24(3 PROFESSOR JAMES GE1KIE, LL.D., D.C.L., F.R.S., ETC., ON 



must be admitted that considerable submergence of the land 

 took place in glacial times. The advocates of the earth- 

 movement hypothesis naturally attach much importance to 

 this evidence. If it can be shown that the crust of the earth 

 has been depressed in northern regions to depths of 1,500 to 

 2,000 ft. it is less hard to believe that at other times it may 

 have been uplifted to as great an extent above its present 

 level. We have seen, therefore, that they do not hesitate to 

 infer that, in early glacial times, North America and the 

 north-western regions of Europe, if not a still larger area of 

 that continent, stood some 3,000 ft. or so higher, and that 

 those regions subsequently became submerged to the depths 

 indicated by the raised beaches. The amount of subsidence 

 in New England must therefore have amounted, according 

 to this view, to more than 3,000 ft., say 3,200 ft, in Canada to 

 3,500 ft., in Labrador and the far north to 4,500 or 5,000 ft. 

 In North- West Europe likewise the earth-movement must 

 have ranged between 3,500 and 3,600 ft. Fortunately for 

 mankind, our continents, when re-elevation ensued, were not 

 uplifted to the great height which they are supposed to have 

 attained at the beginning of the glacial period. 



The remarkable association of evidence of glaciation with 

 proofs of submergence has long been noted by geologists, 

 and various attempts have been made to show that the 

 drowning of the lands may have been caused by the great 

 ice-sheets. Thus Croll and others have maintained that vast 

 accumulations of ice in northern latitudes would tend to 

 displace the earth's centre of gravity, and thus cause the sea 

 to rise on the glaciated hemisphere. This is probably a vera 

 causa, but it is very doubtful if it can account for the extreme 

 submergence indicated by the more elevated raised beaches. 

 Again, it has been supposed that the attractive influence of 

 the great ice-sheets would bring about a deformation of the 

 sea-level, but, as Dr. Drygalski has shown, this cause is quite 

 insufficient to account for the amount of submergence which 

 is known to have taken place. But the view which has met 

 with most acceptance is that advocated by Mr. Jamieson, 

 who thinks that the earth's crust was simply pressed down 

 under the weight of overlying ice-masses. Even those 

 geologists who most distrust Sir William Thomson's con- 

 clusion that the earth is substantially solid may well hesitate 

 before they admit the feasibility of Mr. Jamieson's hypothesis. 

 Were the crust so readily deformed as he supposes, it is hard 

 to understand how great mountain-chains can be supported 



