ATMOSPHEltIC llEEIt ACT IONS. 
163 
the latitude of 71°, I thought it advisable to take 
advantage of a favourable change of wind, and re¬ 
turn to that parallel. W-e accordingly bore away 
to the south-westward, so as to keep a more east¬ 
ern meridian than that on which we ascended to¬ 
wards the north. Four ships followed our exam¬ 
ple, a considerable number proceeded on a more 
westerly course, while the remainder hove to, ap¬ 
parently for the want of a determination. 
The next day, July 18th, we accomplished a dis¬ 
tance of about 100 miles towards the SW. and W. 
The land was not seen, though the weather was 
perfectly clear, until the evening, when the tops of 
the mountains appeared above the refracted ice. 
As soon as the fog had cleared away, on the 
16th, the influence of the sun that was then most 
powerful, soon began to produce a rapid evapora¬ 
tion from the surface of the sea and ice,—this gave 
rise to the optical phenomena of unequal refrac¬ 
tion, which continued to operate with ever vary¬ 
ing effect, for sixty or seventy hours. At one pe¬ 
riod (about 10 I*, nr. of the 16th) the phenomenon 
was so universal, that the space in which the ship 
navigated seemed to be one vast circular area, 
bounded by a mural precipice, of great elevation, 
of basaltic ice. In some places, where water, in¬ 
stead of ice, was seen through the refraoting mo- 
L 2 
