2OO in the county of Edinburgh, was master of the mint to James VI., and was only sixteen years of age when the subject of this memoir was born. The mother of the inventor of the logarithms was Janet, only daughter of Sir Francis Bothwell, a lord of ses- sion, and sister of Adam, Bishop of Orkney. There is a prevalent notion that the inventor of the lo- garithms was a nobleman: this has arisen from his styling himself in one of his title-pages Baro Merchis- tonii; in reality, this implied baron in the sense of a superior of a barony, or what in England would be called lord of a manor. Napier was simply laird of Merchiston—a class who in Scotland sat in par- liament under the denomination of the lesser barons. Napier was educated at St. Salvator's College in the university of St. Andrews, which he entered in 1562. He afterwards travelled on the Continent, probably to improve himself by intercourse with learned and scientific men. Nothing further is as- certained respecting him till after he had reached the fortieth year of his age. He is then found settled at the family seats of Merchiston near Edinburgh, and Gartness in Stirlingshire, where he seems to have practised the life of a recluse student, without the least desire to mingle actively in political affairs. That his mind was alive, however, to the civil and religious interests of his country is proved by his pub- lishing in 1593 an exposition of the Revelations, in the dedication of which to the king he urged his majesty, in very plain language, to attend better than he did to the enforcement of the laws and the pro- tection of religion, beginning reformation in his own "house, family, and court." From this it appears that Napier belonged to the strict order of Presby- terians in Scotland; for such are exactly the senti- ments chiefly found prevalent among that class of men at this period of our history. In the scantiness of authenticated materials for the biography of Napier, some traditionary traits become interesting. It is said that, in his more secluded residence at Gartness, he had both a waterfall and a mill in his immediate neighbourhood, which con- siderably interrupted his studies. He was, however, a great deal more tolerant of the waterfall than of the mill; for while the one produced an incessant and equable sound, the other was attended with an irregular clack-clack, which marred the processes of his mind, and sometimes even rendered it necessary for him, when engaged in an unusually abstruse cal- culation, to desire the miller to stop work. He often walked abroad in the evening in a long mantle, and attended by a large dog; and these circumstances working upon minds totally unable to appreciate the real nature of his researches, raised a popular rumour of his being addicted to the black art. It is certain that, no more than other great men of his age, was he exempt from a belief in several sciences now fully proved to have been full of imposture. The practice of forming theories only from facts, however reason- able and unavoidable it may appear, was enforced only for the first time by a contemporary of Napier —the celebrated Bacon; and, as yet, the bounds be- tween true and false knowledge were hardly known. Napier therefore practised an art which seems nearly akin to divination, as is proved by a contract entered into in 1594 between him and Logan of Fastcastle— afterwards so celebrated for his supposed concern in the Gowrie Conspiracy. This document states it to have been agreed upon, that, as there were old re- ports and appearances that a sum of money was hid within Logan's house of Fastcastle, John Napier should do his utmost diligence to search and seek out, and by all craft and ingine [a phrase for mental power] to find out the same, or make it sure that no such thing has been there. For his reward he was to have the exact third of all that was found, and to be safely guarded by Logan back to Edinburgh; and in case he should find nothing, after all trial and diligence taken, he was content to refer the satisfac- tion of his travels and pains to the discretion of Logan. What was the result of the attempt, or if the attempt itself was ever made, has not been ascer- tained. Besides dabbling in sciences which had no founda- tion in nature, Napier addicted himself to certain speculations which have always been considered as just hovering between the possible and the impossible, a number of which he disclosed, in 1596, to Anthony Bacon, the brother of the more celebrated philoso- pher of that name. One of these schemes was for a burning mirror, similar to that of Archimedes, for setting fire to ships; another was for a mirror to produce the same effects by a material fire; a third for an engine which should send forth such quanti- ties of shot in all directions as to clear everything in its neighbourhood; and so forth. In fact, Napier's seems to have been one of those active and excursive minds, which are sometimes found to spend a whole life in projects and speculations without producing a single article of real utility, and in other instances hit upon one or two things, perhaps, of the highest order of usefulness. As he advanced in years he seems to have gradually forsaken wild and hopeless projects, and applied himself more and more to the useful sciences. In 1596 he is found suggesting the use of salt in improving land—an idea probably passed over in his own time as chimerical, but re- vived in the present age with good effect. No more is heard of him till, in 1614, he astonished the world by the publication of his book of logarithms. He is understood to have devoted the intermediate time to the study of astronomy—a science then reviving to a new life under the auspices of Kepler and Galileo, the former of whom dedicated his Ephemerides to Napier, considering him as the greatest man of his age in the particular department to which he applied his abilities. "The demonstrations, problems, and calculations of astronomy most commonly involve some one or more of the cases of trigonometry, or that branch of mathematics which, from certain parts, whether sides or angles, of a triangle being given, teaches how to find the others which are unknown. On this account trigonometry, both plane and spherical, engaged much of Napier's thoughts; and he spent a great deal of his time in endeavouring to contrive some methods by which the operations in both might be facilitated. Now, these operations the reader, who may be ignorant of mathematics, will observe always proceed by geometrical ratios or proportions. Thus, if certain lines be described in or about a triangle, one of these lines will bear the same geometrical pro- portion to another as a certain side of the triangle does to a certain other side. Of the four particu- lars thus arranged three must be known, and then the fourth will be found by multiplying together certain two of those known, and dividing the pro- duct by the other. This rule is derived from the very nature of geometrical proportion, but it is not necessary that we should stop to demonstrate here how it is deduced. It will be perceived, however, that it must give occasion, in solving the problems of trigonometry, to a great deal of multiplying and dividing—operations which, as everybody knows, become very tedious whenever the numbers concerned are large, and they are generally so in astronomical calculations. Hence such calculations used to exact immense time and labour, and it became most im-