190 I. C. WHITK — THE MANNINGTON OIL FIELD. 



Feet below Lbs. per 



/"'■ . sq. in. 



Gas in Pottsville conglomerate at Mannington 200-300 350-400 



(las in Mount Morris sand at Mount Morris and Mannington. 700 500-550 



Gas in Mount Morris sand at Blacksville 800 600 4- 



( ras in Mount Morris sand at Harrisville (West Virginia). . . . 1,000 680 4- 



Gas in Gordon sand near Pittsburg 1,000 800 4- 



Gas in < rordon sand near Waynesburg 2,000 1,300 + 



The same story is told by any other set of observations, viz, that for any 

 particular stratum the amount of pressure its gas develops is directly 

 proportional to its depth in about the same ratio which a column of 

 water increases pressure with increasing length. 



Since the column of salt water never rises to the surface through south- 

 western Pennsylvania and West Virginia, and since it is almost impossi- 

 ble to get the oil drillers to make accurate measurements down to the top 

 of the water in any particular case, exact calculations as to what the 

 theoretical pressure should be have not been made, though from close 

 estimates by cable measurement of the height of the column of water it 

 is known that the observed pressure in all of the "white sand " oil and 

 gas rocks of West Virginia and southwestern Pennsylvania corresponds 

 very closely with what it should be on the hypothesis of artesian origin. 

 Hence these facts have precluded any other interpretation, and this origin 

 for the gas and oil pressure has entered into all of my reasoning upon 

 these problems. 



I am aware that Professor Lesley * finds (for himself) an argument for 

 the ' ; expansion theory " of gas pressure in the gradual decline of the gas 

 pressure at Murraysville and Grapeville; but he overlooks some very 

 simple truths. During a great lire in a town supplied with water by 

 elevated reservoirs (artesian pressure), when a dozen fire plugs are open 

 and running under full headway, the pressure in all the street mains is 

 greatly reduced, and yet the height of the column of water (reservoir) 

 remains the same, and the original pressure will return when the fire is 

 over (the water plugs being closed). Also in the distribution of illumi- 

 nating gas, the pressure rapidly decreases soon after dark, when so many 

 exits for the gas have been opened (gas jets lighted), though the pressure 

 remains the same at the gas-holders, or has even been increased. The 

 underground tankage of gas is an exactly paraded case to that of water 

 or gas above ground, with the exception that freedom of movement must 

 be infinitely greater above than below ground, on account of the capillary 

 nature of the underground conduits; and hence a priori we should ex- 

 pect that the opening of several exits for the escape of the subterranean 

 gases would be more marked in decreasing the pressure upon such con- 



*Proe. Am. Phil. Soc, vol, xxix, 1891, p. 10, 



