been full of surprises, both to the practical men engaged in the work and to the geologists who have studied the facts as they have been brought to light, but no previous chapter of the history has proved as strange and well-nigh incredible as the discovery and development which are now to be described.

No fact in this line could be more unexpected than that any notable supplies of petroleum or gas should be furnished by the Trenton limestone, which is widely known as a massive, compact and fossiliferous limestone of Lower Silurian age and of wide extent, constituting in fact one of the great foundations of the continent. But when required to believe that certain phases of this Trenton limestone make one of the great oilrocks of our geological scale, one which produces from single wells 5,000 barrels of oil, or 15,000,000 cubic feet of inflammable gas in a day, it is hard to prevent our surprise from passing into incredulity.

Surface indications of a sulphuretted and inflammable gas, escaping from the rocky floor of the village of Findlay, have been known since the country was first settled. The gas had, in fact, been utilized in a small way, viz., in lighting a single residence for more than forty years, but in 1884 the influence of Pittsburg had made itself felt through much of Ohio and drilling was begun here. At a depth of 1,100 feet a respectable flow of gas was secured. The success of this well was the first step in by far the most remarkable development that has ever taken place in the geology of Ohio.

It was more than a year before a great gas well was discovered in Findlay, but the Karg well, which was completed in January, 1886, fully deserves this name. Its daily yield when first opened was not less than 14,000,000 cubic feet.

The discovery of oil followed that of gas by a short interval, but the prolific character of the new rock was not established till the latter half of 1886.

The rapid extension of productive territory and its equally rapid limitations, the development of several distinct centres, as Bowling Green, Lima and St. Mary's, the great speculative excitement that broke out when the good fortune of the new gas-field began to be appreciated by manufacturers and investors, and the wonderful developments that have since taken place in the line of manufactur- . ing industries, cannot be even touched upon in this connection. The salient points in the geology of the new fields are brought out in the summary that follows. The discovery comes from an unexpected quarter, viz., from the "black swamp of old time of Northwestern Ohio. Under its broad and level expanses a few hundred square miles have been found distributed through portions of five counties, within which are contained fountains of oil and reservoirs of gas of infinitely more value than any like accumulations hitherto discovered in the State, and fully deserving a place among the most

valued repositories of these substances in any quarter of the world.

The leading facts pertaining to the field can be summarized as follows:

1. In fourteen of the northwestern counties of Ohio (and like conditions prevail in contiguous territory in Indiana), the upper beds of the Trenton limestone, which lie from 1,000 to 2,000 feet below the surface, have a chemical composition different from that which generally characterizes this great stratum. They are here found as dolomite or magnesian limestone instead of being, as usual, true carbonate of lime. Their percentage of lime, in other words, ranges between 50 and 60 per cent. instead of between 80 and 90 per cent., as in the formation at large. These dolomites of Northwestern Ohio are mainly quite free from silicious impurities. The dolomitic composition seems to have resulted from an alteration of a true limestone. At least the occasional masses of true limestones charged with fossils, that are found on the horizon of and surrounded by the dolomite, are best explained on this supposition. In the change which has been endured, the fossils which the original limestones contained appear to have been for the most part discharged or rendered obscure, as is usual in this metamorphosis. crystalline character of the dolomite is often very marked, and there results from it a peculiarly open or porous structure. Its storage capacity is much greater than that of ordinary oil sandstones and conglomerates, so far at least as pores visible to the unaided eye are concerned. The change usually extends for ten to thirty feet below the surface of the formation. In some cases, however, sheets of porous dolomite are found as low as fifty feet and very rarely as low as 100 feet below the surface.

The

The area occupied by this dolomitic phase of the Trenton limestone in Ohio has already been indicated. The eastern and the southern boundaries pass through Lucas, Wood, Hancock, Allen, Auglaize and Mercer counties. It is possible that the line crosses some parts of Ottawa, Wyandot and Hardin counties.

There is good reason to believe that this phase extends far to the northward and westward, outside of the State limits to which it has here been traced. We know that the Trenton limestone is a dolomite when it pitches rapidly down from the northern boundary of Ohio to make the low-lying floor of the Michigan coal basin, and we also know that it is a dolomite when it rises from under that basin as a surface rock of the northern peninsula. In like manner it is a dolomite when it leaves the western boundary of the State under deep cover, and it is a dolomite when it reaches the surface once more in the Galena district of Illinois and Wisconsin.

