauge. 57 Blast pipe-. Blast-gates are furnished by the manufacturers in sizes from %i inches to 30 inches, small sizes being made in com- position and the larger ones in iron, and these are always to be preferred to such as'are usually provided by the foundry tinker. See Cupola; Blast-pipes; Blowers. Blast-gauge is an apparatus to be attached to the wind-box of a cupola for indicating the pressure in blast- pipes. They are of simple construction and may be pur- chased from the makers at prices varying from $10 to $15, according to size and degree of finish. Ordinarily, the blast- gauge consists of a siphon-tube with equal legs, half-filled with mercury, one end entering the wind-box, the other be- ing open to the atmosphere. A stop-cock may be provided between this gauge and the wind-box, so that it may be shut off at pleasure. When the stop-cock is open, the blast press- ure acting on the mercury in one leg of the gauge presses it down, and the mercury in the other leg rises. The dif- ference between the two columns is the height of mercury, which corresponds to the excess of the pressure of blast in the wind-box above the pressure of the atmosphere ; or, in other words, to the effective pressure of blast in the blast- pipes. If 16 ounces be allowed for every 2 inches of the length of this column, or 1 ounce for every £ inch, the effective pressure of blast, in ounces per square inch, is thus obtained. See Cupola; Blast-pipes; Blowers. Blast -pipes are conducting-pipes from the blower to the cupola. These should always be made of iron and perfectly air-tight, and sufficiently large to convey the air without undue loss by friction. When the pipes are too small, a greatly increased velocity is required to discharge a given amount of air, with a larger proportional increase of fractional surfaces. All turns or elbows in conducting-pipes are objectionable Blast Pressure. 58 Blister. in the extreme, and should as much as possible be avoided, as from this cause the direction of the current is changed and the friction greatly increased. Air moving through blast-pipes expends a portion of its force in the friction of its particles along the sides of the pipes, with a consequent reduction in the pressure. In many cases the blower may be condemned as ineffi- cent when the pipe itself is the real cause of the trouble by reason of its too small diameter, its great length, or the number of bends or elbows it contains. The diameter of the blast-pipe should always be increased in proportion as the length is increased. The main blast-pipe for cupolas 24 to 29 inches diameter should be not less than 10 inches diameter, 30 to 33 inches, 12 inches diameter ; 34 to 39 inches, 14 inches diameter ; 40 to 45 inches, 16 inches diameter ; 46 to 51 inches, 18 inches diameter ; 52 to 57 inches, 20 inches diameter ; 58 to 70 inches, 22 inches diameter, and 24 inches for cupola's over 70 inches diameter. See Cupola; Blast; Blower; Combustion. Blast Pressure. — The blast should always be deliv- ered at a pressure sufficient to force its way freely through the whole contents of the cupola, and this is effected in cupolas from 20 to 80 inches diameter by a pressure of from 5 to 16 ounces per square inch. See Cupola; Charging the Common Cupola; Blast-pipes. Blister. — A cavity or hollow usually found in the upper surfaces of castings. They are imprisoned gases, which, having no means of escaping before the metal con- geals, arrange themselves in various sizes and shapes under a thin film of metal. They are found sometimes on the top side of pipes and columns, and in this case may be caused by the steam from a damp core, which, not having Blistered Steel. 59 Blistered Steel. a ready means of escape through the vents, finds its way into the mould. Another fruitful cause of blisters is rusty chaplets and studs, which give off considerable gaseous compounds as the rust decomposes. Blisters are almost certain to ensue when a green sand surface, core, or cope is too damp or wet in spots. Should there be no vents at that particular part to lead away the steam as fast as it generates, it must inevitably find its way into the mould, the result being blisters. Sometimes blisters are caused by the sulphurous gas con- tained in the iron itself, which, if it once enter the mould, acts exactly like the gases we have noticed above. Such gas as may be mingled with the iron will naturally ascend to the top if the mould's formation is favorable to its rapid transit in that direction; but, should it be otherwise, the probabilities are that it will be found imprisoned at whatever part of the mould it happened to be when the latter had received its fill of metal. Eemote risers do not in the least affect this phenomenon, as the currents of metal leading thereto may, and usually are, far removed from the already formed blisters in congealed parts of the casting. In- creased pressure will assist to force mould-gases out at the legitimate vents, but will render small help to expel such as may be contained in the metal itself, when the ordinary processes of moulding is employed. See Venting ; Pressing Fluid Steel; Eust; Paste. Blistered Steel. — A remarkable modification of iron intermediate between cast and wrought iron, containing less carbon than cast iron, but more than wrought (about 1| per cent). It is made by imbedding bars of best wrought iron in powdered charcoal in boxes or sand- furnaces which exclude the air, and heating intensely for a week or ten days. The steel, when withdrawn, has a peculiar, rough, blistered appearance, and for Block moulding. 60 Blower. this reason is called blistercd-steel. See Cementation ; Cast Steel. Block-moulding. — A device for producing thin, delicate castings, by first obtaining correct impressions in plaster of cope and nowel side of the pattern, upon which the respective parts are rammed separately in flasks which fit interchangeably. By this means all the moulds are exact impressions of the original pattern, as all danger of ramming out of shape is obviated. The match-parts and flasks being all interchangeable, there is no possibility of error. See Plate-moulding; Match-part. Block-print. — A large core print on a pattern, the impression of which receives a core containing some part of the mould, which if moulded from the pattern would require much more time, besides superior skill to per- form it. The core is termed a block core. See Core- print. Blower. — The name now applied to designate almost all descriptions of machines for creating an artificial cur- rent of air by pressure. It is claimed for the positive press- ure-blowers, now in constant use, that they measure and force forward at each revolution a fixed quantity of air, whether the pressure be high or low or the speed fast or slow; and the amount of air delivered can be accurately determined and controlled, and the exact quantity neces- sary, to effect the perfect combustion of a given amount of fuel at a given time supplied with perfect certainty. The blowing-engine or piston-blower also gives a forced blast, but it is not so good for the cupola as the positive blower, because the blast produced is irregular and comes in puffs with every motion of the piston, making it neces- sary to provide a large receiver to equalize the blast. This Blowholes. 61 Bogie. is, of course, both expensive and bulky. This class are sometimes called cylinder-blowers. The common fan-blower, a rotative blowing-machine, consisting of vanes turning upon an axis, has nothing posi- tive in its operation. The wings merely beat the air, im- parting a momentum corresponding with the velocity, but, as resistance is opposed to the blast, the volume is dimin- ished in the ratio of the resistance till a point is reached where the momentum and the resistance are equal, when no air whatever is discharged; but the fan-wheel continues to revolve in the case with great rapidity, absorbing a large amount of power, but doing no work at all. See Cupola; Blast; Combustion. Blow-holes. — Another name for blisters, but more correctly meaning' such holes as are further removed from the surface, or, perhaps, entire holes from the sur- face down; while a blister is so called because of the thin skin of metal which covers the hole. See Blister; Vent- ing; Paste. Blowing. — The rushing, roaring noise created by the forcible ejection of gases at the runners and risers when the vents are insufficient to carry them away, or are acci- dentally choked, is by the moulders termed "blowing." See Venting. Board. — An abbreviation of sweep-board. See Sweep- board. Bod-stick. — Another name for bott-stick. See Bott- stick. Bogie. — The name sometimes given to swivelled trucks and carriages used about the foundry or forge. Bog-iron Ore. 62 Bott-clay. Bog-iron Ore occurs chiefly in allirvial soils, in bogs, meadows, lakes, etc. It is a mineral of very variable composition, but regarded as consisting essentially of per- oxide of iron and water — peroxide of iron 60 per cent, water 20 per cent. Phosphoric acid is usually present in quantities varying from 2 to 11 per cent ; silicic acid, alu- minia, oxide of manganese, and other substances which seem accidentally present make up the rest. See Ores. Boiled Oil.— See Oils. Boiler-moulding is almost a distinct class of moulding, belonging to what is denominated holloio-ware ivork, although the larger description of boilers are some- times moulded in loam after the manner of kettles. See Hollow- wake Moulding ; Kettles. Boiling-point. — See Ebullition. Borax is procured by heating boracic acid with car- bonate of soda, the carbonic acid being expelled and the boracic acid taking its place. This salt has an alkaline taste and reaction, and possesses the property of dissolving many metallic oxides; hence its use as a flux in the weld- ing of metals. It dissolves off the coating of oxide formed w T hen they are heated, thus presenting a clean surface. See Flux; Solders. Boshes. — That part of a cupola immediately above the tuyeres. In large cupolas and blast-furnaces this part is gradually contracted from the widest part to the hearth, and the bricks used for this purpose are distinguished as bosh-bricks. See Cupola; Water-boshes. Bott-clay. — The clay used for stopping up the tap- hole in the cupola. Any good, ordinary clay will answer Bott-stick. 63 Bott-stick. for this purpose, but it requires more than ordinary care to bring it to the right condition for effective use. If too soft it is impossible to fill the hole with a firm ping, and if too hard it refuses to yield to the form of the hole, so that in either case there is dauger, because, as the bottom fills, the pressure increases and the imperfect plug is forced out. Besides being of the right consistency, there should also be mixed with it a quantity of sea-coal; this prevents in a large measure the sputtering usually attendant upon the use of the raw clay. The operation of tapping is ex- pedited also by this admixture of sea-coal, as it prevents to some exten tthe clay from baking hard, and for this reason is more easily picked out with the tapping-bar. See Bott-stick; Tappixg-bak. Bott-stick, sometimes called a "bod-stick," is the tool used by the cupola-man for plugging the tap-hole with clay after sufficient or all the iron has been allowed to run from the cupola. It may consist of a long iron rod about | inch diameter, one end of which is formed into an eye for ease in handling, and upon the other is forged a flat button, about 2 inches diameter, made with a corru- gated face in order that the clay bott which is pressed upon it may adhere thereto. For " stopping-in " over- large ladles it is almost necessary to have an iron bott- stick, but when small ladles are in use, and the hole is opened frequently, a long wood shaft may be substituted for the iron rod by either forming the button on a spike and driving it in the end, which is prevented from split- ting by an iron band, or it may be formed on an iron socket made to receive the end of the shaft. The wood ones are much lighter and easier to handle than the iron ones. To use the bott-stick properly, see— first, that the button is cold and wet, a pail of water being kept near by for the purpose ; second, that the clay bott is pressed Bottom-part. 64 Brass. firmly down upon it and worked with the hand into the form of a cone; and thirdly, that the back-hand be slightly raised, pressing the clay into the hole from the upper side. By this means whatever commotion takes place when the molten iron touches the wet clay is in the immediate vicinity of the tap-hole in a downward direction, thus avoiding all the unpleasantness and danger caused by the spray of metal, which is thrown in all directions when the bott is thrust carelessly into the hole with the stick held in a horizontal position. See Bott-clay. Bottom-part. — The nowel or drag. See Flasks. Bottom-plate. — See Foundation-plate. Brass. — A yellow alloy of copper and zinc, much used for furnishing and decorating, as well as for parts of machinery. It is common to include other alloys, as cop- per and tin in this classification ; these, however, are not brass, but bronze, and will be found described under that head. When brass is manufactured on a large scale, it is usually made to contain: copper 2, zinc 1; but the alloys must necessarily vary according to the purposes for which they are intended. If more than ordinary tenacity is re- quired the alloy must consist of about : copper 16, zinc 4; but if a hard, brittle alloy possessing reduced resisting power is desired, the zinc may be increased to equal quan- tity with the copper, or even beyond that where, at copper 1, zinc 2, the yellowness ceases entirely, and we have a brilliant bluish-white alloy of so crystalline a nature that it may be crushed in a mortar. The method of manufacturing brass in large quantities is to heat in crucibles a mixture of calamine, or carbonate of zinc, charcoal, and scrap, or grain copper, in the propor- tions thus : calamine and charcoal 3, copper 2.. The; Brass. Co Brass. action of the white heat reduces the calamine, and sepa- rates the zinc, which, combining with the copper, forms a brass consisting of copper 2, zinc 1. Common ingot brass is made by the simple fusion of copper 16, zinc 8 ; but, owing to the volatility of zinc, the resultant proportions of the alloy are seldom to be relied upon, and calamine brass is preferred. The vapor of the zinc-ore by the latter mode combines more intimately with the copper. Yellow brass for filing and machining ranges from : cop- per 16, zinc 4, to copper 16, zinc 9. Up to this propor- tion brass remains very ductile and malleable ; beyond it, the crystalline nature asserts itself in proportion as the zinc is increased. Copper and zinc mix in all proportions, but it requires the greatest care in mixing to obtain the proportions aimed for, owing to the zinc's volatility, as before stated. With reference to the color of brass alloys, copper-red gives place to yellow at copper 16, zinc 4, and maintains about the same hue up to copper 16, zinc 10 ; when it gradually becomes lighter up to copper 1, zinc 2 — which as before stated, is a bluish-white with a brilliant silvery lustre when polished. The fusibility of brass increases with the zinc ; so that the metal from copper 16, zinc 7, up to copper 16, zinc 15, is eminently adapted for running a large class of furnish- ing and decorative-work ; but before such brittle metal as this is subjected to the various processes of cleaning, dip- ping, lacquering, and bronzing, it is invariably annealed. The specific gravity of brass is greater than that deduci- ble from the specific gravity of the metals composing it. The brass for ornament is prevented from tarnishing by lacquering and bronzing. The former consists of coating with shellac in spirit, with some coloring ; the latter pro- cess being effected by the application of metallic solutions, after a course of cleansing in acids. Brass. 66 Brass from copper 50, zinc 50, to copper 63, zinc 37, may be rolled into sheets and otherwise worked when heated to a red heat; but, according to Muntz, copper 60, zinc 40, is the best proportion. When brass is made for this purpose it is cast into ingots, then heated and rolled. Brass is made hard by hammering or rolling, but its temper may be again drawn by heating to a cherry-red and plunging it in water. Copper-castings are, to a great extent, freed from poros- ity or honeycombing by the addition of from i to 1 ounce of zinc to 16 ounces of copper. The following compositions are alloys of copper and zinc only, which constitute true brass: COPPER AND ZINC ALLOYS. Copper castings are made solid by Brass gilt for jewelry, etc., bronze color , Heavy Machinery bearings , Sheet brass, red Tough engine brass Brass to imitate gold Bristol brass, solders well Brass wire Brass castings, ordinary Muntz metal (one extreme) " (" " ) Pale-yellow brass for dipping (spelter solder for copper or iron) Another dipping-brass Spelter solder for brass Speculum metal Mosaic gold Copper. Zinc. 16 itol 16 1 to H 32 1 16 3 20 3 16 3* to 4 16 6 16 7 16 8 16 9 to 10$ 16 16 16 12 16 14 16 16 100 18| 32 3a As a supplement to the above, the author appends the following list of mixtures, which are largely original, and of known excellence for the numerous purposes mentioned: Brass. 67 Brass. MISCELLANEOUS MIXTURES 'FOR GENERAL MACHINERY PURPOSES, ETC. Soft Machinery brass Large steps or bearings (common). " " " (good) .. " " •' (best).... Small " " " Ordinary D valves Extra large" " Delivery valve-lids Large bells Small clock-bells General machinery brass " (good) " " " (collars, etc.). . Large cocks Small '« ...., Common " . Yellow brass *• " (good) " (better) Brass for cutting-wheels Roller brass Large copper rivets Small " " Lathe-bushes Pnlley-blocks Wheels Gun-metals Connecting-rod steps Valve-spindles , Valves and seatings Piston-rings Brass to expand by heat equal with iron , 4 2 a* U 2 44 u 2 2 1 9, 5 2 1 i" * U l U 3 1 15 15 For further information on this subject, see Alloy; Brass-purnace ; Brass-moulding; Brass-tempering; Brass-scrap; Bells; Bronze; Cementation; Copper; Sheathing-metal ; Solders; Lacquering; Zinc; Gas- blast Furnace; Portable Furnace; Hard Alloy. Brass-furnace. 68 Brass-furnace. Brass-furnace. — The common method of erecting brass-furnaces for melting in crucibles is to build them on one side of the shop. The insides are formed within cast or wrought iron casings, from 18 to 20 inches diameter and about 36 inches high. These are ranged over the ash-pit, and the air is supplied through gratings set even with the foundry floor, through which the air finds its way to the pit below. Usually the tops of the furnaces stand about 9 inches above the floor and are covered while in operation with a cast-iron doomed door. The casings are fire-brick lined to a suitable diameter that will leave the requisite amount of fuel to surround the crucible. A small hole, about 6 inches square, is left near the top, which connects with the flue leading to the chimney. If a row of such furnaces are thus constructed, there should be a separate flue for each, so that one or more of them may be em- ployed at any time without any interference with the draft. The chimney in all cases should be a tall one to encourage the draft. Portable brass-furnaces, round and square, are now sup- plied by the dealers. They are simply an iron casing, com- plete in all respects, except the lining; can be located at any part of the foundry, and connected with the chimney. The Gas-blast Melting Furnace manufactured by the American Gas Furnace Company is now extensively em- ployed for all purposes of crucible melting. A positive air- pressure maintains perfect combustion of the gas, and clean- liness is secured by the entire absence of soot. The best results are attained in these furnaces by securing perfect combustion and by confining the space to be heated to the smallest possible limits consistent with convenience. These furnaces are made in sizes to suit Dixon's block cruci- bles from Nos. to 200; special fire-bricks being made for every sized furnace (see Gas-blast Furnace). Very fre- quently the cupola is employed when a large quantity Brass-furnace. 69 Brass furnace. of metal is wanted. A much better mode, however, is to provide a reverberatory or air-furnace in close proximity to the brass-foundry, or wherever it may be customary to cast heavy brass-work. The Garrett Furnace, a fire-brick construction after the manner of an air-furnace, is described by the inventor as follows : " In a shop where any considerable amount of brass is melted, the method of melting in a crucible is wasteful and expensive. The Garrett Furnace not only saves the cost of crucibles, but is also economical of metal, fuel, and labor, besides reducing the time of melting a charge from one half to two thirds. This furnace was especially designed for full gas, but with a slight modification of details it could be used with soft coal or crude oil as a fuel. There is a slant hole for charging coils of copper wire or material difficult to compress into a small space. Smaller pieces, bars, or plates are introduced through the charging- door. The bosh for the molten metal is located below the melting-chamber, being 33 inches wide by 18 inches high from the bed to the top of the arch, which is composed as shown, and has filling above and between it and the bottom of the charging-chamber, made of fire-clay and sand. The bed of the bosh is undulated being composed of a mixture of fire-clay and sand, which makes it as hard as a crucible and will last from two to seven weeks without repair, ac- cording to the work required of it. Below the bosh gas- flues are provided, two 6-inch by 6-inch for gas and two the same size and adjacent for air. The gas is brought to the gas-flues by two i inch gas-pipes having valves for regu- lating the supply, and passes along the flues to a combus- tion-chamber, 12 inches wide, 36 inches long, where it mixes with air, ascends and passes over the bridge, and is divided into two flames, one larger than the other. The large flame passes over the bosh to the flue, and the other Brass Mirrors. TO Brass Moulding. flame passes through the melting-chamber to the flue. Dampers are provided in the flues to regulate the supply of gas, or proportion it for either of the chambers as de- sired. One flue is 4 inches by 10 inches, and the other is 8 inches by 10 inches, both entering into a stack-flue 16 inches square. A door is provided to give access to the combustion- chamber and bridge, and another door, gives access to the bosh. See Brass; Portable Furnaces. Brass Mirrors. — These mirrors are of classical an- tiquity, and were made from an alloy known as speculum metal, which produces a very hard metal with great reflect- ing power; but it is now very seldom met with. A good speculum metal, very white and hard as steel, is composed of equal parts of copper and tin. Copper 7, tin 4, zinc 3, form an alloy of a light yellow color, possessing much lustre. This alloy is sometimes made from copper 2, tin 1, with the addition of T ^ arsenic. Lord Eosse's composition was: copper 252.8, tin 117.8. See Speculum Metals; Rosse's Telescope; Brass. Brass Mixtures.— See Brass. Brass Moulding. — So far as the actual moulding is concerned there is very little to distinguish it from the or- dinary course pursued for producing castings in iron. For the larger castings in dry-sand and loam, exactly similar moulds are made, but for the very light brass castings in green sand it is necessary to have a very fine silex sand, which contains a slight portion of clay. When the sand contains clay in excess it favors the production of the finest work; but there is always danger of blown spots when this is used, only to be remedied by drying the moulds, or introducing more open sand, to permit the gases generated at pouring Brass Scraps. < 1 Brass Scraps. to escape. It is not necessary to cast brass any hotter than will result in clear, sharp outlines in the casting. As a rule, most brass castings will be freer from honey- combs, if the metal is forced in at the lowest part of the mould, taking care that suitable vents are provided for carrying off the gas as it generates in the mould. The fact that all sands taken from the earth must con- tain more or less vegetable matter, which burns out as soon as the metal strikes it, making a rough and unfinished looking casting, has prompted some dealers to prepare a composition of minerals, crushed and put through a pro- cess known alone to themselves, where every trace of vege- table or any other matter not standing a high fire-test is extracted, the sand being usually ground and bolted. See Brass; Facikg-sand ; Rock-crusher. Brass Scraps. — Old brass, judiciously selected, may be made to do excellent service. As the regulation mixt- ures for the several articles made in brass are pretty much the same all over, it is a simple matter to make such choice from the old scraps as will almost answer present needs very often by making such additions as are necessary to bring the mixture up to the required standard in any of the metals which the scrap may be lacking in. Another important feature in using scrap-brass is to remember that, when it is melted over again, more or less of the zinc and lead oxidizes and wastes; this, of course, changes the original proportions, and must be made good by additions of the above metals. For old brass that has been remelted more than once, it is well to add 1 pound of lead to 16 pounds of scrap; a little less will do when the metal has not been recast. Brass borings and turnings may be melted with little or no waste by packing the crucible fall and hard, using a cover and luting it well. Add a little lead when melted. See Brass; Crucible. Brass-tempering. 72 Breast-hole. Brass-teinpering. — Brass containing the least zinc is the softest and most easily wrought but, with a pro- portion of one fourth, brass is still perfectly malleable when cold. Hammering increases or creates elasticity in brass, destroys its flexibility, adds considerably to its dur- ability, and imparts magnetic power. If it is desired to draw the temper again, heat to a cherry-red, and immerse the article in water. See Brass; Tempering. Brass to Dull.— See Dulled Brass. Brazing. — Soldering with an alloy of copper and zinc. This operation is usually confined to joining copper, zinc, and iron surfaces, and in order to effect a solid junction the surfaces to be united must be made clean and bright. The brazing alloy, after being granulated, must be wetted with ground borax and water and then dried, after which it must be strewn over the gap or crevice, or between the two pieces to be united, which are then exposed to heat until the solder flows between them. The solder may be rendered more fusible by the addition of a little zinc. See Soldering; Solders; Oast Iron to Braze. Breast-hole is the hole in front of the cupola, just back of the spout, at which place the tap-hole is formed. Much of the trouble caused by slag gathering at the tap- hole is attributable to the very careless manner in forming the tap-hole. Sand is used for this purpose without refer- ence to its refractoriness, the consequence being that the intense heat gradually melts it into slag, and it issues from the hole at every tap. If the heated fuel in front is made as level as possible, filling all the spaces with pieces of coke before the sand is introduced, and no more than about three inches of a well-dampened and refractory mixture be rammed therein, much if not all of the trouble from slag Bricks. to Britannia Metal. at that point will cease. See Cupola; Spout; Slag; Tap- hole. Bricks. — Good common bricks have about the follow- ing composition : silicia f , alumina \ 9 lime, magnesia, soda, iron, potash, and water being included in the other fifth. The American brick varies in size from 7f to 8 J inches long, 4 to 4 \ wide, and 2 J to 2 J thick. English bricks average 9 inches long, 4J wide, and %\ thick. A too severe fire in the kiln fuses the brick and causes hard clinkers ; on the other hand, insufficient burning causes a soft brick unfit for use. See Fire-brick. Bricking-up. — A relative term for bricklaying, and meant by moulders to imply the process of forming the containing- walls of a loam-mould. Bricks in this instance take the place of flasks, the needed rigidity being imparted by binding-plates which, if necessary, may be further strengthened by bolting the sections together. The sweep- board is the guide for laying, and the bricks are set apart for fine cinders to form passages for the gases. See Roughing-up ; Skinntwg-loam ; Sweep-board; Bind- ing-plates; Course; Filling-ln". Brimstone. — See Sulphur. Britannia Metal. — A tableware alloy, with some resemblance of silver. Articles made from this alloy were formerly made by stamping with dies, but this has been superseded by the more efficient method of spinning. One mixture for this metal is: brass 4, tin 4; after fusing add bismuth 4, antimony 4 — this composition to be added at discretion to melted tin. Another is to make up a hard- ening compound of copper 2, tin 1. This is made separate and used with other ingredients as follows: Broken Castings. u Brushes. BRITANNIA METAL. Best quality Good " Metal for casting spinning . . . registers .... spouts spoons handles pillars, lamps Tin. Hard- ening. Copper. 150 140 210 100 100 140 100 140 300 "i" 8 ■■•»•■ 3 3 4 ...... "k" 4 Anti- mony. 10 9 12 4 8 6 10 6 15 See Allots; Tin - ; Antimony; Copper; Spinning Metals; White Alloys. Broken Castings. — See Burning. Bronze. — A mixed metal, consisting chiefly of copper with a small proportion of tin, and sometimes of other metals. It is used for casting statues, bells, guns, and numerous other articles, in all of which the ingredients are of varying proportions. For a description of the various bronzes, see Aluminum -bronze; Phosphor-bronze; Manganese-bronze; Statuary; Bells; Deoxidized Bronze; Vinegar -bronze; Gun- metal, and other bronzes. Also, Copper; Tin; Zinc; Fontainemoreau's Bronzes; Japanese Bronze-work. Bronzing Liquids. See Stains for Metals. Brushes. — These implements are now made in infinite variety for foundry purposes. Among the number may be noticed the soft bristles for moulders' ordinary use; black- ening brushes of special manufacture for coating vertical moulds; flat English bristle for loam and dry-sand blacken- Buckling. 75 Bugs. ing; flat camelVhair for distributing dry lead on green moulds, as well as for the finer classes of loam and dry- sand finishing, and steel-wire hand-brushes for cleaning castings. An improved steel-wire brush is a rotary, one that may be revolved by power. Buckling. — The seamy, unsightly scars to be seen on some castings when too much slicking and too little vent- ing have been expended on clayey loam or sand. "When due attention to these shortcomings fails to work an improve- ment, it is evidence conclusive that more fire-sand is needed in the facing-sand. See Slickek; Scabbed Cast- ings; Venting; Ramming; Facing-sand. Buckle -chain. See Swivel-chain. Bugs. — The name given in some places to the small shot-scrap made in the immediate vicinity of the cupola, and along the track of the ladles during the time of casting. No description of scrap is so difficult to manipulate as this. If charged in bulk at the commencement, no end of trouble is caused through the accumulations of dirty slag left be- hind, and which, materially impedes the regular working of the cupola throughout the heat; whilst if it be used in small quantities with each charge, there is a possibility of more or less of the fine stuff falling through the openings and finding a lodgment near the tuyeres, or, what perhaps is worse, being carried past the melting-point unmelted, to be again resurrected by the tools of the machinist — a too frequent occurrence where such scrap is used indiscrimi- nately. The best method of utilizing this foundry pest is to choose a time when everything is convenient and before the last charge of good iron has got too low; charge the bugs along with a heavy proportion of some good softening pig or special compound, taking care that an extra charge Building-rings. 76 Burnt Iron. of fuel is used for the purpose. By running this mixture into pigs, to be remelted, there will be no risks taken, and all annoyances previously spoken of will certainly be ob- viated. See Cupola; Charging the Common Cupola. Building-rings. See Binding-plates. Bullet-mould. — This entire mould consists of a pair of hinged cheeks, with one or more spherical cavities reamed therein, connecting with an ingate through which the melted lead is poured. They must fit exceedingly close when brought together. Burden. — The burden in the cupola or blast-furnace is supposed to be light when the proportion of fuel to ore or iron is large. When the fuel is proportionately small in the charge, the burden is then called heavy. See Charg- ing the Common Cupola. Burning. — A phrase signifying brazing or mending broken castings by melting the joining edges and leaving the space filled with molten metal, which when set unites the parts. The common process consists of pouring a con- stant stream of hot fluid metal along the fissure or upon the surface until the parts are entirely fused, taking care to leave an excess of metal for subsequent chipping and trimming after it has become cold. See Brazing; Solder- ing. Burnt Iron is all such iron as may have been for a lengthened period subject to a heat somewhat below the melting-point, on which account it has become little better than an oxide of iron. Its color is of the various shades of red, such as may be noticed in burnt retorts, grates, fire- bars, etc. Iron of this description should be used sparingly Butt-rammer. 77 Calcareous Spar. along with a large proportion of high silicon pig, if used at all. Any attempt to reduce such iron without a considerable admixture of good softener is sure to result in pasty and sluggish iron accompanied by an extraordinary amount of slag, which plays havoc with the cupola. The great amount of waste which occurs in melting this class of iron is of such extent as to make the operation a loss almost every way. See Charging the Common Cupola; Cupola. Butt-rammer is usually a heavy rammer with a flat, round, or square face, forged or cast to a long rod or piece of tubing, with which to complete a course of ramming after the pegging-rammer has forced the soft sand well down on the course immediately underneath. See PEG- GING-RAMMER. c. Cadinium. — A somewhat rare metal found associated with zinc in nature, and is similar to that metal in its chemical relations. When exposed to the air it tarnishes. Cadmium is a lustrous bluish-white metal; melts and volatilizes at a temperature below redness, and if heated in the air it takes fire and burns to a brown oxide. See Zinc. Cage Iron. — A skeleton core iron, used for such cores as the jackets of cylinders, etc. See Skeleton Core Iron. Calamine. — A native carbonate of zinc, used in mak- ing brass. See Brass; Zinc. Calcareous Spar. — A carbonate of lime, occurring principally in grayish-white crystals. It is infusible, falls into quicklime before the blowpipe, and effervesces with Calcination. 78 Caliper. acids; its composition is lime 57, carbonic acid 43. This mineral is of universal occurrence, and sometimes it is found tinged with various shades of color, owing to the presence of manganese, iron, and other impurities. Calcination. — The process by which some bodies by the action of fire are reduced to the condition of a calx or cinder. Most of the metals can be reduced, to this condition, which renders them easily reducible to powder. By subjecting ores to the action of the fire the volatile parts are driven off, and the water of crystallization dissi- pated. By this process marble is converted into lime by expelling the carbonic acid and water, and the same may be said of borax, gypsum, alum, and other saline sub- stances which are deprived of their water of crystallization by the process of calcination. There is a difference be- tween calcination and oxidation, fire being a necessary agent in the former case, while metals may be oxidated by acids, heat, or exposure to the atmosphere. See Weath- ering Ores; Kiln. Calcium is a light yellow metal, somewhat harder than lead — very malleable; melts at a red heat and oxidizes in the air. It exists in abundance in limestone, fluor-spar, and gypsum. See Lime. Caliper. — Caliper compasses are very serviceable tools in a foundry doing general work of a superior order. No consideration of false economy should be tolerated that does not furnish ample means for obtaining correct meas- urements. These tools especially should be of a reliable character. They may now be obtained in an endless variety of styles and finish from the supply dealers throughout the country. See Gauge. Camel's -hair Brush. 79 Cannon. Camel's-hair Brush. — An excellent tool for giving the final touches to finished dry-sand and loam work, as also for use on green-sand surfaces with dry lead. For these purposes they should be double thickness and brass- bound. They are sold by the width at from thirty-five to forty cents per inch. See Bkushes. Candle. - See Oils. Can-hooks. — This excellent device is improperly called " cant-hooks " in some localities. It consists of a double chain, rope, or bar-sling attached to a ring, with ends slightly hooked for gripping the underside of a flange or projecting lug. Very useful for taking a balanced lift where such practice is convenient. See Slihgs; Chain". Cannel-coal. — A dense, compact coal of a highly bituminous nature, used largely for making gas. See Coal; Fuel; Petroleum. Cannon. — A long cylindrical tube for throwing pro- jectiles by the explosion of gunpowder. The date of the in- vention and the name of the inventor are unknown. It is certain that King Edward employed cannon at the battle of Cressy, A.D. 1346, but records are extant showing that they were known in France as early as the year 1338; and Isaac Vossius asserts that they were used in China seventeen hundred years ago. The earliest cannon were made by hooping iron bars, or of sheets of iron rolled up and fastened together. These cumbersome machines were used for throwing large stones in the manner of the an- cients. These were gradually supplanted by brass cannon of much smaller calibre, which threw iron and lead balls; they were first cast of a mixture of tin and copper, which was naturally called gun-metal, but subsequently cast-iron Caoutchouc. 80 Carbonic Acid. guns came into use on account of their being so much cheaper. See Ordnance. Caoutchouc— See Kesin; India-rubber. Capacity of Ladles.— See Ladles. Carbolic Acid.— See Tar. Carbon. — A simple combustible, which constitutes a large proportion of all animal and vegetable substances. We are familiar with it in the diamond, and the various kinds of charcoal, mineral coal, lampblack, etc. Carbon unites with all the simple combustibles. With iron it forms steel and plumbago, and with copper it forms a car- buret. The diamond is the purest form of carbon. See Diamond; Graphite; Charcoal; Cast Iron; Steel. Carbonates. — Compounds of carbonic acid with sali- fiable bases, composed either of one prime of acid and one of base, or one of acid and two of base. The former are carbonates, the latter bicarbonates. Carbonic Acid.— This acid is composed of oxygen 72, carbon 28 ; specific gr. 1.529, air being 1.000. All forms of carbon when burned in the air unite with oxygen to form carbonic acid. It constitutes 44 per cent of lime- stone. A cubic inch of marble yields four gallons of the gas. Under a pressure of 36 atmospheres at 32° carbonic acid shrinks into a colorless liquid lighter than water. It does not resume the gaseous state when the pressure is re- moved, but evaporates with great rapidity, one portion ab- sorbing heat from another, and thus freezing it into a white substance like snow. Unlike other acids, it does not unite with water to form a definite hydrate. It is anhydrous in Carbonic Oxide. 81 Carriage. all the three states — gaseous, liquid, and solid. It is incom- bustible, and a non-supporter of combustion. See Gases; Liquid; Solid. Carbonic Oxide.— See Oxide Carbonic. Carbonize. — To convert into carbon by combustion, or the action of fire, or any other means, as the carburiza- tion of malleable iron by the addition thereto of carbon, through solid or gaseous carbonaceous matters. See Cem- entation; Crucible Steel. Carburet. — The union of carbon with a base, or a combination of carbon with any of the simple substances. It is more commonly termed a carbide. Card-moulding. — See Plate -moulding. Carnelian. — A semi-transparent mineral only distin- guished by its colors (the various shades of red) from agate, jasper, etc. Finest specimens of this mineral come from India; it has a glimmering lustre and is sometimes found a dark blood-red, passing into a greenish-brown. It is in- fusible. Its composition is silex 94, alumina 3.5, lime 1.5, oxide of iron 0.75. Carnelian was much preferred by the ancients for engraving upon. See Precious Stones. Carriage. — An iron vehicle to run on tracks, which ought to be laid convenient to one or more of the foundry cranes, and from thence inside the oven or stove. In plan- ning carriages for this purpose strict attention should be given to local requirements, not to any particular one that may have been seen or heard of elsewhere. For example : Would it be best to make a perfectly flat table ? and, if so, how high, and how large in area? Or, should it be provid- ed with fixed or adjustable racks ? If so, how high and in which direction, to be most convenient for passing the Carrying bar. 82 Car- wheel Founding. cores ? Again, would it be of service to attach taper-sock- ets for loam-work spindles, with the view of building on the carriage direct ? Finally, is it possible to so combine these or other qualities as to make it the best and most convenient carriage possible for either special or general purposes ? See Oven ; Spindle. Carrying-bar. — A stout wooden or iron bar, about 30 inches long, having a depression in the middle. By means of this contrivance, two men stand or walk side by side, supporting the single end of a shank-ladle between them. See Shank; Ladle. Carving. — By this term we generally understand the art of cutting figures and designs in wood with suitable sharp instruments made for the purpose. Cutting de- signs in stone is termed sculpture, and similar operations on metals is called chasing. Patterns for decorative, archi- tectural, and other castings, which were at one time the productions of the wood-carver, are now accomplished in shorter time and at less cost by the modeller. See Mod- elling. Car-wheel Founding. — The manufacture of car- wheel is a special branch of foundry industry, which, in all of its varied phases, demands more than ordinary attention to make good wheels at a profit. The processes of their manufacture are substantially as follows : First, a good, substantial wood pattern, or better, an iron one, with iron core-boxes in which to dry the cores. Second, a set of flasks consisting of cope, with bars to fit one inch clear of the pattern ; drag, with separate perforated bottom-plate ; and an intermediate chill 4 inches thick, for chilling the tread, with lugs and pins to match both upper and lower parts, and trunnions for reversing. Third, moulding and casting. Fourth, lifting from the sand red hot, and lower- Car- wheel Founding. 83 Car-wheel Founding. ing into the annealing-pit, where the wheel cools gradually in about three or four days, when it is taken out, cleaned, tested, and if found sound in every particular, is pronounced a chilled car-wheel. The " Barr " contracting car-wheel chill is described in The Machinery Moulders' Journal as follows : The ring, which constitutes the ordinary chill, is divided into 96 sections by radial divisions. The sections or blocks are held in position by an outside ring, which is capable of being expanded or contracted, thus causing the blocks composing the chill to be moved, radially, outward or in- ward. By this means the expansion which occurs in the ordinary chill is entirely prevented, and the inward radial motion of the chill-blocks is such as to extend the time of contact between the chill and the contracting-wheel within, until nearly the full effect of the cooling influence of the chill is obtained. The expansion and contraction of the outside hollow retaining-ring is effected by introducing steam or water. The operation of the chill is as follows: When the moulder is nearly ready to pour his metal, steam is turned on through the outer ring, causing it to expand, and carry- ing with it the chill-blocks, thus increasing the diameter of the chilling surface. When the chill becomes so warm that you can barely lay your hand upon it the steam is then turned off. The iron is now placed in position to pour, and the moment the iron enters the gate or pouring-head, cold water is passed through the ring which causes a con- traction of the outside hollow sustaining ring and a conse- quent decrease in diameter of the chilling surface. This chill has been in use in our foundry for the past year, and during that time our loss from chill-cracks and other causes has been ^ of 1 per cent, while in the old- style chill the loss has been from 3 to 6 per cent. There is in fact an entire absence of chill-cracks, rough Case-hardening. 84 Case-hardening. tread, and sweats, and the presence of slag almost entirely prevented. There is a decided improvement in the depth of white iron and its uniformity around the tread; the average variations in the white iron being about -£ w inch, while in the old or solid chill I have known it to vary as much as f to $ inch. The quality of gray iron, with its freedom from slag or imperfections, and the general strength of the wheel is enhanced by hotter and faster pouring, which is made possible by the use of this chill. With the old or solid chill the time consumed in pouring a chill is about twenty seconds, and with the contracting chill nine to twelve seconds. There is only one objection to the Bar contracting chill, and that is the small ridges formed by the spaces between the chill-blocks. These we are compelled to grind off with an emery-wheel. This labor can be lessened by filling these crevices with sharp sand. Case-hardening is the term applied to the process of converting the external surface of articles or masses of iron into steel, with the view of combining the hardness of the latter with the toughness and comparative cheapness of the former. This may be done by placing iron articles (finished, but not polished), along with animal carbon, as hoofs, leather, skins, etc., that have been partly burned to admit of being powdered, into an iron box, well luted, and subjecting them to a red heat for about half an hour, or even more, according to the depth of hard surface needed, after which plunge the contents into water. Oast iron may be hardened on the surface by first bring- ing to a red heat and rolling in a mixture of saltpetre, powdered prussiate of potash, and sal-ammoniac in equal proportions, after which immerse in a bath of water which contains in each gallon, sal-ammoniac 4 oz., prussiate of potash 2 oz, Casings. 85 Castings, To Galvanize. Small iron articles will be case-hardened by allowing them to remain 30 minntes in a fused liquid consisting of common salt 10, prussiate of potash 1, and subsequently plunging into cold water. An iron pot will serve to fuse in. Casings are perforated iron shells, provided with prickers for carrying the loam thickness, and with means for lifting and turning over the cope part. When the form of castings is favorable to non-interference with contraction, as in some sugar-pans, crystallizing-cones, and other kindred castings, both inside and outside moulds may be swept with the spindle, closed and cast, without any subsequent ram- ming in the pit which necessarily attends the ordinary methods. Cylindrical casings are equally as advantageous when the quantity of castings required will warrant the outlay for making them. See Bells; Kettles; Spindle. Cast. — A term used among fine-art workers, meaning impressions from sculptures, medals, and other delicate works of art; also, the taking of casts from the face and other natural objects. See Plaster-cast. Cast is a common term in the foundry; as, when a piece has been poured, it is said to be cast ; when a moulder has finished pouring as many moulds as constitute a day's product, he is considered to be cast off. Casting. — The finished or completed product in the foundry. The act of pouring metal into a mould is called casting the mould. Castings, To Bronze.— See Stains foe Metals. Castings, To Galvanize.— See Zinc-coating. Castings, Weight of. 86 Cast Iron. Castings, Weight of.— See Weight of Castings. Cast Iron. — Cast iron is the product of the iron smelt- ing-f urnace. Iron occurs in nature, almost universally, in a state of combination. The mineral masses which it forms with oxygen, carbon, sulphur, and the metals, and from which it is extracted, are called its ores. It is strongly magnetic, and rubs into a black powder. Magnetic iron ore (loadstone) is one of the richest ores of the iron, contain- ing 72 per cent of iron and 28 of oxygen. Specular or red iron ore is very hard, and sometimes presents a polished appearance, brown in color; but its powder is always red — by which means it may be distinguished from the magnetic oxide. This ore contains 63 per cent of iron and 36 of oxygen. Red hematite is much used, being very plentiful, as also is brown hematite, which is found in almost all parts of the world; it contains about 86 per cent of peroxide of iron to about 14 of water. Clay ironstone occurs amongst the coal measures, and contains only about 37 per cent of iron. Bisulphide of iron, or pyrites, occurs in large quanti- ties under different forms. Pyrites is prized chiefly as a source of other substances ; it is never worked for its iron. The richer iron ores yield a good iron by simply heating the broken ore with charcoal in an open fire with blast. The ore is deoxidized, or, in other words, deprived of its oxygen by the carbon of the fuel, and the reduced iron is gathered into a pasty mass called a " bloom," while the earthy impurities contained in the ore combine with a por- tion of the oxide of iron to form a slag. Very much of the iron is, by this method, lost in the slag, and there is also a great waste of fuel; but the method is so simple that it may be practised by people possessing little knowledge of chem- istry, and for this reason it is no doubt the oldest method of extracting iron from its ores. The metal is not usually obtained pure in the extraction Cast Iron. 87 Cast Iron. of iron from its common ores, as it contains more or less carbon, which imparts to it a fusible nature; for which rea- son iron in this state is designated " pig iron," or cast iron. The processes connected with the reduction of the ores con- sist of, first, calcining or roasting (this is done to expel carbonic acid, water, sulphur, and other volatile ingredients of the ore); secondly, the reduction of the oxide of iron to the metallic state by ignition with carbon ; thirdly, the separation of the earthy impurities of the ore by fusion with other matters into a slag; and, fourthly, the carboniz- ing and melting of the reduced iron. The purest kind of iron ores do not require to be previously calcined, but with most of them it is essential. Some of the larger examples of blast-furnaces have a width at the boshes of 25 feet, and are over 100 feet in height. These are commonly called smelting-furnaces, be- cause the process of separating the iron from its ore, called reducing, is conducted in them. The top or mouth of the furnace serves for charging as well as for the escape of smoke, etc., and is therefore both door and chimney. The tuyeres at the bottom, like the ordinary cupola, serve to supply the air, which is forced in by means of immense blowing-engines. To economize fuel, the blast is sometimes heated to over 1000 degrees before it is delivered into the furnace. The furnace is sometimes charged with alternate layers of fuel (coal or coke and sometimes charcoal), ore, and limestone. When the heat has become sufficiently intense the carbon of the fuel deoxidizes the iron, and carbonic acid is also expelled from the lime, leaving it caustic. Sand and clay, in greater or less quantities, now remain combined with the iron; the lime, acting as a flux, unites with these and forms a slag. The iron as it melts falls to the bottom of the furnace, from whence it is allowed to flow at intervals through a tapping-hole, which when not in use is kept stopped with sand. The slag flows out over a dam, arranged Cast-iron Pipes. 88 Cast-iron Pipes. in such a manner as to retain the molten iron, but to per- mit the escape of the slag, which floats on the iron as fast as it accumulates in sufficient quantity. As fresh supplies of fuel, ore, and flux are charged at the top, the melted iron is tapped at the bottom; where channels from the tap- hole lead the metal into sows, and from thence into the pigs; the process goes on without stoppage, sometimes for years. The product of the smel ting-furnace is, as has been pre- viously stated, "cast iron," containing from 2 to 6 per cent of carbon, which in the white irons is chemically combined with the iron; while in the gray it is principally graphitic, mechanically distributed through the iron. There are also other impurities contained in cast iron, including silicon, sulphur, and phosphorus, and sometimes manganese. Cast iron is easily distinguished from malleable by its granular texture and brittleness, which precludes all possibility of forging; but it is this very quality that gives it its value as a foundry iron, because it can be so readily remelted and cast into moulds. It is presumed that cast iron expands at the moment of assuming the solid from the liquid state ; this expansion being caused by the particles assuming a crystalline arrange- ment as the mass solidifies, but that a subsequent contrac- tion takes place gradually as it becomes cold. See Water- tuyere ; Calcination" ; Ores ; Sow ; Pig Iron. Cast-iron pipes are tubes of cast iron for con- veying water or other fluids. Elbows, bends, curve, branch, tee, flange, hawse, as well 'as odd shapes of water and other pipes, etc., all come under the general name of jobbing pipes, and are made in almost every foundry. But the straight-length socket pipe, of which so many thousand tons, of every dimension almost, are made each year for the water- works systems, are now all made by firms devoted exclusively to the manufacture of that class of Cast-iron Pipes. 83 Cast-iron Pipes. castings. The defects formerly existing by reason of the employment of unskilled labor at nearly all the pipe foun- dries have long since ceased to exist, as the work now emanating from these concerns incontestably proves. As made by the regular establishments, pipes are all cast vertically in cast-iron casings, having the core on a barrel. The flasks are rammed vertically on fixed founda- tions, with guide to receive the mandrel or pattern. The cores are accurately struck on barrels, in the customary way, the barrels being provided with ample means for handling and self-adjustment; which leaves little to be done except to elevate the dried core, and lower it into the prepared seat at the bottom of the mould. Moulds and cores are thoroughly dried before casting. The following table gives the weight of one foot in length of pipes from 1 inch to 22 inches diameter : Diam. Thick- ness. Weight. Diam. Thick- ness. Weight. Diam. Thick- ness. Weight. Ins. Ins. Lbs. Ins. Ins. Lbs. Ins. Ins. Lbs. 1 | 3.06 H i 18.4 5 5 ■g" 34.34 ■g- 5.05 5 s 23.72 I 42.28 n i 3.67 1 29.64 ** l 2 29.4 3 ■8 6. H i 19.66 5 S" 37.44 n ff 6.89 f 25.27 t 45.94 1 9.8 3 31.2 6 1 31.82 if 3 "g" 7.8 8f 1 ¥ 20.9 1 40.56 1 11.04 f 26.83 3 49.6 2 8" 8.74 f 33.07 | 58.96 1 •2 12.23 4 1 22.05 H 1 2 34.32 2J 3 •g" 9.65 f 28.28 5 43.68 * 13.48 f 34.94 f 53.3 *k 3 10.57 4i 1 23.35 7 f 63.18 1 2 14.66 5 29.85 7 36.66 f 19.05 3 36.73 5 8 46.8 2f | 11.54 ±i ■g- 24.49 3 56.96 1 •J 15.91 5 8 31.4 7 g" 67.6 5 ■g" 20.59 3 38.58 1 78.39 3 3 12.28 4f 1 25.7 ' 2 h 39.22 1 17.15 f 32.91 f 49.92 5 "g" 22.15 ■j 40.43 3 60.48 t 27.56 5 1 26.94 7 8 71.76 Cast-iron Pipes. 90 Cast-iron Pipes. Diam. Thick- ness. Weight. Diam. Thick- ness. Weight. Diam. Thick- ness. Weight. Ins. Ins. Lbs. Ins. Ins. Lbs. Ins. Ins. Lbs. u 1 83.28 1 122.62 1 161.83 8 i 41.64 12 h 61.26 16 1 80.87 5 8" 52.68 5 8 77.36 5 8 101.82 3 4~ 64.27 4~ 93.7 1 123.14 f 76.12 7 ■g- 110.48 | 144.76 1 88.2 1 127.42 1 166.6 8i 1 "2~ 44.11 12* i 63.7 16i 1 2 83.3 5 56.16 5 80.4 5 S 104.82 i 68 4- 97.4 S 126.79 f 80.5 f 114.72 I 149.02 1 93.28 1 132.35 1 171.6 9 i 46.5 13 1 2" 66.14 17 i 85.73 5 -g 59.92 5 8" 83.46 5 8 107.96 3 71.7 f 101.08 3 4 130.48 1 84.7 7 8 118.97 7 8" 153.3 1 97.98 1 137. 2S 1 176.58 H 1 "2 48.98 13i 1 68.64 171 1 "2 88.23 5 62.02 f 86 55 5 8 111.06 3 4- 75.32 f 104.76 4" 134.16 | 88.98 7 8 123.3 7 "8 157.50 1 102.09 1 142.16 1 181.33 10 1 ■3 51.46 14 1 •2 71.07 18 1 114.1 5 65.08 5 ■g- 89.61 f 137.84 I 78 99 f 108.46 | 7 8 161.9 93.24 7 ft 127.6 1 186.24 l 8 108.84 1 147.03 ! 19 5 "8 120.24 10i 1 •3 53.88 14* 1 73.72 1 145.2 5 68.14 5 92.66 ; f 170.47 3 82.68 f 112.1 1 1 195 92 7 •5" 97.44 7 8 131.8 20 5 ■8 126.33 1 112.68 1 151.92 J 152.53 11 1 56.34 15 1 75.96 179 02 5 71.19 5 95.72 1 205.8 f 86.4 f 115.78 21 5 8 132.5 | 101.83 | 136.15 3 4" 159.84 1 117.6 1 156.82 7 "g" 187.6 iH i 58.82 15i i 78.4 1 215.52 5 8 3 "J 74.28 1 98.78 22 5 "8 138.6 90.06 3 1 119.49 4" 167.24 1 106.14 7 140.4 1 196.46 To find the weight of a pipe, let the following rule be observed: To the inner diameter add the thickness of metal; multiply by 3.1416 for the circumference, and the Cast Iron, To Braze. 91 Cement. product by the thickness. This gives the number of inches contained in the end section of the casting, which, when multiplied by the length, gives the total cubic inches, which, if multiplied by the weight of a cubic inch of the metal used, will give the total weight. See Columns. Cast Iron, To Braze. — Clean the parts to be joined and tin them well. They may be now placed together in the sand, or elsewhere, and melted brass poured over them. See Soldering. Cast Iron, To Chill. — Use soft-water, 10 gallons; salt, 1 peck ; oil of vitriol, i pint. Heat to a cherry red and dip, continuing to dip until hard enough. See Case- hardening. Cast Iron, To Soften. — Water 4, aqua-fortis (nitric acid) 1; steep for 24 hours. Cast Iron Mixtures.