General Data

Pure water is a colorless, tasteless, odorless, limpid fluid, that is practically incompressible; for each atmosphere of pressure it sustains it is compressed only 47 1/2 millionths of its bulk. It is a chemical combination of oxygen and hydrogen in the proportions of 88.9 parts by weight of oxygen to 11.1 parts of hydrogen, or 1 volume of oxygen to 2 volumes of hydrogen. Its weight varies with its temperature; at 62°F., which is taken as the average temperature, 1 cubic foot weighs 62.355 pounds.

For ordinary calculations, the weight is taken in round numbers at 62.5 pounds per cubic foot: when greater precision is required, it is taken at 62.4 pounds per cubic foot, its weight at 52.30 F.

The gallon is the unit of measure for water. One gallon of water measures. 134 cubic feet, contains 231 cubic inches, and at 620 F. weighs about 8 1/3 pounds. The United States gallon differs from the British or Imperial gallon, with which it should not be confused. A comparison of the American and Imperial gallon may be found in the following table:

Table XII - Weight And Capacity Of Different Standard Gallons Of Water

Notable Temperature

There are four notable temperatures for water, viz.:

The weight of one cubic foot of water at the four notable temperatures may be found in the following table:

Table XIII - Weight Of Water

The following factors are useful for changing given quantities of water from one denomination to another:

1 cubic foot contains 1,728 cubic inches.

1 cubic foot contains 7.485 United States gallons, which, in ordinary calculations, is taken as 7.5 gallons.