81 



and 



36c 3X5-25X-0674 



254.7^ 



1 



1029 



; whence 



2547 1726 



360° are performed by the pendulum without ellipticity in 28*75 hours, 



and 12°-5 in 1 hour. 



We have thus from the Minster experiments, — 

 a. Uncorrected for Ellipse, 



Exp. 2. 4. On N. and S. line 



15-3 + 12-0 



13°-65 in one hour. 



1. 3. On E. and W. line ^^'^t^^'^ = 12°-60. 



Exp. 5. On E. 



/3. Corrected for Ellipse. 

 and W. line 



12-50. 



Experiments in my House, 



After many failures the apparatus became tolerably efficient, with 

 a pendulum of 68*7 inches, as deduced from the vibrations, 22*64 in 

 a minute. The balls used were a prolate spheroid weighing 6\ lbs., 

 and a globe weighing only 1 ^V^b. I have obtained the best results 

 with the smaller weight. The suspensions have been silk, gutta 

 percha, and various contrivances of points and sockets of agate, brass 

 and steel. The best results have been obtained with gutta percha, 

 and sockets of agate and steel. The arc mostly used was from 16 

 to 20 inches. The experiments were seldom continued beyond half 

 an hour. By that time the chord of vibration was reduced to about 

 7 or 8 inches, and the errors of experiment were thought likely to be 

 too great, with so short a radius, if longer continued. The ball, in 

 whatever direction swung, presents the same face to the same side 

 of the room. 



Direction at origin. 



Time. 



Deviation. 



Chord. 



Ellipse. 



Left. 



Right. 





Direction. 



Minor axis. 



(6). N.E. and S.W. .| 



m 

 

 15 

 30 









3| 

 7 



in. 

 18 



No 

 None ob 

 None ob 



ne. 



served, 

 served. 



(7). N.W. and S.E. | 







45 





8 



18 



No 

 None ob 



ne. 



served. 







(8.). N.E. and S.W. | 





 15 

 30 





3 

 6 



18 



No 

 None ob 

 Left. 



ne. 



served, 

 -i^inch. 





4 



(9). N.W. and S.E. | 



9 

 15 

 30 





3 



5-55 



18 



No 

 None ob 

 Left. 



ne. 



served. 

 Minute. 











Proceedings of the Royal Society. Vol. VI. No. 81. 6 



