In 1958 the London Planetarium was opened by Prince Philip, Duke of Edinburgh on 19 March, with public presentations commencing on the 20th. It occupied the site of an old cinema that was destroyed in the Second World War, and seated an audience of around 330 beneath a horizontal dome approximately 18 m in diameter. For its first five decades of operation, an opto-mechanical star projector, a Zeiss projector Mark IV, offered the audience a show based on a view of the night sky as seen from earth. Between 1977 and 1990, evening laser performances called 'Laserium' (see Ivan Dryer) were held.