io 6 
ALASKA GLACIERS 
of Alaska, nourishes many glaciers. Of these the Johns 
Hopkins, descending northeastward, has shared the great 
retreat of Glacier Bay; but the Brady, flowing south, and 
the La Perouse and Crillon and their neighbors, flowing 
southwest, have advanced during the same period. 
Close to Disenchantment Bay lies the Malaspina, a pied¬ 
mont glacier fed by alpine glaciers of the St. Elias Range. 
From other slopes of the same range come the principal 
feeders of the Hubbard, the main glacier of Disenchant¬ 
ment Bay. In a century or two the Hubbard has retreated 
five miles up Disenchantment Bay, but the Malaspina is 
bordered in places by a mature forest from which it has 
retired only a short distance, and at one point it has even 
advanced against the forest within a few years. 1 
The general fact appears to be that mere proximity 
does not ensure parallelism of glacial history; on opposite 
sides of a mountain range the sequences of change may 
be not only different but antithetic. 
THEORIES 
In the discussion of the causes of the advance and 
retreat of European glaciers the phenomenon occasioning 
greatest difficulty is the lack of parallelism between the 
variations of different glaciers and different groups of gla¬ 
ciers. The histories of glaciers of the Alps exhibit dis¬ 
parities similar to those of Alaska, with the apparent 
difference that the Alaskan disparities are of larger scale, 
just as the Alaskan glaciation has a larger pattern; and 
the arctic and boreal glaciers of Europe probably exhibit 
equal irregularity, although Rabot, who has recently 
assembled the evidence, finds a number of partial corre¬ 
spondences. 2 
1 I. C. Russell. Amer. Geol., vol. ix, p. 329, 1892. 
2 Les variations de longueur des glaciers dans les regions artiques et boreales. 
Arch, des Sci. Phys. et Nat., 4me periode, vols. 3, 7, 8, 9, Geneva, 1897-1900.*'^ 
