. Appendix to Captain Parry's journal of a second voyage [microform] : for the discovery of a north-west passage from the Atlantic to the Pacific, performed in His Majesty's ships Fury and Hecla in the years 1821-22-23. Science; Botany; Sciences; Botanique. 253 ON THE CONTRACTION OF MERCURY. These experiments were made with the same glass vessel with which those upon the expansion of air were made, which being nearly filled with mercury, became a thermometer upon a large scale, but open at the end of the stem. The relative cap'>ciiie8of the whole vessel, and the several parts of the stem, w
. Appendix to Captain Parry's journal of a second voyage [microform] : for the discovery of a north-west passage from the Atlantic to the Pacific, performed in His Majesty's ships Fury and Hecla in the years 1821-22-23. Science; Botany; Sciences; Botanique. 253 ON THE CONTRACTION OF MERCURY. These experiments were made with the same glass vessel with which those upon the expansion of air were made, which being nearly filled with mercury, became a thermometer upon a large scale, but open at the end of the stem. The relative cap'>ciiie8of the whole vessel, and the several parts of the stem, were determined by many trials, by weighing the contained portions of mercury with a delicate hydrostatic balance (made by Newman, of Lisle- street), in very small scales, or cups, of platinum. The mercury experi- mented upon, had been distilled for the purpose of chemical experiments; and by a mean of five different trials with the same instrument, its specific gravity in distilled water of the temperature of + 58° Fahrenheit, was The experiments were confined to temperatures not lower than —30' Fahren- heit, as there is some uncertainty arising from a suddenness in the contrac- tion of the mercury near its freezing point. If, upon exposing the vessel filled with mercury to these temperatures, and after a considerable time, when it appears to have reached its lowest point in the gradu'^:ted stem, the vessel be then touched, the mercury immediately descends, and this not from any change in the curvature of its upper surface only, since it is seen to descend in every part of the stem. The same circumstance was constantly observed in the common mercui^al thermometers; the same thermometer seldom indicating the same temperature A'hen its contained mercury was frozen, which was generally from — 30° to — 38° when frozen in an horizontal position. If it is frozen at lower temperatures, as at 45° Fahrenheit, it still indicates about the same temperature, viz., 30° to
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Keywords: ., bookcentury1800, booksubjectbotany, booksubjectscience, bookyear1
