the Appalachian coal-field may be seen in the western part of the section at p. 92. Vol. I.* At the edge of the left bank of the Monongahela, we collected shells of many species of freshwater muscles (Unio), and were much interested in finding them all different from those which we had previously met with in the Connecticut, Delaware, and other eastern rivers. We had now in fact entered an entirely new zoological province, so far as conchology was concerned. May 15. 1842.-We embarked at Brownsville for Pittsburg in a long narrow steamer, which drew only eighteen inches water, and had a single paddle behind like the overshot wheel of a mill. It threw up a shower of spray like a fountain, which had a picturesque effect. The iron-works of the machinery and the furnace were all exposed to view, and the engineers were on deck in a place cooled by the free circulation of air. The wooded hills rise to the height of from 300 to 450 feet above the river between Brownsville and Pittsburg. (See Pl. VI.) The latter place is situated at the junction of the Alleghany and Monongahela rivers, which after their union form the Ohio. It is a most flourishing town, and we counted twentytwo large steam-boats anchored off the wharfs. See also Description of Map. From the summit of the hill, 460 feet high, on the left bank of the Monongahela, we had a fine view of Pittsburg, partially concealed by the smoke of its numerous factories. A great many fine bridges span the two broad rivers above their junction. In the same hill, I saw a fine section of the horizontal coal-measures. Far below the principal seam, and near the level of the river, there is a bed of coal a few inches thick, resting on clay. Upon this coal are layers of shale and limestone, in which I found the same Bellerophon allied to, or identical with, B. Uri, and the same Leptana sarcinulata, Spirifer, allied to S. Urü, and other shells, which occur at Frostburg, together with Encrinus, and a small coral. The steam-boats on the Ohio cannot be depended upon for punctual departure at the appointed hour, like those of the Hudson or Delaware. I therefore took places in a coach for Wheeling, and crossed a low and nearly level country, where I was struck with the absence of drift and boulders, so common in the north. The carboniferous strata were exposed on the banks of every small streamlet, and not concealed by any superficial covering. On reaching one of those innumerable towns to which, as if for the sake of confusion, the name of Washington has been given, I received the agreeable intelligence that, instead of travelling to Wheeling before sunset, I must wait till another mail came up in the middle of the night. I was very indignant at this breach of promise, but was soon appeased by the good-natured landlord and postmaster, who addressed me by the conciliatory appellation of "Major," and assured me that the new post-office regulation was as inconvenient to him as it could possibly be to us. The next day we embarked at Wheeling on the Ohio for Marietta. I had been requested by my geological friends, when at Philadelphia, to make inquiries respecting some Indian corn said to have been found fossil at some depth in a stratified deposit near Fish Creek, a tributary of the Ohio, and presumed to be of high antiquity. A proprietor who had resided twenty-six years near the spot assured me that the corn occurred in an island in the river at the depth of no more than two feet below the surface of the alluvial soil. It consisted of parched corn, such as the Indians often buried when alarmed, and in the present year the Ohio had risen so high as to inundate the very spot, and throw down several fresh layers of mud upon the site of the corn. Five miles below Wheeling, on the left bank of the Ohio, is a terrace of stratified sand and gravel, having its surface about seventy-five feet above the Ohio. On this terrace is seen a large Indian mound. On our arriving at Marietta, I learnt from Dr. Hildreth that skeletons had been found in it at various depths, together with pipe-heads and other ornaments. Their workmanship implies a more advanced state of the arts than that attained by the rude Indians who inhabited this fertile valley when it was first discovered by the white man. There are many other similar mounds in the valleys of the Ohio and its tributaries, but no tradition concerning their origin. One of these, near Marietta, in which human bones were dug up, must be more than eight centuries old, for Dr. Hildreth counted eight hundred rings of annual growth in a tree which grew upon it. But, however high may be the historical antiquity of the mounds, they stand on alluvial terraces which are evidently of a very modern geological date. In America, as in Europe, the oldest monuments of human labour are as things of yesterday in comparison with the effects of physical causes which were in operation after the existing continents had acquired the leading features of hill and valley, river and lake, which now belong to them. Dr. Locke of Cincinnati has shown that one of the earthworks, enclosing about one hundred acres on the great Miami, although nearly entire, has been overflowed in a few places, and partially obliterated. He infers from this and other facts, that these mounds ex tending to high-water mark, and liable to be occasionally submerged, were constructed when the streams had already reached their present levels, or, in other words, their channels have not been deepened in the last 1000 or 2000 years. * The arguments for assigning a very remote period to the Indian antiquities above alluded to, have been stated with great force and clearness by General Harrison, late President of the United States, who was practically versed in woodcraft, and all that relates to the clearing of new lands. In his essay on the aborigines of the Ohio valley †, he states, that some of these earthworks are not mere mounds, but extensive lines of embankment, varying from a few feet to ninety feet in altitude, and enclosing areas of from one to several hundred acres. "Their sites," he says, " present precisely the same appearance as the circumjacent forest. You find on them all that beautiful variety of trees which give such unrivalled richness to our forests. This is particularly the case on the fifteen acres included within the walls of the work at the mouth of the great Miami, and the relative proportions of the different kinds of timber are about the same." He then goes on to observe that if you cut down * Trans. of Amer. Geologists and Naturalists, p. 232. |