Correspondence — Mr. G. Linnarsson. 95 



Tornebolim, James Geikie, and other observers. In sucli cases it is 

 quite impossible to admit floating-ice as the working cause, and 

 ■we must recur to glacier-ice. It is not here the place to discuss 

 the physical conditions which produce these effects ; it is enough to 

 point to the fact. 



If it is thus evident that the phenomena in question can have been 

 effected by the action of a continental ice-sheet, it remains for us to 

 show that they cannot have been effected in the manner advocated 

 by Professor Milne. 



That the Till — which in no part of Sweden is more developed than 

 in the south — cannot have been formed by the action of floating- 

 ice, is evident to any one who has seen some sections of that deposit, 

 with its striated blocks, heaped confusedly together in the tough 

 tenacious mud. We have, in Sweden, in many places, gravel-beds 

 which have evidently been deposited by shore action, but they have 

 quite another aspect ; the gravel is more or less stratified, the stones 

 are rounded, not scratched, and the fine mud is washed off, so that 

 this gravel is far less coherent than the Till. The scratches in the 

 rocks are usually best marked below the Till, and it is therefore 

 probable that the result is from the same cause. That they cannot 

 result from the action of coast-ice is evident from many reasons. 

 Firstly, it is impossible to conceive how the scratches could have 

 such a constant direction in large regions, if they were produced by 

 coast-ice. Professor Milne himself correctly remarks, that the 

 directions of the scratches "point seawards, or else to the lowest 

 land," but, strangely enough, he adds that this circumstance is 

 rather more favourable for his own views. Everybody, however, 

 knows that glacier-ice moves downwards, and therefore it is natural 

 that the scratches, on the whole, have that direction, if produced by 

 glacier-ice. On the contrary, if produced by coast-ice, their direc- 

 tion is independent of the slope of the land, and must vary according 

 to the currents and the winds. Further, in the isles along the Baltic 

 coasts of Sweden, the striation and polishing is most marked on 

 their landward face, from whence the glacier must have come, 

 whereas their outer sides ought to have been more polished and 

 scratched, if the coast-ice had produced these effects. 



It cannot be denied that, as Professor Milne says, the abrading 

 action of coast-ice is an undoubted fact, but it must be remarked, 

 that in the coasts of Sweden and Finland, and especially near the 

 route followed by him, this action is excessively small. The rocks 

 are there so hard and compact, and the force of the waves so small, 

 that their action on the rock-surface is hardly perceptible. A rock 

 may be exposed there for hundreds of years to the waves, without 

 the finest scratches being abraded. Professor Milne thinks that, to 

 be preserved, they " must always have remained above sea-level, or 

 else have been shielded by some protective covering during both 

 subsidence and elevation," but it is so far from this being the case 

 that, on the contrary, the scratches are much better preserved 

 beneath the water than in the open air a few feet above it. In the 

 open air the scratches usually become obliterated in a few years by 



