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
Automatic revolver Automatic revolver An automatic revolver is a revolver that uses the energy of firing for cocking the hammer and revolving the cylinder, rather than using manual operations to perform these actions. Examples of genuine semi-automatic revolvers are rare, and the term is more often applied to break-open revolvers with automatic systems for ejecting spent casings on opening. An automatic revolver was communicated to Moses Poole, a patent agent, in 1841. The identity of the inventor of this weapon is unknown. Another automatic revolver was communicated to British patent agent William Edward Newton by the Americans Mershon and Hollingsworth in 1854.