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: -