1820 – Arithmometer sees light as first mass-produced calculator

In 1820 The Arithmometer (or Arithmomètre)  was the first mass-produced calculator invented by Charles Xavier Thomas de Colmar. It was  a mechanical calculator that in addition to adding and subtracting could also perform long multiplications and divisions. These calculations were achieved by using a movable accumulator, patented in France by Thomas de Colmar. He made use of principles from previous mechanical calculators like the stepped reckoner of Leibniz and Pascal’s Calculator – Pascaline. Thomas de Colmar patented his invention on November 18, 1820.Between 1851 and 1915 it was hugely successful as first commercial mechanical calculator, and until 1887 the Arithmometer was the only type of mechanical calculator that was sold worldwide. Later, other companies started copying the Arithmometer: German Burkhardt (1878 ) and British Layton (1883). This number grew to almost two dozen by the middle of the 20-th century.

The first machine was built by Devrine, a Parisian clockmaker during a course of a full year. He modified original design to make it work.

The original Arithmometers from the period of 1820 to 18951 were four-operation devices. It was a complicated design that was keeping the machines from being mass-produced. In 1851, the multiplier was removed, making an Arithmometer a much simpler machine with yet powerful ability to multiply and divide easily using a moving carriage as indexed accumulator. This adjustment allowed for an easier industrial production of the calculating machines from 1851 going forward.

Because it was the first mass marketed and produced for the public, and the first widely cloned calculator, its invention and design mark the beginning of the industrial mechanical calculator history.  It eventually morphed into the electronic calculator industry and further to the first commercially available personal computer.