[Sender frames, dial equipment.]
[General view of some of the dial equipment, Trafalgar Central Office.]
[District selector frame in a dial exchange.]
[Early types of switchboards.]
[Early types of switchboards, Old Spring Exchange.]
Styles of Long Distance Instruments
Communications, Telephone Exchange.
Telephone, New York Telephone Co. Exchanges.
[Morse telegraph recorder.]
[Morse Relay machine.]
[Close up of a teletypewriter switchboard.]
[Communication engine room.]