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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    [ *9 ] T o make this ftill more evident, take a ftrong Glafs CylindricalTube, closed at the upper End, with a Sucker well fitted to the inward Cavity, well moiften'd, and prelVd up to the very Top of it; immerge this with the Air within it, into a Veffel of Water, and no Water can, or will rife up in it, becaufe the Refinance of the Air within the Tube, is equal to the Preffure of the Air without; then keeping the lower and open End ftill under the Water, draw back the Sucker by main Force, and the Moment the Air and Sucker are extracted out of the Tube, the Water will immedi¬ ately rufh in, and fhoot up with furprifing Force and Velocity to the Top of it, T o account for this, we muft have re- courfe to a known Law in Hydro ft aticks, viz. That all Fluids, under a State of Compreft fion, direct their Motion that Way, towards which there is the leaft Refiftance. Now the Tube, by the Experiment above- mention'd, having no Air within, and the Air without, lying as a Weight incumbent upon the Surface of the Water, it is evident that the Preffure of the outward Air, can only aft and exert it felf, by forcing the Water up the Tube, where there is no Pve~ fiftance, nothing to oppofe its Paffage. And this it will do, kill either the Extre¬ mity of the Tube ftops its Afcent, or kill