Quarter (unit)

The quarter (lit. "one-fourth") is used as the name of several distinct English units based on ¼ sizes of some base unit.

The "quarter of London" mentioned by the Magna Carta as the national standard measure for wine, ale, and grain was ¼ ton or tun. It continued to be used, e.g., to regulate the prices of bread. This quarter was a unit of 8 bushels of 8 gallons each, understood at the time as a measure of both weight and volume: the grain gallon or half-peck was composed of 76,800 (Tower) grains weight; the ale gallon was composed of the ale filling an equivalent container; and the wine gallon was composed of the wine weighing an equivalent amount to a full gallon of grain.

In measures of length, the quarter (qr.) was ¼ of a yard, formerly an important measure in the cloth trade. 3 qr. was a Flemish ell, 4 quarters were a yard, 5 qr. was an (English) ell, and 6 qr. was an aune or French ell. Each quarter was made up of 4 nails. Its metric equivalent was formerly reckoned as about 0.228596 m, but the International Yard and Pound Agreement set it as 0.2286 exactly in 1959.

In measures of weight and mass at the time of the Magna Carta, the quarter was ¼ ton or (originally) 500 pounds. By the time of the Norman French copies of the c. 1300 Assize of Weights and Measures, this had changed to 512 lbs. These copies describe the "London quarter" as notionally derived from 8 "London bushels" of 8 wine gallons of 8 pounds of 15 ounces of 20 pence of 32 grains of wheat, taken whole from the middle of an ear; the published Latin edition omits the quarter and describes corn gallons instead.

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