ACRE

ACRE, a measure of superficies, and the principal denomination of land-measure in use throughout the whole of Great Britain. The word (formed from the Saxon acher, or the German aker, a field) did not originally signify a determinate quantity of land, but any open ground, especially a wide campaign; and in this antique sense it seems to be preserved in the names of places, as Castle-acre, West-acre, &c. The English standard acre, now the imperial acre of Britain, is formed by raising a square of which the basis is the chain of 66 feet, or 22 yards, or 1/80th of a mile; and ten of these squares form the acre, which thus contains 4840 square yards. This is divided into roods, of which there are four in the acre; and into poles or perches, of which there are 40 in each rood, or 160 in the acre. The rood will thus measure 1210 square yards, and the pole 30 1/2 square yards, according to the following table, which contains also other denominations useful to be compared with the acre.

The above is the standard acre of England; but various customary acres are in use throughout the different counties, deviating considerably from this standard both in excess and defect, though all of them are now illegal since the act 5 George IV., which establishes the same standard throughout the whole kingdom. In Bedfordshire, it is sometimes only two roods; Cheshire, formerly, and still in some places, 10,240 square yards; Cornwall, sometimes 5760 yards; Dorsetshire, generally 134 perches; Hampshire, from 107 to 120 perches, but sometimes 180; Herefordshire, two-thirds of a statute acre. The acre for hops contains 1000 plants, and is only equal to half a statute acre; for wood, again, it is 256 perches. Leicestershire, 2308 1/2 square yards; Lincolnshire, five roods, particularly for copyhold land; Staffordshire, nearly 2 1/2 acres; Sussex, 107, 110, 120, 130, or 212 perches; the short acre 100 or 120 perches, the forest acre 180 perches. Westmoreland, 6760 square yards, or 160 perches of 6 1/2 yards square; in some parts the Irish acre is used: Worcester, the hop acre, of 1000 stocks, 90 perches, sometimes 132 or 141 perches.

In North Wales, the Erw or true acre is 4320 square yards, the Stang or customary acre 3240 square yards, as in Anglesea and Caernarvonshire, making 5 1/2 llathen, = 160 perches of 4 1/2 yards square, called paladr; 8 acres make an ox-land, and 8 of these a plough-land, in Pembrokeshire. In South Wales the Erw varies greatly with the perch; sometimes this is nine feet square, 160 perches making one stangell, and four stangells one erw of 5760 yards; sometimes 10 1/2 feet square, making a quart or quarter of a llath, 40 of which make a stangell, and four stangells an erw, which is thus 7840 yards, equal to the Irish acre; sometimes 11 feet, called bat or eglwys haw, making the erw 9384 yards, as in Glamorganshire, one-fifth more = 11,261 yards; sometimes 11 1/2 feet, called a llath, 48 making a quarter cyvar, and four cyvars an erw of 11,776 yards; lastly, 12 feet, giving an erw of 10,240 yards, equal to the Staffordshire acre.

Nothing can show more clearly than the existence of such numerous and useless diversities, the necessity of the late act for establishing a uniform standard throughout Great Britain, and which only requires to be enforced with strictness to abolish for ever every other measure. In Scotland the acre is much more uniform, scarcely deviating in any part more than one per cent. from the standard. It is raised from the chain of 24 ells; and by the verdict of the jury assembled at Edinburgh on the 4th February 1826, to determine the proportion between the existing measures and the imperial, the ell was found, according to an accurate measurement made by Mr Jardine, civil engineer, 37.0598 inches, making the chain 74.1196 feet, and the acre 6104 square yards and .12789, &c. decimals of a yard. It is considerably larger, therefore, than the imperial acre; and as the act of uniformity establishes this latter in its stead, it makes an important change throughout Scotland, and it becomes necessary to know exactly the proportions between them. The imperial, we have seen, contains 4840 square yards, while the Scottish contains 6104.12789, &c. They are to each other, therefore, as 1 is to 1.26118345; so that 1000 acres Scottish are equal to 1261.18345 imperial; and in every case, to convert Scottish into imperial, multiply by the fraction 1.26118345: such minuteness, however, is seldom required in practice. A ready and very accurate approximation will be obtained by reckoning one acre Scottish equal to five quarters imperial, and 1/24th part more. This will give the value of the acre almost to one-fourth of a square yard in defect. Hence we have this general rule: To convert Scottish acres into imperial, add one-fourth; and if that is not sufficiently minute, add 1/24th more. Take, for example, 1000 acres, add one-fourth or 250, and we have 1250; add still 1/24th, or 11, and we have 1261. This rule is obtained by expressing the above fraction in a series of which we take only the first three terms. It is one acre Scottish = $1\; +\; \backslash frac\{1\}\{4\}\; +\; \backslash frac\{1\}\{96\}\; +\; \backslash frac\{1\}\{2304\}$, &c. acres imperial. By a similar rule, it is easy to convert the Scottish money rates or prices of land into imperial: we have only to multiply the Scottish prices by the fraction 0.792906, the reciprocal of the other; or deduct one-fifth from the price, and for greater accuracy 1/24th more; or what is still simpler, deduct 20 1/2 per cent. or 4s. 1 1/2d. in the pound from the Scottish prices. An estate of 1000 acres, for example, is to be let at 30s. per acre: What is the rent per imperial acre? Deduct 4s. 1 1/2d. and the half of it for the additional 10s., and we have 6s. 2 1/2d. less, or on the whole 23s. 9 1/2d. These rules will apply in every practical case; and for very particular and extremely accurate purposes, recourse must be had to the original fraction 0.792906 and 1.26118345.

Such are the relations of the Scottish standard acre to the imperial; but until of late years, it was the practice of land-surveyors to measure with a chain of 74 feet and 4-10ths of

Acre
Acrido-
phagi.

a foot in length, the length of the ell having been erroneously estimated at 37 inches and 2-10ths of an inch. This practice increased the acre from 6104-13448 to 6150-4 square yards; it made the ratio of this acre to the imperial as 1 to 1-27074, &c.; or we may reckon one acre equal to five quarters imperial, and $\backslash frac\{1\}\{2\}$th more.

When this error in the length of the chain came to be discovered, surveyors took to the chain of exactly 74 feet; this length being recommended by the round number, and the nearer approach to the standard. By it the acre contains only 6084-4444, &c. yards; it is to the imperial acre as 1 to 1-25711662, &c. or we make one of these acres equal to five quarters imperial, and $\backslash frac\{1\}\{2\}$th more.

In Ireland the perch, of which the acre contains as usual 160, is a square of seven yards. The acre, therefore, contains 7840 square yards. See WEIGHTS AND MEASURES; Parliamentary Reports of the Commissioners of Weights and Measures; Act 5 Geo. IV.; and Buchanan's Tables of Weights and Measures, where the conversions are all given by inspection. (G. B.)

The following table contains the principal foreign land measures, with their equivalents in Imperial measurement.

In the United States of America the imperial acre is used. The Roman jugerum was somewhat larger than half an imperial acre, containing 2 roods, 19 perches, 189 square feet. Two jugera formed a heredium, so called from its being the quantity of land originally assigned to each Roman citizen; a hundred heredia formed a centuria, and four centuriae a saltus. The Greek plethron consisted of 4 arura, and was equal to 37 perches, 153 square feet.