NATURE 



97 



THURSDAY, NOVEMBER 29, iS 



SCIENTIFIC WORTHIES 



XXIII.— Sir Charles William Siemens,' Born 

 April 4, 1823; Died November ig, 1SS3 



THE death of Sir William Siemens, coming as it did 

 so suddenly and unexpectedly, has been felt as a 

 severe blow and grief through a far wider circle than that 

 of his personal friends. His work for the last five or six 

 years has interested the general public to a degree that 

 has perhaps never before been the lot of any man devoted 

 to science as he has been. Not only the people of his 

 adopted country, England, but the larger public of the 

 whole civilised world, have been deeply interested in the 

 electric lighting, the electric transmission of power, the 

 electric railways, the regenerative gas furnaces, and the 

 conversion of fuel into gas to feed them, and the pros- 

 pect of smoke abatement by this mode of dealing with 

 coal, and the improvements it has helped to make in the 

 manufacture of steel, in all of which they have recog- 

 nised Sir William Siemens as an originator, a devoted 

 worker, and a friend. The Portrush and Bushmills 

 electric tramway in the north of Ireland, one of the most 

 splendid and interesting of his achievements, now carries 

 passengers on a six and a half miles line of steep gradients 

 and sharp curves, at a good ten miles an hour, solely by 

 water power of the River Bush, driving, through turbines, 

 a 250 volt Siemens dynamo at a distance of seven and a 

 half miles from the Portrush end of the line. Just two 

 months before his death he was present, and the writer 

 of this article had the great pleasure of being present with 

 him, at the formal opening to the public by the Lord- 

 Lieutenant of Ireland, Earl Spencer, of this transcendent 

 gift of science to mankind. His death is mourned as an 

 irreparable loss, and the thought that advances in so many 

 lines of beneficent progress, carried on by his untiring 

 activity and his splendid zeal, are so suddenly stopped 

 has caused most grievous disappointment. 



William Siemens had the great characteristic common 

 to all men who have left their mark on the world, the 

 perferviclitDi iiigenium, in which thought leads to instant 

 action. When he was only twenty years old he came to 

 England with his brother Werner, to realise an invention 

 for electro-gilding ; and, persevering through the com- 

 plication of difficulties naturally met with by young men 

 in a strange land, with little knowledge of its language, 

 they succeeded in proving the usefulness of their inven- 

 tion, and getting it carried into practical effect through 

 the wise and kindly appreciation of Mr. Elkington. 

 Encouraged by this success, WiUiam Siemens returned a 

 year later with his chronometric governor, an invention 

 of remarkable beauty and ingenuity, in which, by the 

 motion of a pivoted framework carrying an idle wheel 

 geared to bevel wheels on two shafts in line, or geared to 

 the outer and inner circumferences of concentric wheels, 

 rotating in opposite directions on coaxial shafts, the move- 

 ment of one wheel is caused to keep time with that of the 

 other. We believe that although the invention was not 



* The Stetl Engraving, which was put in hand some time ago while the 

 life which has now passed away was rich in promise as well as 

 is not yet finished. It will be issued with a future number. — E 



Vol. XXIX. — No. 735 



a commercial success, and is not generally known in this 

 country as practically realised except in its application to 

 regulate the motions of chronoscopic instruments in the 

 Royal Observatory of Greenwich, it may yet be destined 

 to have large practical applications in engineering. 



One of William Siemens's early inventions was his water- 

 meter, which exactly met an important practical require- 

 ment, and has had a splendid thirty years' success. It 

 realised curiously subtle hydraulic principles, which, even 

 irrespectively of the practical value of the instrument, 

 may interest readers of N.ATURE. Imagine a Barker's 

 mill running absolutely unresisted. The discharged water 

 must have approximately zero absolute velocity on leaving 

 the nozzles ; in other words, its velocity relatively to the 

 nozzles must be approximately equal to the contrary 

 absolute velocity of the nozzles. Hence the machine will 

 rotate in simple proportion to the quantity of water 

 passing through it. By an extension of similar considera- 

 tions it is easy to prove that if the wheel, instead of being 

 unresisted, is resisted by a force exactly proportional to 

 the square of its angular velocity, its velocity must still 

 be proportional to the quantity of water passing through 

 it per unit of time. Thus, provided this law of resistance 

 is maintained, the whole angle turned through by the 

 wheel measures the whole quantity of water that has 

 passed. Now think of the difficulties which Siemens had 

 to overcome to realise this principle. What we have 

 roughly called a Barker's mill must be completely in- 

 closed in the supply water-pipes, its nozzles discharging 

 into water, not into air. It must be of very small dimensions 

 to be convenient for practice, and its bearings must be kept 

 oiled to secure, not only that it may not be injured by the 

 wear of running for years, but also that the constant 

 frictional force of solid rubbing on solid may be as 

 nothing compared to the resistance, proportional to the 

 square of the velocity, exerted by the circumambient 

 liquid upon a wheel with sharp edged vanes rotating in it. 

 After a few years of trials, difiiculty after difficulty was 

 overcome, and the instrument did its work with the 

 accuracy and convenience which met practical require- 

 ments. It was we believe the protection offered by the 

 British Patent Law, which, in the case of this very instru- 

 ment, allowed Siemens to work it out in England, and 

 so helped him eventually to find his home among us, and 

 to give us primarily the benefit of his great inventiveness 

 in all directions ; while the want of similar protection 

 under German law at that time rendered it practically 

 impossible for him to work out so difficult an inventio 1 

 in his own country. 



In electric invention William Siemens has been asso- 

 ciated with his brother Werner, and the world has profited 

 largely by this brotherly cooperation of genius. More 

 than a quarter of a century ago, they brought out what is 

 now known as the Siemens armature. The writer well 

 remembers admiring it greatly when he first saw it (he 

 believes at the London Exhibition of 1862), mounted 

 between the poles of a multiple steel horseshoe magnet 

 and serving for the transmitter in an electric telegraph. 

 That was what we may now call the one-coil Siemens 

 armature. It suggested inevitably the mounting of two 

 or more coils on the same iron core, in meridional planes 

 at equal angles round the axis, and as nearly equal and 

 similar in all respects as is allowed by the exigencies of 



