The next morning, proceeding on our voyage, we plainly observed in the steep banks of the river, the alternate strata of clay and sand, with a thick layer of fertile black mould at the top, and, about eight feet below the surface, a black stratum of bituminous coal, or coal slate, which we were, however, unable to examine closely. On the bank we saw what are called pumice stones, which are pieces of the rock of the Upper Missouri, changed by fire, and brought down by the river; the Indians use this pumice stone to smooth their tanned and hardened skins. At the mouth of the Little Nemahaw River, the Missouri was very shallow. Our vessel having received several violent shocks by striking, and a storm, accompanied by heavy rain, arising, we ran aground, about noon, on a sand bank, and were obliged to put out a boat to take soundings, but the wind, which blew with increasing violence from the open prairie on the south-west, drove us further into the sand bank. Every moment it became more furious; our vessel lay almost on her side, which the people endeavoured to counteract by fastening her with strong cables to the trees lying in the water. After dinner several of our hunters went on shore, but the boat had scarcely returned, when the storm suddenly increased to such a degree that the vessel appeared to be in imminent peril. One of our chimneys was thrown down, and the foredeck was considered in danger; the large coops, which contained a number of fowls, were blown overboard, and nearly all of them drowned. As they got upon the sand banks they were afterwards taken up, with other things which we had been obliged to throw overboard; our cables had, happily, held fast, and, as the wind abated a little, Captain Bennett hoped to lay the vessel close to the bank, which was twenty feet high, where it would be safe [pg. 126] but the storm again arose, and we got deeper and deeper into the sands. Some of our hunters and Mr. Bodmer appeared on the bank, and wanted to be taken on board, but the boat could not be sent, and they were obliged to seek shelter from the storm in the neighbouring forests. Mr. Mc Kenzie, and other persons acquainted with the Missouri, assured us they had never encountered so violent a storm in these parts. After four o'clock, however, the wind abated, and the boat was dispatched to pick up the articles we had lost.