NAPIER, or NEPER, JOHN, Baron of Merchistoun, the celebrated inventor of the Logarithms, was the eld est son of Sir Archibald Napier of AIerchistottn, Alaster of the Mint in Scotland, and was born at Merchistoun in the year 1550. Having given early indications of in dustry and talents, his education was conducted with great care, and, after going through the ordinary course of study at the college of St. Andrew's, Ile made the tour of the Low Countries, France, and Italy, where he is said to have applied himself to the mathematics. On his return from the continent, he devoted himself in a particular manner to the study of geometry and the Scriptures ; and, in the year 1593, he published his es say on the Apocalypse, under the title of A Plain Dis covery of the Revelation of St. John. This work gained our author great reputation, and was translated into se veral foreign languages.
In the year 1596, Napier wrote a letter, addressed to Anthony Bacon, (the original of which is in the Atch bishop of Canterbury's library at Lambeth,) entitled, " Secret inventions necessary in these days for the de fence of this island, and withstanding strangers, enemies to God's huth and religion." * The attention of Baron Napier was about this time engrossed by his discovery of logarithms. Having oc casion, from his attachment to astronomy, to make many numerical calculations in spherical trigonometry, he set himself to find out some method of diminishing the la bour of calculation. Wood informs us, in the Atlienic Oxoniensis, on the authority of Oughtred and Wingate, 6 6 that one Dr. Craig, a Scotchman, coming out of Den mark into his °Iv') country, callcd upon John Napier, Baron of Marcheston, near Edinburgh, and told him, among other discourses, of a new invention in Denmalk, (by Longomontanus, as 'tis said') to save the tedious multiplication and division in astronomical calculations. Napier being solicitous to know farther of him concern ing this matter, he could give no other account of it than that it W3S by proportionable numbers. Which hint Napier taking, he desired him at his return to call upon him again. Craig, after some weeks had passed, did so, and Napier 'hen showed him a rude draught of what he called Ca,. Mirabilis Logaritlimorunt; which draught, with some alterations, he printed in 1614. It came forth into the hands of our author Briggs, and into those of William Oughtred, from whom the relation of this matter came." Although there seems to be no reason for doubting these facts, yet, excepting the remark that Napier took the hint from his conversation with Dr. Craig, they are In no respect inconsistent with the statement made in the preface to Napier's work, where it appears that he NV S led to the investigation from the difficulties whieh Ile had experienced in his trigonometrical calculations.
The work, which contained this great invention of ar tificial numbers for abridging calculation, appeared in 1614, under the title of Los-arithmorum Canonis Descrifi tio, of which we have already given a particular account, together with Dr. Briggs's improvements, in our article on LOGARITHMS.
In consequence of the correspondence which took place between these eminent men, the Baron seems to have in vited Briggs to visit him in Scotland. " Napier, Lord of Merchistoun," says Briggs, in a letter to Archbishop Usher, dated Alarch 10, 16 t 5, " bath set every head and hand at work with his new and admirable logarithms. I hope to see him this summer, if it please God ; for I never saw a book which pleased me better, and made me more wonder." Briggs accordingly made him a month's visit, of which the following curious account is given in the life of Lilly the astrologer.
" I will acquaint you (says Lilly) with one memorable story, related unto me by John Marr, an excellent ma thematician and geometrician, whom I conceive you re member. He was servant to king James I. and Charles
I. When Merchistoun first published his logarithms, Mr. Briggs, then reader of the astronomy lectures at Gresham college in London, was so surprised with ad rniration of them, that he could have no quietness in him self until he had seen that noble person, whose only invention they wcre ; he acquaints John Marr therewith, who went into Scotland before Mr. Briggs, purposely to 'te there when these two so learned persons should meet. Mr. Briggs appoints a certain day when to meet at Edin burgh ; but railing' thereof, Merchistoun was fearful he would not come. It happened, one day, as John Marr and the Lord Napier were speaking of Mr. Briggs; 4 Ah, John, (saith Merchistoun)Mr. Briggs will not now come ; zt the very instant one knocks at the gate ; John Marr hasted down, and it proved to be Alr. Briggs, to his great contentment. He brings Mr. Briggs up into my Lord's chamber, where almost one quarter of an hour was spent, each beholding other with admiration before one word was spoken. At last Mr. Briggs began. g My Lord, I have undertaken this long journey, purposely to see your person, and to know by what engine or wit or ingenuity you came first to think or this most excellent help unto astronomy, viz. the logarithms ; but, my lord, being by you found out, I wonder no body else found it out befoce, when now, being known, it appears so easy.' He was nobly entertained by the Lord Napier, and every summer after that, during the Laird's being alive, this venerable man, Mr. Briggs, went purposely to Scotland to visit him." Besides his great invention of the logarithms, Baron Napier improved trigonometry with his universal rules or theorems for solving all the cases of right angled sphe rical triangles, which he calls thedive circular fiarts, and of which we shall have occasion to give an account in our article on TRIGONOMETRY. The last production of this eminent mathematician was his Rabdologia, seu numera tionis fier Virgulas, Libri Duo, which appeared in 1617, and which was dedicated to the Chancellor Seton. This work contains the description and use of an apparatus, called Napier's Bones or Rods, and other ingenious me thods of abridging calculation. The description of the Bones Will be found in our article ARIl Hmeric. Napier did not long. survive tile publication of this work. He died at Aferchistoun on the 3d April, O. S. 1617, in the 68t'n year of his age ; and such was the extent of his re putation, that the illustrious Kepler dedicated to him his Ephemerides, which were published in 1617 ; and it ap pears from many passages in his letter, that he reckoned Napier the greatest man of his age in the particular de partment to which he had directed his attention. He was buried in the cathedral church of St. Giles, on the east ern side of its northern entrance, where a stone tablet, bearing a Latin inscription, indicates that this is the burial place of the Napiers.
Baron Napier of Alerchistoun was twice married. He had only one son, called Archibald, by his first wife, who was a daughter of Sir James Sterling of Keir. By his second wife, a daughter of Sir James Chisholm of Crombie, Ile had a numerous family, of five sons and five daughters. His eldest son Archibald, who attained to eminence in his father's lire time, was made a privy counsellor by James VI., in whose reign Ile held the se veral offices of treasurer-depute, justice-clerk, and sena tor of the College of Justice ; and he was raised by Charles I. in 1627, to the peerage, by the title of Lord Napier. His third son was a pupil of his own in mathe matics, and to him he bequeathed the care of publishing his posthumous works.
For farther information respecting the life and writings of that eminent individual, see The account of the Life, Trritings, and Inventions of John A^apier of .ilIerchiston, by the Earl of Buchan. Perth, 1787.