geological structure of the state is simple and varies little from the horizontal. Its surface is an erosion of the paleozoie system. There is no show of granite at the surface in the state. The carboniferous, Devonian, and Silurian systems form the surface-rock geology of the state. The quaternary or drift deposits cover a large part of the state, the lowest or first of these being the unstratified blue clay known as bowider clay; the later deposit a laminate clay called by geologists the Erie clay; and above that vegetable deposits of varied character. The formation of the quaternary deposits is believed to have been going on during remote periods, during which not only alterations of the surface of prior formations were going on by elevation and subsidence, but the climate was varying radically at different periods, the region being at one time under glacial action, and at another under a climate warmer than now. The bowider blue clay is the deposit of the glacial period. The carboniferous system embraces about one-third of the state, near Portsmouth on the Ohio river for its easterly line of outcrop, and taking direction to near lake Erie; overlying the Devonian system which geologically forms the surface of the n.e. and n.w. portions of the state. The Cuyahoga shales, Berea grit, and other Ohio sandstones, from near the lake, belong to the Waverly or lowest group of the Devonian stratification. Limestone and conglomerate formations are shown in the outcrops of the w. parts of the state. The whole of the s.c. half is underlaid with the coal-bearing formations; and the geological surveys show seven dis tinct veins of coal of superior quality for domestic use or for making gas and smeltingiron The a...negate thickness of the coal beds which are convenient to work upon is about 50 feet. outcrop of the coal is along the margins of an irregular belt reaching from llifalioning co. in the n.e. to the Ohio river in the s.; the two extremities of the belt being the most prolific in coal easily quarried, and the beds in the Hocking river valley being considered the great vein coal region of Ohio. The. e. outcrop of the coal basin is seen along the Ohio river for hundreds of miles, where tunnels on the coal veins are run directly into the hills from the river slope. The most marked feature in the basic geology of Ohio is what prof. J. S. Newbery terms the Cincinnati arch, which he describes as "a great fold of the strata raised at the close of the lower Silurian age, when it formed two islands, one in Tennessee, the other in Kentucky and Ohio, around which the more recent rocks were deposited on a sloping shore. . . . In the coal-measure epoch, the Cincinnati arch was apparently a land area throughout its entire length, its northern end being' then as now its highest portion, and connected with the highlands of Canada," as shown "by the manner in which the coal-measure strata terminate on the western margin of the basin in Knox and Richland counties, where the coal-beds abut against pre-existent Waverly sandstone hills." The sandstones w. of Cleveland, n.w. cf the coal belt, form a great export of Ohio, and are used in all the cities of the northern states and Canada for elegant buildings; also for grindstones.
the coal fields already alluded to under the head of geology, iron ore of good quality has been found over an area embracing nearly one-third of the state, mostly in the e. and s. portion, along the s.e. margin of the great coal belt. Blaekbane ore is found in n.e. Ohio, and extensively used in the iron establishments of Cleveland, Massillon, Dover, and Port Washington, where they co•e mixed with other ores. The amount of iron ore mined exceeds 600.000 tons. Salt is made in considerable quantities from salt-springs, the product in 1873 being 1,400,000 /barrels. Petroleum has been raised
from oil wells in the eastern part of the state to the of 1,500,000 galls. a year. Lime for building purposes, both quick and hydraulic, is an extensive manufacture, and largely exported.
Climate.—Like all the northern United States Ohio has a wide range of temperature, running from a tropical heat during a short slimmer term to an Arctic cold in winter. The difference between the n. and s. parts of the state is what would be expected from the difference of latitude and a slight difference in elevation- the n.e. part of the state, which is the highest in latitude and altitude, being the coldest in winter and sum mer; and the s.w., at Cincinnati, proportionally warmer. The shores of lake Erie are noted for their cooling breezes in July and August; receiving a land breeze in the morn ing, and a lake breeze in the afternoon. In spring, however, they are visited by winds blowing over ice fields floating down from the upper lakes, which chill the air in April and May, when the interior of the state has the most genial temperature.
Below is given the ranges of temperature at representative points in the state: Cleveland and Toledo being on or near the lake, Portsmouth and Cinchncti the s. prints on the Ohio river, and Massillon representing the interior, on the divide s. of Cleveland. The latitude of each is given: All portions of the state are healthful at present, though there was scarcely a par where malarious diseases were not prevalent in the settlement of the country, and par ticularly in the valleys of the streams flowing into the Ohio and the w. end of lake Erie, where those ailments are now extremely rare.
Produetions.—There is probably no state of the union with less waste land than Ohio. The broken hills of the s.e., particularly noted for their products of coal and iron, are the least, and the central and w. the most, fertile. Every production of the temper ate zone may be cultivated in s^ine portion of the state, and every species of domestic animal is as profitable there as elsewhere. More than a fifth of the entire wool crop of the United States was produced in this state in 1870; nearly two-thirds of the flax; and of milk, butter, and cheese, only the state of New York produces more, or exceeds Ohio in the value of its farms per acre. The rim. part of the state, known as the Western Reserve. or New Connecticut, is the most noted dairy region; the lake borders the most valued for fruit, especis.11y grapes; the. southern part for stock; and the w. and ,s.w. for corn; yet all portions groW pretty nearly the same crops, with a slight differenee'bf adaptability.
The total value of farms in the state in 1870 was $1,054,465.226; of farming imple ments and machinery, $25,692,737; of all farm products, $198,256.907. The census return of 1880 will probably show a large increase in farm products, with but a small increase in farm valuations. The average product per acre in 1870 was, of wheat, 13.27 bush. ; corn, 36.67 bush.; oats, 32.69 bush.; rye, 11.5 bush.; barley, 23.89 bush. ; potatoes, 87 bush.; sweet potatoes, 77 bush.; hay, 1.05 tons; tobacco, 1253 lbs.
The fisheries of the state produce an important element.of its commerce. Those con ducted on a considerable scale are at the w. end of lake Erie, between the islands and the main-land for white fish, and in the Sandusky and Maumee bays and their tributaries for pickerel, bass, mullet, cat-fish, and muskallonge. The annual out-put from the fisheries of the lake and its rivers exceeds $1,500,000 of value. They are packed principally at Toledo and Sandusky for export, and are consumed in the interior.