drawing more than from 12 to 18 inches water, could pass this rapid without lightening, and it appears to form one of the first obstacles of consequence in the navigation of the Arkansa.[190]
The variety of trees which commonly form the North American forest, here begin very sensibly to {170} diminish. We now scarcely see any other than the smooth-barked cottonwood, the elm, box-elder (Acer Negundo), curled maple (Acer dasycarpon), and ash, all of them reduced in stature. From hence the forest begins to disappear before the pervading plain. To-day we were favoured with a fine south-east breeze, and sailed along with rapidity. Early in the afternoon we passed Bougie's island, near to which, and in two other places, the hills, of about 300 feet elevation, approach the river; the rocks being still a slaty sandstone. Elk and deer now appeared common on the sand beaches, being obliged to come to the river for water, as the springs in the prairies are at this season nearly all dried up. We continued to pass several rapids, with the water curling over beds of gravel. According to the common estimate, we proceeded to-day 45 miles, and in the evening were only two leagues from our destination.
14th.] This morning we passed a low ledge of rocks on our left, apparently the usual dark-coloured slaty sandstone, and which has received the name of the Charbonniere,[191] from the appearances of coal which it exhibits. On this side, the prairie approaches the immediate bank of the river, and presents a very unusual open prospect. We again passed three or four difficult rapids, within the
