22 PHILOSOPHY OF STORMS. 



no theory of hail can stand, which does not show how drops 

 of water are first formed and afterwards frozen. 



46. Again : nothing can be more satisfactory than the 

 explanation which the theory affords of the immense quan- 

 tity of rain and hail which sometimes falls, in a very short 

 time on a very small extent of land. Nothing is wanted 

 for this purpose, but the stoppage, for a short time, of the 

 horizontal motion of the spout. 



47. This may be effected by a mountain or island of the 

 proper height. If it is very high, as the Himalayas, the rain 

 and snow will be all on the windward side ; if it is barely 

 sufficient to cause a condensation of vapor when the air 

 blowing over it comes to the top, the spout will be so formed 

 as to discharge its water on the leeward side, for as it as- 

 cends above the point of condensation, it will be pressed over 

 to the leeward side by the prevailing current of air. 



48. On the 26th of July, 1819, the mouth of the Catskill, 

 eight miles east of the Catskill mountains, previous to the 

 storm, the air was thick and sultry, clouds low, and wind 

 south west. About five P. M. two very dense black clouds 

 were seen to rise up, very rapidly to the zenith, one in the 

 north east, the other in the south west, and at the same time 

 two sloops in the North River were seen approaching each 

 other under a full press of sail. Immediately on the meet- 

 ing of the clouds there commenced a violent rain which did 

 not abate for one hour and did not entirely cease for three 

 hours and a half. During this period there fell at least 

 fifteen inches of rain over a space of about nine miles in di- 

 ameter, bordering on the Catskill. 



This account is given, with a great many other particu- 

 lars, by Benjamin W. Dwight, in the fourth volume of Silli- 

 man's Journal ; but the direction of the wind, in the borders 

 of the shower, is not given. 



49. In the Ann. de Chem. et de Phys. for February, 1835, 

 M. S. Berthelot gives a very particular account of a storm 



