counties already reported. There is nothing in them to break the record of failure that fills the preceding pages.

It is quite likely that some of these counties, especially Harrison and Monroe, deserve to be tested still further in respect to gas and oil supplies. It is believed that light folds of the strata traverse one or both of them, on which some probability, or at least possibility, of production might well enough be based.

The accounts that have been given do not, by any means, exhaust the list of the tests that have been made in eastern Ohio during the last three years. The reports thus far presented are designed to be representative, rather than complete. As far as possible, the experimental drilling of the leading towns has been reported. Scores, and, perhaps, hundreds of wells have been passed without notice in this account, but while every record, if carefully studied, will doubtless furnish new and interesting facts, it is not likely that any large results have been missed.

The facts that have now been presented are undeniably discouraging as to the presence of valuable, and, at the same time, wide-spread accumulations of gas and oil throughout central Ohio.

The main reliance of this part of the state must be placed on the Berea grit, as has been already demonstrated, and this stratum has failed, in the large way, to meet the demand that has been thus placed upon it.

It is nowhere wanting in the source of gas. A supply adequate to all demands is to be found in the great series of Ohio shales, 500 to 2,500 feet in thickness, which everywhere underlie the Berea grit. Neither does this stratum lack the porosity which is essential to the storage in it of gas and oil. It is, however, often thin, and sometimes it becomes too fine-grained or close, to serve a good purpose as a reservoir. The general porosity of the rock is, however, abundantly attested by the presence of salt-water in it to so large an extent. Again, the Berea grit never lacks the good cover necessary to oil and gas production. The shale series overlying it meets all demands in this respect. What, then, is wanting to make the series a source of large production? The answer is brief. It lacks proper structural conditions. The series of strata within which it is included is found to be wanting in due relief. The Berea grit descends uniformly from its outcrops to its deepest stations in the state, and in this prolonged slope there are no such interruptions as are necessary to the accumulation of oil and gas. Some arches and terraces there are, but they are overrun by salt-water very soon after they are penetrated by the drill.

What, then, are the prospects of eastern Ohio for natural gas? There is no mistaking the answer given by the drill. It has been constantly kept at work for the last three years. A geological survey, of a very expensive sort, has been in progress. At the lowest calculation, $500,000 have been spent upon it in eastern Ohio since 1884. With what result? Aside from the Macksburg field, the returns for all this outlay are insignificant. For far the larger number of instances there is nothing whatever, to be placed to the credit side of the account.

What has been will be. The discovery at any time of small productive fields, like Macksburg, within the large territory now under consideration, should occasion no surprise. Such discoveries are, in fact, to be expected. But the ground has already been so widely tested, that it is safe to say that such discoveries must be confined within quite narrow limits. It does not seem probable that any of these productive tracts lie within easy striking distance of the towns and cities that so greatly need and desire an abundant supply of natural gas.

A few statements need to be made in regard to the composition of the gas from the Berea grit.

On page 135, the analyses of Pittsburgh gas made by Mr. S. A. Ford, are given and discussed. The remarkable character of the analyses was noted, but not questioned. It was supposed that so anomalous and surprising results would not have been published unless they had been established beyond all question. This conclusion has proved to have been a mistaken one.

The subject of the composition of natural gas from the various horizons of western Pennsylvania, has been more recently investigated by Professor Francis C. Phillips, of the Western University, Allegheny, for the Geological Survey of Pennsylvania. This report has been published in the American Manufacturer, in advance of the Annual Report of the Survey, and has thus become available for use. The investigation appears to have been carried on in recordance with the best methods known to science, and the report bears upon its face the marks of the most scrupulous care and the most conscientious painstaking.

The anomalous features of the results before announced all disappear, and Pittsburgh gas is seen to be a steady and self-consistent product. It agrees, very closely, in composition with Findlay gas, as determined by Professor Howard, two years since. Both contain about 90 per cent. of hydro-carbons. The main difference is in the presence of a small amount of sulphuretted hydrogen in one, and its absence from the other. The subject cannot be further discussed here, but we are sure that the gas of the Berea grit, and, also, of the underlying shales in Ohio, will show the same general constitution that is reported by Professor Phillips, from western Pennsylvania. A few of his analyses are herewith given. In them we see, for the first time, the true constitution of the natural gas of the most famous fields of the country. The analysis of the shale gas of Fredonia, N. Y., is added to the list:

(Murrysville). Lyon's Run

Fredonia, N. Y.

CHAPTER V.

THE OHIO SHALE AS A SOURCE OF OIL AND GAS IN OHIO.

BY EDWARD ORTON.

The most widely extended and the best known source of natural gas in the state, but not the most valuable, remains to be considered, viz., the Ohio shale. This complex formation has already been described at some length in Chapter I, and frequent reference to it has been necessary in the chapter on the Berea grit.

There are two main areas of the Ohio shale in the state, the principal one entering from the east along the shore of Lake Erie, and forming the border of the lake as far west as Sandusky, with a breadth varying from ten to thirty miles. From Sandusky the formation stretches southward with about the same breadth of outcrop as already described in a direction slightly west of south, to the Ohio Valley. The two areas occupy four or five counties, in whole or in part, in the extreme northwestern corner of the state, but these counties are heavily covered with drift, and consequently but little is known of the underlying shale formation, and its influence upon the surface is reduced to a minimum. There is a third small area in Logan county, occupying the highest land of the state. There are, of course, numerous outliers, small and great, along the western margin of the largest area, which are counted with it. All of these are shown on the accompanying sketch map.

The first of these divisions, whose northern and western edges have now been traced, is co extensive, in outcrop and under cover, with the limits of eastern Ohio, and indeed it stretches far beyond these boundaries into adjacent states.

The shale formation is thinnest to the southwestward. In Highland and Adams counties, included sections are found which do not exceed 250 feet in thickness. In Ross and Pike counties, the measure becomes a hundred feet greater, and still further to the eastward a rapid expansion is found. These facts are illustrated, in part, in the section of the preceeding chapter in which the rocks between Columbus