354 ACCOUNT OF THE ARCTIC HEGIONS, 



of the truth ; for when we reach the regions of per- 

 petual ice, a remarkahle anomaly is discovered, the 

 mean temperature falling below the estimation by 

 the formula, at once 17° ! As this fact is of much 

 importance in generalizing our knowledge of the 

 temperature of the globe, I have subjoined to this vo- 

 lume a series of observations on the temperat'dre, &c. 

 of the polar regions, conducted with care during 

 twelve successive voyages to the Greenland sea *, 

 from whence I am enabled to deduce the following 

 conclusions as to the probable temperature of the 

 polar regions, in different latitudes, during every 

 month of the year. 



The mean temperature of the months of April, 

 May, June and July, are satisfactorily derived, di- 

 rectly from the means of the latitudes and of the 

 observations of temperature contained in the Appen- 

 dix ; — but the mean temperature of the whole year, 

 and of the winter months, wherein no observations 

 in such high latitudes have yet been made, can only 

 be ascertained from analogy. From the examination 

 of numerous thermometrical registers, particularly 

 one consisting of 54,750 observations made in a suc- 

 cession of fifty years, at Stockholm, the valuable re- 

 sults of which are publishedin the Annals of Philoso- 

 phy, (vol. i.p. 113.) it would seem, that the month of 

 April (Old Style) affords a temperature which, in 

 northern latitudes, is the mean of the year ; or that 

 a month, of which the middle is called the 27th-28th 



• Appendix, No. I. 



