ACRE (a word derived from the Saxon acere, a field) signified at first no determined quantity of land. It afterwards consisted of forty perches in length, by four perches in breadth, or 4840 square yards. The perch differed, however, in most counties; in some it was sixteen feet, in others eighteen feet, in others twenty feet, and in others twenty-four feet, and in others again it was twenty five feet. By the ordinance of measuring land, made 33 Ed. I., the acre was fixed by perches as it now exists; and by the statute 31 Elizabeth c.7, any person building a new cottage was compelled to lay thereto four acres of land after this measure. The Norman acre differed in size from the Saxon one.