WILLIAM SIEMENS, F.R.S. 245 



light appeared destined to take the place of all other lights for 

 that purpose. In dealing with light produced by the combustion 

 of oil or gas, they were necessarily limited to the amount to be 

 obtained under given conditions. A large amount of light could 

 be obtained by combustion, but it could not be concentrated 

 within the focus of a lamp. It was only by the electric current 

 that small surfaces could l)e heated to a point far exceeding the 

 tempi Tat ure attainable by combustion, and send out rays of light 

 second in energy only to those of the sun. It had been proved by 

 Ste.-Claire Deville, and Hunseu, that the utmost temperature to be 

 obtained by combustion was about 2,400 Cent., when a point was 

 reached at which combustion ceased and dissociation set in : and 

 therefore it was impossible to obtain rays of high intensity by 

 means of combustion. There were, no doubt, practical difficulties 

 to be overcome in applying the electric light to some situations 

 where power could not be easily raised ; but means of producing 

 power were continually being improved. Where you could not 

 raise steam you could decompose oil ; and where you could not 

 work a steam-engine you could use a gas-engine or an oil-engine, as 

 was already done in the United States to a large extent. With 

 the electric light also an admirable system of flashes of any desired 

 rapidity could be attained ; and he would conclude by expressing 

 a hope that they would soon attain the desired point when each 

 lighthouse would not only tell its own tale, but also give that 

 information to the greatest possible distance. 



In the discussion of the Paper 



"ON RECENT ADVANCES IN ELECTRIC LIGHTING," 

 By MR. W. H. PREECE, 



The CHAIRMAN (DR. C. W. SIEMENS),* in moving a vote of 

 thanks to Mr. Preece for his valuable paper, said that gentleman 

 had passed the whole subject of electric lighting in review, in a 



* Excerpt Journal of the Society of Arts, Vol. XXIX. 1880-81, p. 435, 436. 



