ADDRESS. 11 



has now entered the lists in competition with compressed air, the 

 hydraulic accumulator, and the quick running rope as used at Schaff- 

 hausen to utilise the power of the Rhine fall. The transformation of 

 electrical into mechanical energy can be accomplished with no further 

 loss than is due to such incidental causes as friction and the heating of 

 wires ; these in a properly designed dynamo-electric machine do not exceed 

 ten per cent., as shown by Dr. John Hopkinson, and, judging from recent 

 experiments of my own, a still nearer approach to ultimate perfection is 

 attainable. Adhering, however, to Dr. Hopkinson's determination for 

 safety's sake, and assuming the same percentage in reconverting the 

 current into mechanical effect, a total loss of 19 per cent, results. To 

 this loss must be added that through electrical resistance in the connecting 

 line wires, which depends upon their length and conductivity, and that 

 due to heating by friction of the working parts of the machine. Taking 

 these as being equal to the internal losses incurred in the double pro- 

 cess of conversion, there remains a useful effect of 100 — 38 = 62 per 

 cent., attainable at a distance, which agrees with experimental results, 

 although in actual practice it would not be safe at present to expect more 

 than 50 per cent, of ultimate useful effect, to allow for all incidental losses. 



In using compressed air or water for the transmission of power, the 

 loss cannot be taken at less than 50 per cent., and, as it depends upon 

 fluid resistance, it increases with distance more rapidly than in the case of 

 electricity. Taking the loss of effect in all cases as 50 per cent., electric 

 transmission presents the advantage that an insulated wire does the work 

 of a pipo capable of withstanding high internal pressure, which latter 

 must be more costly to put down and to maintain. A second metallic 

 conductor is required, however, to complete the electrical circuit, as the 

 conducting power of the earth alone is found unreliable for passing 

 quantity currents, owing to the effects of polarization ; but as this second 

 conductor need not be insulated, water or gas pipes, railway metals 

 or fencing wire, may be called into requisition for this purpose. The 

 small space occupied by the electi-o-motor, its high working speed, 

 and the absence of waste products, render it specially available for the 

 general distribution of power to cranes and light machinery of every 

 description, A loss of effect of 50 per cent, does not stand in the way 

 of such applications, for it must be remembered that a powerful central 

 engine of best construction produces motive power with a consumption 

 of two pounds of coal per horse-power per hour, whereas small engines 

 distributed over a district would consume not less than five ; we thus 

 see that there is an advantage in favour of electric transmission as 

 regards fuel, independently of the saving of labour and other collateral 

 benefits, which more than compensate for interest on the cost of instal- 

 lation. 



To agriculture, electric transmission of power seems well adapted for 

 effecting the various operations of the farm and fields from one centre. 

 Having worked such a system myself in combination with electric lighting 



