... he resumed attendance at the University with the object of qualifying for an honours degree. At the University he gained medals in natural philosophy and English, and took honours in mathematics, moral philosophy, education, geology, and natural history. He was also awarded the Neil Arnott Scholarship in experimental physics as "the most distinguished student of the year in the physical laboratory of the University," and he assisted the late Professor Tait for one year with the teaching in the laboratory.Clark graduated M.A. from the University of Edinburgh in July 1889 with Honours. In 1889 he was appointed Mathematics and Physics Master at George Heriot's School, Edinburgh. He held this position until 1908 when he was appointed Headmaster of the School. He remained Headmaster until he retired in 1926. Clark married Mary Mackay in 1891.
Among the honours Clark received was an LL.D. and an C.B.E. in 1935.
Clark was an active participant in a number of organisations. For example he was a member of the Edinburgh University Physical Society and served a term as President. He joined the Edinburgh Mathematical Society in December 1885. He served on the Committee in 1890, was Secretary of the Society from 1891 to 1896, Vice-President for session 1896-97, and then President for session 1897-98. He left the Society in 1922. Clark was elected to the Royal Society of Edinburgh on 2 February 1891, his proposers being Sir John Murray, David Fowler Lowe, Peter Guthrie Tait, George Chrystal. He served the Royal Society of Edinburgh as Councillor from 1928 to 1931, and Vice-President from 1931 to 1934.
Article by: J J O'Connor and E F Robertson