Ixiv PROCEEDINGS OP THE GEOLOGICAL SOCIETY. 



Gulf of Mexico. But when that continent was submerged, as above 

 supposed, the current would necessarily continue its north-westerly- 

 course, and probably along the foot of the Rocky Mountains directly 

 into the Arctic Sea. This is the manner in which I conceive the 

 Gulf-stream to have been diverted from the shores of western Europe. 

 This diversion of the current is not to be regarded as a mere hypo- 

 thesis adopted to account for any particular fact, but as a necessary 

 consequence of that submergence of the North American continent. 



Again, if this enormous current discharged itself into the Arctic 

 Sea, it would seem extremely improbable that it should not give rise 

 to some great determinate counter-current out of that sea. Now it 

 appears highly probable that a considerable tract of land must have 

 existed at the period of which we are speaking in the present region of 

 north-eastern America, and Greenland. If this were the case, the only 

 practicable outlet for a great current from the x^rctic Sea would be 

 across the submerged portion of northern Europe, or along the present 

 North Sea, between Greenland and Norway ; for the passage through 

 Behring's Straits, even with a considerable subsidence of the land on 

 either side, would be neither sufficiently wide nor deep to form a con- 

 siderable outlet. Under such circumstances, it would scarcely seem 

 more necessary that the Gulf-stream should hold its original north- 

 westerly course over the submerged continent of America, than that 

 it should complete its circuit by passing through the Arctic Sea, and 

 returning to the Atlantic across the submerged land of Europe, as it 

 now completes a more circumscribed circuit by being constrained to 

 pass along the northern portion of the Atlantic itself. 



The effect of this diversion of the Gulf-stream from its present 

 course, would not be less remarkable in elevating the temperature of 

 the northern shores of America and Asia, than in reducing that of 

 western Europe. I have shown that the mean annual temperature 

 of Iceland is increased 18° or 20° F., and the January temperature 

 34°, by the influence of this important current. Now the distance 

 from the Gulf of Mexico to Behring's Straits is very little greater 

 than the distance between that gulf and Iceland, and the passage of 

 the stream along the flanks of the Bocky Mountains would be more 

 direct, and probably less impeded by counter-currents than it is at 

 present in its transatlantic course. There can be no reasonable doubt, 

 therefore, of its raising the temperature of the north-western coast of 

 America, from the Mackenzie river to Behring's Straits, by an amount 

 at least equal to that by which it now elevates the temperature of 

 Iceland. Further, it is highly probable that the principal course of the 

 current in the Arctic Sea would not be far from the coasts of northern 

 Asia, the temperature of which would thus be affected in a manner 

 similar to that of the coast of America eastward of Behring's Straits, 

 although in a smaller degree for greater distances on the west of the 

 Straits. The temperature of winter immediately east of the Ural Moun- 

 tains would also be considerably moderated, as already stated, by the 

 extension of the European sea towards their western flanks. The 

 climate of the low lands of northern Asia would thus differ from the 

 present climate of that region, as much as the existing climate of the 



