In square-built tanks the length by width by depth equals cubic contents. Each cubic foot by 6 1/4 equals number of gallons in tank. Thus a tank measuring 6 ft. long, 3 ft. wide, and 4 ft. deep contains 72 cub. ft., and 72 x 6 1/4 = 450 gal. = 4500 lb.

The following table gives the more exact number of gallons in square tanks, according to their dimensions - 1 gal. of water being reckoned at

6.232 lb.: -

## Number Of Gallons In Square-Built Tanks

 Size of Tank. Depth in Feet. Feet. 3 ft. 4 ft. 5 ft. 6 by 3 336 448 560 6 „ 4 448 598 747 6 „ 5 560 747 934 6 „ 6 673 897 1121 7 „ 4 523 698 870 7 „ 5 654 872 1090 7 „ 6 785 1047 1308 7 „ 7 916 1221 1526 8 „ 4 598 797 997 8 „ 5 747 997 1246 8 „ 6 897 1196 1495 8 „ 7 1046 1395 1744 8 „ 8 1196 1595 1994 9 „ 5 841 1121 1402 9 „ 6 1009 1346 1682 9 „ 7 1177 1570 1963 9 „ 8 1346 1794 2243 9 „ 9 1514 2019 2523 10 „ 5 934 1246 1558
 Size of Tank. Depth in Feet. Feet. 3 ft. 4 ft. 5 ft. 10 by 6 1121 1495 1869 10 „ 7 1308 1744 2181 10 „ 8 1495 1994 2492 10 „ 9 1682 2243 2804 10 „ 10 1869 2492 3116 11 „ 6 1233 1645 2056 11 „ 7 1439 1919 2399 11 „ 8 1645 2193 2742 11 „ 9 1850 2467 3084 11 „ 10 2056 2742 3427 11 „ 11 2262 3016 3770 12 „ 6 1346 1794 2243 12 „ 7 1570 2093 2617 12 „ 8 1794 2393 2991 12 „ 9 2019 2692 3365 12 „ 10 2243 2991 3739 12 „ 11 2467 3290 4113 12 „ 12 2692 3589 4487

To find the contents in gallons of circular tanks or wells it is necessary to square the diameter, multiply by the depth, and then multiply the result by 4'8947. Thus, a circular tank with a diameter of 4 ft. and a depth of 3 ft. would be measured thus: The diameter squared = 4 x 4 = 16. This multiplied by the depth = 16 x 3 = 48; and 48 x 48947 = 234.946 or say 235 gal.

The volume in cubic feet of a cylindrical tank, prism, or parallelepiped equals area of the base by height or depth. The area of the base equals the diameter squared x .7854. Therefore the volume of a circular tank with a diameter of 4 ft. and a depth of 3 ft. is found thus: Area of base = 4 x 4 x .7854 = 125664 sq. ft. Volume = 125664 sq. ft. x 3 ft. = 37.6992 cub. ft. Reckoning each cubic foot equals 6 1/4 gal. of water, the number of gallons in the tank = 37.6992 x 6.25 = 23662 gal. The following table gives the number of gallons contained in circular tanks or wells of various dimensions: -