and ductile, but its tenacity is such that it can be drawn into wire with great difficulty. Tensile strength, 1600 to 2400 lbs. per square inch. Its elasticity is very low, and the metal flows under very slight strain. Lead dissolves to some extent in pure water, but water containing carbonates or sulphates forms over it a film of insoluble salt which prevents further action. Magnesium, Mg.-At. wt. 24. Sp. gr. 1.69 to 1.75. Silver-white, brilliant, malleable, and ductile. It is one of the lightest of metals, weighing only about two thirds as much as aluminum. In the form of filings, wire, or thin ribbons it is highly combustible, burning with a light of dazzling brilliancy, useful for signal-lights and for flash-lights for photographers. It is nearly non-corrosive, a thin film of carbonate of magnesia forming on exposure to damp air, which protects it from further corrosion. It may be alloyed with aluminum, 5 per cent Mg added to Al giving about as much increase of strength and hardness as 10 per cent of copper. Cubical expansion by heat 0.0083, from 32° to 212° F. Melts at 1200° F. Specific heat .25. Manganese, Mn.--At. wt. 55. Sp. gr. 7 to 8. The pure metal is not used in the arts, but alloys of manganese and irou, called spiegeleisen when containing below 25 per cent of manganese, and ferro-manganese when containing from 25 to 90 per cent, are used in the manufacture of steel. Metallic manganese, when alloyed with iron, oxidizes rapidly in the air, and its func tion in steel manufacture is to remove the oxygen from the bath of steel whether it exists as oxide of iron or as occluded gas. Mercury (Hydrargyrum), Hg.-At. wt. 199.8. A silver-white metal, liquid at temperatures above-39° F., and boils at 680° F. Unchangeable as gold, silver, and platinum in the atmosphere at ordinary temperatures, but oxidizes to the red oxide when near its boiling-point. Sp. gr.: when liquid 13.58 to 13.59, when frozen 14.4 to 14.5. Easily tarnished by sulphur fumes, also by dust, from which it may be freed by straining through a cloth. No metal except iron or platinum should be allowed to touch mercury. The smallest portions of tin, lead, zinc, and even copper to a less extent, cause it to tarnish and lose its perfect liquidity. Coefficient of cubical expansion from 32° to 212° F. .0182; per deg. .000101. Nickel, Ni.-At. wt. 58.3. Sp. gr. 8.27 to 8.93. A silvery-white metal with a strong lustre, not tarnishing on exposure to the air. Ductile, hard, and as tenacious as iron. It is attracted to the magnet and may be made magnetic like iron. Nickel is very difficult of fusion, melting at about 3000 F. Chiefly used in alloys with copper, as german-silver, nickel-silver, etc., and recently in the manufacture of steel to increase its hardness and strength, also for nickel-plating. Cubical expansion from 32° to 212° F., 0.0038. Specific heat .109. Platinum, Pt.-At. wt. 195. A whitish steel-gray metal, malleable, very ductile, and as unalterable by ordinary agencies as gold. When fused and refined it is as soft as copper. Sp. gr. 21.15. It is fusible only by the oxyhydrogen blowpipe or in strong electric currents. When combined with iridium it forms an alloy of great hardness, which has been used for gunvents and for standard weights and measures. The most important uses of platinum in the arts are for vessels for chemical laboratories and manufactories, and for the connecting wires in incandescent electric lamps. Cubical expansion from 32° to 212° F., 0.0027, less than that of any other metal except the rare metals, and almost the same as glass. Silver (Argentum), Ag.-At. wt. 107.7. Sp. gr. 10.1 to 11.1, according to condition and purity. It is the whitest of the metals, very malleable and ductile, and in hardness intermediate between gold and copper. Melts at about 1750° F. Specific heat .056. Cubical expansion from 32° to 212° F., 0.0058. As a conductor of electricity it is equal to copper. As a conductor of heat it is superior to all other metals. Tin (Stannum) Sn.-At. wt. 118. Sp. gr. 7.293. White, lustrous, soft, malleable, of little strength, tenacity about 3500 lbs. per square inch. Fuses at 442° F. Not sensibly volatile when melted at ordinary heats. Heat conductivity 14.5, electric conductivity 12.4; silver being 100 in each case. Expansion of volume by heat .0069 from 32° to 212° F. Specific heat .055. Its chief uses are for coating of sheet-iron (called tin plate) and for making alloys with copper and other metals. Zinc, Zn.