GALLON (Imperial)

A unit of capacity in Great Britain containing four quarts, is used for both liquid and dry commodities, and is defined as the volume occupied by ten imperial pounds weight of distilled water, as weighed in air against brass weights with both water and air at 62° Fahrenheit, and the barometer at 30 inches (atmospheric pressure). It is equivalent to 4.5460 liters (277.420 U.S. cubic inches), or to 1.2003 U.S. gallons (defined below).