29° 
Sir -Benjamin Thompson’s 
Time elapfed 
9 - Heat loft. 
, 
©0 
O 
0 
M. S. 
1 55 
70 
0 12 
60 
0 3 3 
5 ° 
2 15 
40 
4 0 
3 ° 
9 55 = 
total time of cooling from 8o° to 30°. 
Time from 70° to 30° = 8^ o" ; but in the experiment N° 
12. with the thermometer N° 2. the time employed kb cooling 
from 7 o° to 30° was only 6 7 u' 7 , In this experiment, with 
the thermometer N° 3. the time employed in -cooling from 6o° 
to :o° was *]' 4 $ /y ; but in the above-mentioned experiment, with 
the thermometer N° 2. it was only 5' 20". It is true, the air of 
the room was fomewh at cooler when the former experiment 
was made than when this latter was made with the thermo- 
meter N° 3. ; but this difference of temperature, which was 
only 2°\ (in the former cafe the thermometer in the room 
{landing at 16 0 , and in the latter at iS°|) certainly could not 
have occafioned the whole of the apparent difference in the 
refults of the experiments. 
Does air receive heat more readily than it parts with it ? This 
is a queftion highly deferving of further inveftigation, and I 
ihall not fail to give it a full examination in the courfe of my 
projedted inquiries ; but leaving it for the prefent, I fhall proceed 
to give an account of the experiments which I have already 
made 
It 
* Conceiving it to be a ftep of confiderable importance towards coming at a 
further 
