Mechanical calculators
Leonardo da Vinci (end of the 15th century)
Wilchelm Schickard (1623)—the Calculating Clock
Blaise Pascal (1642)—the Pascaline
Tito Livio Burattini (1659)
Samuel Morland (1669)
Claude Perrault (about 1670)
Gottfried Wilhelm Leibniz (1672)—the Stepped Reckoner
René Grillet de Roven (1678)