KECOUD AND DISCUSSION OF TEMPERATURES. 



The vessel of the exploring expedition entered the winter quarters at Van Rens- 

 selaer Harbor, on the eastern trend of the coast of Gx'eenUind from Smith's Strait, 

 on the 8th of September, 1853.^ From the first of that month, she had not changed 

 her position a mile, and the record and discussion of the observations for tempera- 

 ture will therefore commence, in the present paper, with September 1st, and be 

 continued to January the 24th, 1855. This is the last day of entry in the original 

 log-book in my possession. The temperatures after that date, and extending to 

 the last of April, 1855, have been taken from Appendix No. XII. of the second 

 volume of the narrative of the expedition. 



The bay, surrounded by cliffs, is open towards the north and west, and the harbor 

 is in latitude 78° 37', and in longitude 70° 53'- west of Greenwich. 



By the 28th of September, 1853, the erection of the meteorological observatory 

 on the floe had been completed. It was a wooden structure, placed 140 yards from 

 the ship, on the open ice-field, latticed and pierced with auger-holes on all sides, so 

 as to allow the air to pass freely, and was firmly cemented to the ice at the base by 

 freezing. To guard against the fine and almost impalpable drift which insinuates 

 itself everywhere, and which would interfere with the observation of minute and 

 sudden changes of temperature, a series of screens were placed at right angles to 

 each other, so as to surround the inner chamber. The thermometers were sus- 

 pended within the central chambers ; a pane of glass permitted the light of the 

 lanterns to reach them from a distance, and a lens and eyeglass were so fixed as to 

 allow observing the instruments without going inside the screens. One of them — 

 a three-feet spirit standard, by Tagliabue, of New York, graduated to 70° minus — 

 was of sufficiently extended scale to be read, by rapid inspection, to tenths of a 

 degree. It was not desired absolutely to neutralize the influence of the winds, but 

 to make the exposure to them so uniform as to give comparable results for every 

 quarter of the compass.^ 



The expedition was well supplied with thermometers. Thirty-six mercurial 

 thermometers were received from the National Observatory at Washington, D. C. 

 Their corrections near the freezing point were determined at the observatory, and 



• See Narrative of the Expedition, Vol. II. p. 394. 



' Tlie result of a new reduction of the moon culminations. 



' See Narrative, Vol. I. p. IIT. 



