THE INSTALLATION OF ELECTRIC LIGHT WIRES
IN a paper read by Edward H. Ellicott, city electrician of Chicago, before the recent convention of the National Firemen’s association of the United States, held at East St. Louis, Ill., the writer pointed out that, while the extensive use of the incandescent system and the are light system of electric lighting had been made possible by Edison and Brash, no safe manner of installing the necessary wiring had been devised by them. Such a system (he showed) had been one of evolution from ft plain cotton-covered wire, held in place by metal staples or wooden cleats, succeeded by a wire supported in much the same manner, but with an insulation of a cotton covering saturated with a white lead preparation, later on treated with a weatherprootlng compound, and sometimes mounted on porcelain knobs, while safety fuses were employed to protect the wires from a dangerous quantity of current, and rubber bushings where wires passed through walls. Then came the use of a wire coated with a rubber compound and protected with a braid, the mounting of all contacts on porcelain bases, the use of porcelain, instead of wood cleats, and glass and porcelain tubes. Next the wires were inclosed in a thin,brass, paper-lined conduit, followed by the use of a steel pipe conduit, glazed on the inside to facilitate the drawing in of the wires.
The diversified use of electricity and its adaptability to any purpose have rendered necessary the adoption of general rules regarding the installation of wires in buildings—the character of work for the several classes of service being necessarily widely different. These wires are either high or low-tension. The first carry a current dangerous to life; the second, one which, as a rule, can be handled without any risk. On high-tension wires the commercial voltage is 500; It has now risen to 8,500, and is apparently keeping a little ahead of the improvements in wire installation.
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