12 
MR. H. M'LEOD ATSTD LIEUTENANT G. S. CLARKE ON THE 
Mean 
For 1° C. 
From determinations ; 
•000116 
15-01 
and 16-31 
•000111 
5? 
16-69 
•000111 
19-75 
•000110 
5? 
21-16 
•000109 
24-29 
•000110 
25-69 
•000111 
Starting from the determinations made 
For i° c. 
•000110 
•000110 
•000109 
•000110 
•000111 
•000123 
Mean '000112 
at the highest temperature, we have :—- 
From determinations at 
25'69 and 15'01 
„ 16-31 
„ 16-69 
„ 1975 
„ 2116 
„ 24-29 
Rejecting the last number as being obviously too high, the mean of the other five 
is -000110. 
Determinations have been made with a new set of Koenig’s forks, obtained for us by 
Mr. Ladd last year, and stated to be correct at 15° C.* The following vibration 
numbers were found, and the corrections for temperature were made by the use of the 
coefficient '00011 for each degree centigrade ; — 
* We afterwards heard that Mr. Kenig considered them to be correct between 19° and 20° C. 
