**Arthur Cayley**, was born on August 16, 1821, and died on January 26, 1895. He was an English mathematician who made a major contribution to the advancement of pure mathematics. Graduating (1842) at Trinity College, Cambridge, he later entered law and was admitted (1849) to the London Bar. Cayley developed the theory of algebraic invariance, and his development of non-dimensional geometry was applied in physics for the study of CONTINUOUS SPACE-TIME QUANTITY.

Cayley's work on algebraic matrices served as a foundation for Quantum Mechanics, which was developed by Werner Heisenberg in 1925. Cayley also suggested that EUCLIDIAN GEOMETRY and NON-EUCLIDIAN GEOMETRY are special types of geometry.

He united Projective Geometry (which is dependent on invariant properties of figures) and Metric Geometry (dependent on angle sizes and line sizes). Cayley's mathematical documents were published in Cambridge (1889-98).

Bell, E.T., Men of Mathematics (1937; repr. 1986); Prasad, Ganesh, Some Great Mathematicians of the Nineteenth Century, vol. 2 (1934).