In March 1912, the Magnetograph House was erected. This structure contained the magnetograph equipment that was used to measure variations in the South Magnetic Pole. It was difficult to find a suitable location to set up the structure on Cape Denison, as a large flat area was needed for the equipment. As a result, explosives were used to clear a site approximately 400 m to the northeast of the Main Hut.
The Magnetograph House was purchased prior to departure from the Risby Brothers, Timber Merchants of Hobart, for a price of £16/15/-. It was supplied ready to construct, with an Oregon frame, Baltic pine linings and one external door-set.
The construction process was made in two attempts, the initial attempt being demolished by strong winds during its construction. The structure was lined with tar-paper, secured to the frame with battens. Fixings generally were small copper nails (so as not to interfere with the magnetic measurements) and these were taken from the shipwrecked Clyde. Large rocks were located around the hut to provide a wall-like barrier to the weather, allowing the internal temperature to be relatively constant. Sheepskins and hessian were also attached to the roof for this purpose.
The structure was rectangular in plan (5.5m x 2m) with a shallow pitched skillion roof and no windows. The entry was constructed as a double porch, with three door-sets, to assist in the maintenance of the constant internal temperature. The external door was a double ‘stable’ ship’s door taken from the Clyde. A copper ventilator was installed in the roof over the porch for the same reason. The equipment was set into the rock to ensure a level surface.
Magnetic measurements were collected from the Magnetograph House on a daily basis, usually by Eric Webb (Chief Magnetician) but also by Edward Bage (Assistant Magnetician).