How to Install Electric Bells, Annunciators, and Alarms. / Including Batteries, Wires and Wiring, Circuits, Pushes, Bells, Burglar Alarms, High and Low Water Alarms, Fire Alarms, Thermostats, Annunciators, and the Location and Remedying of Troubles

by Norman H. Schneider

Electric Bells.

The two main types of house bells are the iron box and the skeleton.

The iron box has a cast-iron frame, or base, and a cast- or stamped-iron cover over the mechanism.

The skeleton bell has an iron frame but no cover, and is generally better finished and more expensive than the iron box bells.

For fire alarm purposes, mechanical bells or gongs are made, in which a clockwork mechanism causes the hammer to strike the gong upon being released by electromagnetism.

Marine or waterproof bells have an iron cover fitting tight over a rubber gasket; they are for marine, or mining, work.

Polarized, or magneto, bells are used in telephone work, and are rarely operated by a battery, but have a miniature dynamo generator operated by hand, or power, to supply the actuating current.

Most bells are classed for size by the diameter of the gong, a four-inch bell being one with a gong four inches in diameter; a six-inch bell one with a six-inch gong, and so on.

According to the use for which they are intended, bells may be vibrating, as before described, single-stroke, shunt or short-circuiting, differential, continuous-ringing, or adapted for circuits of high voltage.