142 ELECTRIC LIGHTING. 



A very interesting circumstance was discovered in the ex- 

 periments made by Jablochkoff, and that is, that the currents 

 supplied by the induction apparatus intended for the light 

 are most advantageously exerted by a magneto-electric gene- 

 rator giving alternately reversed currents, such as those 

 supplied by the Alliance Company or the Lontin Company. 

 With such a generator, the induction apparatus does not re- 

 quire either a condenser or an interrupter, and the intensity 

 of the current is increased by the suppression of these. On 

 the other hand the tension is notably diminished, for in ex- 

 periments I have witnessed, the spark was hardly 2 milli- 

 metres long ; but in order to obtain calorific effects, tension 

 is specially necessary, and we have seen that irrthis respect 

 the results have left nothing to be desired. Thanks to this 

 plan, a Ruhmkoff induction machine can supply the electric 

 light, and this result is of the more importance that a regu- 

 lator of the light is not required to render it steady, and that 

 the consumption of kaolin is almost insignificant (i milli- 

 metre per hour). The magneto-electric generator itself need 

 not be powerful, and it may, as we have already said, be pro- 

 portioned to the number of luminous jets desired, care being 

 taken to connect a suitable number of induction coils having 

 their induced wires not too thin. 



When the illumination ot a long strip of kaolin is required 

 under the influence of a very powerful current, it becomes 

 necessary in order to light it to mark a line of lead on the 

 upper edge of the bad conductor from one electrode to the 

 other. The current is at first conducted by this streak, but 

 is not long in heating the kaolin and in producing the effects 

 we have described. This arrangement enables a large quan- 

 tity of light to be obtained in a small space, for in order to 

 increase the effect it suffices to fold the strip several times on 

 itself like an electric multiplier. 



ance it meets in its passage, be accumulated within the very substance of the 

 bad conductor, and should be transformed into heat by not being able to 

 flow away fast enough as an electric charge. 



