290 On the Glaciers and Climate of Iceland. 



whilst, according to observations made during a space of five 

 years, the mean temperature of the sea may be taken to be 

 5-42° centigrade. The mean temperature for the whole year 

 at Akureyre, on the other hand, is, according to Scheel, 0-58° 

 centigrade. If we compare these numerical data partly with 

 one another, and partly with the positions of the isothermal 

 curves, we readily an'ive at the following conclusions. 



The diminution of the mean temperature by 4 degrees from 

 Eeykjavik to Akureyre is very striking, these two places dif- 

 fering in latitude by only two and a half degrees. Accord- 

 ing to the representation given in Berghaus's Physical Atlas, 

 there is, on the whole northern hemisphere, no region where 

 the belt contained between the isothermal lines of 0° and 5° 

 centigrade is so nan*ovv as in Iceland. Besides this, the 

 mean temperature for both places is unusually high with re- 

 ference to the geographical latitude. 



This last remark applies, in an especial degree, to Reyk- 

 javik [and Southern Iceland ; for at no other place in the 

 world does the isothermal line oi^° centigrade rise to a lati- 

 tude of more than 64° (the latitude of Reykjavik), whilst in 

 Europe it sinks below the 60th, and in Upper Asia even below 

 the 49th, degree of latitude. The isothermal line of 0° cen- 

 tigrade has a form somewhat less favourable for the climate 

 of Iceland ; for although, no doubt, it scarcely touches the 

 extreme north of Iceland, yet near the Scandinavian North 

 Cape it passes much farther northward, reaching the 71st 

 degree of latitude. "With the exception of this single point, 

 there is, in the whole northern hemisphere, no region where 

 this curve cuts the polar circle — no milder climate for so 

 high a latitude. 



If we compare the temperatures of the sea and the above- 

 have not yet been published ; but they were kindly communicated to me by 

 Dr Petersen of Copenhagen, to whom I am also indebted for the observations 

 of Captain Scheel, which were made at Akureyre. 



In A. von Humbjldt's Central . Asia, and Berghaus's Physical Atlas, the 

 mean temperature is deduced from the observations of only the first tvro years. 

 The observations on the temperature of the sea were made by Thorstensen, in 

 the mornings between five and eleven o'clock. The mean calculated by me for 

 the whole year is perhaps rather too small, since the maximum temperature of 

 the sea did not occur before half-past one in the afternoon. 



