Two other young men from Ohio, Alfred and Eugene Cowles, with whom Hall was for a time associated, wore the first to develop the wide possibilities of the electric furnace on a commercial scale.  In 1885 they started the Cowles Electric Smelting and Aluminum Company at Lockport, New York, using Niagara power.  The various aluminum bronzes made by absorbing the electrolyzed aluminum in copper attracted immediate attention by their beauty and usefulness in electrical work and later the company turned out other products besides aluminum, such as calcium carbide, phosphorus, and carborundum.  They got carborundum as early as 1885 but miscalled it “crystallized silicon,” so its introduction was left to E.A.  Acheson, who was a graduate of Edison’s laboratory.  In 1891 he packed clay and charcoal into an iron bowl, connected it to a dynamo and stuck into the mixture an electric light carbon connected to the other pole of the dynamo.  When he pulled out the rod he found its end encrusted with glittering crystals of an unknown substance.  They were blue and black and iridescent, exceedingly hard and very beautiful.  He sold them at first by the carat at a rate that would amount to $560 a pound.  They were as well worth buying as diamond dust, but those who purchased them must have regretted it, for much finer crystals were soon on sale at ten cents a pound.  The mysterious substance turned out to be a compound of carbon and silicon, the simplest possible compound, one atom of each, CSi.  Acheson set up a factory at Niagara, where he made it in ten-ton batches.  The furnace consisted simply of a brick box fifteen feet long and seven feet wide and deep, with big carbon electrodes at the ends.  Between them was packed a mixture of coke to supply the carbon, sand to supply the silicon, sawdust to make the mass porous and salt to make it fusible.

[Illustration:  The first American electric furnace, constructed by Robert Hare of Philadelphia.  From “Chemistry in America,” by Edgar Fahs Smith]

The substance thus produced at Niagara Falls is known as “carborundum” south of the American-Canadian boundary and as “crystolon” north of this line, as “carbolon” by another firm, and as “silicon carbide” by chemists the world over.  Since it is next to the diamond in hardness it takes off metal faster than emery (aluminum oxide), using less power and wasting less heat in futile fireworks.  It is used for grindstones of all sizes, including those the dentist uses on your teeth.  It has revolutionized shop-practice, for articles can be ground into shape better and quicker than they can be cut.  What is more, the artificial abrasives do not injure the lungs of the operatives like sandstone.  The output of artificial abrasives in the United States and Canada for 1917 was: