THERMO-ELECTRIC GENERATORS. 45 



was put together in such a manner as to occupy less space, 

 was intended for the electric light exhibition at the Albert 

 Hall, London. The first form is 2*5 metres high and i 

 metre in diameter, the second 1*5 metre high and 80 centi- 

 metres wide. This last form, instead of being cylindrical, is 

 square, but it has the same electrical power, and is more 

 compact. 



The first form, represented in Fig. 6, comprises two dis- 

 tinct superposed piles, and the 

 furnace is below exactly as shown 

 in the figure. 



In each half of the apparatus 

 there are thirty rows of 100 ele- 

 ments, or 3,000 elements, making 

 in all for the two superposed ap- 

 paratus 6,000 elements. It is in 

 the outer faces of these rows that 

 the plates of copper which form 

 the dirTusers are fixed. 



Each part of this pile can 

 supply an electric light equal to 

 40 Carcel lamps. The total 

 electro-motive force is 218 volts, 

 or about 120 Bunsen cells; and 

 the total resistance is 31 ohms, 

 or 3,100 metres of telegraphic FlG< g 



wire.* This large pile requires, 

 as we already said, only 10 kilogrammes of coke per hour. 



In the apparatus intended for the English exhibition the 

 space is considerably reduced, and the rows of elements are 

 so arranged as to form four different piles, each giving a 

 current capable of producing a light equal to from 15 to 20 

 gas-jets. In this way four luminous centres are obtained 

 instead of two. 



* These determinations were made by Cabanellas, the manager of the 

 Electric Light agency. 



