Blectrical products Carborundum. 213 



ized mixture, with a core of broken coke elec- 

 trically connected at the ends. It is now 

 ready for the application of electricity, which 

 completes the work. 



Let us go back to the transformer-room and 

 examine the, electrical appliances that bring 

 the current down to a proper voltage to pro- 

 duce the heat necessary to cause a union be- 

 tween the silica of the sand and the carbon of 

 the coke, which results in the beautiful car- 

 borundum crystals that we have heretofore de- 

 scribed. 



The current is delivered from the Niagara 

 Power Company under a pressure of 2200 

 volts. The conductors run first into the trans- 

 former-room, which adjoins the furnace-room, 

 and is tln-rc transformed down from 2200 volts 

 to an average of about 200 volts. The trans- 

 formers at tho-c works have a capacity of 

 about 1100 horse-power. About 4 per cent 

 of this power is converted into heat in the 

 process of transformation, making a loss in 

 <l.rtrial energy of a little over 40 horse- 

 p. This heat would be sufficient to de- 

 stroy the trail-former if some arrangement 

 were not provided to carry it off. We have al- 

 ready described how thi- i< done through the 

 medium of a circulation of oil. Because of the 

 low voltage and enormous quantity of the cur- 

 rent pa--intr from the transformer to the fur- 

 nace very large conductors are required. The 



