The pioneers

Some of the greatest people in European scientific history are involved in this affair. There are other, who attempted to create such devices, but almost nothing had survived to our time, like the Dutch Jesuit-mathematician Johann Ciermans (1602-1648), who mentioned in a 1640 book, Annus positionum mathematicarum, that he created a mechannical calculator with wheels, suitable for multiplication and division.

Leonardo da Vinci (1493)

Wilchelm Schickard (1623)—the Calculating Clock

Blaise Pascal (1642)—the Pascaline

Tito Livio Burattini (1659)

Samuel Morland (1669)

Claude Perrault (around 1670)

Gottfried Wilhelm Leibniz (1672)—the Stepped Reckoner

René Grillet de Roven (1678)

Since we cannot know all that there is to be known about anything, we ought to know a little about everything.
Blaise Pascal