exhibited by Hoar Frost. 



41 



K\\\wiHiiiiiiiiiiiiiiiiimiiiiiiiiiii iiiiiniiii»iii iiiiiiinnniininiiiHiniiiiiiiniiimiimilf 



Section of a bar, with 



the true position of the 



crystallization. 



The crystallization 

 magnified. 



The temperature was little less than the freezing point, and 

 there was a moderate fog with a high barometer, and an easterly 

 wind ; but no other meteorological phenomena were observed, nor 

 had I any opportunity of examining the state of the atmospheric 

 electricity, beirig far from home, and casually visiting in Portland- 

 place, where this sketch was made. 



Although the general effect of the distribution of this deposit 

 of ice is sufficiently visible in the drawing, it will require a few 

 words of explanation. The points did not consist of single crys- 

 tals, but of pyramidal bodies, formed of crystals so minute and 

 entangled, that their forms could not be discovered by the lens. 

 They were about the sixth of an inch in length, and distant from 



