THEORY DEDUCED FROM PHYSICAL LAWS. 13 



rains fall heaviest on the mountains, the clouds tend to 

 them, " and it is frequently seen raining there when it is 

 perfectly dry on the plains below." Now if all these facts 

 be taken in connexion with the great fall of the barometer, 

 which the author says accompanies these storms, amount- 

 ing to one inch and eight-tenths when the wind is S. W. 

 and attended with great rain, it is certain, on dynamical 

 principles, that the wind blows towards the storm, and 

 therefore it must ascend in the region of the storm itself. 

 And as it sometimes hails, we may infer that drops of rain 

 are carried upwards at least three miles or more, to reach 

 the elevation of perpetual congelation in that low latitude. 



28. From the following hint of Shotte, in the Royal Phi- 

 losophical Transactions for 1780, it appears that tornadoes 

 on the western coast of Africa, in latitude 16 north have 

 the same direction. He says, in the rainy season, beginning 

 about the 15th of July, the wind is generally between east 

 and south, from whence the tornadoes come. As the tor- 

 nado approaches the breeze dies away, and a calm suc- 

 ceeds just before the tornado comes on. 



And in the Edinburgh Journal for 1827, it is stated con- 

 cerning squalls of wind and rain on the western shore of 

 Africa, that for some time every day, at 9 o'clock, A. M., 

 black clouds began to appear on the mountains, and gen- 

 erally reached the shore about two P. M., while all the time 

 a gentle wind at sea was blowing towards the cloud. 



It is not my purpose at present to enter into all the details 

 of the theory; but there is one point, on which the truth 

 of the theory manifestly depends, which requires a very 

 particular notice : and that is, does the wind blow towards 

 the centre of a rain in the lower part of the cloud ? The 

 following facts I trust will answer this question in a satis- 

 factory manner. 



29. On the llth, 12th, 13th and 14th of May, 1833, there 

 fell in the middle counties of the State of New York, in 



