The
restored Leviathan of Parsonstown and rainbow. The telescope was built by William Parsons, 3rd Earl of Rosse. It has an aperture of 72 in (1.8 m) and was the largest in the world from 1845 until the construction of the 100-inch (2.5 m) Hooker Telescope on Mt Wilson in 1917.
But no pots of gold at the end of the rainbow.
Photo credit: Richard Fleet, Glows, Bows & Haloes