Footnote 850: Theoph. de Lapid. § 32. ----- Respecting the various processes by which precious stones were engraved, the ancients have left us but a few scattered hints. It appears certain, however, that they polished precious stones with emery,[851] and possessed the lapidary’s wheel, with all the finer tools at present in use, including the diamond point,[852] which there is reason to believe they likewise fixed on the wheel.[853] At any rate, they contrived with the instruments they possessed to engrave figures, as of lions, heroes, bacchantes, caryatides, trophies,[854] both in relief and intaglio, which for beauty and delicacy have never yet been equalled. It was at one time a question whether or not they were acquainted with the microscope,[855]—though how they could engrave without it figures which we require its assistance distinctly to perceive, seems somewhat difficult to comprehend. The gem, for example, called the seal of Michael Angelo, in the French king’s cabinet, though it does not exceed half an inch in diameter, contains fifteen figures most elaborately wrought.[856] A private gentleman at Rome possessed a wolf’s tooth on which was a representation of the twelve gods.[857] Cicero commemorates an individual who had written the whole Iliad in characters so minute and in so small a compass, that it could be contained in a walnut-shell.[858] Myrmecides, the Milesian, and Callicrates, the Lacedæmonian, manufactured ivory chariots so small, that they could be covered with the wing of a fly; and wrote two verses in gold letters on a grain of sesame.[859] ----- Footnote 851: Σμύρις λίθος ἐστιν, ᾗ τὰς ψήφους οἱ δακτυλιογλύφοι σμήχουσι. Dioscor. v. 166. Footnote 852: Plin. Nat. Hist. xxxvii. 15, with the authors cited by Hardouin. Footnote 853: Winkelm. Hist. de l’Art. t. ii. p. 108. Footnote 854: Plut. Alexand. § 1. Timol. § 31. Herod. iii. 41. Footnote 855: Cf. Senec. Quæst. Nat. i. 6. Macrob. Saturn. viii. 14. Footnote 856: Dutens, Origine des Découvertes, &c. p. 265. Footnote 857: Winkelm. Hist. de l’Art. t. i. p. 36. n. 4. Footnote 858: Plin. Hist. Nat. vii. 21. Footnote 859: Ælian. Var. Hist. i. 17. ----- We find mention, however, of burning-glasses as early as the age of Socrates;[860] and a number of lenses, more powerful than those employed by our own engravers, have been found among the ruins of Herculaneum.[861] We may here, also, remark by the way, that the Greek astronomers appear to have been acquainted with the telescope.[862] ----- Footnote 860: Aristoph. Nub. 764, seq. Cf. Aristot. Analyt. Post. i. 31. 8. Barthelémy St. Hilaire de la Logique d’Aristot. t. ii. p. 367. Footnote 861: Dutens, Origine des Découvertes, &c. p. 265. i. Footnote 862: Id. p. 115, seq. Nixon. in Phil. Trans. v. lii. p. 125. ----- CHAPTER IV. INDUSTRY: SMITHS, CUTLERS, ARMOURERS, THE ART OF MINING, CHARCOAL-MAKING, ETC.