378 
DR. J. T. BOTTOMLEY AND MR. F. A. KING ON THERMAL 
Group II.—Silvered Globe Cooling in Vacuum. 
VII. 
March 23, 1906. 
Silvered globe highly polished. 
Vacuum pressure = O'05 M. 
Temperature of enclosure = 81° absolute. 
VIII. 
April 2, 1906. 
Silvered globe highly polished. 
Vacuum pressure = 0-06 M. 
Temperature of enclosure = 79° absolute. 
Difference 
Absolute 
Difference 
Absolute 
No 
of tern- 
Emissivity. 
temperature 
No 
of tem- 
Emissivity. 
temperature 
peratures. 
e. 
of globe. 
peratures. 
e. 
of globe. 
(t - ty C. 
e. 
' 
(t - ty c. 
- 
6. 
c C. 
° c. 
1 
207-3 
5-812 x10-° 
288-3 
1 
212-0 
6-210 x 10~ t! 
291-0 
2 
197-3 
5-581 ,, 
278-3 
2 
201-4 
5-972 „ 
280-4 
3 
188-4 
5•349 „ 
269-4 
3 
191-8 
5-734 „ 
270-8 
4 
181-0 
5-118 „ 
262-0 
4 
183-5 
5-497 „ 
262-5 
5 
174-7 
4-887 „ 
255 • 7 
5 
176-5 
5-259 „ 
255-5 
6 
169-1 
4-655 ,, 
250-1 
6 
170-5 
5-021 „ 
249 • 5 
7 
164-4 
4-424 „ 
245-4 
7 
165-5 
4-783 „ 
244-5 
8 
160-1 
4-191 „ 
241-1 
8 
161-0 
4-545 „ 
240-0 
9 
156-2 
3-960 „ 
237 • 2 
9 
156-9 
4-308 „ 
235-9 
10 
150-3 
3 • 565 /, 
231-3 
10 
152-3 
3-991 „ 
231-3 
Globe has not been polished since July 20, 1905. 
In the meantime it has been hanging 
within the 
enclosure, which was exhausted. 
IX. 
X. 
July 20, 1905. 
July 11, 1905. 
Silvered globe very highly polished. 
Silvered globe tarnished surface. 
Vacuum 
pressure = 0 • 1 M . 
Vacuum pressure = 20 M. 
Temperature of enclosure = 79° absolute. 
. ..... 
Temperature of enclosure = 79° absolute. 
Difference 
Absolute 
Difference 
Absolute 
No 
of tem- 
Emissivity. 
temperature 
No 
of tem- 
Emissivity. 
temperature 
i 
peratures. 
e. 
of globe. 
peratures. 
e. 
of globe. 
(/ - ty C. 
e. 
(t - ty c. 
6. 
0 C. 
°c. 
1 
211-0 
4-027 x 10 -0 
290-0 
1 
215-0 
5-178 x10- 6 
294°-0 
9 
aJ 
207-5 
3-990 „ 
286-3 
2 
175-3 
5-022 „ 
254-3 
3 
203-7 
3-953 „ 
282-7 
3 
151-3 
4-867 „ 
230-3 
4 
200-4 
3-917 „ 
279-4 
4 
139-6 
4-764 „ 
218-6 
5 
197-0 
3-879 „ 
276-0 
5 
134-6 
4-713 „ 
213-6 
6 
193-8 
3-842 „ 
272-8 
6 
121-3 
4-557 ,, 
200-3 
7 
190-7 
3-805 „ 
269-7 
7 
110-5 
4-402 „ 
189-5 
8 
187-8 
3-768 „ 
266-8 
8 
101-4 
4-247 „ 
180-4 
9 
184-2 
3-719 „ 
263-2 
9 
93-5 
4-092 „ 
172-5 
10 
181-0 
1 3-670 „ 
260-0 
--.J 
10 
76-0 
3-679 „ 
155-0 
Globe repolished before this experiment. 
) 
