It spent hundreds of years languishing on the seabed off the Isles of Scilly in the far south-west of Britain before being hauled back to the surface by divers and setting off a circumnavigation of the world.
Finally the Pednathise Head astrolabe – a rare example of a 16th-century navigational instrument once used by sailors to determine latitude – is back on Scilly after being rediscovered on the other side of the Atlantic.
