Mills Observatory, Balgay Park, Dundee

The Mills Observatory, built in 1935 to designs by James MacLellan Brown, is located within Balgay Park, Dundee. It is a single-story observatory with a cruciform plan, dominated by a two-story drum tower at its center. The building is constructed of red bull-faced sandstone with ashlar margins, and features a papier-mache dome. A projecting cornice runs along the eaves.

The observatory is centrally planned, with an octagonal central core topped by ashlar parapets. An octagonal drum rises from the centre to support the papier-mache dome, which is coated in polymer paint. A pair of glazed timber doors are centrally positioned, flanked by narrow windows. To the left is a single-story, four-bay wing with a blocked cast-iron balustrade and flat-roofed viewing area. A two-story, three-bay stair tower projects to the right, with a canted end bay featuring tall stair windows.

Inside the lobby is a rectangular bronze commemorative plaque mounted on white marble. The plaque features a stylised scrolled scallop pediment, mitred border, and corner bosses bearing astrological symbols, inscribed with details of John Mills, the manufacturer from Dundee, who directed his estate be used to provide an observatory equipped with astronomical instruments for the study of creation.

The building has timber frame sash and case windows with plate glass, and cast-iron rainwater goods. The lobby has a terrazzo floor; glazed timber double doors lead to the octagonal central room with parquet flooring and fitted timber box seating around a central pier. To the rear is a small education room, with glazed timber double doors leading to the stairwell. Art Deco cast-iron railings mark the stairs. The second-story central room has a low ceiling, pine boarded walls and ceiling, a central pier with bent wood benching, and a timber door opening onto a large, paved roof terrace with decorative period cast-iron railings. A narrow, curved staircase leads to a third-story observation deck within the dome, where a telescope mount is positioned. The dome’s rotation, aperture opening, and a canvas screen for weather protection are operated by the original wheel and cog system.

In 1951, St Andrews University installed the current principal (fixed) telescope, which replaced the original 18-inch Newtonian telescope. The original telescope was only suitable for photographic work. The present telescope is a 10-inch refracting fixed telescope from 1871, made by Thomas Cooke & Son, York. It was previously owned by Walter Goodacre, president of the British Astronomical Association, and was located at Four Marks Observatory, Winchester, before being purchased by St Andrews University after Goodacre's death in 1938.