A few figures in the same line are given from counties outside of the limits that have been considered: Many of these records are derived from drilling done in the valleys of central and southern Ohio, and thus serve to show the great amount of pre-glacial erosion that these regions have endured. A few examples are appended: NOTE.-The list above given can be greatly increased in value if those who read this chapter will forward to the author any additional facts pertaining to this subject. Low-water at Cincinnati is counted 440 feet above mean tide. By examination of the facts given above, in connection with the surface elevations of the locations of the wells, it is seen that this ancient erosion has been in several instances carried below the lowest point from which, at the present day, water can be drained, within the limits of the state. The deep excavations shown in the Dayton well and in the Hamilton well, as well as in the Cincinnati records, are examples of this sort. At these, and many other points, the erosion has reached several hundred feet below the present drainage levels of the districts within which these wells are included. What is counted above as thickness of the drift is very likely to be in some cases a few feet in excess of the facts. The length of the drive pipe may have been given instead of the exact thickness of the drift beds. The drive pipe is generally carried a few feet into the underlying bedded rock. CHAPTER XVII. SUPPLEMENTAL REPORT ON THE NEW GAS FIELDS AND OIL FIELDS OF OHIO. BY EDWARD Orton. In the brief chapter which is here to follow, a few of the latest facts in regard to gas and oil from the new horizons will be stated. THE CLINTON LIMESTONE. Lancaster. On pages 382-388 an account is given of the important discovery at Lancaster of a source of high-pressure gas in respectable volume in the Clinton limestone. The facts there presented have been supplemented in the interval that has passed since they were put in type. Two additional wells have been drilled since that date, the records of which are as follows: Well No. 4 is located on the west side of town, at the brewery, about one-half mile south of No. 2. Gas was struck at a depth of 1950 feet, and the daily flow, as measured by Professor G. W. Welch, superintendent of schools, is 650,000 feet per day. This flow is from a 4 inch pipe. Well No. 5 is one-half a mile south of No. 4. It was completed in February, 1888. It found gas at 1940 feet, and its daily production is 260,000 feet per day, from a 44-inch pipe. On page 387 the prediction was made that a closed pressure far in advance of the Findlay field would be found in the Lancaster wells. This prediction is verified, at least in part, in the following table, viz.: Closed or rock-pressure of Well No. 1................355 pounds to square inch. Closed or rock-pressure of Well No. 2.................285 pounds to square inch. Closed or rock-pressure of Well No. 3................ 310 pounds to square inch. Closed or rock-pressure of Well No. 4.................700 pounds to square inch. The last figure, derived from the most recently completed well of the list, probably exhibits the normal rock pressure of the field. The table of production of the five wells now completed is appended: None of the wells have been torpedoed except No. 1, and the measurement of this, as above given, was taken before the shot. Wells Nos. 2 and 3 are furthest north, and the inference from present developments is obvious that the best promise is to be found in that direction. The cost of the wells has been greatly reduced since the facts of the section have come to be understood. The last two wells have cost only about $3,500 each. Well No. 4 was put down in thirty-seven days. For the facts of the Lancaster field, including the measurements of the last two wells, the Survey is under great obligation to Superintendent G. W. Welch. It is to this gentleman as much, to say the least, as to any other that Lancaster owes her present good fortune in a natural gas supply. The town is rapidly being piped, and the introduction and use of the gas give great satisfaction. THE TRENTON LIMESTONE. A good deal of drilling has gone on in and around Tiffin during the last few months. The success of the Loomis and Nyman well, described on page 199, has revived the interest in the search, and two of the six wells since drilled have started out with a production of considerable value. The most recent testimony is, however, to the effect that this production is not well-sustained, oil having followed the gas very closely. This implies that the arches for gas accumulation are small. The record of the wells is summarized below: Powell Well, one-eighth mile below Loomis and Nyman well, in river valley. Trenton limestone reached at....... ...........1455 feet. Harshberger Well-Trenton limestone reached at........ Drilled to depth of............... King Well, one mile northeast of town. Trenton limestone reached at ..... ..1547 feet. ........1753 feet. .....1605 feet. Eureka Well, two squares east of Loomis & Nyman well. Trenton limestone reached at.. Well torpedoed in November, 1887. .1484 feet. .....1647 feet. ....1467 feet. Production estimated at 2,000,000 cubic feet per day. Welch well, located in town, south of Pennsylvania R. R. station. Depth in Trenton..... Production estimated at 400,000 cubic feet per day. Fanning well, 600 feet north and a little west of Welch well. Depth in Trenton limestone.. .1455 feet. 24 feet. .1459 feet. ..22 feet. 'Production estimated at 1,250,000 cubic feet per day. In the last named well, which was finished in February, 1888, the gas-rock was found much looser in texture than in any well previously drilled. Its natural flow was also greater, but the increase by "shooting" was much less than had been gained in the other productive wells. It is free from oil as yet, but the days of its exemption are probably numbered. The wells, when shot, produce dry gas for about five weeks. At the end of that time, the oil appears with the gas and in the case of the wells whose production is largest, it gains rapidly at the expense of the gas, choking it out in a short time. The Powell well has already been overrun so as to be valueless for gas. The smaller well of Loomis and Nyman produces about two barrels of oil per day, without any decided loss of gas so far as noted. It was torpedoed with a small shot a few months since, and its flow is reported as increased thereby several fold. It is now said to carry the boiler connected with the works, ten large stoves, the melting pots for Babbit metal and brass, the core ovens and twenty or thirty torches for illumination. Its rock pressure is, however, rapidly declining. Before the well was torpedoed, the pressure was at least 650 pounds to the square inch (see page 200). At the present time it never rises above 325 pounds. These facts serve to indicate the real nature of the Tiffin field. A well marked fold passes through the center of the town, but it is of |