THE GAS AND ITS CONTROL '279 



It is interesting to note here the presence of a limestone (Selinsgrove) 

 horizon as a portion of the Marcellus shale group, first described by the 

 writer in Eeport G7 of the Second Geological Survey of Pennsylvania, 

 from the region of Selinsgrove, on the Susquehanna Biver, in Northum- 

 berland County, as also the Corniferous limestone, with its included flint 

 nuggets, and the underlying Oriskany sandstone in which the well was 

 drilling when the tools were temporarily lost. 



The Gas and its Control 



While passing through the black slates and shales of the Hamilton 

 series above the Corniferous limestone several successive pockets of gas 

 were encountered. These had such an enormous initial pressure that 

 the escaping gas would blow the heavy tools several feet up. in the hole, 

 occasionally giving trouble from breaking of the wire cable, when they 

 would drop back after the sudden flow of gas had passed, and whose 

 approach to the surface could be heard in advance with an intense' roar- 

 ing noise. 



It will prove an interesting problem to confine and control any com- 

 mercial deposits of natural gas that may be found in the Clinton horizon 

 of this well at an approximate depth of 7,000 feet, since if the rock 

 pressure increases in the same proportion as is customary with depth, 

 namely, about 45 pounds to the square inch for every 100 feet of depth, 

 the gas pressure in the Clinton horizon should approximate 3,000 pounds, 

 a figure with which the oil and gas engineers have had but little experi- 

 ence, since no natural gas pressures have yet been recorded, in the Appa- 

 lachian field at least, which exceeded 1,500 pounds. As one means of 

 dealing with an immense pressure, and one which appears entirely feasi- 

 ble, Mr. Barger, of The People's Natural Gas Company, plans to let the 

 gas feed into the porous sands whose gas has been largely drained from 

 the upper portion of the boring, thus refilling these exhausted reservoirs 

 and finally restoring their original rock pressures, or even exceeding them, 

 from which the gas can be led into the field lines under the customary 

 rock pressures of these upper sands. In this event these higher sands 

 would act in the same manner as a reducing or regulating valve does in 

 stepping down high pressures to lower ones along the present transmission 

 lines before the gas reaches the point of consumption. 



Facilities offered fob scientific Research 



Mr. Johnson, of the United Slates Bureau of Standards, will have 

 charge of and be given every facility for securing accurate temperature 



measurements of this deep well, and as (he locality is in the undisturbed 



