Lewis Simons was awarded the Bachelor of Science (BSc) degree at King's College, London in 1915. He came to South Africa that same year to take up an appointment as lecturer in physics at Victoria College, Stellenbosch (which became the University of Stellenbosch in 1918) and was admitted to the Bachelor of Arts (BA) degree by the University of the Cape of Good Hope in recognition of his overseas qualification. In the second half of 1917 he was appointed senior lecturer in physics at the South African College, Cape Town (from 1918 the University of Cape Town) and remained in that position to 1921 or 1922. He turned out to be a good lecturer and a promising researcher. As the professor of physics, Professor J.C. Beattie*, became the principal of the university early in 1918, Simons was acting professor of physics until the arrival of Professor Alexander Ogg* more than a year later.
Simons became actively involved in research and publication shortly after his arrival and during the few years he remained in South Africa contributed the following papers to the Transactions of the Royal Society of South Africa: 'Ionization of gases and the absorption of Roentgen rays' (1917, Vol. 6, pp. 311-323), 'On the velocities of two distinct groups of secondary corpuscular rays produced by a homogeneous Roentgen radiation, and their absorption coefficients in various gases' (1919/20, Vol. 8, pp. 73-87), and 'Detection of induced beta-ray emission from substances exposed to Roentgen rays by a photographic method' (1921, Vol. 9, pp. 297-301); also, 'The beta ray emission from thin films of the elements exposed to Roentgen rays' (Philosophical Magazine, 1921, Vol. 41, pp. 120-140).
Simons was a member of both the Royal Society of South Africa and the South African Association for the Advancement of Science during his stay in South Africa. At the association's annual congress held in Stellenbosch in 1917 he served as joint secretary of Section A (which included physics).
Shortly after his return to the United Kingdom Simons obtained the degree Doctor of Science (DSc). He was affiliated with Birbeck College, University of London, during the nineteen-twenties and continued his research on the same topics as during his stay in South Africa. For example: 'Low velocity X-ray electrons' (Philosophical Magazine, 1923), 'The X-ray emission of electrons from metal films, with special reference to the region of the absorption limit' (Proceedings of the Physical Society of London, 1924), and 'An investigation of the production of positive and negative electron pairs in a cloud chamber' (with K. Zuber; Proceedings of the Physical Society of London, Series A, 1937).