GALLON, the standard measure for liquids and dry goods throughout the United Kingdom. It has existed as a measure from the earliest times, and, in consequence, has undergone many changes. lu the time of Henry III., it was enacted that the G. should oe 8 lbs. of 12 ozs. each, an ounce being the weight of 640 dry grains of wheat from the middle of the ear.
In 1650, there wire three distinct G. measures—viz., (1) the G. measure in common use, which contained about 231 cub. in.: (2) the customary standard at the guildhall, which, though not a legal standard, was frequently referred to as such, even by the law-officers of the crown; and though generally estimated at 231 cub, in., in reality contained only 224: (3) there was also the legal standard measure, preserved at the treasury, which contained 282 cub. inches.
Besides these three, there was another G. measure frequently employed for measur ing corn, called the Winchester gallon. This measure, though directed in William M.'s reign to contain 269 cub. in., was soon afterwards changed to 272i cub. iu., at which
value it remained for a long period.
In 1706, the G. of 231 cub, in. was made the standard wine gallon.
These measures were gradually changed in value, and appropriated to the measure ment of particular substances, till, in 1825, just before the passing of the " act for ascertaining and establishing uniformity of weights and measures," they stood thus: In old dry or corn measure, the gallon= 268.6 cubic inches.
In old Wine measure, " " = 230.85 " In old ale and beer measure, " " = 282 In Jan., 1826, when the above-mentioned act came into operation, all these measures were abolished, and it was enacted that the standard measure of capacity for all liquids and for dry goods not measured by heaping, shall be a G. containing 10 lbs. ay. of tilled water, weighed in air (the barometer being at 30 in., and the thermometer at 62°). This gives 277.274 cub. in. for the imperial 4., and by subdivision or multiplication of this standard, the other measures can easily be found. See MEASURES.