LETTERS IN ELECTRIC LIGHT.
In the following illustrations are shown plans of a sign to be electrically illuminated. The electrical work is necessarily done in the electric working shops, but as many illuminated signs are being used nowadays, the description may be useful to decorators who contemplate putting in something of the kind. In the first figure the letter is on a casing, A, having a back or support carrying incandescent lamps in channels. The form of the letter is sheet metal and is set-screwed to the base piece at the places marked C. The disks B are plate glass colored to conform to the requirements. The commutator is shown in the other figures. In the first, E is a wood cylinder, which turns in bearings, D. F F are spring contractors, and G G wire connections which join those of the lights. Another view is in the next drawing, in which the cylinder is B, bearings D and spring contractors C. The cylinder is driven by a small electric motor, G, through a reduction gear, consisting of a train of wheels or worm gearing, as at F and E. The spring contacts are electrically joined to the terminals of the lights. The terminals are joined by a combined return to one pole of the source of electric supply, and the other pole is connected to the contact pieces. The rotation of the cylinder consequently breaks and joins the circuit as desired, producing alternate changing of the lights and colors, resulting in attractive effects.
