Gallon

Gallon, the standard unit of measure for liquids throughout the United Kingdom. It has existed as a measure from the earliest times, and in consequence has undergone many changes. The oldest exchequer standards preserved in the Standards Office include a Winchester corn gallon, of a capacity of 274½ cubic inches, constructed by order of Henry VII.; Queen Elizabeth added a standard ale gallon in 1601 of 282 cubic inches, and Queen Anne added in 1707 a standard wine gallon of 231 cubic inches. All these standard measures, however, were abolished in 1824, when the present imperial gallon, containing 10 lb. of distilled water, weighed in air (the barometer being at 30 inches, and the thermometer at 62° F.), was made the standard of capacity for liquid measures. This gives 277.274 cubic inches. The United States gallon is that of 231 inches, so that 59 imperial gallons are equal to 71 United States standard gallons. See WEIGHTS AND MEASURES.