RADIATION IN ABSOLUTE MEASURE. 
G13 
April 2, 1890. Observed—J. T, Bottomley, A, Tanakadate. Sooted globe 
in vacuum ; thin coating. 
1 
: Time. 
1 
Deflecfciou. 
Temperatiire 
of bath. 
j 
Vacuum, &c. 
h. m. 
C 
i 3 37 p.M. 
1171-9 
16-0 
Good A^acuum.* 
16-2 
40 
1034-5 
15-7 
[ 
Vacuum impi'oviug. 
4.5 
! 
50 
864-6 
756-3 
1 . 5-9 
/Volume 10' 
/ Pressure 13 
f Volume 10 
[ Pressure 12_, 
Readings of volume and 
> pressure on the Alac- 
Leod gangc. 
55 
669-9 
4 00 
597-0 
15-9 
1 5 
535-9 
10 
483-1 
/ Volume 10. 
fPressui’e 12. 
15 
436-7 
15-9 
■ 
. 
20 
.399-0 
' 25 
365-2 
30 
. 335-4 
/ Volume 10, 
t Pressui’c 12. 
i 
' 35 
309-4 
15-6 
' 
15-9 
' 40 
286-5 
15-9 
45 
266-5 
e • 
/ Volume 10. 
t Pressure 12. 
1 50 
, 
248-4 
1 
! 
55 
i 
; 
5 00 
218-9 1 
15-9 
* Neglect first two readings, vacunm not good enough. 
It will be seen that the galvanometer readings are noted opposite particular 
instants of time. The galvanometer readings, properly corrected, give the temperature 
of the globe at those instants of time. The differences of the logarithms of these 
readings give the cooling; and the differences between the time readings give the 
intervals of time corresponding to the cooling; while also the readings themselves 
give the differences, at the beginning and end of the time intervals, between the 
temperatures of the globe and its surroundings, and also some mean between the 
pairs of readings gives the actual temperature corresponding to the emissivity to be 
calculated. The object of the subsequent calculation was to tind the absolute 
