154 
TEMPERAT U H E S. 
to find the platform on which the observer stood full 
fifty degrees lower, (—20°.) Our astronomical ob¬ 
servations were less protracted, but the apartment in 
which they were made was of the same temperature 
with the outer air. The cold was, of course, intense: 
and some of our instruments, the dip-circle particu¬ 
larly, became difficult to manage in consequence of 
the unequal contraction of the brass and steel. 
On the 17th of January, our thermometers stood 
at forty-nine degrees below zero; and on the 20th, 
the range of those at the observatory was at —64° 
to —G7°. The temperature on the floes was always 
somewhat higher than at the island; the difference 
being due, as I suppose, to the heat conducted from 
the sea-water, which was at a temperature of 
+ 29°; the suspended instruments being affected by 
radiation. 
On the 5th of February, our thermometers began to 
show unexampled temperature. They ranged from 
60° to 75° below zero, and one very reliable instru¬ 
ment stood upon the taffrail of our brig at —65°. 
The reduced mean of our best spirit-standards gave 
—67°, or 99° below the freezing-point of water. 
At these temperatures chloric ether became solid, 
and carefully-prepared chloroform exhibited a granu- 
of them. In addition to these, we had weekly determinations of varia¬ 
tion of declination, extending through the twenty-four hours, besides 
observations of intensity, deflection, inclination, and total force, with 
careful notations of temperature. 