South of the line laid down in Ohio there has not thus far been found a trace of the porous dolomite on which the oil of Lima and the gas of Findlay depend. The change is seen to be taking place in Shelby and

Logan counties, but beyond them the Trenton limestone is invariably found with a percentage of more than 75 per cent. of carbonate of lime, and rarely with less than 10 per cent. of silicious impurities. It is this last element, with but little doubt, that has resisted the dolomitization of the stratum throughout the southwestern quarter of the State and in all contiguous territory.

To the eastward of the line laid down in Northern Ohio, a less definite boundary is to be looked for. It is certain that small areas of porous dolomite are found beyond the line here recognized as the termination of the Findlay phase of the Trenton limestone.

Within the limits named, the limestone of course has a considerable variety of grain and texture, but all of the analyses obtained show the stratum to be in the main a dolomite. As already stated there are occasional patches or islands of true limestone in this sea of dolomite.

2. A porous rock, buried 1,000 to 2,000 feet below the surface of Northwestern Ohio, will not be found empty. Nature abhors a vacuum. With what will its pores be filled? Mainly with salt-water of peculiar composition, possibly representing the brine of the ancient seas in which the limestone was laid down. Ninety-nine-hundredths, or perhaps nine hundred and ninety-nine-thousandths of the limestone will be thus occupied. The remaining hundredth or thousandth will be filled with the petroleum and gas which have, in the long course of the ages that have passed, been gathered from a wide and general distribution through the water into certain favored portions of the great limestone sheet.

3. This salt-water will be held under artesian pressure. The porous limestone containing it rises to-day in Michigan and Illinois, communicating there with surface waters. The pressure of this head of water will be felt through every portion of the porous rock, and when the stratum is pierced by the drill in the areas that are thus occupied, the salt-water will rise with more or less promptness, depending on the varying degrees of porosity in the rock. The height to which the water will rise will seem to vary in wells, by reason of the different elevations of the locations at which they are drilled, but with reference to sea-level the water columus will be found to closely agree.

The same artesian pressure accounts for the force with which oil and gas escape when their limited reservoirs in the porous rock are tapped by the drill.

4. The accumulations of oil and gas in the porous rock depends altogether upon the attraction of gravitation. The lighter portions of the contents of the porous rock, viz., oil and gas, are forced by gravitation into the highest levels that are open to them. Everything turns on the relief of the Trenton limestone. The gas and oil are gathered in the arches of the limestone, if such they are. default of arches the high-lying terraces are made to serve the same purpose, but the one

In

indispensable element and condition of all accumulation is relief. A uniform and monotonous descent of the strata is fatal to accumulation of oil and gas where everything else is favorable. The sharper the boundaries of the relief, the more efficient does it become. Absolute elevation is not essential: all that is required is a change of level in the porous rock. Each division of the field has its own dead line or salt-water line. Saltwater reigns universal in the Findlay field 500 feet below sea-level, except where some minor local wrinkle may give a small and shortlived accumulation of oil or gas. In the Lima field the salt-water line has risen to 400 feet below tide; in the St. Mary's field to 300 feet below tide, and in the Indiana field to 100 feet below tide. These figures stand in every case for the lower limit of production, with the possible minor exceptions already noted. The rock-pressure of the gas decreases to the westward in proportion to this decreasing head of water-pressure.

The large accumulations are derived from the large terraces. The Findlay terrace, for example, consists of a very flat-lying tract, ten or twelve miles across in an east and west line, from which the connected areas of the Trenton limestone slope on every side, and to which, therefore, they are necessarily tributary. The gas terrace of Indiana is, by far, the largest of these several subdivisions of the field. The minor elevations of Oak Harbor, Tiffin and Bryan, for example, give rise to the local supplies of gas or oil in these districts respectively.

