Sydney B. Bilbrough, analytical chemist and consulting engineer, matriculated through the University of the Cape of Good Hope in 1893 and in 1895 was awarded the degree Bachelor of Arts (BA) by the same institution. By 1910 the firm Sydney B. Bilbrough and Company, consulting engineers, operated in Johannesburg and in 1916 included analytical chemists and assayers. By 1926 the company had its laboratories at 1 Harrison Street, where they remained for the next decade. In 1937 they were listed in the United Transvaal Directory as "analytical, assay and mineralogical laboratories".
Bilbrough was elected a member of the Transvaal Institute of Mechanical Engineers in 1906, participated actively in its proceedings during the next few years, and served on its council for 1908/9. During 1906/7 he contributed a paper on "A dynamical method of determining experimentally the specific heat under constant pressure of superheated steam" and, with F.A.D.H. Moseley* as co-author, "A critical examination of the report of the Natal Coal Testing Commission". Both papers were published in the institute's Journal (1906/7, Vol. 5). In 1911 he was granted a United States patent for improvements in registering and integrating pressure gauges. The next year he became a member of the South African Association of Analytical Chemists (from 1921 the South African Chemical Institute) and was still a member in 1934. Later publications by him included an important paper read before the South African Institution of Engineers, "The prospects of the carbonisation of coal, with by-product recovery, as a South African industry", published as a pamphlet (Johannesburg, 1916, 20p), and a note on the use of the bomb calorimeter to determine the calorific value of coal (Journal of the South African Chemical Institute, 1920, Vol. 3).
In September 1920 the Union Petroleum Company, with Bilbrough as one of its five directors, was registered in Bloemfontein and started prospecting for oil on the farm Elandspoort No. 162, near Amersfoort in the eastern Transvaal (now Mpumalanga). A few hundred litres of oil was recovered from a depth of about 180 meters in 1922.
Bilbrough was survived by his wife Grace Alice, born Douglas. They had no children.