Wallace Broad was a foundation member and the first vice-president of the Rhodesia Scientific Association, established in Bulawayo, in present Zimbabwe, in May 1899. At that time he had a Bachelor of Arts degree, and was a Fellow of the Geological Society of London. In 1900 he was elected as the second president of the association, but resigned during his year of office and appears to have left the town, if not the country.
During 1900 Wallace read a paper on "Methods of study in natural science (Rhodesian rocks)", which was published in the association's Proceedings for 1899-1900 (Vol. 1, pp. 21-25). In this paper he argued that the forces that currently modify the earth's crust and their effects should be studied, as the resulting knowledge would be useful in interpreting the geological record. At the association's conversazione in July 1900 he exhibited a stratigraphical collection of Rhodesian rocks. During a later discussion he was described as a "keen geologist". In 1904, in a letter published in the (British) Mining Journal (pp. 391-392), he commented on and criticized an article on "Gold mining in Rhodesia" by F.C. Roberts.