114 PROCEEDINGS OF THE COTTESWOLD CLUB 



may be mentioned. For a considerable distance along 

 the foreshore on the sheltered side of the bay there runs 

 a ridge of boulders just about the line of high tide mark 

 at ordinary tides. Being somewhat conspicuous and 

 unusual, one naturally desired to know how they came 

 there. The action of the water alone is clearly insufficient 

 to account for their presence, and there is no obvious 

 reason why they should have been placed there by man. 

 The only tenable hypothesis is that they were pushed up 

 by the action of floating ice. 



It is a well known fact that in severe winters ice forms 

 along the shore in shallow places to a considerable thick- 

 ness, picking up boulders from the bottom. On the ice 

 breaking up, it drifts through the action of the wind and 

 tide, into the more sheltered bays, where it becomes 

 stranded and eventually deposits its burden of boulders. 

 These in time are pushed up further and further by 

 subsequently formed ice, and ultimately form a ridge at 

 the highest point reached by the drift ice. 



Amongst and on the land side of this row of boulders 

 a blue clayey deposit is accumulating, very similar to that 

 underlying the town and forming the substratum of the 

 peat bog, and the inference is irresistable that the line of 

 boulders seen along the foreshore is merely a repetition 

 of the action which has been going on for a very con- 

 siderable period ; that the ridge is nothing less, in fact, 

 than the commencement or foundation of another terrace. 



Tromso, like Bodo, is built upon a raised beach. It 

 stands on the west side of a narrow channel, through 

 which runs a very strong current. Owing to local causes, 

 the swift portion of the stream is on the side of the strait 

 farthest from the town, whilst near the shore on the town 

 side there is practically no current. The subsoil consists 

 of Blue Clay with a few boulders, not materially diflFerent 

 in appearance from that underlying Bodo, and, as in that 



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