Tlie buried Fared. 39 



sides of the gullies would' have been planed down and these 

 features obliterated. We can, however, equally well look upon 

 it as evidence that the ice did not cover them' for a very long 

 period. 



The trees of the buried forest (see plate 12) must have grown 

 when the glacier was smaller than it is now. The sand and 

 gravel Avas then carried in among them until they were com- 

 pletely buried, after which the glacier pressed forward and moved 

 over the sand. Now, these trees are most probably of the same 

 species as the spruce now growing in the neighborhood of Juneau 

 (see supplement iii), and therefore it seems we should reckon the 

 time elapsed since they were alive in centuries rather than in 

 thousands of 3^ears. Another evidence lies in the logs found 

 on moraines and on mountain slopes. We found them in the 

 moraine in front of White glacier, on the moraine issuing from the 

 eastern side of the first northern tributary, on the eastern shore of 

 Muir inlet south of the stream, in the gully east of camp, and in 

 gullies on the northeastern side of G ; in fact, over most of the 

 region about the southeastern part of the glacier. In these gullies 

 they seemed much covered with debris, coarse and fine, which 

 has apparently protected them from being ground up by the ice. 

 Now, it hardly seems possible that this wood should not all have 

 l)een carried away long ago if its origin had not been compara- 

 tively recent. 



Before the advance the glacier must have been very much 

 smaller than at present to allow the region about the first north- 

 ern tributary, which is now bare and bleak, to support trees ; 

 and it must have remained smaller for several hundred years to 

 allow the trees of the buried forest, some of which are two feet 

 or more in diameter, to attain their size. A piece of one of these 

 trees shows 22 rings in a thickness of one-third of an inch, which 

 would give a rate of growth of one inch in diameter in 33 years. 

 It seems probable that this very slow rate does not apply to the 

 whole life of the tree, but only to its later years. The wood was 

 from the outside. 



Although the evidences indicating a short duration for the last 

 advance of the glacier is not decisive, still this supposition seems 

 to be in harmony with all the facts. Probably the principal 

 objection that can be urged against it is that the changes are 

 much more rapid than any we are familiar with. Let me, how- 

 ever, call attention to certain historical facts collected by Venetz 

 and Agassiz, which show that during the middle ages, from per- 



