FORMER EXTENT OF GLAOIATIOX. 210 



a famous ne8tin,G:-i)lace of the eider duck, which finds it suitahle to its 

 purpose because of this raggedness of surface. Tlie isUind bears no sign 

 of glacial abrasion. It stands at the mouth of Wolstenholme sound, on 

 the west coast, in about latitude 76° 50'. In other words, it is just off the 

 border of one of tlie broadest stretches of Greenland's ice-field. Thirty 

 or forty miles distant to the west-northwest lie the Gary islands, which 

 are formed of almost identical rock. They are very notably abraded by 

 glacial action coming from the north. Stria? are still preserved upon 

 them at heights of 500 feet above the sea. There also occur U})on them 

 erratics of limestone, sandstone, shale and quartzite wholly unlike any- 

 thing that occurs in the islands themselves. So far as I know, no rock of 

 similar kind occurs in Greenland to the eastward. These erratics appear 

 to have come from the region beyond Smiths sound to the north, either 

 from Grinnell land or from the northwestern coast of Greenland — more 

 likely tlie former than the latter. It appears, therefore, that while a very 

 notable southerly movement from the far north took place down the 

 valley and reached at least to the Gary islands, there was no correspond- 

 ing movement from the east. (Figures 15 and 16, plate 10.) 



At the very first glimpse of the coastal mountains of southern Green- 

 land I was impressed by tlieir i)ronounced angularity and the absence, 

 unless it were in the lower valleys, of any notable signs of the horizontal 

 rasping whicli must have resulted had the inland ice ever pushed across 

 them into Baftins bay. Subsequently I saw approximately a thousand 

 miles of coastline, and an effort was made to discriminate the portions 

 once overridden by ice from those which had not been. Tracts of angular, 

 unsubdued topography were found alternating with tracts of rounded, 

 flowing contours. About one-half of the coast seemed to belong to each 

 type. The inference was drawn that the ice formerly so extended itself 

 as to reach the present coast for about half of its extent, while in the re- 

 maining portion the ice fell short. 



Gombining this topographic evidence with the specific data furnished 

 by a comparison of Dalrymple island with the Gary islands 'and with 

 the still more stubborn facts off'ercd by the driftless area of Bowdoin bay, 

 the inference seems unavoidable that the ice of Greenland, on its western 

 side, at least, has never advanced very greatly ])eyond its present ])ordcr 

 in recent geologic times. This carries with it the dismissal of the hy- 

 pothesis that the glaciation of our mainland had its source in Greenland. 



Formp:r Altitude of CrREEXLAxn. 



There is no ground to question the former elevation of Greenland. Its 

 plateaus, like its valleys, indicate this ; but glacialists are especially con- 

 cerned to know whether the former elevation of CJreenland was coincident 



