3 8a Rev. Mr. Powell's experiments , fife. 
of the apparatus did not vary. The results of two sets of 
experiments are as follows : 
- 
Distance 6 inches. 
No. I. 
Min, 
Sec. 
3 Glasses. 
Middle Glass blackened. 
2 Glasses. 
2d blackened. 
Exp. 1, 
Exp. 2 . 
Exp. 1. 
Exp. 2 . 
O 
17.25 
17.25 
I7.25 
17.25 
17.25 
30 
17.5 
! 7-5 
* 7-5 
* 7-5 
17-5 
I 
— 
* 7-75 
17,75 
* 7-5 
17-75 
17-75 
30 
1 7-75 
17-75 
17-75 
17.75 
1775 
2 
— 
18 
17-75 
17-75 
17-75 
18 
3 ° 
18 
18 
1 7-75 
17-75 
18 
3 
18 
18 
18 
18 
18 
Distance 3 inches. No. II. 
Min. 
Sec. 
1 Glass. 
2 Glasses. 
2 Glasses. 2d blackened. 
Exp. 1. 
Exp. 2 . 
O 
15.25 
* 5-5 
16 
16 
30 
16 
16.25 
16.5 
1675 
I 
— 
16.5 
16.5 
16.75 
17 
30 
17 
1 7 
17.25 
17.25 
2 
17.25 
17.25 
1775 
17-75 
(13.) From these results, I think it will be admitted that 
no sensible difference appears in the two cases, sufficient to 
warrant any such conclusion as that alluded to. If the expe- 
riments described in this paper be regarded as sufficiently 
accurate, it follows upon the whole, that two principal excep- 
tions to the general law, that simple heat cannot radiate 
through glass, are done away. 
St. Helen’s Place, March 9, 1826. 
