The construction and use of a thermometer for showing the extremes of temperature in the atmosphere, during the observer's absence. Together with experiments on the variations of local heat and other meteorological observations / By James Six.

  • Six, James, 1731-1793.
Date:
1794
Catalogue details

Licence: Public Domain Mark

Credit: The construction and use of a thermometer for showing the extremes of temperature in the atmosphere, during the observer's absence. Together with experiments on the variations of local heat and other meteorological observations / By James Six. Source: Wellcome Collection.

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    [ ]. scntially necessary: for by these means the column of mercury from d. to g. like an inverted syphon, has its two ends or surfaces turned upwards, on which the indexes alternately ascend. The cur- vature from e. to /. is also necessary for the co- lumn of mercury on each side to rest upon, and to prevent it from shifting its place in the spirits, which without it would certainly happen. For if too jjreat a deoree of heat should cause all the mercury on the side c. d. e. entirely to pass through the curvature e.f. into the sideA. the whole column then in a vertical position, without any other support than the spirit, would gradually sink down to the curvature; and the spirit passing between the mercury and the glass, would rise above it: but as long as the mercury remains in the curvature e.f. though all the rest of the column should be on one side, and even remain so for a considerable time, the mercurv ’VN'Oukl, nevertheless, retain its place in the spirit. I That part of the spirit in the small tube from g. to h. has no effect on the motion of the mercu- ry ; and is placed there lOnly to diminish the fric- tion of the index spring, immersed in it, and render it more equal to that on the other side : X. but care should be taken to leave a sufficient (piantiiy of ajr at the end i. for whenever the spi- rit