... Armagh Observatory, College Hill, Armagh BT61 9DG, +44 (0)28 3752 2928 . ... A gradual awareness of the great importance of the stability of foundations for instruments, which began in Scandinavia, early in the 18th century, reached its ultimate fruition in the Observatory of Trinity College, Dublin built at Dunsink in 1785. ... Indeed, Armagh Observatory which was built in 1789-91 received its principal instrument, The Troughton Equatorial Telescope , in 1795, a decade earlier than Dunsink. ...