OF A NORTH-WEST PASSAGE. 
119 
the glasses, and renders the instrument unserviceable till the ice has 1819. 
^ j^ovemb 
been thawed, and the instrument thoroughly cleaned. Our sextants were 1 ' 
somewhat injured, in the cold weather, by the cracking of the silver on the 
horizon and index glasses, arising as we supposed, from the unequal con- 
traction of the two substances. The mercury of the artificial horizons froze 
into a solid mass as we were observing the moon’s altitude in it, although 
the thermometer on shore indicated only — 36°. This was probably owing to 
the mercury having become adulterated by admixture with the lead of the 
troughs, which disposed it to congeal at a higher temperature than the 
freezing point of pure mercury. 
At half-past six P.M., on the 1st of December, part of a circular halo, Decemb. 
whose radius was 22° 52', was observed round the moon, which was near the Wed ' L 
full. Part of a well-defined horizontal circle of white light, passing through 
the moon, extended also for several degrees on each side of her, and in the 
points where this circle intersected the halo, were two prismatic spots of 
light, or paraselenae. In that part of the halo which was immediately over 
the moon, was another spot much brighter ; and opposite to it, in the lower 
part of the circle, another similar but much more faint. About the same 
time, on the following evening, two concentric circles were observed round Thur. 2. 
the moon, the radius of the smaller being 38°, and of the larger 46°. Upon 
the inner circle were four paraselenae, strongly prismatic, situated with re- 
spect to the moon as on the preceding day ; and there was also a faint ho- 
rizontal circle of white light, passing through the moon as before. The weather 
was fine in both these instances, but there was still a sort of haziness in the 
atmosphere which prevented the heavenly bodies being very distinctly seen. 
On the 10th, at two P.M., Captain Sabine observed a small meteor fall in Frid. 10. 
the direction of N.N.W. from the ships, similar in character and appearance 
to that seen on the 28th of November, except that the light was not so vivid, 
and it was extinguished, instead of burning more fiercely, before it reached 
the earth. About this time we were a good deal annoyed for some days 
together by the thermometer continuing higher than usual, the wind being 
from the E.S.E., which caused a considerable degree of dampness between 
decks, in consequence of the ice thawing in every crevice where it could not 
readily be removed in any other way. This annoyance could only be got rid 
of by constant wiping, and by increasing the fires for the time r but, when 
the thermometer fell to 15° or 20° below zero, it again became solid, and 
ceased to be an inconvenience. 
