De Geer.] 
474 
[May 18, 
The gradient of the deformed geoid surface wus evidently 
steepest on the Atlantic side of the continent, where the 
slope of the ice-sheet must also have been greatest ; it is here 
generally 1 : 1,400, with the exception of the St. Lawrence valley, 
where its direction is oblique to its general trend against the 
Atlantic and its amount is not larger than about 1 : 4,900. 
The steep gradient will probably be found also at the coast of 
Labrador, which in many respects is analogous with the high, 
fiord-cut coast of Norway in Scandinavia. In the interior of the 
American continent, where the ice spread out over a large area, 
the isobases are far more distant and show a smaller gradient just 
as in Scandinavia. Thus the mean gradient from Georgian Bay 
toward the southwest to the limit of the area seems about 1 : 
3,400, being much steeper at the border of the azoic region and 
smaller at the outside. 
The connection between the subsidence and the geological 
structure of the earth’s crust is perhaps not quite so striking as 
in Scandinavia. Still it seems probable that the Canadian 
azoic or Archaean region has changed its level more than the 
surrounding tracts, though this is not yet sufficiently proved in 
regard to Hudson Bay. The general conformity between the 
ice covering and the old azoic plateau makes it difficult in the 
present state of our knowledge in many cases to discern between 
the influence of these two circumstances. Thus it may be re- 
marked that the above mentioned convexity of the isobases around 
the Atlantic peninsula may also have some connection with the 
Atlantic mountain ranges, and that the most uplifted part lies near 
the Adirondacks, consequently at quite a distance west of the 
iceshed at Quebec. The fact that Newfoundland, which at least 
during the last extension of the glaciers may have been only 
locally glaciated, also shared in the submergence may in some 
degree be accounted for by its geological structure. 
All the above statements concerning the late glacial upheaval 
are based upon the height to which the marine deposits are up- 
lifted, but as we generally cannot tell whether this rising of the 
land has been continuous or partly counteracted bv subsidence, 
it would be more correct to speak of it as the final result of the 
changes of level since the maximum of the late glacial submer- 
gence. 
Along certain parts of the Atlantic coast many facts were ob- 
