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

  • Saul, Edward, 1677-1754
Date:
1735
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, and the causes of its different gravitation, are assign'd and explain'd. And a modest attempt from thence made towards a rational account and probable judgment of the weather / By Edward Saul. Source: Wellcome Collection.

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    [•7] the Tube, he brought the Barometer into more general Ufe and Service; either as a certain Meafure of the Weight of the Air, or as a variable Indication of the Changes of the Weather. H o w, and why it isfo, will appear from theConftrudlion of the Weather-glafs, which in the common Form, is made after the fol¬ lowing Manner. Takes Glals Tube of about 35, or 3 6 Inches long, and near half, or the third Part of an Inch in the Diameter ; clos’d or her¬ metically leai’d at one End, and open at the other, hill it up with Mercury, or Quick-Silver, well clear’d and purify’d ; then, flopping the Orifice clofe with your Finger, invert the Tube, and plunge it to¬ gether with your Finger into a Bafon of Quick-Silver, and when it is fix ’d or fiif- 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. I t is found by Experience, that only fuch a Part of the Quick-Silver within the Tube, will fubfide and run out into the Ba¬ fon, as exceeds the Weight of a proportio¬ nal Column of Air, and that the remaining, and far greater Part of the Quick-Silver will continue lupported within the Tube, exact¬ ly at fuch an Height, as comes to an M&quilibrium with it. C From