\/A' WILLIAM SIEMENS, /-\R.S. 199 



a steel magnet ; and, small as it appeared, it was the origin of a 

 iv solution in the applied arts. The effects obtained by the 

 r\l>'Timent were very small, and it was not until Pixii, in 1883, 

 constructed an electro-magnetic machine, which was soon after 

 impruvi-d upon by Clarke, that a continuous succession of electric 

 sparks or currents was obtained by means of a permanent magnet. 

 This was taken advantage of by Professor Holmes, in 1856, when 

 he constructed his celebrated magneto-electric machine, which 

 was still used for illuminating many lighthouses in France and 

 elsewhere. The next important step was the invention or discovery 

 of dynamo-electric currents, which was claimed by several men of 

 science. Professor Wheatstone and himself had brought papers 

 before the Royal Society at the same time, and his brother had 

 brought one before the Berlin Society somewhat earlier. No 

 doubt, as often happened, the same idea occurred to them all. 

 Mr. Varley, although he did not publish what he had done until 

 lately, had also worked in the same direction. With the dynamo- 

 electric machine they had the power of magnetism developing a 

 current, turning mechanical energy into electrical energy, without 

 much loss, for the loss in converting energy into current was not 

 more than 30 per cent. ; this was less than the result obtained in 

 any other mechanical conversion. With this power, therefore, 

 they had an engine which converted mechanical force into electrical 

 force, and that electrical force into light, by a process which was 

 now perfectly well understood. There remained, however the 

 further question to be solved : Given the power of the light, how 

 could it be put in such form as to be suitable for the purposes of 

 mankind ? The room was at present lighted by one of his own 

 electric lamps, worked by his machine. He was sorry to say 

 that it had not always been steady ; but this want of steadiness 

 was not the fault of the lamp. If the motive force had been 

 uniform, the light would have been uniform ; and he had just 

 been informed that at the time when a considerable alteration 

 took place, the steam in the little engine used to drive the machine 

 had fallen from 70 Ibs. pressure to f>f> Ibs., and the dynamo- 

 machine was brought almost to a standstill. It was always a 

 difficulty, in temporary arrangements, to maintain steam at any- 

 thing like a steady pressure, and hitches always occurred in getting 

 up hurried experiments. There was, however, a more serious 



