also, who lived very near the time at which it was performed, expressly mentions Drebell's experiment, in his Mathematical Magic.' Various successful essays in subaqueous navigation, have also been made in more recent times.

It is to be lamented, that the only one of Napier's inventions, the secret of which was solicited from him by his friends when he was leaving the world, should have been that which his conscience would not allow him to reveal, for the reason that has been stated. Had they asked him to explain to them his method of sailing under the water, for example, or even the construction of his burning mirrors, he probably would have had no excuse for withholding the information. But they seem to have been so anxious to get possession of the machine for destroying the thirty thousand Turks, that they had not a thought to spare for any of the other contrivances. The circumstance, however, of some of these inventions not having been rediscovered by any one else, since Napier's time, ought not, of itself, to be taken as conclusive evidence that his pretensions to a knowledge of them were mere dreams. Extraordinary as is the progress that science has made, within the last two centuries, during which period, the conquests she has effected, have been more. numerous and wonderful than had been witnessed by all the previous centuries that had elapsed from the beginning of the world, there can be no doubt, that some of her apparently new inventions, have been only the forgotten discoveries of a preceding age revived, and also that there were some things known, in former times, which modern ingenuity has not yet recovered from oblivion. Such machines as those which Napier professes to have constructed, are exactly of the description least likely, for very obvious reasons, to occur to a modern speculator.

*For a great deal of very curious information on the lost and revived inventions of antiquity, the reader may consult G. Pasch's learned work, entitled 'De Novis Inventis quorum accuratiori cultui facem praetulit antiquitas,' of which a second edition appeared at Leipsic in 1700; or Dutens's Récherches sur l'origine des decouvertes attribuées aux modernes,' first published in 1766, and lately, for the fourth time, in 1812. Of this last work, there is an English transla tion. See also Theod. Almelobeen's Inventa Nov.-Antiqua.

In that curious record, Birrell's Diary, which was published in Edinburgh, some years ago, we find, under date of the 23d October, 1598, the following notice: 'Ane proclamation of the Laird of Merkistoun, that he tuik upon hand to make the land mair profitable nor it wes before, be the sawing of salt upon it.' There can be little doubt, we think, that this was another scheme of the inventor of the logarithms; although the patent for the new mode of manuring, appears to have been take out in the name of his eldest son, Archibald, who has been enfeofft in the fee of the barony, by his father, abo a year before. The patent, or gift of office, as it is called, was granted, upon condition that the patente should publish an account of his method in print, which, he did accordingly, shortly afterwards, under the title of The new order of gooding and manuring all sorts of field land with common salt.' This tract is now probably lost; but the facts that have been mentioned, are inter esting, as establishing Napier's claim to an agricultura improvement which has been revived in our own day, and considered.of great value. The profits of the invention were probably given up to his son, who was, at this time, a young man of only twenty-five years of age, from the same disinterested feeling which had led his father previously to enfeoff him in his estate. Devoted to his books, Napier appears to have been very indifferent about money; and one of his contemporariest even goes so far as to assert, that he dissipated his fortune by his experiments. Of this, however, there is no evidence; and the truth, in all likelihood, is merely that he bestowed but little attention upon his pecuniary concerns, occupied as his whole mind was about other matters. But if he suggested this method of manuring with salt, he must be allowed to have directed his speculations occasionally to

*See Records of Privy Council for 22d June, 1598, quoted in Douglas's Peerage, by Wood, ii. 292.

† See Parkes, on 'The advantages of using Salt.'

Thomas Dempster, a man of unquestionable learning and genius, but by no means to be always depended upon in what he states upon his own authority.

II.

6

P. K.

the improvement of the arts of common life, as well as to that of the abstract sciences.

