144 PHILOSOPHY OF STORMS. 



thrown inwards and forwards. The Brunswick spout of 

 the 19th of June, 1835, affords a well known example of 

 this, an account of which is given by A. D. Bache, President 

 of the Girard College, in the transactions of the American 

 Philosophical Society, and also by Professor W. R. Johnston, 

 in the Transactions of the Philadelphia Academy of Na- 

 tural Sciences. (See Sect. VII.) 



Another remarkable fact will not escape the observation 

 of the reader who examines with care the report of this 

 storm. The wind on the 16th, before very much rain and 

 snow had fallen, was every where feeble and irregular, and 

 especially so in the New England States ; but on the 17th, 

 when much rain and snow had already fallen, the wind be- 

 came strong, and the irregularities nearly ceased. So on the 

 western border of the storm, at Wilmington, for instance, 

 the wind was much stronger on the 17th than it had been 

 on the 16th. 



The several links of our chain of argument may now be 

 exhibited in juxtaposition. 



1. The air did blow inwards towards a region not far 

 from the southern border of the storm. 



2. The air did therefore ascend over that region. 



3. It cooled a little more than one degree of Fahrenheit 

 for every hundred yards of its ascent, as is known by ex- 

 periment. 



4. When it ascended as many hundred yards as the tem- 

 perature of the air was above the dew point, the vapor in 

 the air would begin to condense into cloud. 



5. When the vapor began to condense, its caloric of elas- 

 ticity would be given out to the air in contact with the con- 

 densing vapor. 



6. This caloric of elasticity would change the law of 

 cooling, in ordinary states of the dew point, from one de- 

 gree for a hundred yards of the ascent to one half a degree, 

 so that the air in the cloud, was one half a degree warmer 



