BOUNDARY OF THE GLACIATED ABE A. 189 



glacial ice adjusts itself to the local topography, is, as already 

 stated, of a most explicit character.* In addition to the evi- 

 dence already mentioned, we may add that numerous islands 

 project from the surface of the Muir Glacier, as from the 

 waters of an archipelago, and that the summits of these bear 

 every mark of having been freshly uncovered by the decreas- 

 ing volume of ice. Also that below the mouth of the gla- 

 cier numerous islands in the bay present exactly the same ap- 

 pearance, except that they now project from water instead of 

 ice. Their recent glaciation is indicated by every character- 

 istic sign. Willoughby Island, about the middle of the bay, 

 is as much as a thousand feet above the water. Were the ice 

 to retreat a few miles farther back from its present front, it 

 would doubtless uncover an extension of the bay, with numer- 

 ous islands similar to those now dotting its surface south of 

 the glacier. Fresh glacial debris lingers on the flanks of the 

 mountains on either side of the inlet, to a height of 2,000 

 feet. The fact is also worth repeating and emphasizing that 

 at 3,700 feet above tide striae were observed, on the east side 

 of Muir Inlet, not pointing down the mountain, as might be 

 expected, but parallel with the axis of the bay, showing, be- 

 yond controversy, that the present glacier is but a remnant 

 of an earlier ice-movement, similar in character and direction 

 to the present, but of vastly greater dimensions, and which 

 extended until it filled the whole bay to its mouth in Cross 

 Sound, a distance of twenty-five miles. At Sitka, also, the 

 rocks of the harbor are all freshly striated — the direction of 

 the striae being toward the west — that is, toward the open sea. 

 Glaciers still linger in the mountains at the head of the bay 

 to the east of Sitka. 



The absence of glacial phenomena north of the range of 

 mountains, which forms the southern boundary of Alaska, and 

 over the adjacent plains of Northern Siberia, completely 

 disproves the once current theory that the glacial period 

 was characterized by a vast ice-cap extending in all directions 



*See above, p. 56 et seq. 



