772 REPORT — 1891. 



kaows of the hundreds of motors for small work which are supplied with electricity 

 by central stations in Boston and New Yurk, besides other places, and of the large 

 number of electric lifts supplied by the Otis Company with electric motors de- 

 signed by Eickmeyer. I will only place before English manufacturers two of the 

 establishments where a statement of what has been done is enough to bring con- 

 viction to the mind of every shrewd and sensible employer of power. In the great 

 works of AVilIiam Sellers & Co. shafting has been abolished as far as possible. 

 The second establishment is Baldwin's locomotive factory, whence from sixteen to 

 twenty locomotives are sent off every week, and where space is so far valuable 

 that there is no room for shunt lines, and where a 100-ton ti-avelling crane picks 

 up one out of the twenty, and puts it down where wanted. This fine travelling 

 crane, and every other crane in this huge part of the works, are driven by electric 

 motors. 



Tratismission of Power to a Distance from Waterfalls. — With regard to trans- 

 mission of power to a distance from waterfalls, I have seen little to chronicle in 

 America, and what there is seems rather antiquated ; but in Switzerland important 

 work has been done both by continuous and alternating currents. The high ten- 

 sion electrical work in connection with continuous currents that most impressed 

 me was what has been done by Cuenod. Sautter, et Cie. Their six-pole machines 

 with Gramme commutators up to 2,000 volts, designed by M. Thury, seem to 

 work admirably and sparklessly, and I must here state my conviction, which I did 

 not previously hold, that the insulation of such a machine can be made perfect, 

 as there done, by supporting the dynamo or motor on a number of alternate slabs 

 of vulcanised rubber and porcelain, and by connecting the shafts by Eafi'ard 

 couplings. 



I will not take up time with describing different works of this kind, but 1 will 

 now say something about the use of multiphase alternate, or rotary currents, about 

 the prospective use of which so much has been published. I have seen the machines 

 and transformers in course of construction at Oerlikon, and the insulators which 

 have been used ; the mechanical design is excellent. I can quite appreciate the 

 difficulties of regulation of three currents referred to by M. Dobrowolski, but I 

 think that there are further points upon which information is much wanted. I 

 want to know, for hitherto I have utterly failed to see, the advantage of this 

 three-phase synchronising alternator over the simple alternators which do such 

 excellent work. I have been told that calculation shows that Mr. Brown's machine 

 has 96 per cent, efficiency as a dynamo. AVell, I reply that an ordinary alternator 

 without iron, not having the hysteresis of Mr. Brown's machine, ought to have 

 a higher efficiency. In the next place I am told by Mi'. Brown that while you 

 cannot switch one of these three-phase synchronising motors, with its load, on to 

 an electric circuit, and expect it to get up to the synchronising speed, yet it will 

 do so along with the electric generator of electricity, if the latter be also started 

 from rest. In this it certainl}' has the advantage over the synchronising alternator 

 with iron, but none whatever over those without iron, which will act in precisely 

 the same Avay unless the motor happens to be stopped on dead centres, i.e. with 

 the centres of coils (in a Mcrdey alternator, for example) half way between the 

 poles of the field magnets. If this is the only gain over single-phase alternators 

 with self-induction, and if there be no advantage gained over alternators without 

 large self-induction, I fail to see the merit of the complication of three phases. I 

 would not have drawn attention to the absence of advantage, but would have 

 preferred to await the experiments before expressing an opinion, were it not for 

 the great attention directed to the scheme by the Press, altogether out of propor- 

 tion to the results which Mr. Brown and the Oei'likon managers hope to obtain. 

 The great experiment about to be tried at Frankfort, which interests electricians 

 all over the world, is not to prove that transformation is efficient, but to prove 

 that 30,000 volts can be carried along 112 miles of overhead conductor. 



M. Dobrowolski says that whatever load may be put on his motors, there is no 

 .serious difference in phase between the potential difJ'erence applied to the motor 

 and the current, and there is no appreciable lag. If this be so, it would be a de- 

 cided improvement ; but I shall require strong proof before I accept the multiphase 



