"As the canoes were heavily laden, all the men not employed in working them walked on shore. The navigation is now very laborious. The river is deep, but with little current; the low grounds are very narrow; the cliffs are steep, and hang over the river so much, that, in places, we could not pass them, but were obliged to cross and recross from one side of the river to the other in order to make our way." FOOTNOTE: [1] Dimensions of Niagara Falls,--American, 960 feet wide, 162 feet high; English, 700 feet wide, 150 feet high. CHAPTER VII. JOURNEY CONTINUED. July 4.--Since our arrival at the falls, we have repeatedly heard a strange noise coming from the mountains, in a direction a little to the north of west. It is heard at different periods of the day and night, sometimes when the air is perfectly still and without a cloud; and consists of one stroke only, or of five or six discharges in quick succession. It is loud, and resembles precisely the sound of a six-pound piece of ordnance, at the distance of three miles. The Minnetarees frequently mentioned this noise, like thunder, which they said the mountains made; but we had paid no attention to them, believing it to be some superstition, or else a falsehood. The watermen also of the party say that the Pawnees and Ricaras give the same account of a noise heard in the Black Mountains, to the westward of them. The solution of the mystery, given by the philosophy of the watermen, is, that it is occasioned by the bursting of the rich mines of silver confined within the bosom of the mountain.[2] "An elk and a beaver are all that were killed to-day: the buffaloes seem to have withdrawn from our neighborhood. We contrived, however, to spread a comfortable table in honor of the day; and in the evening gave the men a drink of spirits, which was the last of our stock." VEGETATION. "July 15.--We find the prickly-pear--one of the greatest beauties, as well as one of the greatest inconveniences, of the plains--now in full bloom. The sunflower too, a plant common to every part of the Missouri, is here very abundant, and in bloom. The Indians of the Missouri, and more especially those who do not cultivate maize, make great use of this plant for bread, and in thickening their soup. They first parch, and then pound it between two stones until it is reduced to a fine meal. Sometimes they add a portion of water, and drink it thus diluted; at other times they add a sufficient proportion of marmow-fat to reduce it to the consistency of common dough, and eat it in that manner. This last composition we preferred to the rest, and thought it at that time very palatable. "There are also great quantities of red, purple, yellow, and black currants. The currants are very pleasant to the taste, and much preferable to those of our gardens. The fruit is not so acid, and has a more agreeable flavor." THE BIG-HORNED OR MOUNTAIN RAM.