28 MR. J. H. POYNTING ON THE 



Time of Vibration at Commencement. 



No. of 

 vibration. 



Observed time of 



passage of pointer 



through resting- 



point. 



6 2 

 ^.-2 



Observed time of 



passage of pointer 



through resting- 



point. 



Time of 10 

 vibrations. 



o 



2 



4 

 6 



Poi?iter apparen 



h. m. 8. 

 II 15 36 

 II 16 1 

 II 16 26-5 

 II 16 52 



IVTean valiio of td 



tly moving 



10 

 12 



14 

 16 



irihratinns 



from left to right. 



h. m. s. 

 II 17 43 

 II 18 8 

 11 18 335 

 II 18 59 



8. 

 127 

 127 

 127 

 127 



127 







I 

 3 

 5 

 7 



Pointer apparen 



II 15 49 

 II 16 14 

 II 16 39-5 

 11 17 5 



Mean value of 10 



tly moving from right to left. 



II II 17 56 

 13 II 18 21 

 15 II 18 46 

 17 II 19 11-5 



vibrations 



127 

 127 

 126-5 

 126-5 



126-75 









Mean of means = 126-875 ; /i= 12-6875^ 

 Determination of Deflexion n. 



Excess 

 weight 



Extremities 

 of oscillation. 



Eesting- 

 point. 



Mean of preceding 

 and succeeding 

 resting-points. 



Deflection 

 due to 

 excess. 



Added 



109 



96 

 109 



102-5 







Removed . . . 



93 



40 

 92 



66-25 



102-25 



36 



Added 



152 



53 

 150 



102 



66-75 



35-25 



Bemoved . . . 



80 



55 

 79 



67-25 



102-5 



35-25 



Added 



147 



60 



145 



103 







Mean value of ^ = 35-83, 



