230 
CAPTAIN SABINE ON THE REDUCTION TO A VACUUM 
the extent that the state of the pump would permit, which left the gauge at 
0.8 inch : when the following observations were made. 
Observer. 
■si 
Thermometers. 
Guage. 
Times of 
Arc registered and 
Mean 
Correc- 
tion for 
Arc. 
Corrected 
Vibrations 
at 36A 
c .5 
fc o 
U 
i 
o 
3 
4 
Disapp. 
Re-app. 
Coincidence. 
true Arc. 
Interval. 
to 36°. 
r 
l 
o 
o 
O 
O 
inch. 
m s 
53 24 
m s 
53 36 
h 
Div. o 
1.02 = 1.22 
o 
3 
39.8 
40.3 
40.3 
40.4 
0.80 
1 49 
10 16 
2 01 
10 28 
i 1 01 55.67 
/ S 
s 
s 
86316.69 
44 
57 07 
05 35 
14 03 
57 27 
05 54 
14 23 
> 507-66 
+ 1.76 
+ 1.94 
Mr. 
Taylor. 
45 
4(5 
39.9 
40.4 
40.3 
40.8 
0.84 
> 7 05 44.83 
0.715 = 0.86 
( 509.284 
+ 0.82 
+2.00 
Gauge 0.82 
88 
10 24 
11 05 
a 
86316.90 
89 
90 
40.1 
40.6 
40.5 
40.8 
0.88 
18 55 
27 26 
57 46 
6 17 
14 50 
19 28 
28 02 
i 13 19 13.33 
0.47 =0.56 
) 
1 510.37 
+ 0.25 
+2.05 
Gauge 0.86 
150 
58 30 
86317.12 
151 
152 
40.1 
40.6 
40.6 
40.8 
0.97 
6 54 
15 23 
> 22 06 36.67 
0.20 =0.24 
> 
Gauge 0.925 
39.97; +0. 
75 = 40.72 
0.872 
86316.90 
A free communication was then established with the external air, and the 
following observations made. 
Observer. 
No. of 
Coincid. 
Thermometers. 
Standard 
Barom. 
Times of 
Arc registered 
and true Arc. 
Mean 
Interval. 
Correc- 
tion for 
Arc. 
Reduct, 
to 36^. 
Corrected 
Vibrations 
at 36°. 
i 
4 
Disapp. 
Re-app. 
Coincidence. 
Mr. 
Tayi.or.' 
1 
2 
3 
24 
25 
26 
o 
o 
inch. 
m s 
52 03 
00 18 
08 34 
1 20 
9 34 
17 53 
m 6 
52 16 
00 30 
08 46 
1 55 
10 10 
18 23 
/ h m s 
[-0 0 24.5 
^ 3 9 52.5 
Div. 0 
0.81 =0.97 
0.225 = 0.27 
i . 
>494.26 
+ 0.56 
+ 2.11 
86306.39 
41.2 
41.0 
30.14 
41.3 
41.6 
30.11 
41.25 
30.125; Capill. + 0.019; Reduction to 32° - 0.031; = 30.113. 
86306.39 
The vibrations in this experiment were as follows : 
In an atmosphere of hydrogen gas 86314.95 ; Barom. 30.120 inches. 
In rarefied hydrogen gas 86316.90; Gauge 0.872 
In atmospheric air 86306.39; Barom. 30.113 inches. 
Whence it appears, 1st, that at nearly equal heights of the barometer (30.120 
inches for the hydrogen gas, and 30.113 inches for the atmospheric air) the 
pendulum made 8.56 vibrations per diem more in hydrogen gas than in atmo- 
spheric air; the temperature of the gas being 39 °.75, and of the air 41°.25. 
Anti 2nd, that the pendulum made 1.95 vibration per diem more in hydrogen 
gas, when the height of the gauge was reduced to 0.872 inch, than when the 
