diameter of 181⁄2 inches, and a depth of 8 inches, and containing 2150.42 cubic inches. The Pound is the United States standard of weight as applied to general purposes, and is the weight of 27.7015 cubic inches of distilled water, at its greatest density (i. e. at 39° 83" Farenheit, the barometer being at 30 inches), and is equivalent to 7,000 Troy gr ins. (In some cases the following table for gross weight is used: 28 lb. 1 quar.; 4 quar. 1 cwt. ; 20 cwt., or 2240 lbs. 1 ton. TROY. Comparative Table of Weights. APOTHECARIES. AVOIRDUPOIS. 1 pound equals 5,760 grains. equals 5,760 gr ins, equals 7,000 grains. 1 ounce 480 175 pounds 480 66 66 437.5 Six quarts, The half peck, or dry gallon, contains 268 8 cubic inches. dry measure, are equal to nearly 7 quarts, liquid measure. Measures of Capacity. The following table will often be found convenient, taking inside dimensions: A box 24 in. x 24 in. x 14.7 will contain a barr1 of 311⁄2 gallons. A box 15 in. x 14 in. x 11 in. will contain 16 gallons. A box 84 in. x 7 in. x 4 in. will contain a gallon. A box 24 in. x 28 in. x 16 in. will contain 5 bushels. A box 16 in. x 12 in. x 11.2 in. will contain a bushel. A box 12 in. x 11.2 in. x 8 in. will contain a half bushel. A box 7 in. x 6.4 i. x 12 in. will contain a peck. A box 8.4 in. x 8 in. x 4 in. will contain a half peck, or 4 dry quarts. A box 6 in. x 5 3-5 in., and 4 in. deep. will contain a half gallon. A box 4 in. x 4 in., and 2 1-10 deep, will contain a pint. HAY MEASURE.-About 500 cubic feet of well-settled hay, or about 700 of new mown hay, will make a ton. To estimate amount of hay in mow -Ten cubic yards of meadow hay weigh a ton. When the hay is taken out of old stacks, 8 or 9 yards will make a ton. Eleven or 12 cubic yards of clover, when dry, weigh a ton. (Note-The only accurate method to measure hay is to weigh it, since two quantities equal in bulk will never weigh alike. Any rule is simply an approximation.) FLOOR, WALL AND ROOF MEASURE.-To find the number of square yards in a floor or wall: RULE-Multiply the length by the width or height (in feet), and divide the product by 9; the result will be square yards. 111⁄2 X106% Dimensions of One Acre. A square, whose sides are 12,649 rods, or 69.57 yards of 208.71 feet long, contains one acre. Table of dimensions of rectangle containing one acre: RODS. 2 X 80 3 X 53% 32X 45 5-7 22X 64 42 X 35 5-9 5 X 32 512 × 29 1-11 62 X 24 8-13 Estimates of Materials. 82X 18 14-17 192 X 15 5-21 122 X 12 4-5 12 13-20 X 12 13-20 31⁄2 ba rels of lime will do 100 square yards plastering, two coats. 8 X 20 barrel of plaster (stucco), will hard-finish 100 square yards 1 lastering. barrel of lime will lay 1,000 brick. (It takes good lime too it.) 1 cord rubble stone. 66 1 perch 66 (Estimating 4 c'd to perch.) To every barrel of lime estimate about 5% yards of good sand for plastering and brick work. Rules Relating to Hydraulic Prime Movers. Rule I. To calculate the gross power of a fall of water: To the actual head, add the height due to the velocity of water in the head-race. Multiply the sum by the volume of the flow of the water per second, and by the weight of water (62.4 lbs. per cu. ft.) The product will be the gross power in foot-lbs. per second. This divided by 550 equals the gross horse-power. Rule II. To find the net power of a fall of water. Multiply the gross power by the probable effi iency of the prime mover to be used. That efficiency ranges in Water pressure engines from.. Overshot and breast wheels.. Undershot wheels.... Turbine wheels..... .65 to .75 .70 to .80 .40 to .60 .60 to .80 To find the height of fall corresponding to a given velocity: Divide the half-square of the velocity by 32.2 (g). Amount of Paint Required for a Given Surface. It is impossible to give a rule that will apply n all cases, as the amount varies with the kind and thickness of the paint, the kind of wood or other material to which it is applied, the age of the surface, etc. The following is an approximate rule: Divide the number of square feet of surface by 200. The result will be the number of gallons of liquid paint required to give two coats; or, divide by 18 and the result will be the number of pounds of pure ground white lead required to give three coats. CIRCLES. Table showing the circumferences and areas of circles with diameters from 1 to 50 with sides of equal squares: The circumference of a circle is the diameter multiplied by 3.1415926+ and the area is equal to the circumference multiplied by one-quarter tie diameter; or, is equal to the diameter multiplied by .7854. These deci mals being too extended for common use, the above table is an approxi mate one, correct as far as the decimals are carried. |