558 THE POPULAR SCIENCE MONTHLY. 



Dungeness, where the magneto-electric light continued to shine for 

 many years. 



The magneto-electric machine of the Alliance Company soon suc- 

 ceeded that of Holmes, and was in various ways a very marked im- 

 provement on the latter. Its currents were stronger and its light 

 brighter than those of its predecessor. In it, moreover, the comaiu- 

 tator, the flashing and destruction of which were sources of irrregu- 

 larity and deterioration in the machine of Holmes, was, at the sugges- 

 tion of M. Masson,' entirely 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 cur- 

 rents. During the International 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 referred the matter to Faraday, 

 and he replied as follows : " I am not aware that the Trinity House 

 authorities 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 introduction of machines on the Alliance principle into 

 the lighthouses at Souter Point and the South Foreland. These ma- 

 chines were constructed by Professor Holmes, and they still continue 

 in operation. With regard, then, to the application of electricity to 

 lighthouse purposes, 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 experi- 

 mental trial at the South Foreland preceded the lighting of Dungeness 

 by more than two years. The electric light was afterward established 

 at Cape Grinez. The light was started at Souter Point on January 11, 

 1871 ; and at the South Foreland on January 1, 1872. At the Lizard, 

 which probably enjoys the newest and most powerful development of 

 the electric light, it began to shine on January 1, 1878. 



I have now to revert to a point of apparently small moment, but 

 which really constitutes an important step in the development of this 

 subject. I refer to the form given in 1857 to the rotating armature by 

 Dr. Werner Siemens, of Berlin, Instead of employing coils wound trans- 

 versely round cores of iron, as in the machine of Saxton, Siemens, after 

 giving a bar of iron the proper shape, wound his wire longitudinally 

 1 Du Moncel, " L'^lectricite," August, IS'ZS, p. 150. 



