428 FRAGMENTS OF SCIENCE. 



tirely abandoned; alternating currents instead of the 

 direct current being employed. M. Serrin modified his 

 excellent lamp with the express view of enabling it to 

 cope with alternating currents. During the Interna- 

 tional Exhibition of 1862, where the machine was 

 shown, M. Berlioz offered to dispose of the invention to 

 the Elder Brethren of the Trinity House. They re- 

 ferred the matter to Faraday, and he replied as fol- 

 lows: ' I am not aware that the Trinity House authori- 

 ties have advanced so far as to be able to decide whether 

 they will require more magneto-electric machines, or 

 whether, if they should require them, they see reason to 

 suppose the means of their supply in this country, from 

 the source already open to them, would not be suffi- 

 cient. Therefore I do not see that at present they want 

 to purchase a machine.' Faraday was obviously swayed 

 by the desire to protect the interests of Holmes, who 

 had borne the burden and heat which fall upon the 

 pioneer. The Alliance machines were introduced with 

 success at Cape la Heve, near Havre; and the Elder 

 Brethren of the Trinity House, determined to have the 

 best available apparatus, decided, in 1868, on the intro- 

 duction of machines on the Alliance principle into the 

 lighthouses at Souter Point and the South Foreland. 

 These machines were constructed by Professor Holmes, 

 and they still continue in operation. With regard, 

 then, to the application of electricity to lighthouse pur- ' 

 poses, the course of events was this: The Dungeness 

 light was introduced on January 31, 1862; the light at 

 La Heve on December 26, 1863, or nearly two years 

 later. But Faraday's experimental trial at the South 

 Foreland preceded the lighting of Dungeness by more 

 than two years. The electric light was afterwards es- 

 tablished at Cape Grisnez. The light was started at 

 Souter Point on January 11, 1871; and at the South 



