Figure 6. — Staite's arc-light regulator of 1853. 

 In tliis modification of his invention Staite 

 used the upward buoyancy of the float {bb) 

 to balance the downward pull of the coil of 

 the solenoid {D). From J. Dredge, Electric 

 Illumination, London, n.d. (about 1882), vol. 

 I, p. 389. 



and irregular in its action.^ However, this regulator 

 seemed so promising that after Archereau demon- 

 strated it in a St. Petersburg square Czar Nicholas 

 requested the Russian Academy of Sciences to in- 

 vestigate streetlighting by this method.^" Then, in 

 1855, Archereau sought to illuminate the port of 

 Marseilles with his arc lamp." 



In 1850 Duboscq simplified Foucault's regulator 

 to the extent that it became sufficiently reliable for 

 regular use in the theater as well as for laboratory 

 and lecture demonstrations (figs. 11, 12). The use of 

 the brilliant arc light became so necessary for spec- 

 tacular effects that finally, in 1855, an entire rootn 

 at the Paris Opera House was set aside for Duboscq's 

 electrical equipment. The prizes at the Exposition 

 Universelle of Paris in 1855 were handed out in the 

 brilliance of this regulator, with one of the awards 

 going to Duboscq for his invention; other prizes and 

 honors followed successive improvements in the reg- 

 ulator.'- However, the regulator was still too delicate, 

 and there was a disadvantage in that the clockwork 

 required winding. 



Except for Staite's lamp, these early regulators 

 were satisfactory only for a relatively short period of 



9 British patent 7924 (February 12, 1849); Du Moncel, 

 op. cit. (footnote 5). 



^0 Illustrated London News, December 1, 1849, vol. 15, p. 362. 



11 Les Mondes, 1863, vol. 2, p. 452. 



12 Jules Duboscq, "Note sur un regulateur electrique," 

 Comptes rendits, 1850, vol. 31, pp. 807-809; Edmond Becquerel, 

 "Rapport ... sur I'appareil photo-electrique de M. Jules 

 Duboscq, opticien," Bulletin de la Societe d' Encouragement pour 

 I' Industrie Nationale, 1855, ser. 2, vol. 2, pp. 455-461; Hippolyte 

 Fontaine, Eclairage a V electricite, Paris, 1877, p. 11; La Lumiere 

 electrique, 1880, vol. 2, pp. 284-288; Cosmos, 1855, vol. 7, pp. 

 492-494; 1864, vol. 24, pp. 121-126; Du Moncel, op. cit. 

 (footnote 5), vol. 3, pp. 221-231, 280; L'.innee .^cientifique, 

 1856, vol. 1, pp. 485-486; Mechanics Magazine, 1857, vol. 67, 

 p. 250; 1858, vol. 68, pp. 252-253; Jules A. Lissajou, in Bulletin 

 de la Societe d' Encouragement pour I' Industrie Rationale, 1859, ser. 

 2, vol. 6, p. 254. 



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