160 



PHILOSOPHY OF STORMS. 



of the cloud above the cloudy pillar, endeavor to find out 

 its height in the same manner, and describe its form, and 

 all the phenomena attending it, as near as possible. 



129. For the sake of our correspondents who may not have 

 access to tables, we insert a table of dew points, in which the 

 column to the left is the dew point temperature, the middle 

 column the corresponding elastic force of the vapor in the 

 air in inches of mercury, and the right hand column is the 

 weight of the vapor proportional to the air containing it 

 when the mercury stands in the barometer at thirty inches, 

 the weight of the air being unity. 



Philadelphia, July 7, 1837. 



JAMES P. ESPY, Meteorologist. 