— See Mixing Cast Iron. Cast Steel. — See Crucible Steel. Catalan Forge. — A simple kind of open-hearth fur- nace, once common in Catalonia, Spain, for producing malleable iron ; some few are found there still, as well as in some other parts of Europe and America. In their crudest form they consist of a simple hole in the ground, in which are contained the ignited charcoal and the substances to be heated ; the fire being urged by a blast of air blown in through one or more nozzles or tuyeres, from either a rude bellows or a tromp. See Tromp. Cement. — These substances are generally employed in a semi-fluid or pasty state to unite bodies in close adhe- Cement. 92 Cement. sion, the latter condition being the most favorable for bringing the opposing surfaces into intimate contact. Marine Glue. — Glue 12, water enough to dissolve; add yellow resin 3 ; melt, and add turpentine 4, and mix thor- oughly together. Cement for Lamps. — Rosin 3, caustic soda 1, water 5, boil; then add half its weight of plaster of Paris. Sets in f of an hour; not permeable to petroleum. Cement to Resist a Red Fire, Water, and Oils. — Equal parts of sifted peroxide of manganese and zinc white; soluble glass, sufficient to form a thin paste. See Solu- ble Glass. Another : Pulverized litharge 5 lbs., fine Paris white 2 lbs., yellow ochre 4 oz., hemp cut in shreds i oz.; this is ready for use when it has been mixed to the consistency of putty with boiled linseed-oil. Liquid Glue. — Glue, water, and vinegar, each 2 parts. Dissolve in water-bath, and add alcohol 1 part. Cement for Steam-boilers, Steam-pipes, etc. — Red or white lead, in oil, 4 parts; iron borings, 2 or 3 parts (soft), or iron borings and salt water, and a small quantity of sal- ammoniac with fresh water (hard cement). For Holes in Castings. — Sulphur in powder, 1 part; sal- ammoniac, 2 parts ; powdered iron turnings, 80 parts. Make into a thick paste. The ingredients comprising this cement should be kept separate and not mixed until re- quired for use. Cement for Stopping Holes in Cast Iron. — Iron filings, 15 parts; sal-ammoniac, 2 parts; sulphur, 1 part; ground or powdered stone, 2 parts; add water until it is about the consistency of common paste; it is then ready for use. For Making Canvas Water-proof and Pliable. — Yellow soap, 1 pound, boiled in 6 pints of water; add, while hot, 112 pounds paint. Cement for Rust-joi?its (Quick-setting). — 1 pound sal- Cementation. 93 Chain. ammoniac in powder, 2 pounds flour of sulphur, 80 pounds iron borings (made to a paste with water). Stone and Iron. — When stone and iron are to be cemented together, use a compound of equal parts of pitch and sulphur. For Cisterns and Water-casks. — Melted glue, 8 parts; linseed oil, 4 parts; boiled into a varnish with litharge. This cement hardens in about 48 hours and makes tight joints. Rice Glue, or Japanese Cement. — Eice flour; water, suffi- cient quantity. Mix together; then boil, stirring it all the time. Cementation is a chemical process consisting of surrounding a body in the solid state with the powder of some other body or bodies, and exposing the whole for a time to a degree of* heat insufficient to melt the contents. By this means iron is converted into steel when packed in powdered charcoal, and green bottle-glass into porcelain by sand, etc. See Blister-steel. Centre. See Spindle; Loam-moulding. Chain. — A chain consists of a series of iron links welded one within the other. The very critical and par- ticular uses made of chains in a foundry and elsewhere should suggest the propriety of devoting more attention to their careful preservation. The fewer their number the greater probability of a right selection and legitimate use. The tensile strength of good chain iron is about 41,000 lbs., but in order to maintain that high state of efficiency chains must not be subjected to the barbarous sys- tem of hammering one sees sometimes in order to release a few kinks. Another vile method is to take heavy lifts when one or more of the chains have been purposely Chain-slings. 94 Change-hook. shortened by twisting. A few fractured chains, and may- hap a life lost, would be of infinitely greater cost than a handy set of swivel-chains, by which means an even lift can be obtained as precisely as may be desired. Instead of be- ing thrown down on the damp floor, chains should always be hung up and carefully protected from rust. An occa- sional heating to a dull red in a charcoal fire, followed by a long protracted cooling while shielded from the atmos- phere, is of great service, and tends to restore the quality of ductility. Hard knocks, overstraining, lifting with twists, moisture, sudden changes of temperature are all favorable to crystallization, and hence fatal to the well- being of chains (see Swivel-chain). For strength of chains and ropes, see Ropes. Chain-slings.— See Slings. Chalk is nearly a pure carbonate of lime; it effervesces with acids and burns to quicklime. In England it forms in beds sometimes more than 100 feet high. The solid stone is used for building with. It is an excellent lime for cement and a good polishing substance. See Lime- stone. Chalk Composition. — For obtaining impressions of simple objects, as medals, etc., or for forcing into well-oiled moulds, as busts, statuettes, etc., this composition is very good. It is composed of powdered chalk and thin glue worked to the consistency of putty, which, when allowed to dry, becomes almost as hard as marble. All that is needed is to press the composition hard down into all the cavities of the mould, and the impression is perfect. See Plastek- cast. Chanare-hook. See Double Hook. Cliaplet. 95 Charcoal-facing. Chiiplet. — A chaplet proper consists of a stem of in- definite length, terminating at one end with an increased flat surface, which renders it less likely to be thrust into the core by pressure or weight. If this plate end is forged out of the whole piece the chaplet is a good one, and may be relied upon ; but a riveted end is an abomination for more reasons than one. In the first place they are apt to slip through unless the shoulder is enlarged, and that is not sufficient to prevent the head from flying off when struck; consequently, whether they are home-made or purchased from the dealers, the solid ones are to be preferred. By means of a match-plate very many excellent chaplets for ordinary pur- poses may be made of cast iron ; for many jobs they are infinitely superior to wrought iron, and very much cheaper. Chaplet is the general term for almost every device for holding down or supporting cores and sections of moulds ; even springers are recognized as a species of chaplet, and so called in many parts (see Spring-chaplet), and solid studs of almost every description go by this name. Two important features in this connection are rust and lack of material. Both of these conditions are fatal to a mould — the former because of the large amount of gas evolved when the rust decomposes; the latter because of their too frequent use in parts where the current of metal dissolves the stud, leaving the part without support. Both studs and chaplets are incorrectly called anchors in some foundries. See Anchor. Charcoal.— Charcoal is what remains of wood after it has been exposed to a strong heat while protected from the access of the atmospheric air. Charred bituminous coal produces what is termed coke. See Coke. Charcoal-facing.— The dust of pulverized charcoal, See Facing, Charge. 96 Charging-doors. Charge. — The amount of metal, fuel, flux, etc., intro- duced into the furnace at one time, either as one of a number of charges to constitute a whole heat, as in a cupola, or, as the whole quantity charged at once, as in a reverberatory furnace. Too much intelligence cannot be brought to bear on the operation of charging the cupola, as not only may there be a substantial saving effected in the quantity of fuel used, but time in melting may be shortened, as well as hotter iron produced when the true proportions of fuel to iron has been once accurately determined. Commence with 9 pounds of iron to 1 of fuel above the bed-charge, and con- tinue this for one day, noting well the length of time taken to melt the heat, as well as the temperature of the iron melted ; then gradually decrease or increase the amount of fuel, as occasion demands, until the smallest percentage pos- sible is reached, after which the whole labor of charging is re- duced to a positive science, demanding only accurate weigh- ing of the materials used every day to insure satisfactory results at every heat, providing the requisite blast-pressure is maintained on every occasion. See Cupola; Eatio of Fuel to Iron; Charging the Common Cupola. Charging-doors are the doors used for closing the mouth of the cupola after the charge has been thrown therein. It is a great mistake to provide a too limited hole through which to charge the iron and fuel; when this occurs, the operations are sure to be faulty, as the cupola- man cannot place the alternate layers of fuel and iron with the regularity necessary for even melting. Very much of the irregularity in melting, so prevalent almost everywhere, could be prevented if a capacious aperture was provided with close-fitting doors, which latter should be kept closed after the charge is in. See Cupola; Charging the Com- mon Cupola, Charging-hole. 97 Charging Cupola. Charging - hole. — The mouth of a cupola. See Charging-doors. Charging-platform (scaffold). — The stage upon which fuel and iron is stored for convenience in charging. Usually the platform is built about 3 feet below the charging- hole and immediately in front of the latter. Position and capacity are two important features. The former should be chosen with reference to possible future developments, — such as additional cupolas, improved facilities for raising material, etc., — while the latter in all cases should be of strength sufficient to bear with perfect safety all the mate- rials for one day's heat, and ample in area to do this with- out in any sense interfering with the charging operations. See Cupola; Charging the Common Cupola. Charging the Common Cupola. — The follow- ing table of common straight cupolas, from 24 to 84 inches diameter inside of lining, all of which have a bed depth of 10 inches, show what amount of fuel is required for the bed, first charge of iron, and succeeding charges of fuel and iron. Also blast-pressure and tuyere area required to melt a given quantity of iron per hour, as well as the total melting capacity of each cupola designated. All the fig- ures are based upon what may be considered as safe prac- tice under ordinary conditions. A proportionate increase or decrease of bed fuel is necessary when the depth of sand-bed differs either way from 10 inches, as given; and any increase of burden in order to obtain improved ratios of melting must be introduced gradually. The results as per table are absolutely certain when the power is adequate and blast-pipes, etc., sufficiently capacious and free from leaks. The total melting capacities given represents what may be expected irrespective of any system of slagging, or other means ordinarily adopted for continuous melting: Cheek. 98 Chill. la In. 24 30 36 42 48 54 60 66 72 78 84 2£ ■d a ■T3 > pq a OB CO „ h © .C 3 o P a> Pi -£H o ft 8? t-^ >% St=! «W OS cS K^^ 3 +; Cfi o % o A A © o CO direct contact with the casting. In a plain mould, con-- Gate-pin. 182 Gathering Metal. sisting of a cope and nowel, containing two or more cast- ings which must be filled at one operation and without a runner-basin, the metal would enter from the ladle by the sprue into and down the clown-gate into the main runner, and from thence into the castings through ingates or sprays connecting with the main runner. See Basin; Down-gate; Kunner; Skim-gate. Gate - pin. — An upright runner (round, square, or flat) which is rammed up vertically in the cope, and forms the connection betwixt the orifice for pouring into, and the system of gates below. The gate-pin is not unfrequently termed a runner-stick. See Down-gate; Gate. Gate-rake. — A strong, four-pronged steel fork for lifting the gates and medium heavy scrap out of the sand in the scrap-pile. The prongs are wide apart to allow all isand to fall through, and for this reason are preferable to an ordinary shovel for such use. Gate-spool. — An inverted cone, usually made of wood, and turned smooth, with a handle projecting from its base. It is used for pressing back the sand and making smooth the upper edges of a sprue-runner, forming a fun- nel-shaped and cleanly formed entrance for the metal. A runner manipulated thus is called a sprue. See Gate. Gathering Metal is a term used to indicate the collecting of a large quantity of metal for the purpose of pouring a heavy casting. If three or four ladles are used for casting a piece 20 tons, the metal is said to be gathered in that number of vessels. If a dam is constructed in which to run from cupolas, pour from ladles, or both means combined, all the metal required : it is then gathered in the dam. It is common in some places to supplement the regular melting in the air or reverberatory furnace by si- Gauge. 183 Geared Ladie. multaneous melting in the cupola, transferring the metal from the cupola to the bed of the air-furnace as fast as it melts. This is accomplished by means of an inclined runner or spout placed so that the metal will enter the air- furnace at the side and directly over the reservoir. In the latter instance the metal is gathered into the air-furnace, which, if suitably constructed, is assuredly the very best arrangement for collecting metal in large quantities, as by this means the metal is maintained at a suitable tempera- ture and is thoroughly mixed — something which cannot be satisfactorily done by either of the above described methods. See Dam. Gauge, or Gage, is an instrument for measuring with. It may be adjustable, like the caliper, or a fixed and standard measure, as a gauge-stick for loam-work, and may be employed for testing inside or outside surfaces. Also, an instrument for measuring any special force or dimension, as a pressure or blast gauge for cupolas and blast-furnaces. See Caliper ; Blast-gauge ; Pressure- gauge; GrAUGE-STICK. Gauge-stick. — A fixed measure employed by a loam- moulder. One edge is straight; its full length represents outside diameter, and notches indicate the core's diameter. A semicircle, cut midway along the straight edge to fit the spindle, enables the moulder to set his sweep-boards, and test the accuracy of his work entirely independent of his rule. It is made handier by reducing its bulk from the middle to the extremities on the back edge. See Gauge. Geared Ladle. — A pouring ladle provided with mechanism for tipping, invented by James Nasmyth, England. Makers of geared ladles, now very numerous, mount them with every conceivable variety of suitable gearing, from the simple wheel and pinion, spur or worm, Gems, Imitation. 184 German-silver. to the more elaborate ones that are double-geared, or with mitre-wheels in addition to the worm-gearing. See Ladle. Gems, Imitation.— See Paste Gems. German-silver. — An alloy deriving its name from the circumstance of its being first made at Hildesheim, Germany. It is a useful silver-like alloy, composed gen- erally of copper, nickel, and zinc. It resembles the Tutenag of the Chinese, and is used principally for table articles, and in electro-plating. Copper 3, zinc 1, and nickel 1 is perhaps the most silver-like alloy. Tiers- argent, an alloy of German with real silver, has come into use of late. It consists of copper 59.0, nickel 3.4, zinc 9.6, silver 27.6. This alloy is prepared either by fusing the copper and nickel together in a crucible and introducing heated zinc piece by piece, or by finely dividing the metals, and melt- ing in an air-furnace under a good layer of charcoal. These mixtures should be well stirred to promote a thorough solution of the nickel. The crystalline structure of German-silver is destroyed by heating to a dull red and allowing to cool slowly; this renders it more suitable for working. The alloy is harder than silver, resembles the latter in color, tarnishes yellow in the air, and melts at a bright heat, losing its zinc by oxidation if exposed to the atmosphere. German-silver is exceedingly brittle at a heat just above a dull red. The ordinary composition for knives and forks is copper 4, nickel 2, zinc 2. That for handles for spoons and forks is copper 5, nickel 2, zinc 2. Metal for rolling is composed generally of copper 3, nickel 1, zinc 1. Candlesticks, bells, spurs, and similar articles that are cast are simply the .German silver alloyed with from 2 to 3 per cent of lead. German Tutania. 185 Gilding. When iron is added to the German-silver composition, it is best to use tin-plate iron, which must be first melted along with part of the copper. If from 2 to 2-| per cent of iron be added to German-silver, after the manner as above described, the metal will be much whiter, but harder also, and more brittle. Park's German-silver contains : copper 91.0, nickel 45.5, zinc 21.0, iron 45.6. An English patent has: copper 5, nickel 4, zinc, tin, lead, and antimony 1 of each. A very malleable German-silver is made from : copper 5, nickel and zinc 7 each. Very many silver imitations are described in their proper order throughout this work. See Pack- fong ; Parisian White Metal ; German Tutania ; Tombac ; Britannia Metal; White Alloys. German Tutania. — A beautiful white alloy for table-ware, etc. Its composition is: copper 1, antimony 4, tin 48. See German-silver; White Alloys. German White Copper.— Copper 88, nickel 8.75. See White Alloys. Gig. — A light, portable centre for sweeping small moulds and cores, etc., in either loam, sand, composition, or plaster. See Spindle, Gilding,— The three methods of gilding are: mechani- cal, chemical, and encaustic. Picture-frames, etc., are first oiled and then coated with whiting and glue, after which the gold size is applied to such parts as do not require bur- nishing ; those which do are simply sized with the clear animal size. The gold-leaf is then applied with a brush. Electro-gilding is generally practised for metals. Water- gilding is simply applying a gold amalgam paste to the metal, and afterwards applying heat, which volatilizes the Globe. 186 Glue. mercury, leaving the gold. The amalgam is made by plac- ing grain or leaf gold 1 in a clean iron ladle, add mercury 8, and apply a gentle heat until the gold is dissolved, stir well with a clean iron rod, and run it on a clean slab. 'This, when cold, is the amalgam, ready for use. The cleaned metal to be gilded is first rubbed over with :.a solution of nitrate of mercury, and at once covered with ;a thin coat of the amalgam. Heat is then applied to vola- tilize the mercury, and the gold adheres. Cheaper gilding may be made by increasing the quantity of mercury in the amalgam. Steel may be gilded by dipping the polished article into the ethereal solution of gold ; on withdrawing, the ether evaporates, leaving the gold. A cloth dipped in the solu- tion and wiped over the article answers the purpose. See Stains foe Metals; Tinning; Zinc Coating. Globe.— A sphere, a ball. See Sphere ; Ball. Glucinum. — A metal resembling aluminum, pre- pared after the same manner. It is a rare metal, and was discovered by Wohler, 1828. See Aluminum. Glue is an impure gelatine, made chiefly from frag- ments of hides, hoofs, bones, etc. Besides the many uses to which it is put for carpentry, pattern-making, etc., it is capable of furnishing an excellent means for imparting cohesiveness to the several free sands used for cores. When used as a glue water for dampening the sand, the gelatine binds the particles of sand together with a jelly-like sub- stance, which, when the water has evaporated during the drying, leaves the core hard and brittle in proportion to the quantity of glue in the water. By using the smallest quantity necessary to stiffen pure sand, little or no gas is generated by the heat, thus making it possible, in numer- Glue Moulds 187 Gold. ous instances where it is difficult to obtain a vent, to use cores that are devoid of vents altogether. When cores of this class have been burnt by the metal there is no diffi- culty in extracting them from the castings, the glue hav- ing burned away, leaving only the incoherent sand. See Free Sand; Core-sand; Flour. Glue Moulds. — Plaster casts of intricate objects may be obtained by making the mould of glue. Bunches of grapes, etc., for instance, are taken in their natural shape by covering them all over with glue, then cutting through the middle and extracting the grapes, after which the halves are joined together accurately and the cavity filled with plaster. A perfect cast of whatever object has been treated will be discovered after the glue has been melted off with boiling water. See Elastic Moulds. Gluten is vegetable fibrin. If wheat flour is made into a dough and kneaded on a sieve under a stream of water, the starch is carried away, leaving a gray, tough, and elastic substance having the appearance of animal skin, and which when dried has a glue-like aspect ; hence the name. See Starch. Glycerine is a colorless, inodorous fluid, of a sweet taste. The usual method of obtaining it on a small scale is from olive-oil. See Oils. Gold is a metal very widely diffused, occurring princi- pally in grains, but sometimes in larger pieces weighing some pounds; it also occurs in the crystalline form in some- instances. Its color is yellow, lustre brilliant; specific grav- ity 19.258. It is the most malleable of metals, is ductile: to a high degree, and as soft as lead when pure. It melts, at 2587° F., and is not affected by air or water at any- temperature. Gold. 188 Gold, The usual solvent for gold is aqua regia, a mixture of nitric acid 1, chlorhydric acid 3 to 4. The name of this solvent means royal water, so called from its power of dis- solving the king of metals. Gold, like silver, in a pure state is seldom used in the arts, except perhaps as a solder for vessels of platinum for laboratory uses. Dentist's and gilding gold usually con- tains about 6 grains of copper to one ounce of gold. Stand- ard gold, copper 1, gold 11, has a density of 17.157, and is harder and more fusible than gold when pure. The French standard is copper 1, gold 9. Carat is a term used to designate one of the parts or units of a certain number which is taken as the standard of pure gold. In the United States the number is 24 ; hence pure gold is said to be 24 carats fine. If it contain 2 parts alloy, it is then 22 carats, etc. Gold is separated from all its ores, except silver, by amalgamation with mercury. (See Amalgamation.) It is obtained from silver by boiling it with nitric acid, which dissolves out the silver, leaving the pure gold. See Sepa- kating Metals. Most metals combine with gold, increasing its hardness but impairing its ductility. With silver 29.2, gold 70.8, the jeweller's composition called green gold is produced. The maximum degree of hardness with silver is obtained when the silver constitutes one third of the alloy; with copper it is one eighteenth. Twenty per cent of iron with gold produces the jeweller's gray gold, and 75 per cent makes an alloy of silvery white- ness, hard enough for cutting instruments. Thirteen hundred miles of silver wire may be covered by one ounce of gold, the leaf is reduced to the 290,000th part of an inch, and a leaf of 56 square inches may be beaten out of one grain of this metal. See Gilding; Alloy; Tombac ; Gold Alloy. Gold Alloy. 189 Grades of Pig-iron. Gold Alloy.— An imitation resembling the pure metal in color and of about the same specific gravity is made by melting together in a crucible, well covered with charcoal- dust, copper 7, platinum 16, zinc 1. Mannheim gold, an- other beautiful imitation, is made in the same way from copper 16, zinc 4, tin 1. Gold 75, copper 25, and a little silver is a remarkable jewelry composition. Gold -leaf. —See Gold. Gold-solder.— Take gold of the same quality as the article to be soldered, and add T ^ of silver and -fc of copper. A larger proportion of silver and copper may be added for articles not so fine. See Solders. Gong-metal is composed of copper 78 to 80, tin 20 to 22. After casting, the metal is subjected to a process of hammering and annealing. Owing to the brittleness of the mixture, great care and judgment is required to beat it into the flat basin-shaped gong, which, when struck with the mallet, puts the metal into such an extraordinary state of vibration as to produce the piercing sound emitted. Annealing is obtained by heating to a dull red, and sud- denly immersing in water. When cold, the hammering can be continued until a point of brittleness is reached, when a repetition of the annealing process is made necessary, and so on until completed. See Alloys; Brass. Grades of Pig-iron.— Pig-iron produced from the same ores differs in its nature and quality, and must be rated or graded in such a manner as will indicate the special purpose for which each is applicable. Broadly stated, the classifications are commonly understood as gray, mottled, and white — a condition discovered by the fracture; but the gray iron is subjected to still further divisions, termed No. Grain-tin. 190 Graphite. 1, No. 2, No. 3, etc., according as the fracture indicates the various degrees of hardness, commencing at the softest, No. 1, the numbers advancing as the hardness increases up to the point where they cease to be suitable for general foun- dry purposes, and are classed as forge-irons, being fit only ior conversion into malleable iron in the puddling-furnace. 'The lack of fluidity common to the latter grades is a qual- ity which makes them highly desirable for the puddling process, as in melting they pass, just before fusion is com- plete, into a pasty mass favorable for decarburization much •easier and with less loss than could be possible if the pig- iron were gray and more fluid. See Malleable Iron. Grain-tin.— See Tin. Granite is a widely known igneous rock, composed of quartz, feldspar, and mica, united in a confused crystalliza- tion. Feldspar predominates, and quartz is greater than mica. It is so called because of its granular structure. The decomposition of the feldspar of some kinds of granites produces the kaolin used for porcelain, and for many purposes in metallurgy. When granite decomposes and becomes mixed with organic matter it makes good soil. See Kaolin; Mica; Feldspar; Kock; Earths. Granulated Zinc— See Zinc, To Pcjrlfy. Grapes, A Plaster Cast of.— See Glue Moulds. Graphite. — The nature of graphite, sometimes called plumbago or black lead, is not generally understood. Emi- nent writers on friction have declared that graphite is the best natural lubricant known, and scientific and mechanical papers have advocated its use for many purposes. Incom- petent, if not unscrupulous, parties have attempted to meet Graphite in Pig-iron. 191 Graphite in Pig-iron, the demand by putting on the market graphite productions that are totally unfit for the uses specified. Graphite is one of the forms of carbon. It is not affected by heat or cold, or any known chemical. As it comes from the mine, however, it contains from 50 to 80 per cent of silica, sulphur, and other impurities, and the process of completely freeing the graphite from impurities requires very expensive machinery and the most skilful manipula- tion. Only manufacturers having such facilities can hope to produce an absolutely pure article. The impurities in much of the graphite now in the market take on the ap- pearance of graphite by contact, and such impurities are sometimes undetected even by the expert, unless chemical tests are employed. This is especially true of amorphous graphite, commonly called black lead, which is graphite without any particular form, and usually mixed with clay. Pure graphite, and even black lead, is useful in many ways ; but to be useful in the highest degree the graphite should be carefully selected with a view to the use intended. Graphite suitable for lead-pencils is not the most suitable for lubricating, although it has lubricating qualities. Again, graphite suitable for stove-polish would not answer for crucibles, although it might be equally pure and stand the heat equally well. Graphite varies greatly in its construction and usefulness,, and the best results are only brought about through experi- ence, knowledge, and proper mechanical facilities. See Black Lead; Facing. Graphite in Pig-iron.— Pig-iron contains from 2 to 6 per cent of carbon, some portion of which is held in chemical combination with the iron, the rest being distrib- uted throughout the mass mechanically. The latter is called graphitic carbon, or graphite. This graphite is seen as scales, which may be detached from the mass when the Gravity. 192 Green-sand Core. pig-iron is reduced to powder, and may also be found among gray-iron borings that are subjected to a process of grinding and sifting. If gray iron that has been melted in contact with an excess of carbon is allowed to cool slowly, the carbon crystallizes out and forms graphite ; this is commonly called Kish in the foundry, and it is always seen to gather when the iron is melted under conditions answering to those described above. See Kish ; Carbon. Gravity.— See Specific Gravity. Gray Pig-iron is all pig-iron that contains a large proportion of its carbon in a graphitic state. Such irons may be distinguished by their crystalline fracture and dark- gray color. See Cast Iron. Green-sand is moulding-sand in a moist condition, and suitably mixed to form moulds in which the metal can be poured at once, without subsequent drying. See Facing- sand ; Dry-sand Moulding ; Green-sand Moulding ; Dampness. Green-sand Core. — The inner mould, whose out- side surface has been fashioned to correspond with the desired form of the inside of a casting, and which has been constructed exclusively from materials favorable to a suc- cessful issue without the intermediate process of drying consequent upon cores that are made from dry-sand ma- terial. The chief requirements in this mode of core-mak- ing are, first, a suitable core-bar, or arbor (see Arbor), to carry the sand ; second, a tough, strong sand for the lower hanging surface, the upper surface and the interior of the core being formed with sand as open as may be consistent with safety ; and thirdly, an uninterrupted passage for the vents if they are open ones ; but in large cores cinders are Green-sand Moulding. 193 Greiner Patent Cupola, always preferable. See Facing -sand; Greek -sand MOULDING:. Green-sand Moulding is the art of constructing moulds capable of resisting the destructive influence of molten metal without the subsequent drying incident to loam and dry-sand moulding. More skill is required to mould similar castings in green-sand than by either of the other methods, because the moulds cannot possibly be made as rigid and unyielding ; therefore there must be superior ingenuity displayed to overcome these disadvantages. Every process connected with green-sand work must be worked with greatest care, provision for sustaining and anchoring cores and portions of mould must be made inde- pendent of the mould proper, and in all cases the efforts of the moulder are directed to a maintenance of all the parts of his mould in their exact position without actual contact, otherwise the incoherent material out of which he must necessarily form the mould will be shattered and the mould destroyed. This is by no means the case in loam and dry- sand moulding: the dried loam or sand is compact and hard, and in most cases capable of sustaining its several parts without fear of damage, in addition to which the dried moulds offer a surface always freed from moisture and gas-creating substances, the eradication of which in green-sand moulds must necessarily take place during the process of filling the mould with metal. See Dry-sand Moulding ; Loam-moulding. Greiner Patent Cupola.— This remarkable cupola is thus described by the patentee : " The novelty of the invention consists in a judicious ad- mission of blast into the upper zones of a cupola, whereby the combustible gases are consumed within the cupola and the heat utilized to preheat the descending charges, thereby Greiner Patent Cupola. 194 Greiner Patent Cupola. effecting a saving in the fuel necessary to melt the iron when it reaches the melting zone. In order to fully ex- plain the principle of its workings, we will suppose a cupola of the ordinary design, with a single row of tuyeres or air inlets. The incoming air burns the coke in front of the tuyeres to carbonic-acid gas, a combination indicating per- fect combustion. As this gas ascends through the incan- descent coke above, most of it is converted into carbonic oxide by the absorption of an equivalent of carbon. The result of the combustion is, therefore, a gas mostly com- posed of carbonic oxide (CO), indicating an imperfect utili- zation of the fuel, as one pound of carbon burned to car- bonic acid (C0 2 ) will develop 14,500 heat-units ; whereas the same amount of carbon burned to carbonic oxide (CO) will only develop 4480 heat-units, or less than one third of the heat developed by perfect combustion. " To avoid this loss of heat additional tuyeres have been placed at a short distance above the lower tuyeres to intro- duce air to consume the carbonic oxide (CO), but such arrangement does not have the desired effect, because the material at that place in the cupola has a very high tem- perature, consequently the entering air also ignites the coke, so that the action at the lower tuyeres is simply re- peated, and carbonic oxide (CO) again formed at a short distance above." This led Mr. Greiner to the following conclusions : " In every cupola there must be a point above which the descending materials have not yet reached the temperature necessary for the ignition of the solid fuel, while the as- cending combustible gas is still warm enough to ignite when brought into contact with air. It is clear that air, if properly admitted above that point, will cause the combus- tion of the carbonic oxide (CO) without igniting the coke. " But if all the air necessary for the combustion of the carbonic oxide (CO) be admitted at one place or in one Grids. 195 Grouting. horizontal row of tuyeres, the heat developed will very soon raise the temperature so as to set fire to the coke, producing loss of carbon as before. Hence the upper blast must not be introduced on a horizontal plane, but through a number of small tuyeres, arranged (either in the form of a spiral or otherwise) so as to embrace the higher zones of the cupola, and must be regulated, both as to pressure and arrange- ment and dimensions of pipes, according to the capacity of each particular cupola. " The combustible gases are thus burned without heating the coke to incandescence, and the heat thus developed utilized to preheat the iron and the coke, .so that they reach the melting zone at a higher temperature and require less heat to effect the melting." See Cupola ; Combustion". Grids is the name sometimes given to core-irons made similar to a grate of cast iron and used for sustaining bodies of sand which extend beyond the edge of a lifting-plate, etc., in green-sand work; also with and without prickers for dry- sand cores. In the former instance they may be made to serve a good purpose. By bolting or clamping the back edge to the lifting-plate the extending mould is as firmly held as if it rested on the plate itself. They also constitute a method of tying green-sand drawbacks, etc., far superior to tie-rods. See Tie-rods; Core-iron; Drawback. Grooved Drums. — See Spiral Drums. Grouting. — The process of pouring a thin mixture of kaolin or fire-clay betwixt the cupola shell and the fire- bricks, as well as at the joints of the bricks, during the operation of lining. By building the bricks in as close contact with the shell as possible and filling the remaining spaces with the grout, the brick is permanently fixed, and all possibility of air escaping through the joints of the shell obviated. See Cupola; Repairing the Cupola. Gudgeon. 196 Gun-metal. Gudgeon. — The cast or wrought iron journal-piece inserted in the ends of a core-barrel, forming a horizontal shaft or axle, with collars for turning in V's or semicircles, provided on the upper edge of the trestles which constitutes a part of the core-lathe. See Core-lathe; Core-barrel. Guides for Green-sand.— See Stakes; Flask; Pin and Cotter. Guides for Loam-work. — These guides are of necessity somewhat temporary, and require to be well preserved during the time the mould remains separated, otherwise it is difficult to close each piece in its place cor- rectly. If the joints are made by the spindle and sweep, let each outside edge be struck at an angle of 45° with the joining surface, extending a plain face f inch in each direction. By this means both edges can be seen and felt, and any discrepancy overcome more easily than when one slides into the other by a shallow taper seating. If iron ring or plates meets loam, then make the loam to cor- respond, and smooth clayey sand over both, dividing at the joint, and marking a few lines thereon with a thin trowel. Should both joining edges bo loam, both notches and lines may be made. See Loam-moulding. Gum-arabic. — See Arabic-gum. Gum-elastic— See India-rubber. Gum Resins.— See Resins. Gun-founding.— See Cannon; Ordnance. Gun-metal. — A soft gun-metal that will bear drift- ing is made from : copper 16, tin 1. Harder, for heavy guns: copper 9, tin 1. A small proportion of zinc aids Gutta-percha. 197 Gypsum. the alloy to mix well, and increases the malleability with- out materially affecting its hardness. Sterling's gun-metal is copper 50, zinc 25, iron 1 to 8. Rosthorn's is copper 56.33, tin 0.49, zinc 41.29, iron 1.84. See Alloy; Brass; Bronze; Tin; Copper. Gutta-percha is very similar in many respects to caoutchouc, being the dried juice of the Isonandra gutta tree. When mixed with about one fourth of linseed-oil it makes a good substance for obtaining moulds from undercut patterns. After obtaining the mixture and kneading it into cakes of suitable thickness, soften the surface before the fire and press firmly on the pattern, and, before it be- comes cold, remove the mould and set it in cold water at once, otherwise it will shrink out of shape. The gutta- percha may be softened by heat until it is possible to press it into the most intricate recesses, but let the final touches leave the mould about equal in thickness all over, taking it off whilst warm, and plunging into water. See Elastic Moulds; India-rubber; Plaster Casts. Gypsum is the sulphate of lime. This salt is found in many parts of the world, forming very extensive rocky beds. When pure and transparent it is known as selenite, and in its other varieties as gypsum, alabaster, and plaster of Paris. Powdered gypsum parts with its water of crystallization when subjected to a temperature of 300°. If it be then made into a liquid paste with water, it again combines with it, and at once commences to harden and resume its stony condition. It is entirely owing to this wonderful property that it can be used for obtaining im- pressions of objects by taking casts whilst in a liquid state. It is mixed with glue and colored for architectural pur- poses, the objects cast being then called stucco-work. See Plaster Casts; Plaster of Paris; Stucco-work. Hammer. 198 Hand-truck. Hammer. — A tool consisting of an iron head fixed crosswise upon a handle. The hammers in common use are of different kinds : including the heaviest sledge, wielded by both hands, with which a very heavy blow may be given; the hand-hammer, which may be used with one hand ; and intermediate sizes and shapes for a variety of uses. The largest hammers are those used in the iron manufactories for forging purposes, being machines moved by steam or some other power, the chief of which will be described under their respective heads. See Steam-ham- mer; Tilt-hammer. Hammer-pick. — A furnace-man's steel tool, having a hammer face and sharpened point at the respective ends of the head. Used for cutting out and trimming the in- side of the cupola. See Pick-hammer ; Repairing the Cupola. Hand-barrow. — A wooden platform provided with lifting-handles at both ends. Such wheelless barrows are extremely useful for carrying light loads, as cores, cast- ings, etc., by two men. Hand-ladle.— See Ladles. Hand-screw Clamp. — A pair of jaws regulated by two hand-screws, used principally by wood-workers, but a very handy contrivance for binding work in the foundry, such as core-boxes, strips of pattern, etc. Hand-truck. — A small vehicle to be propelled by one man. It may be a platform with three or four wheels, Handwriting Impressions. 109 Hardening Metais. with swivel lock on the front for turning easily ; or the common warehouse truck, consisting of two long handles held together with cross-ties, terminating with axle and wheels and a purchase-plate. Handwriting Impressions on Cast Iron.— This is accomplished by the use of a carbon ink, which leaves a substantial and hard body— one that will not be destroyed with molten cast iron. A Boston gentleman discovered the method, which con- sists of writing backwards upon ordinary paper with pre- pared ink, and from right to left, instead of the usual way. The paper is fastened to the mould surface and the metal poured over. The paper burns away of course, but the carbon ink resists the action of the molten iron and leaves an indented impression of the writing upon it. See Em- broidery Impressions in Oast Iron. Hard Alloy.— It is claimed that if an alloy is made from 4 copper, 7 zinc, and 1 tin, it will resist all attempts at turning; but if petroleum is used freely the alloy will yield at once to the tools. See Brass ; Speculum Metal. Hard Brass. — Copper 100, tin 10, zinc 5. See Brass ; Speculum Metal. Hardening Metals.— The processes for hardening or tempering the several metals are various. Steel is won- derfully affected by heating and then plunging into water, being so susceptible to this process that almost any degree of hardness may be obtained, and it may again be made soft and malleable, as before, by reheating and allowing it to slowly cool. To harden cast iron, use a liquid made as follows : Soft water 10 gallons, salt 1 peck, oil of vitriol i pint, saltpetre Hardness of Minerals. 200 Hard Plaster. \ pound, prussiate of potash \ pound, cyanide of potash \ pound. Heat the cast iron cherry-red, and dip as usual, repeating the process if wanted harder. Wrought iron is surface-hardened by heating to a bright red, sprinkling with prussiate of potash, and plunging into cold water when it has cooled to a very dull red. See Metals; Tempering. ' Hardness of Minerals. — The hardness of miner- als, beginning with the hardest, is as follows : Diamond 1, corundum 2, sapphire 3, topaz 4, quartz 5, feldspar 6, scapolite 1, apatite 8, fluor-spar 9, calcareous spar 10, gyp- sum 11, talc 12. See Precious Stones. Hardness of Precious Stones.— See Precious Stones. Hard Pig-iron is distinguished by showing at the fracture a dull, grayish-white color, flaky in appearance, with more or less mottle. An extreme degree of hardness exists when the fracture shows a highly crystalline nature, with long, needle-like crystals radiating, and no appear- ance of graphite. See Oast Iron ; Grading Pig-iron ; Soft Pig-iron. Hard Plaster is made by saturating pieces of freshly calcined plaster with water that holds in solution 12 per cent of alum. After thorough saturation the pieces are lifted from the liquid, dried, and calcined at a red heat; after which they are pulverized and sifted, and the plaster is fit for mixing. This plaster requires only about one half of the water used for the ordinary material, but is much longer in setting. When set, this hard plaster is about 50 per cent stronger than the common, and produces a fine, polished surface. See Plaster. Hardware. 201 Hay-rope Twister. Hardware. — A common term for such manufactures as are produced from the useful metals, iron, steel, copper, zinc, tin, brass, and some of the commoner kinds of plated goods. See Metals; Brass; Britannia Metal. Hay Rope. — Hay twisted into rope to any desired thickness, and used for wrapping core-barrels before the clay and loam is applied, its purpose beiog to cover the vent-holes in the barrel, and at the same time serve as a medium for carrying the loam. When the molten metal covers the core, the gases generated in the sand enter the hay rope and pass into the barrel through the vent-holes provided. Strata, and meadow as well as prairie hay, are also employed for making these ropes. See Core-barrel; Ordkance; Hay-rope Twister. Hay-rope Twister. — A machine for spinning hay or straw ropes. Formerly rope-spinning was a tedious opera- tion, consisting of a simple hooked crank which an assist- ant turned in his hands, gradually walking backward as the hay was paid out by the skilful hands of the operator, who sat behind a loose pile of damp hay or straw, and fed it in just such quantity as would produce the thick- ness of rope required. The machine hay-rope twisters now becoming general for this purpose are of various designs. The following is a full description of a power twister: It is constructed of the most approved design, of the best material, and the workmanship is first-class. The bearings of the revolving frame turn upon stout iron standards, which rest on heavy wooden skids, two inches by eight inches. The winding pulley is propelled backward and forward by cog-gearing on a right-and-left screw, which reverses by a spring arrangement at each end of same. Hay-rope Twister. 202 Hay-rope Twister. An operator feeds hay into the hollow spindle, which directs the rope on its way to the reel. As the rope is twisted by the revolving frame, it is fed on the spool by the operator pressing his foot gently on the treadle, reliev- ing it as soon as the rope is wound, and spinning and feed- ing together. The rope can be made tighter or looser according to the tension placed on it by the operator, care being taken when the hay or straw is weak in quality. Great skill is acquired by practice, and beginners must not be discouraged by breaking the rope or other mis- haps. The machine should make about two hundred revolu- tions per minute or faster for small rope, which varies from say one-half inch up to one and one-half inches, depending upon the body of material fed by operator. Each reel will contain about one thousand feet of rope on an average, and from five to ten reels can be spun in a day, according to size of rope, which is a large produce for a smart boy. This machine must be belted to run from right to left at the feeding end, so as to twist the rope right-handed. In securing the twister to the floor, care must be taken not to bolt it in such a way as to cause the frame to bind in its bearings. The reels or spools when full should be removed and sent to the foundry, where they are dropped in a frame and unwound directly on the core-barrels. A sufficient length of rope is allowed to remain on the machine to begin an- other reel with, say, six or eight feet — enough to fasten to the body of the reel. Dimensions. — Extreme length, 6 ft. ; extreme height, 2 ft. 10 in.; extreme width, 2 ft. 6 in.; weight, 750 lbs.; ship- ping weight, 850 lbs. Adaptation. — Motion of reel, rignt to left ; capacity of reel, about 1000 feet of rope; product, 5 to 10 reels per Head. 203 Heat. day, according to size of rope and skill of operator; sizes of rope, i in. to 1J in. Head.— An extension added tc the top end of a casting when the mould is poured in a vertical position and it is desired to obtain a surface that is free from scum and dirt. The sullage is pushed beyond the limits of the casting, lodging in the '? head," leaving the former clean. Another form of riser is one into which the metal is forced by head pressure after the mould is full, and may, if placed on the top, answer as a dirt receiver, or serve as a means for feeding. See Eiser. Heap-sand.— The common sand on the foundry floor. When a moulder is using a certain quantity of sand every day for filling a set number of flasks with, he usually col- lects it in a heap close by, and designates it as heap-sand ; in contradistinction to the facing-sand or new-sand em- ployed in the immediate vicinity of his pattern. See Floor-sand; Old-sand; Facing-sand. Hearth is that part of a smelting-furnace where the ore accumulates and is finally separated from the impuri- ties which may be present in the ores. It is situated at the bottom of the furnace, a little above the mouth of the tuyeres. The term is also applied to the bottoms of finery, open-hearth, and reverberatory furnaces, where the metal is exposed to the action of fire. See Blast-furnace. Heart-trowel.— A moulder's tool with a heart-shaped blade. When, instead of a handle, another tool is forged at the opposite end, it is called a double-end, and may be used at either end as occasion requires. See Moulding- tools. Heat.— We experience the sensation of heat when we Heat. 204 Heat. approach a warm body. The opposite of heat is cold, which merely implies a greater or less deficiency of heat. The two kinds of heat, which are called free, or sensible, and latent, are represented by fire and ice; the free, as in fire, can be felt, while that in ice is latent and cannot be felt. There is heat in all substances, but in those which are called cold it exists in an inferior degree. Some think that heat is not a material substance, but results from the vibrations of the particles of bodies ; others believe it to be an exceedingly subtle substance, whose particles repel each other and thus give it a tendency to diffuse itself while they have a strong affinity for other matter. It would ap- pear that heat is closely connected with light, as the one is generally accompanied by the other. That heat has no weight is proved by weighing a piece of ice, and then melt- ing it, the water produced will weigh the same as the ice. The chief sources of heat are the sun, chemical and mechan- ical action, and electricity. Many speculations have been indulged in as to what composes the sun, that it should continue to give undiminished heat without exhausting the material by which it is supported. That chemical action is a source of heat, may be demonstrated by combining two or more substances to produce a new substance totally dif- ferent in its nature from either; an increase of temperature alway accompanies such action, as maybe proved by mixing sulphuric acid and water in equal quantities; it forms a new substance and gives off heat. Combustion is a chem- ical union of the oxygen of the atmosphere with the com- bustible body, or some of its elements. Animal heat is produced by a similar process: when we breathe air is drawn into the lungs, where it comes in contact with the part- icles of carbon contained in the blood; there is then a chemical union of the carbon with the oxygen of the air inhaled, and, as in the case of combustion, latent heat is evolved. Friction, percussion, and compression are illustra- Height of Cupola. 205 Herbertz Steam jet Cupola. tions, showing that mechanical action is a source of heat; and electricity is conclusively shown to be another source of heat, as the heat produced by its action will melt almost any known substance. See Combustion ; Temperature. Height of Cupola. — What is commonly understood to be the height of a cupola is the distance from the bottom up to the lower edge of the charging-hole. When it is desired to obtain the best results when melting with hard coal or coke, the height for all cupolas up to fifty inches diameter should be at least five diameters ; but when the diameter exceeds fifty inches, the height may be four diameters from the bottom to the lower edge of the charg- ing-hole. See Cupola ; Charging the Common Cupola. Helper is one who assists a mechanic or artist in the regular routine of his work, the more laborious and simple duties being his especial work, for which reason he is usual- ly recognized as an unskilled laborer. Hematite. — A valuable iron ore, consisting chiefly of peroxide of iron. It occurs in large quantities, its two chief varieties being red and brown hematite. An earthy kind, called iron-froth, consists almost entirely of iron. Brown hematite contains about 14 per cent of water. See Eed Hematite. Hemp Rope. — A thin hemp band is sometimes wrapped on core-barrels in place of hay or straw rope when it is desired to obtain a greater thickness of loam than would be possible if either of those materials were employed. See Core-barrel ; Hay Rope ; Ordnance ; Rope. Herbertz Steara-Jet Cupola.— See Steam-jet Cupola. Hessian Crucible. 206 Hoisting-machine. Hessian Crucible. — A triangular-shaped crucible, made from the best fire-clay and coarse sand. They are a cheap kind, and come in nests of sizes from 2 to 8 inches high. They are usually for experimental purposes, and seldom last but once. See Crucible. Hexagon. — A plane figure bounded by six straight lines. When these are equal the hexagon is regular. Hide-faced Hammers. — Hammers provided with faces of hide, suitable for a variety of uses, but especially valuable where light, thin castings are made from iron or brass patterns. Hinged Flasks are flasks operated by hinges fixed on their sides or ends instead of slides or pins, making it only necessary to elevate one side or end in order to sepa- rate the parts. Suitable hinges of a self-adjustable kind, if properly secured in their respective positions, are a posi- tive fit, and never get out of order. Flasks, paired with hinges, require less space to operate them in, and are valuable in small foundries where it would be impossible to lift large flasks entirely oil the joint. Resting in hinges, they may be separated very effectively with half the force required by the common methods. See Flasks. Hoisting-block. — See Hoisting-machike. Hoisting-machine is a convenient hoisting-block, very handy for use in places remote from the crane. The Weston differential pulley-blocks lift from -J- to 10 tons, and with them one man may lift from 1000 to 5000 pounds, according to the kind of block employed. The load is held at any point and cannot run down, thus preventing all danger from accident by that source. See Ceake. Hole. 207 Hollow- ware Moulding. Hole. — A foundry term for a pit or trench dug in the sand floor, in which to mould a casting by the bedding-in process. Such a hole takes the place of cheeks and nowel parts of the flask. See Bedding in ; Pit. Hollow Metal Castings. — Hollow or shell cast- ings, in lead, tin, zinc, and their alloys, are obtained by using a brass mould, which is filled with metal, and, after due time has beeu allowed for a skin to congeal on the surface, inverted, to allow the molten portion to escape. What remains, forms a crust of metal answering to the form of the mould. See Statuary-founding. Hollow Shot are made similar to other hollow cast- ings, except that the flasks containing the moulds are re- versed a few times immediately the gates have set. This forces the fluid iron equally against the sides both in top and bottom parts, prevents flattening of the top side, and thus preserves a true spherical form in the casting. The same with solid shot: the moulds are reversed as soon as possible, which allows the fluid metal to first congeal on the sides and the shrinkage to be made good from the more fluid mass inside the ball, which naturally leaves the centre in a spongy condition, yet is preferable to a flattened upper surface. See Shot ; Projectiles ; Feeding. Hollow-ware Moulding is not necessarily differ- ent from the moulding of other fine objects so far as the processes are concerned. This class of moulding is es- pecially confined to boilers, pots, pans, kettles, including all those cast vessels for domestic use. Owing to the neces- sity of having most of these patterns and flasks in sections, considerable ingenuity is exercised in their arrangement, and the patterns, usually of iron or brass, are elegantly fitted together and finished. The iron part-flasks are, in Homogeneous. ^uo Hood. some instances, marvels of ingenuity ; the system of pins, latches, clamps, and runners being well worthy of copying by founders engaged in the production of castings that are similar in design and only differ in name. Homogeneous. — Of the same kind or nature; hav- ing similar parts; or, of elements of the like nature; as, homogeneous particles, elements, or principles; homogene- ous bodies. Honeycombing is the peculiar phenomena present in the upper portion of cast-steel ingots and steel castings, as well as those of brass and cast iron. In some instances this is supposed to be due to the liberation of imprisoned gases which, for the lack of pressure, remain within the mass of metal and form the honeycombing structure seen. Many schemes have been tried to prevent this, such as regulating the speed of pouring, temperature of metal for pouring with, covering the top with sand, molten slag, etc. ; also by the introduction of some alloy, as aluminum; but none of these seem to be as effective for this purpose as the method pursued by Sir Joseph Whitworth, which consists of sub- mitting the fluid metal to an enormous hydraulic pressure, which is maintained until the ingot has solidified. Some of the aluminum alloys have been credited with the ability to render steel castings perfectly sound, besides making the resultant steel tougher. Some claim that by using this alloy manganese can be discarded and time and fuel saved. See Pressing Fluid Steel; Ingots; Blisters; Blow-holes; Aluminum; Silicon. Hood is all that portion of the cupola shell which extends above the charging-hole. It is best to contract the hood in size somewhat, and carry it up sufficiently high to induce a good draught, which not only serves a good pur- Hook. 209 Horizontal Casting. pose in lighting up the first charges of fuel, but is a considerable auxiliary to the blower. See Cupola; Light- ing the Cupola. Hook. — A forged piece of iron bent into a suitable curve for some purpose of catching, holding, or sustaining; such as the crane-hook, sling-hook, chain-hook, changing- hook, etc. The importance of making all such hooks well and of good material will suggest itself to those who know the risks which are taken daily in the foundry and else- where by men who must necessarily pass under and work in close proximity to loads suspended thereon. See Chain; Cranes. Hook-bolt. — A bolt, one end of which is threaded for a nut, the other turned as a hook, and used for various purposes in the foundry, such as binding portions of loam and dry-sand moulds together, anchoring cores in lower moulds, and suspending them in covering-plates and copes. See Anchor. Hoop-binder. — A substitute for the binding-plate in a brick cope, consisting of a length of hoop-iron with which to tie the course of brick. These may be used for ordinary purposes instead of binding-plates by turning a hook on each end of the hoop-iron, the hooks to meet within four inches round the brickwork, to be there tied with a few laps of softened wire, and brought up close by inserting a small pointed bar between the strands of wire and twisting them one on another. Another method is to rivet lugs on the ends and draw them together by means of a bolt. See Binding-plate; Cope. Horizontal Casting. — When a casting is poured endwise in the pit, it is cast vertically; if the same casting is poured flat on the floor, it is then cast horizontally. Horn-gate. 210 Hot and Cold Blast. Horn-gate. —See Fountain-runner. Horn - quicksilver. — The native subchloride of mercury. It occurs in the mines of Idria in Carniola, and Almaden in Spain. See Mercury. Horse. — A common term for the trestle or stands used for blocking moulds in the foundry. See Stands; Trestle. Horse-manure. — A means for conveying gases from the loam used for building and coating the moulds and cores. The quality of sands and mixtures emp^ed for this purpose is necessarily hard aud unyielding, having little porosity, and must therefore be rendered porous by artificial means. Besides imparting porosity, the manure possesses a quality of stickiness which renders the sand or loam more cohesive, and it is for this reason that it is to be preferred to other substances, as coke-dust, sawdust, etc., which are frequently used for this purpose. See Loam ; Facing-sand; Venting. Hose. — A flexible pipe, made of rubber, leather, and various other flexible materials, for conveying fluids, espe_ cially water. When of good quality and properly cared for by providing reels to wind them on when not in use, and paying strict attention to the joints, they are a great help in the foundry, saving much time in carrying water to and fro. Hot and Cold Blast. — When the stream of air forced through a furnace is drawn direct from the atmos- phere, it is called cold-blast; when it is heated to 500° be- fore it enters the furnace, it is called hot-blast. The com- bustible gases which come from the stack are invariably House bells. 