THE ELECTRIC LIGHT. 441 



upon the principle of the magneto-electric machine, 

 employing permanent magnets as the exciters of the 

 induced currents. Using the magnets of the Alliance 

 Company, by a skilful disposition of his bobbins, M. de 

 Meritens produces with eight magnets a light equal to 

 that produced by forty magnets in the Alliance ma- 

 chines. While the space occupied is only one-fifth, the 

 cost is little more than one-fourth of the latter. In the 

 de Meritens machine the commutator is abolished. The 

 internal heat is hardly sensible, and the absorption of 

 power, in relation to the effects produced, is small. 

 With his larger machines M. de Meritens maintains a 

 considerable number of lights in the same circuit.* 



In relation to this subject, inventors fall into two 

 classes, the contrivers of regulators and the constructors 

 of machines. M. Rapieff has hitherto belonged to in- 

 ventors of the first class, but I have reason to know that 

 he is engaged on a machine which, when complete, will 

 place him in the other class also. Instead of two single 

 carbon rods, M. Rapieff employs two pairs of rods, each 

 pair forming a V. The light is produced at the com- 

 mon junction of the four carbons. The device for 

 regulating the light is of the simplest character. At 

 the bottom of the stand which supports the carbons are 

 two small electro-magnets. One of them, when the 

 current passes, draws the carbons together, and in so 

 doing throws itself out of circuit, leaving the control of 

 the light to the other. The carbons are caused to ap- 

 proach each other by a descending weight, which acts 

 in conjunction with the electro-magnet. Through the 

 liberality of the proprietors of the Times, every facility 



* The small machine transforms one-and-a-quarter horse-power 

 into heat and light, yielding about 1,900 candles; the large ma- 

 chine transforms five-horse power, yielding about 9,000 candles. 



