exhibited by Hoar Frost. 



41 



Section of a bar with 



the true position of the. 



crystallization. 



The crystallization 

 magnified* 



Crystallization of Hoar Frost on an Iron Railing. 



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, being 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 tof single crys- 

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

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

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