211 Hydraulics. used to heat the air in a kind of oven built near the top of the stack, and surmounted by a chimney which draws off some portion. In this oven a series of pipes are built, around which the fire plays whilst the air is being forced through them before it enters the furnace. A considerable saving of heat is effected by this method, the reduction of the most refractory ores being accomplished in less time and with a less expenditure for fuel than the cold blast. As the melting metal necessarily comes in contact with less fuel, and as a less quantity of air enters the furnace, the chemical reactions are somewhat modified, but there does not seem to be any appreciable difference in the quality of the product. See Blast-furnace; Blast. House-bells. — A special mixture for this class of bells is copper 77, tin 21, antimony 2. See Bell-metal; Brass. Hundredweight signifies a weight of 112 lbs. avoir- dupois. Twenty of these, or 2240 lbs., make one ton. This weight is expressed by the abbreviation cwt. See Ton. Hydraulic Casting-press. — Used for the produc- tion of homogeneous steel. See Honeycombing ; Com- pressed Castings. Hydraulic Crane. — Invented by Sir William Arm- strong in 1846, who erected the first in Newcastle-on-Tyne. These cranes have come into very extensive use where water under sufficient pressure is available. But it would seem that the latter condition is now made unnecessary by the invention of the steam hydraulic crane. See Cranes. Hydraulics. — The science of hydraulics treats of liquids in motion, whether issuing from orifices, or running in pipes or the beds of streams. If an opening be made in Hydrocarbon Furnace. 212 Hydrogen. the side or bottom of a vessel containing a liquid, as molten metal, etc., the latter will at once be forced through it, as the particles at that point are acted upon by the pressure of those above. The rapidity of a stream flowing out of an ori- fice depends upon the depth of the latter below the surface of the liquid. A liquid issues from a given orifice with equal velocity as long as the liquid is kept at the same height in the vessel, but if the pressure is diminished by a lack of supply above, the liquid gets lower, with a propor- tionate diminution in the velocity of the stream. The weight of water or molten metal is as the quantity, but the pressure exerted is as the vertical height. Fluids exert an equal pressure in every direction; hence any vessel contain- ing a fluid sustains a pressure equal to as many times the weight of the column of greatest height of that fluid as the area of the vessel is to the sectional area of the column. See Pressure or Molten Metal; Weighting Copes; Hydrostatic Bellows. Hydrocarbon Furnace. — A furnace having spe- cial burners suitable for using liquid fuel. The burners consist of an apparatus which allows a forced jet of air and steam to carry with them a certain quantity of petroleum which is distributed into the furnace in the form of spray, and there burns with an intensity proportionate to the amount of fuel supplied. Hydrogen is the lightest substance known, and pos- sesses nearly all the properties of a non-metal in such per- fection, that chemists have long hesitated to class it with the metals, though its chemical relations clearly show it to belong to that class of elements. It combines with nearly every non-metal, but with only two or three of the metals. Hydrogen is colorless, tasteless, and inodorous when quite pure. It is inflammable, and burns with a pale Hydrostatic Balance. 213 Hydrostatic Bellows yellowish flame, evolving much heat but very little light. The result of the combustion is water. It has never been liquefied, and is even less soluble in water than oxygen. It is incapable of sustaining life, but contains no poisonous properties. Hydrogen is never found free in nature, but exists abundantly in combination, forming one ninth by weight of water, and a considerable proportion of all organ- ized substances. It is the lightest of all known substances, being 16 times lighter than oxygen and 14J- times lighter than air; its density is placed at 0.0692 referred to that of air as unity, 100 cubic inches weighing about 2.14 grains. Hydrostatic Balance.— A specific-gravity balance. See Specific Geavity; Specific-geayitt Balance. Hydrostatic Bellows is an apparatus which serves to explain that peculiar property of liquids, including molten iron, in virtue of which they transmit pressure in every direction. The hydrostatic bellows consists of two boards held to- gether by a band of rubber, which allows a bellows motion to take place when force is applied inside. These form an absolutely tight chamber, to which a small tube is attached by inserting it in the top side. The water is poured down the tube, and as the chamber fills the upper board rises with the pressure. If the surface of the board is fifty times as large as the end of the tube, one pound of water will balance fifty pounds of weight on the board. Because the surface of the cover is fifty times larger than the orifice of the tube, there are fifty times as many particles of water in contact with the board as there are at the end of the tube, and as each particle throughout the whole surface is made to exert the same pressure, one pound of water in the tube should balance fifty pounds on the board. If the moulder who may be unacquainted with these sub- Igneous Bocks. 214 Impressions on Cast iron. jects will carefully examine this apparent paradox, and in his mind substitute for the tube a down-runner leading to a mould below, in which molten metal instead of water is to be poured, he will at once discover that the only differ- ence betwixt the two is the difference in weight of the water and the metal. This will enable him to realize why so small a runner will lift such a great weight. See Weight- ing Copes ; Pressure of Molten Metal. Igneous Rocks include granitic, trappean, and vol- canic series, all of which rocks have been produced by fusion, on the surface, or in the interior, of the earth's crust. See Eock. Imitation Gold. — An alloy of baser metals which produces a yellow compound metal resembling gold. See Gold Alloy; Tombac. Imitation Silver. — An alloy of metals for manu- facturing articles of jewelry, etc., in artificial silver. An alloy having the same specific gravity as silver consists of : copper 11.71, platinum 2.4, silver 3.53. The following is a beautiful imitation silver that retains its brilliancy : Tin 4§, bismuth J, antimony -|, lead \. Many other alloys of this description are given under their respective heads. See Silver Alloys; Mock Sil- ver; German-silver; Tombac. Impact. — An instantaneous blow communicated from a moving body to another body either moviug or at rest. Impressions on Cast Iron.— See Embroidery Impurities in Cast Iron. 215 India Cast Steel. Impressions on Cast Iron ; Handwriting Impres- sions in Cast Iron. Impurities in Cast Iron.— The chief impurities contained in cast iron are manganese, sulphur, phosphorus, and silicon. Manganese tends to the formation of com- bined carbon, reduces tensile strength, produces brittle- ness, and makes slag. Except in very strong castings, manganese should not exceed 0.5 per cent of the mixture. Sulphur contributes to retain the carbon in the combined state, and promotes the formation of combined carbon. Foundry irons should not contain more than 0.1 per cent of this element. Phosphorus causes hardness by lowering the separation of graphite, but increases fluidity. From 0.3 to 0.5 per cent of this element is all that should be al- lowed in foundry mixtures, unless cases where great fluid- ity, regardless of strength, is the chief desideratum. Sili- con increases fluidity, reduces hardness and shrinkage, by changing combined into graphitic carbon. Any addition of silicon after the bulk of the carbon has become gra- phitic hardens the casting. Cast-iron mixtures may con- tain from 1.75 to 2.5 per cent of silicon. See Cast Iron; Silicon; Softeners. Incoherent . — Wanting in coherence or cohesion ; unconnected; loose, not joined to each other, as the par- ticles in free sand. Incombustible.— Cannot be decomposed, burned, or consumed by fire. See Kefractory Materials. India Cast Steel is a species of steel of extraordi- nary quality, and commonly culled Wootz steel. It is im- ported into this country and Europe for the manufacture of fine edge instruments, etc. It is said that the cele- India-rubber. 216 India-rubber. brated Damascus blades were made of it. The process of making consists of melting small pieces of wrought iron, mixed with some twigs and dried mould, covered up well with green leaves, and luted. The crucibles are built in the form of a pyramid, inside the furnace, and exposed to a strong heat. The pieces of wootz, about as big as a wal- nut, are not disturbed until the crucible has cooled. The metal contains traces of silica and alumina, and about the maximum amount of carbon ordinarily found in steel. Wootz has been known throughout the East from remote antiquity. See Steel. India-rubber, or Gum-elastic, is the dried juice of tropical plants. It has a close resemblance to some of the gum resins, but differs from them in that the latter do not contain caoutchouc. This remarkable gum is supposed to have been discovered by a voyager on the second expedition of Columbus, who saw some natives of Hayti playing games with balls made from elastic gum. The india-rubber in- dustry began in earnest about the beginning of the eigh- teenth century on a very small scale, but in 1870 there were nearly 200 manufactories in America and Europe, who consumed annually more than ten million pounds of caoutchouc. India-rubber is composed of hydrogen and carbon. Dilute acids or alkalies do not act upon the gum; but it is oxidized and destroyed by concentrated nitric acid, and charred with strong, hot sulphuric acid. It is dissolved, more or less perfectly, in melted naphthaline, benzol, bisulphide of carbon, petroleum, and the oils, both fixed and volatile. It fuses at 250° F. Mr. Goodyear in- vented the system of vulcanizing this gum by incorporat- ing with it from 2 to 3 per cent of sulphur, which increases its elasticity and prevents it from adhering to the moulds when subjected to pressure. Carbonate of lead and nu- merous other substances are also added to india-rubber Indigo- copper. 217 Ingot. for the manufacture of some special goods. If immersed in fused sulphur at 250° F., india-rubber absorbs 15 per cent of the sulphur and is not materially changed. If, however, it be now subjected for an hour to a temperature of 300° F., combination takes place, and vulcanized caout- chouc is the result. A further increase of temperature changes it to ebonite, or black vulcanite, a substance in great demand for the manufacture of countless articles in every-day use. If the sulphur be first dissolved in oil of turpentine, and this used for dissolving the india-rubber, the mixture remaining (after the turpentine has evapo- rated) will be india-rubber and sulphur, which substance can be readily pressed into plaster or metal moulds of any desired form, and the articles then vulcanized by subject- ing them for an hour to a temperature of 280° F. in a closed iron vessel into which steam at high pressure is ad- mitted. See Kesln". Indigo - copper. — A native sulphuret of copper, generally found uncrystallized, but sometimes occurring in hexagonal crystals. Its color is indigo-blue ; contains cop- per 66.5, sulphur 33.5 ; specific gravity 4.6. It is found iu the lava of Vesuvius, Bolivia, and Chili. See Copper. Infusible. — Cannot be melted, dissolved, or infused. Proof against fusion, as an infusible sand or crucible. See Refractory Materials. Ingate.— See Gate. Ingot. — A mass of metal which has been cast in a suit- able mould for convenience in subsequent working by the various processes of rolling, hammering, casting, etc. ; some consideration is also given to the best forms for ship- ping, etc. Copper is made into bricks and pigs; tin into Ingot. 2l8 Ingot. blocks ; zinc into cakes. These are all run into metal moulds which give them their respective shapes. The blocks of commercial gold and silver are called Mrs. Cast iron is run direct from the smelting-furnace into moulds formed in an adjacent sand-bed, the product being pigs. Running or " teeming " steel ingots, produced by melt- ing blister-steel in crucibles, or from steel prepared by melting puddled steel with spiegeleisen or black oxide of manganese, if the ingots are small, is usually done by hand, by simply emptying the contents of the crucible direct into the cast-iron ingot-mould. If one crucible is insufficient to fill the mould the pots are doubled, that is, two crucibles are emptied into one larger, so that the one operation suf- fices ; but in larger-sized ingots it is often necessary to em- ploy two streams in order to secure an uninterrupted flow of steel into the mould. Extra-large ingots, made from this class of steel, are often run from one ladle by simply melting all the steel in the several crucibles and emptying their contents therein. The ladle employed for this pur- pose is clay or brick lined, and provided with a nozzle at the bottom, in which a gannister plug or stopper is fitted. This stopper is connected with a vertical rod attached to the arm for raising and lowering the stopper ; the rod itself being inside the ladle, is necessarily coated with about 1J inches of the gannister composition also. By this means a continuous stream of molten steel is delivered, clear of the mould sides, and without fear of intermission until the space is filled. This ladle, as just described, is the one used for running the steel ingots produced by the Bessemer process, only in this instance it is suspended on an arm which extends from the head of the hydraulic crane in the centre of the casting- pit. The ingot-moulds, being arranged in order around the outer diameter of this pit, are filled in succession by simply bringing the ladle directly over and allowing them to fngot. 219 Ingot. fill by withdrawing the plug at the bottom. Sometimes these ingots are cast in groups arranged round a central one that is placed higher than the rest, and connected with the latter by means of a system of fire-clay runners which radiate from the central ingot, at the bottom, to as many as may be grouped around it. The steel in this case enters the central ingot at the top, and gradually fills all the rest from the bottom. Very large ingots, which are sometimes over 20 feet long and may weigh from 14 tons up, are preferably cast from the bottom, and suitable provision is made by forming a fountain-runner within a core made from a gannister and fire-clay mixture, which is set in the prepared bottom of the mould. One end of this runner extends past the ingot- casing, and is connected with a vertical cast-iron and gan- nister-lined runner-box, which, resting thereon, is made to project somewhat above the top of the ingot-casing. This casing usually consists of two wrought or cast iron half- circles, protected by a fire-brick lining coated with some refractory composition. These halves, when duly prepared, are bolted together, with a loam packing between the join- ing flanges, and then brought into a vertical position for setting down, on a soft loam packing also, upon the lower portion of mould already in the pit. Ingots of even larger dimensions are often made with a central core. Owing to the intense heat to which these cores are sub- jected, the ordinary preparations are simply valueless, as they are sure to be melted. To overcome this difficulty, the cores are made in one or more lengths, as desired, by ramming composition sand of a very refractory nature around an ordinary cage core-iron, the cast rings of which are not permitted to approach the surface by at least two inches. By this means a core is obtained containing the smallest amount of iron possible in its construction; in fact it is, literally, a sand-core almost free from substances which Ingot-mould. 220 Intaglio. would be likely to melt. All such ingots are invariably run at the bottom. See Pressing Fluid Steel ; Reeking Ingot-moulds ; Running Steel Ingots. Ingot-mould. — The metal, sand, or fire-brick moulds in which metals are cast to form ingots suitable for manu- facturing and commercial purposes. The brass-founder's ingot-moulds are of cast iron, about two feet long and wide enough to form three tapered ingots 7 by 2 inches, or of a size suitable for stowing in the crucible for remel't- ing. The webs which divide such an ingot-mould into three are notched at the top, midway; this allows of each mould being filled without removing the crucible from that in which the metal is poured. See Ingot; Brass Scraps; Brass. Insect Casts in Metal.— To produce a perfect cast of an insect, animal, or vegetable in metal, it is only necessary to obtain a box large enough to hold whatever it is desired to produce, with a little space to spare. After suspending the object with strings in a suitable position, attach the vents and pouring-gate, and fill the space with a composition made from plaster of Paris 2 parts, and finely ground brick-dust or talc 1 part. The operation must be carefully performed. The whole is then gently dried, and afterwards made red-hot so as to reduce to fine ashes whatever was placed therein. The vents, being placed at all the extremities, are of assistance in blowing the ashes out at the running-gate, and these in conjunction with the holes made by the strings will permit all gas to escape when the metal is poured in at the gate. A good alloy for small objects cast after this manner is tin 6, lead 3, bismuth 2. Intaglio. — A kind of engraving distinguished from Iridium. 221 Iron Alloys. cameo by having the engraved figures sunk into the sub- stance instead of being raised in relief. Seals and other similar articles are engraved thus. See Eilievo. Iridium. — A white brittle metal, which may be fused by means of a powerful oxyhydrogen blast-furnace. In its isolated form it is unacted upon by any acid or by aqua regia, but as an alloy it is dissolved in the latter fluid. Its specific gravity is 21.15. An alloy of iridium and osmium is very hard, and is used for pointing gold pens. See Metals. Iron. — Of all metals iron is the most important. The pure metal is found only in such rare instances as in the case of meteorites which have fallen from space. In South America and elsewhere isolated masses of soft malleable iron have been found loose upon the surface of the earth, and these too would seem to owe their origin to the same meteoric source. In these specimens of native metallic iron nickel is usually found. The presence of iron in an oxidized condition is universal : rocks and soils are colored by it, plants contain it, as also does the blood of the human body. Pure iron is very soft and tough, has a specific gravity of 7.8, is white, and has a perfect lustre. It may be observed that there always exists a very distinct fibrous texture in good bar-iron after it has been attacked with acid; the perfection of this fibre is what gives it strength. See Malleable Ikon; Oast Iron; Strength oe Materials. Iron Alloys. — Very few of the metals alloy with cast iron in such a manner as to be of any practical value to the founder. True, there is a marked difference in the resultant mixture by the addition of alloys, but it does not affect them favorably as a rule, By the addition of a Iron Carrier, Foundry. 222 Iron Carrier, Foundry. quarter of one per cent of copper, well stirred into the molten iron, a perceptible increase of density may be noticed, and the strength is increased somewhat. Again, if from 10 to 15 per cent of wrought scraps can be success- fully mixed with the cast iron after the latter has been melted the same improvements are apparent. Much is claimed for the aluminum fluxes now offered, but any opinion as to their worth would, at this early stage of their application, be premature. See Alloys; Aluminum; Gold. Iron Carrier, Foundry. — The Hayes patent carrier for molten metal is described as follows: There is a continuous overhead track, which runs from the cupola to the extreme end of the floors and return. The floor may be of any length; there is no carrying of iron by hand. On this track ladles of any capacity from four hundred to one thousand pounds may be carried. From these large ladles the iron is poured into smaller ones, into hand-ladles, or larger ladles with double handles. A very unique and simple device is used for pouring the iron into the hand-ladles, so that the moulder need not hold the weight of the hand-ladle while the iron is being poured from the large ladle into the small one. The cupola is not stopped up from the time the iron commences to run until all is out. The very unique arrangement of having a catch-ladle which swings into the stream and catches the flowing iron while the exchange of large ladles is being made, saves all the annoyance around the cupola, and catches all the iron. Moulders never need leave their floors. The iron is brought to them by common laboring men. The apparatus is simple, durable, and so perfectly safe that it frees the foundry from the mishaps that often occur by the old methods of distributing iron, Iron Furnace. 223 Isosceles Triangle. Iron Furnace. — A furnace in which some operation connected with the manufacture of cast iron, malleable iron, or steel is conducted ; as cupola, smelting, reverberatory furnaces, etc. The several furnaces employed for this pur- pose will be found described in their regular order. Iron-lustre. — This lustre is obtained by dissolving zinc in muriatic acid, and mixing the solution with spirit of tar. To be applied on the surface of the iron. Iron-statue Moulding. — Moulding statuary in iron. This branch of the art is necessarily more difficult than any other of the processes followed for the produc- tion of statuary in bronze, because the materials used for moulding with are less rigid, and demand more skill in their manipulation as a consequence. The core is built by the moulder, on which the sculptor carves his model in clay or wax, after which the moulder builds his cope around it in sections ; the latter, when sufficiently hardened, are lifted away, the thickness removed, and the whole mould finished, dried, closed together, and cast like any other ordinary piece of loam -work. See Statue-founding. Iron-wire Cloth. — See Wike-cloth. Isinglass. — A very pure form of gelatine prepared from the entrails and air-bladders of fish, notably the stur- geon. It is semi-transparent when pure, and this may perhaps account for applying the name to the sheets of mica employed for sight-holes of cupolas, stoves, etc. Isinglass is an excellent material for making elastic moulds for obtaining plaster casts. See Elastic Moulds. Isosceles Triangle is a triangle which has two equal sides, Ivory-imitation. 224 Japanese Bronze-work. Ivory-imitation. — A good imitation of ivory statu- ettes may be obtained by casting into warm plaster-moulds a mixture composed of finely pulverized egg-shells, isin- glass, and alcohol. See Plaster Casts. Jacket-core. — The core which forms the space be- twixt inner and outer shells of a jacketed casting, as a jacketed cylinder, etc. Sometimes these shells are joined together by studs at intervals, in which case the core must invariably be made in one piece, and veuted at the top through holes purposely made in the casting for this pur- pose, but which are subsequently plugged. If a convenient branch, etc., offers the opportunity for making adequate vent connections, the labor of plugging is saved. When the shells are joined by parallel webs the jacket- core is divided into as many segments as there are webs, and each core is vented separately. In the former case a cage or skeleton core-iron serves to construct the core; the latter needs only a centre web with protruding wings. For constructing a whole jacket-core the dummy-block is a cheap and effective device ; a narrow core-box is all that is necessary for the web-jacket. See Dummy-block-; Skeleton" ; Core-iron ; Venting. Jacketed Cupola.— See Water-jacket Cupola. Japanese Bronze-work.— The art of working in bronze is a very old one in Japan. The whole process of casting is done by the artist himself, who forms his moulds from models designed in a mixture of wax and resin which is melted out of the prepared mould previous to the final pouring of the metal. By this means, castings are obtained Jasper. 225 Jobbing-pipe. of every description, from statues of all sizes down to the most intricate and delicate tracery, which is elaborated with scrupulous care, requiring, in some instances, months to prepare the mould. The Japanese add tin, zinc, lead, and iron to their bell mixtures. Their small bells contain copper 60, tin 24, zinc 9, iron 3. Large bells are composed of copper 60, tin 18, lead 12, zinc 6, iron 3. The mixture is called Kara-Kane. See Bronzes. Jasper. — Like carnelian, agate, and chalcedony, this mineral is chiefly composed of silex, but it always contains more iron, and hence, instead of being translucent, like them, it is always opaque. Its colors are red, yellow, and brown ; specific gravity 2.70. Its composition is silex 75, alumina 0.5, lime 0.02, iron 13. It is infusible. See Precious Stones. Jet-cupola. — See Steam-jet Cupola. Jib-crane.— See Cranes. Jobbing-moulder. — A moulder whose superior at- tainments enable him to mould more than one class of castings. Such qualifications are acquired only by perse- verance and industrious practice in many foundries, which not only differ in the class of castings produced generally, but differ also in their modes of producing the same casting. Moulders that are engaged exclusively on stove-plate, hollow-ware, snap- work, etc., are naturally unable to do this ; hence are distinguished as stove-moulder, hollow- moulder, snap-moulder, etc. See Technical Education for the Moulder. Jobbing-pipe. — A technical term for all pipes that Joint. 226 Kara-Kane. are irregular in form, including elbows, turns, branch, and numerous others, which must of necessity be moulded by such means as are most convenient for the occasion, without reference to cost, etc. Pipes of this character are usually made in the most ap proved fashion by skilled moulders who work by the day ; while the regular trade straight lengths are made, as a rule, by unskilled labor, in vertical casings that are so elaborately mounted as to preclude any possibility of going astray. See Cast-iron Pipes ; JOB- BING-MOULDER. Joint. — A common name for the point of separation in moulds. When two halves of a core are placed together the joining surfaces form the joint ; so in flasks cope and drag meet together at the joint. See Parting. Joint-board.— See Match-board ; Parting. Jonriial-box Metal.— See Anti-friction Metals ; Babbitt Metal ; Brass. K. Kaolin. — A pure white clay resulting from the decom- position of feldspar in granitic rocks. The materials em- ployed by the Chinese for the manufacture of porcelain are known to be kaolin, petuntze, or quartz reduced to a fine powder; and the ashes of fern, which contain potassic carbonate. Kaolin is used extensively for the manufacture of clay crucibles for steel melting, being mixed with equal quan- tities of Stourbridge clay and some old pot and coke-dust. See Crucible; Feldspar. Kara-Kane. — The name given by the Japanese to their celebrated bronze mixtures for bells. See Japanese Bronze-work. Keep's Testing-machine. 227 Kiln. Keep's Testing - machine. — See Testing-ma- chines. Keim's Water-jacketed Cupola, jacketed Cupola. -See "Water- Kettle. — A vessel of iron or other metal used for the purpose of heating or boiling liquids, or melting metals. The common method of moulding a kettle with the spindle and sweep-board is to first strike a core, answering to the inside, upon a foundation-plate ; then strike a sand thick- ness over it corresponding to the outside, the impression of which is taken in the cope built on a surrounding cope- ring that bears the whole outside structure. After separa- tion, the thickness is removed and moulds finished, when the cope is returned to its place, and, after due prepara- tion, the space is filled with molten metal. The following table shows the weight of spherically shaped kettles when the depth is equal to half the diameter of core, and one inch thick : Inside di- ameter in inches. 36 42 48 54 60 66 72 78 84 90 96 102 108 114 120 Weight in pounds. 590 791 1022 1281 1570 1889 2237 2614 3021 3457 3923 4418 4492 5496 6079 See Spindle; Sweep-board; Foundation-Plate ; Cope- ring; Thickness; Casino. Kiln. — An oven or stove which may be heated for the purpose of drying, hardening, or burning anything. Kilns are used for roasting or calcining iron ores, with the view of expelling water, sulphur, and volatile or other matters which under the influence of heat, or the combined action of heat and atmospheric air, are capable of volatilization, and to free the ore from these constituents and leave it Kish. 228 Lacquering. porous; in which condition it is more readily acted upon by the flame and gases of the blast-furnace. See Cal- cination; Weathering Ores. Kish. — When rich gray iron in a state of fusion is per- mitted to cool very slowly, a graphitic substance, resembling plumbago, gradually separates itself from the molten mass. This substance is called Tcish, and is composed of carbon, sulphur, and manganese in varying proportions. This phe- nomenon evidences the inability of the metal to hold as much carbon, etc., in solution at a low temperature as at a greater heat. The same metal, if run into moulds at a greater heat, and allowed to solidify rapidly, would retain the most of this carbon either in the graphitic or combined state, or both. See Graphite in Pig-iron ; Cast Iron. Krupp's Crucibles for Steel.— See Crucibles. Kustitien's Tinning Metal. — Malleable iron 1 pound; heat to whiteness; add 5 ounces of antimony, and tin 24 pounds. See Tinning. Laboratory. — A place where operations and experi- ments in chemistry, pharmacy, pyrotechny, etc., are per- formed. Lac.— See Shell-lac. Lace Impressions on Cast Iron. — See Em- broidery Impressions on Cast Iron ; Handwriting Impressions on Cast Iron. Lacquering. — Lacquers are varnishes applied upon brass, tin, and other metals to prevent fhem from tarnish- Lacquering. 229 Lacquering. ing, and should always be applied soon after the process of bronzing or dipping. Their basis is a solution of seed-lac in alcohol. About 3 ounces of powdered shell-lac are added to a pint of the spirit, and the mixture allowed to digest with a moderate heat. The liquor, after being cleared by- settling, is strained and poured off, and is then ready to receive the required coloring substances, the chief of which are annotto, dragon's-blood, gamboge, saffron, and turmeric. If the brass or other metal to be lacquered be old and dirty, make a strong lye of wood-ashes, which may be strengthened by soap-lees; put in the old brass-work, and the original lacquer and dirt will fall off. It must then be immersed in a mixture of nitric acid and water strong enough to eradicate the dirt ; after which, wash in clean water, and it is ready for the lacquer. If the work is new, take off the dust and polish with chamois leather before applying the lacquer. The work to be lacquered must be subjected to a moderate heat; then, holding it in the pincers, apply the preparation with a soft brush, tak- ing pains to cover the whole surface by a gentle pressure of the brush in one direction. The following are some mixtures for lacquers : Gold Lacquer. — Seed-lac, 3 ounces ; turmeric, 1 ounce ; dragonVblood, \ ounce ; alcohol, 1 pint. Digest for a week, frequently shaking ; decant and filter. Dark Gold Lacquer. — Strongest alcohol, 4 ounces; Span- ish annotto, 8 grains ; powdered turmeric, 2 drams; red- sanders, 12 grains. Infuse and add shell-lac, etc., and when dissolved add 30 drops spirits of turpentine. Brass Lacquer. — Shell-lac, 8 ounces; sandarac, 2 ounces; annotto, 2 ounces; dragon's-blood, J ounce; spirits of wine, 1 gallon. Bronzed Dijjped Work. — Alcohol, 12 gallons ; seed-lac, 9 Lacquering. 230 Lacquering. pounds; turmeric, 1 pound to the gallon; Spanish saffron, 4 ounces. If for a light lacquer, the saffron may be omitted. Tin-plate Lacquer. — Alcohol, 8 ounces; turmeric, 4 drams; hay-saffron, 2 scruples; dragon's-blood, 4 scruples; red-sanders, 1 scruple; shell-lac, 1 ounce; gum-sandarac, 2 drams ; gum-mastic, 2 drams ; Canada balsam, 2 drams; when dissolved add spirits of turpentine, 80 drops. Iron Lacquer. — Amber, 12; turpentine, 12; resin, 2; asphaltum, 2; drying oil, 6. Iron Lacquer. — Asphaltum, 3 pounds; shell-lac, \ pound ; turpentine, 1 gallon. Red Lacquer. — Spirits of wine, 2 gallons; dragon's-blood, 1 pound ; Spanish annotto, 3 pounds ; gum-sandarac, 4|- pounds; turpentine, 2 pints. Made as pale brass lacquer. Pale Brass Lacquer. — Spirits of wine, 2 gallons ; Cape aloes, 3 ounces; fine pale shell-lac, 1 pound; gamboge (cut small), 1 ounce. Digest for a week, shake frequently, de- cant, and filter. Pale Tin Lacquer. — Strongest alcohol, 4 ounces ; pow- dered turmeric, 2 drams; hay-saffron, 1 scruple ; dragon's- blood in powder, 2 scruples ; red-sanders, -§- scruple. In- fuse this mixture in the cold for 48. hours, pour off the clear and strain the rest ; then add powdered shell-lac, \ ounce; sandarac, 1 dram; mastic, 1 dram; Canada balsam, 1 dram. Dissolve this in the cold by frequent agitation, laying the bottle on its side to present a greater surface to the alcohol. When dissolved, add 40 drops of spirits of turpentine. Lacquers of Various Tints. — To 32 ounces of spirits of turpentine add 4 ounces of the best gum-gamboge, to the same quantity of spirits of turpentine add 4 ounces of dragon's-blood, and to 8 ounces of the same spirits add 1 ounce of annotto. The three mixtures, made in separate vessels, should be kept warm, and as much as possible in Ladles. 231 Ladles. the sun, for three weeks, at the end of which time they will be fit for use ; and any desired tints may be obtained by making a composition from them with such proportions of each liquor as the nature of the colors desired will point out. Ladles. — The business of making foundry ladles has, virtually, been monopolized by the numerous manufactur- ers of these and other foundry supplies, who are ready to supply every description of ladle at prices astonndingly lower than is possible for private firms to produce them — from a small hand-ladle holding 35 pounds, to the more ponderous ones that are controlled with the greatest ease by improved devices, making it possible to operate with the minimum of help even the largest ones. The following table gives depth and diameter, inside the lining, of ladles to hold from 50 pounds to 16 tons : Capacity. Diameter. ' Depth. 16 tons 54 inches. 56 inches. 14 " 52 " 53 « 12 " 49 " 50 " 10 " 46 " 48 « 8 " 43 < < 44 « 6 " 39 " 40 " 4 " 34 " 35 " 3 " 31 ' < 32 « 2 « .... 27 " 28 " 1 " 22 " 22 " i " ..17 " 17 " t " 13J " 13^ « 300 pounds 11J " 11| " 200 " 10 « 10J " 100 « ..8 « 8J " 50 « 6J " 6J " 25 " 5 " 5J " See Lip. Lake Ore-iron. 232 Lead. Lake Ore-iron. — Hydrated peroxide of iron is de- posited in large quantities by certain lakes in Sweden and Norway. It is similar in conrposition to the bog iron-ore found in other parts of Europe. See Bog Iron-ore. Lamellar. — Consisting of thin or extended plates, layers, or scales; distributed or disposed in thin, filmy processes. Lampblack consists of a very fine description of infinitely divided charcoal. It is commonly made by heat- ing in an iron vessel vegetable matters rich in carbon, in- cluding tar and resins, the vapors of which are burnt in a current of air insufficient for complete combustion; conse- quently the hydrogen burns away and leaves the carbon behind in a finely divided condition on the walls of the chamber, which are hung with coarse cloths. Lampblack thus obtained invariably contains more or less unburnt resinous or fatty matters. When it is required to obtain a small quantity of very fine lampblack, it may be done by holding a cold plate over a common gas flame until suffi- cient has been deposited. See Carbon; Charcoal. Lantern. — A term applied to a temporary drying ap- paratus for moulds during their course of construction. It is oftentimes called a lamp or drying-kettle. See Drying- kettle. Lapidary. — One who cuts, polishes, or engraves gems or precious stones. See Precious Stokes. Lead. — Ores of lead occur in great abundance in al- most all parts of the world. They are generally in veins, sometimes in siliceous rocks, sometimes in calcareous rocks. Abundant Scripture testimony proves the existence of this Lead. 233 lead. metal in olden times, and we are informed that the Ro- mans used sheet-lead in the manufacture of water-pipes. The metal is very heavy but soft, is of a bluish-gray color, of great brilliancy. The specific gravity of lead is 11.35, and it melts at 617°. Almost all the lead of commerce is obtained horn galena (sulphide of lead). It is then pickled, broken, and washed, and afterwards roasted, to eliminate the sulphur. Lead is an important metal in the arts. Rolled into sheets it is used for roofing houses, for cis- terns and pipes. It is also of great service in the con- struction of large chambers for the manufacture of sul- phuric acid; its value for making shot is well known. Lead enters into many very useful alloys, as with bis- muth for fusible alloys, with antimony for type-metal, with arsenic for shot, with tin for pewter and solders, with copper for pot-metal — for which compound it cannot be used more than one half lead, as it separates in cooling. With zinc it will scarcely unite, but their union may be brought about by a small proportion of arsenic. Many of the numerous alloys for mechanical and other purposes are improved by certain proportions of lead, and very few mixtures but may be made more fusible, malleable, and sharper in the cast by a slight addition of this metal ; but with gold it forms an alloy of extreme b littleness ; \ of a grain of lead will render an ounce of gold perfectly brittle, although both gold and lead are such soft and ductile metals. The ductility of copper at any temperature is impaired by the use of lead. Alloyed with silver, the metals will separate if slowly cooled from the melting- point. It does not appear that cast iron and lead alloys will answer any useful purpose. Of the compounds of lead other than alloys we have white-lead or carbonate of lead, and red-lead or red oxide of lead, the latter being much used in the manufacture of flint-glass and porcelain. Lead-ladie. 234 leaf Gold. The various alloys of which lead forms a component part will be found under the following heads : Fusible Alloys; Type-metal; Lead-shot; Pewter; Solder; Pot-metal; Bismuth; Antimony; Arsenic; Tin; Cop- per; Alloys; Brass; Anti-friction Metals ; White- lead ; Red-lead. Lead-ladle. — Ladles for melting and pouring lead may be of cast or wrought iron, of any dimension or form best adapted to the purpose for which they are to be used. Lead-pipe. — See Sheet Lead. Lead-shot. — The common method of making small lead-shot is as follows : The melted lead is made to fall through the air from a considerable elevation, and thus leaden rain, as it were, is solidified into leaden hail or shot. The tower in which the manufacture takes place is about 180 feet high, 30 feet diameter at the base, and 15 feet at the top. The melting is conducted at the top in brick furnaces built against the wall, the lead is rained down from a colander, through a central opening into a water- tank below. The size of the shot is regulated by the mesh of the colander, the latter being a hollow hemisphere of sheet iron about 10 inches in diameter. When the shot are taken out of the water they are dried upon metal-plates, that are heated by steam, and the imperfect ones are sepa- rated from those that are spherical. The addition of a slight proportion of arsenic to the lead used for shot helps it to solidify, as well as rendering it more fluid. The alloy for lead -shot is lead 56, arsenic 1. See Lead; Arsenic; Hollow-shot. Leaf Gold.— See Gold. Level. 235 levei*. Level is an instrument used to discover a line parallel to the horizon, and to contiuue it at pleasure. Water-level shows this horizontal line by means of a surface of water or other fluid, found on the principle that water always places itself level or horizontally. The common mason's level consists of a long parallel straight-edged ruler, in the middle of which is fitted, at right angles, another broader one, at the top of which is suspended a plummet, which, when it hangs over the mid- dle line of the upright piece, shows that the base or horizon- tal ruler is level. The spirit-level in common use amongst moulders has brass side-views, brass top, and end-plates and corners, protected by ^-inch-square rods extending the entire length of the rosewood staff. The tube, which con- tains alcohol, is slightly curved, and the straight edge of the instrument is tangent to it. For instructions to level a bed on the foundry floor, see Bed. Lever. — The lever is the simplest of all machines, and is only a straight bar of iron, wood, or other material, sup- ported on and movable round a prop called the fulcrum, and having the weight to be moved and the power to move it applied at two other points. The law is that the poiver and weight are in the inverse ratio of their distances from the fulcrum. This is equally true for straight or bent levers, and holds good whatever be the relative positions of the power, weight, and fulcrum ; and as there can be three different arrangements of these, we thus obtain what are called the three kinds of levers. The first kind is where the fulcrum is placed between the power and the weight; levers of the second kind are those in which the weight is betwixt the power and the fulcrum; in levers of the third kind the power is betwixt the weight and the fulcrum. To produce equilibrium in levers of the first kind, the power may, according to the ratio of the lengths Levigation. 236 Lighting the Cupola. of the arm, be either greater or less than the weight: in the second kind it must always be less, and in the third kind always greater. Levigation.— See Trituration. Lift. — When two parts of a flask are separated the operation is called lifting. Should the separation be a clean one, it is termed a good lift, and a bad lift if much repairing is necessary. When the parting extends much below the joint, it is then a deep lift. See Gaggers ; Chocks ; Parting. Lifter.— See Cleaner. Lifting-tongs. — A form of tongs with which to lift a crucible out of the furnace. They should always be strong, and of various sizes, so that each crucible has its own tongs which grips it closely all round. For large cruci- bles it is preferable to clasp them above and below with tongs that have double prongs, and an eye should be forged on the end of one leg. By this means a small crane may be employed for hoisting out the crucible when full of metal, — a readier and much safer method than struggling to withdraw it by hand. See Crucible. Lighting the Cupola.— Success in cupola-melting depends, to some extent, upon the manner of starting the fire. Carelessness in this particular may result in there being more or less of the fuel in a semi-cold condition ly- ing upon the bottom when the molten iron begins to fall from above. This naturally dulls the iron at the be- ginning, and may exert a bad effect upon the heat all through. It should be the aim of the cupola-man to have a clear, bright fire upon the bed before the blast is admit- ted, so that hot fluid metal will show at the first tap. In Lighting the Cupola. 237 Lighting the Cupola. order to accomplish this, some attention should be paid to the kind of wood used for kindling with, as well as to the manner of distributing it at the bottom of the cupola ; short pieces are the best, as they can be arranged with a view to preserving the sand bottom intact ; and, whilst it is absolutely necessary to preserve a good free passage for air, yet it is well to prevent, as much as possible, any of the coal or coke from falling to the bottom before it has become thoroughly ignited. If old wood is used, let it be freed from every particle of sand, otherwise a slaggy bottom is the result from the start. Nails, spikes, and other malle- able-iron fastenings, usually so plentiful in old foundry chips and lumber, should be carefully extracted before such wood is used for kindling with, as if left in any consider- able quantity the nature of the iron is changed for a length of time proportionate to the amount of wrought iron intro- duced. Dirty kindling-wood and rusty nails have much to answer for at some foundries. Intelligent operation will soon discover just how much wood is needed to thoroughly ignite the coal or coke, so that only enough is used; any addition to this is wilful waste. For igniting coal, more wood will be required than for coke, and a little more time must be allowed for kindling a coal-stock. Whilst it is very important that the bed fuel be thoroughly ignited before the charging begins, it is not by any means a wise method to permit the stock to become white-hot before introducing the first charge of iron ; when once it is sure that the fire has spread evenly all through the fuel, and is about to strike through the top, the iron may then be charged. By this means the heat, which in the former case escapes uninterrupted up the stack, is utilized for raising the temperature of the iron charged before it has reached the melting-point, the result being quicker melting and hotter metal. See Cupola; Hood; Charging the Common Cupola. Lime. 238 Limestone- flux. Lime. — Lime is found in every part of the known world, the purest kinds being limestone, marble, and chalk. None of these substances however are lime, but are capa- ble of becoming so by burning in a white heat. Pure lime may also be obtained by dissolving oyster-shells in muriatic acid. See Limestone ; Marble ; Chalk ; Lime-kiln ; Flux; Oyster-shells. Lime-kiln. — An oven or a pit, built of brick, with an interior lining of fire-brick. Intermittent kilns are such as have the fuel on the bottom and the stone above it, making it necessary to withdraw every charge. Running kilns are usually in the form of an inverted cone, and are charged with alternate layers of fuel and stone, so that the lime is withdrawn at the bottom as it is burned, fresh fuel and stone being constantly served at the top. The process of burning expels the water and carbonic- acid gas from the stone, which falls to pieces on exposure to the air after removal from the kiln, and crumbles into a white flaky powder which is called quicklime, or slaked lime, and is possessed of highly caustic properties. See Limestone ; Lime. Limestone. — The name given to all rocks which are composed to a great extent of carbonate of lime. The chief varieties of limestone are chalk ; oolite, compact limestone of the hard, smooth, fine-grained rock, of a bluish-gray color; crystalline limestone; and statuary marble. Mag- nesian limestone or dolomite is a rock in which carbonate of magnesia is mixed with carbonate of lime. See Dolo- mite. Limestone-flux. — When the blast-furnace is in operation it is regularly fed with definite proportions of fuel, ore, and broken limestone. The latter is added as a Lining Ladles. 239 Liquid Bronze. flux to render the iron more fusible, and, by combining with the impurities in the ore, prevent the formation of compounds containing iron, thus effecting a saving of metal. See Oast Iron; Flux; Slag; Ore. Lining Ladles. — The process of daubing loam or ramming sand on the inner surface to protect them from the action of the molten metal. All ladles above 8 tons capacity should have a fire-brick lining all through ; below this, if the ladle bottom is per- forated to let out the steam, a fire-sand bottom, rammed over one inch in depth of fine cinders, will serve, one inch of daubing being sufficient for the sides. See Daubing ; Ingots ; Ladles. Lining-metal for Journal-boxes.— See Anti- friction Metals. Lining of the Cupola.— The inner structure of fire-bricks built within the shell of a cupola to protect it from the intense heat during the process of melting. See Oupola; Repairing the Cupola; Daubing; Fire-brick; Grouting. Lip is that part of a ladle-shell over which the metal falls as the process of pouring takes place. To regulate the stream of molten metal, and maintain it unbroken, is of great importance when numbers of various-sized basins must be served 'from one ladle ; a little experimenting will soon discover which form is the most suitable. See Ladles. Liquid. — See Fluid. Liquid Bronze. — See Stains for Metals. Liquid Fuel. 240 Loam. Liquid Fuel.— Liquid fuel, as petroleum, is used in a furnace specially constructed for the purpose. The oil is forced into the fire-box along with air or steam. Some have an injection placed above the fire-door, through which the liquid hydrocarbon is introduced. A cock regulates the supply, and at the mouth of the orifice superheated steam is associated with the petroleum at a temperature of 600° F. The hot ashes on the grate-bars receive the com- bined spray, and ignition takes place. See Fuel; Petko- leum. Litharge is the fused oxide of lead. See Eed-leap. Lixiviation. — The process of extracting alkaline salts from ashes by pouring water on them. Loadstone, or natural magnet, is a species of iron ore found in many parts of the earth. Its property of at- tracting small pieces of iron was known to the Greeks at an early date, and the Chinese have been acquainted with its wonderful directive power from very remote ages. When this wonderful ore has been carefully examined, it is found that some points possess greater magnetic force than others. The attractive points are the poles of the magnet, which, if rubbed in a particular manner on a hardened steel bar, its characteristic properties will be communicated to the bar, which will then attract filings like itself; particularly is this the case with the two ends of the bar. The bar is then said to be magnetized. For general purposes these bars are bent in the form of a horse- shoe, which admits of the two poles being brought into contact with the object to be lifted. See Magnet. Loaiii. — Foundry loam is a mixture of sand with clay and some form of venting medium. Refractory fire-sands suitable for loam are of themselves Loam-board. 241 Loam-board. too friable to form a compact, hard body. Clay is there- fore added to impart adhesiveness, with some accompany- ing substance, as manure, etc., to counteract its imporous quality, and leave the mixture when dry a hard, unyield- ing substance, that is permeated with countless small holes through which the surface gas finds its way to the exterior. The proportion of clay employed must be regulated by the class of castings the loam is for. The following mixtures are for ordinary use in almost any foundry, and any sands which approximate in their nature to the general run of Jersey, fire, and moulding sands will answer. If the castings are unusually light, as thin plate castings in loam, the clay-water should be pro- portionately thinner. Hand-made Loam for Loam-moulds and Core-barrels.— Fire-sand, 5 ; moulding-sand, 2 ; horse-manure, 1-J-. Mix with thick clay-water. Mill-made Loam for Loam-moulds and Core-barrels. — Fire-sand, 7 ; moulding-sand, 2 ; horse-manure, 2. Mix with thick clay-water, and grind no longer than is neces- sary to mix the ingredients intimately together. See HORSE-MANURE ; VESTING; FACING-SAND; LOAM-MILL. Loam-board is a technical term for any strickle, strike, sweep, or templet, so called, that may be employed for forming some part of a mould in loam; whether it be drawn along by the hands of a moulder horizontally, as for a pipe, attached to a centre-spindle to form circular moulds vertically, or be secured fast whilst the mould or core rotates past it, as for cores, both horizontal and vertical. Such boards should be bevelled on the edge, using the sharp edge for roughing up and the opposite way for skin- ning. See Sweep-board ; Roughing-tjp ; Strickle ; Loam, Loam-bricks. 242 Loam-mill. Loam-bricks are made in cast-iron moulds. The moulds being set on a smooth plate in the oven are filled with stiff loam and allowed to remain until dry. They are then useful for fashioning into cores with the saw and file, or may be used for building in parts where, on account of their rigidity, the ordinary bricks would interfere with the free contraction of the casting. The loam-bricks, being less rigid, yield readily to the pressure. See Loam. Loani-cake. — Flat cores, made by simply spreading loam of a stiff nature on a plate in the oven. They may be made any thickness desired, and strengthened by thrust- ing within the mass a few iron rods. These cakes make excellent covering cores. See Loam. Loam-mill is any contrivance for mixing well to- gether the ingredients of which loam is composed. The object is not so much to grind to a fine consistency as it is to thoroughly mix the clay and manure with the sand, so that every portion of the loam may be alike open in its na- ture. If the loam is ground too much by very heavy roll- ers, the clay becomes too intimately incorporated with the overground sand, the grains of which have been crushed into fine powder, resulting in a pasty mass which, when it yields its water, shrinks on the surface of the mould, leav- ing cavities and cracks which are difficult to correct, and always leave a map-like appearance on the casting. By retaining as much as possible the original coarseness of the ingredients the shrinkage spoken of is distributed equally throughout the surface, and is not noticed at all. Another evil which attends the use of all over-ground loam is, that, being less porous, the gases generated by the molten metal have greater difficulty in escaping in a legitimate manner, and hence force their way into the mould, creat- ing great commotion, and sometimes carrying off portions Loam-moulding. 