Thomas Cooke, John Smeaton, and Observatory, York green plaque

This green commemorative plaque records: This Observatory was built by the Yorkshire Philosophical Society following the inaugural meeting of the British Association for the Advancement of Science in 1831. It has an earlier rotating roof designed by John Smeaton who also designed the Eddystone Lighthouse. The Observatory housed what was for many years the largest refracting telescope in the world, designed and built by Thomas Cook of York, whose firm also built the Greenwich transit instrument. It was restored and refitted to mark the British Associations 150th Anniversary meeting in York in 1981 and was officially opened by its President H.R.H. the Duke of Kent, G.C.M.G., G.C.V.O. Recorded plaque organisation: York Civic Trust.

John Smeaton, FRS, designed the Observatory's rotating roof and is renowned for his work on the Eddystone Lighthouse; Thomas Cooke was a York-based telescope maker whose firm constructed what was once the world's largest refracting telescope housed in this Observatory.