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THE ROMA BORE. 
Generally speaking, the pressure of gas in an oil-field or gas-field 
varies roughly with the depth of the stratum below the surface, 
increasing by from 20 lbs. to 50 lbs. per square inch for every 100 feet 
of depth. Although the pressure of the gas at Roma has never been 
measured, deduction from observed facts indicates that it is no excep- 
tion to this rule. 
The No. 1 bore flowed 44,625 cubic feet of gas, accompanied by 
39,411 gallons of water, per 24 hours for some years, and consequently 
the pressure of gas where it entered the bore at 3,670 feet must at least 
have been equal to the weight of water in the bore at any one moment 
above that depth divided by the area of the cross section of the bore 
in square inches, otherwise the gas would not have been able to enter 
the bore. From these facts, the pressure can be calculated at about 
1,420 Ibs. per square inch. In the present (No. 4) bore, no gas flowed 
while the pressure of the column of water above it equalled about 1,500 
Jbs. per square inch; but as soon as the column! was lowered to a pressure 
equal to 1,340 lbs. per square inch; a flow of gas was obtained. ‘The 
pressure of the gas may, therefore, be almost certainly judged as being 
greater than 1,340 Ibs. per square inch, and as less than 1,500 lbs. per 
square inch; also as probably a little more than 1,420 lbs. per square 
inch. This is at the rate of over 39 lbs. per square inch for each 100 
feet of depth to 3,602, and is comparable with the pressures observed 
in oilfields abroad. The insignificant pressure of the gas was used 
‘as an argument against it being a gas associated with oil, but in view 
of these facts this argument appears to fall to the ground. 
Caractry oF THE Strata ror Gas. ~ 
In the present. bore (No. 4) gas was first met at 8,602 fect, and occurs 
in lower strata, in all probability, down to 3,690 feet; while in the 
No. 3 bore it was almost certainly met with down to 3,702 feet, which 
would correspond to 3,712 feet in the present bore, owing to the differ- 
ences in surface levels of the two. There is, therefore, probably a thick- 
ness of at least 100 feet of strata in this area, carrying several bands 
of sandstone from 10 to 20 feet in thickness, charged with gas at a 
pressure of at least 1,400 lbs. to the square inch. Under this pressure, 
each cubic foot of gas at the surface will occupy only one-ninetieth of 
a cubic foot in the strata, or not much more than a cube with 24-in 
sides. | 
If, therefore, the sandstones contain 1 per cent. of gas-filled spaces, 
each cubic foot of the rock would contain nearly its own volume of gas; 
and if 5 per cent. of spaces, five times its own volume. As these sand- 
stones probably extend with undiminished thickness over acres of 
ground, it will be seen that even 10 feet of sandstone carrying gas is 
likely to be capable of supplying a very large volume of gas. 
Causes or Sroppace or Frow in Previous Bones. 
This question is somewhat obscure, because we have not got all the 
details of what occurred at the time. It may have been due to sanding 
up of the bottom of the bores, or to local decrease of pressure by escape 
of gas, and flooding by “bottom” water under greater pressure. Mr. 
J. B. Henderson, Government Analyst, has pointed out that, in the 
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