Carborundum

Among the industries supplied with electrical power by Niágara Falls is the manufacture oí carborundum crystals. These are iormed by tho reduction in ekctric furnaces of a mixture of sand, coke, salt and sawduat. The beautiful l)lue crystals are afterwards crushed to powder, which is uaed as an abraaive, llke emery or corundum. Carborundum is remarkable for lts , hardness, in whlch property it almost, if not quite, equals the diamond.