Humanities › History & Culture John Napier - Napier's Bones John Napier 1550 - 1617 Share Flipboard Email Print Kim Traynor / Getty Images History & Culture Inventions Famous Inventors Famous Inventions Patents & Trademarks Invention Timelines Computers & The Internet American History African American History African History Ancient History and Culture Asian History European History Genealogy Latin American History Medieval & Renaissance History Military History The 20th Century Women's History View More By Mary Bellis Inventions Expert Mary Bellis covered inventions and inventors for ThoughtCo for 18 years. She is known for her independent films and documentaries, including one about Alexander Graham Bell. our editorial process Mary Bellis Updated April 06, 2017 The hand without a thumb is at worst nothing but an animated spatula and at best a pair of forceps whose points don't meet properly - John Napier 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 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. 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. Napier's Bones Napier's bones were multiplication tables written on strips of wood or bones. The invention was used for multiplying, dividing, and taking square roots and cube roots.