Born Aug. 4, 1805, in Dublin; died Sept. 2, 1865, in Dunsink, near Dublin. Irish mathematician; member of the Irish Academy of Sciences. He became a professor of astronomy at the University of Dublin and director of the university’s astronomical observatory in 1827.

In 1833-35, in the Transactions of the Irish Academy of Sciences, Hamilton published a work in which, almost simultaneously with H. Grassmann, he gave an exact formal presentation of the theory of complex numbers and constructed an original system of numbers, the so-called quaternions. This study was one of the sources for the development of vector calculus. In mechanics, Hamilton used the variational method (the so-called Hamilton principle).