The book of science

Tom Sharp

John Napier mathematics


Proportional numbers


Decimal arithmetic was explained by Simon Stevin in 1585, but Stevin’s notation, lacking the decimal point, was cumbersome. The decimal point was introduced by Bartholomaeus Pitiscus, then adopted and taught by John Napier. The popularity of logarithms made its use common.

John Napier also invented a calculating aid in 1617 known as “Napier’s bones.” Only five years later, in 1622, William Oughtred created the first slide rule, an analog calculator based on logarithmic scales. Blaise Pascal invented the mechanical calculator, known as the “Pascaline,” in 1645. Charles Babbage’s Difference Engine, in 1822, was a more complex mechanical calculator, but was controlled by programs stored on punch cards, like the first computers.

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