Thus, the acre contains 4840 square yards, which is ten times a square of 22 yards in length and breadth. This 22 yards is the length which land-surveyors’ chains are made to have, and the chain is divided into 100 links, each ·22 of a yard or 7·92 inches. An acre is then 10 square chains. It may also be noticed that a square whose side is 69⁴/₇ yards is nearly an acre, not exceeding it by ⅕ of a square foot. 216. MEASURES OF SOLIDITY OR CAPACITY.[37] Cubes are solids having the figure of dice. A cubic inch is a cube each of whose sides is an inch, and so on. 1728 cubic inches are 1 cubic foot 1 c. ft. 27 cubic feet 1 cubic yard 1 c. yd. [37] ‘Capacity’ is a term which cannot be better explained than by its use. When one measure holds more than another, it is said to be more capacious, or to have a greater capacity. This measure is not much used, except in purely mathematical questions. In the measurements of different commodities various measures were used, which are now reduced, by act of parliament, to one. This is commonly called the imperial measure, and is as follows: MEASURE OF LIQUIDS AND OF ALL DRY GOODS. 4 _gills_ are 1 _pint_ 1 pt. 2 _pints_ 1 _quart_ 1 qt. 4 _quarts_ 1 _gallon_ 1 gall. 2 _gallons_ 1 _peck_[38] 1 pk. 4 _pecks_ 1 _bushel_ 1 bu. 8 _bushels_ 1 _quarter_ 1 qr. 5 _quarters_ 1 _load_ 1 ld. The gallon in this measure is about 277·274 cubic inches; that is, very nearly 277¼ cubic inches.[39] 217. The smallest weight in use is the grain, which is thus determined. A vessel whose interior is a cubic inch, when filled with water,[40] has its weight increased by 252·458 grains. Of the grains so determined, 7000 are a pound _averdupois_, and 5760 a pound _troy_. The first pound is always used, except in weighing precious metals and stones, and also medicines. It is divided as follows: [38] This measure, and those which follow, are used for dry goods only. [39] Since the publication of the third edition, the _heaped_ measure, which was part of the new system, has been abolished. The following paragraph from the third edition will serve for reference to it: “The other imperial measure is applied to goods which it is customary to sell by _heaped measure_, and is as follows: 2 gallons 1 peck 4 pecks 1 bushel 3 bushels 1 sack 12 sacks 1 chaldron. The gallon and bushel in this measure hold the same when only just filled, as in the last. The bushel, however, heaped up as directed by the act of parliament, is a little more than one-fourth greater than before.” [40] Pure water, cleared from foreign substances by distillation, at a temperature of 62° Fahr. AVERDUPOIS WEIGHT.