An historical and philosophical account of the barometer, or, weather-glass, wherein the reason and use of that instrument, the theory of the atmosphere, the causes of its different gravitation are assigned and explained. And a modest attempt from thence made towards a rational account and probable judgment of the weather / By Edward Saul, A.M.

  • Saul, Edward, 1677-1754
Date:
1766
Catalogue details

Licence: Public Domain Mark

Credit: An historical and philosophical account of the barometer, or, weather-glass, wherein the reason and use of that instrument, the theory of the atmosphere, the causes of its different gravitation are assigned and explained. And a modest attempt from thence made towards a rational account and probable judgment of the weather / By Edward Saul, A.M. Source: Wellcome Collection.

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    [ *7 ] tiie Tube, he brought the Barometer into more general Ufe and Service j either as a certain Meafure of the Weight of the Air, or as a variable Indication of the Changes of the Weather. Flow, and why it is fo, will appear from the ConArudtion of the Weather-glafs, which in the common Form, is made after the following Manner Take a Glafs Tube of about 35, or 36 Inches long, and near half, or the third Part of an Inch in the Diameter ; clofed or her¬ metically fealed at one End, and open at the other. Fill it up with Mercury, or Quickfilver, well cleared and purified $ then, flopping the Orifice clofe with your Finger, invert the Tube, and plunge it to¬ gether with' your Finger into a Bafon of Quickfilver, and when it is fixed or fuf- pended in a perpendicular Pofture, with the Orifice of the Tube below the Surface of the Mercury, at a little diftance from the Bottom of the Bafon, withdraw your Finger from the Orifice of the Tube. It is found by Experience, that only fuch a Part of the Quickfilver within the Tube, will fubfide and run out into the Ba¬ fon, as exceeds the Weight of a proportional Column of Airy and that the remaining, and far greater Part of the Quickfilver will continue fupported within the Tube, ex¬ actly at fuch an Height, as comes to an /Equilibrium with it. C From