246 THE FOREST LANDS OF FINLAND. 



Both theories attribute them to the action of ice. In one 

 of these, advanced and expounded in a volume entitled 

 Frost and Fire, by Mr J. F. Campbell, they are attri- 

 buted to the friction of icebergs and icefloes, drifting from 

 the north on ocean currents. In the other, advanced, 

 maintained, and illustrated by Agassiz, Ramsay, Lyell, 

 Chambers, Jamieson, and Geikie, they are attributed to 

 the grating action of glaciers, or land ice, formed where 

 they are seen, or at a somewhat higher level, and con- 

 tinuously descending in a state of flux to a lower level. 



By some of the geologists whom I have cited it is held 

 that in what is known as the glacial period Scotland must 

 have been covered with one wide-spread sheet of ice and 

 snow of great thickness, as at the present day is Northern 

 Greenland, where there may be seen an interminable glacier, 

 extending league upon league, broken only by some black 

 hill top or mountain peak that rises as an island above the 

 sea of ice. But there this vast sheet is ever, even while 

 being replenished by fresh falls of snow, slowly and 

 persistently flowing, or rather creeping, down to the sea, 

 covering the face of the country, filling up the valleys, 

 mounting over the hills, and pressing with constant resist- 

 less force upon all the rocks over which it advances ; and 

 blocks of stone, either loosened from the mountain by 

 frost, or torn off by the moving glacier, are jammed in in 

 the rear, and pressed along the rocky bed or sides of the 

 valley ; and the stones, mud, gravel, and sand thus borne 

 along act like files scratching and scoring the hardest 

 rocks, and being themselves scratched by the same process. 

 As it is now in North Greenland so must it have been 

 during the glacial period in Scotland. There we find the 

 rounded, filed down projections on the mountain top and 

 on the mountain sides, and the parallel striae. So must it 

 have been at the same period, and on to a later time, in 

 .Norway ; and thus many numerous phenomena presented 

 by the mountains and the rocks there be satisfactorily 

 accounted for; and to the same operation may be attri- 



