[_How to be fastened from aloof and under water._] The wording of this article so far differs from the title as to allude only to diving, or a kind of submarine navigation, but gives no intimation of the fastening “aloof;” so that this latter may refer to any part of the ship’s sides above her water-line. “Mersennius,” observes Bishop Wilkins, “doth largely and pleasantly descant concerning the making of a ship, wherein men may safely swim under water.” He further declares, that “such a contrivance is feasible, and may be effected, is beyond all question, because it hath been already experimented here in England by Cornelius Dreble.” He next considers various schemes, and mentions as one of the advantages of such a submarine vessel, that, “It may be of very great advantage against a navy of enemies, who by this means may be undermined in the water and blown up.”--Math. Magick, 1648, p. 178. Among the Sloane MSS. No. 4159, in the British Museum, is one for a means of destroying an entire fleet with one ship. It is endorsed, “A proposition sent to Mr. Augier, from Paris,” and the following is a copy:--“A person who makes profession of honour, and saith he hath had the good [fortune?] to have been known of Sir Oliver Flemming during his public employments abroad, doth propound to a friend of yours that by a secret he hath he can, with one ship alone, break what naval army or fleet, &c.” In 1596, the celebrated John Napier, of Merchiston, wrote a statement of four “Secret Inventions,” concluding with the remark: “These inventions, besides devices of _sailing under the water_, with divers other devices and stratagems for harming of the enemies, by the grace of God, and work of expert craftsmen, I hope to perform.” The original MS. anno 1596, is in the Lambeth Library, No. 658. There is an article in Tilloch’s “Philosophical Magazine,” Vol. 18, for 1804, reviewing a Memoir of Lord Napier of Merchiston. On his device for sailing under water, the writer observes:--“The famous Dutch philosopher, Cornelius Drebell, the reputed inventor of the microscope and the thermometer, constructed for James I. a subaqueous vessel, which he tried on the Thames, and which carried twelve rowers, besides some passengers, for whom the effete air was again rendered respirable by a liquor, the composition of which Drebell never would communicate to more than one person, and that person told Mr. Boyle what it was.” The Marquis, might, likewise, even be acquainted with Napier’s statement of his secret inventions.