. 
Propagation of Heat in Fluids. 359 
fame jar, by means of two flender laths, a trifle longer than 
the diameter of the jar, forced down into it, and laid acrofs 
each other over the ice. Cold water to cover the ice tothe 
height of + of an inch was then poured into the jar to pre- 
vent its breaking by the fudden application of boiling water 
with which it was next filled. To protect the ice while the 
. hot water was pouring in, a circular piece of paper was pre- 
vioufly laid on ics furface, which was afterwards gently re- 
moved by means of a ftring faftened to one fide of it. The 
refult of the experiment proved, that the Count was not 
miftaken in his ideas. When 20’ had elapfed, the heat in 
_the water at different depths was found to be—immediately 
above the furface of the ice 40°; at + inch above it 46°; at1 
inch 130°; at 3 inches159°; at7 inches 160° ; at the end of 
35/ it was, at the furface of the ice 40°; at Zinch 76°; at 1 
inch 110°; at 2 inches 144°; at 3 —.148°; at5—148$°; at 
7— 149°. After an hour and 15° it was at the ice 40°; 
Z inch above it 82°; 2 inches 106°; 3 —123°.—Thefe 
were taken near the fide of the jar, the following at the axis; 
at the end of rh. 30m. at the furface of the ice 40°; at x 
jnch above it $4°; at 2 inches 115°; at 3— 116°; at 7 
— 117°. At the end of 2 hours ftill 40° at the furface of 
the ice; 76° at 1 inch above it; 94° at 2 inches; 106° at 
35 108 at 4; 108-° at 6; 108; at 7 inches.—An end was 
now put to the experiment, the water was poured off; and 
the remaining ice being weighed, it was found that 5 oz. 6 or. 
Troy had been melted, Taking the mean temperature of 
the water at the end of the experiment at 106°, it appeared 
that 73: 0z. of hot water employed was cooled 78°. As 1 oz. 
of ice abforbs juft as much heat in being melted as 1 oz. of 
water lofes in being cooled 140°, each of thefe 73" oz. would 
give off as much heat as would melt 7,8. ths of 1 oz. of ice; 
that is, all of them together as much as would melt 40,5, 
ounces of ice; bat the quantity melted was only about 5 oz. 
ad hence it appears that /e/s than th part of the heat loft 
by the water was communicated to the air. -Or, ice mitts 
Aa4 py 
