Professor Sampson collaborated with James MacLellan Brown, the City Architect, in designing a much more modern building than the one originally planned before the war. The structure is of sandstone blocks quarried from , near Rosemill. The Observatory was formally opened by Professor Sampson on 28 October 1935, and presented to the Town Council by Mr. Milne of the Mills Trust in the presence of Lord Provost Buist. A message of congratulation was sent by the Astronomer Royal at Greenwich, Sir H. Spencer Jones. Articles on current celestial objects were written in the local press by the Reverend John Lees, who usually acted as chairman at public lectures given at the Observatory by visiting astronomers.