« ПретходнаНастави »
With a view to ascertain the existing varieties of fact in the weights and measures used at the several custom houses of the United States, and thereby the state of the standards in the several states, the following circular letter was, at the request of the Secretary of State, addressed, by the Register of the Treasury, to the collectors of the customs throughout the Union :
Register's Office, November 15, 1819. SIR: I am requested by the Secretary of State to ask the favor of your early information to that department, relative to the standard of weights and measures, used at the custom house in the collection of the duties of the United States; and to observe, that it will be particularly acceptable to be informed, whether, in dry measure, any other than the Winchester bushel and its parts, is used ; and the ca. pacity thereof, that is, its diameter at the top and bottom, and its depth in inches, and tenths of inches. In liquid measure, whether wine or beer measures are respectively used for wines and beer, or, whether confined to wine measure, both for beer and wine. In respect to weights—whether the troy weight is at all used, and whether Dearborn's patent balance is altogether adhered to, in collecting the duties on articles paying duty by the pound or hundred weight.
I am, &c. P. S. Be so good as to state the number of grains by your troy weight, which your avoirdupois pound weighs.
The following table is the result of the answers received from the collectors. As the cubic foot, or 1728 cubical inches of spring water, at the temperature of 56 degrees of the thermometer, weighs 1,000 ounces avoirdupois, the Winchester bushel of 2150.42 inches contains 77 Ib. 12 oz. 7 drams of the same water, and the half bushel 38 lb. 14 oz. 34 drams. The returns will shew how nearly the actual weights and measures correspond with those proportions. It win not be expected that experiments made at the custom house with scales adapted to heavy weights, in constant use, and with such water as was nearest at hand, should be marked with philosophical precision, or very minute accuracy. But it is evident they were generally made with great care, and, in several instances, repeated with various kinds of water. From the experiments of sir George Shuckburg Evelyn, it appears that the specific gravity of distilled water, at the temperature of 62, is 2522 grains troy to a cubical inch; and of that water the bushel should contain 77 lb. 9 oz. 1° drams, and the half bushel 38 lb. 12 oz. 88 drams. Mr. Pollock found the specific gravity of the pump water at Boston to be 253.6042 grains troy to the cubic inch, and of that water the statute Winchester bushel should contain 77 lb. 14 oz. 81 drams, and the half bushel 38 lb. 15 oz. 44 drams. From 38 lb. 12 oz. to 39 lb. may be, therefore, considered as the range within which the different kinds of fresh water should fill the correct standard copper or brass half bushel.
In several of the returns it is apparent that the weight certified includes that of the wooden vessel which held the water. By the experiment of the late venerable William Ellery, collector at Newport, it appears that of two half bushels of the same dimensions, one of copper and the other of wood, the former contained 1ounces more than the latter, and both of them half an ounce more of spring than of rain water : and by experiments of G. Davis, inspector at New Orleans, from whom a very interesting report was received, it appears, that, by weighing the wooden half bushel before it had been filled, and after it was emptied of Mississippi river water, there was a difference of nearly 15 ounces, to be accounted for partly by the absorption of the water into the wood, and partly by the adhesion of it to the sides and bottom of the vessel.
By the testimony of Mr. John Warner, a brass founder in London, much employed in making for country corporations brass standard weights and measures, duplicates of those in the exchequer, given before the committee of the house of commons in the year 1814, it was shewn that from the extreme difficulty and expense of turning a bushel measure truly cylindrical, the practice of the trade is, notwithstanding the act of parliament, to pay no attention to the dimensions of the measures which they make, but to rely entirely upon the trials by the weight of water which they contain. From all the admea. surements wbich have been made of the English standards, it is apparent that neither the weight of water which a bushel or half bushel may be found to hold, nor the direct measurement by the depth and diameters of the vessel, can be relied upon by itself to ascertain its exact capacity; and even when one of these tests is applied as a check upon the other, the result may differ to the extent of four or five inches upon a half bushel. The curn gallons at the exchequer, which in 1688 were found by a skilful artist to be of 272 cubic inches, in 1758 were, when remeasured by order of the committee of the house of commons, returned as of 271 or less, and one of them tried in April, 1819, by sir George Clerk and Dr. Wollaston, appeared by the weight of water which it held, to be only of 270.4 inches.
If this apparent diminution should be attributed to the decay of the vessel in the lapse of time, that will not account for the opposite re. sult of the two experiments upon the bushel, which, by direct measurement in 1758, was found to be of 2124 cubical inches, and in 1819, by the weight of water it contained, was of 2128.9 inches. The statute Winchester bushel is a cylinder 184 inches in diameter and eight inches deep: a difference of do of an inch either in the depth or diameter increases or diminishes the contents of the vessel nearly three cubical inches. Mathematical instruments are now constructed by which the division of so iso part of an inch may be discerned ; but such refinement of art cannot be applied to the making of vessels of the size of a bushel, or its half. In all such vessels inequalities in the depth, diameter, or circumference, are unavoidable, producing differences in their capacity of more than five cubical inches ; the test, therefore, by the weight of water they will hold, is more effectual for accuracy than that of measurement; its results, however, depend upon the correctness of the scales and weights as well as upon the care and attention with which the experiment is made.
As the patent scales of Dearborn are used in most of the custom houses throughout the Union, few of them possess the avoirdupois heavy weights. The correctness and convenience of the patent scales are generally attested by the collectors, who have them in use, and may be relied upon with all the confidence of which any steelyard can be susceptible.
The beer measure and the troy weight are seldom used except in the principal and most populous ports. Of forty single avoirdupois pounds the average weight in troy grains was 6998. In all the principal ports they were exact, within one grain, with the exception of New York, where the custom house pound was five or six grains. over weight: but where that of the city was exact.
ghts useStates. .
DR HALF BUSE
NO WEIGHT OF W
ditto Winchester intended. *This must include the
weight of the half bushel measure. Scales and weights at Wells. Standard from
the town of Arundel. Winchester. Winchester. The standards are kept at East;