NARRATIVE. 



. 



" We have seen at various points along our routev4arge_aecumulations of 

 loose materials, often in the form of terraces. These loose materials are 

 usually called ' drift,' but it is necessary to distinguish among the vari- 

 ous formations known by this name, the beaches thrown up by the lake 

 upon its present shores, and the ancient terraces above the present level of 

 the water. Nevertheless, the connection between these two kinds of drift is 

 such as to show that the latter also were formed by the lake, but under dif- 

 ferent circumstances from the present beaches. The first question is, whether 

 the lake was anciently higher ; the elevation of the ancient terraces having 

 been the same as now ; or whether the land has been elevated. Either is 

 possible, for we have examples both of elevation and of depression going on 

 in our own day, as upon the eastern coast of Sweden and the western coast 

 of Norway. This question cannot be settled by a simple inspection of the 

 terraces, but only by a comparison of their elevation with the level of the 

 surrounding region. Now the terraces we saw yesterday show a difference 

 of level of over three hundred feet above the present lake beaches. If we 

 add this to the present level of the lake, and suppose it formerly to have 

 stood at the height which they now exhibit, it must have overflowed the 

 whole United States and joined the ocean. But if this were so, we ought 

 to find the remains of marine animals here, which is not the case. It is 

 more probable, therefore, that the land has been elevated. 



" The foundation on which these terraces rest is uniformly rounded and 

 scratched rock. During our whole journey we have nowhere seen serrated 

 peaks ; everywhere the surface is smooth, grooved and scratched in a north 

 and south direction, occasionally diverging east and west. And it is evident 

 that the force that produced these appearances acted from north towards the 

 south, for we generally find the south side of the rocks rough and precipi- 

 tous, showing no abrading action, whereas they are smoothed off towards the 

 north. Now it may be asked whether the loose materials before spoken of 

 were the agents that produced these effects ? I think we may say positively 

 that they were not. We have found the rounding and grooving at the 

 highest point we have visited, that is, over twelve hundred feet above the 

 level of the lake. This is much higher than any of these loose materials 

 are to be found. Moreover we see they are disposed according to the pres- 

 ent form of the lake, and evidently in many instances have been heaped up 

 by a force acting in a direction from south to north, directly contrary to that 

 of the grooving force. It is clear that the formation of the terraces was 

 subsequent. They overlie the grooved and rounded rocks. 



' To ascertain the cause of this latter phenomenon we must find what are 

 its limits. Now we find it occurring universally over the northern portion 



