302 



Of the Propagation of Heat 



As all the experiments were made in the same man- 

 ner, and with equal care, and differed only in respect to 

 the manner in which the outside of the jar, above the 

 surface of the ice in it, was covered, their results shew 

 the effects produced by those differences. 



I should perhaps have suspected that the greater quan- 

 tity of ice which was melted when the heat of the water 

 in the jar was confined for the longest time had been oc- 

 casioned, at least in part, by the Heat communicated 

 downwards by the medium of the glass ; but that this 

 could not have been the case was evident, not only from 



