Ex. A mixture of gold and silver weighed 170 lbs. and its specific gravity was 15630; hence h (by the table) c = 15630 C = 170 lbs. wherefore, by the rule, (1932615630) x 10744 39709824 134136660 × 170 X 170 = (19326 10744) × 15630 =296 × 170 = 50.32 lbs. of gold; consequently there will be 170 50.32 119.68 lbs. of silver. The weight of bodies-their magnitudes and also their quantities in a compound, may thus be found by means of a table of specific gravities; and for the more expeditious calculation in practice we add the following memoranda: 430.25 cubic inches of cast iron weigh one cwt., as also 397.60 of bar iron, 368-88 of cast brass, 352.41 of cast copper, and 372-8 of cast lead. 14.835 cubic feet of common paving stone weigh one ton, as also 14.222 of common stone, 13.505 of granite, 13.070 of marble, 64.46 of elm, 64 of Honduras mahogany, 51.65 of fir, 51.494 of beech, 42.066 of Spanish mahogany, and 36.205 of English oak. For wrought iron square bars, allow 100 inches in length of an inch square to a quarter of a cwt. A similar cast iron bar would require 9 feet in length for a quarter of a cwt. One foot in length of an inch square bar weighs 3 lbs. also the breadth and thickness being taken in, th of an inch, and the length in feet. length breadth x thickness X 7 144 = the weight Ex.-An iron bar 10 feet long, 3 inches broad, and 24 in avoirdupois pounds. For the weight of a cast iron pipe : The length being taken in feet, the diameter and thick ness of metal in inches, then we have 0.0876 × length x thickness X (inner diameter + thickness) the weight in cwts. = For a leaden pipe the rule is, 0.1382 length x thickness (inner diameter + thickness) the weight in cwts. = NOTE.-The weight of a cast iron pipe is to a leaden pipe of the same dimensions nearly as 7 is to 11. Ex.-If the inner diameter or bore of a cast iron pipe be 3 inches, and its thickness of an inch; what is the weight of 14 feet of it? •0876 × 14 × 1 × (3 + 1) =99645 cwt. = 3 qrs. 27 lbs. 9 oz. A leaden pipe is 12 feet long, the bore is 4 inches, and thickness of metal of an inch; therefore, •1382 × 12 × × (4 + 4) = 1·762 cwt.=1cwt. 3 qrs. 1 lb. For the weight of the rim of a fly-wheel. Let D be the diameter of the fly, exclusive of the rim, taken in inches; then take the difference of this and the diameter of the fly, including the rim, and call this difference d, T being the thickness of the rim of the fly, from side to side, then we have = •0073 x T x dx (D+ d) = the weight of the rim in cwts. Ex.-If the interior diameter of the fly be 100 inches D, half the difference of the exterior and interior diameter 5 = d, hence if the rim is 10 inches broad, as the exterior diameter will then be 110, and let the thickness of the rim be 4 inches = T, then, •0073 < 4 × 5 × (100 + 5) = 15·33 cwts. TABLE A. Of the weight of 1 lineal foot of Swedish iron, of all breadths and thicknesses, from 1 tenth of an inch to 1 inch, in pounds and decimal parts. •1 .2 .3 •4 •5.6 034068 101 135 169 203 237 270 ·304·338 473 541 608 676 ⚫2 811913 1.014 135203270 338 406 541 676 811 947 1.082 1.217 1.352 845 1.0141.183 1.352 1.521 1.690 1.2171.4201-623 1.826 2.029 1.657 1.893 2.1302-367 345 67 Of the weight of 1 lineal foot of Swedish iron, of all breadths and thicknesses, from 1 inch to 6 inches, in pounds and decimal parts. 1 | 12 | 13 | 13 2 2 33 4 5 6 in. 3.38 4.235.07 5.91 6.76 8.45 10-14 11.83 13.52 16.91 20-29 1 5.296-34 7.40 8.45 10.56 12.68 14.79 16.91 21.13 25.36 14 7-60 8.87 10-14 12.67 15.21 17.75 20-29 25-36 30-43 13 10-35 11-83 14-78 17.75 20.71 23.67 29-58 35-50 13 13.52 16.91 20.29 23.67 27-05 33.81 40-512 21.13 25-36 29.58 33.81 42.26 50-72 23 30.43 35.50 40.57 50-72 60.86 3 41-42 47-34 59-16 71.00 3}|| 54.10 67.62 81.14 4 84.52 101-44 5 121.72 6 TABLE C. Of the weight of 1 superficial foot of Swedish iron plate from 106th part of an inch thick to one inch. Of Multipliers for the other Metals, whereby their weights may be found from the above Tables. TABLE E. Table of the weight of one square foot of different n.etals in various thicknesses, in pounds and decimal parts. 1 2.535 2.486 2.345 2 5.070 4.972 4 5 7 8 2.860 2.738 3.693 4.690 5.720 5.476 7.386 3 7.605 7.458 7.035 8.580 8.214 11.079 10.140 9.944 9.380 11.440 10.952 14.772 12.675 12.130 11.725 14.300 13.690 18.465 6 15.216 14.916 14.670 17.160 16.428 22.158 17.851 17.402 16.415 20.020 19.166 25.851 20.280 19.888 18.760 22.880 21.904 29.544 9 22.815 22.774 21-105 25.740 24.642 | 33·237 10 25.350 24.260 23.450 28.600 27.380 36.930 11 27.885 26.746 25.795 31.460 30-118 40 623 12 30.410 29.232 28.140 34.320 32.856 44.316 13 32.945 31.718 30.485 37-180 35.594 48.009 14 35.480 34.204 32.880 40.040 38.332 51.702 15 38.015 36.690 35.225 42.900 41.170 55.405 16 40.550 39.176 37.570 45.760 43.908 59-098 TABLE F. Table of the weight of 1 foot in length of malleable Iron rod, from one-fourth to 6 inches diameter. Diam. Weight. Diam. Weight. Diam. Weight. •368 1금 9.2 330 29.82 4/2 62.21 ⚫654 2 10.47 1 11 1 1.02 1.47 2 2.61 11.82 3 13.25 3 14.76 16.36 12 18 14 3/8 |