243 Loam-patterns. of the mould surface, making scabs. See Loam ; Vent- ing. Loam ■ moulding. — Loam-moulding differs from sand-moulding in that the moulds proper are not contained in flasks, or bedded in the floor, but are constructed in sec- tions composed of rings, plates, and brickwork. Another chief difference is that sand-moulds are simply impressions of a model that is furnished by the pattern-maker, whilst loam-moulds are in some measure the handiwork of the moulder himself, unaided by the pattern-maker in many instances. There are instances where of necessity the operations necessary for the successful construction of a high-class loam-mould must include the three chief systems com- bined, viz., pattern, strickle, and spindle, with ample op- portunity throughout the task for supplementing these systems by a nicety of touch which may be acquired only by constant practice and close application by the most in- telligent moulders. See Touch ; Green-sand Mould- ing ; Dry-sand Moulding. Loam-patterns. — Numerous patterns may be readi- ly made from loam and much pattern lumber saved thereby; many, also, may be made quicker by this means, saving both time and lumber. Straight pieces of shafting, pipes, etc., may be struck on a barrel to the diameter required, after which a little water blacking will separate the thickness, which may be struck thereon after drying the core. Or should such a pattern be required more than once, the outside diameter can be struck at once, dried, coated with tar, and dried again. Such a substitute for the wood pattern acts very well in an emergency. If the pipe is a common socket, the bead and socket ends Lode. 244 Loosening-bar can be formed at once; but in the event of flanges they must be placed after the model is dry, as would be the case also if it were desired to affix a branch thereon. Bends of any description may be made from loam with either iron or wood templets and a former, each half being first struck on a core-iron to the core size, then dried, flanges fixed, and the thickness struck; first interposing a thin coat of water-blacking to separate the thickness from the core after the mould impression has been taken. The bottom half of such a pattern needs a few brads driven into the body, the heads of which, protruding some- what into the thickness, would prevent the thickness from falling off whilst it was doing duty for a pattern. A barrel core is thicknessed by wrapping a hay-rope on the core, and finishing off with clay and loam in the ordinary manner. Those unaccustomed to this method of producing a pattern will see by the above examples what the possibilities are when the emergency presents itself. See Former ; Tem- plet ; Core-barrel ; Thickness ; Loam. Lode. — The term used for an ore-producing vein. Ore occurs in either beds or mineral veins ; in the latter the veins are invariably found to have one of two or three principal directions, being either nearly parallel to the axis of elevation of the district, at right angles to that direction? or at an angle of 45° with it. The first are right-running lodes ; the second, cross-courses ; and the third, contra-lodes, or counters. See Ore ; Veins. Log. — A term of wide application in the foundry, mean- ing any piece of blocking-timber used for shoring purposes or as a bearing for flasks, etc. See Trestle. Loosening-lbar, or rapping-bar, is usually a round, pointed bar for jarring patterns previous to lifting off Low Moor Iron. 245 Lustre on Iron. the cope or drawing out a pattern. In the first instance the jarring effects a separation of the sand from the pattern before the parts are separated with the view of preventing a, bad lift; in the latter case the pattern is loosened and made to draw easier. Rapping-plates are, or should be, inserted in the pattern to receive the point of the bar, which is then struck in opposite directions with a hammer or sledge. See Rapping-plate ; Lift. Low Moor Iron. — This iron is manufactured under exceptional conditions, as both ore and fuel employed for making the pig iron used in their forges are of special quality, and are both obtained within their own premises. The ore is a brown ironstone, containing after calcination 42 per cent of metal, and is found in the coal-measures of the neighborhood. Even the limestone used for flux comes from the same county — Yorkshire, England. See Ores. Lug (or snug, in some localities) is an extension-piece cast on loam-plates for the purpose of handling and lifting by whatever method is in vogue. Some have staples of wrought iron cast in them to receive a hook, others again have simply a hole in the lug for that object but unless required for some special reason, a plain lug is amply suf- ficient when chains or slings are used for lifting with. See Snug; Pin and Cotter, Lustre is the brightness on the outer surface of a mineral, or in the interior when newly broken, as in pig iron, etc. When it can be seen plain at a distance, it is then termed splendent ; if weak, shining ; when the lustre is to be seen only at arm's length, glistening ; and glimmering when it must be held close to see the shining points. When the surface is without lustre- it is termed dull. Lustre on Iron. — See Iron-lustre. Mackenzie Slower. 246 Magnesium M. Mackenzie Blower. — The fan-blades in this blower are supported by a shaft, and caused to revolve by the revolutions of a cylinder contained in the shell. The fan- blades are loosely joined to the shaft and arranged so that they adapt themselves to a continuous alteration of the angle as they pass through the cylinder. Half-rolls in the cylinder act as guides for the fan-blades, allowing them to work smoothly in and out as the cylinder revolves. At each revolution the entire space back of the cylinder be- tween two blades is filled and emptied three times, that being the number of blades contained. See Blower. Mackenzie Cupola. — The Mackenzie cupola has a continuous tuyere, which allows the blast to enter the fuel at all points. Each size is proportioned to melt a given quantity of iron in a certain time. Above one ton per hour melting capacity they are made oval in form. This construction brings the blast to the centre of the furnace with the least possible resistance and, it is claimed, the smallest amount of power, causing a complete diffusion of air and a uniform temperature. The sizes of the cupolas indicate the melting capacity per hour; that is, a No. 1 melts 1 ton per hour ; No. 6, 6 tons ; and so on with all sizes. See Cupola ; Blower. Magnesium is a very brilliant metal of almost silvery whiteness. It is more brittle than silver at an ordinary temperature, but becomes malleable at something below a red heat. Its specific gravity is 1.74. It melts at a bright- red heat, and volatilizes at nearly the same temperature as zinc. In dry air its lustre is retained, but a crust of mag- nesia foi;ms on its surface when subjected to a moist air. Magnesian Limestone. 247 Malachite. Magnesium in the form of a wire or ribbon takes fire at a red heat, burning with a dazzling bluish-white light. The pure oxide of magnesium (magnesia) is obtained by ignit- ing the carbonate, but this is both a difficult and expensive means of obtaining it, and recourse is had to the impure magnesian limestones found in Thuringia and in some parts of England. It is a white powder, varying in density according to the source from whence it is obtained. It is unalterable by heat, and has never been fused; and on ac- count of its refractoriness is valuable as an ingredient for the manufacture of crucibles for metallurgical purposes. See Dolomite. Magnesian Limestone.— See Magnesium. Magnet. — There are two kinds of magnets — natural and artificial. The natural magnet is an iron ore which has the property of attracting to itself particles of iron or steel. If suspended, it takes a north and south direction, and it is from this particular leading property that it is called leadstone or loadstone. The magnet {magnes in Greek) is supposed to have received its name from Magne- sia, in Asia Minor, where iu was first discovered. See Loadstone. Magnetite is a magnetic iron ore, or oxidulated iron. It is one of the richest and most important ores of iron, and produces the finest brands of steel. It is found in al- most all parts of the world, and occurs crystallized in iron in black octahedrons and dodecahedrons; also massive, as well as in the form of sand. See Okes. Malachite. — A mineral, the green carbonate of cop- per ; also called velvet cojiper ore. It is much admired as an ornamental stone for inlaying purposes. There are two Malleability. 248 Malleable Cast Iron. varieties, the fibrous and the compact. Constituents : cop- per 58. carbonic acid 18.0, oxygen 12.5, water 11.5. See Copper; Minerals; Metals. Malleability. — A property possessed by metals which renders them capable of being beaten out with a hammer or pressed into plates between rollers. Gold surpasses all metals in malleability, being capable of reduction into films not exceeding the 200,000th of an inch in thickness, whilst iron has been rolled into sheets less than the 2500th of an inch in thickness. The malleability of metals is here given in their respective order of value, beginning with the highest : Gold, silver, copper, tiu, cadmium, platinum, lead, zinc, iron, nickel, palladium. See Ductility ; Metals ; Strength of Materials. Malleable Bronze. — Hard bronze may be made malleable by the addition of from \ to 2 per cent mercury, which may be combined with either of the metals compos- ing the mixture before the bronze is finally made. It can be put into the melted copper at the same time the tin is added, or can be used as an amalgam with the tin. See Bronze; Alloys; Brass. Malleable Cast Iron is made by a process of de- carburizing the articles made from cast or pig iron in the annealing furnace, where they are subjected to an oxidiz- ing atmosphere somewhat below the fusing-point. The furnaces employed for this purpose consist of iron plates to enclose the necessary space, which serve also as guides for the doors, which are raised perpendicularly, being bal- anced by a weight at the back of the furnace. The inside of the furnace consists of fire-space and the oven proper, an arch extending over both, the fire-space being separated from the oven by a bridge wall extending nearly to the Malleable Iron. 249 Malleable Iron. arch, leaving only a narrow space through which the flame is forced by the blast, completely filling the oven. The gases escape through small outlets in the corners to the flues below, which are fitted with a damper operating from the front. The castings to be rendered malleable are placed in cast iron covered boxes or saggers, along with oxide of iron, and subjected to a red heat in these furnaces for from two to six days, according to the magnitude of the castings. They are then allowed to cool slowly. See Decarbonize. Malleable Iron. — By depriving cast iron of a por- tion of its carbon it may be converted into malleable or wrought iron, becoming ductile and tenacious, and capable of being hammered or rolled into thin sheets or drawn into fine wire. Malleable or wrought iron has a fibrous texture, but if it is subjected to repeated jarring or blows it be- comes again brittle, and can only be restored by heating and reworking. The ordinary processes of converting cast iron into malleable are : refining, puddling, shingling, hammering, and rolling. The refining-furnace consists of a flat hearth covered with sand, around which are metal troughs through which a constant stream of water is kept running, to prevent the sides from melting; tuyeres set in the direction of the hearth connect with the blowing-en- gine. The cast iron is melted with coke on the hearth, and a blast of air which blows directly over it causes the carbon of the iron to unite with the oxygen of the incom- ing air and pass away as carbonic-oxide gas. Oxygen also unites with the silicon present to form silica, and with the iron to form the oxide. A slag of silicate of iron is also produced by the silica of the sand uniting with the oxide of iron. When the molten mass has been sufficiently re- fined it is run out on cast-iron plates, which are kept cool by streams of water. This process only partially decarbon- izes the iron; it is then broken into pieces and passed to Mallet. £50 Manganese. the puddling-furnace, where it is again melted and brought up to a high temperature, when it is subjected to the ac- tion of a current of air, by which means the carbon burns to carbonic acid, a portion of the iron is oxidized, and this oxide unites with the silicon in the iron and forms a fusi- ble slag. The workmen by means of long bars keep up a constant stirring or puddling of the mass, so that the whole may be exposed to the air, and to intimately mix the oxide with the metal. After a time the iron loses its fluid- ity, blue flames appear on the surface, it becomes pasty, and finally falls to pieces. The fire is now quickened, and the loose masses unite. They are then gathered by the puddler into balls, which are at once conveyed to the squeezer, or shingling hammer, where the slag is pressed out and the metal formed into a bloom, which is at once passed through the rough ing-rolls, and finally the finishing- rolls, which in some instances completes the operation. The quality of the iron is improved by taking the bars from the roughing-rolls and cutting them into lengths, to be reheated in piles or fagots, and then rolled or hammered out together. See Puddled Steel. Mallet. — A wooden hammer for service in the foundry, where the marks produced by the smaller iron-faced ham- mer is objectionable. Besides the ordinary wood mallets, with heads 3^- inches long, 2 inches diameter at the ends, there are now made for the trade raw-hide mallets from 1 inch to 2f inches diameter at the head; they are made entirely of hide, except the handle, and are especially valuable where light thin castings are made, as they are not as likely to damage the patterns. Manganese is one of the heavy metals, of which iron may be taken as the representative. Its color is grayish white, of high metallic brilliancy, it takes a fine polish, is Manganese bronze. 25l Manganese-copper. non-magnetic, fuses at a white heat only, and is so hard that steel and glass may be scratched by it. As spiegel- eisen, or white iron, it contains 8 to 15 per cent of man- ganese. Ferro-manganese, another regular article of com- merce, contains from 25 to 75 per cent of manganese. These alloys of manganese, with carbon and iron, along with certain small proportions of other elements, consti- tuting either spiegeleisen or ferro-manganese, according to the percentage of manganese contained in the alloy, are in- dispensable for the manufacture of steel by the Siemens, the Bessemer, or the crucible modes of procedure. Manganese combines with carbon and silica, forming un- important compounds. One of its principal uses is chemi- cal, under the form of an oxide ; it is employed in this state for decomposing hydrochloric acid, in the manufacture of chlorine, as a cheap source of oxygen, and as coloring material in the manufacture of glass and enamels. See Spiegeleisen ; Ferro-manganese ; Steel. Manganese-bronze.— This bronze, manufactured by P. M. Parsons, England, for everypurpose for which gun- metal has heretofore been employed, and for which object it constitutes an eminently superior alloy, is made by adding from 1 to 2 per cent manganese to the common bronzes of copper, tin, and zinc. It is largely used for propeller-blades, sheathing, bearings, piston-rings, etc., and is said to be 60 per cent stronger than gun- metal, and will wear three times as long. See Bronze ; Brass. Manganese-copper is used as a strengthener to bronze and brass. The density, ductility, and tensile strength of the metal is increased, as it prevents the for- mation of copper and tin oxides. The alloy is made from copper 70, manganese 30, of which composition sufficient Manheim Gold. 252 Marsh-gas. must be used to bring the mixture up to the required de- gree of hardness. A very hard bronze is made by using from 3 to 6 per cent. A suitable mixture for bearings would be copper 80, tin 6%, zinc 4J, manganese-copper 9. A hardness resembling steel is produced by increased quantities of cupro-manganese, or manganese-copper. See Copper ; Bronze ; Brass. Manheim Gold. — A brass imitation of gold, com- posed of copper 16, zinc 4, and tin 1. To insure close re- semblance to gold, the crucible must be clean, metals pure, and it is best to melt under powdered charcoal in a covered crucible. See Gold ; Tombac. Manure.— See Loam ; Horse-manure. Marble is a rock belonging to the varieties of carbon- ate of lime which have a granular and crystalline texture. It is composed of carbonate of lime, either almost pure when the color is white, or combined with oxide of iron or other impurities which give various colors to it. The far- famed quarries of Carrara, Italy, have supplied this beauti- ful material for statuary purposes from time immemorial. The pure white marble is quarried also in Vermont, but it is not held in as high estimation as that from Italy. Of variegated marble there are many sorts found in this country, but generally not fit for sculpture. See Lime- stone. Marble-chips. — The chips from a marble-yard are the very best material to use as a limestone-flux in cupolas, being comparatively free from the deleterious substances usually found in the commoner kinds of limestone. See Flux ; Limestone-flux. Marsh-gas, usually called fire-damp by miners, is Martin Steel. 253 Match part. often abundantly disengaged in coal-mines from apertures or "blowers/' which emit for a length of time a copious stream or jet of gas, probably existing in a state of com- pression pent up in the coal. When the mud at the bottom of pools in which water-plants grow is stirred it suffers bubbles of gas to escape, which if collected are found to be a mixture of marsh-gas and carbonic anhydride; and it is thought by some that these two gases represent the principal forms in which the hydrogen and the oxygen re- spectively were separated from wood during the process of its conversion into coal. See Air ; Venting. Martin Steel is made in the reverberatory furnace by adding malleable iron to the molten pig iron after the latter has been melted. See Steel. Match-board. — Same as match-plate, except that it is made of wood instead of metal. See Match-plate ; Match-part. Match-part, sometimes called a "sand odd-part" by the moulder. This is a device for economizing time in making partings when a large number of castings are re- quired to be made in the same kind of flasks. One method of procedure is as follows : Procure a well-made " roll-over " board, and arrange the pattern or patterns suitably for gating, etc., and wherever portions of the pattern must of necessity project upwards into the cope, set them just in that position on the board by cutting out the wood at the points of projection, taking care that the parts of the board adjacent to the patterns shall leave the parting all ready made around them when the nowel has been rammed and rolled over. Another ready way of accomplishing this is to extemporize a match-part by forming the same in sand, hard rammed into an odd flask of equal dimensions with Match plate. 254 Meadow-ore. the ones to be used; this may be coated with tar and dried, and will be found very serviceable. A decided improvement on the last may be obtained by first making the parting in the usual manner and covering the same with oil, and a good sprinkling of parting-sand; after which set thereon a wood frame (no deeper than is absolutely necessary), having a bottom nailed on, with a few nails driven here and there clear of the parting. A hole in the centre will per- mit the space to be filled with plaster, which, running all over the surface and around the nails, will, when set, be found a perfect impression of the joint required. The nails will prevent it from dropping out. See Match- plate; Koll-over Board. Match-plate. — A plate provided with pin-holes cor- responding to pins and holes of the top and bottom flasks between which it is placed, to be rammed on both sides be- fore it is removed, and thus save the labor of making a joint or parting. Should the patterns present one plain side, allowing all the mould to be contained in the nowel, all such may be secured to the lower side of the plate ; but in the event of there being a portion in each flask, then the patterns must be cut and each part secured to the match- plate exactly opposite to each other on either side of the match-plate. See Match-part ; Sand Odd-part. Maul. — A heavy wooden sledge-hammer, useful in the foundry for many purposes for which iron ones are objec- tionable. They are especially effective for settling down iron copes on a sand-joint, bedding-in large patterns, or any purpose where a steel-faced hammer would be likely to break or mar the surface struck. Meadow-ore. — Conchoiclal bog-iron ore. See Bog- iron Ore, Measurement of Castings, 2oo Melting point. Measurement of Castings. — See Weights of Castings. Medals. — If it is desired to obtain a convex and a con- cave plaster-mould from a medal, press tin-foil close into every part of the surface and pour on the requisite thick- ness of plaster, after which, when it has hardened, take off the medal and oil the tin-foil surface, over which the pias- ter is again poured. When the latter thickness of plaster has hardened, they may be separated and the foil taken off. Should the medal have under-cut parts which interfere with a direct separation, then use glue instead of plaster, and the moulds may be forcibly withdrawn without ma- terially damaging them. Any other flat object may be treated as above described. See Glue-moulds. Melting a Small Quantity of Iron. — See FONDERIE A CALABASSE. Melting-furnace. — The cupola and reverberatory are the iron-foundry melting-furnaces; the crucible air- furnace, forced-draught, and reverberatory are the brass- founders' and steel-melters\ A reverberatory furnace is employed by glass-makers for calcining the materials, and crucible or "glass furnaces" to melt the glass. The appli- cation of the Siemens regenerative process is becoming general for all these purposes, excepting for iron-foundries, and a considerable saving in fuel is effected wherever this system obtains. See Furhac^s. Melting-point. — Tho exact amount of heat at which metals and other substances become fused and lose their identity. (See Fusibility.) The following gives the melting-points of the simple metals mentioned, but the melting-points of alloys are invariably below those of the Mending-up. 256 Mercury or Quicksilver. simple metals composing them. (See Fusible Alloys.) Oast iron melts at 3477 degrees; wrought iron, 3981; steel, 2501; gold, 2587; silver, 1250; copper, 2550; tin, 420; zinc, 741; brass, 1897; lead, 617; aluminum, and 700 degrees. Mending-up. — The art of repairing broken surfaces in the mould, which may have been caused by accident, carelessness, or faulty models or patterns. This phase of the moulder's art calls for the nicest manipulation, with delicate fashioning-tools made for the purpose. See Finishing. Mercury or Quicksilver.— A metal always fluid in our climate, but solidified by intense cold into a malle- able metal resembling silver. It is found native as well as combined with sulphur, when it is called cinnabar. But cinnabar is easily reduced at a red heat to the metal- lic state by the action of iron or lime, or atmospheric oxygen ; the sulphur being extracted, when iron is used, as sulphide of iron; when lime is used, as sulphide and sul- phate of calcium ; and as sulphurous-acid gas when oxygen is used. The alchemists of old did not believe mercury to be a true metal, because they were unaware of its suscepti- bility to freezing into a compact solid. With the exception of iron and platinum, mercury will readily unite with all metals into an amalgam. (See Amal- gam ; Amalgamation.) Liquid amalgams of the precious metals are largely used for gilding and silvering objects which have been made in baser metals. The amalgam is spread over the object with brushes, after which the mer- cury is driven off by the application of heat, leaving a film of the nobler metal firmly adhering to the object treated. Mercury has a great affinity for all other metals that are soluble in mercury; for if an object be dipped into it there is great difficulty in rubbing off the mercury, which im- Metallurgy. 257 Metals. mediately adheres to it- If mercury is rubbed over tin-foil, it unites in one mass and forms an amalgam, as is the case with mercury and lead. When lead and bismuth are mixed with mercury, the amalgam will be equally fluid with the mercury itself. This important metal is used for barometers, thermometers, silvering looking-glasses, and for many other useful purposes, including the making of ver- milion. It is largely employed in separating the precious metals from extraneous matter. Mercury is the heaviest of all metals except gold and platinum; consequently silver, iron, lead, etc., float upon it as wood does upon water. The production of mercury (1882) in Austria was 542 tons; Italy, 55 tons; Spain, 929 tons; United States (principally Almaden, Cal.), 2054 tons. See Tin; Amalgam; Fluid Alloy; Metals. Metallurgy. — In a limited sense metallurgy includes only the operations attendant on the separation of metals from their ores; but it really comprehends the whole art of working metals, from the mining of the ore to the produc- tion of the manufactured article. See Metals; Minekals; Obes; Reduction of Metals. Metals. — There are three states in which metals occur in nature. First, some of them, as gold, silver, platinum, and mercury, are frequently found uncombined. These are said to occur in their native state. Second, many are obtained alloyed with each other, as gold and silver with mercury; but invariably they are found in combination with the metalloids, for which they have a strong attrac- tion; these constitute the third state, and are known as metallic ores. The metals are conductors of electricity and heat, but differ in this respect. Some metals are so volatile that they may be distilled from their compounds. Mercury boils at 662°; lead is volatilized to some extent, Metals, 258 Metals, and in a slight degree copper also, in the smelting-furnaces; and gold will dissipate in vapor in the focus of a powerful burning-glass. With regard to their fusibility metals show a marked difference. Mercury remains fluid at 39°; so- dium and potassium fuse below the boiling-point of water; silver and gold melt at a red heat, iron at a white heat; and platinum only yields to the action of the oxyhydrogen blowpipe. There are great differences with respect to specific gravity of metals. While platinum is twent} T -two times heavier than water, lithium is only about half as heavy as that liquid. The lightest metals have the strong- est affinity for oxygen. Some of the metals are neither malleable nor ductile, yet others again have those proper- ties to a remarkable extent. Gold may be hammered to the 200,000th of an inch in thickness, and wire has been drawn from platinum to the 30,000th of an inch in diameter. The metals exhibit wide differences in hardness. Steel may be tempered to scratch glass, while potassium is as soft as wax. To pulverize gold or copper great force is required ; yet others again, notably antimony and bismuth, may be re- duced to powder in a mortar. The following table gives the relative properties of various metals, their names being arranged in a descending series : Power to Power to conduct Brittleness. Malleability. Tenacity. Ductility. conduct Electricity. Heat. Silver Antimony Gold Iron Gold Silver Copper Arsenic Silver Copper Silver Copper Gold Bismuth Copper Platinum Platinum Gold Zinc Cerium Tin Silver Iron Tin Iron Chromium Cadmium Gold Copper Iron Tin Cobalt Platiuum Zinc Zinc Lead Lead Columbium Lead Tin Tin Bismuth Antimony Manganese Zinc Lead Lead Bismuth Titanium Iron Nickel Tungsten Nickel Cadmium Meteoric Iron. 259 Metre Meteoric Iron. — Iron mixed with nickel, as found in meteoric stones or aerolites. See Meteoric Stones ; Iron; Nickel. Meteoric Steel. — Steel resembling the famed Da- mascus steel is made by melting in a plumbago crucible, well covered with charcoal, silver 4, nickel 16, zinc 80, and pouring the alloy into water, which renders it friable. It may then be readily crushed to pow T der, and added to steel as follows : Blister-steel, 28 pounds; chromate of iron, 8 ounces; quicklime, 2 ounces; porcelain clay, 3 ounces; meteor- powder, 10 ounces; melted in the regular way, cast into an ingot, drawn into bars, and in every respect treated like any other cast steel. If the surface is washed with dilute nitric acid (acid 1, water 19), the wavy surface common to Damascus steel will be more pronounced. See Steel; Damascus Steel. Meteoric Stones. — Usually called aerolites, fire- balls, or shooting-stars, which occasionally fall from the atmosphere. When taken up soon after their fall they are found to be hot; and, no matter where they descend, they are all similar in composition, being composed of silica, mag- nesia, sulphur, iron in the metallic state, nickel, and some traces of chromium; their specific gravity varies from 3.352 to 4.281, that of water being taken as 1.000 or unity. Their exterior appears as if blackened in a furnace but the in- terior appears of a grayish white. Their size varies from a few ounces up, one in the Museum of Natural Sciences, Philadelphia, weighing 800 pounds. See Meteoric Iron. Metre. — A measure of length equal to 39.370 English inches, or 39.368 American inches, the standard of linear measure, intended to be the ten-millionth part of the dis- tance from the Equator to the North Pole, as ascertained Metric System. 260 Mill-cinder. by actual measurement of au arc of the meridian. See Metric System. Metric System. — The metric system of weights and measures was first adopted in France, and by Act of Con- gress was authorized to be used in this country 1866. It is a decimal system, and the nnits of length, superficies, solidity, and weight are all correlated, two data only being used — the metre, and the weight of a cube of water the side of which is the hundredth part of a metre. Upon the metre are based the following primary units: the square metre, the arc, the cubic metre or stere, the litre, and the gram. The square metre is the unit of measure for small surfaces. The arc is the unit of land measure, and is a square whose side is 10 metres in 1, or 100 square metres. The cubic metre or stere is the unit of volume, and is a cube whose edge is one metre in 1. The litre is the unit of capacity; this is the capacity of a cube whose edge is - f V °f a metre in 1. The gram is the unit of weight, and is the weight of distilled water contained in a cube whose edge is the T ^ ¥ part of a metre. From these primary units the higher and lower orders of units are derived decimally. See Metre. Mica. — A mineral of a somewhat metallic lustre, that will permit of being split in thin plates, which can be substituted for glass in ship's lanterns, etc.; also for mounting transparencies in stoves. It is a widely diffused and plentiful mineral, entering largely into the composition of granite, mica-slate, etc. It consists essentially of silicate of alumina, with which are combined small portions of sili- cates of potash, soda, oxide of iron, oxide of manganese, etc. See G-rakite. Mill-cinder. — The slag produced at the reheating and Milled Lead. 261 Minerals. puddling furnaces. This slag, after several days' roasting, becomes highly refractory, and is known as bulldog, mak- ing an excellent substance for the bottoms of puddling- furnaces. These rich slags are sometimes mixed with the ores in the blast-furnace, and the iron thus produced is then denominated cinder-pig ; but, owing to the large percentage of phosphorus usually present in pig iron made by this method, it is very inferior in quality. These slags are frequently called tap and forge cinder. See Slag. Milled Lead.— Sheet lead made in the rolling-mill by passing the metal through the rolls. See Sheet Lead. Mill-furnace. — A furnace employed to reheat the puddled bar after it has become too cold to pass through the rolls to a finish. Mill-rolls.— See Eolls. Mineral Cotton.— If a jet of steam is forced through liquid slag, the latter is changed into a mass of fine white threads, which when gathered together appear like cotton wool. It is sometimes called mineral wool. If an extra strong current of moist air be blown into a cupola that is slagging freely, this phenomenon is likely to occur. Mineralogy. — The science which treats of the solid and inanimate materials of which our globe consists, the four classes of which are earthy minerals, composing the greater part of the earth's crust ; saline minerals, inflam- mable minerals, and metallic minerals. See Minerals; Metals; Earths. Mineral Oils.— See Petroleum. Minerals are all such natural bodies as are destitute Mirrors. 262 Mixing Cast Iron. of organization, existing either within or on the surface of the earth, and which are neither animal nor vegetable. The hardness of minerals, beginning with the softest, is as follows: 1. Talc; 2. G-ypsum; 3. Calcareous spar; 4. Fluor- spar; 5. Apatite; 6. Feldspar; 7. Quartz; 8. Topaz; 9. Sapphire; 10. Corundum; 11. Diamond. See Precious Stones; Earths; Minerals. Mirrors. — For methods pursued in producing glass mirrors, see Mercury. For metal mirrors, see Brass Mirrors. Mitis Metal. — The name given to an alloy of alumi- num with wrought iron. For the production of castings in this metal, t*he wrought iron is heated until it has be- come pasty, and then treated to a small quantity of alumi- num, which immediately liquefies the iron in a fit condition for pouring into the moulds. These so-called mitis castings, it is claimed, have all the properties, excepting fibre, that wrought iron possesses, be- sides being much softer than cast iron. Wrought-iron or mild-steel scrap is usually the basis of this metal ; but no matter what the kind of material be, it is preferable that it should not contain more than 0.1 per cent of phosphorus when the best results attainable are desired. About 3^ ounces of aluminum are sufficient for 100 pounds of iron. See Aluminum. Mixing Alloys.— See Alloy. Mixing Cast Iron. — The art of mixing certain pro- portions of different brands of iron to obtain castings of such quality as will best serve the purpose for which they are intended. Without a chemical knowledge of the act- ual ingredients needed for the production of a certain qual- Mock Gold. £63 Modelling. ity of iron, mixing cast iron must always remain in the realm of conjecture. True, there is much to be said in favor of the superior facilities for subsequent testing ; but this gives no substantial data, and must always be repeated on every change of the materials employed. Late develop- ments relating to the power of silicon to change the nature of cast iron has opened a way for a more intelligent system of mixing. See Analysis ; Testing-machine; Silicon; SOETENEES J GRADES OE PlG lEON. Mock Gold. — See Gold Alloy; Ormolu. Mock Platinum. — A factitious platinum is pro- duced by mixing 5 zinc with 8 brass. For composition of brass, see Brass. Mock Silver is a white-metal alloy, ordinarily used by jewellers, etc. If 3.53 of silver be alloyed with 11.71 copper and 2.4 of platinum, the composition will have about the same specific gravity as the pure metal. Pack- fong, or tutenag, another imitation, is composed of : cop- per 40.4, zinc 25.4, and nickel 31.6. German tutania : tin 48, antimony 4, copper 1. See Silver Alloys ; Imi- tation Silver. Modelling. — The art of designing or copying works of art in clay, for the purpose of obtaining moulds in which they may be cast in plaster or metal. The fingers, aided by a few implements of metal or wood, — usually both, — are the only tools required for fashioning the clay. Or- dinarily, the common potters'-clay will serve this purpose : but for designs which occupy a lengthened period to pro- duce, it is mixed with other ingredients to keep it in a moist condition. The support of a figure in modelling is of great importance, requiring in some instances a skele- Modellers' Wax. 264 Molasses. ton of wood or iron supports on which to work the clay. When the model is complete, a plaster impression of the same is taken in sections, which are then placed to- gether in precisely the same position as they occupied on the model; the space originally occupied hy the model is now filled with plaster, and when the cast is well set the mould is carefully taken off, exposing a finished cast of the model. This is a much better plan than that of the ancient sculptors, who simply dried the clay model ; but clay cracks and shrinks in drying, therefore plaster-casts from the models are best. See Founding of Statues ; MODELLING-CLAY. Modellers' Wax.— See Wax. Modelling-clay. — Common potters'-clay mixed with water will answer for inferior work ; for work of superior quality dry clay may be brought to the right consistency with glycerine; but for models requiring considerable time for their completion, and to avoid the repeated moistening to which they must be subjected, it is best to use a clay composed of : clay 3, sulphur 6, oxide of zinc 1, fatty acids 2, fats 10. First saponify the zinc-white with oleic acid, which then mix with the other fatty acids ; add sul- phur in flowers, and the clay in dry powder. See Oils ; Zinc; Pottery. Moire Metallique. — A crystalline appearance of great beauty given to tin-plate by brushing over the heated metal a mixture of 2 parts of nitric acid, 2 of hydrochloric acid, and 4 of water. As soon as the crystals appear the plate is quickly washed, dried, and varnished. See Tin. Molasses. — A brown, viscid, uncrystallized syrup produced in the manufacture of sugar. Owing principally Molecule. 265 Molecule. to the gluey nature of this product, it can be made of great use in the foundry. Core-sands void of the quality of adhesiveness may, by beiug mixed with molasses, be made sufficiently tenacious to admit of their being employed where, if sands containing aluminous substances were used, there would be great difficulty in extracting the core when cast. The molasses, owing to its sticky nature, holds the loose grains of silica together until the molten metal has solidified, during which time all its cohesive qualities have been burned away by the intense heat, leaving the sand free to run out of the cavity at the slightest provocation. Common beach and river sands may be made serviceable by the use of molasses when the cores are for light castings; but when it is desired to accomplish similar results in heavy castings, the more refractory silica sands must be used. Molasses is now extensively used for mixing with the sil- ica sands, etc., used in steel casting, in order to bring these incoherent materials up to the right consistency for form- ing the moulds. Mixed with water until the latter may be pronounced very sweet, it is an excellent restorative for a badly burned mould surface, especially when a little black lead has been stirred in. If the mixture be too thick with molasses, in- stead of penetrating the burned mould surface, it will lie there and form a hard skin, which, as it dries, separates and curls up, bringing the sand with it, and making mat- ters worse. See Cobe-sand ; Floub ; Glue ; Steel Castings. Molecule. — One of the constituent particles of bodies. The molecules of bodies are divided into integrant and constituent, the integrant having properties similar to the mass, and are consequently simple or compound, as the mass is either one or the other. A mass of pure metal consists of integrant particles, each of which has metallic Mosaic Gold. %66 Moulding. properties similar to those possessed by the whole mass. Similarly, a mass of alloy consists of integrant particles, each of which is a compound of the different metals form- ing the alloy. When a compound integrant molecule is decomposed we arrive at the constituent molecules. There- fore oxygen and hydrogen are the constituent molecules of an integrant molecule of water. Mosaic Gold. — A cheap brass used for making imi- tation jewelry. It is made by alloying copper with about equal parts of zinc. See Gold Alloy; Ormolu; Tombac. Mottled Iron. — The variety of pig iron which is evidently between the two extremes of white and gray. The fracture shows a decided mottle, seemingly caused by the distribution of detached portions of white iron through- out a matrix of gray iron. Pig iron is termed high or low mottle, according to the proportion of white iron present in the pig. See Gray Iron; White Iron"; Oast Iron". Moulding. — The art of preparing moulds from plastic materials of such a nature as will successfully resist the in- tense heat of molten metal, — as loam or sand, — in which may be formed the object to be produced in metal, the process being completed when the metal has been melted, run into the mould, and solidified. True, there are moulds used for special purposes in iron-casting other than those composed of sand; as for instance, rolls, car-wheels, etc., which require to be chilled in parts. This is accomplished by providing smooth cast-iron surfaces for the metal to lie against. Again, castings in zinc, lead, tin, or alloys made from these metals are frequently cast in moulds composed entirely of either brass or iron ; by this means the castings are not only a true duplicate of each other, but are made much cheaper. Moulding in Dry Sand. 267 Moulding-machines. For flexible moulds, see Glue-moulds and Elastic Moulds; also, "The Iron Founder" and "The Iron Founder Supplement," in which works the whole art of moulding is comprehensively set forth. Moulding in Dry Sand. — See Dry-sand Mould- ing. Moulding in Loam.— See Loam-moulding. Moulding-machi lies. —These machines, in infinite variety, are now recognized everywhere as competent to pro- duce castings of limited variety, in a far superior manner than is possible by the old methods. Besides the numerous excellent gear-moulding machines of Scott, Whittaker, Buckley & Taylor, and Simpson, — which, with a small por- tion of the pattern corresponding to the gear to be moulded, are all able to produce gears from 9 inches diameter up, either spur, bevel, mitre, mortise, or worm, plain or shrouded, — we have numbers of machines for the produc- tion of general work of all descriptions. Some of these machines are still worked with hand-levers, but these are being rapidly superseded by steam, hydraulic, and pneu- matic contrivances, which, with their several automatic arrangements, demonstrate the capacity of their builders to overcome difficulties which until very lately seemed beyond the bounds of possibility. The "Tabor" moulding-machine may be used with either steam, water, or compressed air; but steam is prefer- able in most cases, because it can be easily obtained with- out the use of special auxiliary machinery of any kind. The rammer system of this machine gives greater pressure at parts which would otherwise be too soft. The "Yielding Platen" moulding-machine is provided on the top with a rubber bag containing water or com- Moulding-sand. £68 Muck-bar. pressed air, and the bottom of the machine is caused to rise by compressed air, thus forcing the flask with its sand against the rubber bag, which, they claim, presses the sand in a manner impossible by any other known method. The " Teetor " moulding-machine provides means for holding the flask securely and turning it over ; also for jarring the pattern and holding the same perfectly level, to allow a clean separation of the mould therefrom. Moulding-sand.— See Facing-sand. Moulding-tools. — Broadly speaking, moulding-tools consist of every foundry equipment necessary to make moulds with, including shovel, brushes, riddles, clamps, wedges, parallels, level, compass, vent-rods, gaggers, ram- mers, etc.; but the more artistic class, used for finishing the moulds with, are the ones usually recognized as mould- ing-tools. A full description of these, with instructions for using them, will be found at their respective places throughout this work. Moulds for Steel.— See Steel Castings; Ingot- moulds. Moulds, Open-sand.— See Open-sand Moulding. Moulds, Pressure in.— See Pressure in Moulds. Mousing-hook. — A hook with some contrivance for preventing the hook, ring, or link resting therein from slip- ping out. Muck-bar. — When the iron has been balled in the puddling-furnace, forced through the squeezer, and passed once through the roughing-rolls, it is termed muok-bar, Muffle. 269 Nails. and is ready for being cut into pieces for piling, reheat- ing, and rolling again. See Rolling-mill. Muffle. — An arched vessel with a flat bottom, made of refractory materials, in which to place cupels and tests in the operations of assaying, to preserve them from coming- in direct contact with the fuel. One end is open, and slits on the side allow a draught of air through it. The sub- stances operated upon are by this means effectually shielded from the impurities of the fuel. See Assay. Muiitz-metal. — An alloy of copper and zinc used for the sheathing of ships, composed of copper 60, zinc 40. This alloy admits of hot rolling. See Brass ; Copper; Sheathikg-metal. Musliet Cast Steel is made by melting malleable scrap-iron with charcoal and oxide of manganese in cruci- bles directly, independent of blister-steel. See Steel. Mushet's Crucibles.— See Crucibles. Music-metal. — Tin 65.8, antimony 8, copper 26, iron 3.2. The common alloy is tin 80, copper 20. See Brass; Copper; Alloys. N. Nails. — Formerly all nails were made by hand or forged on the anvil, and large quantities are still produced in this manner in England and other parts of Europe. Nail-mak- ing by machinery was originated in Massachusetts in 1810. At present we have machine wrought-nails, cut-nails, and cast-nails. The machine cut-nails are simply wedge-like in breadth, equal in thickness — head and body — to the sheet Naphtha. 270 Natural Gas. iron from which they are cut, and these are always to be preferred for strengthening and securing the sand surfaces of moulds, rather than those which have had heads forged on them. The length of iron machine cut-nails and the number contained in a pound will be found in the follow- ing table : Length No. Length No. Length No. Size. in in a Size. in in a Size. in in a inches. pound. inches. pound. inches. pound. 3-Penny. li 420 6-Penny. 2 175 12-Penny. 3J 52 4 " 1* 270 8 " 2i 100 20 " 3* 28 5 " If 220 10 " 3 65 30 " 40 " 4 4* 24 20 Naphtha. — This word is derived from the Persian (to exude), and was originally applied to an inflammable liquid hydro-carbon which exudes from the soil in certain parts of Persia. The term is, however, now used to desig- nate a similar and almost identical fluid that issues from the ground in many parts of the world, and is known as petroleum, rock-oil, etc., but the term is also applied to other liquids which resemble true naphtha in little else than in their volatility and inflammability, as methylic alcohol or wood-spirit, etc. See Petkoleum. Native Iron. — Native iron is of rare occurrence ; it almost always forms part of meteoric stones. When found it is malleable, and may be worked like manufactured iron. See Meteokic Irok. Natural Gas. — Gas-springs or gas-wells through which issue combustible gases from the earth are to be found in various parts of the world. It was by this means that the holy fires of Baku, on the Caspian, and the sacred fires of the Greeks were supplied with fuel. It is supposed to be the same as the fire-damp of coal-mines, which is New Red sandstone. 271 Nickel. liberated by the pick of the miner. In all cases these com- bustible gases consist to a large extent of marsh-gas, also called light carbu retted hydrogen. (See Marsh-gas.) In many cities throughout the States, notably Pittsburg, the gas is used altogether as a steam-producer; for heating metals, — iron, steel, brass, etc., — in the diverse branches of their utilization, except for smelting ore, in which coke con- tinues still to be employed. Natural gas has an intense heat- ing-power, is free from substances deleterious to metals, is cheap and easily handled, and leaves no ashes. One thou- sand cubic feet of gas is equivalent in heating-power to 56 pounds of coal, which represents a saving of 20 per cent at first cost, besides the labor of handling and transportation. See Fuel. New Red-sandstone. — The name given to a group of sandstones, generally of a red color, occurring between the carboniferous rocks and the lias, which name is given them in contradiction to the old red-sandstone group, which lies below the coal-measures and has a similar mineral structure. See Old Red Sandstone; Facing-sand; Black Sand. New Sand. — Fresh sand from the quarries and pits, furnished to the foundries for moulding purposes. See Black Sand; Facing-sand; Old Sand. Newton's Fusible Metal.— Bismuth 8, lead 5, tin 3. This alloy melts at 212°. See Fusible Alloys. Nickel. — A white metal which, when pure, is both ductile and malleable. Its color is intermediate between that of silver and tin, and is not altered by the air. It is nearly as hard as iron. Its specific gravity is 8.27, and when forged 8.66. The species of nickel ores are its alloy Nickel plating. 272 Nitre. with arsenic and a little sulphur and its oxide; the first is the most abundant, and the one from which nickel is usually extracted. It is known to mineralogists by the German name of kiipfer nickel, or false copper, from its color and appearance. Nickel only occurs in the native state in meteoric stones. Nickel fuses at 2800° F. Its ores are found in the United States and in Germany, Sweden, and Hungary. The effect of the magnet upon pure nickel is very little inferior to that which it exerts on iron, but this entirely ceases when the metal is heated to 350° F. The chief use of nickel has been in the composition of various alloys, especially German-silver, all of which are duly noticed in their respective order. It is, however, be- ing gradually introduced as an alloy with steel for ship's armor, etc. See German -silver. Nickel-plating. — The art of nickel electro-plating was invented by Bottcher about 1848, and had developed into an important industry. The best kind of solution to use is one of the double sulphate of nickel and ammonia, which should be saturated at 25°, and used in conjunction with a plate of nickel as positive electrode. See Plating. Niello-engraving. — A kind of engraving of consid- erable antiquity. It was very much practised in the middle ages. The art consisted in drawing a design with a stylus or needle on gold and silver plates, and then cutting it with a graver. These incised lines were then filled with a composition of copper 1, bismuth 1, lead 1, and silver 9, the compound being of a bluish color when a little sulphur is added. The metal is called Niello-silver, or Tula. Nitre, or Saltpetre, as it is commonly called, occurs as a native product in the earth in many parts of the Nitric Acid. 273 Nitric Acid. world, and is separated therefrom by leaching the soil and allowing the nitre to crystallize. It is artificially formed by heaping up organic matter with lime, ashes, and soil, and keeping the mass moistened with urine for a lengthened period, when the heap is lixiviated and the salt crystallized out. Nitre dissolves in about three times its weight of cold and one third its weight of boiling water. Paper dipped in this solution and dried forms what is known as touch-paper. Nitre has a cooling, saline taste, and strong- antiseptic powers. Owing to the latter quality it is exten- sively used in packing meat. It is chiefly consumed, how- ever, in the manufacture of gunpowder ; the large amount of oxygen it contains, and the feeble affinity by which it is held, adapting it for sudden and rapid combustion. Nitric Acid. — The two principal constituent parts of our atmosphere — oxygen and nitrogen gases — when in cer- tain proportions are capable under particular circumstances of combining chemically into one of the most powerful acids — the nitric. For all practical purposes, nitric acid is obtained from nitrate of potash, from which it is expelled by sulphuric acid. The nitric acid is of considerable use in the arts. It is employed for etching on copper ; as a solvent of tin to form with that metal a mordant for some of the finest dyes; in metallurgy and assaying, in various chemical pro- cesses, on account of the facility with which it parts with oxygen and dissolves metals. For the purposes of the arts it is commonly used in a diluted state and adulterated with sulphuric and muriatic acids, by the name of aqua- fortis. Two kinds are made : one called double aqua- fortis, which is one half the strength of nitric acid ; the other simply aquafortis, which is half the strength of the double. A compound made by mixing two parts of the nitric acid with one of muriatic, known formerly by the Nitrogen. 274 Numbering Pig Iron. name of aqua regia, and now by that of nitro-muriatic acid, has the property of dissolving gold and platina. On mixing the two acids heat is given out, an effervescence takes place, and the mixture acquires an orange color. See Aqua Regia; Atmosphere. Nitrogen.— A gas discovered by Rutherford in 1772. It is extensively diffused in nature, forming about four fifths of the atmosphere, in which it plays the important part of diluting the oxygen and adapting it to the condi- tions of life. It is an important element of the vegetable kingdom, entering in considerable quantity into many of its compounds. It is supplied to plants by ammonia and nitric acid. Our food is largely composed of nitrogen, and it forms 16 per cent of the tissues of the animal body. Nitrogen is not found in any of the mineral formations of the earth's crust, except in some varieties of coal. See Atmosphere; Oxygen; Ammonia. Nosing. — The projecting moulding on the edge of a stair tread, which stands immediately in front at the top edge of the riser. Nowel. — The bottom flask in a set composed of cope and nowel. See Flasks. Numbering Pig Iron. — The numbers given to pig iron, as No. 1, No. 2, No. 3, etc., is singly a commercial classification in order to distinguish the various qualities as delivered from the blast-furnaces, indicating to the pur- chaser the grade or quality of each brand and the purposes for which they are best adapted. No. 1 invariably shows the largest crystals, is soft and bright, and adapted for light castings; No. 2, of the same brand, will be recognized as lighter in color, with smaller crystals, suitable for general Number g Gold. 275 Oils and Fats. work, machinery, etc. ; while again, of the same brand we may have a more dense iron, with indications of mottle, which is denominated No. 3 ; and so on to white iron, a higher number still. See Oast Iron, White Ikon, Gray Iron, Mottled Iron. Number of Nails in a Pound. — See Nails. Nuriiberg' Gold. — A mock gold, exactly like Man- heim. See Manheim Gold. Nuts in Loam-plates. — When it is desired to connect one or more plates (with the intervening bricks), in loam-moulding, where staples for hook-bolts would be objectionable, a reliable substitute for the latter will be found by casting threaded nuts at parts of the plate con- venient for inserting iron bolts with threads on both ends. The nuts can be made immovable in the plate by filing a slight V at the corners for the molten iron to fill when the plates are cast. See Binding-plates. Oils and Fats. — Fats are merely solid or semi-fluid oils. The fixed oils and fats form a well-defined group of organic compounds, which are abundantly obtained from the animal and vegetable kingdoms. They are not so heavy as water, their specific gravity ranging from 0.91 to 0.94. They differ very much in their degrees of solidity, and do not consist of any single substance in a state of purity, being principally mixtures in varying proportions of four different but closely-allied bodies, viz. : stearine (or suet); palmitine (so called from olive-oil, being very abundant in the latter); margarine (from a pearl, owing Oils and Fats. 276 Oils and Fats. to its pearly lustre) ; and oleine. The three first are solid at common temperatures, while the fourth remaius liquid. Fat is softer and its melting-point lower in proportion to the quantity of oleine it contains. Fats are all soluble in ether, oil of turpentine, benzol, and to a certain extent in alcohol, but not in water. The most solid fat sare readily reducible, and become reduced to a fluid or oily state at a temperature lower than that of the boiling-point of water. When the fats or oils are boiled with an alkali they undergo the remarkable change called saponification. The fat by this process is decom- posed into a fatty acid and glycerine, the acid combining with the alkali to form soap, and the glycerine passes into solution. Chevreul discovered that the fats and oils consisted of several proximate principles, known as stearine, margarine, and oleine, which are each capable of being separated into an acid and a base, the base being the same in all, and known as glycerine. Oleine is that portion of oil which, as before said, causes its fluidity. Stearine gives to certain fats and oils the opposite quality of solidity, as in candles, etc. Margarine resembles stearine in its property of hardness; it exists in human fat, butter, olive-oil, etc. The fixed oils are of two classes — the drying oils, or those which harden on exposure to the air; and the unctuous oils, or those which remain soft and greasy under the same exposure. The hardening of the oils is due to the absorp- tion of oxygen. The most important of the drying oils is linseed, which is obtained by subjecting flaxseeds to pressure. Next in importance as a drying oil for paints is hemp-seed, poppy, and walnut. The most important non-drying oils are olive-oil, almond-oil, and colza-oil, which are extensively used in making soap, candles, and illuminating oils. Casi Oil-stone. 277 Opal. tor-oil is a connecting link to these two classes of oils, being gradually hardened by long exposure to the atmosphere. The drying property of oils is much increased by heating them with about .05 of their weight of litharge, which becomes dissolved by the oil. Linseed-oil thus treated is known as boiled oil. See Litharge. Oil-stone.— See Whetstone. Old Red-sandstone.— This group of sandstone lies below the carboniferous strata, and was called " old " to distinguish it from a series N of similar strata which occur above the coal-measures. See New Red- sandstone. Old Sand.— See Black Sand; New Sand; Facing- sand. Oleine.— See Oils. Olive Bronze Dip for Brass.— Nitric acid 3 ounces, muriatic acid 2 ounces; add titanium or palladium. When the metal is dissolved add two gallons of pure soft water to each pint of the solution. See Stains eor Met- als. Onyx. — A chalcedony, with alternate layers of white, black, and brown. It is found in Saxony, Arabia, and Ireland, and is used largely for cameos. See Peecious Stones. Oolite. — A variety of limestone, so called from its being composed of small rounded grains resembling the roe of a fish, cemented together by a calcareous formation. See Limestone. Opal. — A species of the quartz family of minerals, from Open-hearth Cast Steel. 278 Open-hearth Cast Steel, which it differs in containing 5 to 13 per cent of water. It is a precious stone, consisting principally of silica with some alumina. When first dug from the earth it is soft, but it hardens and diminishes in bulk by exposure to the air. The specific gravity varies from 1.9 to 2.5. Sub- species of this gem are called the semi and the wood opal. It is translucent, usually blue or yellowish white, and ex- hibits a beautiful play of brilliant colors owing to minute fissures which refract the light. Found in Hungary, Queenstown, and the United States. See Minerals ; Precious Stokes. Open-hearth Cast Steel.— This steel is produced on a large scale and is so called to distinguish it from steel made by the Bessemer process, by puddling, or from blister- steel melted in the crucible. Heath, in 1845, patented his invention of producing cast steel by dissolving malleable scrap in molten cast iron by a process independent of crucibles, by melting pig iron in a cupola, and running this into the bed of a steel-making furnace, into the upper part of which the malleable iron was introduced in bars, that they might be heated by the waste heat and gradually pushed forward so as to dissolve in the molten pig, with the formation of steel. Siemens said this method would have been successful had the re- generative principle been known to Heath, whereby he could have obtained the requisite intensity of heat and absence of cutting draught essential to the proper combi- nation together, by fusion, of the wrought and carbonized iron without oxidation. Substantially, with the addition of the use of a regenerative furnace and improved working details, it is one of the forms of steel-making now known as the Siemens or Siemens-Martin processes. By employ- ing the open-hearth and steel-melting regenerative furnace in the processes of steel-making, the highest possible tern- Open-sand Moulding. 