John Napier was a Scottish mathematician and inventor. Napier is famous for creating mathematical logarithms, creating the decimal point, and for inventing Napier's Bones, a calculating instrument.

### John Napier - Inventor

While better known as a mathematician, John Napier was a busy inventor. He proposed several military inventions including: burning mirrors that set enemy ships on fire, special artillery that destroyed everything within a radius of four miles, bulletproof clothing, a crude version of a tank, and a submarine-like device. John Napier invented a hydraulic screw with a revolving axle that lowered water levels in coal pits. Napier also worked on agricultural innovations to improve crops with manures and salt.### John Napier - Mathematician

As a Mathematician, the highlight of John Napier's life was the creation of logarithms and the decimal notation for fractions. His other mathematical contributions included: a mnemonic for formulas used in solving spherical triangles, two formulas known as Napier's analogies used in solving spherical triangles, and the exponential expressions for trigonometric functions.In 1621, English mathematician and clergyman, William Oughtred used Napier's logarithms when he invented the slide rule. Oughtred invented the standard rectilinear slide rule and circular slide rule.