In conclusion, it is only necessary to repeat that natural gas is in all cases stored power, that there are no agencies in nature that are renewing the stocks which the rocks contain as rapidly as high pressure wells exhaust them, and that therefore economy should be observed from the outset in the use of this highly-valued source of heat and light. It is not strange that, when the surprising discovery is first made in any field, a most lavish use or rather a wanton waste of the gas is likely to prevail. It is hard to realize that such floods as rush forth can ever fail, but it is undoubtedly true that every foot of gas withdrawn brings nearer the inevitable exhaustion of the reservoir.

IV.

SOILS AND FORESTS.

The division of the State into a drift-covered and driftless region coincides as previously intimated with the most important division of the soils. Beyond the line of the terminal moraine, these are native, or, in other words, they are derived from the rocks that underlie them or that rise above them in the boundaries of the valleys and uplands. They consequently share the varying constitution of these rocks, and are characterized by considerable inequality and by abrupt changes. All are fairly productive, and some, especially those derived from the abundant and easily soluble limestones of the Upper Coal Measures, are not surpassed in fertility by any

soils of the State.

Large tracts of these excellent native soils are found in Jefferson, Belmont, Harrison, Monroe, Noble, Guernsey and Morgan counties. Wool of the finest staple in the country has long been produced on the hills of this general region.

Among the thinner and less productive soils which occupy but a small area are those derived from the Devonian shales. They are. however, well adapted to forest and fruit production. The chestnut and the chestnut oak, both valuable timber trees, are partial to them, and vineyards and orchards thrive well upon them. The north sides of the hills throughout this part of the State invariably show stronger soils than the southern sides, and a better class of forest growths. The locust, the walnut and hickory characterize the former.

The native soils of the Waverly group and of the Lower Coal Measures agree in general characters. They are especially adapted to forest growth, reaching the highest standard in the quality of the timber produced. When these lands are brought under the exhaustive tillage that has mainly prevailed in Ohio thus far, they do not hold out well, but the farmer who raises cattle and sheep, keeps to a rotation between grass and small grains, purchases a ton or two of artificial fertilizers each year, and does not neglect his orchard or small fruits, can do well upon them. The cheap lands of Ohio are found in this belt.

The other great division of the soils of Ohio, viz., the drift soils, are by far the most important, alike from their greater area and their intrinsic excellence. Formed by the commingling of the glacial waste of all the formations to the north of them, over which the ice has passed, they always possess considerable variety of composition, but still in many cases they are strongly colored by the formation underneath them. Whenever a stratum of uniform composition has a broad outcrop across the line of glacial advance, the drift beds that cover its southern portions will be found to have been derived in large part from the formation itself, and will thus resemble native or sedentary soils. Western Ohio is underlaid with Silurian limestones and the drift is consequently limestone drift. The soil is so thoroughly that of limestone land that tobacco, a crop which rarely leaves native limestone soils, at least in the Mississippi valley, is grown successfully in several counties of Western Ohio, 100 miles or more north of the terminal moraine.

The

The native forests of the drift regions were, without exception, hard wood forests, the leading species being oaks, maples, hickories, the walnut, beech and elm. walnut, sugar-maple and white hickory and to quite an extent the burr oak, are limited to warm, well-drained land, and largely to limestone land. The upland clays have one characteristic and all important forest tree, viz., the white oak. It occupies vastly larger areas than any other single species. It stands for good land, though not the quickest or most generous, but intelligent farming can

always be made successful on white-oak land. Under-draining is almost always in order, if not necessary, on this division of our soils.

The regions of sluggish drainage, already referred to, are occupied in their native state by the red-maple, the elm and by several varieties of oaks, among which the swamp Spanish oak is prominent. This noble forest growth of Ohio is rapidly disappearing. The vandal-like waste of earlier days is being checked to some degree, but there is still a large amount of timber, in the growth of which centuries have been consumed, annually lost.

It is doubtless true that a large proportion of the best lands of Ohio are too well adapted to tillage to justify their permanent occupation by forests, but there is another section, viz., the thin native soils of Southern Central Ohio, that are really answering the best purpose to which they can be put when covered with native forests. The interests of this part of the State would be greatly served if large areas could be permanently devoted to this use. The time will soon come in Ohio when forest planting will be begun, and here the beginnings will unquestionably be made.

