VOYAGE TO GREENLAND. 
155 
an instrument called a magnitimeter, invented by him 
for measuring magnetic attraction, and finding the 
dip of the needle : some extremely curious experi- 
ments were likewise made on the magnetic laws 
relative to the production, and annihilation of mag- 
netism in iron, by percussion ; and on a recent dis- 
covery of the precise effect on iron bars, becoming 
magnetical by position. It is certainly one of the 
most ingenious instruments I ever saw, and its 
utility was clearly proved to me in repeated expe- 
riments, which, in the science of navigation, must 
be pre-eminently important. The combined attrac- 
tion of the iron in the ship, influencing the compass 
placed near it, was determined also in the most 
satisfactory manner by comparing the polarity of 
the compass in the crow’s nest, with that in the 
binnacle, or place where the compass is kept on the 
ship’s deck. 
There being but very little wind, I went in 
pursuit of unicorns, and to shoot aquatic birds ; 
and I succeeded in procuring some good specimens. 
On my return to the ship, my attention was called 
by Captain Scoresby to an extraordinary instance 
of refraction ; it was visible to the naked eye, but 
with a telescope the effect produced by it was 
astonishing : the atmosphere was particularly clear, 
the sun extremely bright, and a gentle breeze blow- 
ing from the south-west, w^hen, on looking over the 
western horizon, there appeared to ascend from the 
distant surface of the ocean, a perpendicular cliff, 
as if formed of the most regular basaltes of several 
