The Arithmographe

An Early Example Of A Portable Calculator

More than three centuries ago, the Parisian physician and polymath Claude Perrault devised a fascinating small mechanic calculator, Abaque Rhabdologique. Subsequently, many mathematicians and inventors have improved, and re-shaped, Perrault's ingenius machine.
As an heir of this tradition, Troncet created what he called the Arithmographe. Essentially, it is a small stylus-driven metal calculator consisting of flat metal bands with notched edges pointing at numbers from one to nine.