length of the pendulum vibrating seconds. 87 
one knife edge being the point of suspension, the other must 
necessarily be in the centre of oscillation. 
Length of the pendulum vibrating seconds. 
The distance between the knife edges was as follows : 
Inches. Divisions. Inches. 
By the 1st measurement 39,4 + 956,4 7 == 39,44094 
By the 2nd, - 39.4 + 9.5449 = 39>44 o8 6 
By the 3d, - 39,4 + 955,65 = 39,44090 
Mean 39,44090 
Corr. for error in division of the scale ( see 
page 54) - - —0,00005 
39,44085 
Hence, 39,44085 inches may be taken as the distance 
between the knife edges at the temperature of 62 degrees. 
Using the vibrations when the great weight was below , as 
being nearer to the truth than in the other position of the 
pendulum, we obtain the following results. 
Expt. 
Temp. 
Barom. 
Vibrations 
in 24 hours. 
Length of the 
seconds pen. in air 
Corr. for the 
atmosphere. 
Length of the scs. 
pend, in vacuo. 
Difference from 
the mean. 
A 
68,7 
29,76 
86059,42 
39 * 1 33 1 3 
,00544 
39 -I 3857 
+ ,00028 
B 
7 1 ®3 
29,86 
86059,93 
39,13278 
,00544 
39,13822 
— ,00007 
C 
7 i ,4 
29,86 
86057,70 
39,13260 
,00544 
39,13804 
— ,00025 
D 
73.1 
2 9>95 
86056,97 
39,13259 
,00544 
39 U 3803 
— ,00026 
E 
6 9>3 
29,70 
86058,94 
39-13293 
,00544 
39.13837 
+ ,00008 
F 
69»3 
29,70 
86059,01 
39,13298 
,00544 
39, ^842 
+ ,00013 
G 
68,5 
29,70 
86059,22 
39,13286 
,00545 
39.13831 
-f-, 00002 
H 
68,7 
29,70 
86059,25 
39,13296 
,00544 
39,13840 
+ ,00011 
I 
69>3 
29,70 
86058,93 
39-13291 
,00544 
39 , 1383 + 
+ ,00005 
K 
69’3 
29,70 
86058,83 
39,13282 
,00544 
39,13825 
— ,00003 
L 
68,1 
29,90 
86059,22 
39,13271 
,00548 
39,13819 
,00009 
M 
68,4 
29,90 
86059,21 
39,13281 
,00548 
39,13829 
,00000 
Mean 
39, >13829 
