METEORIC RIVERS OR WATERFALLS. 423 



be true, it is natural and proper for us to inquire how these 

 .things can be. 



By what power, hitherto unknown, is this mighty mass 

 of water suspended until it accumulates so as to become 

 " a river from the clouds " ? 



The answer to this sublime question may be stated in a 

 few words. 



The wind, which blew inwards, as it did with great vio- 

 lence, on coming to the side of a mountain 'or hill, must 

 necessarily ascend ; in ascending it would carry up drops 

 of rain to a height proportionate to its velocity ; when these 

 drops became so numerous and heavy that they could no 

 longer be forced upwards, which they would soon do, by 

 the constant accession which would be made to them by 

 the condensing vapor in its ascent, whether the sheet of 

 water thus formed in the air were thick or thin, on begin- 

 ning to descend, it would naturally break up into parts, 

 and in descending each part would naturally form itself 

 into the shape of an inverted cone, or rather trumpet, with 

 the little end downwards. The latent caloric evolved by 

 the condensing vapor, it is now known, is sufficient to ex- 

 pand the air in the region of the cloud between six and 

 seven thousand cubic feet for every cubic foot of water that 

 is generated by the condensing vapor, after making due al- 

 lowance for that condensation, and thus furnishes an ade- 

 quate upmoving power. 



It would be vain to speculate on the height to which 

 these masses of water are carried up. Perhaps the distance 

 at which the meteoric rivers fall apart, and other phe- 

 nomena attending their fall, may yet furnish data sufficient 

 to bring the calculation within the power of mathematics. 



It would appear from the following fact, that a river of 

 hail sometimes falls from the clouds; and of course it must 

 fall from a great height, even above the region of perpetual 

 congelation. 



