420 



Of the Propagation of Heat 



If the agreement of these experiments with the ther- 

 mometers No. 2 and No. 3 surprised me, I was not 

 less surprised with their disagreement in the experiment 

 which follows : 



Experiment No. 16. 



Taking the thermometer No. 3 out of the boiling 

 water, I immediately suspended it in the middle of a 

 large room, where the air, which was quiet, was at the 

 temperature of 18^ R. and observed the times of cool- 

 ing as follows : 



Time e'apsed. 

 M. S. 



1 55 



O 12 



33 



2 15 



4 o 



Heat lost. 

 80 



o 

 70 



60 

 50 

 40 



30 



9 55 = total time of cooling from 80 to 30. 



