**Charles Tweedie** was born in Swinton, Berwickshire, on 27 June 1868. His father was George Tweedie (1837-1905) and his mother was Charlotte Lugton (1836-1909). George and Charlotte had married at Duns (Pinkie Smithy), Berwickshire, on 5 May 1864 and their first child to survive was Annie Jane was born in 1866. It was a large family with Charles the third child having younger brothers and sisters Euphemia (born 1870), Charlotte Elizabeth (born 1875), William Alexander (born 1877) and Jessie Isabella (born 1879). Charles also had an older sister Annie Jane (born 1866) and an older brother David (born 1865) who, like Charles, also went on to become a member of the Edinburgh Mathematical Society.

Charles was a pupil at George Watson's College, Edinburgh and while there he was awarded a Sibbald Bursary to study at the University of Edinburgh. He was taught by Chrystal and Tait and it was at this time that his mathematical abilities became clear when he went through the problems in the second volume of Chrystal's Algebra, which at that time was in the proof stage. He graduated with an M.A. in 1890 with First-Class Honours in Mathematics and Natural Philosophy. He was awarded a B.Sc. by the University of Edinburgh in the same year and gained the Bruce of Grangehill Bursary awarded to the best mathematician in the final year. Tweedie decided to study mathematics abroad and went to the leading centre for mathematics in the world at that time, namely the University of Göttingen, in 1891. He also studied at the University of Berlin in the following year before returning to Edinburgh where he was appointed as an Assistant at the University. He was quickly promoted to Lecturer in Pure Mathematics and in this role he supported Chrystal for many years.

He was elected a Fellow of the Royal Society of Edinburgh on 6 December 1897 having been proposed by George Chrystal, Peter Guthrie Tait, Cargill Gilston Knott, John Sturgeon Mackay. He was also a strong supporter of the Edinburgh Mathematical Society serving the Society as Treasurer from 1895 to 1898 and President in 1903-04. He was made an Honorary member of the Society in 1915.

More information about Tweedie is given in an Obituary in the *Proceedings* of the Edinburgh Mathematical Society.

An Obituary of Tweedie, written by E M Horsburgh, appeared in the *Mathematical Gazette*.

**Article by:** *J J O'Connor* and *E F Robertson*