3 photographs showing three telescopes at the Royal Observatory, Greenwich

Glazed wooden picture frame containing 3 photographs showing three telescopes at the Royal Observatory, Greenwich. These are a 13-inch astrographic refractor by Sir Howard Grubb and Sons Limited used for the Carte du Ciel, the Thompson telescope (26-inch refractor and 30-inch reflector) and the Great Equatorial, a 28-inch refractor.