10 



Remarks on Indian Summers. 



winds in November are some point west of south and north, or per- 

 haps west and north of west during Indian summer. We have be- 

 fore us the meteorological register for the years 1822, 1823, 1824, 

 and 1825, from observations made by the surgeons of the army at 

 the military posts of the United States, prepared under the direc- 

 tion of Joseph Lovell, M. D., Surgeon General, U. S. army, from 

 which we here give the following extract. 



From the above table it appears, that the winds bearing north and 

 west, prevail over the south, and we believe that west and north 

 west winds would be found to prevail over all others during Indian 

 summer. 



We agree with the writer, " that electrical causes are negatively 

 concerned in the production of Indian summer," or rather that they 

 are positively concerned. For during the summer months the earth, 

 probably from its dryness, often becomes the negative, and the at- 

 mosphere, being loaded with moisture, the positive conductor of 

 electricity. Hence the frequent occurrence of thunder gusts.* The 

 vapor collecting, forms clouds highly charged with electricity, which 

 give it out to the earth. 



After the autumnal rains have completely wet the surface of the 

 earth, things are reversed. The earth now becomes the positive, 

 and tlifi atmosphere the negative conductor of electricity, and thun- 



* Thunder gusts are much more frequent, and more severe on the extensive 

 prairies of the west, than in the Atlantic stales. 



