William Parsons (1800-67), third earl of Rosse, was responsible for building the largest telescope of his time, nicknamed the 'Leviathan'. It enabled the earl to describe the spiral structure of galaxies. This volume reissues two contemporary accounts of the telescope. The first, published anonymously in 1844 and later revealed to be by Thomas Woods, provides a comprehensive description of the workings of both the 'Leviathan' and the smaller telescope...