limestones were found 440 feet thick. At 470 feet, the red Medina shale was struck. It continued thirty feet. At 1,260 feet or 450 to 460 feet below tide, the Trenton limestone was reached. At 1,266, a little gas was reported, and at 1,270 a small vein of salt-water. A little oil came in at 1,276 and a heavy vein of salt-water at 1,288 feet. At 1,290 feet a little more oil appeared. The well was finished at 1,334 feet, but it was a complete failure.

A list of the wells of the Findlay field complete to April 1886 is herewith given:

From this table it will be observed that but one out of seventeen wells had proved unproductive up to this time. The territory was thus shown to be unusually reliable.

PRODUCTION OF THE FIELD.

The total gas production of the wells at this date was about 25,000,000 cubic feet per day, as commonly counted. It is not to be understood, however, that this entire amount was at any time available for actual

use.

The measurements were made from the initial and presumably the largest production of the wells, and also were made at the well-heads, and often from the casing at that. When the wells are packed and tubed with smaller pipe, and especially when the gas is conveyed by the distributing lines through the town, a considerable reduction is encountered, no record of which is found in these reports. The loss from transportation is, however, less in Findlay than at most other points, the wells being at the doors. Such measurements are, however, valuable in showing the normal energy and productiveness of a field.

But counted in any way, the production of Findlay gas was up to this time vastly in excess of all the demands of the town. A tenth or twentieth, even, of the supply would have been ample for every use for the year 1886.

Obtained as it was in enormous volume and at insignificant expense and with no signs of reduction or failure apparent, and especially falling into the possession of a community entirely without experience as to the nature of petroliferous supplies, a very reckless mode of use was introduced, to which was added a more reckless and even an unpardonable waste. There were several months in the early part of 1886 in which not less than 18,000,000 cubic feet of the best fuel known to man were blazing into the air every day in and around Findlay. The Karg well is responsible for a large part of this loss. Its great volume made it hard to subdue, and this fact furnishes some excuse for the enormous drain that it inflicted on the stock of the Findlay reservoir during the four months that it was uncontrolled. The total loss to the field from this single source cannot be less than 1,500,000,000 cubic feet of gas.

The progress of Findlay and its new interests since the date abovenamed has been remarkable. This progress has not consisted so much in unlocking more gas from its great reservoir, though several new wells have been brought in, as in utilizing what had already been secured. In this short interval, the town has become an important manufacturing center. Its growth has been in a measure proportioned to its unparalleled supply of fuel, and it is still going forward on a very large and promising scale.

STRUCTURE OF THE FIELD.

It is not counted necessary to follow further the records of individual wells, except in cases of unusual ones. The laws of the field are to be

through Findlay on 'a Tine bearing N.57°W
Section from Gas Works Well to Karg Well No.2

found in the figures already given, and the new experience is mainly within the limits of the first tests. Dry gas comes from the Trenton limestone when it holds a level of 312 feet below tide to something below 350 feet below tide. The original level of dry gas reached down to 400 feet below tide, but this lower portion of the rock has been overrun with oil or with oil and salt-water. The strongest wells obtain their gas from 330 to 350 feet below tide. The oil level, on the other hand, extends from 400 feet to nearly 500 feet below tide. The latter level is the downward limit or dead-line in the field, below which nothing of value is found. Salt-water rises in this outside territory to within 100 or 200 feet of the surface and sometimes it even overflows. The greatest oil production is found at 460 to 480 feet below tide.

The geological structure of Findlay also comes out to view in the same sets of figures. Two terraces of Trenton limestone, separated by an interval of 150 feet, are seen to be connected by a steep slope, on the edge of which the Karg well is located, and half-way down the Adams and Barnd wells are found. These facts are represented in the accompanying diagram, in which an accurately drawn section from the gas-works well to the Karg well, No. 2, is shown. The latter is an oil-well of moderate capacity. From the Karg well, No. 1, to Karg, No. 2, the descent of the Trenton is 121 feet, the elevations of the surface being the same, and the distance between them being but little more than 1,200 feet.

COMPOSITION AND USES OF FINDLAY GAS.

The question, what is natural gas, is as hard to answer as the question, what is coal. Both substances sweep through a wide range of chemical composition, without losing their names. The fire-damp of the mine is natural gas; so, also, are the inflammable gases arising from the decomposition of organic matter.

The gas released by the drill from its rock reservoirs consists largely of what is commonly known as marsh gas or light carburetted hydrogen, the chemical composition of which is expressed by the notation CH4. But with the marsh gas are varying proportions of numerous other simple and compound gases, including the elements of the atmosphere, The best analyses of Pennsylvania gas are those of Mr. S. A. Ford, chemist of the Edgar Thompson Steel Works. They have been widely quoted, as they deserve to be, on account of the surprising and important character of the information that they furnish.

They prove that the gas in use at Pittsburgh is unstable in composition, and that no one analysis, however accurate, would do any justice to the facts.

Its composition, as determined by the average of six analyses, (1) is given by Mr. Ford as follows: the composition of three of the samples is also added, (2), (3) and (4), to show the range:

The samples were taken from the same well on different days of two months. Such variability would be expected to produce more irregularity in use than has been reported. It must certainly be an advantage to the user to adjust the supply to the work to be done, and to know that, aside from the influence of atmospheric changes, he can be sure of his result.

This advantage of constancy of composition belongs to the gas derived from the new horizon. Findlay gas was first accurately analyzed by Prof. C. C. Howard, for the Ohio Geological Survey, in 1886. Its composition was found to be as follows:

After an interval of several months a new analysis was made, and the figures were found to agree with those previously obtained within the limits of error involved in the processes themselves. More significant still are the results of Professor Howard's re-determination of Findlay gas, for the United States Geological Survey, in the summer of 1887. Tο these results, which agree as closely as could be desired with the figures originally obtained, are added the composition of Fostoria gas, St. Mary's gas, and the gas of four well-known centers of production in the Indiana field, viz., Muncie, Anderson, Kokomo and Marion. The very important fact is brought to light that all of this production is of one piece. The differences in results would all be included within the limits