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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    C S3 ] Earth, feemed rather to intimate its Failing. * * Ajmd here 1 might with Reafon, as it was once my Intention, diimifs the Reader, with this general Theory of the Barometer, without defcending to Particulars, or en¬ gaging in any farther Difquifitions about it: But fince the Spring of the Air^ has, no doubt, a real Share in producing the Effects here accounted for, it would be too mate¬ rial an Omiflion to pafs it over in Silence, without taking a juft and proper Notice of it. As the Air is an elaftlc Fluid, capable (as we above obferved) of Compreflion and Dilatation 5 fometimes yielding and bend¬ ing beneath the incumbent Preffure, and again riling and expanding itfelf in propor¬ tion to the Abatement of it: So the chief Ufe and Effedt of this elaftic Property feems to be this, viz. To preferve the Ba¬ lance of the Atmofphere; and by its occa- fional Contraction and Expanfion, to ac¬ commodate itfelf to the different Degrees of Preffure in the feveral Parts of it ; and thereby, as well to keep the Air itfelf, as the Clouds and Vapours floating in it, as near as may be to an /Equilibrium. T o this elaftic Force of the Air, fome Authors (too precipitate in their Conclu- fions) have entirely afcribed the Rife and Fall of the Mercury in the Barometer; but it is very certain, without any juft Premifes, Ql'