100 AKSEL S. STEEN. TERRESTRIAL MAGNETISM. [NORW. POL. EXP. 
this time until October 3rd, the double declination needle was used for 
quieting the magnet during the vibration observations; and during the vibra- 
tions themselves, it was standing in a vertical position in the revolver’s 
place. On the 4th and 17th October, 1895, several series of vibration obser- 
vations were made with magnet V, to ascertain the influence of the decli- 
nation needle, when placed in the above position. 
H 
The declination-magnet in 
the revolver’s place b 
| The declination 
a c i 
: magnet laid 
With the north | With the south mail 
end upwards | end upwards 
0:04846 | 
004915 
004915 
4! 97" py. m. 
4 58 
5 25 
5 47 
Mean 004743 0:04670 
The differences of the means are: 
a—b C—O 
Oct. 4th. . . . —0-00052 + 0:00009 
Sith eee 0: 00002000071 
As will be seen from the results here given of the observations, no 
decided effect upon the vibration observations, either from the revolver or 
from the declination magnet in the above-mentioned positions, can be proved. 
