596 



SCIENTIFIC NEWS. 



[Oct. 12, i5 



not to be superficial, yet I must not tease your under- 

 standing, and so we will not lose ourselves in technical 

 details. If, however, my remarks have led you to appre- 

 ciate the vast economical importance of using very large 

 electric pressures, and to grasp that by substituting 

 2,000 volts for 50 volts when transmitting a certain 

 amount of electric power the current can be reduced to 

 one-fortieth part, and the waste of power when trans- 

 mitted along a given length of a given wire to the 

 i-4oth of the i-40th, that is to the i-i6ooth part, your 

 imagination will have been kindled as well as amused. 



With a loss on the road of only 1 1 per cent. M. Deprez 

 has, by using 6,000 volts, transmitted 52-horse power over 

 a distance of about thirty-seven miles through a copper 

 wire only i-6th of an inch in diameter. A piece of the 

 actual conductor he employed I hold in my hand ; the 

 copper wire is coated with an insulated material, and then 

 with a leaden tubing, so that the outside may be touched 

 with perfect impunity, in spite of the high potential 

 difference employed. M. Deprez's dynamo and motor 

 were not nearly as efficient as he could make them now, 

 so that his terminal losses were unnecessarily great, and 

 the efficiency of the whole arrangement, wonderful as it 

 was, was not so startling as it would otherwise have 

 been. I have told you that the loss in dynamo and 

 motor has actually been reduced to only 12A per cent., 

 so that if a dynamo and motor of this efficiency had been 

 used by M. Deprez the total loss in the whole trans- 

 mission over thirty-seven miles would have been under 

 25 per cent. Indeed, by using only 1,250 volts Mr. 

 Brown has succeeded in transmitting 50-horse power 

 supplied by falling water at Kriegstetten to Solothun in 

 Switzerland, five miles away, with an entire loss in the 

 dynamo, motor, and the five miles of going and returning 

 wire of only 25 per cent., so that | of the total power 

 supplied by the water at Kriegstetten was actually 

 delivered to machinery at Solothun, five miles away. 



In less than twenty years then from Gramme's prac- 

 tical realisation of Pacinotti's invention we have power 

 transmitted over considerable distances by electricity 

 with only a total loss of 25 per cent., whereas the com- 

 bined loss in an air pump and air motor, or in a water- 

 pump and water motor is 40 per cent., irrespective of 

 the additional loss by friction or leakage that occurs en 

 route. We cannot help feeling that we are rapidly 

 arriving at a new era, and that it will not merely be for 

 the inauguration of the quick transmission of our bodies 

 by steam, or the quick transmission of our thought by 

 telegraph, but for the economical transmission of 

 power by electricity, that the Victorian age will be 

 remembered. 



I showed you a little while ago an electric fire. Was 

 that a mere toy, or had it any commercial importance ? 

 To burn coal, to work dynamos, and to use the electric 

 current to light your houses and your streets is clean and 

 commercial ; to use the current to warm your rooms clean 

 but wasteful, on account of the inefficiency of the steam 

 engine. But when the dynamos are turned by water 

 power which would otherwise be wasted, the electric 

 current may be economically used not merely to give 

 light, but also to give heat. And when the electric 

 transmission of power becomes still more perfect than at 

 present, even to burn coal at the pit's mouth, where it 

 is worth a shilling a ton, may, in spite of the efficiency 

 of the steam-engine being only one-tenth, be the most 

 economical way of warming distant towns where coal 

 would cost twenty shillings a ton. Think what that 



would mean, no smoke, no dust, a reform effected com- 

 mercially which the laws of the land on smoke prevention 

 are powerless to bring about, a reform effected without 

 the intervention of the State, and, therefore, dear to the 

 hearts of Englishmen. 



I am aware that this idea of burning coal at the pit's 

 mouth and electrically transmitting its power has quite 

 recently been stated to be commercially impracticable. 

 But is that quite so certain ? for in 1878 it was stated that, 

 although telephones may do very well for America, they 

 certainly would never be introduced into Great Britain, as 

 we had plenty of boys who were willing to act as mes- 

 sengers for a few shillings a week. The phonograph 

 was also declared to be worked by a ventriloquist, and 

 electric lighting on a large scale was proved to be too 

 expensive a luxury to be ever carried out. 



To-day the electric current is used for countless pur- 

 poses ; not only is it used to weld, but by putting the 

 electric arc inside a closed crucible, smelting can be 

 effected with a rapidity and ease quite unobtainable with 

 the ordinary method of putting the fire outside the cru- 

 cible. If one had pointed out a few years ago that it was 

 as depressing scientifically to put a fire outside a crucible 

 when you wanted to warm the inside, as Joey Ladle, the 

 cellarman, found it depressing, mentally, " To take in the 

 wine through the pores of the skin instead of by thecon- 

 wivial channel of the throttle," who would have be- 

 lieved that, in 1888, a 500-horse power dynamo would 

 be actually employed to produce an eletcric arc inside a 

 closed crucible in the manufacture of aluminium bronze ? 

 Putting a conservative drag on the wheels is a good pre- 

 caution to take when going downhill, but it is out of place 

 in the uphill work of progress. 



But of all the many commercial uses to which the 

 electric current may be put, probably, after the electric 

 light, electric traction has most public interest. The 

 English are a commercial people, but they are also a 

 humane people, and when, as in this case, their pockets 

 and their feelings are alike touched, surely they will be 

 radicals in welcoming electric traction, whatever may be 

 their political sentiments on other burning topics of the 

 day. It is not a nice thing to feel that you are helping 

 to reduce the life of a pair of poor tramway horses to 

 three or four years ; it would be a very nice thing to be 

 carried in a tramcar for even less fare than at present. 

 Now, while it costs 6d. or 7d. to run a car one mile with 

 horses, it only costs 3d. or 4d. to propel it electrically. 

 Indeed, from the very minute details that have recently 

 been published of the four months' expenses of elec- 

 trically propelling thirty cars at seven and a half miles 

 an hour along twelve miles of tramway line in Richmond, 

 Virginia, it would appear that the total cost, inclusive of 

 coal, oil, water, engineers, firemen, electricians, mechani- 

 cians, dynamo and motor repairers, inspectors, linemen, 

 cleaners, lighting, depreciation on engine, boiler, cars, 

 dynamos, and line work has been only i|d. per car per 

 mile. This tramway is no doubt particularly favourable 

 for propelling cars on the parallel system (that is the 

 system in which the current produced by the dynamo is 

 the sum of the currents going through all the motors on 

 the cars) without a great waste of power being produced 

 by a very large current having to be sent a very long 

 distance, because the tramway track is very curved and 

 the dynamo is placed at the centre of the curve jvith 

 feeding wires to convey the current from the dynamo to 

 all parts of the tra:k. But even in the case of a straight 

 tramway line with a dynamo only at one end, it is quite 



