John Napier, laird of Merchiston, the inventor of logarithms, born at Merchiston castle, near Edinburgh, in 1550, died there, April 4, 1617. In 1562 he entered St. Salvator's college in the university of St. Andrews, and subsequently passed several years in travelling in France, Italy, and Spain. On his return to his native country he did not mingle in active life, and but little is known of him until he had arrived at the age of 40. In 1593 he published "A Plain Discovery of the Revelation of St. John " (4to, Edinburgh), and in the dedication gave King James some advice in regard to religious matters, and the propriety of reformation in his own " house, family, and court." A letter of his to Anthony Bacon, concerning secret inventions for national de-fence, written in 1596, still exists in the archbishop's library, Lambeth. One of these was for a burning mirror to set fire to ships by reflecting the rays of the sun; another was a device to accomplish the same purpose by reflecting "the beams of any material fire or flame;" another an instrument which should scatter such an amount of shot in all quarters as to destroy everything near it.
Nothing is heard of him after this until in 1614 he brought out his system of logarithms, entitled Mirifici Logarithmorum Ganonis Descriptio (4to, Edinburgh). Although published then, it is evident that Napier had begun the investigation of this subject before 1594, from a letter written by Kepler to Crugerus in 1624, in which he says: Nihil autem Nepierianam rationem esse puto; etsi Scotus quidem Uteris ad Tychonem, anno 1594, scriptis jam spem fecit canonis illius mirifici. No sooner was the work published than Henry Briggs, then professor of mathematics in Gresham college, London, began the application of the rules in his Imitatio Nepierea, and the system proposed by him is now commonly used. Napier's last work was his Llabdologioe seu Numevatio-v is per Virgulas Libri duo (12mo, Edinburgh, 1617), in which he explained a contrivance to facilitate multiplication and division by means of small rods, which invention goes under the name of Napier's bones. After his death was published his Mirifici Logarithmorum Canonis Constructio (12mo, 1619), in which he explained the principle of the construction of logarithms. Napier also enriched the science of trigonometry by the general theorem for the resolution of all the cases of right-angled spherical triangles.
There are two lives of Napier: one by the earl of Buchan, with an analysis of his works by Dr. Walter Minto (1787), and another by Mark Napier (1834).