Propagation of Heat inFluids. 561 
holes was put on the furface of the i¢e to defend it while the 
hot water was pouring in, which was done through a long 
wooden tube, ftopt with a cork at the lower end, but per- 
forated with a number of {mall holes in the fides, immedi-« 
ately above the cork, to make the water iffue horizontally, 
and not impinge with force againft the bottom of the 
wooden difh, which of courfe floated as the water role} 
which tended to leffen the motions in the liquid. The difh 
was then carefully removed from the furface of the water 
of. 
The experiments were varied by fometimes leaving the 
upper part of the jar furrounded by the atmofphere, at other 
times by covering the part occupied by the hot water with 
cotton, and, at others, by keeping the jar plunged to its 
brim in melting ice and water. 
The mean quantity of ice melted by hot water in 30/, 
when the jar was kept plunged to its brim in melting ice 
and water, was 3997 grains; when furrounded by air at the 
temperature of 41°, 456 er.; when furrounded by air at the 
temperature of 61°, 558: er.; when covered up by a thick 
and warm covering of cotton, 690! gr. 
When the experiments were fimilar, the mean refults of 
thofe which were made with water at different temperatures 
were as follows : 
In the experiments in which the part of the jar occupied 
by the water was expofed uncovered to the air at the tempe- 
rature of 61°, with boiling water the quantity of ice melted 
in 30 minutes was 558+ er.; with water at the tempera- 
ture of 61°, 646 gr.; with water at the temperature of 41°, 
574 ST. 
In the experiments in which ‘the jar was wholly fur- 
rounded by pounded ice and water, and confequently was at 
32°, the quantity melted in 30! with boiling-hot water was 
3992 er.; with water at the temperature of 61°, 661 gr. 5 
with water at the temperature of 41°, 541 gr. 
From 
