Computer science development of sophisticated computing equipment. Wilhelm Schickard designed and constructed the first working mechanical calculator in 1623. In 1673, Gottfried Leibniz demonstrated a digital mechanical calculator, called the Stepped Reckoner. He may be considered the first computer scientist and information theorist, for, among other reasons, documenting the binary number system. In 1820, Thomas de Colmar launched the mechanical calculator industry when he released his simplified arithmometer, which was the first calculating machine strong enough and reliable enough to be used daily in an office environment. Charles Babbage started the design of the first "automatic mechanical calculator", his Difference Engine, in
David Bevan (mathematician) David Bevan (mathematician) David Bevan is an English mathematician, computer scientist and software developer. He is known for Bevan's Theorem, which gives the asymptotic enumeration of grid classes of permutations and for his work on enumerating the class of permutations avoiding the pattern 1324. He is also known for devising weighted reference counting, an approach to computer memory management that is suitable for use in distributed systems. Bevan is a lecturer in combinatorics in the department of Computer and Information Sciences at the University of Strathclyde. He has degrees in mathematics and computer science from the University of Oxford and