rOE DETEEMIMNa THE EADIATING- POWEES OE SIJEEACES IN AIE. 
396 
I. Disc of Glass. 
Time, or duration of each experiment =500 beats. 
Height of barometer =30 ’5 inches. 
= -77 metre. 
Number of 
the experiment. 
Temperature of the 
radiating surface. 
Eeadings of the 
calorimeter. 
Difference of the 
readings =E^ — Ej. 
Temperature 
of the air. 
( 1 ) 
|ti=i56-o I 
4Ri=60-72 4 
4R2=62-24/ 
i-52 
64 
(2) 
4 X 2 = 1 39-8 / 
4Ri=6l-394 
4R2=63-00/ 
1-61 
(3) 
/Tj = 150-0 4 
(T2=149-5/ 
fRi=59-9l4 
4R2=61-5o/ 
1-59 
(4) 
rTi=149-2 4 
4 X 2 = 147-0 1 
4 Ri=6l-25 4 
4r2=62-77/ 
1-52 
(5) 
4 X 1 = 147-04 
4 X 2 = 147 - 5 / 
4Ri = 6l-704 
4R2=63 -i6/ 
1-56 
(6) 
rTi=147-5l 
4 X 2 = 147-5 f 
4Ri = 62-00 4 
4 R2=63-45/ 
1-45 
64 
(7) 
4 X 1 = 147-74 
4 X 2 = 147 - 7 / 
4Ri = 6l-844 
4R2=63-274 
1-43 
(8) 
4 X 1 = 148-64 
4 X 2 = 148 - 8 / 
4 Ri = 61-95 4 
4R2=63-46/ 
1-51 
(9) 
4 X 1 = 149-64 
4 X 2 = 149 - 6 / 
4Ri = 62-89 4 
4r2=64-40/ 
1-51 
Hence we obtain the following mean values : — 
(T)=148°*20 (F.), 
(R)= 62°-27; 
(T)-(R)= 85°-93. 
When (K) is expressed in Centigrade degrees, its numerical value becomes that of 6 in 
our general formula; and the value of (T) — (E,) in the same degrees, is that of t in the 
formula. Hence for the mean of the above nine experiments, 
^=16°-80, 
7=47°-74. 
Also, taking the mean of the tabulated values, 
R2-Ri=1-52. 
3 G 2 
