402 LAKE SUPERIOR. 



SO many otherwise intelligent geologists, to perceive the facts as they 

 are, whenever they bear upon the question of drift, I cannot but 

 repeat, what I have already mentioned more than once, but what I 

 have observed again here over a tract of some fifteen hundred 

 miles, that the rocks are everywhere smoothed, rounded, grooved 

 and furrowed in a uniform direction. The heterogeneous materials 

 of which the rocks consist are cut to one continuous uniform level, 

 showing plainly that no diflference in the polish and abrasion can be 

 attributed to the greater or less resistance on the part of the rocks, 

 but that a continuous rasp cut down everything, adapting itself, how- 

 ever, to the general undulations of the country, but nevertheless 

 showing, in this close adaptation, a most remarkable continuity in 

 its action. 



That the power which produced these phenomena moved in the 

 main from north to south, is distinctly shown by the form of the hills, 

 which present abrupt slopes, rough and sharp corners towards the 

 south, while they are all smoothed off towards the north. 



Indeed, here, as in Norway and Sweden, there is on all the hills a 

 lee-side and a strike-side. As has been observed in Norway and 

 Sweden, the polishing is very perfect in many places, sometimes 

 strictly as brilliant as a polished metallic surface, and everywhere 

 these surfaces are more or less scratched and furrowed, and both 

 scratches and furrows are rectilinear, crossing each other under 

 various angles : however, never varying many points of the compass 

 on the same spot, but in general showing that where there are 

 deviations from the most prominent direction, they are influenced by 

 the undulations of the soil. It has been said, that the main direction 

 of these striae was from north-west to south-east, but I have found it 

 as often strictly from north to south, or even from north-east to 

 south-west ; and if we are to express a general result, we should say 

 that the direction, assigned by all our observations to the various 

 scratches, tends to show that they have been formed under the influ- 

 ence of a movement from north to south, varying more or less to the 

 east and west, according to local influences in the undulations of the 

 soil. It is, indeed, a very important fact, that scratches which seem 

 to have been produced at no great intervals from each other, are not 

 absolutely parallel, but may diverge for ten, fifteen, or more degrees. 



