l8o THE ADDRESSES, LECTURES, ETC., OF 



Experiments have since been made with a view to ascertain the 

 percentage of power that may thus be utilized at a distance, and 

 the results of these experiments are decidedly favourable for such 

 an application of the electrical conductor. A small machine, 

 weighing 3 cwt. and entirely self-contained, was found to exert 

 2'3 horse-power as measured by a Prony's brake, with an expendi- 

 ture of five horse-power at the other end of the electric conductor, 

 thus proving that above 40 per cent, of the power expended at the 

 distant place may be recovered ; the 60 per cent, lost in trans- 

 mission includes the friction of both the dynamo- electric and 

 electro-motive engines, the resistance of the conductor, and the 

 loss of power sustained in effecting the double conversion. This 

 amount of loss seems considerable, and would be still greater if 

 the conductor through which the power were transmitted were of 

 great length and relatively greater resistance ; but on the other 

 hand it must be remembered that the power of a natural motor 

 is obtained without expenditure of coal, and that a small caloric 

 motor which the electric motor is intended to supplant is in- 

 convenient and very extravagant in fuel. The electric motor 

 presents moreover this great advantage, that it requires hardly 

 any installation, and would be available at any time by merely 

 closing the electric circuit without incurring the risk and in- 

 convenience inseparable from steam and gas engines. 



Without considering at present the utilization of natural forces, 

 let us take the case of simply distributing the power of a steam- 

 engine of say 100 horse-power to twenty stations, within a circle 

 of a mile diameter, for the production of both light and power. 

 The power of 100 horses can be produced with an expenditure 

 of 250 pounds of coal per hour, if the engine is constructed upon 



250 

 economical principles, or of -~TT = 12*5 Ibs. per station. In the 



case of the current being utilized for the production of light 2'3 

 x 1200 = 2760, or say 2,000 candle-power, are producible at the 

 station, whereas if power is desired 2 -3 horse-power may be 

 obtained, in both cases with the expenditure of 12 -5 pounds of 

 coal, representing a penny an hour for cost of fuel, taken at 

 fifteen shillings a ton. The size of the conductor necessary to 

 convey the effect produced at each station need not exceed half an 

 inch in external diameter, and its cost of establishment and main- 



