An eminent mathematician, born in Dublin; such was his precocity that at 13 he was versed in thirteen languages, and by 17 was an acknowledged master in mathematical science; while yet an undergraduate at Trinity College, Dublin, he was appointed in 1827 professor of Astronomy in Dublin University, and Astronomer-Royal of Ireland; his mathematical works and treatises, of the most original and a far-reaching character, brought him a European reputation, and embraced his "Theory of Systems of Rays," "A General Method in Dynamics," and the invention of "Quaternions"; he was knighted in 1835 (1805-1865).