chase away the vapors, I am not able to say. I have certainly not been misled by fancy. We are now two thousand six hundred miles from the ocean; as the Missouri, some distance above the Mandan villages, flows from the west, it is probable that its descent is not so great as below: so that allowing one foot per mile, we can be little short of three thousand feet above the ocean. It is said, that on the high plains of Switzerland, between the mountains, the sky is observed to possess a deeper azure; the same cause may produce the like effect on these plains. Here, we are elevated above the fogs and mists of lakes and rivers, and the sun does not transmit his rays through the white medium of clouds. The light dress of vegetation, with which these plains are clothed, may likewise be considered. Where the vegetation is luxuriant, dense vapours arise during the night; and noxious gases are produced, which floating into the atmosphere, lessen its brightness {177} as well as its purity. But, whatever may be the cause of the superior beauty of the azure in the heavenly vault, I experienced a peculiar pleasure in contemplating it. The sun beams seemed to have less fierceness than I had ever experienced, in fact, I could almost fancy myself in the midst of enchanted scenes.
Continued the greater part of the day with the cordelle, along the prairie. The country on either side, of a very pleasant appearance, with a number of wooded points.
Tuesday 23d [i. e., 25th]. Hoisted sail this morning with a fine breeze. At ten o'clock passed the remains of a Mandan village, and at some distance espied a great number of Indians on shore, moving down the river. We soon discovered them to be Mandans. They sometimes go on hunting parties by whole villages, as was the case at present. They appeared to be about five hundred in number, some on horseback, the greater part on foot. A numerous
