NARRATIVE OF THE EXPEDITION. 51 



Two soldiers wlio were sickly, Averc here returned, and five able- 

 bodied men received to supply their places, thus increasing the 

 aggregate of the party to forty persons.* 



The banks of the River St. Clair are wholly alluvial or diluvial. 

 There is not a particle of rock in place. One idea presses itself 

 prominently to notice, in reflecting on the formation of the country. 

 It is the vast quantum of clay, mixed drift, and boulders, which 

 have evidently been propelled, by ancient forces, down these 

 straits, and afterwards arranged themselves according to affinities, 

 or gravitation. At the precipitous banks between the inlet of 

 Black River and Fort Gratiot, this action has been so clearly 

 within the erratic block period of De la Buck, that it has imbedded 

 prostrate forest-trees, and even freshwater shells, beneath the 

 heavy stratum of sand, resting immediately upon the fundamental 

 clay beds, upon which the city of Detroit, and indeed the alluvions 

 of the entire straits rest.f We again encountered at this place, 

 blocks of the primitive or crystalline boulders, which were first 

 seen at Grosse Point. There are some traces of iron sand along 

 the shore of this river, the only mineral body, indeed, which has 

 thus rewarded my examinations. 



We left our encampment, at Fort Gratiot, at eight o'clock next 

 morning. A strong and deep rapid is immediately encountered, 

 up which, however, vessels having a good wind find no difficulty 

 in making their way. On surmounting this, we found ourselves 

 on the level of Lake Huron. The lake here bursts upon the 

 view in one of those magnificent landscapes which are peculiar 

 to this region. Nature has everywhere operated on the grandest 

 scale. Wide ocean expanses and long lines of shore spread 

 before the eye, which gazes admiringly on the broad and often 

 brilliant horizon, and then turns, for something to rest on, alono- 

 the shore. Long ridges of gravel, sand, and boulders, meet it 

 here. Beyond and above this storm-battered beach, are fringes 

 of woods, or banks of clay. The monotony of travelling by un- 

 varied scenes is relieved by an occasional song of the boatmen, 



* To cover any arrangements of this kind, general orders had been issued by 

 Gen. Macomjp, to the commandants of the western posts. 



f In the artesian borings for water, undertaken by Mr. Lucius Lyon, at Detroit, 

 in 1833, these clay beds were found to be one hundred and fifteen feet deep. — Vide 

 Historical and Scientific Sketches of Michigan, p. 177. 



