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laiometres glacial epoch, and upon the retreat of the Vashon 

 glaciers the uneroded portions of the inter-glacial 

 deposits were left as long, nearly straight, 

 esker-like ridges, their axes having a general 

 strike of S. 25 E. Since the retreat of the 

 Vashon glaciers and the comparatively recent 

 uplift these deposits have been rapidly retro- 

 graded into the steep cliffs about 100 feet 

 (30 m.) high, which are seen on both James 

 and Sidney islands. The retrograded material 

 has been carried northward by the prevailing 

 shore currents, building the long spits and 

 beaches that are seen extending north from 

 Sidney island. As the steamer leaves Sidney 

 channel, the mature southern shore of James 

 island is seen. Here the inter-glacial deposits 

 have been retrograded, presumably for over 

 a mile, resulting in a straight shore line with 

 nearly vertical cliffs, which in the central 

 portion is over 200 feet (60 m.) high. An 

 idea of the rapidity of the retrogression of this 

 shore is shown by a wire fence, which in 1907 

 was built to the edge of the cliff and which 

 in 1 9 10 had been undermined for 24 feet (7-3 m.) 

 apparently not all at once but gradually, as 

 that part of the cliff was retrograded uniformly 

 with the rest. It is improbable however, 

 that the entire shore-line is being retrograded 

 at the rate of 6 feet (i-8 m.) a year, but the 

 rate is doubtless more than one foot (0-3 m.). 

 As a result of this retrogression a good section 

 of the till-covered deposits is obtained, affording 

 a proof of their inter-glacial origin, and of the 

 fact that the inter-glacial drift ridges are erosion 

 remnants of once more extensive deposits and 

 are not constructional forms, since the outline 

 of the present surface of the ridge cuts sharply 

 across the bedding of the deposits. The 

 southern shore of Sidney island is in marked 

 contrast to that of James island, for on 

 Sidney island the drift which doubtless originally 

 covered the hard rocks, has been largely removed 

 and a very irregular shore-line, still in an early 

 stage, is the result. This has been called, 



