176 



tens was tested at the Royarinstitution 

 by Dr. Tyndall and himself, and one was 

 purchased by the Trinity House in 1880, 

 and sent to the Lizard lighthouses, where 

 it had been in successful operation every 

 night since that date, giving no more 

 trouble than the original alternate-cur- 

 rent machines of the Alliance Company 

 and Holmes. Three of these machines 

 of larger size, giving currents of about 

 160 amperes and 42 volts, were purchased 

 by the Trinity House, and used at the 

 trials, at the South Foreland, in 1884-85, 

 into the relative merits of electricity, gas, 

 and mineral oil as lighthouse illuminants. 

 These machines gave great satisfaction, 

 and two of them had since been perma- 

 nently installed at St. Catharine's light- 

 house. 



Mr. G. Kapp, in reply, said he had 

 first thought that his paper was more 

 scientific than it should have been, but 

 the discussion had beaten him completely 

 in the amount of science which had been 

 developed. Considerable importance 

 seemed to have been attached to the 



