228 CAPTAIN SABINE ON THE REDUCTION TO A VACUUM 
then pumped out till the gauge indicated 1.4 inch. A fresh supply of gas was 
then introduced, passing through the cylinder containing fresh muriate of 
lime, till the pressure withinside the apparatus exceeded by about 0.2 inch the 
pressure of the atmosphere on the exterior. An equilibrium of pressure was 
then produced, by permitting the escape of the small portion of gas necessary 
for that purpose. The mercury in the included barometer stood at 29.95, 
corresponding to the indication of the standard barometer of 30.24 inches at 
32°. The following observations were then made. 
Observers. 
No. of 
Coincid. 
Thermometers. 
In- 
cluded 
Barom. 
Times of 
Arc registered 
and true Arc. 
Mean 
Interval. 
Correc- 
tion for 
Arc. 
Reduc- 
tion to 
360. 
Corrected I 
Vibrations | 
at 360. 1 
i 
4 
Disapp. 
Re-app. 
Coincidence. 
Captain 
Sabine. 
Mr. 
Taylor/ 
r 
1 
2 
3 
35 
36 
37 
o 
40.0 
39.6 
O 
40.0 
39.7 
inch. 
29.95 
29.90 
m s 
22 29 
30 50 
39 13 
8 35 
17 03 
25 25 
m s 
22 39 
31 03 
39 25 
8 50 
17 15 
25 38 
1 h ms 
> 8 30 56.5 
1 
j> 13 17 07.67 
Div. 0 
0.96= 1.15 
0.44 = 0.53 
l . 
>505.03 
s 
+1.11 
+ 1.60 
86313.93 
39.8 
29 925 ; Index + 0.32; Reduction to 32° - 0.03; = 30.215. 
86313.93 
The apparatus was then left during the night fdled with the gas, and on the 
next morning a fresh impulse was given to the pendulum, and the observation 
repeated. 
Observers. 
No. of 
Coincid. 
Thermometers. 
In- 
cluded 
Barom. 
Times of 
Arc registered 
and true Arc. 
Mean 
Interval. 
Correc- 
tion for 
Arc. 
Reduc- 
tion to 
3 6o. 
Corrected 
Vibrations 
at 36°. 
i 
4 
Disapp. 
Re-app. 
Coincidence. 
Mr. 
Taylor/ 
Captain 
Sabine/ 
1 
2 
3 
35 
36 
37 
38 
39 
o 
38.8 
38.9 
o 
38.8 
39.0 
inch. 
29.88 
29.87 
m s 
54 46 
03 12 
11 38 
41 43 
50 09 
58 34 
07 00 
15 26 
m s 
54 58 
03 24 
11 50 
42 07 
50 37 
59 07 
07 36 
16 06 
h m s 
> 0 03 18 
> 4 58 50.5 
Div. o 
0.86= 1.03 
0.30 = 0.36 
1 • 
>506.64 
+ 0.73 
+ 1.20 
86314.24 
38.S5 
29.875; Index + 0.32; Reduction to 32° — 0.025; = 30.17. 
86314.24 
The vibrations in this experiment were as follows : 
T , , f February 9 . . 86313.93; Barom. 30.215 inches. 
In hydrogen gas j Februar ' 10 . 86314 . 2 4. Barom. 30.170 
Mean . 
In atmospheric air, February 9 . 
. 86314.085 ; Barom. 30.1925 
. 86305.57; Barom. 30.193 inches. 
