EMS honours James Leslie

On Friday 4 November 1932, 100 years after the death of James Leslie, the Edinburgh Mathematical Society held a meeting in his honour:-
Centenary of Scottish Mathematician.

The centenary of the death of Sir James Leslie the noted Scottish mathematician and natural philosopher, was commemorated yesterday by the Edinburgh Mathematical Society, at their opening meeting of the session in the Mathematical Institute, Chambers Street, Edinburgh. The Society took as read four formidable papers on modern mathematics in order to devote its meeting to the centenary celebrations, the main feature of which was a lecture delivered by Dr E M Horsburgh, Reader in Technical Mathematics in the University of Edinburgh.

Sir James Leslie was Professor of Mathematics in Edinburgh University from 1805 until 1819, and Professor of Natural Philosophy from 1819 until his death in 1832. The author of a number of scientific works, he was one of the pioneers of the scientific renaissance of the last century.

Among those present at the meeting yesterday was the great-great-grand-niece of Sir John Leslie. Mrs Leslie, widow of his great-grand-nephew, acted as hostess along with Mrs Horsburgh. Loan collections of mementoes were on view.

A portrait (after Wilkie) and bust (Joseph) were lent by the University authorities; the Leslie instruments by Professor Barkla and the Deportment of Natural Philosophy; a collection of letters and publications by Mr Nicholson and the University Library; further letters by Dr Marjoribanks, Colinton; and a large number of personal relics by Mrs Leslie.

The name Leslie, said Dr Horsburgh in the course of his lecture, was famous in the troublous times of Scottish history, but the Leslie whose name was enshrined in the M'Ewan Hall made his conquests in the fields of science. He was considered by his contemporaries to know the whole field of mathematics and physical science of his day. Such a position was then possible. Science applied to engineering had run in each generation of this branch of the Leslie family, and the nephew of Sir John founded Leslie & Reids, civil engineers, one of whose activities had been to give to Edinburgh a water supply second to none in the world. Sir John Leslie was born in 1766 in Upper Largo, Fife, where his little cottage may still be seen. These were primitive days of spartan simplicity, in a poor country, whose the well-to-do travelled by horse, or stage-coach, instead of by aeroplane, and merchandise was carried on land by pack-horse or lumbering horse wagon, instead of by railway train and motor car, and at sea by the bluff-bowed bid vessel, instead of the modern liner. At the age of four he was sent to a sort of school, where an ancient dame, plying her spindle in an earth floored room, taught the letters of the alphabet to children. Here he sat on a stool beside the peat fire, a seat reserved for the youngest and feeblest. In this foretaste of a professorial chair he remained content, till displaced by an even younger child; when, with dignity outraged, he hid for a whole day and refused ever to return to the school. Though feeble in body he was strong in mind.

Some eight months' schooling, marked by his violent antipathy to Latin - perhaps still the universal language - was all he ever had in his life, but the kindly minister of Largo lent him some scientific books. These he mastered, by himself, and, at the mature ago of 13, entered the University of St Andrews, His parents must have been hard-pressed to find the money, but such sacrifices produced fine characters; he was found qualified for the senior class in mathematics, and at the end of the year he gained a prize. He promptly crossed swords with the University authorities by refusing to wear a gown, and upheld his position by research into the ancient charters. He won his case. He was self-reliant, as well as self-taught. His early ambition was to attend the class of Natural Philosophy, but this was made contingent on his learning the hated language, Latin. In the end he did learn it, and took to it, and used to quote Latin frequently in his many writings. At an early age he met Playfair, the future professor of mathematics in Edinburgh. There was little scope then for a young man, however brilliant, who had just left a University. Leslie followed a usual course, and became tutor in a private family, the Wedgwoods of pottery fame. At an early age he began his long course of scientific experiment and publication, and supported himself by his pen till the age of 33. His wants were simple, and he was able to travel widely.

In 1805 at the ago of 39 he was first favourite for the Chair of Mathematics in the University of Edinburgh, from which his friend, Professor Playfair, had been translated to the Chair of Natural Philosophy. Here began a famous heresy hunt. The Edinburgh ministers were suspected of endeavouring to secure a monopoly of the Philosophical Chairs, and they accused Leslie of atheism from a note in his work on heat. Leslie had mentioned with commendation the name of Hume. A protest was tendered by the ministers to the patrons of the University chairs, stating that they wore obliged by charter to act with the advice of the ministers. After a violent controversy Leslie was at last elected. Later he was even received into favour. His position was now secure.

He remodelled the University mathematical course, and wrote mathematical text-books. On the sudden death of his friend Playfair in 1819 he was called to the Chair of Natural Philosophy. This was his true position in life. He devoted himself with enthusiasm to improving the course pf Natural Philosophy, introduced copious experiments, and began to write a complete scheme of text-books. These gave a clear idea of the state of physical science in Leslie's day. There was a strong practical tendency in Leslie's science. Knowing the history of the subject as well as he did, he knew exactly where to begin his experimenting. He was a great instrument-maker. He had a distinct tendency to engineering problems, though he professed to write as the pure scientist. In his extension of his treatise on Heat he dealt with the applications of temperature to climate, and showed his ambition to lay the foundations of meteorology. We might perhaps look on him as the founder of this science. He was also the pioneer of refrigeration. Perhaps his most celebrated student was Thomas Carlyle.

In 1832, on the recommendation of Lord Brougham, then Lord Chancellor, he was created a Knight of the Guelphic Order. Leslie rather despised titles, and preferred his old distinction as Professor. He was proud of being elected Corresponding Member of the Royal Institute of France by 30 out of 37 votes. He had outgrown his early delicate health and was active, though corpulent. But while gardening on his small estate, Coates, near Largs, he caught a chill, which he neglected, as medicine was not a proved branch of physical science. This illness proved fatal, and he died in 1832 in his 67th year.

Leslie was kindly and self-reliant. His writings were at times grandiloquent. He was too striking in appearance to be spared by caricature. Quaint tales were told of his oddities. When experimenting on the effect of dyes on animal fibres, he is said to have used his own hair and to have appeared before his delighted students with patches of his hair all the colours of the rainbow. Such a philosopher must have been also a good disciplinarian.

In the course of his lecture Dr Horsburgh discussed some of the most famous of Leslie's many works.