APPARATUS FOR THE ELECTRIC LIGHT. 143 



According to Jablochkoff, the luminous intensity of these 

 different sources varies according to the arrangement and 

 dimensions of the coil, and the number of lights interposed 

 in the circuit of each coil. They may therefore be so arranged 

 as to supply light of different intensities from their minimum 

 light of i or 2 gas-jets up to a light equivalent to 15 jets. 



u In this system," says Jablocbkoff, " the method of distribution 

 of the circuits is in fact reduced to a central artery represented 

 by a series of anterior wires corresponding with the inducing 

 helices of the different coils, and with as many partial circuits as 

 there are coils ; these last circuits corresponding with the induced 

 wires of the coils, and ending separately at the different luminous 

 ioci which are to be maintained. Each of these foci is therefore 

 perfectly independent, and can be extinguished or lighted sepa- 

 rately. Under these conditions the distribution of the electricity 

 becomes very similar to that of gas, and I have been able to have 

 50 foci simultaneously illuminated with different intensities. 3 ' 



Jablochkoff has lately rendered more practical the system 

 we have just described by causing the current supplied by 

 the small pattern of the magneto-electric Alliance machine 

 to act directly. In order to impart more tension to the 

 "currents he adopts a condenser of rather large surface to one 

 of the wires going from the machine to each apparatus. This 

 condenser is composed of sheets of tinfoil, india-rubber, and 

 varnished silk, alternated and folded as in the English con- 

 densers for submarine cables. In this way, with a total con- 

 densing surface of 200 square metres, seven points of light 

 may be obtained instead of two, and what is more curious, 

 the increased effect is produced even with currents alter- 

 nately reversed. The arrangement of this system is besides 

 very simple ; one of the armatures of each condenser is con- 

 nected with one of the two wires of the machine, and the 

 second wire of this machine is connected with one of the 

 clips of each light apparatus, while the other clip corresponds 

 with the second armature of each condenser. There is then 

 produced within each condenser successive fluxes of each 



