In 1926 the National Geographic Society, in cooperation with the Smithsonian Institution, financed an expedition to South-West Africa (now Namibia) to measure the intensity of solar radiation.
He visited the mountain in the company of Mr A. Dryden, inspector of works at Keetmanshoop, who played a major role in the planning and building of the observatory.
A shallow tunnel, 3 m wide and 2.2 m high, was excavated by blasting and extended outwards by cemented stone walls and a concrete roof to a total length of 10.5 m. This space was divided into three small rooms by wooden partitions and a stone instrument platform built in front of it.
The altitude of the sun at the time of each observation was measured with a theodolite, so that the amount of air through which the radiation had passed could be calculated.
The stone platform also contained a coelostat, consisting of two flat mirrors, one of which was driven by clockwork and mounted so as to keep the sun's rays reflected continuously through an opening in the northern wall of the tunnel.
They reached Cape Town on 13 September 1926 and after travelling to Keetmanshoop by train moved their instruments and household goods to the observatory by ox-waggon.
She collected various mammal, bird, reptile, insect and plant specimens, which she donated to the National Museum of Natural History.
[12] He was replaced by a South African, Arthur Bleksley, who stayed for some six months before accepting a more permanent post in Johannesburg.
Its work was considered important enough locally to deserve a mention in the "Official Year Book of the Union of South Africa",[14] which also reported its closure.
[16] Several years later, when reporting recomputed daily solar constant values for the period 1923 to 1939, Abbot had distanced himself from the Brukkaros Observatory, describing it as 'so far inferior that its results have not been reduced' and 'subject to sources of error which we have now eliminated'.
At that time they represented the longest series of measurements of the solar radiation incident on the central plateau of southern Africa.