84 ELECTROLYSIS. 



francs, which price corresponds to 74 centimes per watt, 

 admitting, as in the case of the Weston machine, an efficiency 

 of 70 per cent. 



This calculation establishes the fact that the price of 

 dynamos is higher in America than in Europe. 



ELMORE MACHINE. The Elmore machine (Fig. 18) has a 

 great resemblance to the Weston; it possesses six electro- 

 magnets revolving in front of the poles of six stationary 



FIG. 18. 



Elmore Machine. 



electro-magnets and an external commutator. Only, in the 

 Elmore machine, the two series of electro-magnets are parallel 

 instead of being normal to each other, and each electro- 

 magnet is composed of two coils instead of one ; this is enough 

 to constitute an original type of machine in the domain of 

 electricity. 



The Elmore machine is, besides, possessed of a particularity 

 which is worth noticing ; we refer to the cooling arrangement 

 for preventing any part of the machine becoming overheated. 

 To effect this the spindle of the machine is made hollow, as 

 well as the cores of all the coils, and by means of a system of 

 injection pipes water or cold air may be made to circulate 