-At. wt. 65. Sp. gr. 7.14. Melts at 780° F. Volatilizes and burns in the air when melted, with bluish-white fumes of zinc oxide. It is ductile and malleable, but to a much less extent than copper, and its tenacity, about 5000 to 6000 lbs. per square inch, is about one tenth that of wrought iron. It is practically non-corrosive in the atmosphere, a thin film of carbonate of zinc forming upon it. Cubical expansion between 32° and 212° F., 0.0088. Specific heat .096. Electric conductivity 29, heat conductivity 36, silver being 100. Its principal uses are for coating iron surfaces, called galvanizing," and for making brass and other alloys. 46 WEIGHT OF RODS, BARS, PLATES, TUBES, AND = external Sectional areas of square bars = s2; of flat bars = bt; of round rods = .7854d2; of tubes = .7854(d2 d12) = 3.1416(dt t2). Volume of 1 foot in length: of square bars = 1282; of flat bars = 12bt; of round bars = 9.4248d2; of tubes = 9.4248(d2 — d12) = 37.699(dt-t2), in cu. in. Weight per foot length = volume weight per cubic inch of the material. Weight of a sphere = diam.3 X .5236 × weight per cubic inch. 7.218 450. 37.5 312 31bt.2604 15-16 2.454d2.1363d 7.7 480. 40. 3382 3gbt .2779 1. 2.618d2.1455d 7.854 489.6 40.83.4s2 3.4bt .2833 1.02 2.670d2.1484d 8.855 552. 46. 3.83382 3.833bt.3195 1.15 3.011d2.1673d% 8.393 523.2 43.6 3.633s23.633bt.3029 1.09 2.854d2.1586ds .4106 1.48 3.870d2.2150d .0963 0.347 0.908d2.0504ds .0945 0.34 0.891d2.0495ds .0174 1-16 0.164d2.0091ds Weight per cylindrical in., 1 in. long, coefficient of d2 in ninth col. ÷ 12. For tubes use the coefficient of d2 in ninth column, as for rods, and multiply it into (d2-d12); or multiply it by 4(dt-12). For hollow spheres use the coefficient of d3 in the last column and multiply it into (d3-d13). For hexagons multiply the weight of square bars by 0.866 (short diam. of hexagon-side of square). For octagons multiply by 0.8284. MEASURES AND WEIGHTS OF VARIOUS MATERIALS (APPROXIMATE). Brickwork.-Brickwork is estimated by the thousand, and for various thicknesses of wall runs as follows: 814-in. wall, or 1 brick in thickness, 14 bricks per superficial feet. 1234 17 2111⁄2" 1% 212 66 66 An ordinary brick measures about 84 X 4 X 2 inches, which is equal to 66 cubic inches, or 26.2 bricks to a cubic foot. The average weight is 4 lbs. Fuel. A bushel of bituminous coal weighs 76 pounds and contains 2686 cubic inches = 1.554 cubic feet. 29.47 bushels 1 gross ton. = A bushel of coke weighs 40 lbs. (35 to 42 lbs.). One acre of bituminous coal contains 1600 tons of 2240 lbs. per foot of thickness of coal worked. 15 to 25 per cent must be deducted for waste in mining. = 1 ton, 2240 lbs. 41 to 45 cubic feet bituminous coal when broken down...... = 1 ton, 2240 lbs. 34 to 41 anthracite, prepared for market.. of charcoal. "coke.. 123 70.9 66 46 66 66 66 66 ...... 1 ton, 2240 lbs. 1 cubic foot of anthracite coal (see also page 625).................... Cumberland coal........... Cannel coal.. 1 66 66 66 bituminous " 66 charcoal (hardwood). ................ ..................... = 1 ton, 2240 lbs. =55 to 66 lbs. =50 to 55 lbs. = 53 lbs. = 50.3 lbs. = 18.5 lbs. = 18 lbs. A bushel of charcoal.-In 1881 the American Charcoal-Iron Workers' Association adopted for use in its official publications for the standard bushel of charcoal 2748 cubic inches, or 20 pounds. A ton of charcoal is to be taken at 2000 pounds. This figure of 20 pounds to the bushel was taken as a fair average of different bushels used throughout the country, and it has since been established by law in some States. Ores, Earths, etc. 13 cubic feet of ordinary gold or silver ore, in mine.. Cement.-English Portland, sp. gr. 1.25 to 1.51, per bbl.... 400 to 430 lbs. Rosendale, U. S., a struck bushel. Lime.-A struck bushel... 62 to 70 lbs. 72 to 75 lbs. › Grain.-A struck bushel of wheat = 60 lbs.; of corn = 56 lbs. ; of oats = 30 lbs. Salt.-A struck bushel of salt, coarse, Syracuse, N. Y. = 56 lbs.; Turk's Island 76 to 80 lbs. Rounds: 14 to 1% inches, advancing by 16ths, and 1% to 5 inches by 8ths. Squares: 5/16 to 14 inches, advancing by 16ths, and 14 to 3 inches by 8ths. Half rounds: 7/16, %, 5%, 11/16, 34, 1, 116, 114, 1%, 14, 2 inches. Ovals: 4, 5% × 5/16, 34 × %, % × 7/16 inch. Half ovals: 2 × %, % X 5/32, 34 X 3/16, % × 7/32, 11⁄2 x 1⁄2, 13⁄4 × %, 1% 5% inch. Round-edge flats: 11⁄2 x 1⁄2, 134 × 5%, 1% X 5% inch. Bands:% to 1% inches, advancing by 8ths, 7 to 16 B. W. gauge. 14 to 5 inches, advancing by 4ths, 7 to 16 gauge up to 3 inches, 4 to 14 gauge, 34 to 5 inches. WEIGHTS OF SQUARE AND ROUND BARS OF WROUGHT IRON IN POUNDS PER LINEAL FOOT. Iron weighing 480 lbs. per cubic foot. For steel add 2 per cent. |