A DESCRIPTION 



OF A 



NEW ANEMOMETER, 



By RICHARD KIRWAN, Esa. L. L. D. P. R. I. A. F. R. S. &c. &c. 



JL HAT rain, on wliose presence or absence at the different 

 seasons of the year, vegetation, and the success of agricul- 

 ture, in great measure depend, and also the temperature of 

 the atmosphere, to whose influence both animals and vege- 

 tables are subject, arise from, or at least are strictly con- 

 nected with the various directions and velocities of winds, is 

 well known. Nor has it escaped observation, that the pri- 

 mary cause of the direction of the ^v^ind from a given quarter, - 

 as well as of the velocity of its progress, is the rarefaction of 

 the atmosphere in that tract towards which it blows. The 

 reason why air does not rush in from all sides towards the 

 rarefied tracts, seems to me to be the inequality of its den- 

 sity in the surrounding tracts; for from that quarter, in 

 which the mercury in the barometer stands' highest, the air 



must 



