50 FRAGMENTS OF SCIENCE 



Trinity House, determined to have the best available 

 apparatus, decided, in 1868, on the introduction of ma- 

 chines on the Alliance principle into the lighthouses at 

 Souter Point and the South Foreland. These machines 

 were constructed by Professor Holmes, and they still con- 

 tinue 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 experimental trial 

 at the South Foreland preceded the lighting of Dungeness 

 by more than two years. The electric light was afterward 

 established at Cape Grisnez. The light was started at 

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

 land on January 1, 1872. At the Lizard, which 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 

 transversely round cores of iron, as in the machine of 

 Saxton, Siemens, after giving a bar of iron the proper 

 shape, wound his wire longitudinally round it, and ob- 

 tained thereby greatly augmented effects between suitably 

 placed magnetic poles. Such an armature is employed in 

 the small magneto -electric machine which I now introduce 

 to your notice, and for which the Institution is indebted 

 to Mr. Henry Wilde, of Manchester. There are here six- 

 teen permanent horseshoe magnets placed parallel to each 



