6 



THE NOETH-EAST ATLANTIC. 



boat manned with a strong crew can scarcely make head against them.* These 

 currents send southwards continuous lines of icebergs with their loads of detritus, 

 which sink to the bottom during the summer at the contact with the southern 

 branch of the Atlantic waters. The vast bank stretching north-west of Bear 

 Island seems to be an immense submarine moraine similar to the bank of 

 Newfoundland."!" But beyond those rocky dej)osits the polar stream continues to 

 flow towards the warmer waters from the south, interpenetrating them with currents 

 of cold water like those met with in the regions east of Iceland. 



The arctic section of the East Atlantic is thus on the whole marked off with 

 sufficient clearness by the form of its submarine bank, by the general movement of 



Fig. 2. — Isothermal Lines op the North -East Atlantic in July. 

 According to Mohn. Scale 1 : 28,090,000. 



,,WP 





o''cI-G 



500 Miles. 



its waters, and by the meteorological conditions. The European waters are almost 

 entirely occupied, at least in summer, by the tropical currents. Doubtless in 

 Avinter the warm stream, although much more regular in its movements than 

 during the hot season, is everywhere driven far to the south, the water north of 

 Jan Mayen and Bear Islands being below freezing point, and almost entirely filled 

 by icebergs. Still the mean temperature of the North-east Atlantic is at all 

 times much higher than that found elsewhere in the same latitude. The mean 

 difference from July to January between cold and heat for any given point in this 



* LamoDt, Masqueray, Bulletin de la Sociitê de Géographie, October, 1S72. 

 t Petermann's Mittheilungen, iv. 1870. 



