6 Professor Tyndall [Jan. 17, 



discovery. The Elder Brethren of the Trinity House had had 

 the wisdom to make him their " Scientific Adviser ; " and it is 

 interesting to notice in his reports regarding the light the mixture 

 of enthusiasm and caution which characterized him. Enthusiasm was 

 with him a motive power, guided and controlled by a disciplined judg- 

 ment. He rode it as a charger, holding it in by a strong rein. 

 While dealing with Holmes, he states the case of the light pi-o and 

 con. He checks the ardour of the inventor, and, as regards cost, 

 rejecting sanguine estimates, he insists over and over again on the 

 necessity of continued experiment for the solution of this important 

 question. His matured opinion was however strongly in favour of the 

 light. With reference to an experiment made at the South Foreland 

 on the 20th of April, 1859, he thus expresses himself: — " The beauty 

 of the light was wonderful. At a mile off, the apparent streams of 

 light issuing from the lantern were twice as long as those from the 

 lower lighthouse, and apj^arently three or four times as bright. The 

 horizontal plane in which they chiefly took their way made all above 

 or below it black. The tops of the hills, the churches, and the houses 

 illuminated by it were striking in their effect upon the eye." Further 

 on in his report he expresses himself thus : — " In fulfilment of this 

 part of my duty, I beg to state that, in my ojiinion. Professor Holmes 

 has practically established the fitness and sufficiency of the magneto- 

 electric light for lighthouse purposes, so far as its nature and mauage- 

 ment are concerned. The light produced is powerful beyond any other 

 that I have yet seen so applied, and in principle may be accumulated to 

 any degree ; its regularity in the lantern is great ; its management 

 easy, and its care there may be confided to attentive keepers of the 

 ordinary degree of intellect and knowledge." Finally, as regards the 

 conduct of Professor Holmes during these memorable exj)eriments, it 

 is only fair to add the following remark with which Faraday closes the 

 report submitted to the Elder Brethren of the Trinity House on the 

 29th of Aju'il, 1859 :~"I must bear my testimony," he says, "to the 

 perfect openness, candour, and honour of Professor Holmes. He has 

 answered every question, concealed no weak point, explained every 

 applied principle, given every reason for a change either in this or 

 that direction, during several periods of close questioning, in a 

 manner that was very agreeable to me, whose duty it was to search 

 for real faults or possible objections, in respect both of the 2)resent 

 time and the future." 



Soon afterwards, the Elder Brethren of the Trinity House had the 

 intelligent courage to establisli the machines of Holmes permanently 

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

 for many years. 



The magneto-electric machine of the Alliance Company soon 

 succeeded to that of Holmes, being in various ways a very marked 

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

 was brighter tlum those of its 2)redecessor. In it, moreover, the 

 commutator, the flashing and destruction of which were sources of 



