90 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [DcC. 17, 



The Gulf-stream, flowing through the Straits of Bahama, and 

 afterwards, in its north-eastern direction, towards the North Sea and 

 the coasts of Europe, is a current reflected from the shores of the 

 Gulf of Mexico in consequence of the impossibility of its continuing 

 the north-western course by which it reaches the Gulf. But in the 

 case now supposed, a direct opening would be made exactly in the di- 

 rection which the current would continue to follow if uninterrupted. 

 Its continuance to the Arctic Sea, and its non-reflexion through the 

 Straits of Bahama, would be the obvious consequences of the de- 

 pression of the continent of North America. It would thus lose all 

 sensible influence on the coasts of western Europe, but it would ne- 

 cessarily increase the temperature along its new course, and especially 

 in the cold region of north-western America towards the present 

 shores of the Arctic Sea. The north-eastern portion of the present 

 continent would probably be much less afl'ected by it. 



34. It is probable that every great oceanic current must have its 

 counter-current. Now, if the mass of water constituting the Gulf- 

 stream were poured, as here supposed, directly into the Arctic Ocean, 

 the only course, which any great counter-current from that ocean 

 could follow, would seem to be through the North Sea intervening 

 between the coasts of Norway and Greenland, and across the sub- 

 merged portion of northern Europe. There would in fact be no 

 other considerable opening from the north ; for even, if we suppose 

 the low lands of northern Asia to be submerged, the mountain-ranges 

 of that region would still oifer an insuperable bar to any egress, ex- 

 cept in the direction above indicated, for the waters of the Arctic 

 Ocean. The opening through Behring's Straits would probably not 

 be worthy of notice. These considerations appear to me to increase 

 considerably the probability that this diverted course of the Gulf- 

 stream would be attended by a cold current over the region now oc- 

 cupied by the continent of northern and western Europe. 



35. The theory which I have here proposed respecting the diver- 

 sion of the Gulf-stream, is not to be regarded as resting on an hypo- 

 thesis framed simply to enable us to account for a particular class of 

 phsenomena. I regard it, on the contrary, as resting on a necessary 

 inference from the submergence of the North American continent ; 

 for, I repeat, if that continent were submerged to the depth implied, 

 as I believe by the most conclusive geological evidence, the course of 

 the Gulf-stream could be no other than that which I have assigned 

 to it. It is necessary, according to this view of the subject, to 

 suppose this to have been the course of the current during the period 

 of greatest cold in Europe, but it is by no means necessary to extend 

 the supposition to the whole period of submergence of a great por- 

 tion of the American continent. Many of the glacial phsenomena of 

 that region might be produced during its partial submergence, before 

 the depression of the land was sufficient to admit the current to the 

 Arctic Sea, or after its course had been again impeded, or altogether 

 arrested, by the partial subsequent elevation of that continent. 

 During the uninterrupted course of the current to the north, it would 

 doubtlessly, as I have above remarked, increase, and probably very 



