Date of the Glacial and the Upper Miocene Period. 153 



while the air surrounding the ship was actually 18° below the 

 freezing-point. On another occasion he found the pitch melt- 

 ing on the one side of the ship by the heat of the sun, while 

 water was freezing on the other side from the intense coldness 

 of the air. 



The mean temperature of Van Rensselaer Harbour, in lat. 78° 

 37' N., long. 70° 53' W., was accurately determined from hourly 

 observations made day and night over a period of two years by 

 Dr. Kane. It was found to be as follows : — 



Winter . 



. -28-59 



Spring . . 



. -10-59 



Summer . 



. +33-38 



Autumn . 



. - 4-03 



But although the quantity of heat received from the sun at that 

 latitude ought to have been greater during the summer than in 

 England*, yet, nevertheless, the temperature is only 1°'38 above 

 the freezing-point. 



The temperature of Port Bowen, lat. 73° 14' N., was found to 

 be as follows : — 



Winter 



. -25-09 



Spring . . 



. - 5-77 



Summer . 



. +34-40 



Autumn . 



. +10-58 



Here the summer is only 2° # 4 above the freezing-point. 



If we go to the Antartic regions, where the influence of ice is 

 still more felt, we find the summers even still colder. Capt. Sir 

 James Ross found, when between lat. 60° and 77° S., that the 

 mean temperature never rose even to the freezing-point during 

 the entire southern summer ; and when near the ice-barrier on 

 the 8th of February, 1841, a season of the year equivalent to 

 August in England, he had the thermometer at 12° at noon, and 

 so rapidly was the young ice forming around the ships that it 

 was with difficulty that he escaped being frozen in for the 

 winter. And on the February of the following year, when he 

 again visited that place, he had the thermometer standing at 19° 

 at noon, and the sea covered with an unbroken sheet of young 

 ice as far as the eye could reach from the mast-head. This 

 extraordinary low temperature at that season of the year was 

 wholly owing to the presence of the ice. Had there been no ice 

 on the Antarctic continent, Sir James would have had a summer 



* See Mr. Meech's memoir " On the Intensity of the Sim's Heat and 

 Light," Smithsonian Contributions, vol. ix. 



