Sydney Observatory is located on Observatory Hill at Millers Point. This heritage listed observatory was designed by Alexander Dawson and James Barnet and built in 1858 in the Victorian Free Classical architectural style. It was essential to shipping, navigation, meteorology, timekeeping and the study of stars seen from the Southern Hemisphere. The central tower features a weather vane and a time ball, which signalled the time to ships and to the General Post Office in Martin Place. It is still raised to the top of its post and dropped at exactly 1pm every day. Government Astronomers worked and lived in the building until 1982, when it became part of the Museum of Applied Arts and Sciences.