C78 FRA GMENT8 OF SCIENCK. 



of the latter. In the de Meritens machine the commu- 

 tator 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 inventors 

 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 common junc- 

 tion 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 approach 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 has been given to M. Rapieff to develop and 

 simplify his invention at Printing House Square. The 

 illumination of the press-room, which I had the pleasure of 

 witnessing, under the guidance of M. Rapieff himself, is 

 extremely effectual and agreeable to the eye. There are, I 

 believe, five lamps in the same circuit, and the regulators 

 are so devised that the extinction of any lamp does not 

 compromise the action of the others. M. Rapieff has lately 

 improved his regulator. 



Many other inventors might here be named, and fresh 

 ones are daily crowding in. Mr. Werderrnann has been 

 long known in connection with this subject. Employing 

 as negative carbon a disc, and as positive carbon a rod, he 

 has, I am assured, obtained very satisfactory results. The 

 small resistances brought into play by his minute arcs 

 enable Mr. Werdermann to introduce a number of lamps 



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

 into beat and light, yielding about 1,900 candles; the large machine 

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



