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, along 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 unvaried scenes is relieved by an occasional song of the boatmen, or an occasional landing--by changes of forest-trees--of the wind, or flights of the gull, duck, plover, and other birds; but the traveller, is apt, before evening comes, to fancy himself very much in the position of a piece of merchandise which is transported from place to place. Glad were we when night approached, and the order to encamp was heard. It was estimated we had advanced thirty-five miles. On passing along the Huron coast about fifteen miles, a bank of dark clay is encountered, which has an elevation of thirty or forty feet, and extends six or eight miles. We soon after came to the White Rock--an enormous detached mass, or boulder of transition,[16] or semi-crystalline limestone. It is a noted landmark for _voyageurs_ and travellers, and an equally celebrated place of offerings by the Indians. I requested to be landed on it, and detached some specimens. Geologically, it is a member of the erratic block group, and we must look for its parent bed at a more westerly point. There is no formation of limestone, in this quarter, to which it can be referred. It bears marks of attrition, which shows that it has been rubbed against other hard bodies; and if transported down the lake on ice, it is necessary to consider these marks as pre-existing at the era of its removal. [16] This term has disappeared from the geological vocabulary under the researches of Sir Roderick J. Murchison, Mr. Lyell, and other distinguished generalizers.