NO. 8.] 



PENDULUM OBSERVATIONS. 



In all the observations except the first, the half-seconds pendulum clock, 

 HAWELK No. 3, which worked the coincidence apparatus, was compared with the 

 mean-time chronometer, HOHWU, either directly or indirectly by means of the 

 sidereal chronometer, FRODSHAM. In the first observation, at Khabarova, the 

 mean-time chronometer KUTTER was used instead of the HOHWU. 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 HOHWU may be calculated 

 according to the formula 



Daily acceleration = : 446 : 080 1, 

 where t is the temperature. 



From this we obtain the following values for the rate of HOHWU on the 

 days on which observations were made: 



Professor Geelmuyden remarks that the above temperatures are taken 

 from registered curves for the time 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 O s .l 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, Hohwti. 



