The survey of these productions of human industry, these monuments without inscription, commemorating the existence of a people once numerous and powerful, but no longer known or remembered, never fails, though often repeated, to produce an impression of sadness. As we stand upon these {60} mouldering piles, many of them now nearly obliterated, we cannot but compare their aspect of decay with the freshness of the wide field of nature, which we see reviving around us; their insignificance, with the majestic and imperishable features of the landscape. We feel the insignificance and the want of permanence in every thing human; we are reminded of what has been so often said of the pyramids of Egypt, and may with equal propriety be applied to all the works of men, "these monuments must perish, but the grass that grows between their disjointed fragments shall be renewed from year to year."[086] June 21st. After completing our arrangements at St. Louis, we left that place at noon, and at 10 o'clock on the following day, entered the mouth of the Missouri. From St. Louis upward to the Missouri, the water of the Mississippi, for a part of the year, is observed to be clear and of a greenish colour on the Illinois side, while it is turbid and yellow along the western bank. But at the time of our ascent every part of the Mississippi appeared equally turbid, its waters soon becoming blended with the heavy flood of the Missouri. The Missouri being now swollen by the spring floods, which had subsided in the Mississippi, entered that river with such impetuosity, as apparently to displace almost the whole body of the waters in its channel. We had occasion to observe that the water of the Missouri passes under that of the Mississippi, rising and becoming mingled with it on the opposite shore, so that a portion of the clear, green waters of the latter river run for some distance in the middle of the channel, and along the surface of the Missouri waters, rendered perhaps specifically heavier by the great quantities of earthy matter mingled with them. The waters of the Missouri are so charged with mud and sand as to be absolutely opake, and of a clay {61} colour; while those of the Mississippi being comparatively clear, and having a somewhat olivaceous tint, afford an opportunity of tracing their respective courses, after their junction in the same channel. At some stages of water they run side by side, and in a great measure unmingled as far as Herculaneum, forty-eight miles below their confluence. We had the pleasure to find, notwithstanding the furnace was supplied with wood of an indifferent quality, that the force of our steam-engine was sufficient to propel the boat against the current of the Missouri, without recourse to the aid of the _cordelle_,[087] which we had expected to find necessary.