Lesley.] 



16 



[March 6, 



ville field, as it may be found in better condition in the central and north- 

 ern parts of the field. Carnegie Bros, have begun drilling two or three 

 wells to test the Gordon sand a little north of the centre of the Gants 

 field, a mile from No. 10 (Sylvis well). 

 None of the Latrobe wells are piped to Johnstown. 



Grapemlle. Table of Minute Pressures at Various Dates. 



The steady decline in minute pressure from 386 Ibs. on April 20, 1889, to 

 65 Ibs. on February 2, 1891, predicts a speedy extinction of the use of 

 natural gas at the Cambria Works. 



Calculating the average rate per day of the observed decrease we find it 

 to be as follows : 



From April 29, 1889, 643 days, 321 Ibs. 2 Ibs. per day. 



From Dec. 16, 1889, 413 

 From May 26, 1890, 252 

 From Nov. 3, 1890, 91 

 From Dec. 1, 1890, 63 

 From Jan. 5, 1891. 28 



188 " 2.200 " 

 107 " 2.355 " 

 36 " 2.525 " 

 30 " 2.100 " 

 7 " 4 Ibs. " 



I take this opportunity to suggest that we have in the decline of gas 

 pressure in all wells of all gas regions the most cogent of arguments 

 against the theory that gas pressure is produced by the hydrostatic pres- 

 sure of the locality. For, it is self-evident that the hydrostatic pressure 

 must remain always the same, and therefore cannot be the vis a tergo 

 of a variable oil or gas pressure ; otherwise this last should also remain 

 constant to the last drop of oil and the last cubic foot of gas coming from 

 the well. The gradual decline of gas pressure in every well and all 

 wells is proof positive that it represents the gradual exhaustion of an in- 

 herent force of self-expansion not dependent upon any hydraulic ms a 

 tergo. 