279 Open-sand Moulding. peratures are attainable, and the evil effects of a cutting flame and strong draught are obviated. The Siemens or ore process of producing steel consists in melting hematite or other pig iron free from sulphur and phosphorus, and then adding in small quantities at a time an equally pure ore until a sample, taken out from time to time, does not harden on plunging into water while red-hot. To the fused iron spiegeleisen, etc., is then added. Another method consists of a combination of the Martin and the ore process ; the pig and scrap, etc., being fused together, and the decarbonization being then effected, not through oxidation by the gases alone, but by that together with ore added to the mass. The Pernot furnace for steel-making is simply a Siemens-Martin furnace with a rotating bed, the hearth being a saucer-shaped cavity supported by an iron frame, mounted on a nearly vertical axis, and running on wheels upon a rail or guide, supported on a stout bogie. The bed is rotated by means of gear- wheels. The charges of pig iron and scrap are well heated before being placed on the hearth, which, when it is made to revolve at from 2 to 4 revolutions per minute, causes the different pieces to keep constantly changing their position; and this, coupled with the fact that one half of the bed is being alternately brought under the full action of the flame as the charge slips down at each revolution, brings about a very rapid fusion of the mass. See Kegenerative Fur- nace. Open-sand Moulding. — The process of moulding castings that have one plain side, in the sand floor of the foundry. Even for such castings it is usual to cover them with a cope, which, when secured, permits of pressure being applied to force the metal close to the upper surface, so that the casting has nearly the same appearance all over; but when the metal is poured into an open mould it must as- Ordnance 280 Ordnance. sume a horizontal position of its own accord. If, when the open mould has been cast, fine dry sand is scattered evenly over the surface of molten iron to the depth of one-fourth of an inch, it will shield the metal from the action of the atmosphere and thus prevent the formation of blisters, which almost always rise when the surface is left unpro- tected. When the mass has solidified more sand may be added with the shovel, in such quantity and location as will favor equal cooling of the whole. See Bed. Ordnance signifies, in its most comprehensive sense, every kind of artillery, including guns, mortars, howitzers, etc. Many of the early pieces of ordnance were made of hooped bars. The mortar, which was introduced about the commencement of the fourteenth century, was the first European firearm. About the beginning of the fifteenth century bronze cannon were cast, and it is probable that cast-iron cannon of small calibre were made during the sixteenth century. However, there is positive evidence of iron cannon being cast about 1740 by English workmen, who were afterwards taken across the Channel to teach French- men the art. Cannon-founding has therefore been practised nearly five hundred years; but it would appear, from the wonder- ful specimens in steel and wrought iron lately produced by Armstrong, Whitworth, Krupp, and some others, that the art of casting ordnance was doomed to decay, as even the monster 300-pounder rifled Parrott and the 15-inch 450-pounder Rodman appear almost insignificant when compared with the more modern steel monsters constructed by the above-named inventors. Bronze and cast-iron cannon are cast in loam or sand in moulds prepared in the customary manner. They are cast vertically, with an addition to the length to make up for shrinkage, and also to carry off the snllage. It was for- Oreide. 281 Oreide. merly the practice to cast them hollow ; since then, how- ever, solid ones have occasionally been preferred. But the results were not satisfactory, and the Kodman principle has been extensively adopted, the idea being to cool the metal in layers from the inside outwards, thus modifying the initial strain upon the gun, and producing the best results that may be expected from cast iron for ordnance purposes. The method is to flow cold water through the core-barrel dur- ing the process of casting and for a stated time afterwards, according to the thickness of the casting. The manner of constructing the mould is as follows : The mould is a dry- sand one, contained in circular sectional casings of length sufficient for the casting with its sinking head. The chief feature is the core-barrel, which consists of a sound, water- tight cast pipe or barrel, with flutes on its exterior surface along its whole length, to permit the gas to escape upwards from behind the hemp and loam with which the barrel is coated. After the mould has been closed together the bar- rel is attached to a spicier or tripod, the legs of which rest upon the top flange of the casing ; adjustable screws at the ends of each leg admit of a ready adjustment of the core after it has been suspended and lowered into its place in the mould. The water for cooling is led to the bottom of the core-barrel by a pipe which stands central in the space; it then ascends through the annular space between the pipe and the barrel, and flows off by a suitable arrange- ment at the top. For a 15-inch gun treated this way the barrel may be withdrawn in about twenty hours, after which a continuous flow of cold air is forced through the bore until the casting is cool enough to be removed, which in this case is about nine or ten days. See Spider ; Uore- BARREL ; DRY-SAND MOULDING. Oreide. — An alloy supposed to be of French origin; it is used as a substitute for "ormolu" in the manufacture dres. 282 'Orea. of cheap jewelry, excelling the latter alloy very much in its gold-like character. First, melt copper 100, then add and stir well in magnesia 6, sal-ammoniac 3.6, quicklime 9.12, tartar of commerce 9, and zinc or tin 17, in the order as given. This must be kept fusing about three quarters of an hour before it is used. Copper 80, zinc 13.5, nickel 6.5 is recommended as equal to the former as an oreide mixture. See Ormolu; Mosaic Gold; Mock Gold; Gold; Tombac. Ores are the mineral bodies from which metals are extracted, the latter being found therein sometimes in a metallic state, and so nearly pure as to be called native metals. But it is generally in a state of ore that metal occurs, that is, in combination with its mineralizing sub- stance. When metals combine in the metallic state they are termed alloys; combined with acids, they form carbon- ates, bromides, phosphates, chlorides, etc., and are then designated metallic salts. With sulphur they form sul- phurets and sulphides; and, again, combined with oxygen they form the numerous oxides. The soil and rocks consist of metallic oxides, but the chief metals are not so widely disseminated. They are found in various places and at different depths below the surface, in the form of seams, beds, or mineral veins, and sometimes as lodes (See Lode). The treatment of ores for obtaining the metal is mechanical and chemical, the more valuable ores requiring considerable care in their manage- ment; but the operations vary considerably, according to the kind of ore under treatment. The ores of lead and tin when brought to the surface are at once sorted, and the purest lumps set aside for treat- ment in the smelting-furnace ; what is left, after being subjected to a crushing or hammering process, is again Ores. 283 Ormuio. sorted. What remains is then crushed in revolving cylin- ders and passes through sieves, the finer residue being agi- tated in water by a process termed jigging. The crushing is completed in the stamping-mill, where the ore is repeat- edly pounded and washed, and the powdered ores settle in layers, according to their specific gravity. The chemical treatment of ores is invariably twofold — roasting or calcining, and reducing. (See Calcination".) If they contain volatile products, as sulphur and arsenic, which may be removed by oxidation or heat, they are first roasted. This is accomplished in a kind of reverberatory furnace, where the fuel is served at one end and the flame and heated gases are reverberated or thrown down from the arched roof of the furnace upon the ore, which is distributed over its bed. In this way ores are oxidized. Should the ore contain sulphur, it is burned off and passes away as sulphurous acid, while arsenic escapes in the form of arsenious acid. Sometimes lead is at once procured by the operation of roasting, or it is changed to the state of oxide, which necessitates another process to set it free. Reduction of ores means the chemical process of deoxid- ation, or smelting. It is effected by heating them to a high temperature in contact with substances which take the oxygen from the metal by superior affinity. Carbon is the chief among deoxidizing agents, and removes the oxygen in the form of carbonic oxide and carbonic acid. For the removal of the numerous earthy impurities, sub- stances are employed which are called fluxes ; these readily combine with them in a molten condition and flow off as a slag. See Cast Iron ; Reduction of Ores. Organ-pipes are usually made from a composition of tin 9, lead 1, subject to slight variations. See Alloys; White Alloys; Tin; Lead. Ormolu. — A variety of brass having a near resem- Ormolu Dipping Acid. 284 Ounce. blance to gold, containing from 25 to 50 of zinc to 50 of copper, according to the tint desired. To successfully fuse this alloy, let the zinc be added to the fused copper at the lowest temperature possible, gradually introducing the zinc until the whole amount has been added. In many cases it is used for the ornamentation of furniture. A gold lacquer is sometimes used to heighten the color of the alloy, but the native color of the metal may be preserved if properly brought out by means of sulphuric acid, then washing in water, and applying a liquor varnish to keep it from tarnishing. See Brass; Dipping; Stains for Metals; Oreide. Ormolu Dipping Acid for Sheet Brass.— Sulphuric acid 2 gallons, nitric acid 1 pint, muriatic acid 1 pint, water 1 pint, nitre 12 pounds. Put in the muriatic acid last, a little at a time, and stir with a stick. For cast brass: Sulphuric acid 1 quart, nitre 1 quart, water 1 quart; a little muriatic acid may be added or omitted. See Dip- ping. Ormolu ed Brass Dipping Acid.— Sulphuric acid 1 gallon, nitric acid 1 gallon. This is a quick bright dipping acid for brass-work that has been already or- molued. See Dipping. Osmium. — This metal was discovered by Tennant in 1803. It belongs to the class usually termed " noble," and occurs in association with platinum in the form of an alloy with iridium. It is the least fusible of all the metals, as the oxyhydrogen jet will volatilize, but not fuse it. This metal, like iridium, is extensively employed for tipping gold pens. See Metals. Ounce.— A division of the pound weight in English. Ovens for Drying Moulds. 285 Ovens for Drying Moulds. In Troy weight it means the twelfth part of a pound, and weighs 480 grains. In avoirdupois weight the ounce is the sixteenth part of a pound, and equal to 437J grains Troy. Ovens for Drying* Moulds and Cores.— Much subsequent annoyance and loss is saved by exercising forethought with regard to location, size, and style of oven when it has been decided to build a new or make extensive alterations in an old foundry. Some moulds, owing to their magnitude and form, must necessarily be built in the casting-pit and dried there. The pit becomes, in such cases, a drying stove or oven by simply closing the mouth and building open fires at convenient places on the bottom if wood or bituminous coal is used for fuel; if anthra- cite coal must be the fuel, then recourse must be had to extemporized exterior fireplaces, with suitable arrange- ments for creating a draught. It is, however, possible, in -some instances, to build large moulds in sections, and by this means convey all the parts to the oven to be dried — a very superior way when it can be done. Temporary contrivances for drying small cores are to be met with in almost every foundry, from the rim and bottom-plate of the heating stove to the more elaborate device consisting of wrought- or cast-iron sides bolted together, inside of which are slides to rest shelves upon, the top having a hole with raised edge to receive a stove-pipe. The hinged door may be the full size of the oven, so as to expose all parts of the oven at once. An ordinary fire-pot, with provision for draught underneath, can be set down in the floor and this oven set over it, or the plates may be long enough to permit the fireplace to be enclosed within the structure, and thus make the oven a portable one. Millet's patent core-oven for small cores is a brick struc- ture with an iron front, to which is attached the Necessary hinges for swinging the perforated shelves in and out. Ovens for Drying Moulds. 286 Ovens for Drying Moulds. Each of the shelves works independently, and, by means of a duplicate door on the back, the oven is closed, thus retaining the heat in the oven while the cores are being loaded or unloaded. It will be seen that no heat escapes. Gores may be handled with dispatch, as all operations are conducted outside, so that both fuel and time are econo- mized. Other excellent ovens for small cores may be obtained from the supply dealers at a very low cost, which when placed down on the floor and a pipe connection made are at- once ready for use. Steam-heated ovens are now very numerous. They con- sist of steam-piping laid direct from the boiler to the oven, where a valve controls the amount of steam allowed to enter a system of coils, which latter constitute the core shelves as well, being set somewhat slanting for drainage. Sixty pounds steam-pressure in the coils give a tempera- ture in the oven of 250°, which is sufficient to dry ordinary cores without the possibility of burning them; an increased pressure will, of course, give greater heat. Ventilation is perhaps best secured by a somewhat loose-fitting door and an outlet at the bottom of the wall. The ordinary ovens for drying large moulds and cores are, as a rule, very defective, lacking in suitable rack aud carriage accommo- dation, — two very important features, well worthy of more than ordinary consideration. To save the annoyance and loss attendant on moving heavy loads in and out of the oven, they may very readily be constructed of two main walls of masonry, having hinge fixings built in them on the top and ends, to which plate-iron doors may be accu- rately hinged. When the moulds are ready for the oven, the covers are thrown back and the end or ends opened, so that a free passage is made for loading direct from the crane to the oven, and thus obviating the jarring of the moulds which usually attends transit on carriages. Clos- ing over the top covers and shutting in the ends converts Overhead Cranes. 287 Oxide, Carbonic. this into an admirable oven at once, which, when the moulds are dry, may be opened again and become, as it were, part of the foundry floor, on which the moulds may rest safely until required for closing and casting. For description and details of special large oven constructed by the author, see " The Iron Founder," p. 52. See also Damper; Rotary Ovens. Overhead Cranes. — See Cranes ; Iron-carrier. Oxalic Acid. — This substance exists as binoxalate of potash in common sorrel and the rhubarb plant, which accounts for the acid taste common to those vegetables. As oxalate of soda it is found in the barilla plant, and as oxalate of lime in lichens. It is commonly prepared by the oxidation of sugar or starch with nitric acid : 1 part of sugar is dissolved in 8 parts of nitric acid and gently heated, when intense action ensues, with a copious disen- gagement of nitrous-acid fumes. The crystals obtained are sour and poisonous, resembling Epsom salts, for which they are often mistaken. Chalk or magnesia suspended in water acts as an antidote in cases of poisoning. This acid is extensively used in calico-printing, and is also employed as a test for the presence of lime. It also removes ink and iron stains from cloth by forming a soluble oxalate of iron, but the fabric suffers injury if the acid be not washed off immediately. Oxidation. — The process or converting metals or other substances into oxides, by combining with them a certain portion of oxygen. It differs from acidification in the addition of oxygen not being sufficient to form an acid with the substance oxidized. See Oxides; Oxygen. Oxide, Carbonic. — When a mixture of purified charcoal and oxide of iron or zinc is exposed to a strong Oxides. 288 Oxygen, heat in an iron retort, the metallic oxide is gradually re- duced, and during the. reduction a great quantity of gas is evolved. This gas is a mixture of carbonic-acid gas and another gas, which burns with a blue flame and is called carbonic oxide. See Gas; Oxygen. Oxides.— Substances combined with oxygen without being in a state of acid. The metallic oxides are the most important, and occur naturally as abundant and valuable ores. See Metals ; Ores ; Reduction or Okes ; OXY- GEN. Oxidized Metal is silver or other metal subjected to a process of dipping into a boiling solution of hyposul- phite of soda or ammonium sulphide, continuing the pro- cess until the required degree of discoloration has taken place. It may then be varnished with non-transparent varnish consisting of alcohol 18, red arsenic 3, castor- oil 1. See Dipping; Lacquering; Staining Metals. Oxygen. — This gas was obtained by Dr. Priestley in 1774 from red oxide of mercury exposed to a burning lens, and again in the following year by the Swedish chemist Scheele. With regard to the importance of this great dis- covery Prof. Liebig observes : " Since the discovery of oxy- gen the civilized world has undergone a revolution in man- ners and customs. The knowledge of the composition of the atmosphere, of the solid crust of the earth, of water, and of their influence upon the life of plants and animals, was linked with that discovery. The successful pursuit of innumerable trades and manufactures, the profitable sepa- ration of metals from their ores, also stand in the closest connection therewith. It may well be said that the material prosperity of empires has increased manifold since the time oxygen became known, and the fortune of every individual Oxyhydrogen Blowpipe. 289 Oyster shells. has been augmented in proportion." Eight ninths of water consist of oxygen; it forms one fifth of air and about one half of silica, chalk, and alumina, which three constitute the chief substances of the earth's surface. It is abso- lutely essential for the support of animal life. In mechan- ical combination with nitrogen it forms the atmosphere surrounding the globe, and is given off by all growing plants when under the influence of sunlight. Its chemical affinities for other elementary substances are very powerful, combin- ing with all except fluorine. Owing to the intensity with which many of these combinations takes place, this gas has the power of supporting combustion in an eminent degree. It is tasteless, colorless, inodorous, and has hitherto resisted all attempts to liquify it. Combustion is nothing more than a chemical union of the oxygen of the air with the combustible body or some of its elements. We make the fire hotter by bringing more air in contact with the fuel. See Combustion; Flame, etc. Oxyhydrogen Blowpipe.— An apparatus for burning oxygen and hydrogen together to produce very high temperature. Now extensively used for melting plati- num and other metals. The oxygen and hydrogen pass through separate tubes and mix at the mouth of the jet, producing the most intense heat known. Oyster-shells. — The carbonate of lime being the prevalent component of the oyster-shell, it has on that ac- count been substituted for limestone as a flux in the cupola at many foundries. But shells are not as effective for this purpose as good limestone, owing to the adhering impu- rities, which invariably contain some phosphorus. See Shells; Limestone Flux ; Flux; Phosphorus. Packfong. 290 Pan. P. Packfong. — An alloy much used by the Chinese, and by them called " white copper," consists of copper 40.4, nickel 31.6, zinc 25.4, iron 2.6. See Gekman-silver ; White Alloys. Packing Sand. — The process of forcing sand into the flasks or around patterns bedded in the floor is some- times termed packing. See Bamming. Palladium. — This metal closely resembles platinum in color and appearance ; it is also very malleable and ductile. It is not so dense as platinum, being only 11.8, and it is more easily oxidized than that metal, but cannot be melted at ordinary temperatures. Palladium readily alloys with other metals. When alloyed with silver it is very suitable for the graduations on mathematical instruments, etc. It is used also as a galvanizing agent for protecting other metals when amalgamated with mercury, the iron or other articles being cleansed previously as for zinking. See Metals; Zlnking. Pan, or Kettle, is usually a wide, shallow, round or spherical - shaped vessel, of cast-iron or other metal, em- ployed in the manufacture of sugar, salt chemicals, soap, tin-plate, and in the various processes connected with metallurgy. For sugar-refining there are evaporating-pans, vacuum-pans, condensing-kettles, vats, coolers, etc. Salt- pans are usually very wide and shallow, and are set in rows over a furnace. The brine is pumped into them, the heat evaporates the water, and the salt precipitates. The chem- ical works employ large numbers of pans of different shapes, heavy and light, such as the flat furnace-pans, 8 to 10 feet Paper-moulding. 291 Paper-moulding. across, which are sometimes over 6 inches thick at the crown; lighter ones, as crystallizing cones, etc., are used in large numbers. Pans for soap-making are termed " boilers," and consist of a deep, circular, tapered pan with a spherical bottom. Brackets cast on the sides serve to set the pan on standards over the fire. Pans used for tin-plate are of cast iron. They are set in a row, and are named, respectively, the tin-pot, wash-pot, grease-pot, pan, and list-pot. Pans for metallurgical purposes are termed amalgamators, being usually an open, flat-bottomed, pan in which the pulverized ore and mercury are ground together between slabs of stone or metal. (See Amalgamation.) Owing to the great de- mand for castings of this class, much ingenuity has been practised for moulding them readily, resulting in well- established methods of production, which far excel the ordinary systems of moulding. See Kettle; Casing. Paper-moulding 1 consists of grinding old paper along with other materials into a pulp, which by the aid of presses and other machinery is moulded into the required form, dried, and then subjected to the processes of sizing, decorating, etc. It is used extensively in the production of architectural ornaments, etc., being less brittle than plaster for that purpose. By mixing white of egg, sul- phate of iron, glue, or quicklime, etc., with the pulp it is partly made waterproof, and to make it almost fireproof it only requires a further admixture of borax and sulphate of soda. Another method of producing articles in paper is to glue sheets of paper together and then subject the whole to powerful pressure in dies accurately fashioned to the form of article to be made. This operation is performed when the sheets are moist, which admits of the requisite curvature and flexure without damage to the article, which when dry becomes as hard as board, and is then ready to Paper-parting. 292 Parallel Straight-edges. be operated upon by the japanners, inlayers, and other artists in ornamentation. Paper-parting. — Ordinary monlding-sand will not adhere to paper that is free from substances of a gummy or gluey nature, no matter how hard it has been rammed thereon. For this reason it makes an excellent substitute for parting-sand at parts of a joint where it is difficult to apply the sand in either a wet or dry condition. See Part- ing; Joint; Partikg-sand. Paper Sheathing for Studs.— It is sometimes convenient to use a plain stem chaplet at parts of a casting where there is not sufficient body of metal to partially fuse, and thus fasten it. In such a case the surrounding cast iron is chilled, and it is with great difficulty that a thread can be made by which to insert a plug. If, before the chaplet is inserted in the mould, a thick layer of paper be glued thereon and an extra coat of silver-lead applied, the hole will be clean and the metal soft for tapping. Paraffine is a product of the distillation of wood (es- pecially beech-wood), coal, and petroleum. It is a white, hard, inodorous, tasteless, crystalline solid, resembling sper- maceti. It melts at 111°, and is formed into candles, which burn with a very bright name. It is a pure hydrocarbon. Paraffine- oil is the term given to the thin oily matter given off during the process of distillation. See Petro- leum. Parallel Straight-edges are two straight strips of wood or metal, of equal widths along their length. By setting them edge up, some distance apart, on a pattern or mould, and allowing the eye to range along the upper edges of both, any deviation from a true and even surface is soon Paris Gold. 293 Parting-sand. discovered, the eye being very quick to detect any dis- crepancy. See Level; Bed. Paris Gold. — A cheap imitation of the pure metal. See Oreide; Tombac. Parisian White Metal is composed of copper 69.8, zinc 5.5, cadmium 4.7, nickel 19.8. See White Alloys. Part. — A foundry term, used to signify any one of the sections composing a set of flasks ; as top-part, middle- part, bottom-part, etc. See Flasks. Particle. — A minute part of matter, an assemblage of general atoms, of which natural bodies are composed, as a particle of sand, etc. Parting. — The joint or point of separation in moulds composed of two or more sections. A suitably prepared surface at some portion of a mould that will permit one part to be separated from another without fracturing the sand structure. For a separation of plain moulds con- tained in a cope and nowel, the sand-joint is made smooth and sprinkled all over with dry parting-sand, which pre- vents any portion of the sand rammed over it in the cope from adhering thereto. But should any portion of such joint assume a vertical or other form than the horizontal, the parting-sand must be moistened before it will adhere to the joint surface; especially is this the case with draw- backs, which separate in a vertical position. In either of the latter-mentioned cases paper maybe substituted for the moistened parting-sand. See Drawbacks; Paper-part- ing ; Parting- sand. Parting-sand is sand specially adapted to the pre- vention of joint, or separating surfaces amalgamating when Paste. 294 Paste Gems. they have "been rammed against each other. Beach and river sands are eminently adapted for this purpose, as all clayey compounds have, by the action of the water, been washed out. New fine free sand, well burnt to eliminate every trace of clay, is adapted for use as a parting-sand; and it may be said that the beach and river sands have their parting qualities enhanced by burning, the burnt cores from the castings being always preferred to the new sands. See Parting ; Joint ; etc. Paste. — Foundry-paste is simply flour mixed with water to a consistency suitable for the joining together of dry-sand cores and moulds that are made in sections. It may also be used in the coring of moulds when it is desir- able to effectually prevent the escape of metal at the points of junction, its spreading quality permitting the soft, yield- ing mass to be forced into every crevice, where, if the mould be hot enough, it dries into a hard impenetrable mass. There is much danger, however, in using too much paste, especially in cold moulds. When the molten metal enters the mould the wet surfaces are at once converted into steam, which, if not all ejected during the process of cast- ing, seldom fails in producing blow-holes at some part or other. See Size; Blister; Blow-holes. Paste Gems are a glass imitation of precious stones, made from a combination of silica, potash, borax, red oxide of lead, with some arsenic. This is fused gently in Hessian crucibles, in the furnace, for about twenty- four hours, and it then becomes a base for the manufacture of all the spu- rious gems. For the ruby, 72 parts of oxide of manganese are mixed with 2880 parts of the paste; emerald — green oxide of copper 42, and oxide of chrome 2, to paste 4608 parts — sapphire: oxide of cobalt 68, to paste 4608 parts; fused for thirty hours. Amethyst — oxide of manganese Patent Fluxes. 295 Patent Fluxes. 36, oxide of cobalt 24, purple of cassius 1, to paste 4608. The tints of the real stone are so exactly imitated in many of these imitations as to deceive any but the best judges. See Precious Stones. Patent Fluxes. — In addition to the limestone, fluor- spar, and other fluxes, used in the cupola, blast-furnaces, puddling-furnace, smelting and refining, steel, and copper and brass works, there are numerous other compounds, etc., which are protected by letters-patent, by the use of which it is claimed that steel can be welded to steel or iron, with the best results; preventing the metal from burning by flowing easily, and enveloping it so as to exclude the air. For cupola-melting it is claimed they will save fuel, im- prove iron, make clean cupolas, and other improvements too numerous to mention. Mr. Kirk, author of " Founding of Metals," is the inven- tor of a flux for the cupola, and in presenting his compound says as follows: "It will make hard iron soft, will reduce the percentage of iron lost in melting, will cleanse iron of impurities, will flux the cupola, and make a brittle slag. In introducing this compound as a cupola-flux, we intro- duce an entirely different theory of fluxing from that used in a blast-furnace, or that formerly used in the cupola, for we propose to flux the iron entirely with the gases gener- ated by the compound, and not with the slag formed by it. The chemicals which we use in the compound are very rich in carbon, and when distributed over the fuel and heated by it they generate a very strong carbonic gas in the cupola, and this gas is absorbed by the iron from the time it begins to heat until it is drawn out of the cupola ; so that we have a great deal more time to operate upon it than any of the mineral fluxes do, yet we do not have time enough to change an iron from one extreme to the other, Pattern. 296 Pattern and can only improve it to a certain extent at one melting; but by continued re-melting with the compound we can change the hardest of iron to the softest. If any founder doubts this theory of fluxing and improving iron by the gases, he has only to throw sufficient brimstone into his cupola on the fuel to form a sulphuric gas in the cupola, and he will find his iron to be as hard as glass; and if iron can be hardened by one gas, it can be softened by another." See Flux; Cupola; Slag. Pattern. — In moulding, the pattern is a counterpart of the casting required, from which the moulder obtains an impression in sand or other plastic substance. This im- pression obtained, it remains to fill the space, previously occupied by the pattern, with molten metal, which when solidified is a true representation in metal of the pattern supplied, less the shrinkage. Patterns are sometimes called models, from the fact that the modeller furnishes patterns for both the brass and iron foundries made from plaster or stucco. Wood patterns made by the pattern-maker are by far the most numerous, including as they must patterns for nearly every cast piece used in producing the multi- tudinous examples of structural, machine, and engine work. Very much of moulding is now accomplished without a full pattern, when a good understanding is maintained between the moulder and the pattern-maker. By a judicious arrangement of strickles, making-up pieces, and sweeps, castings are very often made almost exclusive of a pattern altogether; but this only occurs when the ability of both artisans is above the average. Machines for moulding gears have reduced pattern-making for wheels to a fraction of what it formerly was, and numerous other castings may, by the aid Of a segment and perhaps some core-boxes, be made by them as readily. Besides patterns in iron and brass, numerous others are the production of the modeller, made Pattern Varnish. %&*? Peat. in stucco or plaster, and not a few are, with the aid of template and sweeps, made in loam by the moulder him- self. See Loam-patterns; Backing-out; Spindle. Pattern Varnish. — Usually wood patterns are made from white straight-grained pine, which, while it is an excellent material for working and keeping its shape, is very soft and porous. If such patterns are moulded from without any subsequent treatment, the pores soon fill with sand-dust, which adheres firmly to the moulding-sand and leaves a scarred surface on the mould. To prevent this the patterns should receive a good coat of varnish made from one pound of shellac digested in one gallon of alcohol with as much lamp-black as will color it. After this has thoroughly dried, rub off with fine sand-paper and apply another coat of the varnish slightly diluted with alcohol. See Varnish. Pea-ore. — A form of compact brown iron ore, consist- ing of round, smooth grains varying in size from a mustard- seed to a pea. See Ores. Pease-meal. — Cheap grades of this valuable food finds its way into the foundry, where it is used as a substi- tute for flour. See Flour. Peat is one of the most important productions of alluvial ground, composing the soil of swamps, and con- sisting of the twigs, leaves, and roots of trees mixed with grass, plants, weeds, earth, etc., that have long lain in water, and thereby become decomposed into a blackish- brown mass that may be cut with the spade and dried for fuel. The better qualities contain about 40 per cent of carbon. In Ireland it is known as turf, where it is dug up, dried, and used for fuel. See Fuel. ?eck. £98 Petroleum. Peck. — A dry measure of capacity, and equivalent to two imperial gallons, or 554.548 cubic inches. The fourth part of a bushel. Peening. — The term applied to straightening crooked castings by hammering the concave side immediately oppo- site to the block or anvil upon which the convex side is resting. A spherical hammer-head is the best ordinarily for this purpose, and the blows should be regulated so that the concave side may be sufficiently expanded with the minimum amount of hammering, always commencing at the centre of the bend and working out gradually in every direction. The hammer used for this purpose is termed the " peening " hammer. See Straightening Castings. Pegging-rain iner is sometimes termed the peening- rammer, and consists of an oblong piece of cast or wrought iron of different lengths and widths, and varying from one quarter to one inch in thickness, secured to the end of a piece of tubing or bar iron, with which to force or "ram * the soft open sand of the last filling firmly down upon the preceding course. See Butt-rammer; Bamming. Percentage of Fuel Used for Melting Cast Iron in the Cnpola. — See Ratio of Fuel to Iron. Petroleum. — Previous to the discovery of the value of petroleum as an illuminating agent, the only artificial light for domestic and other similar uses was the tallow-can- dle and dirty oil-lamp; but when whale and other animal oils became too costly, resort was had to natural tar and bituminous slate in order to obtain illuminating-oils, and lamp -oils were for a long time prepared from wood, resin, and other substances. The manufacture of coal-oil was introduced into this country about 1853, being confined to Petroleum. 299 Petroleum. districts where bituminous coal could be mined at a cheap rate. When the value of coal-oil had become recognized, rock- oil or petroleum began to claim attention as a ready means of supplying these oils cheaply, as it was found to be analo- gous in its properties to that distilled from soft coal. It is probable that the petroleum now found in the earth is the product of original decomposition, and of subsequent dis- tillation. Petroleum is, however, rarely found in contact with bituminous strata of any kind, being usually found in fissures of sand rocks, which fissures serve two purposes- one, to give space for the formation and expansion of the hydrocarbon vapor; the other, to furnish receptacles for the condensed oils. To obtain this oil, one of these fissures must be pierced by a well, when in some instances the oil is forced with such velocity as to produce a jet one hun- dred feet high. This oil is found in great quantities on the shores of the Caspian Sea; at Burmah, in the East In- dies; and in Pennsylvania, Canada, and many other parts of the American continent. Fine specimens of naphtha are found in several parts of Italy. The purer kinds of rock- oil, which are almost colorless and very thin, are Naphtha, while the more viscid and darker liquids are Petroleum. The variations of color and consistence in rock-oils is ow- ing to the pitchy and fatty substances being more dissolved in those oils that are most fluid. The word petroleum (rock-oil) is used to designate the forms of bitumen that are of an oily consistence, the bitumen passing by insensi- ble gradations into the volatile naphtha on the one hand, and semi-fluid mineral tars on the other. Among its distil- lates are carbon-oil, paraffine, naphtha, gasoline, and ben- zine. Besides its use for illuminating purposes, it is now recognized as a fuel on both steamships and locomotives, as well as for ordinary domestic and manufacturing pur- poses. The products of petroleum that have proved most Petroleum-furnace. 3(30 Phosphor-bronze. valuable in medicine are the filtered-parafnne residues, as cosmoline, vaseline, etc., widely used, plain and medicated, as ointments. See Bitumen. Petroleum-furnace. — A furnace in which petro- leum alone, or mixed with air or steam, is used exclusively for fuel. See Liquid Fuel; Petroleum. Pewter. — A useful alloy of tin and lead. The com- mon or ley-pewter is 4 tin and 1 lead; plate-pewter, 100 tin, 8 antimony, and 2 each of bismuth and copper ; trifle- pewter, 83 tin and 17 antimony. The best pewter is com- posed of 100 parts tin and 17 antimony. A very hard pewter is 192 tin, 16 antimony, and 4 copper. Tin-and- temper pewter is the best, and is made as follows: Let a a temper " be made from 2 parts tin and 1 part copper, and to every pig of tin weighing about 375 pounds add from 1 to 7 pounds of the temper. See Pewterer's Temper; Tin; Antimony. Pewterer's Solders. — These are of three kinds : the hard and soft pale, and the middling. Hard pale is made from 2 tin and 1 lead ; for the soft pale an addition of 1 bismuth is made; and for the middling pale an equal mixt- ure of both. See Soldering; Solders. Pewterer's Temper. — Tin 2 and copper 1, fused together, make the alloy above named. This temper, mixed in certain proportions with pig tin, produces the pewter named '" tin-and-temper." See Pewter ; Tin. Phosphor-bronze. — This bronze, according to the purposes for which it is intended, contains from 3 to 15 parts tin to 100 copper, with an addition of from \ to &| per cent of phosphorus. This alloy can be remelted any number of times without altering its quality, which is as Phosphor-copper. 301 Phosphor-copper. fine as cast steel, and may be made as hard as that metal or as tough as wrought iron ; in fact, it can be made to any degree of hardness, toughness, or elasticity. It is somewhat difficult to introduce the phosphorus into the crucible, and very much of it is lost in the operation, for which allowance must be made. The action of phos- phorus on bronze alloy is to drive out the oxides, and cause the tin to adopt a crystalline structure, which gives the alloy a higher degree of homogeneousness than in com- mon bronze. Another important feature is that any de- gree of hardness may be obtained by increasing the quan- tity of phosphorus, exclusive of any further addition of tin, the latter metal being sure to separate when used in too large proportions. The more advanced method of in- troducing the phosphorus is by adding phosphor copper, or phosphor tin, specially prepared for the purpose. See Phosphor-copper; Phosphor-ti^; Bronze; Copper. Phosphor-copper is made by lining a crucible with a mixture composed of bone-ash, 18, silica 14, and powdered carbon 4, which is made into a daubing or lining by adding glue-water containing 4 parts each of powdered glass and carbonate of soda. Granulated copper is charged after the lining has been thoroughly dried, and covered with some of the lining mixture ; after which the lid is luted on and the copper melted, when it will be found to contain about 0.52 per cent of phosphorus. The silicic acid acts on the phosphate, the phosphoric acid is reduced, and taken up as freed by the copper. Another phosphor copper, containing about 9 per cent of phosphorus, can be produced by first making a phos- phorous mass by mixing superphosphate of lime with 20 per cent of charcoal and dehydrating the mixture at a dull- red heat. Six hundred parts of this mass are mixed with 975 of copper turnings and 75 of charcoal, and kept at Phosphor tin. 302 Phosphorus. copper-fusion heat for sixteen hours in a graphite crucible. The phosphor copper is obtained in the form of detached granules, which are picked out, re-fused, and cast into cast-iron ingot-moulds. The introduction of phosphorus into the metal is better effected by means of these rich phosphor coppers than by any of the methods adopted for pushing it under the metal in a crude state. See Phos- phor-bronze. Phosphor-tin is a phosphide of tin used as a medium for introducing phosphorus into bronze alloys, and some- times used in conjunction with phosphor-copper for that purpose. It is made by heating 6 parts of phosphorus with 94 parts of moist tin-sponge prepared from the chloride by reduction with zinc. The sticks of phosphorus are first placed in the crucible and the tin sponge pressed hard down. A gentle heat is sufficient for this operation, which ends when the burning phosphorus ceases to give fortn flame, and a coarse, white, crystalline substance has formed, which is the phosphor-tin. See Phosphor-bronze. Phosphorus is one of the non-metallic elements, and is found in nature only in combination — chiefly as the phosphate of lime. It would appear that plants require it, as more or less is found concentrated in their seeds. The bodies of animals contain it in a large degree, being present in the nervous tissues, the urine, the blood, the hair, and in the bones, which contain a large proportion of the phos- phate of lime. The earthy phosphates are important, as they aid in giving stiffness and inflexibility to the bony skeleton. Phosphorus was discovered in urine by Brandt of Hamburg, 1669. It is chiefly made from bones ; when pure it appears like bleached wax, and is soft and flexible at common temperatures, melts at 44° and boils at 289°. Phosphorus, in its combining relation, is more closely con- Piano-plates. 303 Picker. nected with the metals arsenic and antimony than with any of the members of the sulphur group, in which it is commonly placed. See Arsenic; Antimony; Phosphor- bronze. Piano-plates. — The importance of that portion of a piano called the iron frame or "plate" possessing in the highest degree all the qualities requisite for a perfect cast- ing may be better understood when it is known that in pianos of the largest size the sum of the tension of the strings, when stretched in attuning, reaches 33 tons. Ifc is therefore natural to suppose that skill of the highest order is brought to bear on their production. The minor manu- facturers usually contract with some foundry for their sup- ply of plates, but in most cases the restrictions as to weight and finish are so severe that even ordinary profits are never looked for by the founder. Leading firms have them made in their own foundries, where special mixtures of iron, which have been previously determined and tested, are melted down at once, and poured into as many as seventy moulds simultaneously, in order that all may be alike. The chief feature in moulding these castings is the ramming. See Eamming. Picker. — There are various devices for picking out small patterns from the sand, including screws, spikes and spring-lifters, etc., all of which are designated by the gen- eral name of picker The best picker for very small bench- work patterns that are made of wood and do not require duplicating is a fine-pointed steel wire. But if a large number require to be made from one pattern, have a small hole bored well in, or through if the pattern is thin, and use the spring-lifter. A metal plate inserted neatly at the orifice of the hole will prolong the usefulness of the pattern indefinitely. See Screw ; Spike; Spring-lifter. Pick hammer. 304 Pig-iron. Pick-liaiximer. — A steel hammer with tempered points, for use in discovering scoria and other dirt which may be lodged under the thin skin of castings. Pickle. — A pickle for removing sand from castings by sprinkling is made from sulphuric acid 1 and water 4. The castings are sprinkled and exposed to the atmosphere when this is used; but if it is desired to make a bath in which to submerge the castings, then 10 of water may be added to 1 of the acid. Eor cleansing brass castings the pickle should be made from nitric acid 1 and water 3. The vessel in which the sulphuric-acid pickle is to remain should be lined with sheet lead; that for the nitric-acid bath should be of earthenware or glass. Oast-iron work should receive considerable attention after pickling, if it is intended to plate or japan them. The gray accumulation seen on the surface after this process will, if left thereon, be sure to fall off in time, bringing with it whatever has been subsequently applied. Simple water is not sufficient to accomplish a thorough cleansing from this objectionable film ; the castings should be first steeped in a strong hot potash or soda bath, after which hot water or steam may be played over them until they are thoroughly clean, when after being heat-dried they are ready for the plating, japanning, or paint. See Plating ; Dipping; Lacquering. Pig-iron. — Iron in the form of an oblong bar, so called from having been run from a central or main channel designated the sow, which connects with the tap- hole of the blast-furnace, and may be directed to any part of the sand floor of the casting-house, the pigs being branches from the same. According to the fracture, pig Pig-iron Barrow. 305 Pig-iron Tester. iron is classified as gray, mottled, and white iron. See Oast-iron; Grades of Pig-iron. Pig-iron Barrow. — A vehicle for hauling pig iron, usually made high in the front to prevent the pigs from slipping forward on the wheel, and with a flat tray for ease in loading and unloading. Barrows for this purpose and for the transfer of heavy castings are now made by special- ists having the front, and tray made from bent-iron strips set edgewise and securely fastened together, which presents a platform firm and almost indestructible. These barrows can be furnished by the dealers with either one or two wheels attached. Pig-iron Breaker.— The common form of breaker for pig-iron is a heavy sledge-hammer. Many forms of power breakers are employed at the blast-furnaces which might with considerable profit be introduced in the foun- dries, where a large quantity of pig iron must be broken for convenience in charging the cupola. Pig-iron Scales.— The best form of scale, where large quantities of different brands of pig iron must be handled proportionately, is one of sufficient capacity to weigh a whole charge at once. This scale would require a section of railway corresponding to the system throughout the yard and to the furnaces; the pig-iron truck can be run on the scales, and the several quantities constituting a charge could be placed thereon, and be at once conveyed in bulk up an inclined plane to the cupola scaffold or on the level to the elevator platform. Pig-iron Tester is a simple form of machine for ascertaining the transverse strength of cast iron, some having an indicator attached by which the elastic limit is Piling. 306 Pin and Cottar. measured also. This is an excellent contiivance for obtain- ing a comparative test of the iron supplied subsequent to charging in the cupola by simply melting a small quantity in the crucible and casting one or more 1-inch-square bars, the strength of which may be discovered by the machine. Density, tendency to chill, and shrinkage may also be observed in the cast bars, and thus by these mechanical means a fair knowledge of the iron may be obtained before taking risks in the cupola. See Testing-machine. Piling. — Puddled balls, after being shingled, are called blooms, which after passing through the puddle-bar rolls are called puddle-bar. For the best iron these bars are cut into short lengths and made into piles, to be reheated and again passed through the forge-rolls, after which the iron is again cut, piled, and heated, and then passed through the mill-train, the finishing-rolls being the last rolls in the train. For beams, rails, etc., the piling is arranged to suit the form required, the pile consisting of different grades of iron, according to the desired quality of the finished product. See Malleable Iron. Pin. — A common name in the foundry for a gate-pin, also a flask-pin. See Gate-pin; Snug. Pin and Cotter. — An arrangement for pinning flasks, consisting of a wrought iron or steel pin, with forged or turned shoulder, to rest in holes provided in the drag, to which it is made fast by a nut which is screwed on the small end of the pin. The cotter-hole is forged in the pin, so that when the cotter is driven home its upper edge touches the upper part of the hole, while the lower one rests on the -lug or flange of the cope, and clear of the hole entirely; thus by this means drawing cope and nowel close together and holding them. See Snug, Pincers. 307 Pitch. Pincers. — An instrument for grasping objects, draw- ing nails, etc. Two handles work the jaws, which are held in position by a pivot. Pinch-bar. — A long bar of steel or iron, fashioned at the end, suitable for raising weights or propelling vehicles. See Lever. Pinchbeck. — An imitation gold, composed of copper 5, zinc 2. See Gold ; Tombac. Pipe-clay. — A clay of a grayish-white color, greasy to the touch, very plastic, and free from iron and other -impurities. Its principal use is for making white pottery and tobacco-pipes. See Feldspar; Kaolin; Pottery- moulding; etc. Pipe-monlding. — See Cast-iron Pipes. Piston-blowers are machines which force the blast with every alternate motion of the piston. See Blower. Pit is a general foundry term for all holes dug in the floor in which to form moulds in green-sand, or close together and cast such as are formed in dry sand or loam. In the former instance the hole is dug, the pattern inserted, and the sand rammed therein, as described at " Bedding In " (q.v.), while in the latter it may be required only to lower the mould down to a suitable depth for casting (see Dry-sand Moulding) ; or, as in the case of a loam-mould, it may be necessary both for closing, and binding the walls sufficient to resist the pressure of the molten iron within by ramming sand firmly in the space betwixt the pit-sides and the mould. See Loam-moulding ; Curb ; Eamming. Pitch is the black residue remaining after distilling wood-tar. Charcoal is made by covering piles of wood to Pit-coal. 308 Plaster-cast. partially exclude the air; this is fired, and the volatile con- stituents of the wood gradually distil off, leaving the char- coal. If it is desired to produce tar, the resinous woods are employed, and the pit-bottom is made concave. During combustion, the liquid products are separated, collect at the bottom, and flow out through a trough into a reservoir. They consist of tar, acetic acid, and oil of turpentine. When the tar is distilled, essence of turpentine is separated, and what remains is pitch. See Tar. Pit-coal. — The name given to mineral coal to distin- guish it from charcoal. See Coal. Plaster. — Sulphate of lime or plaster of Paris. See Gypsum. Plaster-cast. — To take a plaster-cast of any figure, bust, medal, etc., it is only necessary to obtain a mould by pressing some soft substance upon it, which when it has hardened maybe filled with plaster; the latter soon hardens, and a representation of the original is obtained. The sub- stances used for forming such moulds are various: for some objects a composition of beeswax, rosin, and pitch may be poured round it ; for very small objects, wax alone, or the crumbs of new bread, will answer ; but for larger ones it is necessary to provide moulds of the plaster itself, or clay may be substituted. A cast of a person's face is obtained by first securing the hair at the back, inserting paper tubes at the nostrils for breathing, and oiling the face, the person lying on his back. The thin plaster is then carefully spread one-fourth inch thick all over, taken away when set, and used for obtaining a clay model, from which to make a plaster-mould, which serves as the matrix for the final cast, and which must be divided at suitable places for easy withdrawal from the face. See Statue-foukdikg, Plaster Match-part. 309 Platen. Plaster Patch-part.— A joint board or match-part prepared in plaster. See Match-part. Plate. — Foundry plates are of two kinds principally, being for the purpose of carrying or covering moulds. Those used for carrying are usually plain open-sand plates, with handles or lugs made in a form suitable for the lifting tackle used; whilst the covering plates have dabbers or prickers cast on them for sustaining the loam or sand with which they are covered on the mould or face side. See Prickers ; Loam-moulding ; Open-sand Moulding. Plate Brass is cast brass for rolling into sheets, and is composed of copper 16, zinc 3. See Brass. Plate-moulding is simply dividing the pattern to be moulded exactly at the joint or parting, and placing the halves opposite to each other on an iron plate or a board, which is provided with pin-holes exactly corresponding to the interchangeable flasks to be used. Cope and nowel may then be rammed respectively, cope lifted off, plate taken away, and the cope again pinned to place. If dis- tinct plates are made for each side the operations are facilitated somewhat, as all the nowels can be completed at once and the copes follow in succession: the advantage in the latter method is, that the plate is withdrawn from the mould in both cases, while in the former the cope is lifted off the plate -a bad feature when the patterns are not com- paratively plain. When more than one pattern are thus treated, and all run from one common gate, it is customary to call it a card of patterns 4 . See Match-plate. Platen, in moulding-machines, is the upper diaphragm or plate, against which the flask with its containing sand and pattern is forced by pressure from below. See Mould- ing-machines. Slates of Metal. 3l0 Plating Plates of Metal.— For weight of a superficial square foot of different metals, see Weight of Plates. Plate-wheel. — A wheel having the rim and hub con- nected by a plate instead of arms. Platform. — The scaffold round the cupola, built for convenience in charging. If possible, they should always be of sufficient area to accommodate the stowing of all the iron, fuel, material for repairs, etc., required for one day's melting at least, for which reason there should be no mis- take made as to the strength of such structures. If there be a system of tracks in the yard, an incline from the platform will serve to communicate therewith. See Pig- iron Scales; Charging- platform. Platform-cranes are walking cranes erected on trucks which run on rails or road. See Cranes. Platform Scale. — A weighing-machine provided with a platform on which to place the object to be weighed. See Weighing-scales. l Plating. — The coating of one metal with another. This is done in some cases to protect the underlying metal from oxidation; in others, that the properties of two metals, such as strength and lustre, may be combined in one object; but in the majority of cases it is done that some inferior metal may appear like a superior one. Originally, silver-plate was made by wiring thin plates of silver to ingots of German-silver or copper, and submitting to a soldering temperature in a plating-furnace to unite the two surfaces. The ingot was then rolled down to a sheet, in which the relative thickness of the two metals was maintained. This method of plating has now become almost extinct, being superseded by electro-plating and Platinum. 311 Platinum. gilding, which covers the object with a film by the aid of electricity. To coat articles with silver, a bath is made of cyanide of silver 1 part, to 2 or 3 parts of cyanide of potassium, dissolved in 150 parts of water. The article to be plated is made the negative pole, and a piece of silver hung in the bath forms the positive pole. Articles are gilded by employing a solution of the double cyanide of gold and potassium, and suspending plates of gold in the solution. A proper coating takes from three to six hours, but any thickness may be given by continuing the operation. From \ to 1 ounce of silver suffices for one square foot of plating. Other metals besides copper, silver, and gold can be electrically deposited from their solutions, as, for instance, the coating of iron with zinc, a solution of the sulphate of zinc being employed for that purpose. The deposition of nickel from the sulphate of nickel and ammonium is deposited as a very thin but extremely hard coating by this process, so that innumerable articles may be protected from tarnishing and corrosion, as nickel will not readily tarnish, even in a very moist atmosphere. See Electro-plating; Nickel-plating; Gilding. Platinum is a rare metal, invariably found native, and usually associated with palladium, iridium, and rho- dium. It occurs also alloyed with gold, copper, iron, and lead. Found chiefly in the mines of the Ural Mountains, Brazil, and Mexico. Its color is grayish white, almost like silver in appearance. It is ductile, takes a good polish, and is as malleable as gold or silver. Its most useful qualities, however, are the difficulty of fusion and its absolute resistance to the action of almost all acids; but it may be slowly dissolved by aqua regia. It will not oxidize in air at any temperature. Its specific gravity is 21.5. Platinum with steel forms an alloy that is exceed- ingly hard. See Metals, Aqua Regia ; Platinum Alloys. Platinum Alloys. 