682 MR DAVID MILNE HOME ON THE BOULDER-CLAY OF EUROPE. 



present course. But its absence would cause the winter temperature of Scotland 

 to fall only by 28° ; and a winter temperature of 10° would not give to us a 

 Labrador climate. Other conditions must therefore be sought for. 



At present the Arctic current, which flows into the North Atlantic, is strong 

 enough to carry icebergs even farther south than latitude 50°. They have been 

 sometimes seen in latitude 40°. Of course, that Arctic current cannot cross the 

 Atlantic and float icebergs on Great Britain, because the Gulf Stream would 

 intercept it. But suppose the Gulf Stream not to run, as it now does, in a N.E. 

 direction towards Norway. Suppose that, by the Isthmus of Panama being 300 

 feet lower than at present, the equatorial current, instead of being deflected by 

 the American coast northwards, were to flow into the Pacific, and find its way 

 through Behring's Straits, where there is now a current running from the Pacific, 

 the Arctic current which now flows into the North Atlantic would not only have 

 no Gulf Stream to interrupt it in its progress towards Europe, but would 

 be immensely augmented in volume and speed. The stream passing through 

 Behring's Straits would carry with it a tendency to move eastwards, having 

 acquired that tendency in equatorial regions by the earth's diurnal rotation. 



If high land nearer than Greenland is thought necessary, evidence is not 

 awanting to justify that supposition. 



In the first place, it is well ascertained that Greenland at its southern extremity 

 has long been sinking, whilst its northern parts are rising.* Dr Kane and Dr 

 Hayes endeavoured to find where the axis of oscillation is situated. The one 

 gives 76° of latitude, the other 77° of latitude. Both observers were struck with 

 the fact, that whilst to the north of this supposed axis, lines of raised beaches 

 were visible, none were visible to the south of it. Dr Kane saw and counted no 

 less than forty-one beach lines, at a part of the coast in latitude 78° 30', or 

 about 150 miles to the north of the axis; the highest being 480 feet above the sea. 

 Now it is not unreasonable to suppose, that on the south side of the axis of oscilla- 

 tion, the sinking would be at the same rate as the rising on the north ; in which 

 case, what is now the southern extremity of the continent, which is in latitude 

 60°, and therefore about 1000 miles from the axis of oscillation, must, before the 

 sinking began, have been 3200 feet higher than it is at present, and a great 

 deal of what is now sea-bottom to the S. and S.E. of Greenland must have been 

 dry land. 



The probability of changes having occurred in the bed of the North 

 Atlantic is all the greater on account of the volcanic convulsions to which it has 

 frequently been subject, of which not only Iceland is a proof, but the igneous 



* Dr Hjaltelin of Iceland, in his letter to Mr R. M. Smith, quoted on page 667, mentions — 

 " I have seen the secular elevation of the northern shores of this island ; and it is not unlikely that 

 the north coast of Greenland is in a similar state." Therefore it is probable that the north extremity 

 of Iceland rose up simultaneously with North Greenland. 



