Page:The American Cyclopædia (1879) Volume XII.djvu/605

 OHIO 591 no striking features, its surface is pleasingly diversified. The general aspect is that of a plateau whose average elevation is 300 to 500 ft. above Lake Erie, which lies 565 ft. above the sea. The highest point in the state is in Logan co., 1,540 ft., and the lowest the shore of the Ohio near Cincinnati, 433 ft. above the sea. The numerous draining streams have deeply excavated and eroded this plateau, giv- ing the surface an alternation of hills and valleys and a general rolling character. The most prominent feature in the topography is the great divide separating the drainage of Lake Erie from that of the Ohio. This passes diagonally across the state from Trumbull co. in the northeast to Mercer and Darke cos. in the west, with an average altitude of about 600 ft. above Lake Erie. From the summit of the watershed the surface slopes gradually north- ward to the lake and southward to the Ohio, and is more or less eroded by the draining streams. Many of these streams flow in valleys 200 to 300 ft. in depth, and the Ohio river oc- cupies an excavated trough 500 to 600 ft. below the summits of the adjacent hills. The streams flowing southward to the Ohio are the longest and deepest, as the Mahoning, Muskingum, Hockhocking, Scioto, Little Miami, and Great Miami rivers. The Muskingum is made nav- igable by slackwater improvements to Dresden, a distance of 95 m. from its mouth. The shorter watershed on the N". side of the divide is drained by the Chagrin, Cuyahoga, Rocky, Black, Ver- milion, Huron, Sandusky, Portage, and Mau- mee rivers, none of which are navigable for any distance from the lake. Bounded on its northern margin by Lake Erie, and on its southern by the navigable waters of the Ohio river, Ohio possesses water communication through the Erie canal and St. Lawrence river with the Atlantic ocean, and through the Mis- sissippi with the gulf of Mexico. The outline of the lake shore, though but little interrupted, affords several harbors, as Ashtabula, Cleve- land, Black river, Sandusky, and Toledo. The Ohio river, 130 ft. below Lake Erie at Cincinna- ti, and 100 ft. above at the crossing of the Ohio and Pennsylvania line, is navigable for light- draught vessels to Pittsburgh, excepting during dry seasons. The soil of Ohio is universally fertile, though over more than one half of the state it is of foreign origin, being derived from the clays and gravels of the drift. The uplands are especially adapted to the growth of wheat, and for a long time Ohio was the largest grain- producing state. The southern slopes of the watershed are best fitted for the growth of grain, while the northern slopes are well suited for grazing and dairy lands; and the bottom lands of the larger rivers are among the richest corn-growing regions of the world. Though more wheat is produced in the S. "W. part than in any other equal area in the state, it is more particularly the product of the Maumee region of the northwest and the Muskingum region of the southeast. The clay soils of the northeast, 615 VOL. xii. 38 or "Western Reserve, form the great dairy re- gion of the west, and furnish 19,000,000 of the 20,000,000 Ibs. of cheese made annually in the state. The bottom lands of the larger rivers, as those of the Miami, the Scioto, and Muskin- gum, are rich alluvial soils, and as well adapted to the growth of Indian corn as any portion of the middle states. The rocks underlying the area drained by the Miami are calcareous, and the soil produced from them is of great fertil- ity, being in fact an extension of the famous blue-grass region of Kentucky. Grape culture has received careful attention in the valley of the Ohio and on the shores and islands of Lake Erie, and large quantities of wine are annually produced there. Heavy crops of apples, peach- es, and other fruits are also gathered, especially in the Miami region and on the shores of the lake. Originally almost the entire area of the state was covered by forests of oak, chestnut, maple, &c., on the highlands, and elm, beech- es, ash, &c., on the lowlands, though in the northwest there are prairies of limited extent. The wild animals, as the deer, wolf, bear, rac- coon, and fox, which once abounded in the state, have almost entirely disappeared. The geologi- cal structure of Ohio exhibits no great breaks of the strata, and the sedimentary rocks which underlie the state show only a slight inclina- tion from the horizontal. The chief disturb- ing element is the Cincinnati arch or anticli- nal, which extends from the islands of Lake Erie to Cincinnati, and beyond into Kentucky and Tennessee. From this arch the strata dip westward to the Illinois coal field, and south- eastward under the Alleghany coal basin. A study of the composition of this anticlinal shows that its elevation must have occurred at the close of the lower Silurian and previous to the commencement of the upper Silurian age, thus establishing the fact that the Illinois and Alleghany coal fields were separate and distinct basins during the deposition of their strata. The geological formations exposed in the state are the lower Silurian, upper Silu- rian, Devonian, carboniferous, and drift. The oldest rocks are those of the lower Silurian age which are exposed at and near Cincinnati, called the Cincinnati group, the equivalents of the Trenton and Hudson formations of New York. These are composed of beds of lime- stone and clay or marl, and in the richness and variety of their fossil remains are une- qualled by any other known locality. Their maximum thickness exposed near Cincinnati is about 1,000 ft. Of the formations of the upper Silurian age, the Clinton and Niagara limestones lie around and thin out upon the lower Silurian area, and are exposed at differ- ent points on the crown of the Cincinnati arch toward the lake. The Salina group, the for- mation containing the salt at Syracuse, N. Y., appears at Sandusky, 30 to 40 ft. in thickness, where it carries valuable beds of gypsum, but thins out toward the southwest and soon dis- appears. The waterlime, which represents the