Wires used for batteries, bells, telephones, etc., operated by batteries and where the voltage is not over 20 volts, may be run under insulated staples or wooden cleats inside of a building. If outside and exposed to the weather, they should be mounted on suitable glass or porcelain knobs.
Fig. 90.—Porcelain Insulators to support Electric Light Wires.
Electric-light wires for inside use are commonly supported by insulators made of porcelain and known as cleats, knobs, and tubes according to the shape.
Telegraph, telephone, and power lines are usually supported by glass knobs or large porcelain insulators which screw on to wooden pins.
Fig. 91.—Glass Insulator Binding-Posts and Pin used to support Telegraph and Telephone wires.
Binding-Posts
Binding-posts are the most convenient device to make quick connections between wires and other parts of electrical apparatus.
Binding-posts may be either made or purchased. Those which are purchased are of course the best, and will add greatly to the appearance of any instrument upon which they are mounted.