Computing · 1694

Stepped reckoner

Leibniz's machine that could multiply, thanks to the stepped drum.

Gottfried Leibniz designed the machine in 1672 and completed it in 1694. Its stepped drum mechanism became the core of nearly every commercial mechanical calculator for the next 250 years.

See it in the living tree Wikipedia

Arcs above join it to what it stood on, arcs below to what it led to. The bar places this stretch on the tree's whole timeline.

What it built on 1

Pascaline 1642

What it led to 2

Difference engine 1822
Arithmometer 1851

Related measurements

The dashed line marks when it first worked.

Computation per constant dollar, 1850-2006 Latest: 7.3B million units of computer power per 2006 $ (2003) Source: Nordhaus 2007, Two Centuries of Productivity Growth in Computing, J. Econ. Hist. 67(1), Table 6