Medium: Digital print on canvas Dimensions: 40" x 42" The Leviathan of Parsonstown is a six foot telescope built in 1845 by William Parsons, 3rd Earl of Rosse on his estate, Birr Castle, at Parsonstown, Ireland. The historic reflecting telescope of 72 in. aperture, was the largest telescope in the world from 1845 until the construction of the 100 in. Hooker Telescope in 1917. Parsons discovered that several nebulae had a spiral structure, suggesting "dynamical laws".