442 GEOLOGY OF NORTHWESTERN TEXAS. 



The most noted place for the use of natural gas is Pittsburg, Pa. There 

 the matter has been fully tested and has proven every way satisfactory. The 

 supply of gas for that place is obtained at a distance of twenty-four miles and 

 less, and is conducted into the city by pipes ranging from thirty to five inches 

 in diameter. The wells vary in depth from fifteen hundred to two thousand 

 feet, and range from three to eleven inches in diameter. The amount of gas 

 obtained from a well varies greatly. It has been found that all wells of the 

 same size and same pressure are not equal gas producers. Therefore the 

 amount of gas that the different wells give in the same district varies consid- 

 erably. It has also been found that an occasional "dry hole" has been struck 

 in localities in the immediate vicinity of good gas producers. The average 

 number of dry holes in the Pittsburg district is about one in ten. The cause 

 of this is that there are places in the gas bearing stratum that are impervious 

 to the gas, and when such a place as that is passed through there will be no 

 flow of gas. This can sometimes be remedied by blasting or breaking up the 

 stratum at the place, but such is not always the case. 



GAS BEARING STRATA. 



A few necessary conditions must exist before it is possible for a stratum 

 to be gas bearing. No gas can be found in the oldest strata. Nothing can 

 be gas bearing below the Silurian. There can be no gas where the rocks 

 have been greatly disturbed by upheavals, and where the rocks stand at a 

 great angle. Even if there ever had been any gas in them, it has long since 



Where the formation is very nearly flat over extensive districts of country, 

 there is a possibility of finding gas, no matter to what period the strata may 

 belong. 



There is a popular notion that the Trenton limestone is the only bed in 

 which gas or oil can be obtained, and I have received several communica- 

 tions asking if that formation was to be found in the State. The fact is, that 

 oil and gas are not confined to any formation, and have been found all the 

 way from the bottom of the Silurian to the glacial drift. 



Gas is produced by the decomposition of animal and vegetable substances, 

 and has been stored up in caverns, cracks, and porous beds, awaiting the pros- 

 pector's drill. Whether the gas is still forming might be a question that 

 would admit of dispute, yet it is thought that the supply in a gas bearing 

 stratum, when once penetrated, will be practically inexhaustible for a great 

 number of years. 



GAS IN TEXAS. 



There has been no effort to obtain gas anywhere in the part of the State 

 to which this Report refers. Yet at numerous places holes have been put 



