68 THEORY of R A I N. 



IF thefe two proportions be true, the theory, fo far as de- 

 pends upon this principle of condenfation, will be confirmed. 

 It is, therefore, now propofed to give an example in each of 

 thofe propofitions, from the comparifon of which examples with 

 the obfervations made in other places, we may arrive at the 

 truth, and find the propofitions proved. 



THE firft of thefe is with regard to the greatefl quantity of 

 rain. Nobody will doubt of the Eaft Indies being a place pro- 

 perly correfponding to the terms of the proportion ; and it has 

 been found, that 104 inches of rain have there fallen in one 

 place in a feafon ; which is at leaft three times the quantity 

 which generally falls in the regions fubjecl to our obfervations. 



WITH regard to the fecond cafe, I know of no meteorologi- 

 cal regifter to confult, by which the comparative drynefs of the 

 region, fpecified in the propofition, might be determined ; but 

 there are fome notorious facts from which this conclufion may 

 be formed, by taking a proper compafs in our reafoning. 



THE Cafpian fea, fo far as it remains ftationary, in neither 

 increafing nor diminifhing, affords a meafure of the evaporation 

 from the furface of that fea, in relation to the rain that falls up- 

 on the country, which is drained by the rivers running into it ; 

 converfely, it affords a meafure of the quantity of that rain, 

 in relation to this evaporation. But this country is in the very 

 place which we would obferve, with refpecl: to the quantity of 

 rain, as being near the centre of the greatefl continent. If, 

 therefore, we could find a fimilar example in a different fitua- 

 tioii of the globe, we fhould then, in making a comparifon, 

 find data for drawing fome conclufion concerning the quanti- 

 ties of rain which fall upon thofe different places. The lakes 

 in North America will afford this comparifon. The medium 

 latitude of thefe lakes is about 45 . ; and this is nearly that of 

 the Cafpian fea ; consequently, cteteris paribus^ there fhould be, 

 in thofe inftances, an equal evaporation from equal furfaces. 



WE 



