MILLER- CASELLA THERMOMETER. 181 
schooner yacht Samson , and reached 81° 24' N., with 
an open sea "before him, comparatively free from ice. 
The pack-ice was drifting southwards, and the water 
at the surface was 33° F., while at 300 fathoms it was 
42° F. This fact was observed by Captain Scoresby 
in lat. 78° N., O'TO W., surface 32° F., and at a depth 
of 760 fathoms 38° F. In 1872 the cruise in which 
we had the pleasure of assisting, gave the following 
results. On this occasion the sea was crowded with 
ice, and, as we have said, the ship was beset. 
The ice had evidently required more than one year 
for its formation ; its surface was covered with opaque 
snow, and was generally flat, and in no case rose 
higher than the gangway of the little schooner. 
Owing to the floes presenting a comparatively 
smooth surface, with a total absence of icebergs, we 
were led to form the opinion that no land can exist in 
the vicinity immediately north of Spitzbergen, as the 
.southerly drift would be sure to bring down floating 
bergs, which are always formed in the valleys of 
northern land. 
On this occasion observation with the Miller-Casella 
thermometer confirmed the result of the previous year, 
viz. gradual increase of temperature at great depth. 
On July 12th, when in 80° 17' N., and when the 
vessel was fixed in the ice, the temperature gradually 
