566 ME. C. DAWS02J" ON THE DISCOTERT OP [Aug. 1 898, 



Coupled with this also we must consider the pressure exerted by a 

 column of water, which, when the tube is clear, stands at 260 

 feet, and thus exerts the pressure of about 8 atmospheres ( = about 

 120 lbs. per square inch), which the gas at the bottom must over- 

 come before it can make its way through the porous strata into 

 the tube. 



Under the present conditions, when the gas is allowed to escape 

 freely from the 6-inch outlet, when all abnormal pressure of col- 

 lected gas in the empty tube above the water has been dissipated, 

 and the tube is connected to a gas pressure-gauge, it shows a 

 pressure of 20 tenths of an inch of water, rising to 180 tenths (the 

 limit of the gauge employed) in 25 minutes when the water at the 

 top of the gauge is forced out. 



Under the same conditions, the amount of gas supplied, tested by 

 a 10-light dry meter (|-inch outlet), with a pressure of 20 tenths 

 maintained in the bore-tube, amounted to 12| cubic feet per hour. 



III. Analysis op the Gas. 



The gas has been analysed on the spot by Mr. S. A. Woodhead, 

 B.Sc. (the County Analyst for East Sussex), who kindly conducted 

 the experiment for the purpose of this paper.^ He reports as 

 follows : — 



[July 7th, 1898. 



I examined the natural gas at Heathfield Station on Jan. 26th & 27th, 

 1898, and found the gas as it issued from the bore-tube to be colourless, neutral 

 to test-papers, and possessing a faint paraffin -like odour. When mixed with 

 air it was extremely explosiye. It possessed great heating properties, and gave 

 a fine flame in a Bunsen burner, 



I analysed the gas, and found its approximate composition to be as 

 follows : — 



Per cent. 



Oxygen 18 



Higher hydrocarbons 5'5 



Carbon monoxide 4*0 



Marshgas^ 725 



Total 100-0 



The presence of so much oxygen was surprising, but nevertheless it was 

 present, and in such proportion as to make the gas slightly explosive. It was 

 so remarkable that I carried out the analysis twice, with similar results within 

 a few decimal places. 



There were no impurities in the gas, such as ammonia, hydrogen sulphide, 

 or carbon dioxide. 



The water standing in the borehole, through which thousands of feet of gas 

 must have passed, was analysed by me with a view to discover these impurities, 

 but beyond the discovery of 0'2 parts per million of ammonia nothing remarkable 

 was noticed. The analysis points to the gas being a petroleum-derivative. 



Sam. a. Woodhead, 

 Public Analyst.'^ 



^ He fitted up a laboratory on the spot, and checked all his results twice. 



^ On explosion with oxygen on two separate occasions there appeared to be 

 the slightest sign of expansion, which probably indicated the presence of a 

 little ethane. 



