Photograph of the building that houses Airy's 'Great Equatorial', at the Royal Observatory, Greenwich. Sir Howard Grubb of Dublin in Ireland built the 28 inch refracting telescope in 1893. He used an earlier mounting made by Ramsome & Sims of Ipswich in England. This building had previous housed a 12 inch refracting telescope. Due to its considerable larger dimensions the existing cylindrical dome was replaced with one with a bulbous form. Known as the 'Onion Dome', this has become the observatory's trademark that now forms part of the National Maritime Museum. Despite its age, Airy's 'Great Equatorial' remains the largest refracting telescope in England.
© Science Museum / Science & Society Picture Library