A History of Inventions, Discoveries, and Origins (Vol. 1&2). Johann Beckmann

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СКАЧАТЬ 3. The same account is given by Arrian, De Expedit. Alexandri, lib. ii. p. 138. We are told by Thucydides, in his seventh book, that the Syracusans did the same thing.

279 Boerhaave, Prælectiones Academicæ, edit. Halleri, Göttingæ, 1774. 8vo, v. ii. p. 472–474. Halleri Elementa Physiologiæ, iii. p. 252, and viii. 2, p. 14.

280 “The divers of Astracan stepped from the warm bath into the water, in which they could not continue above seven minutes, and were brought back from the water, cold and benumbed, to the warm bath, from which they were obliged to return to the water again. This change from heat to cold they repeat five times a day, until at length the blood flows from their nose and ears, and they are carried back quite senseless.”—Gmelin’s Reise durch Russland, ii. p. 199.

281 Acta Philosophica Societatis in Anglia, auctore Oldenburgio. Lipsiæ, 1675, 4to, p. 724.

282 Scheeps-bouw beschreven door Nic. Witsen. Amsterdam, 1671, fol. p. 288.

283 [See the account of the Ceylon pearl fishery in Percival’s Ceylon.]

284 “Were the ignorant vulgar told that one could descend to the bottom of the Rhine, in the midst of the water, without wetting one’s clothes, or any part of one’s body, and even carry a lighted candle to the bottom of the water, they would consider it as altogether ridiculous and impossible. This, however, I saw done at Toledo, in Spain, in the year 1538, before the emperor Charles V. and almost ten thousand spectators. The experiment was made by two Greeks, who taking a very large kettle, suspended from ropes with the mouth downwards, fixed beams and planks in the middle of its concavity, upon which they placed themselves, together with a candle. The kettle was equipoised by means of lead fixed round its mouth, so that when let down towards the water no part of its circumference should touch the water sooner than another, else the water might easily have overcome the air included in it, and have converted it into moist vapour. If a vessel thus prepared be let down gently, and with due care, to the water, the included air with great force makes way for itself through the resisting fluid. Thus the men enclosed in it remain dry, in the midst of the water, for a little while, until, in the course of time, the included air becomes weakened by repeated aspiration, and is at length resolved into gross vapours, being consumed by the greater moisture of the water: but if the vessel be gently drawn up, the men continue dry, and the candle is found burning.”—Taisneri Opuscula de celerrimo motu, quoted by Schott in his Technica Curiosa, lib. vi. c. 9, p. 393.

285 “Excellent use may be made of this vessel, which is employed sometimes in labouring under water on sunk ships, to enable the divers to continue longer under water, and to breathe, in turns, for a little while. It was constructed in this manner. A hollow vessel was made of metal, which was let down equally to the surface of the water, and thus carried with it to the bottom of the sea the whole air it contained. It stood upon three feet, like a tripod, which were in length somewhat less than the height of a man; so that the diver, when he was no longer able to contain his breath, could put his head into the vessel, and, having breathed, return again to his work.”—Novum Organum, lib. ii. § 50. Bacon relates the same thing in his Phænomena Universi.

286 G. Sinclari Ars nova et magna gravitatis et levitatis. Rot. 1669, 4to, p. 220.

287 Paschii Inventa nov-antiqua. Lipsiæ, 1700, 4to, p. 650.

288 Theatri Statici universalis pars tertia. Lipsiæ, 1726, fol. p. 242.

289 This account is taken from the History of the British Empire in America, by J. Wynne. London, 1770, 2 vols. 8vo, i. p. 131, and from Campbell’s Lives of the Admirals.

290 Martin’s Description of the Western Islands. The second edition. London, 1716, 8vo, p. 253.—Campbell’s Political Survey of Britain. London, 1774, 2 vols. 4to, p. 604.

291 These figures are to be found in the following editions of Vegetius:—Lutetiæ apud C. Wechelum, 1532, fol. p. 180. Fegetius, vier Bücher von der Rytterschafft. Erfurt, Hans. Knappen, 1511, fol. These figures are inserted also in Leupold’s Theatrum Pontificale, p. 11, tab. ii. fig. 6.

292 Le Fortificationi di Bounaiuto Lorini. Venet. 1609, fol. p. 232.

293 Fran. Kessleri Secreta. Oppenheim, 1617, 8vo.

294 Bartholini Acta Hafn. 1676, p. i. obs. 17.

295 Scheeps-bouw, ut supra.

296 See vol. i. p. 222, edit. Hag. Com. 1743.

297 Acta Eruditorum, 1683, Decemb. p. 553. Jac. Bernoulli Opera.

298 Phil. Trans. 1736.—Martin Triewald’s Konst at lefwa under watnet. Stockholm, 1741, 4to.

299 Brewster’s Edinburgh Encyclopædia, Art. Diving-bell.

300 Reports of the late John Smeaton, F.R.S., vol. iii. p. 279.

301 Phil. Trans. 1717 and 1721. The art of living under water, by Halley.

302 Martin’s Philosophia Britannica, vol. iii. p. 180.

303 For further information on this important subject the reader is referred to the article Diving-bell in the Encyclopædia Britannica and its Supplement, also the Encyclopædia Metropolitana, Brewster’s Edinburgh and the Penny Cyclopædia, Halley’s papers in the Phil. Trans. for 1716 and 1721, Triewald’s in the same for 1736, Healy in the Philosophical Magazine, vol. xv., and Leopold’s Theatrum Machinarum Hydraulicarum.

      COLOURED GLASS.—ARTIFICIAL GEMS.

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It is probable that there was no great interval between the discovery of the art of making glass, and that of giving it different colours. When the substance of which it is formed contains, by accident, any metallic particles, the glass assumes some tint; and this happens СКАЧАТЬ