312 Plumber's Solder. Platinum Alloys.— These alloys are almost non- oxidizable, and may be prepared by the usual methods of melting, without flux. Nickel 100, tin 10, platinum 1 — suitable for table-ware. Nickel 100, tin 20, platinum 1, silver 2— a good mixture for bells. Nickel 100, tin 20, platinum 20 — optical and similar instruments. Another non-oxidizable alloy of platinum is composed of nickel 60, brass 130, platinum 70. Platinum alloys readily with steel, and produces a very tough and fine-grained product when present to the extent of 1 per cent. See Silver; Silver Alloys ; Silvering ; Nickel. Platinum Steel. — See Platinum Allots. Pliers. — A kind of pincers with which to seize, bend, break, or cut small objects. Plinth. — The square member at the bottom of the base of a column. Also, the projecting band forming the base of a wall, etc. See Column. Plug. — A conical clay bott, or bod, secured to the end of the bott-stick, with which to plug the tap-hole of the cupola. See Bott-stick. Plumbago. — See Black Lead; Graphite; Pacing. Plumb-bob. — Usually a conically shaped piece of lead or iron, suspended on a cord, with which to obtain a perpen- dicular to the horizon. See Level. Plumber's Solder.— Solder for lead is composed of tin 1, lead 1| ; flux with tallow or rosin. For tin : tin 1, lead 2: flux with rosin and sweet-oil. A useful solder for general purposes is made from lead 5, tin 3, bismuth 1. See Soldering ; Solders. Pneumatic Cranes. 313 Polling. Pneumatic Cranes. — Are being extensively used because of their convenience, especially for moderate duty. The transmission of air under pressure results in none of the annoyances from leakage incident to steam and hydraulic piping, and obviates all trouble in disposing of the exhaust, as this may be allowed to discharge anywhere without inconveniencing any one. See Cranes. Pneumatic Lifts. — These lifts are now becoming common among blast-furnaces in different parts of the world, as compressed air is readily obtained from the blowing-engines which supply the furnaces. A wrought- iron cylinder, with its top end closed, somewhat longer than the distance to be travelled is suspended in a tank by counter- weights, after the manner of a gasometer. Air at three or four pounds above the atmospheric pressure is forced into the tank through a pipe. The load is lifted to the height required, and as the whole of the working parts are balanced, the amount of power required is only what will be sufficient to elevate the load. The return stroke is obtained by allow- ing the air to escape through a valve into the atmosphere, the empty wagon being weight sufficient to lower the bell in the tank. The motive power for the Grjers pneumatic lift is obtained from a pair of double-acting air-pumps, the lift being effected by the pressure of the atmosphere acting against a vacuum in a cylinder, the empty wagon being returned by the compression of air on the under side of the piston. See Elevator. Pocket. — The temporary exteusion of a flask in one or more direction, to fit it for use on some special casting for which it had not been originally designed. Polling.— The operation of mixing metal by vigorous stirring with a rod of iron or pole of wood. Wood-polling Polishing Substances. 314 Porcelain Moulding. is more effective especially when the wood is green, as it yields its juices in a gaseous form which causes the metal to bubble freely, and the operation is accelerated wonder- fully. See Copper. Polishing Substances. — The substances used by the worker in gems and precious stones are principally powdered diamond, sapphire, and ruby; for the several operations in the various metals, powdered corundum, emery, pumice-stone, flint, tripoli, rottenstone, chalk, oxide of tin, oxide of iron, etc., are used by metal-workers. For the first operations in glass-polishing, silex sand and water are used between the rubber and the glass, after which different grades of emery, and finally the putty powders, or oxide of tin. See throughout the work for a description of the substances mentioned. Porcelain Moulding. — Not many branches of in- dustry are of higher antiquity than that of the potter, as the plasticity of natural clays and their hardening when exposed to heat are properties which were known in the earliest ages. There is a marked difference between true porcelain and earthenware, the body of the former ware being very compact and translucent, and breaking with a conchoidal fracture, which shows there has been partial fusion. The glaze which is applied to porcelain to produce the smooth surface evidently blends with the substance of which the body is composed. This cannot be said of earthenware, which, when it is broken, shows an open and somewhat earthy fracture, and the glaze can be readily detached. The clay employed in porcelain-making is derived from de- composed feldspar, no other kind being pure enough; this is white, and free from ferric oxide. To diminish the con- traction which this substance undergoes in the fire, finely Porosity. 315 Porosity divided silica made from pulverized flints is added, together with a proper proportion of feldspar or other fusible ma- terial, also reduced to an impalpable powder. The ware is moulded in plaster-of-Paris matrices, or formed by means of a vertical spindle and table (potters'-wheel), and is par- tially dried in the air, still more by heat, and then con- verted into what is termed biscuit by exposure to a higher temperature. This porous biscuit is in a condition favor- able for receiving its glaze, which is either ground feldspar, or a mixture of silica, gypsum, and some porcelain clay diffused through water. After dipping in this mixture the water sinks into the ware, leaving an evenly spread surface of the powder; after it has again dried it is fired at an ex- ceedingly high temperature. The manufacture of porcelain outside of China is of modern origin, but the Chinese have practised the art from the beginning of the seventh century, their work being in some respects unequalled. The materials employed by them are kaolin, or decomposed feldspar; petuntze, or quartz reduced to fine powder; and the ashes of fern, which con- tain potassic carbonate. See Pottery-moulding. Porosity.— Pores are small interstices between the particles of matter which compose bodies, and are either empty or filled with some insensible medium. Condensa- tion and rarefaction are only performed by opening and closing the pores. What shape the atoms of different bodies are, we have no means of determining. Pores are often visible to the naked eye, as in sponge and pumice- stone; but in gold and granite they are too minute to be detected. If we place a little water on chalk or cloth it disappears; in a certain sense it penetrates them, but it does not enter into the solid particles; it only passes into the vacant places or pores. A piece of iron is made smaller by hammering. This proves its porosity. Its particles could Portable Furnaces. 316 Portable Furnaces. not be brought into closer contact if there were no in- terstices between them. Mercury passes through lead, and water may be forced through the pores of gold. So that, though matter is essentially impenetrable, it is also uni- versally porous. See Particle. Portable Furnaces. — A French portable brass furnace consists of a furnace with a fixed crucible, and arranged so that the castings may be poured direct from the crucible without removing it from the furnace, the two moving simultaneously from the furnace to the moulds, and vice versa. The metal may be fused by the use of fuel, the ashes of which can be cleaned out of the furnace before casting, or the latter annoyance may be obviated by con- necting with a regenerative or a gas-blast system. That part of the furnace which contains the fixed crucible is set in standards provided with bearings for the trunnions to rest in, and the standards being secured to a suitable truck, the whole is run on the tracks for casting, which operation is readily performed by means of a small hoist attached to one of the standards, which tilts the furnace sufficient to allow the metal to flow from the crucible at its upper edge. See Gas-blast Furnace; Brass Furnace. A very handy and serviceable portable cupola for melting cast iron or other metals may be made and mounted on wheels, for use on special occasions, such as mixing for tests, or taking off a very light heat occasionally. The shell could be of T V plate, and large enough in diameter to measure about 18 inches diameter when lined with 4-inch bricks. Its height might be 60 inches, with wind-box attached, covering 3 tuyere holes 2} inches diameter, pierced about 16 inches from the bottom plate. A small fan-blower set back of the cupola could be arranged for running either by hand or power. Made in this manner, the refuse material contained in the cupola, when done Portable Ovens. 317 Potash. melting, would have to be drawn out at the front or spout; but this might be obviated by suspending the cupola on central trunnions, and by this means eject the whole con- tents at the mouth. The latter method is a great help in cleaning and repairing so small a cupola. With efficient blast and good management such a cupola should melt 1000 pounds per hour. See Cupola. Portable Ovens. — Brass and iron moulders' drying stoves, or portable ovens, are supplied by the dealers at very low prices. They are made in sections, which fit into each other, and are excellent contrivances for drying small cores. See Oveks. Portland Cement.— So called from its near resem- blance to Portland stone in color. It not only possesses the property of setting more quickly, and has greater power of cohesion than the natural cements, but it may be used with a superabundance of water in the form of grout, which they cannot be. This cement is made from Westmacott's patent carbonate in combination with chalk, gray, and all other limes. All the carbonic acid being removed from the lime in its burning, 75 per cent of this acid is restored by its mixture with the prepared patent carbonate. Pot. — A common name in foundries for the crucible. See Ckucible. Potash. — This substance exists in plants, combined with other organic acids. The plants being burned de- stroys the combination, the organic acids being decomposed into carbonic acid and water, and the liberated potash unites with some of the carbonic acid formed by the com- bustion, thus producing carbonate of potash. This salt is highly alkaline, is used to prepare caustic potash, and for Potassium. 318 Pot-metal. the manufacture of soap, glass, etc. Wood-ashes furnish from 20 to 50 per cent of their weight of carbonate of potash, being obtained from them by leaching and boiling the solution to dryness in iron pots. See Alkali; Ashes. Potassium. — Potassium was discovered by Sir Hum- phry Davy in 1807, together with sodium, barium, stron- tium, and calcium. Before this time the alkalies and alkaline earths had been considered as simple bodies, and it is to him we owe the discovery of their compound nature. He obtained it in very small quantity by exposing a piece of moistened potassic hydrate to the action of a powerful voltaic battery; the positive pole gave off oxygen, and metallic globules of pure potassium appeared at the nega- tive pole. Potassium is a brilliant white metal with a high degree of lustre; at the common temperature of the air it is soft, and may be easily cut with a knife, but at 32° F. it is brittle and crystalline. It melts completely at 130° F. and distils at a low-red heat. It floats on Avater, its specific gravity being only 0.865. It oxidizes instantly in the air; takes fire if thrown upon water. Potassium decomposes nearly all compounds containing oxygen if brought in contact with them at high temperatures; hence to preserve it pure it is kept under naphtha, a liquid containing no oxygen. See Metals; Alloys. Potato-flux. — If a raw potato is fastened on the end of a bar and thrust into a ladle of cast iron and held there, the escaping steam will cause a violent ebullition, which thoroughly mixes and cleanses the mass. The dirt rises to the surface, and may be removed with the skimmer. See Polling. Pot-metal. — An alloy of lead and copper, and called pot-metal when the alloy consists of these two metals only, Pottery-moulding. 319 Pottery-moulding. exclusive of any other. The object in making pot-metal is to use as much lead as possible, and thus obtain a cheap compound for use on the commonest class of work, such as beer-taps, etc. A mixture of copper 16, lead 2 makes a ductile alloy of a red color. When the mixture consists of copper 16, lead 4, its redness and ductility are very per- ceptibly decreased. Copper 16 and lead 6 is the real pot-metal, and is commonly termed "dry pot-metal," or cock alloy. Beyond this proportion of lead there is danger of the lead separating from the alloy as it cools; but by careful manipulation it is possible to make a compound of copper 16 and lead 8, which is termed "wet pot-metal." The addition of a small proportion of tin to wet pot-metal will prevent the lead from separating, as tin may be mixed in almost any proportion with the alloy; and if the mixture consist of copper 16, lead 7, antimony 1, the same effect is obtained; but it is no longer the true pot-metal when these additions have been made. See Copper; Lead; Anti- mony; Tin. Pottery-moulding". — Pottery is a term applied to all objects made in clay and baked. The potter's art has been practised by even semi-barbarous races from the remotest period. Vases of baked earthenware were in use at the earliest period of Egyptian civilization, and Babylon and Assyria were noted for their pottery, which was of a red color and more refined shape than that of the Egyptians. The Greeks claimed the invention of the potter's-wheel. Etruscan ware, famous for the bas-relief ornaments moulded — evidently from metal ores on its surface, was in use 500 years B.C., and was the source of Koman pottery. The existence of unglazed earthenware in North America dates from remote times. This ware is of the rudest kind, and bears a striking resemblance to the earliest specimens of Northern Europe. Mexico and Peru were excellent Pottery-moulding. 320 Pottery-moulding. workers in pottery in the earlier ages, to which the mould- ing, coloring, and ornamentation of preserved specimens bear ample evidence; but they never acquired the art of glazing. The knowledge of glazes was first acquired by the Egyptians and Assyrians, and descended from them to the Persians, Moors, and Arabs, the latter race intro- ducing into Spain the art of making glazed tile about 711 a.d. The first appearance of Italian enamelled faience, the precursor of modern porcelain, dates about 1420, being then used by Lucca della Kobbia for subjects in relief. A century later the works of Kaphael were copied on plates and other ware, and painted in brilliant colors. Enamelled ware passed into France in 1590 with Catherine de Medici. The celebrated Palissy discovered at Saintes, 1555, the art of enamelling a gray paste, from which he moulded fruit, animals, etc., for decorating dishes. Glazed earthenware delft was first made at Delft about 1360; but none of these wares was equal to the Chinese porce- lain, which, brought to Europe by the Arabs in the thirteenth century, became known in Italy 1330, in France 1370, and later in England. Wedgwood, the great English potter, was born at Burslem in Staffordshire 1730. Pottery and porcelain differ chiefly in this, that the superior quality of the materials used for making the latter gives it the peculiar quality of translucency it possesses. (See Porcelain.) Inferior materials used for making pottery, include phosphate of lime, bone-ashes, calcined flint, etc., which are added to the native clays. Besides the common methods of moulding by the wheel and forming with the hand, improved moulding machinery has been introduced, which facilitates operations to a great extent. Large numbers of articles are made in plaster- moulds, which being porous rapidly absorbs the moisture from the creamy clay with which they are filled ; a stopper Pound. 321 Precious Metals. at the bottom of the mould is withdrawn when it is known that a sufficient thickness of the paste has adhered to the mould, and the superfluous paste runs out. If it is found that the article thus produced is not thick enough the operation is repeated. Another method of obtaining the desired form from plaster-moulds is to roll the clay into thin sheets and press it upon the surface with a sponge. See Porcelain. Pound. — The pound is a standard weight, and consists of 16 ounces avoirdupois, or 12 ounces Troy. The avoirdu- pois pound weighs 7000 Troy grains, and the Troy pound 5760 grains. Pouring-basin. — A reservoir formed in sand to receive the molten metal from the ladle, from whence it passes to the mould by whatever system of running- gates is suitable. See Basin; Gates; etc. Power-hammer is a hammering machine operated by steam, air, or some other mechanical contrivance. See Hammer. Prairie Hay. — This hay is now obtained in large quantities and spun into ropes suitable for wrapping on core- barrels. Spools of this ready-made rope containing from 300 to 350 feet may be purchased from any of the dealers in foundry supplies at a very low price. See Hay-rope ; Core-barrel. Precious Metals. — Gold and silver are denominated precious metals because their peculiar properties pre- eminently fit them for becoming standards of value. Even barbarians are cognizant of their superiority over all other metals. They have a brilliant lustre, are hard, and of Precious Stones. 322 Pressing Fluid Steel. high s}Decific gravity, not subject to oxidization, fusible, malleable — the two latter properties permitting them to be cast or stamped with designs ; and, besides all these superior qualities, they are found pure. See Gold; .Silvek. Precious Stones. — The hardness of precious stones, beginning with the hardest, is as follows: 1. Diamond; 2. Euby; 3. Sapphire; 4. Topaz; 5. Hyacinth; 6. Emerald; 7. Garnet; 8. Amethyst; 9. Agate; 10. Turquoise; 11. Opal. Precipitation. — When a body dissolved in a fluid, either through the action of the air, or of a gas, or of a chemical agent in solution, is made to separate and fall down in the concrete state, this falling down is called precipitation, and the matter thus separated is called a precipitate. See Solubility. Pressed Fuel. — Many loose substances which other- wise would be wasted are mixed with cements composed of either coal-tar, cow-dung, pitch, clay, or other combina- tions, to bind them together, after which they are subjected to pressure, and solid fuel is produced from the mass in the form of bricks or balls. Pulverized coal is treated in this way. Pressing Fluid Steel.— The invention of Sir Joseph Whitworth for the production of sound steel ingots consists in applying pressure, by powerful hydraulic ma- chinery, while the metal is solidifying in the ingot. As from 6 to 20 tons per square inch is the amount of pressure required to produce a sound ingot in this manner, the moulds employed are of special construction. The main cylinder is strengthened by steel bands on the out- side, and the inside or iron lining is composed of cast-iron Pressure-blower. 323 Pressure moulding. lagging, which receives a coat of very refractory loam. This system of lagging permits the gases to escape freely, as they are forced out by the enormous pressure exerted. See Ingot. Pressure-blower. — A blowing-engine that gives a positive blast, and measures and forces forward at each revolution a fixed quantity of air, whether the pressure be high or low, or the speed fast or slow. See Blower. Pressure-forging. — Usually a substitution of hy- draulic or other machinery for the regular processes of hammering and rolling metals into the required form. Pressure-gauge. — A pressure-gauge for showing the amount of pressure in the wind-box and pipes of the cupola consists of a glass siphon tube, with equal legs, half filled with mercury; one end is cemented into a pipe which enters the wind-box, the other is open to the atmosphere. If a stop-cock is provided, it may be shut off at pleasure. The wind acting on the mercury in one leg of the gauge presses it down, and it rises correspondingly in the other leg. The difference between the two columns is the height of mercury which corresponds to the excess of the pressure in the wind-box above the pressure of the atmosphere. If eight ounces per inch be allowed for the length of this column, the effective pressure of the blast in ounces per square inch is obtained. Therefore all that is necessary for graduating the tube is to mark it off in one-eighth-inch divisions, and each division would represent one ounce of pressure. See Blast- gauge. Pressure-moulding. — The several moulding-ma- chines which operate by forcing the sand into the flask betwixt the table and platen may be taken as examples of pressure-moulding, effecting by machine pressure what Pressure of Blast. 324 Prickers on Plates. has hitherto been accomplished by hand-ramming. See Moulding-machines. Pressure of Blast.— See Blast-pressure. Pressure of Molten Metal. — The conditions of liquid pressure exist in moulds exactly the same as in any other vessel in which liquids may be placed. Solids trans- mit pressure only in the line in which it is exerted; liquids transmit it in every direction — as may be noticed when in casting the poured metal escapes at every riser, at equal velocities. Molten metal influenced by gravity alone presses in all directions, as will be seen by the following: Let a covered mould be filled with molten metal, and main- tain a pressure by a raised runner-basin; if this mould be tapped at the bottom the metal will rush out, — this proves a downward pressure; if it be tapped on the side, the metal rushes out, showing a lateral pressure; and if it be tapped on the top, the metal will escape also, showing an upward pressure. The pressure of molten metal in every direction is proportioned to the depth; hence the necessity of in- creasing the strength of moulds towards their bases, and additional precautions being taken to hold down the cope when large areas are subjected to a considerable head- pressure. See^VEiGHTiNG Copes; Hydraulics; Hydro- static Bellows. Pricker. — A moulder's tool with which to pierce the sand to permit the escape of steam and gas. See Vent- wire; Venting. Prickers on Plates. — These are frequently called dabbers or prods by moulders. If the plate to be used for covering a loam-mould is only to form a plain surface, the prickers need only be long enough to carry as much sand as will prevent the heat from damaging the plate when the Prince Rupert's Gold. 325 Printing. mould is cast. In the event of projections of loam or sand having to be sustained safely, the prickers are made long enough to reach such projections. The method of forming prickers is by thrusting a pricker-pattern into the sand to the required depth, after the outer edges of the plate have been formed, the bed having been previously prepared to the required density to receive it. See Loam-moulding ; Plate; Covering-plate. Prince Rupert's Gold. — A kind of pinchbeck; copper 3, zinc 1. See Gold; Tombac. •Prince's-nietal.— An alloy for cheap jewelry; cop- per 18, zinc 7. See Gold; Tombac. Print. — A boss or hub on a pattern indicating the place for a core of that shape and dimension. See Core- print. Printing. — Printing mould surfaces is a process re- quiring more than ordinary judgment and dexterity on the part of the moulder to do it well. It is usually practised in, foundries that make a specialty of fine register and stove-plate work, where the patterns are very thin, with more or less decorative work on their front surfaces. Any attempt to fasten the blacking on these surfaces success- fully with the brush or tools is next to impossible, and it is certain that returning the pattern for that purpose is not only productive of better work, but more expeditious also. A heavy lead or charcoal that adheres well to the sand is first dusted over the surface and the dust allowed to sub- side. In the mean time the moulder has brushed his pat- tern, and perhaps warmed it a little ; a dusting of lighter blacking is applied, and the pattern returned, rapped down, and withdrawn, leaving a thin coat of carbon evenly dis- Prods. 326 Puddled Steel tributed on every part, and having no other blemishes than are contained in the pattern. See Return-pacing. Prods. — A common name in some parts for the prick- ers on a loam-plate. See Prickers. Projectiles are such bodies as, being put in a violent motion by any great force, are then cast off or let go from the place where they received their quantity of motion; as a shell or shot from a gun. There are various descriptions of projectiles, spherical and elongated, some being solid, others hollow; also case-shot, etc. See Shot; Shell; Ordnance. Propeller. — An instrument placed at the back part of a steam-vessel for the purpose of propelling her through the water. See Screw-propeller. Puddled Steel, or Semi-steel, is produced by the decarburization of cast iron in the puddling -furnace. Krupp, of Germany, makes the bulk of his steel by this process, using irons rich in manganese and carbon, which are suited for conversion into steel. The puddling process for steel is very like that for malleable iron, except that the former is conducted at a lower temperature and needs more careful manipulation. There is no previous refine- ment of the ii'on to be operated upon when steel is pro- duced by puddling. About 400 pounds are first melted, mixed with silicate of iron (slag), and kept stirred with a rabble. During this operation the carbon contained in the iron is oxidized by the oxygen present in the cinder, pro- ducing carbonic oxide, which as it escapes causes the ap- pearance of boiling. When this boiling is general through the mass, the temperature is increased until the appearance of incipient solidification occurs; the temperature is then Puddle rolls. B27 Pumice stone. reduced, and the ordinary process of balling proceeded with. The work in this case demands more than or- dinary skill. This steel, after being made into bars, is cut up and remelted in crucibles, in order to produce cast steel. See Malleable Iron; Crucible Steel. Puddle-rolls are the pair of rolls on the left of the train, usually called the rougliing-rolls. See Malleable Iron ; Bolls ; Train. Puddling.— See Malleable Iron. Puddling- furnace. — A furnace for separating the carbon and other impurities from cast iron. This furnace is usually of the reverberatory kind, and in the process the fire is not mingled with the metal, as in the case of smelt- ing, the material being melted by causing the flame to im- pinge upon it on its way from the fireplace at one end to the chimney at the other. See Malleable Iron; Rever- BERATORY FURNACE. Pug-mill. — A mill used by potters and brickmakers to cut up and blend the clay. Pug-mills are of various designs, and some of them are capable of performing several operations successively, as cutting the clay, grinding and tempering it, and finally ejecting a limited quantity into the moulds below. Pulverized Coal. — See Pressed Fuel. Pulverizer. — See Sand-pulverizer; Rock-crusher. Pumice - stone. — A spongy lava of a very porous nature, and so light that it will float on water. It is found in volcanic districts, being composed chiefly of silica and Pure Iron. 328 Quarter-turn Pipe. alumina, with some potasli and soda. See Polishing Sub- stances. Pure Iron is of very rare occurrence, aud can be ob- tained only by purely chemical methods in the laboratory. See Native Iron". Putty is whiting and linseed-oil kneaded into a thick paste. See Whiting. Putty-powder.— The peroxide of tin, made by skim- ming the oxidized surface from melting tin, which when cold is reduced to a fine white powder. The particles be- ing very hard, it is used as a polishing material, and also as a coloring for enamels and glass. See Polishing Sub- stances. Pyrites. — A native compound of metal with sulphur. See Sulphur. Pyrometer. — An instrument for measuring tempera- tures beyond the ability of mercury to indicate. The older instruments of this class, such as the Wedgwood, Daniell's, etc., have been superseded by others based on the expansion of gases or on the electrical properties of bodies. Q. Quadrant is the fourth part of the circumference of a circle; an arc of 90 degrees. Quart. — The fourth part of a gallon. Two pints make one quart. Quarter-turn Pipe.— A curved section of piping, the ends of which finish at an angle of 90°. Quart*. 329 Quicklime, Quartz.— The purest condition of silicon is that of quartz, in which it forms hexagonal crystals terminated by six-sided summits. It is a very abundant and widely dif- fused mineral. Quartz rock is mainly composed of it, and it is in this substance that gold is more frequently found than in any other. Quartz is the principal constituent of nearly all granites, as well as the numerous sand- stones, limestones, trap-rocks, etc. Sands of both desert and sea-shore, and the common flint, are chiefly composed of it ; and many stones, as the agate, amethyst, carnelian, chalcedony, jasper, rock-crystal, etc., are simply varieties of quartz. It is thought that a great deal of the silica which exists in nature has been originally deposited in the soluble condition. The structure of the chalcedony, etc., proves that they were formed by a solution of silica having penetrated into a cavity in the surrounding rock and there crystallized. See throughout this work for a description of the substances mentioned. . Quartzite. — A sedimentary sandstone which by meta- morphic action has been converted into a hard rock possess- ing a highly refractory nature, for which reason it was formerly employed for constructing blast-furnace hearths, etc. See Sand-stoke. Queen's Metal. — For teapots, spoons, etc. Tin 100, bismuth 1, antimony 8, copper 4; or, tin 9, bismuth 1, an- timony 1, lead 1. See White Metals; Britannia Metal; Tombac; German-silver. Quick-clipping Acid. — Sulphuric acid 1 gallon, nitric acid, 1 gallon. This is for brass which has been or- molued. See Dipping. Quicklime. — Limestone or carbonate of lime de- Quicksilver. 530 Ramming, prived of its carbonic acid. Unslaked lime. See Lime; Limestone, etc. Quicksilver. — A name given by the ancients to the metal mercury. See Mercury. K. Racks for Cores. — Brackets projecting from the walls of the foundry oven on which to place the cores dur- ing the process of drying. There is nothing more detri- mental to the business of core-drying than a scarcity of suitably arranged racks along the walls of the oven; the carriage may also be utilized for this purpose in some in- stances. When this is practicable, large numbers of cores may be conveniently dried simultaneously with the moulds, etc., with which it may be loaded. See Oven - ; Carriage. Radius. — The radius of a circle is just half its diam- eter; in other words, it is a straight line drawn from the centre to the circumference. See Circle. Ranimiug. — The process of ramming moulds is by no means a simple operation. Inelegant and laborious as it may seem, it is at the ramming stage of the moulder's art that the foundation is laid for the successful achieve- ment of the task he undertakes; and nothing but sound judgment based upon intelligent practice is able to qualify the moulder in this particular department of his trade. See Butt-rammer; Peen-rammer. Much subsequent repairing and finishing of the mould may be avoided when strict attention is paid to the neces- sity of ramming each portion of the mould in exact accord- ance with absolute requirements. For light castings of a duplicate character it is essential that the ramming be sys- Hamming. 331 Hamming. tematized in order that each casting shall be a true copy of its fellow in all respects, but particularly so in reference to weight, where due regard must be had to their being as light as possible. This of course can only be accomplished by discovering the point where the hardness of the mould surface interferes with an uninterrupted flow of the molten metal over it. Nearly all classes of light work may be suc- cessfully moulded without subsequent venting if due at- tention be given to the grading and tempering of the sand used, and ramming no harder than is absolutely necessary; careful tramping with the feet being all that is requisite in countless instances. The ignorant moulder pounds away, regardless of the differences consequent on whatever changes may be made in the material he works with. Not so the intelligent one : he is closely observant of all these things, and regulates his ramming accordingly. The admirable precision and duplication of similar castings produced on the moulding-machines furnish ample evidence of the truth of the aforesaid, as the w T hole process of moulding by this method consists in placing a measured quantity of sand in the flask every time to be operated upon by the rammer, which with mechanical precision presses it down into the flask and around the pattern with an exactness impossible of attainment by hand- ramming. It is very evident that whatever superiority machine-made castings possess over those made by hand- ramming, it must all inevitably result from the more effi- cient and exact ramming performed by the machine, as the entire operation consists of introducing an exact quantity of sand into the flask, bringing on the pressure, and withdrawing the pattern, — all of which operations are, in the majority of cases, performed automatically. Subse- quent treatment of these moulds is limited to the placing of cores and closing the parts for casting, no hand -finishing whatever being required. See Moulding-machines. Hamming. 332 Ramming. The ramming of heavy green-sand work undoubtedly calls for very superior ability, as not only must the mould face be made of the proper nature and density to resist the intense heat of the metal, but every suitable means must be employed to resist the constant pressure exerted Avhilst it remains in a fluid state. How to meet all these con- ditions and maintain a mould surface that shall be free from errors likely to produce faults in the resultant casting taxes the moulder severely when the material is not in all respects what it should be, and many are the contrivances invented to counteract or neutralize evils that are known to exist, as well as to provide against possible contingen- cies. The nature and quality of sands changing with each locality renders it almost impossible to formulate absolute rules for ramming which shall be equally applicable at all places; it remains, therefore, with the intelligent moulder to observe well the kinds of sand he must work with, and regulate his ramming accordingly, remembering that with the finer grades there is always a possibility of ramming the mass to a consistency that will effectually prevent the escape of gases which form throughout the mould's sur- face when the metal enters therein ; especially is this to be observed when the sand is of a clayey nature. See Green- sand Moulding; Facing-sand; etc. Ramming dry-sand moulds is not by any means as im- portant as green sand, it only being required in this case to pack the sand firmly and evenly to the mould face, and of sufficient density elsewhere to permit of free handling and resist pressure from within. If the facing-sand be comparatively free from gas-producing substances, and the moulds are thoroughly dried, there is no necessity what- ever for venting ordinary dry-sand moulds, there being no steam to lead away, as in the case of green-sand moulds. For this reason unskilled labor may, with some direction, Ram's-horn. 333 Rapping-plate. be employed for ramming very many of the moulds made in dry-sand. See Dry-sand Moulding; Dry-sand Facing; etc. Pit ramming is simply the process of packing the space between the mould and the pit wall with sand to prevent the pressure exerted within the mould from forcing out the walls; in other words, the pit is made to answer the purpose of confining the whole mould, just as a flask does. A knowledge of the laws of pressure in moulds is very helpful to the moulder in this instance, because, knowing that pressure is greatest at the bottom it is at that point where the hardest ramming must occur, and every course of ramming may be made proportionately less dense as the top is reached, and consequently much valuable time saved in the operation. See Tramping; Pit; Venting; Butt-rammer; Pegging-rammer. Ram's-horn. — A hook used for passing loads from one crane to another. See Double-hook. Rapping-bar. — A pointed bar of iron with which to jar the pattern in order to make it leave the sand more readily. See Loosening-bar. Rapping-plate. — An iron plate inserted in a pat- tern at such places as it may be desired to effect a jarring or loosening of the same. Ordinarily these plates are sunk down even with the surface, and fastened with common wood screws. For light patterns easy to loosen these answer well enough; but in larger ones it becomes neces- sary to make the plates strong, with more surface, and secure them by bolts to a similar one on the opposite side of the pattern. By this means the nuts will always bring both plates close to the pattern, and thus obviate the unpleasantness which is sure to follow if the common Rasp. 334 Ratio of Fuel to Iron screw-plates are used. Another advantage the bolted plates offer is that the upper plate may have a threaded hole in which to insert an iron screw for drawing out the pattern. These are often called screw-plates. They are much better than driving spikes into the pattern. See LOOSENLtfG-BAR. Rasp. — The rasp differs from the file in that the teeth protrude separately, thus making a surface much more suitable for filing cores than does the chisel-cut teeth of an ordinary file. Ratio of Fuel to Iron. — Ratio of fuel to iron means the proportion of fuel burned to melt a given quantity of iron, as 1 to 5, or 1 to 12, — indicating that five pounds of iron is melted with an expenditure of one pound of fuel in the first instance, the latter indicating that twelve pounds is the quantity of iron melted with the same amount of fuel. Any attempt to formulate absolute rules to be observed by the cupola-man at all foundries alike must assuredly result in extreme disappointment, as nearly every place has its own special needs and requirements, which can be successfully met only by intelligent obser- vation and persistent effort on the part of the cupola-man or his superiors. For this reason comparisons relating to the economics of melting iron at different foundries are of no real value, disappointment and loss being sure to attend any attempt to appropriate the systems of others, which may in all probability have been founded on experiences diametrically opposite to our own. Any conceit we may have indulged in because of our ability to melt iron at the ratio of 1 to 10 for the line of castings we produce must be forever dissipated when we discover that the exceedingly low temperature of such iron would render it utterly valueless for the light castings Ratio of Fuel to Iron. 335 Ratio of Fuel to Iron. produced by our neighbor, who for this reason must necessarily use more fuel to meet his case successfully. The foundry melting a standard gray pig with first-class scrap should undoubtedly melt its iron down with greater regularity and with much less fuel than where perhaps unwieldy and promiscuous scrap with a slight admixture of pig is the iron charged. Quality of fuel affects results perhaps more than any- thing else; if poor, a greater amount must be used to obtain the requisite quantity of carbon. This, of course, increases the bulk between charges and requires extra time for its consumption; while the superfluous, impure substances, as slate, etc., yield a viscous slag, which interferes in no small degree with the regular process of melting, retarding it always. Even when all other things are favorable, the pressure of blast and care bestowed on apparatus will al- ways exert an influence for better or worse proportionate to the amount of intelligence brought to bear upon such important details. Leaky pipes and fitful and uncertain blast mean extra fuel and delay in melting operations. Construction of the cupola and its locatiou, with refer- ence to adverse wind currents and draught, is sufficient in some instances to mar effectually the best efforts of the cupola-man, interfering, as it does, with the first efforts to ignite the fire, and thus precluding all possibility Qi an evenly-burned stock— a forerunner sometimes of endless subsequent vexations and delays. The unfairness of com- paring the performance of cupolas laboring under these and kindred disadvantages with others of faultless con- struction and suitable location will be apparent. The wastefulness attending melting small heats in cupo- las designed for more extended operations is made plain by the following: Suppose a 44-inch cupola is employed for a heat of 12,060 pounds, the amount of fuel used, including bed, being 2140 pounds: the ratio would be 1 fuel to 5.63 Ratio of Fuel to Iron. 336 Ratio of Fuel to Iron. iron melted. Now increase the heat by six additional charges of iron to 37,440 pounds, maintaining the same ratio of fuel between the charges as before: this gives 4960 pounds total fuel used, and the ratio is now 1 to 7.53. These are only a few of the things to be considered when comparisons are made. It may be a subject for remark that such a firm is melt- ing iron with a much lower ratio of fuel to iron than another, and much annoyance is caused by this undisputed fact; but all this would perhaps be modified if careful investigation were instituted. Possibly this distinguished firm is melting carefully selected irons of the same mixture every day without deviation all the year round — a state of things eminently conducive to perfect practice; while those with whom they have been compared are, owing to the numerous and sometimes unpleasant changes in the nature and quality of the castings made, compelled to change their mixtures often, and more than once during the same heat sometimes. Means for rapid transit, or close proximity of the cupola to the moulds which are to be poured, will favor metal of a low temperature being melted, thus allowing a diminished ratio of fuel. But if facilities for conveying are limited and the moulds far removed, it is incumbent that hotter metal be provided to compensate for the extra time occu- pied in handling. This increased temperature can only be obtained by increasing the ratio of fuel. The preceding represents in some measure a few of the reasons for the high ratio of fuel to iron as necessitated in foundries which are unfavorably circumstanced as de- scribed; still, without doubt, there is considerable waste of fuel almost everywhere, that might be remedied if rigid investigation by qualified practitioners were established. Cupolas now yielding unsatisfactory results at many places might be changed to the best of their kind if those Ratio of Fuel to Iron. 337 Ratio of Fuel to Iron. who work them were compelled to learn the importance of placing every charge of fuel and iron in the cupola systematically and precise. This, of course, can only be done by the cupola-man who knows that in order to retain the heat within the cupola and not have it wasted up the stack more than ordinary attention must be paid to a favorable disposition of the materials charged, and, further, that to insure regularity in both speed and fluidity every pound of such material should be carefully weighed. By this means alone can he pursue a course of safe experi- mental practice, the results of which if carefully noted will furnish him with all the knowledge essential for supplying metal from his cupola at all times the exact temperature demanded, and without fear of disappointment. No reli- ance can be placed on any method of melting that does not include a correct proportioning of the fuel and iron at every charge. Besides this, it is incumbent on the cupola-man that he carefully observe the action of his tuyeres, changing the form from time to time, raising or lowering them, increas- ing or diminishing their number; or, if the tuyeres be continuous, trying the effect of a gradual contraction <~r expansion from their original width. Expansion of tuyere area with no increase in wind-pressure will soften the blast while contracting them will have the effect of creating a cutting blast if original wind-pressure is maintained. By observing results from these several changes, as well as increasing and decreasing wind-pressure in the blast-pipes, he may arrive at the very best practice possible for the cupola he manages, and the ratio of fuel may be reduced intelligently to the lowest possible rate consistent with the actual requirements of the foundry. Much, if not all, of the annoyance and loss consequent on melting inferior irons, which include large quantities of the meanest machinery, stove-plate scrap, etc., in cupolas Rattler. 338 Rectangular Cupola. of moderate capacity may be obviated by a persistent adoption of the fluxing method. Usually, when large pro- portions of such iron are melted in the cupolas above mentioned, the heat is short-lived and unsatisfactory; but if a suitable flux is used, the dirt in the iron intimately associates with it and forms a thin liquid slag, which, by means of a slag-hole placed a short distance below the tuyeres, can be run off at pleasure, and so continue the melting uninterruptedly for an indefinite space of time. See Cupola. Rattler. — A name given in some localities to the tumbling-barrels used for cleaning castings. See Tum- BLLNG-BARRELS. Rawhide Hammers are light mallets made entirely of hide (except the handle), and are especially valuable where light, thin castings are made. See Mallet. Rectangle. — A right-angled parallelogram; a four- sided figure having right angles only. Rectangular Cupola. — This style of cupola is not often met with at this day, the common round or oval one having taken its place almost everywhere. The sides of these cupolas were usually composed of four cast-iron plates which rested vertically on a solid foundation of stone or brick, and were held together by bolts at the corners. The widest plates were about one third longer than the others, and it is one of these wide plates which faces the foundry, being provided with a breast-hole at the bottom, which answers for tap-hole, and furnishes means for rak- ing out when done melting. In order that the greatest quantity of metal possible might be gathered on the bot- tom before a tap was made, it was customary to pierce each side with several holes about 8 inches apart, one above the Red Brass. 339 Red Lead. other, so that by means of a flexible hose or a sliding pipe the tuyeres might be raised as the metal accumulated, the blast being suspended during the process of raising the pipe and making the lower holes good with suitable plugs. The height of these cupolas was about three times the length of the long side, and the hole was lined with ordi- nary square fire-brick, the bottom being made with sand as now. See Cupola; Bkeast-hole. Red Brass. — The common red brass called red tom- bac, used for cheap jewelry, is composed of copper 11, zinc 1. Red sheet brass is copper 11, zinc 2. A good red brass for turning: copper 24, zinc 5, lead 8. Eed brass for fine castings: copper 24, zinc 5, bismuth 1, the latter to be added just before pouring. See Tombac. Red Hematite. — A very important class of iron ores, which vary in color from a deep-bright red to gray. Its streak and powder are a blood-red. Specular iron is a variety of hematite often found in beautifully colored crystals. Clay ironstone consists of hematite mixed with certain proportions of clay and other impurities. The common red chalk is a variety of hematite mixed with clay. It is a valuable iron ore, and yields when pure about 70 per cent of metallic iron. Its powder is used as a color- ing material for paints and for polishing metals. The variety called "puddler's-mine," being of a soft, compact nature, is used for making and repairing the bottoms of puddling-furnaces; when used for this purpose it is called " ore " by the puddlers. See Ores; Puddles-g-fuk^ace. Red Lead. — When metallic lead is exposed at a red heat to a current of air, the lead rapidly combines with oxygen, and the oxide so produced fuses. It forms, on cooling, crystalline masses of a greenish-yellow color; this Red Ochre. 340 Reduction of Metals constitutes the litharge of commerce. Eed lead is pro- duced when the lead is oxidized so that the oxide formed shall not be fused, and when the metal is all converted into the yellow powder, increasing the heat to incipient redness. Oxygen continues to be absorbed until one third of the metal is converted into peroxide ; this is the pure red lead. See Lead; Lithakge. Red Ochre.— One of the soft, earthy varieties of red- hematite iron ore. See Red-hematite. Red-short. — Iron or steel is by the millmen termed red-short when it shows an impaired malleability at a red heat. See Cold-short. Reel Tombac— See Red Brass. Reduction of Metals. — The circumstances under which the metals are found in nature are exceedingly diverse, some being found in a native state or alloyed with other metals, as gold, silver, bismuth, and some others; some combined with arsenic, as cobalt, nickel, etc.; but by far the most abundant forms in which the metals are to be found are combinations with oxygen and sulphur. There are few of the metals that do not exist naturally in the state of oxides, which are either free or else combined with acids, forming salts. The majority of the metals exist also in nature combined with sulphur. The native compounds of the metals are termed ores, and the metal is said to be mineralized by the substance to which it is united. The several processes of reduction, or extracting the metal, must of course be regulated by the composition of the ores in which it is contained. When the metal exists only in an oxidized condition, the ore is heated in contact with the fuel, by which carbon is supplied in Reeking Ingot-moulds. 341 Reeking Ingot-moulds. abundance for its reduction. The carbon combines with the oxygen and the metal is set free. Should the mineral- izing substance be anything else than oxygen, carbon, no matter how intense the heat, could produce no effect upon the ore. Native sulphurets, etc., for this reason are not acted upon by carbon; and in order to reduce the metal from its sulphuret, the ores of lead, zinc, copper, etc., are first reduced to powder and heated to redness in a current of air by the oxygen, of which the sulphur is converted into sulphurous and sulphuric acid, while the metal is ox- idized. This process is termed calcination. A great part of the sulphuric acid formed is carried off with the current of air, and the remaining product is a sulphate of the metal. When the salt so formed is deoxidized by contact with the fuel, the excess of oxide, abandoning its oxygen, yields an equivalent quantity of metal, which, however, would be impure and of inferior quality, having dissolved a portion of the sulphuret reproduced by the reduction of the sulphur from the sulphuric acid. It is therefore neces- sary to get rid of that residual portion of the sulphuric acid before the deoxidizing process commences, and this is effected by mixing up a quantity of lime with the calcined mass. The lime decomposes the metallic sulphate, com- bines with the sulphuric acid, and sets the oxide free; and when the deoxidizing flames of the reverberatory furnace pass over the calcined mass, the metallic oxide being re- duced yields a pure metal, while the sulphate of lime, by losing its oxygen, is brought to the state of sulphuret of calcium, and remains a slag upon the surface. For the processes by which iron is reduced, see Cast Iron; Cal- cination; etc. Reeking Ingot-moulds. — To prevent cast-steel ingots from sticking to the cast-iron moulds, it is custom- ary, at some steel-works, to place the halves of the moulds defining Metals. 342 Refining Metals. with their faces down, upon a suitably provided support, which permits the burning coal-tar underneath them to deposit a coating of soot upon their surfaces. The process is termed reeking. See Ingot-moulds; Bunnlng-steel Ingots. Refilling Metals. — The art of purifying a metal from dross, or separating it from metallic alloys. More or less impurities remain after the common methods of reduction have been employed, which can only be eliminated by subse- quent refining. Copper, for instance, usually contains small quantities of antimony, iron, tin, etc., after reduction in the reverberatory furnace used for this purpose. By re- melting in the refining-furnace and exposing the metal to the oxidizing influence of the air, these foreign metals oxidize and are converted to slag, which is skimmed off as it rises in the crucible. This operation subjects the copper to oxidization also, but the copper oxide is reduced again by adding coal to the surface and stirring the metal with a green-wood pole. The pole emits its gases forcibly, and creates a violent ebullition which exposes every portion to the reducing action of the coal, by which means the oxide of copper is deprived of its oxygen and the copper is made pure. Tin and lead are treated after the same manner ordinarily, but special processes are followed for the sepa- ration of silver from the latter metal. Gold is refined by first dissolving the metal in aqua regia (see Aqua Eegia), after which the silver, etc., with which it is usually alloyed may be precipitated by chemicals having no action on the solution of gold. Salt of iron is then employed to precipi- tate the gold in a fine powder, which is then melted and cast, the product being pure gold. Eefined silver is ob- tained by dissolving the metal in nitric acid, and, after filtering the solution, precipitating it with comnion salt as a chloride of silver, which, after being mixed with sul- Reflecting-glass. 343 Regenerative Furnace. phuric acid, is acted upon by bars of zinc, by which means chloride of zinc is formed and the silver again resumes the metallic state. See Reducing Metals ; Separating Metals from their Alloys. For refining iron, see Mal- leable Iron; Finery-furnace ; etc. Reflecting-glass. — A small mirror confined within a frame, having a small handle. These glasses are supplied by the foundry supply dealers, and are extremely useful for directing light down into the deep cavities of a mould. Reflector Metal. — Very good reflectors are made by dipping the round end of a glass vessel (which has been previously ground) into an alloy composed of tin 49, lead 19. A thin coating of the alloy, remarkably brilliant in ap- pearance, will adhere to the ground surface. See Diamond and Brilliant Imitations. Refractory Materials. — All such substances as melt only at the highest temperatures that can be produced are classed as refractory. Amongst these are included some natural rocks, as sandstones, quartzites, granites, etc.; but it is not customary to use these alone for metallurgical purposes, on account of their liability to split apart at high temperatures. The principal substances employed, in vary- ing proportions, as mixtures for furnace-linings, crucibles, retorts, fire-bricks, etc., are silica, magnesia, bauxite, steatite, clays, carbon, gannister, coke, etc. Nearly all clays require to be mixed with other materials, to counteract the ten- dency to shrink and crack. If it were not for these admix- tures, the bricks made from some of the clays would soften and melt away when subjected to very high temperatures. A description of the materials mentioned, and numerous other refractory substances, will be found at their respective places. Reheating-furnace. 344 Repairing the Cupola. Regenerative Furnace. — The Siemens regener- ative furnace is composed of three divisions, including the producers, where the crude gas is generated; the regenera- tors, chambers containing a network of fire-brick passages through which the heated gases and flame may circulate and the heat be stored as they escape from the furnace, to be again mixed with the gases from the producer and the air as they pass through the regenerator to the furnace hearth; and the furnace itself, which is the third division. By this arrangement the outgoing heated volatile products heat the mass'of bricks in the chamber, and this again heats the incoming air and gas supplied to the furnace. See Siemens-Martin Steel. Reheating-furnace. — These furnaces, although used for various purposes, are all of the reverberatory type, similar to a puddling-furnace. They are used for heating wrought-iron piles, blooms, billets, etc., and the ingots, slabs, blooms, etc., of steel, to the temperature suitable for hammering or rolling. They are sometimes called balling - furnaces. See Reverberatory Furnace. Relievo, or Rilievo, is a term applied to works in sculpture and the fine arts where figures are made to pro- ject from the ground or body on which they are formed and to which they remain attached. It is Basso-rilievo when the figures project only slightly from the ground, Mezzo-rilievo when they stand out half their natural proportions, and Alto-rilievo, or high relief, when the figures are so prominent from the ground that merely a small part of them remains attached. See Intaglio. Repairing the Cupola. — The first duty of the cupola-man, after the refuse of the previous day has been carefully picked for whatever iron and unburn t fuel may be found, is to chip out the cinder and scoria from the in- Repairing the Cupola. 