Armagh Observatory, College Hill, Armagh BT61 9DG, +44 (0)28 3752 2928
John Arnold and his family
Science Museun, London
In this portrait, John Arnold is shown with part of the mechanism for one of his marine chronometers. He vied with Earnshaw for the Board of Longitude prize, and was accused by Earhshaw of copying and patenting Earnshaw's escapement.