WEIGHT, in commerce, denotes a body of a known weight, appointed by law to be the standard of comparison between different quantities of merchandise of certain descriptions ; the weight itself being usually of lead, iron, brass, or other metal.
The great diversity of weights and measures, in all nations, for ditlereitt kinds of commodities, has always been a just subject of regret and complaint ; being the cause of various disputes and deceptions, which it is almost impossible to avoid under present circumstances. And it is therefore much to be wished, though perhaps little to be expected, that one uni f win system of weights should be adopted as applicable to all kinds of substances ; an attempt at which was made in France during the revolution, but which was afterwards laid aside by an imperial decree, in consequence of the repeated remonstrances of people in trade; so difficult is it to over come prejudices and customs long established, however advantageous the change may be when properly understood.
In the reign of king Richard I. it. was ordained, that there sin mid be only one weight and one measure throughout Eng land; and in the Phil. Trans. No. 458, p. 457, we„tind an account of the analogy between English weights and mea sures drawn up by _Mr. 13arlow ; in which he states, that anciently the cubic foot of water was assumed as a general standard fin. all liquids. This cubic foot, of 621 lb. multiplied by 32, gives 2000 lb. the weight of a ton ; and hence S cubic feet of water made a hogshead. and 4 hogsheads a tun, or ton, in capacity and denomination, as well as weight.
Dry measures were raised on the same model. A bushel of wheat, assumed as a general standard for ail sorts of grain, also weighed 621 lb. Eight of these bushels make a quar ter; and 4 quarters, or 32 bushels, a ton. Coals were like wise sold by the chaldron, supposed to weigh a ton, or 2000 lb., though in reality it probably weighs upwards of 3000 lb.
This principle, though not sufficiently accurate in some cases, was extremely obvious, and might have been improved so as to ansm er all the purposes of commerce ; but unfo• tunately, instead of rendering it more simple, it has been made infinitely more complicated by the different weights since introduced.
.Modern European TFeights.-1. English weights. By the twenty-seventh chapter of ilay na Ghana, the weights all over England are to be the same ; but for different com modities there are two different sorts, viz. : Troy weight and Avoirdupois weight. The origin from which they are both raised is, a grain of wheat gathered in the middle of the ear.
In Troy weight, 24 of these grains make 1 pennyweight sterling; 20 pennyweights make I ounce ; and 12 ounces 1 pound.
By this weight we weigh gold, silver, jewels, and liquors. The apothecaries also use the Troy pound, ounce, and grain : but they divide the ounce into S drachms, the drachm into 3 scruples, and the scruple into 20 grains.
In Avoirdupois weight, the pound contains 16 ounces, but the ounce is less by near one-twelfth than the Troy ounce; this latter containing 4S0 grains, and the former only 4371. The ounce contains 16 drachms ; SO ounces Avoirdupois are only equal to 73 ounces 'Troy; and 17 pounds Troy are equal to 14 pounds Avoirdupois.
By Avoirdupois weight are weighed meat, grocery wares, base metals, wool, tallow, hemp, drugs, bread, &c.
Comparison between Troy and Avoirdupois 175 Troy pounds are equal to 144 Avoirdupois pounds. 175 Troy ounces are equal to 192 Avoirdupois ounces. 1 Troy pound contains 5760 grains.
1 Avoirdupois pound contains 7000 grains.
1 Avoirdupois ounce contains 4371 grains.
1 Avoirdupois drachm contains 27.84375 grains.
1 Troy pound contains 13 ounces, 2.651-128576 drachms Avoirdupois.
1 Avoirdupois pound contains 1 lb. 2 oz. 11 dwts. 16 gr. Troy.
Therefore the Avoirdupois lb. is to the lb. Troy as 175 to 144, and the Avoirdupois oz. is to the Troy oz. as 437,1 to 480.