A Mathematical and Philosphical Dictionary
, from the Saxon æcre, or German acker, a field, of the Latin ager. It is a measure of land, containing, by the ordinance for measuring land, made in the 33d and 34th of Edward I, 160 perches or square poles of land; that is, 16 in length and 10 in breadth, or in that proportion: and as the statute length of a pole is 5 1/2 yards, or 16 1/2 feet, therefore the acre will contain 4840 square yards, or 43560 square feet. The chain with which land is commonly measured, and which was invented by Gunter, is 4 poles or 22 yards in length; and therefore the acre is just 10 square chains; that is, 10 chains in length and one in breadth, or in that proportion. Farther, as a mile contains 1760 yards, or 80 chains in length, therefore the square mile contains 640 acres.
The acre, in surveying, is divided into 4 roods, and the rood is 40 perches.
The French acre, arpent, is equal to 1 1/4 English acre;
The Strasburg contains about 1/2 an English acre;
The Welch acre contains about 2 English acres;
The Irish acre contains 1 ac. 2 r. 19 27/121 p. English.
Sir William Petty, in his Political Arithmetic, reckons that England contains 39 million acres: but Dr. Greve shews, in the Philos. Trans. N° 330, that England contains not less than 46 million acres. Whence he infers that England is above 46 times as large as the province of Holland, which it is said contains but about one million of acres.
By a statute of the 31st of Elizabeth, it is ordained, that if any man erect a cottage, he shall annex four acres of land to it.