J J ^ EKptrniieiils on the Fttfion ef Id. 



though the internal motions of the hot water above it, which was giving off its heat to th« 

 fides of the jar and to the air, were very rapid, as was diftindly perceived by means of fome 

 earthy panicles or other impurities which this water happened to contain. 



The ice was examined with a very good lens, but it was a long time before any figns of 

 its melting could be perceived. The edges of the cake remained (harp ; and the minute par- 

 ticles of dull, which by degrees w^re precipitated by the hot water as it grew colder, remained 

 motionlefs as foon as they touched the furface of the ice. 



-H the hot water had been brought from the kitchen in a tea-kettle, it was not quite boil- 

 ijig-hot when it was poured into the jar. After it had been in the jar one minute, a ther- 

 mometer was plunged into it, and its temperature found to be at 180. 



After 12 minutes had clapfcd, its temperature at the depth of one inch under the fur- 

 face was 1700. At the deptli of feven inches, or one inch above the furface of the ice, it 

 was at i69j'o ; while at only 3-4ths of an inch lower, or i-4th above the furface of the ice, 

 its temperature was 40°. 



When 20 minutes had elapfed, the heat in the water at different depths was found to be 



as follows : „ 



Degrees. 



Immediately above the furface of the ice — 40 



At the diftance of half an inch above it — 46 



At 1 Inch — 130 



At 3 Inches — '59 



At 7 Inches • — ii^o 



When 35 minutes had elapfed, the heat was as follows : 



At the furface of the ice — 4^ 



Half an Inch above it — 7^ 



I Inch above it — — — "0 



3 Inches — — — ^4^ 



5 Inches - — H8i 



7 Inches — '49 



At the end of one hour the heat was as follows : 



At the furface of the ice — 4° 



1 Inch above it ~~ °0 



2 Inches - '"^~~~ — " ^ 



3 Inches ■ " '^° 



4 Inches — 13° 



7 Inches — — — — 131 



After one hour and 15 minutes had elapfed, tlie heat was found to be as follows : 



Dcgucs. 

 At the furface of the ice — 4° 



1 Inch above it — — — 82 



2 Inches — JO^ 



3 Inches — '-3 



The heat of the water had hitherto been taken near the fide of the jar:— in the two foU 

 lovyiDg trials it was meafured in the middle or axis of the jar. 



■When 