The character of the land when its occupation by civilization was begun in the last century was easily read by the character of its forest growths. The judgments of the first explorers in regard to the several districts were right in every respect but one. They could not do full justice to the swampy regions of that early day, but their first and second class lands fall into the same classifications at the present time. In the interesting and instructive narrative of Col. James Smith's captivity among the Indians, we find excellent examples of this discriminating judgment in regard to the soils of Ohio as they appeared in 1755. The "first class land of that narrative was the land occupied by the sugar-tree and walnut, and it holds exactly the same place to-day. The second class land was the white-oak forests of our high-lying drift-covered districts. The "third class" lands were the elm and red maple swamps that occupied the divides between different river systems. By proper drainage, many of these last-named tracts have recently been turned into the garden soils of Ohio, but, for such a result, it was necessary to wait until a century of civilized occupation of the country had passed.

66

These facts show in clear light that the character of the soil depends upon the geological and geographical conditions under which it exists and from which it has been derived.

C.

THE CLIMATE OF OHIO. From its geographical situation the climate of Ohio is necessarily one of extremes. The surface of the State is swept alternately by southwest return trades and northwest polar winds, and the alternations succeed each other in quick returning cycles. There is scarcely a week in the year that does not give exam

ples of both currents.

All other winds that blow here are tributary to one or other of these great movements. The return trades or southwest winds are cyclonic in their character; the northwest winds constitute the anti-cyclone. The former depress the mercury in the barometer and raise it in the thermometer; the latter reverse these results. The rains of the State are brought in by southwest winds; the few cases in which notable precipitation is derived from currents moving in any other direction than from the southwest really make no exception to the general statement, for in all such instances the rain falls in front of a cyclone which is advancing from the Gulf of Mexico. The protracted northeast storms that visit the State at long intervals and the short southeast storms that occur still less frequently are in all cases parts of greater cyclonic movements of the air that originate in the southwest and sweep out to the ocean over the intervening regions.

Between the average summer and winter temperatures of the State there is a difference of at least 40° Fahrenheit. A central east and west belt of the State is bounded by the isotherms of 51° and 52°, the average winter temperature being 30° and the average summer temperature being 73°. Southern Ohio has a mean annual temperature of 54° and Northern Ohio of 49°.

66

The annual range is not less than 100°; the maximum range is at least 130°; the extreme heat of summer reaching 100° in the shade, while the cold waves "of winter sometimes depress the mercury to 30° below zero. Extreme changes are liable to occur in the course of a few hours, especially in winter when the return trades are overborne in a conflict, short, sharp and decisive, with the northwest currents. In such cases the temperature sometimes falls 60° in 24 hours, while changes of 20° or 30° in a day are not at all unusual.

The winters of Ohio are very changeable. Snow seldom remains thirty days at a time over the State, but an ice crop rarely fails in Northern Ohio, and not oftener than once in three or four years in other parts of the State. In the southern counties cattle, sheep and horses often thrive on pasture grounds through the entire winter.

In spite of these sudden and severe changes the climate of Ohio is proved by every test to be excellently adapted to both vegetable and animal life. In the case of man and of the domestic animals as well, it certainly favors symmetrical development and a high degree of vigor. There are for example no finer herds of neat stock or sheep than those which are reared here.

The forests of the State have been already described in brief terms. The cultivated products of Ohio include almost every crop that the latitude allows. In addition to maize, which nowhere displays more vigor or makes more generous returns, the smaller grains all attain a good degree of perfection. The ordinary fruits of orchard and garden are

produced in unmeasured abundance, being limited only or mainly by the insect enemies which we have allowed to despoil us of some of our most valued supplies. Melons of excellent quality are raised in almost every county of the State. The peach, alone of the fruits that are generally cultivated, is uncertain; there is rarely, however, a complete failure on the uplands of Southern Ohio.

The vast body of water in Lake Erie affects in a very favorable way the climate of the northern margin of the State. The belt immediately adjoining the lake is famous for the fruits that it produces. Extensive orchards and vineyards, planted along the shores and on the islands adjacent, have proved very successful. The Catawba wine here grown ranks first among the native wines of Eastern North America.

