APPENDIX NO. XI. 
405 
No. XI. 
Determination of Temperatures. 
Our expedition was without any special organization for purposes 
of scientific inquiry; and the constant call upon the services of its 
members which the exigencies of our situation made necessary threw 
the duties of observation upon a few of the more intelligent. I could 
not have been justified in imposing such a task on them; but they 
volunteered to perform it, and did so most faithfully. 
Our meteorological observatory was erected on the ice-floe, one hundred 
and fifty yards from the brig. It was enclosed by a system of wooden 
screens, so arranged that the seats of suspension of the several thermo¬ 
meters should be affected by external changes alike, and errors depend¬ 
ent on wind, sun, and local radiation, guarded against as far as possible. 
Such errors as were unavoidable at a single station were still further 
eliminated by corrective observations on the islands and elsewhere. 
These precautions were very necessary. Sir Edward Parry, and 
more recent Arctic voyagers, have shown that there is a difference 
amounting sometimes to two degrees between the temperatures adjacent 
to, and at a distance from the vessel. This was abundantly confirmed 
by our experience. During the intense cold of our winters, the instru¬ 
ments became very impressible to artificial elevation of temperature. 
The approach of the observer, the use of the lantern, the neighborhood 
of articles taken from a heated apartment, Ac. &c. were at once per¬ 
ceptible in our records. 
Except in naval expeditions, Arctic temperatures, whether Asiatic 
or American, have beon recorded with a limited number of instruments. 
The results of these must be received with extreme caution; for the 
differences which alcoholic thermometers exhibit at temperatures below 
the freezing-point of mercury are so varying as to require a large 
number of comparisons, and upon many instruments, to determine their 
proper correction. It was not uncommon for thermometers which had 
given us correct and agreeing temperatures as low as —10° to show at 
—60° differences of from fifteen to twenty degrees. Such too was the 
case with the well-constructed instruments of Sir James Eoss at Leopold 
Harbor. 
To give an example of this, I may refer to the record of six thermo¬ 
meters, suspended near each other as above described, and observed for 
purposes of comparison at noon, February 5, 1854. 
—71°, —G3°, —54°, —53°, —50° and —50°. 
