Monument MPM1700 - Site of Naval Telegraph Semaphore Station

Site of the first Naval telegraph in Portsmouth, erected on Portsdown Hill in 1795. One of a line of shutter semaphore stations which operated between Southsea common and London, allowing messages to be passed between the fleet at Portsmouth and Admiralty in London.

Site of the first Naval telegraph in Portsmouth, erected on Portsdown Hill in 1795. The telegraph was one of a line of shutter semaphore stations which operated between Southsea common and Whitehall, transmitting messages between the fleet at Portsmouth and Admiralty in London. The semaphore used a series of revolving shutters held in a frame, which were opened and closed in different variations in order to represent specific words, enabling messages to be conveyed between Portsmouth and London within minutes.

The shutter station was replaced after the Napoleonic Wars by a new Semaphore Telegraph located near Camp Down, at the eastern end of Portsdown Hill. The new semaphore stations transmitted messages using two signalling arms, rather than shutters. The need for semaphore ceased in 1847 when it was replaced by the electric telegraph.

Gates, William G, 1900, Illustrated History of Portsmouth (Bibliographic reference). SPM299.

Hunt, Bob, 2005, Portsdown Tunnels (Bibliographic reference). SPM245.