64 AN OUTLINE OF THE 



successful attack. On the mountain tops the striae are 

 weathered off, but the rounded form of many ledges is a 

 significant product of glacial action. The striae trend to 

 the east of south, sometimes deflected to one side or the 

 other by the uneven form of the hills and mountains, 

 but generally persisting rather regularly in their course. 

 These markings are so perfectly matched by those seen 

 on the rocks under the creeping ice streams of Switzer- 

 land, or alongside of the decaying ice sheet of Alaska, 

 that it is unreasonable to doubt that they were produced 

 in the same way. Mount Desert, Maine, New England, all 

 our northern States and Canada beyond them, are thus 

 engraved ; over all of them once lay an ice sheet at least 

 twice as large as that which now swathes Greenland ; and 

 this so little time ago that the ice scorings are still fresh, 

 where protected only by a thin layer of drift. The ice 

 moved outwards towards its margin; and in Maine this 

 was to the south-southeast. We must imagine it advan- 

 cing beyond the present coast line, and terminating in an 

 ice wall in the sea, yielding innumerable icebergs to float 

 for a time southward in the cold 'long-shore current. 



There is a curious transportation of boulders that must 

 be associated with the glacial scoring of the rocks, for it 

 runs in the same direction, and it is of too great an amount 

 to be of postglacial date. It is true that on the young 

 sea cliffs, and at the foot of many of the steeper ledges 

 on the mountain sides, the wasting of the rock progresses 

 rapidly, and blocks have been loosened and moved over 

 short distances, or have fallen down the talus slopes, since 

 the ice sheet retreated ; but so local a distribution of rock 

 fragments will by no means account for the long carriage 

 of the innumerable boulders that are scattered far and 

 wide over the country. Boulders of the easily recognized 

 greenish schists of the western coast of the Island are 

 found removed southward from their parent ledges, in 