345 Repairing the Cupola. side of his cupola and ascertain what damage has been done to the walls. Now, good tools for this operations are an absolute necessity, as the more pounding required for the loosening of this adhering dirt, the more will the brick lin- ing be loosened — a result to be avoided if possible. For this operation the cupola-man should be supplied with an ade- quate set of steel-pointed chisel-bars, large and small, and these, along with steel pick-hammers of suitable dimensions, should be kept sharp and of proper temper. When tools of this class are supplied -there will be no difficulty in chipping out in such a way as to jar the bricks but little, and leave the surface clean and ready for the daubing, and in much less time than it takes to do it in the slipshod way it must inevitably be done where perhaps only a sledge-hammer is used. The chief object in repairing is to maintain as near as possible the original shape of the cupola. Except at the melting zone, just above the tuyeres, this may be accom- plished fairly well ; but at that point there will be, owing to the intense heat and force of the blast a decided tendency of the bricks to waste away; and it is just here where the judgment and skill of the cupola-man is put to the test, as by proper management a lining may be preserved almost indefinitely. By careful observation it may be seen which parts are being acted upon the most. Follow up at these parts with thin coats of daubing (see Daubikg), and use no more than will adhere firmly to the wall, without fear of its being prematurely loosened by the intense heat. The bad effects from using too much daubing of any kind may be understood when we consider that most of this dry- ing must take place immediately the heat is intensified by the admission of the blast ; the front of the patching dries at once, and the rapidly formed steam should find an outlet at the brickwork behind; failing this it naturally forces off the daubing, which falls over on the stock, the result being Reservoir. 346 Itesin. that the regular action of the cupola is interfered with to the extent of changing the direction of the blast and pre- venting the iron as it melts from falling direct to the bot- tom ; by this means some iron finds its way into the tuyeres, some lodges around them and solidifies, ultimately choking the orifice altogether. Thin daubing, well rubbed on, will never fall away if made of the correct ingredients. When it has been thought necessary to insert new bricks at parts, as well as to rub on more daubing than usual, light up a little earlier in order to dry it out with a more gentle heat. Better a little extra expense in fuel than run the risk of a bad heat. See Daubing; Cupola. Reservoir. — Dams constructed for the purpose of gathering a large quantity of metal are sometimes called reservoirs; as also are runner-basins when constructed of extraordinary dimensions to receive the molten metal from very large pouring-ladles. See Dams; Basin; Gather- ing-metal. Resin is a solid, inflammable substance, of vegetable origin, being obtained from various trees by making inci- sions in their bark and allowing the liquid to exude. This liquid is the essential oil of the plant, and holds the resin in solution. Resins are insoluble in water, but alcohol dis- solves them ; they are of an inflammable nature, and yield a dense, sooty smoke when burning. Mastic, sandarac, lac, copal, etc., are some of the resins from which varnishes are made, all of which are readily dissolved in such solvents as spirits of wine, oil of turpentine, methylated spirit, and wood naphtha. The evaporation of the spirit, after these varnishes have been applied, leaves a hard layer of the resin on the surface of the object treated. The common resin, or rosin, of commerce is obtained from the various species of pine. Gum-resins are the solidified milky exudations of plants. Restoring Burnt Steel. 34y Retort. They consist of resin, essential oils, and a gummy substance peculiar to the plant. The ammoniacum, assafoetida, aloes, myrrh, gamboge, etc., belong to this class; they are all soluble in rectified alcohol, and are valuable as medicinal agents principally. Elastic gums, as caoutchouc or india- rubber and gutta-percha, are valuable in the arts and manu- factures; the former consists of a thick milky juice of certain trees growiug in tropical countries, and is a mixture of several hydrocarbons with turpentine oil. When pure it is nearly white. It will soften in boiling water, but nob dissolve; it is also insoluble in alcohol, but readily dissolves in coal naphtha, rectified oil of turpentine, pure ether, chloroform, or carbonic disulphide. Caoutchouc is ren- dered more permanently elastic by combining with it certain proportions of sulphur. It is then called vulcanized india- rubber. See Gutta-percha; India-rubber. Restoring Burnt Steel. — It is said that burnt steel may be restored by making a powder composed of 8 oz. sal-ammoniac, 3 oz. prussiate of potash, 3 oz. borax, 1J lbs. resiu, 2 oz. blue clay, ^ pint alcohol, and J pint of water. These ingredients are to simmer over a fire until dried to a powder; the burnt steel may then be reheated, dipped in the powder, and hammered. See Tempering. Retort. — A vessel employed for the purpose of decom- posing bodies by the aid of heat, the process being termed distillation. Those used in the chemist's laboratory are a kind of globular bottle, with a long neck bent at an angle of about sixty degrees with the belly of the retort; they are made of glass, porcelain, platinum, earthenware, etc., accord- ing to the substances to be acted upon. The spirit-lamp, gas, or sand-bath is usually employed for heating glass retorts, but when higher temperatures are required it is necessary to use those made of platinum or earthenware. Return-facing. 348 Reverberatory Furnace. Single retorts for distilling coal-gas are usually made D-shaped, about 21 X 14 inches X 9 feet, closed at one end, and provided with a mouthpiece at the other. Through retorts are made twice this length, with both ends open, but having mouthpieces which close them dur- ing the process of distillation. Formerly these retorts were all made of cast iron, but they are fast being super- seded by those made of fire-clay, which admit of higher temperatures and last much longer. The distillation of mercury from cinnabar is conducted in retorts similar to those used for making illuminating-gas. See Distilla- tion ; Mercury ; Tar. Return- facing". — The use of return-facing is con- fined principally to foundries manufacturing thin, light castings, as stoves, etc.; where, having no coal mixed through the sand, means must be provided, not only to scale the casting clean, but leave the color uniform through- out. To effect this the raw sand surfaces of the moulds are first treated to a dusting of bolted hydraulic cement or German clay (a cheap substitute for heavy carbon-facing) to fill the pores of the sand, then a light dusting of heavy facing, and, lastly, the return-facing in just sufficient quantity to permit the pattern, when returned, to leave its impression sharp and smooth without sticking. The carbonized preparations of return-facings supplied by the dealers are, as a rule, preferable to the light charcoal-fac- ings usually employed for this purpose, as they neither run before the metal nor adhere to the pattern as much as charcoal is liable to. See Printing; Facing. Reverberatory Furnace. — Democritus is sup- posed to have invented the reverberatory furnace long before the birth of Christ. These furnaces are constructed so that the materials (o be treated are operated upon by the Keverse-mould. 349 Reverse-mould. heat of the flame without their coming into direct contact with the fuel. The reverberatory furnace is commonly employed for metallurgic purposes, and is especially ad- vantageous for extracting metals from their ores, and for the numerous processes connected with the manufacture of malleable iron, steel, melting cast-iron, brass, etc. The furnace consists usually of a rectangular fire-brick construction about twelve feet long, six feet wide, and from five to six feet in height, contained within iron plates which are bound together by an arrangement of buckstays and bolts. The fireplace at one end is separated from the bed proper by a fire-bridge, and an arched roof is made to dip towards the chimney at the opposite end of the furnace; by this means the flame is caused to play with considerable force over the fire-bridge and against the roof, to be again reflected or reverberated downwards upon whatever has been placed upon the bed behind the bridge. A charging-hole is provided on the side opposite to the fireplace for fuel, and a larger one for charging the materials to be operated upon is also provided convenient to the bed, some distance from its bottom. The latter hole is opened and closed by a vertically sliding door, the inner side of which is lined with fire-bricks, and is controlled by means of a lever; but the hole at the fireplace is simply stopped with coal. A hole at the bottom of the chimney allows the cinder produced during the puddling process to escape as it flows down from the bed over a bridge built in the flue. Other smaller holes are provided to permit a free use of iron bars for polling, etc., during the operations. Except in a few minor particulars, the air or reverberatory furnace for melting metals answers to the above description. See Puddling-furnace; Malleable Iron; Polling. Reverse-mould is sometimes termed a dummy-block, and consists of forming in loam or sand, by means of the Revolving Furnace. 350 Revolving Furnace. spindle-centre or otherwise, any model, the impression of which it is desired to copy in the cope or other containing part of the mould. This means is employed when it is desired to obtain a casting such as a bevel or spur-wheel, etc., without incurring the expense of supplying a whole pattern. For example, if it was required to mould a bevel-wheel after this manner, the first operation would be to strike a reverse-mould or " dummy " answering to the permanent joint at the points of the teeth, and from thence over the entire back of the wheel exact to the wheel's form and dimensions on that side. This would give a true model of the back, the impression of which being obtained in the cope, it only remains to first destroy the "dummy "and then sweep out the lower surface direct, commencing at the points of the teeth again, as for the cope impression. After the teeth are rammed from the segment supplied, and the arm-cores have been placed, the cope, as previ- ously obtained from the reverse-mould, is returned. The joint is the original one from which the cope im- pression was taken; if tops of teeth and arm-cores are made to correspond with the original model obtained, the mould will close as accurately as when a full pattern is employed. A thicknessed pan-core serves as a reverse- mould for the cope. See Dummy-block; Kettle; Back- ing-out. Revolving Furnace. — Kevolving furnaces consist of horizontal wrought-iron cylinders lined with fire-brick, one end of which communicates with a fireplace and the other to a chimney, which, being revolved on rollers as the flame passes through the interior, permits a thorough mix- ing of the mass and exposes every portion of the material to the action of the heat. This description of furnace is princi- pally employed for roasting, desulphurizing, and chloridiz- Revolving Oven. 351 Rice-glue Statuary. ing ores. The Danks and other furnaces of a rotary kind are used for puddling purposes, and consist of the fixed fire- place and bridge, but, iustead of the regular bed, a re- volving hearth through which the flames are made to pass to the chimney is used for melting the metal. The molten metal, being spread over the interior by the rotary action of the chamber, is brought in contact with the lining, which, being composed of iron ore, acts in conjunction with the oxygen of the furnace gases to oxidize the carbon and silicon contained in the iron. The spongy mass of malle- able iron produced is readily lifted out and conveyed to the squeezers after the movable end has been taken away for this purpose. See Puddling-furnace ; Malleable Iron. Revolving Oven. — See Rotary Oven. Revolving Sand-screen.— See Riddles. Rhodium is one of the rare metals of the platinum group. Excepting iridium, it is the most infusible metal, very hard and brittle, and of a whitish color. When this metal is alloyed with copper, bismuth, or platinum, it may be dissolved with them in aqua regia, but it is insoluble in acids when pure. Owing to its unalterable nature, rhodium has been extensively used to form the nibs of metallic pens and other similar purposes. See Platinum. Rice-glue Statuary.— Statuary composed of rice- glue or paste is a very common production of the Japanese, who mix the flour with cold water and then boil to the consistency of paste, adding whatever color is desired. This paste, when stiffened by a further addition of flour to the consistency of clay, is then modelled and allowed to Riddles. 352 Riddles. dry, when it assumes the appearance of marble, and will take a beautiful polish. See Statuary-founding ; Mod- elling; Plaster-casts. Riddles. — There is no tool that a moulder uses more constantly than a riddle, and it "behooves the proprietor to buy the very best riddle that he can find. The reason is obvious. A cheap riddle is put together in the quickest manner possible, the wood used in the rim is of the com- monest kind, and much too light for the purpose. The wire is bought by the pound, therefore the lighter wire is put in the riddle to lessen the cost; the wire for, say, a No. 6 extra-heavy riddle is used for a No. 4 cheap riddle, etc.; then the cloth is cut so sparingly that it does not wrap upon the rim far enough to hold for any length of time. Nine times out of ten one or the other (cloth or rim) gives way before the light wire wears out. The brass riddle is undoubtedly the best for use on the foundry-floor: it never rusts; the wires are always clean of sand, allowing the use of the full mesh. A steel-wire riddle will rust; and the galvanized riddle having wires of a rough surface, the sand will cling to them, filling up the meshes, thereby taking longer time to riddle the sand. For iron, coal, or cinder riddles the heavy crimped iron-wire riddle is the best. Those made especially for siftino- iron out of sand and other similar uses should be made one-inch mesh, from good strong iron wire. Parting- sand riddles or sieves, any diameter, with or without cross- bars, can be obtained from the dealers, and special sizes of heavy steel sand-screens may be had from the same parties, as well as an endless variety of power and portable sand- sifting machines. The revolving riddle or screen is a remarkable improvement on existing methods for sifting and mixing sand. See Sand-screen, Rigging. 353 Roasting Ores. Rigging. — "Rigging" and "tackle" are synonymous terms in the foundry, meaning the furnishings or appa- ratus provided for the construction of moulds. Founda- tion-plate, rings, plates, beams, slings, bolts, etc., constitute a large proportion of the rigging for loam-work; while the flasks, cheeks, drawback-plates, clamps, bolts, beams, etc., represent the rigging almost always required for any im- portant mould in green or dry sand. Ring. — A word of general application to all circular contrivances for moulding purposes, but invariably recog- nized as meaning the cast-iron ring which encircles the seating of a loam-mould, upon which ring the cope is built, and by means of which it is passed to the oven and from thence back to the pit for final closing over the mould. See Cope-ring; Cope; Loam-moulding; Building-king. Ring-bolt.— See Eye-bolt. Riser. — A gate set on the top or leading from the side of a casting, either to indicate when the mould is filled with metal or to be used as a means for introducing fresh supplies of hot fluid metal to make good the deficiency caused by shrinkage. In the latter instance the riser is often called a cut-off or flow-gate; in the former the terms "rising-head" or "feeding-head" are commonly used. See Cut-oee; Flow-gate; Feeding-head; Feeding-rod. Rising-head.— See Eiser. Roasting Ores. — Ores are roasted in order to sepa- rate the volatile bodies from those which are more fixed, and is generally performed in a current of air so as to effect simultaneous oxidation. See Ores; Weathering Ores. Rock. 354 Rod-iron. Rock. — A stony substance which forms a great part of the earth's crust, sometimes loose and friable-like sand, and again compact, like granite and limestone. Eocks are classified as primitive, rocks of transition, stratified, allu- vial depositions, and volcanic, and modifications resulting from the conditions to which they have been exposed. Rock-crusher. — A mill for breaking and crushing rocks; it may also be used for pulverizing quartz, gold or silver ores, plumbago, Portland cement, rosin, foundry facings, etc. Some of the machines used for this purpose will work either wet or dry, and deliver a finished product. Their capacity is 3 to 4 tons per hour on phosphate rock, 1\ to 2 tons per hour on Portland cement, quartz, or ores, depending on hardness of material to be pulverized and fineness of product, and will grind from 30 to 250 mesh with equal facility. See Sand-pulverizer. Rock-crystal. — A common name for the finest and purest quartz or transparent, crystallized silica. The pebble lenses for spectacles, etc., are made from rock-crystal. See Quartz; Silica. Rock-oil. — See Petroleum. Rock-sand. — The name given to all moulding-sands obtained by pulverizing the rock; their value is regulated according to the durability they possess. The new red- sandstone is preferable for this purpose, as its nature is refractory, and it may by artificial means be made to an- swer nearly every description of mould. See Facing-sand ; Core-sand; etc. Rod-iron. — The common round and square rolled iron, used in the foundry for making feeding-rods, gaggers, lifters, core-irons, mould-stiffeners, etc. Rolled Glass. 355 Rolls. Rolle€l Glass. — An inferior kind of plate-glass about one inch in thickness is now made for common purposes by first obtaining the requisite quantity of molten glass in a suitable clipper and then emptying it on a casting-table, on the edges of which are the thickness strips, on which the roller travels as it spreads the glass over the surface. Rolls are cylindrical rollers of steel or cast iron, which when mounted in the housings so that they cannot recede from each other, and provided with suitable gearing for causing them to revolve, are employed for reducing metals to plates, rails, bars, etc. Steel is fast taking the place of cast iron for the manufacture of rolls. Cast-iron rolls are made to present a hard steely surface by casting the plain body in a smooth cast-iron chill-mould, the ends of the casting being formed in the sand or loam as for soft rolls. Common soft rolls may be swept horizontally, as described in " The Iron Founder," p. 274; also vertically, as an ordinary loam-mould; or they may be moulded from patterns in either of the positions mentioned — the only difference being that the pattern for horizontal moulding must be equally divided lengthwise, whilst the one for ver- tical would consist of a separate upper and lower neck and body patterns, with drag, check, and cope parts to match. The latter represents the method to be employed for chilled rolls, excepting that instead of the body-pattern and cheek- part, the chill is here substituted, consisting of a smooth cast-iron mould of sufficient thickness to absorb the heat rapidly, and thus produce a hard steely surface by prevent- ing any separation of the chemically combined carbon into graphite at that part. Whatever mode of moulding is adopted, it is all impor- tant that the metal be introduced at the lower neck, away from any direct action on the chill; otherwise the chill may be irretrievably damaged, and, if the stream be caused to Rolling-mill. 356 Root's Positive Blower. flow in a tangential direction, the molten mass within will be made to rotate rapidly, and thus collect all the lighter scum in the centre, which, as the mould is filled, mounts upward, to be finally ejected into the open riser above. See Eiser. Rolling-mill is where the balls from the puddling- fnrnace, after being operated upon by the squeezer, are, by means of successive passes through the various rolls, re- duced in bulk, with a corresponding increase in length, until the desired bars or sheets are produced. See Mal- leable Irok; Train. Rolling-over. — A term applied to the method of ob- taining bottom or lower portions of mould by first ramming the pattern within the drag or nowel part, and then revers- ing the position of the flask, by means proportionate to its size and weight. Ordinarily the pattern is placed face down on the follow-board or match-plate, over which is set the nowel or drag. The pattern, being first covered with facing- sand, is then subjected to a process of ramming until the flask is filled with sand, when, if the flask be an open one, a board or plate is laid over and clamped firmly to the fol- low-board, but should there be cross-bars in the flask, the plate is dispensed with. After clamping, the whole is rolled over, and is ready for subsequent operations. See Follow- board; Match-plate. Roman Cement.— A beautiful cement, improperly called Roman, is made as follows: Calcine 3 parts of ordinary clay, and mix it with 2 parts lime; grind it to powder, and calcine again. Root's Positive Blower.— The internal operating parts of this positive blower consist of two revolvers, each Rope. 357 Hope. of which is operative. Externally the blower consists of the case, four journals and journal-boxes, four cut gears, an oil-tight housing, and two driving-pulleys. This blower operates by a regular displacement of air at each revolution, whether it runs fast or slow. When the air enters the case at the opening for induction, and is closed in by the wings of the revolvers, it is absolutely confined, and positively forced forward until brought to the eduction- pipe, where it must be discharged, or the machine stop, if perfectly tight, as there can be no backward escapement of the air after it once enters the case, the contact being kept up at all times in the centre of the blower between the pistons or revolvers, thus preventing any escape of the air in that direction. See Blower; Blast. Rope. — Any cord over an inch in diameter is called a rope. Ropes are principally made of vegetable fibre, the chief of which is hemp. Coir rope is made from the fibrous husk of the cocoanut; manilla rope from the fibres of a species of banana; in addition to which cotton and TABLE OF Dimensions and Weights of Short-linked Chains and Ropes, and Proof of the Chain in Tons. (Haswell.) *8 3 o © C c« 5W o • a"! .^5 2 *o3 O c3 &0Q 3 o "- 1 S-l • Inches. Lbs. Tons. Inches. Lbs. Inches. Lbs. Tons. Inches. Lbs. A 6 .75 u 1.5 H 28 6.5 7 10.5 1 8.5 1.5 3\ 2.5 f 32 7.75 n 12 11 2.5 4 3.75 it 36 9.25 H 15 14 3.5 4f 5 7 1" 44 10.75 9 17.5 18 4.5 5i 7 15 T6 50 12.5 9i 19.5 1 24 5.25 6i 8.7 1 56 14 10 22 Note.— The ropes of the sizes given in the table are considered to be of equal strength with the chains. Rope-slings. 358 Rosin-cores. other similar substances enter largely into the business of rope-making. Wire rope, both iron and steel, is now ex- tensively employed both on shipboard and on land. The machines invented by Mr. John Good, Brooklyn, N. Y., and others have made it possible to so manufacture ropes that their strength may be measured with the greatest exactness. Large cable-laid ropes consist of three large strands, each made up of three smaller strands. Hawser-laid rope has only three strands, each containing a sufficient number of yarns to make up the required thick- ness. Rope-slings. — A very handy and useful substitute for heavy iron slings, when the flasks to be turned over are not too ponderous. Made as a single strand, with eyes at each end, or by splicing both ends of the rope together, they are infinitely superior to chains where large wood flasks are in constant service. The dealers supply these slings, leather-bound at theloops and middle, as desired. See Slings. Rose's Fusible Alloy.— This alloy melts at 201°, and is composed of bismuth 2, lead 1, and tin 1. See Fusible Alloys. Rosin-cores. — When a core contains more or lesc rosin in its composition it is called a rosin-core. Where large numbers of dry-sand column or other cores are in constant requisition, rosin may be readily substituted for flour if a pulverizer is obtained for grinding the cheap grades bought in bulk ; besides which it is much cheaper than good foundry flour. To secure the best results, it is important that the rosin be ground very fine in order that its gumminess may be more generally disseminated throughout the mass, and thus Rosse Telescope. 359 Rosse Telescope. strengthen the green core. It may also be said that, owing to the closer intimacy of the grains of rosin, the sand-grains are spread out and a free passage is made for the gases to travel towards the vents. For small cores made from fine beach or free sand the proportion of rosin may be one to eleven; less when stronger sands are used. Should cores made from this proportion lack stiffness when green, a little molasses or glue-water will serve to increase their tenacity. Large column-cores, round or square, may be made from a mixture composed of 14 each of fire and beach sand, with 6 of moulding-sand and 3 of finely pulverized rosin added. Cores made from these ingredi- ents, if well dried and allowed to cool before removing, are extremely tough and unyielding, and for this reason the system of core-ironing may be of the simplest kind. The sands composing these mixtures being principally free sand, are at once liberated when the rosin has burned out, making the core-cleaning a matter of the least diffi- culty imaginable. See Flour; Molasses; Glue; Core- sand. Rosse Telescope. — This wonderful telescope was made by the renowned astronomer Lord Kosse (born 1800, died 1867), who devoted a great portion of his life to the improvement of reflecting telescopes, and succeeded in mounting one of 3-feet aperture at his home, Birr Castle, Ireland, in the year 1839. In 1842 the now celebrated six-foot reflector was successfully cast and polished, being finally mounted in 1845. The immense tube which contains it is 54 feet long and 7 feet di- ameter. The speculum metal employed for casting this reflector consisted of 4 equivalents of copper to 1 of tin, which is equal in weight to the following pro- portions : Copper 252.8, tin 117.8. This alloy is ex- ceedingly hard and brittle, will take a beautiful white Rotary Blower. 360 Rotary Core oven. polish, and does not readily tarnish; but, owing to its extreme brittleness, there was much difficulty experi- enced in obtaining a speculum casting of this magni- tude absolutely free from shrinkage cracks, gas-holes, and a decided tendency to warp out of shape. To obviate these difficulties, the cooling of the mass must be controlled and the gas eliminated ; all of which, we are told, was success- fully accomplished by Lord Eosse after a somewhat novel fashion. He formed the face side of his mould with hoop- irons, side by side, and edge up. When this iron bed had been thus made, the outside edge was formed with sand, and the casting poured as an open mould. The closely packed hoop-iron bed contained comparatively no gas-producing substances, as sand does, and whatever gas might exude from the metal thereon would be instantly pressed through the countless interstices by the superincumbent pressure of the metal above. See Speculum Metal ; Tlk. Rosthom's Austrian Metal for Cannon.— See GU!tf-METAL. Rotary Blower. — A machine provided with rotating pistons or vanes, the motion of which produces an increased current of air. See Blast; Blowers. Rotary Core-oven.— When properly constructed, this oven consists of a fireplace suitably located for supply- ing sufficient heat without burning the cores, and the oven structure is limited to the diameter of the rotating shelves, which are affixed to a central shaft, the lower end of which rests in a step, its vertical position being secured by a suitable contrivance at the roof. The latter, like the outer walls, must be no farther from the rotating shelves than is absolutely necessary. By this means quicker drying is obtained than would occur if unnecessary space had to Rotary Squeezer. 361 Rouge. be heated. The shelves may be either plain or grate, and as wide apart as will accommodate the class of cores to be dried. By this admirable contrivance the process of drying cores is materially facilitated, as the core-maker stands at the door, outside and away from the heat and gas, simply rotating the shelves in order to place within or carry away his cores. See Ovens. Rotary Miiddling-furnace. — See Revolving Furnace. Rotary Squeezer. — A shingling-machine used to consolidate and weld together the puddled balls and expel the cinder therefrom. There are many forms of squeezers, reciprocating as well as rotary. The rotary may be worked either vertically or horizontally. A strong cylindrical casing provided with an opening equal to about one fourth of its circumference forms the outside; the inside consists of a rotating cylinder, placed excentric to the casing, but with parallel faces. Both faces are deeply corrugated, and, as the inner cylinder revolves towards the small aperture, the puddled ball, entering at the widest part, is carried round and subjected to a gradually increased compression until it is forced out at the small end in a suitable shape and condition for passing through the rolls. The process is termed shingling. See Malleable Ieon. Rottenstone. — A brownish-gray or reddish-brown mineral, found chiefly in Derbyshire, England. Its com- position is alumina 86, silex 4, carbon 10. It is supposed to be decomposed shale. It is easily reduced to powder, and is largely used for polishing metals. See Polishing Substances. Rouge. — The light-red powder used for polishing speculums, and extensively employed by jewellers for Roughing-up. 362 Rubidium and Caesium. polishing glass and metal work. The protosulphate of iron is calcined until nothing remains but the anhydrous sesquioxide, which is afterwards submitted to fine leviga- gation. See Speculum; Levigation. Roughing-rolls. — See Malleable Iron ; Train. Roughing-up. — A term applied to the first process when covering the bricks of a loam-mould with loam. After the bricks are set three fourths of an inch back from the sweep-board, the coarse, wet loam is rubbed vigorously on the bricks to make it adhere firmly, a little more than enough being spread over. The sharp edge of the sweep-board scrapes off the surplus, leaving a rough face — hence the term. This rough face is afterwards made smooth by the application of fine loam, over which the sweep-board is again drawn in the opposite direction. See Bricking-up; Loam-board; Skinning-loam. Rubber. — See Resin; India-rubber. Rubber Patterns are patterns made from India- rubber, and vulcanized. This substance makes elegant and durable patterns for hardware castings, etc., and may be readily attached to either a card or match plate. See India-rubber. Rubidium and Caesium. — These metals were dis- covered by Bunsen and Kirchoff in 1860 in some spring- water they were analyzing. They are found in other waters, in the ashes of beet-root, in the mineral lepidolite, and are also found associated with potassium. Both these metals are closely analogous to potassium, but are more easily fusible and convertible into vapor, and also have more attraction for oxygen. Rubidium burns on Rubstone. 363 Runner-stick. water like potassium, and fires spontaneously in the air. See Potassium. Rubstone. — A prepared emery block for cleaning and rubbing scales from castings; it is an excellent substi- tute for casting-brush, and for some purposes superior; this, as well as the vitrified rubstone, is to be obtained from the supply dealers in convenient sizes for hand use. See Emery. Ruby. — A precious stone almost equal in value to the diamond. Some regard the ruby as a red variety of the sapphire. There are balas, or rose-red rubies; alamantine, or violet and brown rubies; and oriental rubies from Bur- mah and Ceylon, which are the finest red. The ruby is a silicate of magnesia and alumina, with lime, manganese, and iron in varying admixtures. See Precious Stones. Runner. — A foundry term synonymous with ' ' gate," and of general application to almost every system adopted by moulders for leading the fluid metal into moulds. For instance, the metal enters the mould by the runner; a basin is termed runner-basin ; and there is the drop- runner, the side-runner, the fountain-rxmner, the spray- runner, etc. The eliannel-basin for pouring open-sand work, and every variety of pattern for forming passage- ways in the sand or loam for the metal to course through — all in their respective localities, are recognized as run- ners. See Gate; Basin; Drop-runner, Fountain- runner, etc, Runner-box. — The wood or iron casing in which the pouring-basin is formed. See Basin. Runner-stick. — A common name, in some districts, for the gate-pin. See Gate-pin. Running-through. 364 Rust-joint. Running- steel Ingots. — See Ingots. Running-through. — A rather questionable method in some foundries of trying to produce clean sound cast- ings by forcing more or less fluid metal through the mould and out at the riser after the mould is full. If the mould manifests a condition of unrest by voiding air or steam, which should have been carried away in a more legitimate manner by the process of venting, it is well to continue the pouring slowly in order to compensate for what is thrown out at the gates and risers; beyond this it is simply waste, as neither dirt nor gas, remote from the risers, will be favorably affected by such a method, no matter how long the process is continued. The value of running through into built-up risers accrues from the increased pressure exerted on the casting. See Cut-off; Eisee. Run-up. — A foundry term, signifying that the mould is full of molten metal. If there should be any lacking, it is then called " short-run." See Short-sun. Russia Plate-iron. — A remarkably pure iron made in Eussia, which, by special processes of refining and anneal- ing, is rendered very tough and flexible. Owing to these excellent qualities, it is capable of being rolled exceedingly thin, and will bear much hammering and bending at a red heat without cracking at the edges. Rust-joint. — A quick-setting compound is made from pulverized sal-ammoniac 1 lb., flour of sulphur 2 lbs., iron borings 80 lbs.; mix to a paste with water in quanti- ties as required for use. A better cement than the above, but requiring more time to set, is made from sal-ammoniac 2 lbs., sulphur 1 lb., iron filings 206 lbs. See Cements. Rust, To preserve from. 365 Safety-lamp Rust, To preserve from. — It is commonly claimed that iron, under ordinary conditions, decomposes water, abstracts the oxygen and combines with it, and thus forms rust; but it is now asserted that the chief agent in this phenomenon is carbonic acid, which, if excluded, neither moist nor dry oxygen can affect the iron to rust it. Polished steel or iron is prevented from rusting by ap- plying a coat of paraffine, or steeping the object for a few minutes in a solution of sulphate of copper, and then transferring it into a solution of hyposulphite of soda acidulated with hydrochloric acid. The coating obtained will resist the action of either air or water. Oast iron is best preserved by rubbing with black lead. Polished work may be varnished with wax dissolved in benzine. Clean white wax may be rubbed over polished work when hot, and allowed to remain some time, after which rub over with a piece of serge. Deep-seated rust may be removed with benzine, or soak the object in kerosene for a day. Ruthenium. — This is the most refractory of all metals except osmium. It has, however, been fused in the oxyhydrogen flame. Euthenium is scarcely attacked by nitro-muriatic acid. After fusion it has a density of 11.4. See Metals. S. Safety-lamp. — This is simply ah ordinary oil-lamp enclosed in a cage of wire-gauze, which permits the light to pass out, but prevents the exit of flame. This lamp is the invention of Sir Humphry Davy. The explosions of carburetted hydrogen gas in coal-mines, from the unpro- tected lamps of the miners, caused great destruction of life, and various arrangements had been fruitlessly made to Saggers. 366 Salamander. prevent such fearful accidents. This great philosopher found that when a lamp is surrounded with a wire gauze, under J w of an inch mesh, any explosions taking place from the passage of fire-damp (light carburetted hydrogen) into the lamp are not communicated to the gaseous mixture outside. The space within the gauze often becomes filled with flame, from the burning of the mixed gases which penetrate the network, but the isolation is so complete that the explosive mixture outside is not fired. The power of wire-gauze to prevent the passage of flame may be usefully applied in the foundry. Let a wire-gauze be placed over the outlet or vent from beneath a hollow core where, when the mould has been cast, just such gases generate; the smoke and unburned gases will pass unin- terruptedly through the gauze into the atmosphere, and may be ignited with safety, as no flame can possibly reach the dangerous gases below (to cause explosion) as long as the intervening gauze is there to prevent it. See Venting. Saggers. — Oast-iron boxes in which articles of cast iron are packed, along with red-hematite ore, or smithy scales, to be converted into malleable cast iron by a process of decarbonization in the annealing-furnace. See Malle- able Cast Iron. Sagging. — If, on account of unequal distribution of the means employed for lifting flasks, etc., in the foundry, some portion of the suspended object should bend out of parallel, this term would, by moulders, be used to indicate that feature. Or, when some mould surface, as a cope-face, etc., betrays a disposition to separate from the main sand structure on account of faulty workmanship, or otherwise, it is then said to sag. Salamander. — When, through faulty charging, bad Salt. 367 Salt-cake. fuel, too heavy burdens of refractory ores, or from any fault iu the shape of the blast-furnace a scaffold should take place, it sometimes occurs that an accumulation of cinder and cold metal is formed, which proves highly refractory, and extremely difficult to remove. This obstruction is technically termed a salamander. In some extreme cases, when all other means used for their removal has been obstinately resisted, dynamite has been successfully em- ployed for that purpose. See Scaffold. Salt. — Common salt, or the chloride of sodium, is found in many parts of the world in solid beds. Sea-water con- tains about 4 ounces of salt in every gallon. The springs of New York State furnish an enormous annual supply. Eock-salt is seldom pure enough for use, and where no natural brine-springs exist, an artificial one is formed by sinking a shaft into the rock-salt and introducing water, if necessary. This, when saturated, is pumped up and evaporated more or less rapidly in large iron pans. Besides its use for preserving meats, by absorbing water from the flesh, it is used as a source of sodium in the manufacture of caustic soda, and as a source of chlorine in the produc- tion of chlorohydric acid. It fuses at a red heat, and is hence used for glazing stoneware, earthenware, etc. This property renders sea-water unfit for foundry purposes. See Sea- water. Salt-cake is the sulphate of soda as prepared for the manufacture of soap and glass. This compound is of great value as a flux for smelting valuable metals. By using a little on the surface of the metal in the crucible, the scum and dirt readily unite with the salt-cake, and the appear- ance of the metal is much improved. See Flux. Saltpetre.— See Nitee. Sand. 368 Sandblast. Sand. — Fine particles of stone or mineral. The finely granulated particles of siliceous stones constitute the beach and river sand, which, when dry, are without cohesion. The various sands are made through the agency of winds, water, decomposition by chemical action, and other agencies. See Facing-sand. Sand-bed. — The sand-bed of a cupola is the sand rammed on the bottom, on which the molten iron rests after it has been melted above and fallen down through the fuel thereon. The old or black sand off the floor, that which has been slightly burned, is the best to use for this purpose; being free from clay, it does not bake hard, and by using it a little drier than ordinary moulding-sand it may be rammed well down to a solid bed without fear of danger from blowing or boiling— a too frequent occurrence when the sand used for this purpose is close and too damp. The thickness of the sand-bed may always be in- creased when it is desired to reduce the depth from the tuyeres down, but there should never be less than 2| inches over the bottom plate. A slight down grade towards the tapping-hole is necessary to run all the iron off, but avoid too much slope, as it increases the pressure at the tapping- hole, making it more difficult to insert the bott. See Cupola; Spout; Breast-hole; Bott. Sand-Mast. — The process of engraving, cleaning, boring, and cutting glass, metals, and other substances by forcing or blowing sand, emery, powdered quartz, granules of iron, etc., upon the surface by means of steam-pressure or air-blast. Corundum 1| inches thick has been pierced by a jet issuing at 300 pounds pressure. It is also used for cleaning castings, graining of zinc-plate, cutting letters on stone and glass, frosting silverware, and many other simi- lar purposes. Sand-dusters. 369 Sandstone. Sand-clusters.— Flat, round vessels of block-tin, with fine perforations on one of the flat sides. They are used largely among hardware and stove founders for dust- ing the joints with parting-sand, instead of using the hand for that purpose. See Parting; Parting-sand. Sand-floor is that part of the foundry floor usually devoted to the production of castings in green sand, many of which are moulded in the sand-floor itself, and termed " sand-floor," to distinguish it from the dry-sand and loam- work floors. See Floor-moulding; Black Sand. Sand-mould. — A mould constructed in the sand, either in the floor or contained within flasks. In this in- stance it may be either a dry-sand or green-sand mould, the term "sand-mould" simply distinguishing it from one constructed by the processes of loam-moulding. See Loam- moulding; Green-sand Moulding ; Floor-moulding; Dry-sand Moulding. Sand Odd-part.— See Match-part. Sand-pulverizer.— Any machine that will crush lumps and grind the particles of sand together, and thus produce a thorough blending of the materials employed for producing sand and loam mixtures in the foundry. The ordinary loam-mill and crusher may be classed as such ; but for the purpose of mixing and sifting the finer grades of sand there are other excellent contrivances, with which, by means of a grinding-plate and vertical yielding bed set in below the hopper, the sand is pulverized and mixed, and finally delivered into a horizontal revolving screen to be sifted. See Eock-crusher; Loam-mill; Sand Screen. Sandstone is a rock composed of siliceous or calcare- ous grains of sand cemented together by siliceous, calcareous, Sand-washing. 370 Sand-screen. or ferruginous infiltrations, though the loose sand solidi- fies by pressure alone. The sand grains are invariably composed of quartz with a slight admixture of other min- erals, which gives rise to the variations in color. Some of these sandstones, owing to the highly refractory nature of their composition, are occasionally employed as hearths of blast-furnaces, also for the beds of air-furnaces ; but the want of homogeneity in the stone makes them liable to crack, and for this reason other refractory materials are generally preferred. See Kock-sand; Facing-sand. Sand-washing.— The process of washing sand, in order to free it from deleterious matter, and thus render it more suitable for moulding purposes, may be materially facilitated by rotating a cylindrical wire-sieve within a shallow trough, which receives a constant supply of water at one end and discharges it at the other, along with the soluble matter which has passed through the sieve. See Core-sand. Sancl-Screeii. — The ordinary sand-screen in the foundry is similar to the one used for coal and for the sand used by builders, etc. The regular sizes used for brickwork and plastering is 3- or 4-mesh, for fine sand 5-mesh, for gravel 2-mesh. These frames measure 6 feet high, 26 J inches in width. The sizes most used are J-inch openings for taking out the dust; f-inch for chestnut coal; J to |- inch for nut; f to f-inch for stove; f, 1, and 1^-inch for cleaning soft coal. These screens are made with a heavy hard-wood frame, and of extra heavy crimped wire. The frame is securely fastened together with bolts, and the wires are firmly stapled to the frame, and finished at the top and bottom with sheet iron. The revolving screen consists of a grating of wire cloth secured to a framework of iron, forming a cylindrical riddle or sieve, into which the sand Sand-sifters 371 Satin-spar. is thrown at one end. A slight iucline causes what is too large to run through the meshes to pass out at the other end as the cylinder rotates horizontally on its axis. Sand Sifters. — The common kinds of sand-sifters are made to operate by either hand or power, and usually consist of a stout oblong frame supported on four legs, in- side of which the sieve or riddle is caused to move rapidly back and forth by a mechanical device attached to the end of the frame. Some makers claim six movements of the sieve to each revolution of the driving-wheel or pulley; the object in this being to prevent clogging by imparting a constant jarring motion to the sifter. Other sifters are suspended from beams above, and an oscillating motion imparted to them by a three-toothed cam-pinion, the teeth of which thrust (alternately) ; pins in the slotted piece attached to the bar which actuates the sifter, and a rapid back-and- forth movement is imparted thereto. See Kiddle. Sapphire. — A precious stone, almost equal to the diamond in hardness. It is highly transparent and brilliant, and consists of nearly pure alumina or clay, with a minute portion of iron. White sapphire resembles the diamond. Red sapphire is called the oriental ruby; blue being the common sapphire of the ancients, and yellow the oriental topaz. See Peectous Stokes. Sardonyx. — A very beautiful and rare variety of onyx, composed of alternate layers of sard and white chal- cedony, used by the ancients for cameo engravings. See Precious Stokes. Satin-Spar. — A white fibrous limestone, which ex- hibits, when polished, a lustre like satin. It is found in England and Scotland. See Limestone. Saturation. 372 Scaffolding. Saturation. — A liquid is said to be saturated when it has taken up as large a quantity of a solid as it can dissolve, in which case the force of cohesion between the particles of the solid is equalled by the adhesion of the liquid and the solid to each other. Saturation means also the absorption of liquids by solids, the permeation of an element by other elements, etc. See Solubility. Scabbed Castings are castings on the surface of which rough and unsightly excrescences are found when the adhering sand has been removed. These imperfections arise from a variety of causes : such as imperfect venting; faults in the ramming; unsuitable material; too much coal; extreme moisture, and numerous other causes, all of which, in the great majority of instances, might be easily avoided if the intelligence of those engaged in their production was equal to the demands made on it. The moulders of to-day are deficient from both an intellectual and artistic point of view, and no substantial improvement in the quality of castings may be anticipated until a more rigorous system of apprenticeship and superior technical training shall have been adopted. This and this only will amplify the minds of our young men and enable them to intelligently trace cause and effect, and thus avoid the errors which, owing to their present ignorance, are now so frequent. See Tech- nical Education for the Moulder; Facing-sand; Venting; Kamming; Cutting; Current. Scaffold.— See Charging-platform. Scaffolding is the formation of highly refractory masses of scoria and iron upon the cupola or blast-furnace walls, which interfere to a remarkable extent with their free working. These obstructions may be caused by the Scaling-furnace. 373 Scotch Pig Iron. accumulation of refractory slag; from the use of soft fuel that is crushed by the superincumbent charges; uneven distribution of the charges; inferior fuel; too heavy bur- dens ; etc. Most of the conditions enumerated act by obstructing the blast, and thus interfering with a free ascent of the gases ; the furnace loses heat, and the slag coagulates and favors the formation of scaffolds. In the ordinary cupola a scaffold may be removed by the intro- duction of finely divided fuel at the tuyeres, which are di- rectly underneath the offending mass, reducing the blast somewhat until the obstruction begins to yield; and it is sometimes possible to loosen them off by means of a long bar from the charging-hole ; but in the case of blast-fur- naces more drastic measures must be employed. See Charging ; Katio of Fuel to Iron ; Salamander. Scaling-furnace, as its name implies, is the fur- nace in which plates have the scales removed by the appli- cation of heat. Scoria. — The cinder and slag rejected after the reduc- tion of metallic ores, or the superfluous matter of metals in fusion. See Slag. Scotch Pig Iron is a brand of iron that in the past has been highly esteemed by founders almost everywhere for its softness and fluidity, as well as for the particular quality of retaining its heat when melted for a much longer time than most other irons. This remarkable iron is made from ores and coal eminently adapted to the pro- duction of No. 1 irons. The particular quality of fluidity which it possesses is owing to the presence of a large pro- portion of phosphorus; but many of these brands are high in both manganese and combined carbon, which renders their use for strong castings that have to be tooled very Scrap metal. Screw-jack. undesirable. When these irons have been low in the latter- mentioned elements and correspondingly high in silicon and graphitic carbon, they have been unquestionably suc- cessful as softeners; but the following comparison of a cheap No. 2 American with a high-grade Scotch iron will show that our domestic brands are far superior as softeners — a fact that is becoming more widely known by foundry- men, as the decreased imports testify. This shows the Silicon. Phos- phorus. Manga- nese. Sulphur. Graphite. Com. Carbon. American No. 2. 3.81 .49 .15 .04 3.26 .04 Scotch No. 1. 1.70 1.10 1.83 .01 3.50 .40 softening element, silicon, to be much higher in the Ameri- can brand — while phosphorus, manganese, and combined carbon, all hardening, are almost absent by comparison with the Scotch. See Softeners; Silicon. Scrap-metal. — Fragments of cast-metal to be re- melted, or of malleable iron. The latter, when reworked in the forge by piling, heating, and rolling, is sometimes converted into the strongest iron by reason of the twisted fibre imparted to the forgings. Oast-iron scrap of good quality forms a good corrective in all mixtures when the resultant casting made from the pig iron in stock would be too soft and graphitic. See Mixing Oast Iron; Bugs; Silicon; Softeners. Screen. — See Sand-screen. Screw-jack, or jack-screw, is a lifting-machine in which the power consists of a strong screw, which is made to rotate by means of a large nut which rests upon a base or pedestal. It is raised or lowered by turning the nut. Screw-moulding. 375 Screw Propellers. Screw-moulding. — Cast-iron screws for conveyors and elevators are made in greensand by screwing a section of screw through the entire flask; first bedding the shaft with section attached in the lower flask, making joint half- way and ramming thereon the cope, which, when the pat- tern has been screwed out endwise, may if necessary be separated for finishing. Screw-plates.— See Kapping-plate. Screw Propellers.— A screw propeller is a similar construction to the common screw, except that the thread enlarges to a plate as the cylinder diminishes to a spindle. It acts much as a bolt in a fixed nut. When placed under the ship and revolved, the screw advances, pushing the ship, and the water is thrust backwards. John Stevens, of Hoboken, employed a screw propeller in 1804. In 1836 patents were granted to Capt. J. Ericsson, United States of America, and Francis P. Smith, England, which resulted in their final adoption as a regular mode of propulsion for steamships. Propellers are cast from bronze, steel, and cast iron — some whole and others with boss and blades as sep- arate castings. The latter may very readily be all made in greensand. Large numbers of small wheels are made from entire patterns in greensand. An improved method of moulding small wheels in greensand from one blade and an equal section of hub secured to a nowel-frame of wood, cut to the shape of the joint, allows of the pattern being rammed therein, the joint made, and an impression of the upper side being taken in a close-fitting cope, also of wood. This whole process, being performed upon a lifting-plate that stands within the nowel-frame, permits the blade- moulds when placed together to be arranged in their respec- tive positions upon a level bed, and all rammed with a containing flask or curb. The covering-plate, weights, and Scruple. 376 Sculpture runners complete the operation. Larger wheels are made in dry-sand from one-blade pattern with hub attached, the latter being made to fit a central spindle that rests on a foundation-plate on which as many nowels are fixed as there are blades to the wheel. The copes, being separate ones, are rammed in succession over the pattern, as the lower surface of the blades are alternately formed in each nowel. When all the blades have been moulded by this means, the whole mould is finished, blackened, and dried for casting. When small and medium-sized wheels are made in loam, the whole of the blades are formed upon one foundation-plate ; very large ones have a separate foundation-plate for each blade. An outer swept-bearing, just beyond the brickwork of the blades, serves as a rest for the inclined plane on which the sweep-board, attached to the free arms of the spindle, must be made to travel, and which gives the pitch of the wheel. Bottom and top sur- faces of the blade are struck with this board, which is set at right angles with the spindle, a tapered thickness or guide-piece being attached when the blades are made face up. If the blades are to be cast face up, the moulds are carved out of the loam; if face down, then some pattern device is schemed, in order to give the cope impression. The piers or nowels are built of bricks and loam; but the copes are carried off in iron frames, so constructed that a good loam impression of the blade along with that portion of the hub may be lifted away, to be again returned when the whole mould has been dried, and all is ready for bind- ing and ramming together in the pit. Scruple. — The scruple is the 288th of a troy pound ; the 24th of an ounce ; the third part of a drachm, and contains 20 troy grains. Sculpture is an art in which, by means of taking away Sealing-wax Impressions. 377 Sea-water. or adding to matter, all sorts of figures are formed either in clay, wood, wax, stone, or metal. The art of sculpture, in its most extensive sense, comprehends not only carving in wood, stone, or marble, but all enchasing, engraving in all its kinds and casting in bronze, lead, wax, plaster, as well as modelling in clay, wax, or stucco. See Statuary- foukding; Plaster Cast; Modelling; Stucco. Sealing-wax Impressions. — Sealing-wax is a very handy and useful substance for obtaining any particu- lar impression to be afterwards inclosed within or attached to a pattern for moulding in sand. The wax must be of good quality and melted in a metal vessel over a lamp, after which the pattern can be pressed down upon the wax just before it congeals, and a beautiful impression will result if the pattern is thoroughly clean. Sealing-wax im- pressions make good moulds for plaster. Sea-coal Facing.— See Coal-dust. Sea-water is water impregnated with salt in solution. It is generally composed of chloride of sodium 2.50, chloride of magnesium 0.35, sulphate of magnesia 0.58, carbonate of lime and carbonate of magnesia 0.02, sulphate of lime 0.01, water 96.54. It will be seen from the above why sea-water is utterly unfit for foundry purposes, as, in the subsequent process of evaporation, the chloride of sodium or common salt is de- posited in innumerable crystals among the sand; and this deposit being volatile at furnace heat must flow as a slag immediately it is brought in contact with the molten metal. This explains why, where sea-water is employed, castings invariably show dull gray deposits on the surface, which utterly destroy all beauty of finish, and render them unfit for any but the commonest purposes. The slag pro- Seating. 378 Separating-machine. duced is also a source of annoyance when the castings must be tooled. See Salt; Daubing. Seating". — A guide-bearing or rest for cores or mould sections. In vertical loam-work the cope or the core, and sometimes both, are made as separate portions of the mould, and must be lowered into their respective positions when the mould is closed together in the pit. In order that this may be done accurately, a tapered seating is formed at the bottom of the mould, extending some few inches below the casting. By this device the smallest end of the core is made to enter at the widest diameter of the seating, and is thus guided to the bottom-bearing, when the sides meet close together at a true centre. The cope is the opposite to this, its widest diameter seeking a true location by in- closing the small end of the seating first, and gradually em- bracing it closer and closer until the bottom-bearing is reached, when the diameters correspond and the section is central. The tapered sides of an ordinary core-print rep- resent the seating for a core. See Cope-ring; Print; Guide. Seniilor. — A cheap imitation of gold, used for common articles of jewelry. The composition varies from 2 to 5 copper, and 1 zinc. See Gold; Tombac Semi-steel. — See Puddled Steel. Separating-machine (Woodruff's) is an in- genious combination of vibrating screen and fan for extract- ing shot and other small iron from foundry refuse. It occupies ground space about four by eight feet; requires about one and a half to two horse-power to drive it; can be set up anywhere, in doors or out, under shed, where power can be had. Separating Metals. 379 Separating Metals. A barrowf ul of refuse will pass through the separator in three or four minutes, all the iron being deposited in box provided for it, and all other materials thrown to rear of machine. Separating Metals from their Alloys.