Tyndall, JOHN, physicist, was born 21st August 1820 at Leighlin-Bridge, County Carlow, was employed for a time on the ordnance survey, and for three years was a railway engineer at Manchester. In 1847 he became teacher of physics at Queenwood College, Hampshire, where he began original researches. In 1848 he and his colleague, Dr Frankland, went to Germany and studied at Marburg (under Bunsen); and there, at Berlin, and elsewhere he made investigations into diamagnetism and the magneto-optic properties of crystals. Already an F.R.S., he was in 1853 made professor to the Royal Institution, of which in 1867 he became superintendent. In 1856 Professor Huxley and he made a visit to the Alps, which resulted in a joint work on the structure and motion of glaciers. Tyndall was the first who ever climbed the Weisshorn. In 1859 he began his important researches on radiation; a later subject was the acoustic properties of the atmosphere. In 1874 he was president of the British Association at Belfast, and by the materialist tone of his presidential address raised keen and long-lasting controversies. He was for some years scientific adviser to the Board of Trade and to the lighthouse authorities, but in 1883 retired from most of his appointments and established himself in the country (in Sussex). He was especially famous as a brilliant lecturer and as a popular exponent of modern physical science. The proceeds of a successful lecturing tour in the United States (1872) he devoted to founding scholarships for original research at Harvard and Columbia colleges. Among his honours were the LL.D. of Edinburgh and Cambridge, and the D.C.L. of Oxford. He died (from an overdose of chloral) 4th December 1893.
His works comprise The Glaciers of the Alps (1860); Mountaineering (1861); Heat as a Mode of Motion (1863); On Radiation (Rede Lecture, 1865); a volume on Light, one on Sound, one on Electricity, one on Faraday, and one on the forms of water in clouds, rivers, ice, &c.; also Hours of Exercise in the Alps (1873); Fragments of Science (5th ed. 1876); Essays on the Floating Matter of the Air (1881); and New Fragments (1892).