Great Rose Telescope, 1842-1845.
© Science Museum / Science & Society Picture Library
This scale model (1:24) of the Great Rose Telescope was made prior to its construction in 1842-1845, as it includes an observing platform that was never built. Constructed in Ireland by William Parsons, Third Earl of Rose (1800-1867), it was soon known as the 'Leviathan of Parsonstown'. The reflecting telescope used a 6-foot metal mirror weighing four tons. This was mounted in a 15 m tube slung by chains between masive masonry walls. Rose used his great instrument to try and determine the nature of nebulae, misty patches in the sky. He was the first to discover that some had spiral forms. They are now known to be galaxies, remote and masive islands of stars like our own Milky Way.