Dry gallon (exactly ). Dry gallon The dry gallon, also known as the corn gallon or grain gallon, is a historic British dry measure of volume that was used to measure grain and other dry commodities and whose earliest recorded official definition, in 1303, was the volume of 8 pounds of wheat. It is not used in the US customary system – though it implicitly exists since the US dry measures of bushel, peck, quart, and pint are still used – and is not included in the handbook that many states recognize as the authority on measurement law. The fluid gallon is
Gallon one time defined as the volume of a cylinder 6 inches deep and 7 inches in diameter, i.e. . It had been redefined during the reign of Queen Anne, in 1706, as 231 cubic inches exactly, which is the result of the earlier definition with π approximated to . Although the wine gallon had been used for centuries for import duty purposes there was no legal standard of it in the Exchequer and a smaller gallon was actually in use, so this statute became necessary. It remains the US definition today. In 1824, Britain adopted a close approximation to the