Vlll 



different portions of wire laid over one another, and bent to one side 

 or the other, to avoid passing through the space occupied by the 

 bearing shaft. The principle of electro-magnetic augmentation and 

 maintenance of a current without the aid of steel or other permanent 

 magnets, invented by Werner Siemens, and also independently by 

 Wheatstone and S. A. Varley, was communicated to the Royal 

 Society by William Siemens on February 14, 1867, in his celebrated 

 paper on the " Conversion of Dynamical into Electric Force without 

 the aid of Permanent Magnets." This paper is peculiarly interesting, 

 as being the first scientific enunciation of that wonderful electro- 

 magnetic principle, on which are founded the dynamo-electric 

 machines of the present day. Soon after came the Paccinotti- 

 Gramme ring, from which followed naturally the suggestion of the 

 mode of connexion between the coils of a multiple-coil Siemens 

 armature, described in the Siemens-Alteneck patent of 1873, and 

 made the foundation of the Siemens dynamo as we now have it, 

 whether as constructed by the Siemens firm, or with the modifications 

 of details and proportions, valuable for many practical purposes, 

 which have been contributed by Edison and Hopkinson. The 

 evolution of the Siemens armature, as we now have it, in this splendid 

 machine, from the rudimentary type which the writer saw a quarter 

 of a century ago, is one of the most beautiful products of development 

 by inventive genius, and is more like to the growth of a flower than 

 to almost anything in the way of mechanism made by man. 



It is unnecessary here to enter upon the consideration of the many 

 new forms of apparatus for electric lighting given to the public by 

 the Siemens firm, but we may perhaps mention the highly successful 

 Siemens arc-lamp, and the various measuring instruments, particu- 

 larly the Watt meter ; this instrument being the realisation of a mode 

 of estimating electrical energy or activity by a new unit the " Watt " 

 suggested by Siemens in his Presidential Address to the British 

 Association at Southampton in 1882. He at the same time suggested 

 the " Joule " as a unit of heat or work, both of which units were at 

 once adopted by electrical engineers as convenient practical units. 



Just two months before his death Siemens witnessed the successful 

 completion and formal opening for traffic of the Portrnsh and Bush- 

 mills electric tramway, one of the most splendid and interesting of 

 his achievements. This railway, which is situated in the north of 

 Ireland, and was the first of its kind in this country, now carries 

 passengers on a 6-iniles line of steep gradients and sharp curves, at a 

 good 10 miles an hour, solely by water-power of the River Bush, 

 driving, through turbines, a 250-volt Siemens dynamo at a distance of 

 7 miles from the Portrnsh end of the line. 



We have seen how much the labours of William Siemens have 

 contributed to make electricity subservient to the wants of mankind, 



