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.

    77/116 (page 73)
    O;.] For, if the Storm itfelf ( as it was then generally imagin'd) was the remainingEfo fort of a Hurricane from the Coafts of Ame¬ rica ; if the Force wherewith the Cloud was impell’d, was vaftly fuperior to that of its Gravitation: From thence it will follow* that the farther any fuch Claud moves on in a direft Courfe, or very little declining from a ftraight Line, the higher mu ft fuch a Cloud rife in its perpendicularDiftance from the convex Surface of the Earth \ and the lefs Refinance it meets with from the upper Regions of the Atmofphere, the fwifter it will move. But when the protrufive Force of the Wind abates, and that of Gravitation prevails, the Cloud itfelf will acquire a Dc- gree of Velocity from its extraordinary Height, and fall down, as this was obfeiVd to do, in violent Rain, or Flail. And this will let us into the natural Reafon of a vulgar Obfervation, viz. That in cloudy and ftormy Weather, when the Windfalls, it will commonly Rain, becaufe the Clouds are carry’d on by the Strength of the Wind, in a ftraight Courfe to a greater Height, than the Denfity of the fu-* perior Regions can fupport ; as foon there¬ fore, as the Horizontal Impulfe ceafes, the Clouds, by their own natural Gravity, mult defcend in Rain. Such a moderate Height, as we have here affign’d to fuch of the Clouds as con- fi,ft of aqueous Exhalations, is accountable K for