Volume 2

Georgical essays / [by Alexander Hunter and others; edited by A.H.

  • Hunter, A. (Alexander), 1729-1809.
Date:
1777
Catalogue details

Licence: Public Domain Mark

Credit: Georgical essays / [by Alexander Hunter and others; edited by A.H. Source: Wellcome Collection.

    123/556 (page 113)
    [ “3' ] Of the EffeB of Winds in ajfijiing and promoting the Rife of Vapours. I take the property of winds, in aflifting the folvent power of the air, to be analogous to the effedl of agitation in other menftruumsi Their efficacy in drying up the water and moiflure in the fields, roadsj and ftreets, after heavy rains, and in damp weather^ is obvious^ and eafily accounted for. The air,’ as a menftruum^ When at reft,- can only take up and diflbive a certain quantity of water ; it becomes faturated and incapable of fufpending more; but, when agitated by winds, the faturated part is blown off from contacil with the furface of the folvend^ and a freffi quantity of unfaturated air is immediately ap¬ plied thereto. By which means the pipcefs of evaporation goes forward ‘ v/ith great celerity, and the moiflure upon the flirface of the earth, is foon dried up. In damp and low fituations,- fuch as marfhes^ bogs, and vallies furrounded by high moun¬ tains, there being no winds or agitation of the air, miffs and fogs are feen hanging like thick clouds j and in fuch places the grafs and other H veo;etables