The rainfall of the State is generous and admirably distributed. There is not a month in the year in which an average of more than two inches is not due upon every acre of the surface of Ohio.

The

The average total precipitation of Southern Ohio is forty-six inches; of Northern Ohio, thirty-two inches; of a large belt in the centre of the State, occupying nearly onehalf of its entire surface, forty inches. tables of distribution show ten to twelve inches in spring, ten to fourteen inches in summer, eight to ten inches in autumn and seven to ten inches in winter. The annual range of the rainfall is, however, considerable. In some years and in some districts there is, of course, an insufficient supply, and in some years again there is a troublesome excess, but disastrous droughts on the large scale are unknown, and disastrous floods have hitherto been rare. They are possible only in very small portions of the State in any case. There is reason to believe, however, that the disposal of the rainfall has been so affected by our past interference with the natural conditions that we must for the future yield to the great rivers larger flood plains than were found necessary in the first hundred years of our occupancy of their valleys. Such a partial relinquishment of what have hitherto been the most valuable lands of the State, not only for agriculture, but also for town sites and consequently for manufactures and commerce, will involve immense sacrifices, but it is hard to see how greater losses can be avoided without making quite radical changes in this matter.

In February, 1883, and again in February, 1884, the Ohio river attained a height unprecedented in its former recorded history. In the first year the water rose to a height of sixty-six feet four inches above the channelbar at Cincinnati, and in the latter to a height of seventy-one feet and three-fourths of an inch above the bar. The last rise was nearly seven feet in excess of the highest mark recorded previous to 1883. These great floods covered the sites of large and prosperous towns, swept away hundreds of dwellings, and inflicted deplorable losses on the residents of the great valley.

Are floods like these liable to recur at short intervals in the future? The conditions under which both occurred were unusual. Considerable bodies of snow lying on frozen ground were swept away by warm rains before the ground was thawed enough to absorb and store the water. These were the immediate causes of the disastrous overflows in both instances, and it may well be urged that just such conjunctures are scarcely likely to recur for scores of years to come. But it is still true that we have been busy for a hundred years in cutting down forests, in draining swamps, in clearing and straightening the channels of minor streams, and finally, in underdraining our lands with thousands of miles of tile; in other words, in facilitating by every means in our power the prompt removal of storm-water from the land to the nearest water-courses. Each and all of these operations tend directly and powerfully to produce just such floods as have been described, and it cannot be otherwise than that under their combined operations our rivers will shrink during summer droughts to smaller and still smaller volumes, and, under falling rain and melting snow, will swell to more threatening floods than we have hitherto known. The changes that we have made and are still carrying forward in the disposal of storm-water renders this result inevitable, and to the new conditions we must adjust ourselves as best we can.

and towns. The amount of these impure additions is constantly increasing, the rate of increase being in fact much greater than the rate of growth of the towns. The necessity of removing these harmful products from the places where they take their origin is coming to be more generally recognized, and sewerage systems are being established in towns that have heretofore done without them. It thus happens that, as the amount of water in the rivers grows less during summer droughts from the causes already enumerated, the polluted additions to the water are growing not only relatively but absolutely larger. When, now, we consider that these same rivers are the main, if not the only, sources of water supply for the towns located in their valleys, the gravity of the situation becomes apparent. It is easy to see that the double duty which we have imposed upon the rivers of supplying us with water and of carrying away the hateful and dangerous products of waste, cannot long be maintained. There is no question, however, as to which function is to be made the permanent one. The rivers cannot possibly be replaced as sources of water-supply, while on the other hand, it is not only possible but abundantly practicable to filter and disinfect the sewage, and, as a result of such correction, to return only pure water to the rivers. During the first century of Ohio history not a single town has undertaken to meet this urgent demand of sanitary science, but the signs are multiplying that before the first quarter of the new century goes by the redemption of the rivers of Ohio from the pollution which the civilized occupation of the State has brought upon them and their restoration to their original purity. will be at least well begun.

Another division of the same subject is the increasing contamination of our rivers in their low-water stages. This contamination results from the base use to which we put these streams, great and small, in making them the sole receptacle of all the sewage and manufacturing waste that are removed from cities