illll j lll ll -I — I — \ — (- 



i- ! f f r f T 



Figure 41. — Details of Alliance magneto generator, without commutator. From Bulletin de 

 la Societe d' Encouragement pour r Industrie Nationale, ser. 2, 1867, vol. 14, pi. 370 (facing p. 

 804). 



„,^-,,- . .. T-'-- -T-,.' .--T— — --■^---•- -n.--^ 



the machine as costing £100, as being 2 feet long, 1 

 foot 2 inches wide, and 2 feet high, and as weighing 

 360 pounds.''^ Actually, the results cited were overly- 

 sanguine on Fontaine's part — Tresca found that the 

 300-Carcel-unit dynamo required 2.8 hp. and the 

 1,850-Carcel-unit machine required 7.7 hp. This 

 would result in 107 and 240 Carcel units per horse- 

 power, which still seems quite high. 



The central testing depot of the French lighthouse 

 administration carried out similar tests of the Alliance, 

 De Meritens, and Gramme machines during the 

 years 1880-1882.'* As can be seen from the following 



'3 Engineering, 1877, vol. 24, p. 322 (see also letter from 

 Charles Ball, p. 348); Henri E. Tresca, "Compte rendu des 

 experiences faites pour la determination du travail depense 

 par les machines magneto-electrique de M. Gramme, employees 

 pour produire de la lumiere dans les ateliers de MM. Sautter 

 ct Lcmonnier," Camples rendus, 1876, vol. 82, pp. 299-305. 



'< .\llard, op. cit. (footnote 47), pp. 339-348. 



Figure 42. — Alliance generator being used to 

 drive an arc light. From Bulletin de la Societe 

 d' Encouragement pour F Industrie Nationale, ser. 2, 

 1867, vol. 14, fig. 16 (p. 692). 



368 



BULLETIN 228: CONTRIBUTIONS FROM THE MUSEUM OF HISTORY AND TECHNOLOGY 



