175 



efficiently ever since, and without a single 

 failure or the necessity for any repair. 

 In 1877, the Trinity House made a series 

 of competitive trials at the South Fore- 

 land, with the Holmes and Alliance alter- 

 nating, and the more powerful direct-cur- 



Fig. 38 



Mordey- Victoria Alternator. Open Circuit Curve 

 op Induction, Half Period. The dotted line 

 18 a sine-ccrve. 



rent machines of Gramme and Siemens, 

 which resulted in the adoption of the 

 Siemens machines for the two Lizard 

 lighthouses in 1878. In 1879, the alter- 

 nate-current machine of Baron de Meri- 



