Electric Lighting in Philadelphia.
The electrical department of the Philadelphia Underwriters Association issues a circular which contains much interesting and useful information regarding electric lighting. It says there are over 5000 buildings in the city wherein electric currents are used for light and power purposes. Out of this number 287 buildings (seven of which are dwellings) have their own apparatus, the latter varying in size from a twenty light to one of 4000 lights. The number of lights furnished by these private plants aggregate 80,258 incandescent and 3325 arc lights. There are fifteen stations, distributing electric currents to all sections of the city, furnishing thousands of lights and power to dwellings, churches and other classes of buildings. ‘I he electric motors in use are of a capacity ranging up to thirty horse-power, and are rapidly being introduced as a more ready motor, in place of steam and hydraulic power in propelling machinery.
All of the different systems of electric lighting indented are, or have been, given every opportunity to operate their tespeclive apparatus, and wherever consistent with safety, approvals were given for use in insured buildings. In innumerable instances, where no insurance was held on buildings, when electric lighting was introduced, contractors were required to install the work in accordance with the underwriter’s requirements and subject to the approval of the latters’ inspection. No insurance loss occurred in any building in the city during the past year from fire where cause could in any way be attributed to electric wires. In reference to lessening the danger in the introduction of electric wires, and the use and handling of light appliances, the circular says :
“ Experience has proven that no perfect insulation can be maintained with the customary method of installing electric wires, where either the conductors or the covering are exposed to mechanical injury or deterioration from affecting influences that may arise, more especially when wires are concealed in Inaccessible places. A like experience with others, no doubt, suggested the invention and introduction of an interior conduit of insulated material which may he secured to the building, and allowing the wires to be drawn in and lay free in the tubes, thus protecting the conductors from injury and preventing any outward fire that might occur from abnormal currents or severing of a wire. This new appliance (manufactured by the Interior Conduit and Insulating Company of New York) has been largely used in our city the past year, and where the system has been continuous, has proven to be, in our opinion, the. best method yet devised for installing electric light wires.”