Only a handful of the medals were commissioned by John Smeaton
A rare medal which protected the bearer from being sent to serve at sea by Royal Navy press gangs has gone on display at a Cornish museum.
The Eddystone medals were given to 18th Century lighthouse builders to prove they were exempt from going to war.
They were commissioned in 1757 by John Smeaton, who oversaw the construction of the third Eddystone lighthouse, which now stands on Plymouth Hoe.
At the time Britain was fighting the French in North America.
Dragged to war
Only a small number of the solid silver medals were made and they were given to men working on the new lighthouse as a sign that they were doing important and skilled work and were to be left alone by the press gangs.
The medal bears an inscription in Latin which relates to the destruction of the previous Eddystone Lighthouse in a fire.
It reads: "Consumed by fire December 6th 1755. Restored on the rock (it is hoped immovable) by virtue and the auspices of Robert Weston benefactor 1757. John Smeaton, Architect."
Sarah Riddle, curator at the National Maritime Museum Cornwall in Falmouth, said: "We believe that this medal is unique.
"It brings to life the torment of the press gangs, who would drag men to war during the 1700s."
The medal, which is normally on display in Plymouth, forms part of an exhibition on lighthouses at the museum.