The establishment of periodic movement in one body by impulses of the same period communicated to it from another body in motion. Thus if two tuning forks are of the same pitch and one is sounded the other will begin to sound by sympathy, the sound waves communicating the necessary periodic impulses to it. Sympathetic [...]

A switch, so constructed that by turning its handle connection can be made from one lead to either of two other leads, and also so that connection can be completely cut off.

A switch for changing storage battery connections from series to multiple and back again.

A switch constructed to give a quick, sharp break. It has a spiral spring interposed between the handle and arm. As the handle is drawn back to open it the spring is first extended, the bar being held by the friction of the contacts, until the spring suddenly jerks it up, thus breaking the contact.

A switch, often of the plug type (see Plug Switch) for changing the direction of current passing through a galvanometer.

A switch for changing the direction of the current in a circuit.

A switch which in the swing of its bar connects one by one with a number of contacts so that ultimately the end of its bar is in contact with all at once. It is used to throw lights in and out in succession, and it can, if the multiple contacts connect with resistances, make [...]

A switch whose movable arm is a narrow, deep bar of copper or brass, and which in making contact is forced in edgeways between two springs connected to one terminal. The bar is connected to the other terminal. Synonyms–Knife Break Switch–Knife Edge Switch.

A heavy switch, often of double contact type, for connecting and disconnecting feeders from bus bars in central stations.

A heavy switch for central station work, that connects and disconnects two leads simultaneously.