Napier, John, 8th Laird of Merchiston (1550-1617)

Scottish mathematician who invented logarithms 1614 and 'Napier's bones', an early mechanical calculating device for multiplication and division. It was Napier who first used and then popularized the decimal point to separate the whole number part from the fractional part of a number. Napier was born in Merchiston Castle, near Edinburgh, and studied at St. Andrews. He never occupied any professional post. English mathematician Henry Briggs went to Edinburgh in 1616 and later to discuss the logarithmic tables with Napier. Together they worked out improvements, such as the idea of using the base ten. Napier also made advances in scientific farming, especially by the use of salt as a fertilizer. In 1597 he patented a hydraulic screw by means of which water could be removed from flooded coal pits. Napier published a denunciation of the Roman Catholic Church, A Plaine Discovery of the Whole Revelation of St John 1593, as well as Mirifici logarithmorum canonis descriptio/Description of the Marvellous Canon of Logarithms 1614 and Mirifici logarithmorum canonis constructio 1619. In Rabdologiae ('numeration by little rods') 1617 he explained his mechanical calculating system and showed how square roots could be extracted by the manipulation of counters on a chessboard.