Atmosphere : a philosophical work / by George Woodhead.

  • Woodhead, George.
Date:
1852
Catalogue details

Licence: Public Domain Mark

Credit: Atmosphere : a philosophical work / by George Woodhead. Source: Wellcome Collection.

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    and tlie glass then be turned upside-do^vn, in such a manner that no air can enter it in the act of turning, and that the water may have full possession of the inside of meter, an instrument whicli usually consists of a glass tube six or eiglit inches long, and about the twentieth part of an inch in diameter, termi- nating in a hollow ball at the lower end, which is filled with mercury, extending into the tube, as repre- sented in the annexed drawing, and hermetically sealed, by the blowpipe, at the other end. To fill the ball with mercury and complete the instru- ment, the air must be extracted or expelled, the mercury introduced through the tube, and the end her- metically sealed. It is then fastened to a frame of metal, wood, or ivory, on which the degrees of heat are marked. The mercury in the tube rises and falls with the strength of the heat which is supposed to act upon it. The accompanying figure shows the form of a thermometer. sm xso JBt ISO J20 3m. E SOfz 60- 30 go JCl- hi I ioiJs,