These small, flat calculators have a long history.
The Frenchman Caze (1720) and the Russian Kummer (1847) build the first calculators based on this principle.
In 1888 J.L.Troncet (France) produced the Arithmographe. That is the reason why they give this kind of calculators the name troncets.
These troncets are produced in several countries (Germany, USA, Japan) until the introduction of the electronic pocketcalculator.