Sir Peter was born in Edinburgh on the 8th of October 1850. He was educated at the Institution and at Edinburgh University, where his studies were to a considerable extent interrupted by the need to give time and attention also to office work. This double training no doubt specially fitted him for the administrative as well as scholarly duties which be undertook when later he became Regius Professor of Mathematics in the United College at the University of St Andrews. He has left a reputation in the University as one who entered with acuteness and readiness into debate, and who showed great enthusiasm and mastery in the many varied undertakings, in and out of college, with which he was concerned.
Tait, who was Professor of Natural Philosophy in Edinburgh in those days, was attracted by this eager student who was distinguishing himself in all his classes. So Scott Lang after graduation in 1872 became Assistant in this department, and thereby a bond of lifelong friendship was formed between the older and the younger man. Those whose memories of our Society go back to these now distant days when Tait was General Secretary, tell us that much of the success of its proceedings was due to the unostentatious and practical help which Scott Lang gave to his friend in relieving him of the detailery of business and in sharing his experimental and mathematical research. Some of the results in mathematical physics appeared in the Proceedings published under his own name.
In 1879, when Chrystal resigned from his Chair in St Andrews after a brief two years, to undertake his long and fruitful work in Edinburgh, Scott Lang was appointed to fill the vacated place. From 1879 till, owing to failing health, he resigned his post in 1921, he served the University of his adoption with conspicuous devotion and breadth of interests. Those of us who were only privileged to know him in his closing years, cannot but be impressed with the influence on student life which he possessed. To his activity and interest stands the credit of building up, outside the classroom, social and other institutions now so widely recognised as useful and important parts of University life.
At the close of forty years' devoted service to the University, Sir Peter resigned his Chair in 1921, receiving honours conferred by Kino, and by Senatus, for his academic and public work. Conspicuous among his labours outside college life was his loyal and active help as a churchman and elder in the St Andrews Presbytery.
He was elected a Fellow of the Society in 1878.