other large possessions. From this time until the death of his father in 1608, his usual signature is "Jhone Neper, fear of Merchistoun," the word "fear" signifying holder of a fief. His first wife having died about 1579, he entered a few years afterwards into a second marriage with Agnes, daughter of Sir James Chisholm of Cromlix. His mind having been turned from an early age to the interpretation of prophecy, he was induced, through zeal for the reformation of religion in Scotland, to publish in 1593 a work entitled "A Plaine Discovery of the whole Revelation of St. John," which was held in high esteem as either the first or almost the first commentary on the Apocalypse in which a rigid and systematic method of interpretation was carried out. A new edition, augmented and improved, was published in 1611. The nature and extent of his earlier mathematical studies is proved by a fragment of a treatise on arithmetic and algebra, entitled "De Arte Logistica," which Mr. Mark Napier considers with good reason to have been composed before 1594, and which, having been preserved amongst the author's manuscripts after his death, was first printed by the Maitland Club in 1839. That fragment is sufficient of itself to place him at the head of the algebraists and philosophical arithmeticians of his time. It contains ideas upon such subjects as powers and roots, surds, negative and imaginary quantities, and the theory of equations, far in advance of the general condition of arithmetic and algebra in his age, and approaching, indeed, to those which only became common a century later. In it is anticipated the important improvement which was independently invented, and first published at a later period by Harriott, of bringing all the terms of an equation to one side, and making the result equal to 0.—(See Harriott.) It also contains a system of numerical exponents for powers and roots: a device which was not adopted by other mathematicians till long after Napier's death. Napier was the first inventor of the modern notation of decimal fractions, by the simple expedient of placing a point between the integral and fractional parts of a number. With respect to the invention of logarithms, it appears that Napier had computed tables of those quantities many years before he published them; and in particular, that a reference to the nature and use of such quantities is contained in a letter of his to Tycho Brahe, written in 1594. He then called them "artificial numbers," the word "logarithm" being an afterthought. He first published a table of logarithms, but without explaining the process whereby they had been computed, in his famous work "Mirifici Logarithmorum Canonis Descriptio," which appeared at Edinburgh in 1614, and immediately caused an extraordinary sensation in the scientific world; furnishing, as it did, the means of easily and rapidly performing computations whose previously enormous length had been an all but insurmountable barrier to the progress of astronomy. In this book Napier announced, that if it should be well received he would publish at a future time the art of computing logarithms, and some improvements in them which he had in contemplation. The celebrated Henry Briggs, one of the leading mathematicians of England, was so struck with admiration, that he undertook the then arduous adventure of a journey to Scotland, for the sole purpose of seeing the author of so wonderful a work; and thence arose a lasting friendship between those two philosophers. The logarithms in Napier's original table were those which are now called "hyperbolic;" and which are of such a nature, that the rate at which the logarithm of a given number grows or increases as compared with the rate of growth of the number itself, is the reciprocal of that number; the number whose logarithm is unity, is 2 followed by an incommensurable fraction, whose first three figures are •718; and the logarithm of 10 is 2•302, &c., another incommensurable fraction. Briggs remarked to Napier, that for arithmetical purposes it would be more convenient to have a scale of logarithms such that the logarithms of the powers of 10 should be whole numbers. Napier replied that he had been thinking of an improvement of a similar kind; and this led to the invention, by consultation between Napier and Briggs, of the "common logarithms," in which the logarithm of 10 is unity. The first table of common logarithms was computed by Briggs, and published in 1617, the year of Napier's death. Two years later, Napier's heirs received a letter from Kepler, who, not knowing of the Scottish philosopher's death, addressed to him a most enthusiastic panegyric. The last work published by Napier in his lifetime was entitled "Rabdologiæ libri duo," Edinburgh, 1617; being an explanation of the ingenious instrument for shortening calculation since known as "Napier's bones." When Britain was menaced with invasion by Spain, Napier turned his attention to the art of war, and addressed to the governments of England and Scotland a memorial, still extant in MS. at Lambeth palace, in which he offered to put the authorities in possession of several secret inventions for the defence of the country, viz., 1. A burning mirror for setting ships on fire by the sun's rays. (See Archimedes.) 2. A similar mirror for concentrating the rays of artificial fire, for the same purpose. 3. A species of artillery or missile, which, instead of flying straight onward, would range about within a limited space and destroy all therein contained. (Sir Thomas Urquhart of Cromarty alleges that he saw a successful experimental trial of this.) 4. A musket-proof chariot for soldiers. 5. A method of navigation under water. On Napier's death his scientific MSS. passed into the hands of his third son, Robert, who edited the most important of all his father's works, "Mirifici Logarithmorum Canonis Constructio," in which the theory of logarithms and the art of computing them are explained; and a very near approach is made to the method of fluxions, afterwards discovered by Newton. Annexed to this book are some highly important and useful theorems in spherical trigonometry. The rest of John Napier's scientific MSS. were long preserved by the descendants of Robert Napier (now represented by the family of Milliken-Napier); but, unfortunately, most of them were destroyed by an accidental fire at Milliken house. Amongst the ignorant of his time, Napier very naturally bore the repute of a magician, and divers marvellous feats of enchantment are ascribed to him by tradition; but his own practice of the occult sciences was limited to that of astrology, in which he seems to have been a believer, like almost all the learned and unlearned of his time. The records of his conduct in public and private affairs prove him to have had wisdom and virtue equal to his talent.—His eldest son, Archibald, first Lord Napier, was born in 1573; held office at the court of James VI. from an early age, and was one of the senators of the college of justice; he was made a peer of Scotland by Charles I. In 1596 he obtained a patent for the use of salt in fertilizing land; this is perhaps the first instance on record of the application of a chemical manure. The method to be followed is carefully described in the specification, and comprises all those precautions which are necessary in order to prevent the salt from doing harm instead of good. From him are descended the present Lord Napier, and the famous naval and military commanders of that name.—(Memoirs of John Napier of Merchiston, by Mark Napier, Esq., advocate.)—W. J. M. R.
* NAPIER, Joseph, the Right Honourable, LL.D., was born in Belfast in Ireland in December, 1804, and is descended from the Napiers of Merchiston. He received his early education from the great dramatist, James Sheridan Knowles, and was distinguished for his progress and diligence. In 1820 he entered Trinity college, Dublin, where he soon gained considerable reputation both as a classical scholar and a mathematician, obtaining honours both in classics and science during his undergraduate course. His first intention, after graduating in 1825, was to seek for a fellowship in his college, which his learning and talent would probably have secured to him; but after taking his master's degree he was induced to abandon that intention, and applied himself to study for the bar. In London he studied under Mr. Patteson, upon whose elevation to the bench in 1830 Napier commenced to practise as a special pleader. In 1831 he returned to Dublin, and was called to the Irish bar in the Easter term of that year. The following year he went to the northeastern circuit, and speedily got into good business, establishing for himself the reputation of a sound lawyer and an accurate pleader. In 1840 Napier, with some other legal friends, originated "The Law Institute," which has led to important results in the improvement of legal education in Ireland; and in this society he delivered a popular course of lectures on common law. A point of great importance was raised by Napier in 1843 in the case of the Queen v. Gray; namely, the right of persons on trial for non-capital felonies to challenge jurors peremptorily. The Irish courts decided against the right, but the house of lords, upon appeal, reversed that decision. The argument of Napier was spoken of in very favourable terms by high judicial persons in London, and established his professional reputation. Upon his return to Ireland he was called within the bar, and soon took a high place among the leading common law practitioners. He was now on several occasions engaged in appeals
