100 T. C. Mendenhall—Force of Gravity 
e vibrations at Tokio were all made under nearly the same 
conditions, and for convenience they were reduced to the com- 
mon temperature of 23°°5 and barometer 30 inches. The time 
of vibration of the pendulum at Tokio, under these conditions, 
the mean of all the results, was: 
t,='999834 seconds. 
On the summit of the mountain the barometric pressure was 
tolerably constant at 19°5 inches and the temperature 8°'5, an 
