somewhat narrower, though neither hills nor cliffs approach the bank. This morning, however, we again observed a horizontal ledge of the grauwacke slate. About four miles above the Canadian, we passed the river Illinois,[189] on the right, a considerable stream of clear water, as are all the other rivers flowing into the Arkansa from the north. A few miles from its mouth, its banks present salt springs similar to those of Grand river, and scarcely less productive; indeed, most of the streams on this side the Arkansa are said to afford springs of salt water which might be wrought with profit. On the south side, the salines commencing about the Canadian, occur in the red clay formation, forming as it were a belt which extends to the third Red fork, or saline rivulet of the Arkansa. The salines on the north, appear rather in connection with the coal formation, at least, they do not belong to the same series as those on the south side of the river.
This afternoon, two of the hunters went out and brought in the most part of the meat of a fat bison, whose track they had followed from the bar.
About four miles above the Illinois, we came to a cascade of two or three feet perpendicular fall. In endeavouring to pass it, our boat grounded upon the rocks, and we spent several hours in the fruitless attempt to pass them, but had at last to fall back, and attempt it again in the morning, which we then (on the 13th) effected by the assistance of the wind without much difficulty, by passing further into the shute. At this season, in which the water is far from being at its lowest ebb, no boats
