252 THE FOREST LANDS OF FINLAND. 



the line of descent of the Highland glen down which in 

 pre-Adamic times poured the glacier which hollowed out 

 the basin. The confining sides of a valley once formed 

 would elongate the furrow or depression thus created in a 

 direct rather than a cross direction. But alternate eleva- 

 tions and depressions, and thus a succession of lakes in 

 the thalweg of the glacier, may have been thus produced. 

 The rasping of the ice, charged with fragments of stone, 

 and gravel, and sand, would occasion striae and markings 

 on the rocks, and by the direction of these may be traced 

 the direction of the movement, while variations in the 

 direction of these can be accounted for. 



The striae produced by glaciers are generally apparently 

 parallel and straight The normal aerial currents, popu- 

 larly known as the ' trade winds,' produced by well 

 known causes, follow a curved direction, throwing off 

 eddies both upward and horizontal. Similar currents and 

 eddies have been observed in the ocean. Like eddies may 

 be seen in the river, and even in the cup of tea, produced 

 by upward currents from the dissolving sugar ; and striae 

 may be seen following a curve more or less expanding, and 

 more or less contracting, which variation in their direction 

 may have been similarly produced. 



Besides the lakes and successions of lakes with which 

 we meet in Finland, there are such moraines as are men- 

 tioned in my quotation from Dr Ignatius. 



One of the results of the flux of a glacier is the formation 

 of a deposit of stones at the extreme edge of it ; stones 

 which have been borne along on its surface, or, it may be, 

 in some cases a little way beneath this by the slow massive 

 advance of the body of ice, on reaching the extremity of it 

 where it is slowly melting away, though continuously 

 replaced, like the lower fringe of the so-called * Devil's 

 Table-Cloth ' on Table Mountain, which has been spoken 

 of, there drop and accumulate. We have had several 

 elevated ranges of great magnitude characterised as such : 

 the Salpausselka, and another further to the north. 



