the score of there being too many instruments of mischief in the world already for it to be the business of any good man to add to their number*. This will remind the reader of the story told respecting a machine of somewhat similar pretensions constructed at a later period by the celebrated James Gregory, of which Sir Isaac Newton, when it was shewn to him, is said to have expressed his disapprobation on the same ground, which Napier is here made to take. But the truth is, as has been often remarked, that the introduction of machines capable of producing the tremendous effects ascribed to those in question, would, in all probability, very soon put an end to war,—which has not become more destructive, but the reverse, since the invention of a more formidable artillery than that anciently in use; and which, waged with such contrivances as those of Napier and Gregory, would certainly never be resorted to by nations as a mode of settling their differences, until they had become literally insane. Another consideration, however, which might suggest itself to a man of very scrupulous feelings on such a matter, is, that it would be unfair for him to put even his native country in possession of an instrument which would, in fact, give her an advantage in her disputes with the rest of the world, against which there would be no possibility of contending. If it put an end to war, which is one great evil, it would do so by enabling a single nation to triumph over the prostration of the rest.

There appeared, some years ago, in one of our periodical works †, a very able and learned commentary on Napier's "Secret Inventions," the writer

There is a common report amongst the people at Gartness, that this machine is buried in the ground, near the site of the old castle said to have been occupied by Napier.

Tilloch's Philosophical Magazine, vol. xviii., pp. 53-65, (published Feb. 1804). See also p. 245, &c.

of which has collected, with great industry, whatever notices the annals of science afford of achievements similar to those which the Scottish mathematician is asserted to have performed. In regard to the mirror for setting objects on fire at a great distance by the reflected rays of the sun, he adduces the well-known story of the destruction of the fleet of Marcellus, at Syracuse, by the burning-glasses of Archimedes, and the other (not so often noticed) which the historian Zonaras records, of Proclus having consumed by a similar apparatus the ships of the Scythian leader Vitalian, when he besieged Constantinople in the beginning of the sixth century *. The possibility of such feats as these was long disbelieved; but may be considered as having been fully demonstrated by the experiments of modern times. Buffon, in particular, in the year 1747, by means of four hundred plane mirrors, actually melted lead and tin at a distance of fifty yards, and set fire to wood at a still greater. This, too, was in the months of March and April. With summer heat it was calculated that the same effects might have been produced at four hundred yards distance or more than ten times that to which, in all probability, Archimedes had to send his reflected rays. It may be concluded, therefore, that there is nothing absolutely incredible in the account Napier gives of his first invention. His second announcement, however, is a good deal more startling; inasmuch as he here professes to have succeeded in an attempt in which nobody else is recorded to have made any approach to success. Gunpowder has been lighted by heat from charcoal collected by one concave mirror and reflected from another; but no such effect has ever

Malala, another old chronicler, however, says that Proclus operated, on this occasion, not by burning-glasses, but by burning sulphur showered upon the ships from machines. Vid. Montucla, Histoire des Mathématiques, i. 334.

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been produced by a single reflection of artificial heat. It is not very easy to comprehend the nature of the chariot mentioned by Napier as his fourth invention; but it seems to bear some resemblance, this writer remarks, to one of the famous Marquess of Worcester's contrivances. As for the device for sailing under water, noticed in the last paragraph of the paper, that exploit was performed in Napier's own day, by the Dutch chemist Cornelius Drebell, who is reported to have constructed a vessel for king James I., which he rowed under the water on the Thames. It carried twelve rowers, besides several passengers, the air breathed by whom, it is said, was made again respirable by means of a certain liquor, the composition of which Boyle asserts in one of his publications that he knew, having been informed of it by the only person to whom it had been communicated by Drebell. Bishop Wilkins, 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 re-discovered 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*.

In that curious record, Birrell's Diary, which was published in Edinburgh some years ago, we find, under date of the 23rd 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 taken out in the name of his eldest son, Archibald, who had been

* 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 Leipsick in 1700; or Dutens's "Récherches sur l'origine des découvertes attribuées aux modernes," first published in 1766, and lately for the fourth time in 1812. Of this last work there is an English translation, See also Theod. Almelobeen's Inventa Nov.-Antiqua.

infeft in the fee of the barony by his father about a year before*. The patent, or gift of office, as it is called, was granted upon condition that the patentee 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 interesting as establishing Napier's claim to an agricultural 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 contemporaries ‡ 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 the improvement of the arts of common life, as well as to that of the abstract sciences.

Napier died on the 3rd of April, 1617. He was twice married, and had twelve children, of whom Archibald, the eldest, mentioned above, was raised to

See Records of Privy Council for 22nd 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.