Figure 26. — Clarke's use of his magneto 

 generator to produce rotary motion (top) 

 and an arc between charcoal points (bottom). 

 From Annals of Electricity, January 1837, vol. 

 I, p. 154. 



Figure 27. — Davis' first version of Page's 

 magneto generator. From Charles Page, 

 "New Magnetic Electrical Machine . . . ," 

 American Journal of Science, July 1838, vol. 34, 

 p. 164. 



Figure 28. — Davis' improved version of Page's 

 magneto generator, shown here ringing a bell. 

 From D. Davis, Manual of Magnetism, Boston, 

 ed. 13, 1869, p. 281. 



current collectors were rollers that touched the 

 commutator bars; they were placed about 60° 

 apart, with their positions controlled by the speed of 

 rotation. 



In February 1857, Holmes suggested a possible 

 application for the new electric light system. While 

 considerable progress had been made during the 19th 

 century in increasing the safety of marine commerce, 

 the measures taken were still insufficient. Several 

 decades earlier the Fresnel lens system had been 

 added to the improved Carcel lamp, and new fuels 

 had been discovered that gave a brighter light; 

 although the efTectiveness of the lighthouses was 

 thereby increased, they were still inadequate. In 

 1867 the British Board of Trade reported that in 



one year 1,333 lives and 2,513 vessels were lost in 

 the inland and coastal waters of Great Britain.^* 



Holmes submitted his suggestion to Trinity House, 

 the agency responsible for lighthouses along the coast 

 of England, and proposed to the Elder Brethren 

 of the organization that the coinbination of arc-light 

 and magnetoelectric machines be used for lighthouses. 

 Although Faraday, who was the scientific advisor to 

 Trinity House at the time, had not been previously 

 convinced of the practicality of the electric light, 

 Holmes so persuaded him that, in May 1857, John 



3* A. G. Findlay, "On the Progress of the English Lighthouse 

 System," Journal oj the Society of Arts, 1858, vol. 6, pp. 238-249; 

 Cosmos, 1868, ser. 3, vol. 3, pp. 691-693. 



352 



BULLETIN 228: CONTRIBUTIONS FROM THE MUSEUM OF HISTORY AND TECHNOLOGY 



