ELECTRICAL ADVANCE IN THE PAST TEN YEARS. 129 



stations in our cities not only supply from the same mains, at the same 

 time, electric current which lights both arc and incandescent lamps 

 indiscriminately, but the system carries also a large load in electric 

 motors employed for such service as running elevators, driving venti- 

 lating fans, supplying power for pumping, and driving machinery in 

 shops of all kinds. The same mains supply cnrrent for charging stor- 

 age batteries, for heating metals for welding or workiug, for warming 

 rooms by electric heat, or for cooking by electric heaters. The physician 

 or surgeon draws upon the same system for current for the treatment 

 of disease, for galvano cautery, for electrolysis, and for the generation 

 of Eontgen rays. 



Another example is found in a modern war ship, which may embody 

 an electric plant for working its incandescent lights. The same machin- 

 ery supplies the search light, which is essentially an arc light of great 

 power. There are also electric cranes and hoists, turret- turning and 

 gun-training apparatus, motors for ventilating fans or for forced draft 

 in the boiler furnaces, all depending on the same suijply. 



Perhaps, however, no better examj)le of the varied application of 

 electric energy exists than at Niagara. Certainly no grander exempli- 

 fication of the way in which electric forces may be called into play, to 

 replace other and unlike agencies, can be cited. Here at Niagara we 

 may forcibly realize the importance of cheap and unfailing power devel- 

 oped from water in its fall. We find the power of huge water wheels 

 delivered to the massive dynanios for giving out electric energy. This 

 energy is variously employed. The electric lighting of the city of Niag- 

 ara and surroundings and the electric railways naturally depend uj)on 

 the water ]50wer. Besides these, which may be termed the ordinary 

 applications of electricity, there are clustered at Niagara a number of 

 unique industrial establishments, the importance of which will undoubt- 

 edly increase rapidly. In the carborundum factory we find huge 

 furnaces heated by the passage of electric current, and attaining temper- 

 atures far beyond those of the ordinary combustion of fuel. These elec- 

 tric furnaces produce carborundum, a new abrasive nearly as hard as the 

 diamond, which is a combination of carbon and silicon, unknown before 

 the electric furnace gave it birth. Sand and coke are the raw substances 

 for its production, and these are acted upon by the excessively high 

 heat necessary to form the new product, already in extensive use for 

 grinding hard materials. 



The metal aluminum, which not many years ago cost $2 an ounce, is 

 now produced on a large scale at Niagara, and sold at a price which 

 makes it, bulk for bulk, cheaper than brass. Here, again, electricity 

 is the agent; but in this case its power of electrolyzing or breaking up 

 strong chemical unions is employed. Great vats containing fused com- 

 pounds, such as fluorides of certain metals in which the aluminum ore 

 is dissolved, are arranged so that a powerful electric current sent 

 through the fused mass separates out the metallic aluminum. The 

 SM 97 9 



