376 DR. J. T. BOTTOMLEY AND MR. F. A. KING ON THERMAL 
Details of Separate Experiments. 
Group I.— Sooted Globe Cooling in Vacuum. 
I. 
II. 
September 18, 1906. 
June 28, 1906. 
Copper globe finely sooted.* 
Copper globe finely sooted. 
Vacuum pressure immeasurable on M‘Leod gauge. 
Vacuum pressure 
= 0-03 M. 
Temperature of enclosure 
= 79° ■ 
5 absolute. 
Temperature of enclosure = 79 
absolute. 
Abso- 
Abso- 
Differ- 
lute 
Differ- 
lute 
No. 
ence of 
tempe¬ 
ratures. 
Emissivity. 
tempe¬ 
rature 
of 
Emission 
No. 
ence of 
tempe¬ 
ratures. 
Emissivity. 
tempe¬ 
rature 
of 
Emission 
e. 
0 4 -0o 4 ' 
e. 
0 4 -0o 4 ' 
(t-ty c. 
globe. 
(t - ty c. 
globe. 
6. 
6. 
° c. 
o 
° c. 
0 
1 
193-1 
2-064 x 10“ 5 
272-6 
7-270 x 10- 13 
1 
194-9 
2-021 x10- 5 
273-9 
7-047 x 10" 13 
2 
189-6 
2-035 „ 
269-1 
7-414 „ 
2 
181-5 
1-922 „ 
260-5 
7-640 „ 
o 
O 
183-1 
1-976 „ 
262-6 
7-673 „ 
3 
170-6 
1-824 „ 
249-6 
8-098 „ 
4 
174-3 
1-889 „ 
253-8 
8-012 „ 
4 
165-8 
1-775 „ 
244-8 
8-284 „ 
5 
166-6 
1-802 „ 
246-1 
8-274 „ 
5 
161-2 
1-726 „ 
240-2 
8-456 „ 
6 
159-7 
1-714 „ 
239-2 
8-484 „ 
6 
153-0 
1-627 „ 
232-0 
8-710 „ 
7 
153-6 
1-626 „ 
233 • 1 
8-575 „ 
7 
149-3 
1-578 „ 
228-3 
8-799 „ 
8 
148-2 
1-539 „ 
227-7 
8-613 „ 
8 
142-4 
1-480 „ 
221-4 
8-918 „ 
9 
143-1 
1-452 „ 
222 • 6 
8-603 „ 
9 
139-4 
1-430 „ 
218-4 
8-914 „ 
10 
138-7 
1-363 „ 
218-2 
8-489 „ 
10 
136-5 
1-381 „ 
215-5 
8-901 „ 
III. 
IV. 
July 5, 1904. 
June 21, 1906. 
Copper globe sooted. 
Copper globe finely sooted. 
Vacuum pressure 
= 0-18 M. 
Vacuum pressure 
= 8-0 M.t 
Temperature of enclosure = 80° 
absolute. 
Temperature of enclosure = 80° 
absolute. 
Abso- 
Abso- 
Differ- 
lute 
Differ- 
lute 
No. 
ence of 
tempe¬ 
ratures. 
Emissivity. 
tempe¬ 
rature 
of 
Emission 
No. 
ence of 
tempe¬ 
ratures. 
Emissivity. 
tempe¬ 
rature 
of 
Emission 
e. 
6W-6> 0 4 ' 
e. 
Q^-df ' 
(t - ty c. 
globe. 
it - ty C. 
globe. 
* 
6. 
°c. 
o 
°C. 
1 
185-2 
4-217 x10~ 5 
265-2 
15-92 x 10“ 13 
1 
201-1 
4-827 x10- 5 
281-1 
2 
170-0 
3-985 „ ‘ 
250 • 0 
17-53 *„ 
2 
192-5 
4-767 „ 
272-5 
3 
164-2 
3-870 „ 
244-2 
18-08 „ 
3 
184-8 
4-707 „ 
264-8 
4 
158-7 
3-755 „ 
238-7 
18-68 „ 
4 
171-0 
4-588 „ 
251-0 
5 
154-0 
3-639 „ 
234 • 0 
18-95 „ 
5 
158-9 
4-469 „ 
238-9 
6 
145-4 
3-407 „ 
225-4 
19-50 „ 
6 
153-3 
4-409 „ 
233-3 
7 
138-2 
3-176 „ 
218-2 
19-72 „ 
7 
143-4 
4-290 „ 
223-4 
8 
132-3 
2-945 „ 
212-3 
19-57 „ 
8 
134-7 
4-170 „ 
214-7 
9 
127-3 
2-713 „ 
207-3 
19-13 „ 
9 
127-2 
4'052 ,, 
207-2 
10 
124-7 
2-598 „ 
204-7 
18-89 „ 
10 
123-7 
3-992 „ 
203-7 
* Copper globe with same coating of soot as in experiment of June 28, 1906. 
t Copper enclosure leaking slightly. 
) 
