The machine may have only one switch or any number of switches. The connection to motor may be by belt or chain, or the motor may be directly connected to the worm gear.
Flash System of Gas Lighting—This system for simultaneously lighting a large number of gas burners, is used in large halls, churches, theatres, etc. Two sparking points, each insulated one from the other and from the burner, are arranged at each burner, so that a spark between the points passes through the jet of gas and ignites it. A number of sparking points and the secondary of an induction coil are connected in series. When the circuit through the primary of the induction coil is closed, sufficient pressure is induced in the secondary to cause sparks to jump across every jet in the series. Since the voltage is high, the wires must be installed with great precaution. The wire should be enclosed in glass tubing wherever it comes within less than 1¼ in. from the gas piping, except where purposely grounded.
High Speed Flashers.—Machines of this type are used for giving what is generally known as high speed effects, such as fountains, water, steam, smoke and fire effects, whirling borders, revolving wheels and work of a similar nature.
Fig. 1,019.—Dull's high speed flasher. It is mounted on a slate base 12 inches wide, the length being governed by the size of the machine. Motion is given to the rotary switches through worm and belt gearing. Iron cams are used, the current being taken therefrom by six-leaf brushes, provided with stiffeners. The wiring for the machine is simple; 4 c.p. lamps can be run on one wire. A border or ornament containing 160 lamps requires 12 wires between the sign and flasher. The flasher is made in 4 switch sizes only, viz.: No. 4, 8, 12, 16, etc. This is due to the fact that there are three parts of light to one of darkness.
Lightning Flashers.—These machines are for giving the appearance of a streak of lightning going across a display. There is very little expense attached to their operation, because not more than two-thirds of the lamps are turned on at one time, and this number for only about one-sixth of the time, as compared with the sign burning steadily.
Lightning strokes can be utilized in various ways, either alone or with other advertising pieces. Alone they can be placed along a cornice, across the front of a building, up and down the corners leading to a doorway, etc. They can be used in the center of a sign with letters above and below. In this case, it is best to alternate the stroke with the letters, that is, flash the wording on and then off. As soon as it goes out, the stroke flies across in the darkness, then the wording comes up again, say six times a minute.