AND ITS TEMPERATURE CORRECTION. 



69 



Table I. 



Observations for the Time of Vibration of the Balance Needle in a Vertical Plane, 

 before and after excessive Vibrations. 



5. 2d, The time of vibration in a vertical plane depends, to a considerable 

 extent, on the magnitude of the arc of vibration. 



3d, For the same arc, the time of vibration is greater, if it belong to a series 



• This is the only case in which I determined, at the instant, the effect of excessive vibration on the posi- 

 tion of the needle ; the effect, though small, is considerable, when compared with the hourly changes ; (ot 

 several hours before this vibration, the magnet had not changed its position. 



VOL. XVI. PART I. 



S 



