[997]. Οὓς δὲ καλοῦσιν εὐθὺς ἄνθρακας τῶν θρυπτομένων διὰ τὴν χρείαν, εἰσὶ γεώδεις· ἐκκαίονται δὲ καὶ πυροῦνται καθάπερ οἱ ἄνθρακες. Εἰσὶ δὲ περί τε τὴν Λιγυστικὴν, ὅπου καὶ τὸ ἤλεκτρον, καὶ ἐν τῇ Ἠλεία βαδιζόντων Ὀλυμπίαζε τὴν δι’ ὄρους, οἷς καὶ οἱ χαλκεῖς χρῶνται. Theoph. de Lapid. § 16.
[998]. Annot. ad Theoph. iv. 552. Xen. Anab. v. 3. 10. Strab. viii. p. 145. Sieb.
[999]. Plat. de Repub. t. vi. p. 194.
[1000]. Theoph. Hist. Plant. v. 9. 4, sqq.
[1001]. Aristoph. Nub. 758. Cf. Orph. Lith. 171. p. 111.
[1002]. Athen. i. 35.
CHAPTER V.
INDUSTRY: HOUSE-BUILDERS, CARPENTERS, CABINET-MAKERS, TURNERS, MUSICAL INSTRUMENT-MAKERS, POTTERS, GLASS-WORKERS, ETC.
Another flourishing branch of industry was that of quarrying stones for building, carried on wherever marble, or freestone, or tufa, or granite, was found.[[1003]] The stones were usually fashioned by the axe, or saw,[[1004]] in the quarry, and drawn thence by ropes. In many cases, however, as where cheapness or despatch was aimed at, bricks were substituted,[[1005]] made, in addition to the materials at present employed, from powdered tufa.[[1006]]
In the preparation of mortar and cement the Greeks exhibited extraordinary ingenuity.[[1007]] They made use, in the first place, of lime procured by burning coarse marble in the ordinary way, or, secondly, obtained from sea-shells, or stones picked up on the banks of rivers. A superior kind of cement was made from those stones used in the manufacture of gypsum, which was so firm and durable, that it was frequently found to outlast the materials which it had been employed to unite. It was prepared by being reduced to powder, and mixed with water, and afterwards well stirred with a piece of wood, since it was too hot to admit of the hands being used. When removed from old walls it might be burnt and prepared a second and a third time, as originally from the stone.[[1008]] This, in Syria and Phœnicia, was used in facing the walls of houses, and in Italy for whitening them, as well as in the making of various mouldings and ornaments within.[[1009]]