508 The Astronomer Royal on a recent Magnetic Disturbance. 



m s ° ' 



50 37 p.m., Gottingen mean time, theodolite read 246 30 



8 

 26 

 32 

 25 

 46 

 37 

 28 

 43 

 51 

 53 

 39 

 46 

 30 

 47 



It is to be remembered, that increasing readings denote that 

 the north end of the needle moves towards the east. 



Vertical-Force Magnetometer. — The vertical-force magneto- 

 meter was as much affected as the declination instrument. 

 The disturbances of its vibrations were very similar, except 

 that it was frequently much longer in the stationary state, its 

 times of rest varying from 5 s to 2 m ; at the end of each of these 

 it jumped on, then was again still, and so on. 



This instrument had been much affected early in the morn- 

 ing; the extent of its excursions being between 37 d *9, and 

 44 d, l on the scale. The following are scale-readings, com- 

 mencing with noon: — 



