Page:The American Cyclopædia (1879) Volume XVI.djvu/560

 540 WEIGHTS AND MEASURES of the act 5 George IV., several elements of reduction of the pendulum experiments, on which some of its provisions were based, had been found to be doubtful or erroneous, there having been defects in the agate planes of the pendulum used by Oapt. Kater, and errors in finding its specific gravity, and in reductions for buoyancy of the air and for elevation above the sea level. They concluded that the course prescribed in the act would not necessarily re- produce the original yard ; that the other defi- nition in the act of the yard as a certain brass rod was the best that could be adopted ; and that by aid of the astronomical society's scale, and a few other highly accurate copies known, the standard could be restored without sensible error. Mr. Daily was selected to prepare the new standard, having five copies of the pre- ceding on which to base his comparison ; and on his death in 1844 Mr. Sheepshanks con- tinued the necessary observations, the latter alone executing in all, in the course of this la- bor, about 200,000 micrometric measurements. Of several standard copies finally prepared by him, each being a square inch bar, of a bronze consisting of copper with a small percentage of tin and rinc, 88 in. in length, with half-inch wella sunk to the middle of the bar, one inch from each end, in which the lines defining the yard are drawn on gold plugs, six were finally selected and reported by the commissioners in March, 1854; of these, the one marked "Bronze, 19" was selected as the parliamentary stan- dard yard, the remaining five being deposited, along with copies of the standard of weight, with as many public institutions and scientific bodies. These standards were legalized in Ju- ly, 1855 ; and in case of loss of the parliamen- tary copy, it was provided that the standards should be restored by comparison of the other selected copies, or such as might be available. Thus, the latest verdict of science may be re- garded as adverse to the practicability of basing a system of weights and measures on any in- variable natural unit of dimension. Bronze bar No. 11, which has the standard length at a temperature of 61 '79, has been presented to the United States, and is the actual standard of comparison. The weights and measures used by the various colonies planted in America were from the first the same with those of England at the corresponding period. Consid- erable variations naturally grew up in the dif- ferent colonies, and the several weights and measures already in use being adopted with little or no change when these became states, the discrepancies continued to exist. By a. resolution of the senate, March 8, 1817, John Quincy Adams was commissioned to examine the subject of the weights and measures of the United States, including (it appears) the ques- tion of the desirableness of the adoption of the French system or some similar one. Mr. Adams had the standards employed in the va- rious custom houses of the country examined and carefully measured during the years 1819- '20 ; and in a table accompanying his report, published in Washington in 1821, he shows that very considerable discrepancies then existed within the limits of the several states, and often within the same state, in all the measures of weight, dimension, and capacity. He re- viewed the French system at length, and re- ported unfavorably to its adoption, chiefly on the grounds of the popular repugnance to a new system, of the subversion of uniformity that for a time would result, and the incon- venience, in his view, of a decimal system. By an act of congress, May 19, 1828, the brass troy pound procured by the American minister at London in 1827, which was a copy prepared by Capt. Kater of the English standard, was declared the standard troy pound of the mint of the United States, conformably to which its coinage should be regulated. The senate, May 29, 1880, directed a new comparison of the weights and measures in use at the different custom houses. This was intrusted to Prof. Hassler; and though much discrepancy was found, the mean corresponded closely with the English standards verified in 1776. Under Mr. Hassler's supervision, accurate copies of the received standards of weights and measures. were supplied to all the custom houses. Mean- while, by a joint resolution of congress, June 14, 1886, the secretary of the treasury was directed to cause a complete set of all the weights and measures adopted as standards to be delivered to the governor of each state in the Union for the use of the states respectively. These, as well as accurate balances for adjust- ing the weights, have been supplied, and the statutory standards of every state have been made conformable to the standards so fur- nished. It is to be observed that congress has never made any enactment in reference to the old English standards which have come down to us, since the latter were necessarily in force as the national standards unless changed by legislative enactment. The only exception is the legalization of the troy pound, used in the mint, which is identical with the correspond- ing British troy pound. The other standards of the United States are the yard of 86 inches and the avoirdupois pound of 7,000 grains, both identical with the corresponding British imperial standards; the gallon, intended to represent the old wine gallon of 281 cubic inches, but defined as containing 58,372*2 grains of distilled water at its maximum density, weighed in air of the temperature of 62 F., and barometric pressure of 80 in. ; and the bushel, containing 77'6274 pounds of water un- der the same conditions, equivalent to the old Winchester bushel of 2,150*42 cubic inches. Before the completion of the new imperial standard, the American yard was taken from a scale made for the United States by Trough- ton, which was supposed to be identical with the old standard and with the astronomical society's scale, but which had never been di- rectly compared with either. On comparison