Napier, John

Napier, John, 1550–1617, Scottish mathematician. He invented logarithms and wrote Mirifici logarithmorum canonis descriptio (1614), containing the first logarithmic table and the first use of the word logarithm. His Rabdologiae (1617) gives various methods for abbreviating arithmetical calculations. One method of multiplication uses a system of numbered rods called Napier's rods, or Napier's bones; this was a major improvement on the ancient system of counters then in use. In 1619, after Napier's death, his Mirifici logarithmorum canonis constructio, which gave the method of construction of his logarithms, was published by his son Robert and edited by Henry Briggs. Napier introduced the decimal point in writing numbers. Napier was also known as an outspoken exponent of the Protestant cause. His religious writings include A Plaine Discovery of the Whole Revelation (1593), the earliest Scottish interpretation of the scriptures.

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Napier, John

(born 1550, Merchiston Castle, near Edinburgh, Scot.—died April 4, 1617, Merchiston Castle) Scottish mathematician and champion of Protestantism. He divided his life between attacks on the church of Rome and the pursuit of numerical calculations. On a number of occasions he urged James IV of Scotland to deal firmly with the Catholic threat. From 1594 he worked on developing secret weapons, including a metal chariot with small holes through which shot could be fired. He developed the concept of the logarithm to facilitate calculations involving multiplication, division, roots, and powers. He also introduced the decimal point as a notation for decimal fractions. The set of calculating rods he designed was a precursor to the slide rule.