Balfour Stewart, a.British physicist, born in Edinburgh, Nov. 1, 1828. He studied in the universities of St. Andrews and Edinburgh, and in 1852 engaged in business in Melbourne, Australia; but in 1854 he retired to Richmond, near Melbourne, and devoted himself to science. In 1855 he returned, and was assistant for six months to John Welch, superintendent of the Kew observatory, and afterward for three years to Prof. Forbes in Edinburgh, lecturing on mechanics and assisting in experiments. In 1859 he was appointed superintendent of the Kew observatory, and in 1861 examiner in the universities of London and Edinburgh. In 1868 he received the Rumford medal from the royal society. In 1870 he was appointed professor of natural philosophy in Owens college, Manchester, still retaining the directorship of the Kew observatory. Besides several papers in the "Transactions " of the royal society, he has published "Elementary Lessons in Physics" (London, 1870); " Elementary Treatise on Heat" (1871); "Physics Primer" (1872); and "The Conservation of Energy " (1873).