— Tin may be separated from copper by digesting in nitric acid, which dissolves the copper— the tin remaining in an in- soluble peroxide. Copper is separated from lead by adding sulphuric acid to the nitric solution and evaporating to dryness, when water digested on the residuum will dissolve out the sulphate of copper, leaving the sulphate of lead behind. From this solution the oxide of copper may be precipitated by pure potassa. The precipitation of copper in the metallic state is obtained by immersing polished steel into the solution. Copper is separated from zinc by sulpuretted hydrogen, which will throw down a sulphuret of copper, which may be dissolved in nitric acid and precipitated as before. Silver is separated from copper by first reducing the alloy to powder, and then digesting in a solution of chloride of zinc, which dissolves the copper, leaving the silver un- changed. Or, mix sulphuric acid 1 part, nitric acid 1 part, water 1 part; boil the metal in the mixture till it is dis- solved, and add a little salt, which will cause the silver to subside. Copper is separated from its numerous alloys — as lead, tin, antimony, iron, bismuth, etc.— by melting the alloy, and fusing for about an hour with one part each of black oxide (copper scales) and bottle-glass to every ten parts of the alloy. The copper will fall to the bottom of the crucible; the other metals and impurities either volatilize or dissolve in the flux. If lead and tin are in solution, the lead may be precipi- tated by sulphuric acid, and the tin with sulphuretted Setting. 380 Shackle. hydrogen gas. In an alloy the lead will dissolve in nitric acid, leaving the tin as an oxide. Zinc and iron may be removed from plumber's solder by digesting the grain metal in diluted sulphuric acid. The acid first dissolves the zinc, then the iron, and all traces of these metals are removed by subsequent washing. Tin may be separated from Britannia and similar alloys by melting the metal and sprinkling sulphur over it; after which stir the metal in the crucible for a while, and the other metals will burn out, leaving the tin pure. Gold is separated from silver by melting the alloy and pouring from a height into a rotating vessel containing cold water. This granulates the alloy, which is then treated with nitric acid and heated. The product is nitrate of silver, which is reduced in the ordinary manner, and metallic gold as a black mud, which is washed and remelted. Setting. — This term is applied to metal as it passes from the fluid to the solid state. When the metal has concreted into a solid mass, it is termed "set" or "frozen," both of which terms are in the foundry synonyms for congelation. See Congelation; Feeezing. Shackle.— A link with an open end, the extremities of which are forged to receive a pin or bolt, by which means a connection may be made with a chain; or it may be em- ployed to join two chains together. Some are made link- form, and others are made like a ring. Their chief use in the foundry is to handle heavy cores and flasks, for which reason the eyes should be always made large in order that strong pins or bolts may be inserted. If pins are used, one end should be jumped and the other keyed, to prevent slipping out. The nut answers this purpose when a bolt is used. Shakdo. !1 Shears. Shakdo is a Japanese bronze of great beauty, the composition of which consists of copper containing from one to ten per cent of gold. Its bluish-black color is pre- served by boiling the polished article in an artificial bronze solution composed of sulphate of copper, alum, and verdi- gris. See Bronze. Shale is a hard, slaty clay composed chiefly of silica and alumina, but in some instances containing lime and oxide of iron. It forms in the coal-measures and often contains a quantity of bitumen: it is then known as bituminous shale, from which variety shale-oil is obtained by distillation. Shale has a slaty structure, generally grayish black in color, but red when iron is present. Slate- pencils are made from it, and when free from iron and lime it is ground up and used for making fire-bricks. See Bitumen. Shank.— A foundry-ladle for holding molten metal. It is distinguished from the hand and crane ladles by its mountings, which consist of an encircling wrought iron belt, to which is welded the single and double ends for carrying it away by hand. Shanks are made of both cast and wrought iron (the latter to be always preferred), and their capacity ranges from 100 to 400 pounds. Small shanks arc, managed by two men, the larger ones requiring from three to five men, according to the weight of metal carried away. They are sometimes made to hold a ton or more, but are then lifted in a bale by means of the crane, and these are neither as safe nor as handy as when suitable gearing is attached. See Ladle ; Hand-ladle ; Crane-ladle. Shears.— A machine used in forges and rolling-mills for cutting up puddle-bars into suitable lengths for piling, Shear-steel. 382 Sheathing-metal. trimming the edges of sheets, plates, etc. Crocodile or alligator shears are generally some form of lever-shears consisting of a fixed bottom jaw or knife, to which at the root of the knife is attached the vibrating-arm or lever- jaw. A crank or excentric at the opposite end of the lever causes the upper jaw to open and shut after the manner of an alligator's mouth; hence the name. The plate - shearing machine is made with diagonal -edged knives of considerable length; the bottom one is fixed, and the upper has a vertical motion within parallel guides. These are employed for sheet and plate work. Guillotine- shears are similar in design to plate-shears; but, as their use is for cutting up the hot steel ingots into lengths suit- able for subsequent operations in the mill, the knives are much shorter and the guides closer together, giving the machine an appearance of the instrument from which it derives its name. There are also numerous designs of combined shear and punch, both of which motions are derived from gear connection with the fly-wheel. Hydraulic shears may be of two forms : the stroke is either upward or downward, according to the position of the press. Shear-steel. — Shear-steel of commerce is classified as double and single shear steel. Owing to the imperfec- tions of blister-steel, it is not suitable for the manufacture of cutting instrument, as shears, knives, etc., until it has undergone the processes of cutting, piling, reheating, and welding together again under the hammer or by rolling. The resultant bar is shear-steel; this, when cut up or doubled upon itself, reheated, and again hammered or rolled, is double-shear steel. See Blistek-steel. Slieathing-metal is a metal or alloy which, when rolled into sheets, is employed for covering the bottoms of wooden ships to protect them from worms, etc. Muntz's Sheet Iron. 383 Sheet Lead. metal for this purpose is copper GO, zinc 40; but he states that any proportions between the extremes of copper 50, zinc 50, and copper 63, zinc 37, will roll and work at a red heat ; but copper 60, zinc 40 is always to be preferred. The cast ingots of this alloy are heated to about 200° and rolled into sheets, the same heat serving for work- ing this alloy into other shapes, as bolts, etc. Numer- ous other alloys are employed for this purpose, amongst which may be noticed: Mushet's — copper 100, zinc •§•; Ool- lins's red sheathing-metal — copper 8, zinc 1; Collins's white metal— copper 1, zinc 16, tin 16; Pope's — lead 1, zinc 3, tin 2; all of which may be heated and worked as previously described. The nails used for fastening the sheathing are composed of an alloy of copper and tin. See Brass. Sheet Iron is rolled from the bloom direct, or from slabs and piles. It is brought to a welding heat and passed through the slabbing or roughing rolls, end and sidewise, according as it appears to require distention, until the mass has been reduced sufficiently for final rolling in the finishing-rolls where, being now brought by the previous operations to the required width, it is passed through entirely in the direction of its length. Gauges of the length, breadth, and width indicate when to discontinue rolling. The exact size is obtained by means of plate- shears. See Malleable Iro:n". Sheet Leatl. — One method of making sheet lead is to surfer the melted metal to run out of a box or vessel through a long horizontal slit, upon a table covered with sand, when the box is drawn over it, leaving the melted lead behind to congeal. These sheets may then be rolled to any desired thickness, and also made more uniform. A later improved method is to cast thick square blocks of lead, which are subsequently drawn into long sheets be- Shell-gold. -384 Shingling. tween two heavy rolls; the sheet in the meanwhile being supported upon a long table which travels on wooden rollers. Another method is to force the metal by hydraulic power through the annular space formed by an outer cylin- der and central core. This makes lead-pipe, which may be slit lengthwise and opened out into sheets. The Chinese pour melted lead upon a paper-protected flagstone, and press it down into a sheet by applying another similarly prepared stone above. See Lead. Shell-gold. — The thin beaten gold used by decorators. See Gold. Shell-lac. — A resinous exudation from the branches of several trees in the tropics. The crude lac is called stick- lac ; this is bruised, the fragments of wood removed, and the resin digested in weak carbonate-of-soda solution. The residue is the seed-lac of commerce, which when melted down becomes shell-lac. See Kesik. Shell-moulding.— See Hollow Shot. Shells. — The shells of oysters, clams, etc., and of the eggs of birds, are composed almost wholly of carbonate of lime, cemented by a very small portion of animal gluten; while those of lobsters, crabs, etc, generally consist of only half carbonate of lime, the remainder being animal matter with a small proportion of phosphate. See Carbonates; Lime Shingling. — The process of detaching impurities, as cinder, etc., from the blooms of puddled iron by ham- mering or compressing the ball, and thus preparing it for immediate conversion into bar iron by rolling. See Mal- leable Iron; Botary Squeezer. Short-run. 385 Shrinkage. Short-run. — A foundry appellation for a mould or casting which has been spoiled by being only partially filled with molten metal. See Kun-up. Shot. — See Hollow Shot ; Lead-shot ; Projectiles. Shot-nietal. — See Lead-shot. Shot-tower. — See Lead-shot. Shovel. — An instrument consisting of a flat or scooped blade and a handle; it is used for digging and throwing sand, earth, etc. Moulders' shovels are of two kinds — heavy and light, the former for digging, the latter being specially made to meet the requirements of stove-plate, bench, and other light- work moulding; but both classes of shovels should be made of the best cast steel, and well polished. The handsomer and better the tool, the greater will be the care exercised to preserve it, so that in the end the best is the cheapest. Besides this fine grade for moulders, there are plain black polished ones of a stronger make, adapted for rough use on the gangway and scrap- piles, which answer these purposes just as well as the best, and are much cheaper. Special shovels and scoops are made for coal; but for coke handling, especially round the cupola, the fork is to be always preferred. The square- bladed digging-tool is usually termed a spade. See Coke- fork. Shrinkage. — A contraction or shrinking of materials into a less compass as they change from a hot to a cold state. Some hard irons shrink or contract f of an inch in 12 inches, while soft irons of choice grades will sometimes not exceed ^g-. Medium grades of good quality generally shrink about y 1 ^ of an inch in 12 inches when used in heavy Shrinkage. 386 Shrinkage. castings; but in light castings the same brand will as a rule show J of an inch in 12 inches. Bronze shrinks about T 3 g- of an inch in 12 inches. General brass work, accord- ing to mixture, will shrink from -^ to J- of an inch in 12 inches. Copper shrinks T 3 g, tin about J, silver £, lead -£%, zinc and bismuth each T 5 g- of an inch in 12 inches. These can only be approximate measures of shrinkage; the exact amount which takes place in any particular casting must necessarily be determined by its general outline and bulk, and to some extent by the temperature of the metal used for casting with, dull metal always favoring the least con- traction. Very little if any shrinkage would seem to occur in heavy castings of limited compass, but what in this in- stance seems to be lack of shrinkage is in all probability to be attributed to distention of the mould under extreme pressure. The metal remaining fluid a longer time in this class of moulds than is ordinarily the case, gives ample opportunity for the pressure to act upon the mould surfaces to severely try them. Bottoms of cylinders and pipes would appear to shrink more than the tops ; but it is a mistake to say they do. The smaller diameter at that point is because the material of which the core is composed can- not effectively resist the extra pressure to which the lower portions of all deep moulds are subjected. When 12 feet added to the depth will make a difference in pressure equal to about 37 pounds per square inch, it is plain that unless extraordinary measures are adopted to resist this added pressure, cylinders will always appear to shrink more at the bottom than top. The commonly accepted theory that castings shrink less vertically than in any other direction is undoubtedly wrong also, and similar reasons may be advanced to refute this as in the case above, especially when the upper flask or covering-plate is connected with a system of coring, the bottom surfaces of which extend a consider- able distance down. These extra strains, if not resisted Shutter. 387 Silica. absolutely both at the top and bottom, gives an increased length to the casting, which in many instances exceeds the legitimate shrinkage. Gear-wheel rims shrink less when the arms and hubs are cast on than when made as a separate casting, and it may always be expected that the heaviest wheels will shrink the least. The same may be said in reference to other classes of castings, which are composed of cross-ribs and plates internally; these will in- variably shrink less than open castings, such as plain frames, etc. Shrink-head.— See Riser ; Feeding-head. Shutter. — The cast or wrought iron plate which, when suitably prepared with a loam daubing on both its sides, is set before the flow-hole inside the dam for the purpose of regulating the stream issuing from thence. A lever is usually employed to control it. Smaller shutters are em- ployed to check or turn the stream of metal issuing from the furnace to a mould direct. When the metal is allowed to collect in a large sand -basin before entering the mould, the shutter controls the stream. See Dams. Siemens - Martin - Steel. — See Open - hearth Steel; Regenerative Furnace. Sieve. — A fine riddle, usually made from brass wire, and used for mixing and separating the finer grades of sand, etc., in the foundry. See Riddles. Silex. — A generic name given to flint-stone, pure quartz, silica, and all minerals in which a large proportion of silica is present. See Silica. Silica.— One of the most abundant substances found in nature. Silica is the chief component of a number of Silica Bricks. 388 Silicon. precious stones, of rock-crystals, agates, porphyry, granite, flints, sandstone, and sand. When perfectly pure it is a fine powder, very hard, and will wear away glass. When mixed with water it does not adhere, but falls to the bottom, leaving the water clear. It fuses in the oxyhydrogen blowpipe, and may be drawn into threads after the manner of glass. When silica is mixed with alkalies it melts at a lower temperature, and combines with them to form glass. The minerals, feldspar, mica, hornblende, serpentine, etc., which form the granitic and many other rocks are silicates of the alkalies and alkaline earths. Glass and pottery are compounds of silica with various metallic oxides. See Granite. Silica Bricks are made by incorporating about 50 pounds of lime-paste with a ton of crushed Dinas rock from the Swansea Valley. This rock contains about 97 per cent of silica, and the bricks produced from it are employed chiefly for the roofs and all exposed parts of the open-hearth steel-melting furnaces, and other similar pur- poses where the operations demand the most intense heat. See Open-hearth Oast Steel. Silicon. — This substance is the base of silex or silica, and is now supposed to be a non-metallic element. More or less of this element is present in all varieties of pig iron, but whether in chemical combination or otherwise it has not yet been satisfactorily determined. Silicon acts to change the combined carbon in cast-iron to graphitic car- bon. Describing the result of his experiments for ascer- taining the influence of silicon upon cast-iron, W. J. Keep says : " We have seen, however, that a white iron which will invariably give porous and brittle castings can be made solid and strong by the addition of silicon; that a further addition of silicon will turn the iron gray, and that as the Silicon Bronze. 389 Silicon Steel. grayness increases the iron will grow weaker ; that excessive silicon will again lighten the grain and cause a hard and brittle as well as a very weak iron ; that the only softening and shrinkage-lessening influence of silicon is exerted dur- ing the time when graphite is being produced, and that silicon of itself is not a softener, or a lessener of shrinkage, but through its influence on carbon, and only during a certain stage, it does produce these effects." To produce highly siliceous iron, or siliconeisen, in the blast-furnace the blast requires to be extremely hot, the furnace driven slowly, and the charges, while containing much silica, must be highly aluminous and not markedly calcareous. When 20 per cent of silicon is present in siliconeisen the amount of carbon in the alloy is very low. To prevent honeycombing in soft cast steel which con- tains very little carbon, an alloy containing 8 per cent sili- con, about 15 per cent manganese, and 1.3 per cent carbon is employed extensively in some steel manufactories. The presence of silicon along with manganese acts to diminish the formation of honeycomb in steel ingots. See Honey- combing; Softeners; Analysis. Silicon Bronze.— See Telegraph and Telephone Wire. Siliconeisen.— See Silicon. Silicon Steel.— This steel is made by adding some siliconeisen or specially prepared siliceous pig along with the ordinary spiegeleisen or ferro-manganese which it is customary to mix with the molten metal, reducing the latter sufficient to admit the siliconeisen. The result is a steel containing from 0.2 to 0.3 per cent silicon, which is largely employed for steel castings. Silver. 390 Silver Alloys. Silver. — This metal is found native and in combina- tion with sulphur, as the sulphides of lead, antimony, and copper; native silver occurs in fibrous or crystalline masses. The metal is obtained from the sulphuret by mixing the crushed ore with salt and roasting it, by which means it is converted into a chloride which, together with water, iron scraps, and mercury, is revolved in a large barrel. By this process the chlorine is removed by the iron and the mer- cury amalgamates with the silver, from which it is subse- quently freed by distillation. Silver is freed from lead by melting the alloy and cooling slowly; the lead then solidi- fies in crystals, leaving the almost pure silver. The process of cupellation in shallow porous vessels made from bone- ashes gives a still greater degree of refining. Being melted with access of air, the lead oxidizes ; the oxide or litharge melts, and, being absorbed by the cupel, the silver is left pure. Silver is the whitest of all metals, of high metallic lustre, is very ductile and tenacious, may be hammered to the ten-thousandth of an inch thick, and one grain may be drawn into four hundred feet of wire. Polished, it is an excellent reflector of light, and it is a good conductor of heat and electricity. To give silver the requisite hardness for coin and silver-plate, it is usually alloyed with about one tenth of its weight of copper. The specific gravity of silver is 10.5, and it is harder than gold, but softer than copper. See Amalgamation ; Mebcuky Metals. Silver Alloys. — For silver-plate and medals — silver D5, copper 5. Silver solder for jewellers — silver 19 dwts., copper 1 dwt., brass 10 dwts. A hard silver solder is com- posed of silver 6, brass 2; the one most common, and which is softer than the last, has silver 4, brass 2. See Imitation" Silver; Mock Silver; German-silver; Brass. Silver Imitations.— See Imitation Silver. Silvering. 391 Silvering. Silvering. — A silver-plating solution is made and applied as follows : Put together in a glass vessel 1 oz. nitrate of silver, 2 oz. cyanuret potassa, 4 oz. pre- pared Spanish whiting, and 10 oz. pure rain-water. Cleanse the article to be plated by washing over with dilute nitric acid or potash-lye and prepared chalk, and apply with a soft brush. Finish with the chamois-skin or burnisher. Silvering with the Plating Powder. — Dissolve silver in nitric acid by the aid of heat; place some pieces of polished copper in the solution to precipitate the silver; wash the acid out in the usual way; then, with 15 grains of it mix 2 drachms of tartar, 2 drachms of table-salt, and i drachm of pulverized alum. Brighten the article to be plated with ley and prepared c^alk, and rub on the mixture. When it has assumed a white appearance expose to heat, and then polish with the chamois or burnisher. G-ood for clock-dials and barometer scales. Silvering Metals, cold. — Mix 1 part of chloride of silver with 3 parts of pearl-ash, 1J parts common salt, and 1 part whiting. The article to be well cleaned, as before directed, and the mixture rubbed well on with a piece of cork moistened with water. When silvered wash the article in hot water, slightly alkalized; then wipe dry. Silvering by Heat. — Dissolve 1 oz. silver in nitric acid; add a small quantity of salt; then wash it and add salammoniac, or 6 ozs. of salt and white vitriol; also \ oz. of corrosive sublimate; rub them together till they form a paste; rub the piece which is to be silvered with the paste; heat it till the silver runs, after which, dip it in weak vitriol pickle to clean it. Silvering Solution for Electro-plates. — Nitrate of silver 2 drachms, distilled water 37 drachms. Dissolve, and add salammoniac 1 drachm, hydrophosphite of soda 4 drachms, precipitated chalk 4 drachms. Agitate the preparation Silver Powder. 392 Sinking-head. occasionally for 12 hours, when it will be ready for use. Apply with a fine sponge. Silvering Mirrors. — Silver, instead of mercury, is now much used for this purpose. The deposition is effected by pouring over the glass a mixture of alcohol, nitrate of silver, carbonate of ammonia, and ammonia, to which has been added a few drops of oil of cloves. A gentle heat is applied for two or three hours, when the surface becomes coated. The residue is poured off, the film of silver dried and var- nisl;eJ. Silvering Shells. — Silver-leaf and gum-water, a sufficient quantity; grind to a proper consistency, and cover the inside of the shells. For gold use the gold-leaf in the same man- ner. Silvering Glass Globes. — Lead 1 part, tin 1 part, bismuth 1 part ; melt, and just before it sets add mercury 10 parts. Pour this into the globe and revolve rapidly. See Plating; Mercury. Silver Lead. — See Graphite; Black Lead; Facing-. Silver-pl ating. —Plating ; Silvering. Silver Powder. — Melt one part each of tin and bis- muth; then add one part mercury, just before it sets. When cold this is powdered and used by japanners. Silver Solder.— See Silver Alloys; Solders. Silver Steel. — Extra fine steel for the keenest cut- ting instruments. Some makers alloys this with an exceed- ingly small proportion of silver. Similor. — Gold-colored brass. See Semilor. Sinking-head. — So called because the molten metal Sister Chains. 393 Skeleton. falls or sinks out of it into the shrinking casting below. See Feeding-head; Riser. Sister ChaiiiS.-Two distinct pairs of foundry lifting- chains, having similar parts throughout, each one of which is an exact counterpart of the other — as, "sister buckle chains," sister sling chains," etc. Size. — A kind of soft glue made from skins, hoofs, membranous tissues, and other parts of animals, by boiling for some hours, then dissolving, straining, and again boiling to a jelly-like consistence. Gilder's Gold Size. — Boiled linseed-oil thickened with yellow or calcined red ochre, ground smooth and thinned with oil of turpentine. Letters on Glass. — A size for this purpose is copal varnish one part, Canada balsam two parts. Another : pure mastic varnish, or pale, quick-drying copal varnish. Artist's Size. — Dissolve over the fire in a pint of water 4 ounces of Flanders glue, 4 ounces of white soap; then add 2 ounces powdered alum. Stir the whole and leave to cool. Size to fasten Rubber to Wood or Metal. — Soak pulverized gum-shellac in ten times its weight of ammonia; in three or four days a shiny mass is obtained, which will become liquid without the use of hot water. This softens the rub- ber, and becomes, after the volatilization of the ammonia, hard and impermeable to gases and fluids whenever it is used on rubber connected to the wood or the metal of steam or other apparatus. Skeleton, — A frame made by the pattern-maker from which, by the aid of outside and inside strickles, the loam-moulder constructs his mould without employing a Skeleton Core-iron. 394 Skim-gate. full pattern. A convenient and cheap device for the pro- duction of tanks, condensers, etc., that are rectangular in form. Also, for moulding cylindrical objects, as steam- cylinders, etc., in loam. A skeleton-frame for this purpose consists of bottom and top flanges, in the rough, connected by a few lags vertically, which serve to fasten thereon steam-chest, feet, exhaust-belt, brackets, etc., at once, and thus obviate all possibility of the errors which frequently occur when these attachments are built separately into the brickwork. The skeleton-flange rests on the swept seating or guide-bearing. After the cope has been built to a tem- plate the screws are taken out from the inside, skeleton- frame taken away, and the loam swept on the surface by means of the spindle and sweep-board. See Loam-mould- ihg; Seating. Skeleton Core-iron.— A core-iron consisting of wrought or cast iron rods cast in one or more plates or rings. It is the most efficient and convenient core-iron that can be made for any description of belt or jacket- core having metal on all its sides. Owing to their cage- like appearance, they are frequently termed cage-irons. See Jacket-cores. Skim-gate is any arrangement of runner that will arrest the skim or slag at some part intermediate to the pouring-basin and casting. If two castings are poured to- gether in one flask, and one of the moulds filled by means of a fountain or horn runner connected with the bottom of that which receives the metal direct from the ladle, it is evident that all the dirt will remain in the latter, while the clean iron only will be forced into the former, thus making one casting a skim-gate to the other. Any inter- mediate receptacle, not necessarily a casting, may be thus employed to intercept the dirt; but by inserting a spherical Skimmer. 395 Skin. object, as a ball, etc., for this purpose, and allowing the metal to enter it at a tangent to the circumference with force sufficient to impart a rapid rotary motion to the entering metal, the lighter scum is forced to the centre and there held until the casting or castings gated from the circumference of the ball are filled with clean metal. In order that this may be effective, the metal must enter the ball with force sufficient to keep it full, so that the castings may be fed from a point below where the dirt is lield imprisoned. If a large quantity of metal must neces- sarily pass through a ball of limited size, a riser on the ball permits the accumulations to mount well above the ingates. See Gates; Fouktaik-kunner. Skimmer. — A tool for preventing the dirt and slag from following the stream as the metal flows from the ladle-lip into the runner. They are simply of wood in some foundries; but generally they consist of a long piece of flat iron bent at one end, or a long light bar to which is welded a stronger piece of flat iron bent to fit the ladle-lip. The self-skimming ladle is intended to obviate the neces- sity for skimming. See Ladle; Lip. Skin.— The surface, either of a mould or casting, is designated as the skin by most foundrymen. The aim of a conscientious moulder is to produce castings exactly like the model or pattern, externally and internally; free from blown and shrunk holes, no cold-shuts, and to present a clean surface or skin — the last being to him the chief desideratum. To obtain the latter quality in the resultant casting many schemes are practised in order that the in- tensely hot and liquid metal may be prevented from pene- trating beyond the skin of the mould; the chief agent employed for this end being carbon, which is contained in Skinning- ioam. 396 Slag some proportion in nearly all the facings made. See Facing; Facing-sand; Graphite. Skiimiiig-loam. — Fine loam or slip which, by means of the spindle or guide and the requisite strickles, gives the final shape to and constitutes the surface of swept moulds. See Loam; Roughing-up. Slack. — Fine coal or screenings. See Pressed Fuel. Slacked-lime.— See Lime-kiln. Slag". — Cupola slag is sometimes called " scoria" or "cinder," and consists of the fused compounds of the silica and alumina in the lining, daubing, and dirt which are too frequently thrown in among the iron and fuel. Impure fuel also adds its quota to this readily fusible mass, in addition to that given off by the metal itself. If, on account of burnt or dirty iron being used, it be deemed necessary to employ limestone or anything else as a flux, the quantity of slag is augmented considerably, and means must be provided for conveying some portion of it away, otherwise it will prove a serious detriment to the effective action of the cupola, as at every rise of the, metal in the bottom this superfluous slag is forced upwards among the fuel in the immediate vicinity of the tuyeres, where by the action of the blast it is converted into an im- penetrable mass, through which ultimately no air at all can be forced. Another evil attendant upon this over-abun- dance of slag is that it must inevitably make its appearance at the tap-hole on the instant of the issuing stream failing to completely fill the orifice, defiling ladles, and everything else it comes in contact with; making it necessary some- times to clear all away, and permit its being blown out at the tap-L ne into the pit below. Slag. 397 Slag. An effective remedy for this is to copy the tymp and dam stone of the smel ting-furnace, and, like the smelters, allow this slag to now away, while the molten iron is allowed to collect comparatively clean on the sand-bed below. By making a large tap-hole some distance below the tuyeres, at a convenient part back of the cupola, a spout may be attached for leading the liquid slag away. This hole is to be prepared somewhat after the manner employed for the tap-hole, and kept securely plugged when not re- quired. When it is thought advisable to flow off superfluous slag, allow the molten iron to rise in the bottom until the slag makes its appearance at the hole, when the clay plug may be taken out, and it will at once issue forth. If this operation be conducted in a proper manner, and repeated from time to time, there need be no trouble from this source at the spout; and if due attention is paid to the tuyeres (see Tuyeres), the duration of a heat in the cupola may be prolonged indefinitely. When clean pig iron, of good ordinary quality, along with pure cast scraps, free from sand and rust, is melted with coal or coke comparatively free from impurities; and when the operation is conducted according to the best rules for practice, in a well-kept cupola supplied with blast at an adequate pressure for perfect combustion, and no more ; and allowing that the melting is not protracted beyond a reasonable time — there is really no need for a flux; and as, under the conditions stated, little or no slag would be likely to gather, it is plain that the need of slagging cupolas will only occur in proportion as such conditions fail of being met. See Cupola ; Charge ; Ratio of Fuel to Iron; Scrap; Bugs. Slag on the Surface of Castings.— See Facing- sand : Sea-water. Slate. 398 Slicker. Slag-wool.— See Mineral Cotton. Slate. — A highly metamorphosed clay rock, consisting ing essentially of clay. The particles are so mechanically arranged that it splits into plates that are independent of the layers of deposit, and are of a blue, green, gray, or black color. Its hardness prevents it from injury when exposed to the weather; it is therefore well adapted for roofs of houses, etc., and is in great demand for enamelling mantels and other objects, being by this means made to imitate the most expensive marbles at slight cost. Extensive quarries of this substance are worked in Cornwall, Wales, Ireland, and Scotland ; also in Vermont and other States in this country. Adhesive slate absorbs water readily, and is highly adhesive. Aluminous slate yields alum. Bituminous slate is impregnated with bitumen. Hornblende slate contains feldspar, and is used for flagging. Hones are made from slate, also pencils ; and the slate-clay which consists of silica and alumina is suitable for fire-brick. See Alum. Slicker — sometimes called "sleeker" and "smoother" — is a moulder's tool that usually has some special shape given to it on one side. The other side has a finger-piece or handle, by which means the slicker is worked upon the sand and made to impart smoothness and finish to the sur- face. These tools are of cast iron, brass, and steel, highly polished on the face side, and are known as corner, elbozv, pipe, button, flange, bead, and web slickers, etc. Consid- erable dexterity of hand and eye must be acquired before the moulder can use these tools creditably, and only the most skilled workmen should be allowed to use them indiscriminately. Inferior artists are apt to linger too long over the work, and their unpractised eye and lack of taste invariably end in producing lines that bear no resemblance Sling. 399 Smoothers. whatever to the original pattern; but on such parts as offer few difficulties they will smooth the surface with such frequency that the alumina in the sand is worked into a clayey skin on the surface, which, if it be not already loos- ened, will more than likely shrink and break away in scabs when the metal covers it. See Scabbed Castings. Sling. — A foundry device for handling and conveying flasks and loam-moulds. The stirrup-sling reaches from bot- tom lugs of a foundation-plate to the binders, or cross for binding the mould together, and serves the purpose of lifting the moulds also. Beam-slings are also stirrup, except that the lower end is usually made to fit the trunnion of a flask; by this means copes are reversed by simply lifting with one sling at each end of the beam. Chain-slings have stirrups, and are joined in pairs generally to one ring. The link- sling is simply a long welded link, and may be round, oval, or square ended. Rope-slings, being flexible, are extremely useful in the foundry. See Beam-slings; Rope-slings. Slip. — A common name for skinning-loam. See Skin- ning-loam. Smelting. — Fusing or melting the ores of metals, along with suitable fluxes, in order to separate the metallic part from the earthy, stony, and other parts. See Reduc- tion or Metals; Cast Ikon; Metals; Ores. Smelting Cast Iron.— See Cast Iron; Ores; Re- duction of Metals. Smelting-fnrnace. — The smel ting-furnace for iron is described at " Cast Iron " (q.v.). See also Ores. Smoothers. — Moulders' tools. See Slicker. Snap flask. 400 Snap- moulding. Snap-flask. — Besides the common snap-flask made at most foundries, there are some very excellent devices made for this purpose by the several patentees. One is an adjustable combination wood and metal snap-flask that can be adjusted to a variety of sizes. The wood parts of the flask are the pieces to which the hinge is attached, and also the parts to which the latch is fastened. The steel pieces are the inside lining. The wood and steel pieces are fas- tened together with bolts, and by means of a long slot the flask can be spread to the desired size. The wood is f-inch cherry, and the steel is |-inch. It is provided with a spring- latch, making it easy to open and close. Similar flasks are made all steel, having the same adjustment. Making them of the latter metal has suggested the round steel snap-flask, which is very light, and requires much less sand than the square one. For all who desire to manufacture their own snap-flasks, trimmings, including latches, hinges, and pins, can be had of infinite variety. Latches are made of mal- leable iron, with flat, oil-tempered steel spring. When the flask is closed the latch makes a solid locked corner, and it is so placed that by pulling latches together with finger and thumb of one hand, the flask opens freely. Hinges are made with the view of obviating any pinching of sand while closing. Any number of adjustable pins may also be had which can be perfectly fitted in a few moments. See Snap-moulder. Snap-moulding is bench-moulding; but instead of using the customary iron or wood flasks, the moulder is provided with a " snap-flask," inside of which he rams all his moulds, carrying them to the floor, when completed, one by one, in order for casting. When the snap is removed a flat weight holds it down. A hole in the weight permits the metal to be run down the sprue and pouring all off, independent of the usual surrounding flask. If the sand Snug. 401 Soapstone. walls are not able to withstand the pressure exerted when the mould is poured, a light iron band answering to the form of the snap is rammed within it. By this method the moulds are sustained like any other flasked ones, the differ- ence being that the light iron bands are not pinned to- gether. See Snap-flask; Bench-moulder. Snug. — An attachment cast to or bolted on flasks. Two or more snugs meet at the joint of the flask; one set has pins, the other holes to receive them, constituting a guide. See Lugs. Soap. — The alkalies used for soap-making are potash and soda. They must be in a caustic state, and this is pro- duced by dissolving them and passing the solution through newly slacked lime, which takes away the carbonic acid. In this caustic lye the fats are boiled, their glycerine set free, and the soap formed in a state of solution in the water. The soap is obtained in the solid form by boiling this solu- tion until the soap ceases to be soluble and rises to the surface, when it is drawn off into moulds. Castile-soap is composed of olive-oil and soda; oxide of iron is the cause of its mottled appearance. See Oils; Pans; Soap- kettle. Soap-kettle. — Some of the kettles for this purpose are covered in and provided with a large bend-pipe to re- ceive the vapors. The watery matter is condensed, and drawn off at the bottom ; the inflammable vapors are drawn under the fire. See Pans. Soapstone is steatite, and termed soapstone because of the smooth, greasy feel it has between the fingers. It is a hydrated silicate of magnesia — a massive variety of talc, which when pure and compact is highly refractory, and Socket pipe. 402 Sodium. suitable for furnace-linings and for the manufacture of fire-brick. Soapstone, ground very fine and mixed with carbon facings, makes an excellent material for coating the moulds of hollow ware and stove-plate castings, being espe- cially useful as a return-facing for printing with. See Be- TURN-FACING; PRINTING. Socket-pipe.— A water or gas pipe with a bell and spigot at its respective ends. The bell receives the spigot end of another pipe, with some clearance for lead or other packing with which to make a tight joint. A depression in the bell holds the packing, and the collar on the end of the spigot prevents the latter from slipping out. See Cast- iron Pipes. Soda. — A compound of oxygen and a metallic basis called sodium. It was formerly called mineral alkali, as it is found in mineral seams and crusts, and in great abun- dance in certain lakes in Egypt being brought thither by the water which enters from the neighboring country during the overflow of the Mle, and precipitated by evaporation during the dry season. Barilla is impure soda obtained by burning plants near the sea. Kelp is obtained by burning seaweed. For the purposes of com- merce, soda is obtained from common salt. See Salt ; Sodium. Sodium. — This is a very widely diffused and abundant element. As cliloride, it occurs in rock-salt, sea-water, salt-springs, and many mineral waters ; and as silicate, in many minerals. Metallic sodium was first discovered by Sir Humphry Davy. It is prepared in the same manner as potassium, requires the same measures for its preserva- tion, and exhibits properties similar to those of that metal. See Potassium : Salt : Soda ; Fluid Alloy. Soft-blast. 403 Softeners. Soft-blast. — The blast is termed "soft" when it is feeble and lacks force. A too low pressure of blast burns the fuel without melting at full duty, and below a certain amount of pressure the fuel would burn away, leaving the metal un melted. See Blower; Blast-pressure; Com- bustion. Soft -centre Steel. — Bar steel with a hard surface enclosing a tough centre core of mild or soft steel. This steel is used especially for making articles that, besides hav- ing a hard-tempered surface, must possess the strength of mild steel. The mild-steel ingot is cast, hammered down, and treated in the cementation-furnace until the surface has been carburized to the depth required, when it is again subjected to the process of rolling or hammering down to the size and shape of bar needed. See Cementation; Blister-steel. Softeners are a class of pig iron containing such soften- ing qualities as will destroy, or at least neutralize, opposite qualities existing in other irons ; or they may wholly con- sist of another metal to alloy with iron, as aluminum or aluminum ferro-silicons, etc. The softeniug elements in pig iron are graphitic carbon and silicon, while combined carbon, phosphorus, manganese, and sulphur maybe classed as hardeners. It is an established fact that all pig irons low in the latter elements, and which are at the same time high as to the former, are recognized as softeners, because of the remarkable quality of silicon to change chemically combined carbon to graphitic carbon ; in other words, changing hard iron to soft, and enabling the founder to use up large quantities of inferior irons, at reduced cost, by the simple admixture of another iron that costs no more than any other ordinary brand; and all this without any deteriorating effect on the resultant castings. See Scotch Pig Iron; Silicon; Analysis. Soft Pig Iron. 404 Solder. Soft Pig Iron. — This iron is usually termed gray pig iron, to distinguish it from the hard irons, which are lighter in color, even to whiteness. A chemical analysis of a really soft pig iron should exhibit about the following percentages of constituent elements : Graphitic carbon 3.36 per cent. Silicon 2.78 " Phosphorus 0.40 " Manganese . 0.40 " Sulphur 0.01 " Combined carbon 0.20 " Any addition over the quantities given, except for graphite and silicon, would tend to increase the hardness. See Gray Pig Iron; Softeners. Soft Solder. — One of the soldering alloys. See Solder. Solder. — Soldering is a process by which solid metallic substances are united by the intervention of a more fusible metal or solder, which, when placed between them and fused, unites the three parts into a solid mass; sometimes, however, the joining of two edges or surfaces may be ac- complished by fusing or melting with the same metal. Solders are made of gold, silver, copper, tin, lead, bismuth, etc. ; usually observing that in the composition there shall be some of the metal that is to be soldered, mixed with some higher and finer metals. The coppersmith's hearth, standing off from the wall, is a convenient fire for hard- soldering or brazing. The brazier's hearth is usually an iron plate with fire-box underneath ; a convenient aperture in the plate allows the heat to play direct on the work as it rests on the table, the force being regulated by a fan-blast. For fine and complicated soldering, the blowpipe is best; Solder. 405 Solder. the wind for which is sometimes obtained mechanically, but more commonly by blowing with the mouth. Jewelry manufacturers employ a trough or shoot of circular form, through which a gas flame is urged by means of a pair of ordinary bellows. The common blowpipe in the workshop is the oxyhydrogen, so arranged that it may be used at any desired angle. Silver solder is usually employed for fine work in brass, iron, or steel, and the brazing is effected by laying thin plates of the solder on the joints, which have been pre- viously moistened with borax and water. For gold and silver soldering, the borax is usually made into a creamy paste by rubbing with water and then painting over the parts to be joined. Solders of this class are often drawn into wire, but generally they are in thin plates, so that pieces of an exact size may be cut and laid over the work to be soldered. Before soldering or brazing can be successfully done, the joining surfaces must be made absolutely clean and smooth, and a suitable flux employed in order that the metal or metals will unite to the solder at a low temperature. The flux for steel ia, sal-ammoniac 1, borax 10— these in- gredients to be powdered together, fused, and pulverized ; for iron, borax or sal-ammoniac; for pewter, olive-oil ; for tinned iron, chloride of zinc or rosin; for lead and tin, rosin or sweet-oil; for copper and brass, chloride of zinc or sal-ammoniac ; for lead-pipe, tallow or rosin ; for zinc, chloride of zinc ; for spelter-solder, borax. Owing to the greater affinity of copper for zinc than for tin, some difficulty is usually experienced when zinc is to be soldered with the copper-bit or soldering-iron. This metal seems to remove the tin coating from the copper-bit, causing much trouble sometimes; but this maybe obviated by using the soldering fluid as a flux. The latter flux is an admirable one for nearly all other metals, and does not Solder. 406 Solder. necessitate that degree of cleanness so essential when other fluxes are employed. Soldering fluid is made by taking two ounces muriatic acid, add zinc till the bubbles cease to rise, then add one half-teaspoonful sal-ammoniac and two ounces water. Iron and steel may be soldered by using this fluid flux without any previous tinning. Gold is the solder for platinum, with borax for a flux. See Gold-ooldek. A good solder for iron is good tough brass, with borax for the flux. See Bra.ss. For the hammered -brass solder add a little chloride of potassium to the borax for a flux. Iron is soldered to steel or either to brass by applying in a molten state tin 3, copper 39£, zinc ?f parts. Cold-soldering (without fire) is done by using a mixture composed of bismuth \ ounce, quicksilver i ounce, block- tin filings 1 ounce, muriatic acid 1 ounce. Cold-brazing (without fire) : Brass-filings 2 ounces, steel- filings 2 ounces, fluoric acid J ounce. Place the filings in the acid and, when dissolved, apply the solution to the parts to be joined. Fluoric acid should be kept in lead or earthen vessels. Brass is readily soldered, in some cases, by first using sal-ammoniac as a flux and then placing a piece of tin-foil between the pieces and applying the hot iron until it melts. German silver is soldered by first applying the soldering fluid as a flux and using pewter solder with the blowpipe. When arsenic is mixed with solders it should be added at the last, taking care to avoid the fumes. When brass is employed as an ingredient it should be added after fusing the other metals, to avoid wasting the zinc. The following are the ingredients used for making solders in common use: Solids. 407 Solids. Pewter-solder Plumber's solder. Spelter-solder, for brass. Tinman's " Pewterer's soft solder . . . Zinc-solder Glazier's solder Black solder White solder for raised Bri- tannia-ware Hardening for Britannia ware Soft solder for Britannia ware Yellow solder for brass or copper Yellow solder for brass or copper, easily fused . . Bismuth-solder Solder for brass, to be ham- mered Brass-solder " " white Solder for steel joints Gold-solder " fine Silver-solder, hard soft Jewellers' solder, hard — " " medium " " softer . . Hard solder Spelter-solder for copper or iron 17.41 27.99 1 1 14.60 s pq 1-2 1 1 2 2 2 32 3 45 61£ 57.41 1 3 2 1 f 2 16 Solids. — Matter exists in three forms— solid, liquid, and gaseous. When the particles of a body cohere, as in ice, metals^ etc., so that they cannot move among them- selves, it is said to be a solid. All solids, except clay, are expanded by heat, but not equally. (See Expansion*.) Clay contracts in baking and ever afterwards remains so. Solids are melted by heat, and the process is termed lique- faction. A solid is firm and compact, and, unlike fluids, offers a sensible resistance to penetration and impression. See Fluids. Solid Shot. 408 Soot. Solid Shot.— See Hollow Shot. Solubility, or Solubleness, is the susceptibility of a body to being dissolved in a fluid. Solution is favored by whatever weakens cohesion. When the force of adhesion of the particles of a liquid for a solid exceeds the whole cohe- sive force of the latter, its cohesion is overcome and solution occurs, which means that the solid disappears and mixes uniformly with the liquid. See Satukatio^; Adhesion". Soluble Grlass. — This alkaline silicate, known as water-glass, liquid quartz, etc., was discovered by Prof. Fuchs of Munich, 1825. It has the property of solubility in water, and may while in that state be applied to glass painting, waterproofing materials, restoration of decaying stone buildings, and as a binding element in artificial stone. When the water has evaporated it leaves a hard, gelatinous, transparent glass, which is impervious to water or destructive atmospheric changes. Mixed with metallic oxides it is a good paint for frescos, and also for commoner purposes. The solution is obtained by fusing together pulverized quartz 15, potash 10, and pulverized charcoal 1. This mass when cold is crushed, and boiled for three hours in five times its weight of water, taking care to supply what is lost by evaporation. The result is a viscid mass, which must be preserved in well-stoppered vessels. The glass may be diluted to suit whatever purpose it is employed for. Solvent for Gold. — Mix equal parts of nitric and muriatic acids. See Gold; Aqua Regia. Soot is formed by the fuel which escapes combustion, and is composed principally of particles of carbon from a coal or wood fire. The lighter particles of ash are also mixed Sour Beer. 409 Specific Gravity. with it, as well as hydrocarbons from unburnt hydrocarbon vapors, and some ammoniacal salts. The latter qualities are what makes soot valuable as a manure. See Carbon. Sour Beer. — This unpleasant wash was formerly in great demand for hardening cores and mould surfaces. See Beer; Core-wash. Sow. — The heavy pig iron which has served as a leading channel from the spout of the blast-furnace, and which serves the purpose of a runner to the pigs when the tap is made. The pigs are forcibly separated from it immediately the iron has solidified. See Cast Iron ; Pig Iron. Spade. — See Shovel. Spanish Tutania. — If 8 ounces of iron or steel be melted with 16 ounces of antimony and 3 ounces of nitre, by adding the latter ingredients in small pieces after the steel is white hot a hardening is made, of which 1 ounce is sufficient to harden 8 ounces of tin. See Tutania. Spathic Iron Ore is the purest variety of clay iron- stone in which the metal occurs as a ferrous carbonate. A considerable proportion of the pig iron produced in England is smelted from these ores, the inferior grades of which constitute the clay ironstone and blackband iron- stone of the coal-measures. See Ores. Specific Gravity. — A term used to express the comparative weight of different substances. The specific gravity of a substance is the weight of a given bulk of it compared with the weight of an equal bulk of some other substance taken as a standard. The standard employed is a fixed one, being distilled water at a temperature of 60 Specific Gravity. 410 Specific Gravity. degrees. The weight of a cubic inch of silver is 10J times as much as the same measure of water; accordingly, the specific gravity of water being 1, that of silver is 10J. A cubic inch of cork weighs T 2 ¥ 4 g- as much as the same bulk of water; the specific gravity of cork, therefore, is f^ or .24. Mercury, water, and oil if thrown into a tumbler will arrange themselves in the order of their specific gravities: the mer- cury at the bottom, being the heaviest; then the water; on top of this the oil, being the lightest. Gases, like liquids, differ in their specific gravity. Smoke ascends, being lighter then air. Hydrogen is so much lighter than air that it will ascend with a loaded balloon. Contrary to this, because carbonic-acid gas is heavier than air, it remains at the bottom of wells, etc. A cubic inch of iron weighs 7£ times as much as a like bulk of water, and will therefore sink in the latter; but if hammered out into a vessel containing more than 7 J- cubic inches, the same iron will float, simply because it is lighter than an equal bulk of water. A floating substance displaces its own weight of liquid; and a body immersed in water loses as much weight as the water it displaces weighs. The specific gravity of a liquid is easily obtained in the following manner: Fill a glass vessel, whose weight is known, with water to a certain mark, and weigh it; sub- tract the weight of the vessel and you have the weight of the water alone. Then fill the vessel to the same height with the liquid in question, weigh it again, and subtract the weight of the vessel as before. To find its specific gravity divide its weight by that of the water. A simple way of finding the specific gravity of a solid would be to take a certain bulk, as a cubic inch or cubic foot, ascertain its weight, and divide it by a like bulk of water. There is difficulty, however, in obtaining any given bulk exactly, for which reason other methods are adopted. Specific Gravity. 411 Specific Gravity. If the solid sinks in water, weigh it first in air and then in water by means of a balance provided for the purpose. Divide its weight in air by the weight it loses in water, and the quotient will be its specific gravity. This is exactly the same as dividing the weight of the solid by that of an equal bulk of water, for it has been shown that a solid weighed in a liquid loses as much weight as the liquid it displaces weighs. A piece of platinum weighs 22 grains in air and 21 in water. If we divide 22 (its weight in air) by 1 (the loss of weight in water), we obtain 22 for the platinum's specific gravity. The specific gravity of a solid that floats on water is found by attaching something heavy enough to sink it. These are then weighed in air and in water, and the loss of weight in water found by subtraction, as before. In the same manner find how much weight the heavy body alone loses in water, and subtract this from the loss sustained by the two, which gives the weight of a volume of water equal to the body under examination. Divide the body's weight in air by this remainder, and the specific gravity is obtained. The specific gravity of gases is found by a similar process to that for liquids. The standard is air. A glass flask with stop-cock is weighed when full of air, and again when the air has been exhausted; the weight of the flask full of air is the difference between these weights. The flask is now filled with the gas in question, and again weighed; this weight, less that of the exhausted flask, is the weight of a flask full of the gas. Divide the weight of the gas by that of the air, and the quotient is the specific gravity required. If the specific gravity of a body is known, it is easy to discover how much any given bulk of it weighs. A cubic foot of Water weighs 1000 ounces, or 62 J pounds. The weight of a cubic foot of any given substance will therefore be equal to 62^ pounds multiplied by its specific gravity; as follows: What is the weight of a cubic foot of silver? The Specific- gravity Balance. 412 Speculum Metals. specific gravity of silver is 10.474. This multiplied into 62.5 gives 653.478 pounds, — the weight required. See Hydrostatic Balance; Weight of Metals. Specific-gravity Balance. — An instrument for finding the specific gravity of substances. The hydrometer or areometer is used for finding the specific gravity of fluids. Many kinds of these instruments are employed for this purpose, but they are all dependent on the principle that the weights required to immerse a light bulb of glass in different fluids are in proportion to the density of such fluids. See Specific Gravity; Hydrostatic Balance. Specular Iron. — Specular oxide of iron occurs crys- tallized in a great variety of forms. Some of these crystals have a polish like burnished steel; others are tarnished and appear of a red, blue, or yellow color. The most beautiful specimens come from Elba, where this iron is said to have been worked for three thousand years. Its composition is iron 69, oxygen 31. Speculum Metals are alloys of exceeding brittle- ness and hardness, and so brilliant when polished truly as to be used for the mirror-surface of reflecting telescopes. It is therefore called speculum metal. The quality of these alloys greatly deteriorates by a slight deviation to either side of the true atomic proportions. Their extreme brittleness necessitates great care in cooling castings made from them, so that nothing shall interfere to prevent all the parts cooling proportionately. Slow cooling in hot ashes acts beneficially by annealing the metal. As arsenic enters into the most of these mixtures, it is important that a good flux be employed to cause a perfect union with the other metals. One part nitre and two of tartar is a suitable flux for this purpose. The arsenic should Spelter. 413 Spider. be broken in fragments and tied in strong paper ; it may then be secured in the tongs and thrust under the surface — after which stir well and avoid the fumes. The follow- ing is a table of speculum alloys : SPECULUM ALLOYS. Hard, white " " better " " highly lustrous <« (< «< << Steel, hard Common Lord Rosse's Sir I. Newton's (yellow) . . . White (antimony mix.) " (withz\de; >> a u o o u > o a a a a CO Q H «j N