1 28 Count Rumford’s Enquiry concerning the Nature of Heat , 
efficacious in facilitating the passage of heat into the instrument, 
I suffered both instruments to remain in the cold room all night ; 
and, entering the next morning, at half an hour past seven 
o'clock, I found the temperature of the water in the naked instru- 
ment, No. 3, to be 5o|°: that in the instrument No. 4, which 
was covered with gold-beater’s skin, was 49^° ; while the air of 
the room was at 48°. 
At 7 h 3o m A. M. I removed both instruments into a warm 
room, and observed the times of their acquiring heat to be as 
expressed in the following Table. 
Times when the obser- 
vations were made. 
At 7 h go m - 
Observed Temperature. 
No. 3, No. 4, 
naked. covered. 
5 °i° - - 4 9 i° - 
Temperature 
of the air of 
the room. 
- 64° 
7 45 
- 
- 
- 
5 H - " 
5 - 
- 
- « 4 t 
8 — 
- 
- 
- 
52 f - - 
53 i - 
- 
- 65 
8 15 
- 
- 
- 
53 i - “ 
Sii - 
- 
- — 
00 
00 
0 
- 
- 
- 
54 i - ” 
50 
“ 
- — 
8 45 
- 
- 
- 
55 l - - 
571 - 
- 
- — 
9 — 
- 
- 
- 
56 * - - 
58 * - 
- 
- — 
9 3 ° 
- 
- 
- 
57 i - ~ 
60 
- 
“ — 
10 ■ — 
- 
- 
- 
i 
H i+ 
00 
*0 
6ii - 
- 
- — 
10 30 
- 
- 
- 
59 t - - 
62-i - 
- 
- — 
11 — - 
- 
- 
- 
6o± - - 
63 
- 
- — 
11 30 
- 
- 
- 
61 - - 
6 3 i - 
- 
- 
The results 
of this experiment, and 
of several others similar 
to it, showed, in a manner which appeared to me to be perfectly 
conclusive, that those substances which part with heat with the 
greatest facility, or celerity, are those which also acquire it most 
readily, or with the greatest celerity. 
