1851 Great Exhibition: Official Catalogue: Class X.: Joseph Burdett
425. BURDETT, JOSEPH, 28 Hanover Square, Clapham Road — Inventor.
Domestic telegraph, requiring only one bell for any number of rooms. All the rooms being numbered, wires are brought to corresponding numbers on this machine, so that when the wire of any room is agitated, the bell will ring and the indicator will point out the number of the room on the dial where attention is required.