Mathematician and inventor. Born in Dysart, Fife. Wallace worked as a bookbinder and taught himself mathematics, becoming first a private tutor and then a maths teacher in Perth Academy (1794).
John Playfair (1748 - 1819) recommended Wallace for a Professorship at the Royal Military College (Sandhurst) where he became a colleague of Sir James Ivory (1765 - 1842). On Playfair's death, Wallace fell heir to his Chair at the University of Edinburgh, where he developed a reputation as an outstanding teacher. Mary Somerville (1780 - 1872) was one of his students.
Wallace worked on geometry and also invented the pantograph, used to duplicate line-work on pictures or maps at greater or smaller scale. He wrote a number of articles and books on mathematics and named one of his concepts Simson's Line after another Scottish mathematician Robert Simson (1687 - 1768) in 1799.
Wallace also worked and published in astronomy and took an active interest in the erection of the Observatory on the Carlton Hill (1792).
Wallace retired from the University in 1838 due to ill health and died in Edinburgh.