NO. 7.] INTRODUCTION. 9 
vatory was completed, an ice pillar was introduced into it, 1.4 metres 
high; and on the top of the pillar a block of wood was frozen fast, and the 
instrument screwed to it. 
As a defence against bears during the taking of observations, a weapon 
was always at hand, generally a revolver, which was either stuck vertically 
into a hole in the ice between the legs of the stand, perpendicularly below 
the centre of the instrument, or lay horizontally in the same place with its 
butt-end pointing westwards. Several observations were made with the re- 
volver in various positions, without any proof being obtained of any decided 
influence on the readings. When the ice observatory was taken into use, 
the revolver was laid on the ice to the north, at a distance of 3 metres from 
the instrument, on a level with the foot of the pillar, and, as before, with 
the butt-end towards the west. When Lieut. Scorr-HAnsen had a different 
weapon with him, it lay on the ice at a distance of about 30 or 40 paces 
from the instrument. 
