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thermometer, 252.72 such grains *; and consequentlya cubic foot of distilled water, under similar circum-stances, will weigh 62,386 pounds avoirdupois.

That the measures of capacity may be all broughtback to an equality, and at the same time made tobear a simple relation to the standard of weight, bytaking the pint for a basis, which contains 20 ounces ofdistilled water avoirdupois, at the temperature of 62°,as nearly as it is possible to ascertain by experiment,on a vessel of that construction and workmanship.

If, then, the pint be considered as equal in bulk to20 ounces of distilled water, at the temperature of 62°,the cubic inch weighing 252.456 grains in air, atthe mean height of the barometer, the imperial gallonwill contain 277-276 cubic inches, weighing exactlyten pounds.

The following computations and proportions arecontained in the Appendix .

The pendulum t vibrating seconds of mean solartime at London , in a vacuum, and reduced to the levelof the sea, 39.1393 inches, consequently the descentof a heavy body from rest in one second of time, in avacuum, will be 193.145 inches. The logarithm2.2858828.

A platina metre at the temperature of 32°, sup-

* Or 252.456 in air, under the common circumstances of theatmosphere, when weights of brass are employed. In a vacuumat the maximum of density, that is, at 39°, the weight of a truecubic inch will be 253 grains, and of a cubic decimetre 15440. Itappears, however, from an official report, obligingly communicatedto us by Dr. Kelly, that the actual standard chiliogramme hasbeen found to contain only 15433 English grains. The proposedimperial gallon of ten pounds, or 70000 grains of water, will containvery nearly 277.3 cubic inches, under common circumstances.

-j- See Phil. Trans. 1818, page 33. and Recueil D’ObservationsGeodesiques. Par Biot et Arago. Paris , 1821. page 587.

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