ELECTRIC LIGHTING. 131 



Comparing electric with gas lighting, the hopeful believers 

 in progressive improvement appear to forget that gas-making 

 and gas-lighting are as susceptible of further improvement as 

 electric lighting, and that, as a matter of fact, its practical prog- 

 ress during the last forty years is incomparably greater than 

 that of the electric light. I refer more particularly to the 

 practical and crucial question of economy. The by-products, 

 the ammoniacal salts, the liquid hydrocarbons, and their 

 derivatives, have been developed into so many useful forms by 

 the achievements of modern chemistry that these, with the 

 coke, are of sufficient value to cover the whole cost of manu- 

 facture, and leave the gas itself as a volatile residuum that costs 

 nothing. It would actually and practically cost nothing, and 

 might be profitably delivered to the burners of gas consumers 

 (of far better quality than now supplied in London) at one 

 shilling per thousand cubic feet, if gas- making were conduted 

 on sound commercial principles that is, if it were not a corpo- 

 rate monopoly, and were subject to the wholesome stimulating 

 influence of free competition and private enterprise. As it is, 

 our gas and the price we pay for it are absurdities ; and all 

 calculations respecting the comparative cost of new methods of 

 illumination should be based not on what we do pay per candle- 

 power of gas-light, but what we ought to pay and should pay 

 if the gas companies were subjected to desirable competition, 

 or visited with the national coniiscation I consider they deserve. 



Having had considerable practical experience in the commer- 

 cial distillation of coal for the sake of its liquid and solid 

 hydrocarbons, I speak thus plainly and with full confidence. 



There is yet another consideration, and one of vital impor- 

 tance, to be taken into account viz. that, whether we use the 

 electric light derived from a dynamo-electric source, or coal- 

 gas, our primary source of illuminating power is coal, or 

 rather the chemical energy derivable from the combination of 

 its hydrogen and carbon with oxygen. Now this chemical 

 energy is a limited quantity, and the progress of Science can 

 no more increase this quantity than it can make a ton of coal 

 weigh 21 cvvts. by increasing the quantity of its gravitating 

 energy. 



The demonstrable limit of scientific possibilities is the eco- 

 nomical application of this limited store of energy, by convert- 

 ing it into the demanded form of force without waste. The 

 more indirect and roundabout the method of application, the 

 greater must be the loss of power in the course of its transfer 



