Over the centuries, people have applied themselves to the art of calculating – executing operations on numbers. This was not always easy; it cost a lot of time, and the result was not always satisfactory. A wide array of aids were used, to allow for simpler, faster, and more reliable calculation. Many of these calculating aids owed their success to being better at one of these aspects. The inventor of a particular calculating aid, or its improvement, was frequently motivated by the promise of commercial recognition or monetary reward. As such, competition between inventors was fierce, sometimes even leading to legal battles over patents. But such competition, driven by the demand for innovation in calculation, led to interesting developments and variations in calculating aids.

In this exhibition, we gathered a selection of calculating apparatus, and the fascinating stories that go with them. The starting point is of course the first mechanical "calculating clock" by Wilhelm Schickard (1623), which celebrates its 400th anniversary this year. We use this first calculator as the starting point for a series of stories - from the centuries before the invention of the Schickard calculating clock, up to the last century.

de rekenklok van Schickard

Enjoy this virtual exhibition!

Cris, Paul and Erwin

Flag Counter free counters