No. 8.] PENDULUM OBSERVATIONS. 5 
In all the observations except the first, the half-seconds pendulum clock, 
Hawe xk No. 3, which worked the coincidence apparatus, was compared with the 
mean-time chronometer, Honwit, either directly or indirectly by means of the 
sidereal chronometer, FropsHam. In the first observation, at Khabarova, the 
mean-time chronometer KuTTER was used instead of the Honwt. The Hawelk 
was compared with the chronometer every time before and after the observations. 
Professor GEELMUYDEN, who has worked out the time observations taken 
during the expedition, has stated that the rate of Houwii may be calculated 
according to the formula 
S. Ss. 
Daily acceleration = 0:446 — 0:080 4, 
where ¢ is the temperature. 
From this we obtain the following values for the rate of Honwit on the 
days on which observations were made: 
July 30 
January 16 
March 16 
June 8 
>» 10 
Py ali 
November 14 
> 93 
January 16 
April 29 
» 30 
Professor Geelmuyden remarks that the above temperatures are taken 
from registered curves for the lime of observation; but as the thermograph 
stood somewhat higher than the chronometer, and the comparison between 
it_and the thermometer on the chronometer-shelf was made only once a day, 
the temperature cannot be given more accurately than to the nearest whole 
degree. He considers, however, that the actual rate cannot have varied more 
than + 0°.1 from the above. 
As regards the chronometer, Kutter, used on July 30, 1893, I have re- 
ceived the following comparisons between it and the chronometer, Hohwii. 
