1 7 2 PREHISTORIC E UR OPE. 



Scandinavia. The underground forces had been found altogether 

 insufficient to account for those phenomena, and the idea of enor- 

 mously-flooded rivers had likewise failed to afford an adequate 

 solution of the problem. The next theory was that of deluges 

 or inundations which were supposed to have swept over the 

 Continent. This view was ably supported by the well-known 

 experimental geologist Sir James Hall, who, after carefully 

 exploring the neighbourhood of Edinburgh, concluded that the 

 direction of the dSbdde in Central Scotland had been from west to 

 east. No one can read Hall's interesting descriptions without 

 being impressed with his penetration. He was not content 

 merely with tracing out the trend taken by the stones, but he 

 was the first to show that the markings on the rocks had been 

 produced, and that the prominent features of the land itself 

 gave evidence of having been greatly modified, by some force 

 coming from the west. Similar observations carried on in other 

 regions with as much care and intelligence as Hall bestowed 

 upon his work, could hardly have failed to anticipate the theory 

 with which the name of Agassiz is now indissolubly associated. 

 As it was, they soon effected the demolition of the very view 

 in support of which they had been adduced. The great 

 difficulty was how to account for such deluges. Some were of 

 opinion that the inundation was universal, and had its origin 

 in the far north, from which a series of great waves were 

 precipitated over Europe, sweeping large blocks and dSbris and 

 everything before them. Others again, who knew that all the 

 erratics had not travelled in one and the same direction, thought 

 that instead of one great deluge there had been a number of 

 smaller but still powerful irruptions of water. But where did 

 the water come from ? Some said from the sea, others, such 

 as Lamanon and Sulzer, from lakes which had burst their 

 barriers. But where had those lakes existed, the bursting of 

 which could have scattered Scandinavian boulders broadcast 

 over Denmark, Holland, and all Northern Germany? And 

 how had the sea been compelled suddenly to forsake its bed 

 and sweep in giant waves across the Continent ? It was vaguely 



