134 THE ADDRESSES, LECTURES, ETC., OF 



ever, it is found separated from the coal with which it may have 

 been primarily associated, and in those cases it has been made 

 practically available as fuel. At Bakoo, on the Caspian Sea, 

 natural gas has issued spontaneously from the ground for centuries 

 past, and the column of perpetual fire thus produced, has served 

 the purpose of giving the Parsees a holy shrine at which to worship 

 their deity. In the district of Pennsylvania, a more substantial 

 application has been made of the gas issuing from many of the 

 borings, which serves as fuel for working pumping machinery and 

 as illuminating gas for the district. The quantity of gas issuing 

 from some of these wells may be judged from the fact, that one 

 of them, after discharging for three years as much gas as could 

 escape into the atmosphere under a pressure estimated at not less 

 than 200 Ibs. on the square inch, has lately been connected by 

 means of a 5-inch pipe with Pittsburg (a distance of 18 miles), 

 where 70 puddling and re-heating furnaces are worked entirely by 

 thg fuel so supplied. But even this result furnishes only an im- 

 perfect idea of the calorific power represented by this single issue 

 of natural gas, inasmuch as the combustion is carried on in these 

 furnaces on the most wasteful plan, the gas being mixed imper- 

 fectly with cold air, and converted to a large extent into dense 

 masses of smoke. An analysis of this gas gives Hydrogen, 13*50 ; 

 Marsh Gas, 80-11 ; Ethylene, 5'72 ; Carbonic acid, 0'66. 



The use of natural gas is not likely to assume very large pro- 

 portions owing to its rare occurrence, but its application at Pitts- 

 burg has forcibly reminded me of a project I had occasion to put 

 forward a good many years ago, namely, to erect gas-producers at 

 the bottom of coal mines, and by the conversion of solid into 

 gaseous fuel, to save entirely the labour of raising and carrying 

 the latter to its destination. The gaseous fuel, in ascending from 

 the bottom of the mine to the bank, would (owing to its tempera- 

 ture and low specific gravity), acquire in its ascent an onward 

 pressure sufficient to propel it through pipes or culverts to a con- 

 siderable distance, and in this way it would be possible to supply 

 townships with heating gas, not only for use in factories, but, to a 

 great extent, for domestic purposes also. In 1869, a company, in 

 which I took a leading interest, was formed at Birmingham, under 

 the sanction of the Town Council, to supply the town of Birming- 

 ham with heating gas at the rate of Gd. per 1,000 cubic feet, but 



