8 Mr Barlow on the Effect of Rotation on the Needle. 



Experi- 

 ments. 



1 



2 



General mean deflection, 28° 24 ; . 



With the Shell 

 Rate of Rotation 640 per minute. 



Reading of 



the needle 



with the 



shell at rest. 



30' 















30 



30 



30 







+0° 

 



+ 1 







— 



+o 

 +o 







Deflection 



turning to 



the left. 



14° 45' 

 15 

 15 30 

 15 30 

 15 

 15 30 

 15 

 15 



Deflection 

 turning to 

 the right. 



15° 

 15 

 15 

 15 

 15 

 15 

 15 

 15 



W 











30 







30 











Mean de- 

 flection. 



14° m 



15 



15 15 



15 30 



15 



15 30 



15 



15 



General mean deflection, 15° 5 ; 



Under like circumstances, therefore, the deflection of the 

 ball was - 28° 24' 



Do. of the shell - - - 15 5 



Which is very nearly in the proportion of their respective 

 masses. 



These results were observed under more favourable circum- 

 stances than those I sent to M. Poisson ; and although, from 

 the heavy and cumbrous nature of the apparatus, they can- 

 not be said to possess all that accuracy which is necessary for 

 submitting a refined mathematical theory to experimental test 



