1911 Encyclopædia Britannica/Acre (land measure)
ACRE, a land measure used by English-speaking races. Derived from the Old Eng. acer and cognate with the Lat. ager, Gr. άγρός, Sans. ajras, it has retained its original meaning “open country,” in such phrases as “God’s acre,” or a churchyard, “broad acres,” &c. As a measure of land, it was first defined as the amount a yoke of oxen could plough in a day; statutory values were enacted in England by acts of Edward I., Edward III., Henry VIII. and George IV., and the Weights and Measures Act 1878 now defines it as containing 4840 sq. yds. In addition to this “statute” or “imperial acre,” other “acres” are still, though rarely, used in Scotland, Ireland, Wales and certain English counties. The Scottish acre contains 6150.4 sq. yds.; the Irish acre 7840 sq. yds.; in Wales, the land measures erw (4320 sq. yds.), stang (3240 sq. yds.) and paladr are called “acres”; the Leicestershire acre (23083 sq. yds.), Westmoreland acre (6760 sq. yds.) and Cheshire acre (10,240 sq. yds.) are examples of local values.