quainted with one capable of producing on that stone, which they considered as a species of marble, the same effects as an acid does on the latter. But Vasari says nothing of the kind,

After Tadda's death, the art of cutting porphyry came to Raphael Curradi, who communicated to Dominico Corsi this secret, which was afterwards employed by Cosimo Silvestrini.* I, however, agree in opinion with Winkelman and Fiorillo, our learned connoisseur in the arts, that the method of working porphyry was known in every age, and even in the most barbarous, though artists, no doubt, preferred working on other stones which were less brittle and hard. In a word, we know from the latest researches, that all the kinds of hardening water, hitherto invented, are in nothing superior to common water; and that in hardening more depends on the nature of the steel, or rather on the degree of heat, than on the water; although it is true that the workman does right when he adds to the water a thin cake of grease, or pours over it hot oil, through which the steel must necessarily pass before it enters the water, for by these means it is prevented from acquiring cracks and flaws.

The invention of converting bar iron into steel by dipping it into other fused iron, and suffering it to remain there several hours, is commonly

* Fiorillo Geschichte der zeichnenden künste, 1798, 8vo. i. p. 461.

ascribed to Reaumur.* But this

But this process is men

tioned by Agricola,† Imperati,‡ and others, as a thing well known and practised in their time.

Pliny, Daimachus, || and other ancient writers. mention various countries and places which, in their time, produced excellent steel. Among the dearest kinds were the ferrum Indicum and Seriсит. The former appears to be the ferrum candidum, a hundred talents of which were given, as a present, to Alexander in India. Is it not probable that this was that excellent kind of steel still common in that 'country, and known under the name of wootz, some pieces of which were sent from Bombay in the year 1795 to the Royal Society of London? Its silver-coloured appearance

* Art de convertir le fer en acier, p. 245.

† Agricola de re Metallica. Basiliæ 1561, fol. lib. ix. p. 342. Historia natur. Coloniæ 1695, 4to. xv. 27. p. 499. xviii. 18,

p. 581.

§ Page 667: Ex omnibus generibus palma Serico ferro est. Seres hoc cum vestibus suis pellibusque mittunt. Secunda Parthico.

|| Stephanus de urbibus, under the word Aaxedaμwv, p. 413: Λακονικον σιδήριον στομώματαν γαρ το μεν Χαλυβδικον Laconicum ferramentum; acierum enim alia est Chalybdica, alia Sinopica, alia Lydia, alia Laconica.. Sinopica vero et Chalybdica ad fabrilia, Laconica ad limas, et ferrea terebra, et characteres, et ad omnia instrumenta quibus lapides elaborant. Lydia quoque ad limas et machæras et novaculas et scalpra, ut inquit Daimachus in Commentariis poliorceticis. These words have been quoted by Eustathius on the second book of the Iliad.

See the authors already quoted in a note to the article on tin. Clemens Alexandr. in Pædagog. ii. p. 161, according to the edition of Cologne 1688, fol. and to that of Wirzburg, p. 395, says, speaking of luxury: One can cut meat without having Indian iron.

when polished may have, perhaps, given occasion

to the epithet of candidum. paring it is still unknown; be a kind of fused steel.*

The method of prebut it is supposed to This, however, is a

mere conjecture unsupported by any proofs At what time was damasked steel obtained from the Levant?

STAMPING-WORKS.†

In order to separate metallic ores from the barren rock or stones with which they are combined, and to promote the fusion of them, it is necessary that the pieces of rock or stone should be reduced to small fragments, by stamping them, for which the German miners use the term pochen or puchen. For those ores which occur in a sandy form, this is unnecessary; and in regard to rich silver ore, which contains very little or no lead and other metals, this process might be hurtful; for with dry stamping a great deal would fly off in dust, and

* Philos. Transact. 1795, ii. p. 322; and thence copied into Voigt's Magazin für Naturkunde, i. p. 64.

+ I shall refer those desirous of being acquainted with the nature of this labour, to Gatterer's Anleitung den Harz zu bereisen. