THE PHYSICAL HISTORY OF THE NORWEGIAN FJORDS. 145 



Ice is not a solid mass of iron, but is, to some extent, plastic, 

 or at all events it follows the conditions of plasticity ; and it is, 

 sometimes, behind a barrier that the greatest heaping up will 

 necessarily take place, and the impetus which could drive forward 

 the enormous masses of ice is a thing that is difficult to understand 

 under any conditions. A mass of ice 6,000 feet thick would 

 require something very considerably thicker to drive it, and to 

 drive it into those narrow valleys; bufc no doubt the fact that it 

 has done so is proof that the ice had enormous fox'ce from behind 

 (vis a tergo) and was capable of giving an impetus to those masses 

 of ice that penetrated the valleys in the form of glaciers. 



I have nothing further to remark, except that the outlets are 

 the principal points of interest, and Professor Hull has shown very 

 clearly how the moraines, aided by the ocean currents, have formed 

 the mariue terraces to which he has referred, so that they may 

 have a foundation of rock ; and yet they have been heaped up, and 

 their height added to, by the moraines left by the glaciers them- 

 selves and the further accumulations of detritus banked up by the 

 ocean currents. 



[Mr. Martin Rouse having called attention to one of the diagrams, 

 Professor Hull further explained the same.] 



Mr. Martiist Rouse. — How are the islands represented there ? 



Professor Hull. — They are not represented there at all. This 

 is the cause of the channel passing between the islands. \_Ex- 

 plaiiiing.~\ 



Mr. Martin Rouse. — Is there generally an opening in that case ? 



Professor Hull. — Oh, yes ; it is generally quite open. [De- 

 scribing.^ 



Mr. Martin Rouse. — The Bay of Bergen : is that in the nature 

 of a fjord ? 



Professor Hull. — Bergen is the place that I could not recall to 

 my mind just now, when I digressed from my paper, and said that 

 the snowfield of the interior could be seen from a point before you 

 get into the harbour of Bergen, at a distance of 100 miles. It is 

 called a fjord ; but I do not know that the Bergen bay, or har- 

 bour, is properly called a fjord. It is one of the channels. 



Mr. Martin Rouse. — You say that fjords have their own winding 

 channels out between islands ? 



Profesaor Hull. — Tes ; they get out one way or another, 



The Chairman. — We are much obliged to Professor Hull for his 



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