Murray Shutter Telegraph
1796 · Shutter Telegraph · Work 123 of 1,871
A Murray shutter telegraph frame on the roof of an Admiralty station on the London to Deal chain, six octagonal wooden shutters turned edgewise or flat in their upright frame, operating cords running below.
- What it was used for
- The Admiralty's channel from Whitehall to the naval ports. Lord George Murray proposed the system on 17 October 1794; the first line, to Deal with fifteen stations, was finished on 27 January 1796, and by 1808 four lines ran to Deal, Portsmouth, Plymouth and Yarmouth, several dozen stations in all. They were manned by navy personnel, two at the telescopes, two on the shutters, under a lieutenant. They carried orders to the fleet and readiness reports back; on 6 November 1805 the news of Trafalgar went from the shutters on the Admiralty roof to Portsmouth. A message to Deal took about seven minutes, one to Portsmouth about a quarter of an hour in good conditions. Murray offered to build all the lines for 16,500 pounds and received 2,000. After Napoleon's abdication and the Peace of Paris the Admiralty had the lines dismantled in 1814; after the return from Elba the Portsmouth route had to be hurriedly put back into service.
- What was new
- Against France and Sweden nothing here was first. Chappe was already running, Edelcrantz tested his installation as early as late October or early November 1794, and Holzmann holds Murray's six shutters to be a reduced version of Edelcrantz's ten-shutter design; Edelcrantz himself wrote in 1796 that the English device was, as far as the shutters went, similar to his own but otherwise quite different. Proof of borrowing is missing in both directions; the question stays open. It was new against Britain's own previous practice: six shutters in a frame twenty feet high gave 63 settings, enough to spell out any text, in place of the fixed meanings of the earlier ball and flag signals.
Connections
Every connection names its kind. “Forerunner” on its own would be a claim.
- Follows fromChappe Telegraph1793Murray put his offer to the Admiralty on 17 October 1794. In footnote 11 J. D. Davies names Chappe's French telegraph as the thing that had excited the interest of both Murray and Gamble. The shutter design itself is Murray's own.Source: J. D. Davies, Lord George Murray, Bishop of St David's and progenitor of the internet (PDF)