634 



Dr. W. B. Carpenter on the [June 13, 



of 70°), and then turns southwards along the land, keeping within the 

 coast-line of Russian Lapland, and passing across the narrow throat of the 

 White Sea. The summer Isotherms of 50° and 45|° cross the mouth of 

 Baffin's Bay, and then follow the curve of the coast of Greenland towards 

 Iceland; when approaching which they turn eastwards, the line of 50° 

 striking the land at Stykkisholm on the N.W., while the line of 45 §° passes 

 altogether to the north of the island. To the east of Iceland the Isotherms 

 take a southerly bend, apparently under the influence of a drift of ice from 

 the Polar Sea ; hut soon turn northwards again, — the line of 50° running 

 nearly parallel to the coast of Norway as far as the North Cape, and then 

 turning southwards along the coast of Russian Lapland, so as to cross the 

 mouth of the White Sea to the base of the Kanin Peninsula ; while the line 

 of 45^° runs parallel to this as far north as Lat. 72|°, and then turns south- 

 wards, still retaining the same parallelism, so as to strike the coast of Russia 

 beyond that peninsula. Still further north, we find the summer Isotherms 

 of 41° and 36^° showing a nearly W. to E. direction until they have passed 

 the meridian of 10° W. a and then suddenly turning northwards ; the line 

 of 36|° passing up to the west of Spitzbergen as far as 82° N., and also 

 extending itself irregularly eastwards along the parallel of 75° as far as 

 Nova Zembla. 



159. The course of the winter Isotherms of 45 41°, 36"^°, and 32°, 

 as shown in Dr. Petermann's Chart, is no less significant ; for they all 

 turn sharply to the North on the eastern side of the Banks of Newfound- 

 land, cross the entrance of Baffin's Bay, and then keep a course of general 

 parallelism to the coast of Greenland, crossing the meridian of 30° W. at 

 almost equal intervals. The winter Isotherm of 45J° follows almost 

 exactly the course of the summer Isotherm of 54^-° as far as the Shetland 

 Islands : but it then turns back on itself so as to form a loop, passing south- 

 wards along the Western Hebrides towards Belfast. The course of the 

 winter Isotherm of 40° in like manner at first bears a general correspond* 

 ence with that of the summer Isotherm of 50°, skirting the south coast of 

 Iceland, and then passing N.E. in the channel between Iceland and Nor- 

 way ; but in Lat. 67^-° N. it also returns in a loop, which brings it back 

 to the east coast of Scotland. The winter Isotherm of 36 i°, again, corre- 

 sponds very closely with the summer Isotherm of 45°; passing through 

 Iceland, and then keeping a N.E. course which carries it far to the north 

 and east of the North Cape, when it, too, forms a loop bringing it back 

 to the coast of Russian Lapland. Finally, the winter Isotherm of 32° 

 proceeds along a similar course from the Banks of Newfoundland to the 

 northernmost point of Iceland, and then onwards towards Jan May en, 

 beyond which it has not been traced. 



1G0. That this remarkable course both of the Summer and of the Winter 

 Isotherms can only be accounted for by a N.E. flow of warm water, I am 

 as strongly convinced as Dr. Petermann can be : and that this movement 

 must be something very different from a mere surface-drift, seems to me 



