Electricity as an Illuminant. 25 



the operation is continuous. The difficulty with the gas-engine 

 for generating currents is the irregularity of its motion. 



Mr. Greenhill — Gas-engines are made to give a practically 

 uniform and steady current, as I can prove. I am sorry to 

 interrupt the speaker, but I am bound to correct him in the 

 interest of the gas-engine manufacturers. 



Mr. Perry (continuing) — I am glad Mr. Greenhill has seen 

 one of these perfect gas-engines. He merely forestalls me by a 

 day or So. I was going to say T believe this difficulty will be 

 overcome in the near future. My authority as to gas-engines 

 is probably quite as valuable as that of Mr. Greenhill. The 

 standard book on gas-engines is one written by Professor 

 Robinson, of Nottingham, and that book in its preface, professes 

 to be an extension of my brother's lectures at the Finsbury 

 College. I wrote to my brother on this very point. Mr. 

 Greenhill appears to have information that my brother has not 

 yet, though he tells me that, for the present course of lectures 

 he is delivering, he has obtained from the manufacturers almost 

 every type of gas-engine. With gas-engines steady enough for 

 generating currents, we could produce electricity for lighting 

 purposes at a price which would compare with Mr. Preece's 

 price for electro-plating, because this would completely solve 

 the question of cheap storage. It is found in Crossley's place 

 that they are able to drive their gas-engines at o"8 of a penny 

 per indicated horse-power ; that is a price no steam-engine can 

 touch. I believe the age of gas will be succeeded by the 

 age of electricity, because in the best steam-engine we only 

 turn 5 per cent, of the energy of the coals into power ; but if 

 we could turn the energy of the coals into electrical energy 

 without the intervention of a steam-engine, then in my opinion 

 we should have a very great saving, and the age of electricity 

 would have dawned. 



Mr. J. M. Barbour — My experience is entirely confined to 

 electric lighting as used in spinning mills. There seems to be 

 a want of confidence with millowners at present in regard to 

 electric light. They seen to look upon it as a new idea : they 



