The Scottish mathematician John Napier (1550-1617) discovered logarithms and effectively introduced the modern notation of decimal fractions.

John Napier, or Neper, the son of Sir Archibald Napier, was born at Merchiston Castle near Edinburgh. At the age of 13 he entered the University of St. Andrews. He might also have studied at universities in the Low Countries, France, and Italy. What is known with certainty is that by 1571 Napier was back home and the next year married Elizabeth Stirling. His life at the newly built castle at Gartnes left him with ample time for such varied interests as mathematics, agriculture, and religious politics.

A Calvinist resolved to keep Catholicism out of Scotland at any price, Napier rallied against the conspiracy known as the Spanish Blanks with a book, A Plaine Discovery of the Whole Revelation of St. John (1594). To make the resistance more effective, he devised four new weapons...