This is a photograph of a map of the observatory and grounds, drawn by the OS in 1867. The round raingauge was on the North lawn. The anemometer and the square raingauge were situated on the roof of the main building and the thermometers were placed in a metal box attached to the north window of the East Tower. In 1867 a meteorological building was constructed by the Board of Trade to house the instruments of the Automatic Weather Station where they operated continuously until 1883. This building was demolished in 1963 to provide space for a new Library (marked with a crossed square in the map).
The pencilled outlines of the Robinson Dome were inserted later, as this building was not constructed until 1885.The original map is 1350mm by 920mm and is situated on the wall of the SE basement office.