Napier died on the 3d of April, 1617. He was twice married, and had twelve children, of whom Archibald, the eldest, mentioned above, was raised to the peerage, by the title of Lord Napier, in 1627. A small volume of Memoirs' of this person, written by himself, was published in 1793. The second part of Napier's explanation of his Logarithms was published by his third son, Robert, from his father's papers, in 1619. There are said to be still in the possession of the family, some productions of their distinguished ancestor, on scientific subjects, which have not been printed, especially, a treatise, in English, on Arithmetic and Algebra, and another, on Algebra, in Latin.*

In

The life, which we have thus sketched, may be considered as affording us an eminent example of the manner in which the many advantages enjoyed by the wealthy may be turned to account, in the pursuit of learning and philosophy. A good education, access to all the best means of improvement, uninterrupted leisure, comparative freedom from the ordinary anxieties of life, the means of engaging in inquiries and experiments, the expense of which cannot be afforded by the generality of students, -the possession of all these things, to the mind that knows how to profit by them, is indeed invaluable. We have seen what they produced, in Napier's case. dedicating his time and his fortune, to pursuits so much nobler than those that have usually occupied persons of his station, this illustrious individual had his ample reward. We can scarcely doubt that he led a happier life, in his studious retirement, in the midst of his books and his experiments, than if he had given himself either to the ordinary pleasures of the world, or to the hazards and vexations of political ambition. The more useful and more honorable path, he certainly chose. By his great and fortunate discovery, he made the science of all succeeding times his debtor, and constituted himself the benefactor of every generation of posterity. And then, for

* Douglas's Peerage, by Wood, ii. 290.

fame, which our very nature has made dear to us, that, too, this philosopher found in his closet of meditation. Even in his own day, his renown was spread abroad over Europe, and he was greeted with the publicly expressed admiration of some of the most distinguished of his contemporaries; and the time that has since elapsed, has only served to throw an increasing light around his name, which is now sure to retain its distinction so long as the sciences which he loved shall continue to be cultivated among men.

CHAPTER IV.

Drummond, of Hawthornden; Tycho Brahe; Tschirnhausen ; Boyle,―The Air-pump, and Air ;-Cavendish. NOTE.

It would be easy to add, to that of Napier, a long list of other names, of men of wealth and rank, who, in like manner, have devoted themselves to science or literature, in preference to all other pursuits. But we have space to mention only a very few. One name, which Napier's naturally suggests to us, is that of his contemporary and countryman, WILLIAM DRUMMOND, of Hawthornden, one of the most elegant poetical writers of the early part of the seventeenth century. Drummond and Napier were neighbors, but probably no record has been preserved, of any intercourse between the mathematician and the poet. As the former, however, was resorted to, every year, by his scientific English friend, Mr. Briggs; so the latter, also, had his visiter from the south, who came to pay his respects to him, from admiration of his kindred genius. In the year 1616, the famous Ben Jonson walked all the way from London to Hawthornden, to see his brother poet, and remained, for some time, as his guest. Of this visit, a curious account is preserved,

written by Drummond, himself, which has been often printed. Drummond, who was distinguished for his learning, as well as his poetry, died in 1649, in his sixtyfourth year, having lived through a very agitated period, without mixing in its political convulsions, satisfied with philosophy and the muses.

Another contemporary of Napier, whose labors and speculations were more similar to his own, was the celebrated Danish astronomer, TYCHO BRAHE. Brahe's family was both wealthy and noble; but when he first manifested his attachment to the science, in which he afterwards acquired so much reputation, being then only a boy at school, his friends did every thing they could, to check an inclination, which they deemed quite unsuited to his birth and prospects; and the young astronomer was obliged to conceal from his tutor the mathematical books, which he purchased with his pocket-money, and to read them, as well as to make his observations on the stars, in hours stolen from the time allowed him for sleep. For, even before he was sixteen, he had begun to measure the distances of the heavenly bodies from one another, although he had no better instrument than a common pair of compasses, the hinge of which he used to put to his eye, while he opened the legs until they pointed to the two stars, whose relative position he wished to ascertain. A collection of celestial observations, made by him, at this early period, is still preserved at Copenhagen.

When he became of age, however, and was his own master, his fortune enabled him to choose his own pursuits; and having first spent some years in travelling through Germany and Switzerland, and visiting the observatories in these countries, he then returned home, took up his residence on his estate, and dedicated himself, almost entirely, to his favorite science. Some of the results of his studies, which he published, soon drew to him the attention of the learned among his countrymen ; and at the desire of the king, he at last left his retreat, to teach astronomy in the capital. But the constant interruptions, to which he was here exposed, disgusted him with a town life; and he sighed to get once more back to