278 Of the Pi'opagatiofi of Heat 



in a tea-kettle, it was not quite boiling hot when it 

 was poured into the jar. Kh^x it had been in the jar 

 one minute I plunged a thermometer into it, and found 

 its temperature to be at 180°. 



After 12 minutes had elapsed, its temperature at the 

 depth of one inch under the surface was 170°. At the 

 depth of seven inches, or one inch above the surface of 

 the ice, it was at i692V> while at only -| of an inch lower, 

 or \ above the surface of the ice, its temperature was 



o 



40. 



When 20 minutes had elapsed, the Heat in the water 

 at different depths was found to be as follows : — 



Immediately above the surface of the ice . . 40° 



At the distance of ^- an inch above it . . .46 



At I inch ........ 130 



At 3 inches ........ 159 



At 7 inches ....... 160 



When 2S i"ninutes had elapsed, the Heat was as fol- 

 lows : — 



At the surface of the ice 40° 



1 an inch above it . . . . . . -76 



1 inch above it . . . . . . • no 



2 inches ........ i44 



3 inches ........ 14S 



5 inches ........ 1482' 



7 inches . . • . . . • • i49 



At the end of one hour the Heat was as follows : — 



At the surface of the ice ..... 4° 



1 inch above it ..o .... 80 



2 inches . . . . . . . • nS 



3 inches ........ 12S 



4 inches ........ 130 



7 inches ..... •• 13^ 



