John Napier, Laird of Merchiston was a Scottish mathematician. He was born in 1550 at his family estate, Merchiston Tower, Scotland. At the age of 13 Napier attended St. Salvator's College but never graduated. In 1573 he married Elizabeth Sterling who bore him a son and a daughter before her death in 1579. A few years later he was remarried to Agnes Chisholm, whom he had five sons and five daughters with. In 1617 Napier died and is now buried in Scotland's capitol Edinburgh. John Napier is most famous for his invention of Logarithms. In his book Mirifici Logarthmorum Canonis Descriptio or Description of the Marvelous Rule of Logarithms, Napier explained How logarithms could be used for simplifying complex equations, the sole use for logarithms at his time. Napier's thinking capabilities were not limited to logarithms. He dabbled in inventing during Scottish conflict with Spain. He designed several weapons of war to aide Scotland in this conflict, including a tank-like chariot, a submarine, a burning mirror similar to that of Archimedes for setting fire to ships, and an artillery piece that could destroy a whole field of soldiers. He also came up with several novel ideas for farming, including using salt as a fertilizer and weed killer, which are still used today. Napier also wrote a book by the name of A Plaine Discovery of the Whole Revelation of John, In which he proved the Pope was the antichrist and predicted the world's end in 1700. Napier also invented a tool, called "Napier's Bones," by which multiplication and division was made easier through the arrangement of marked rods or bones to form a table.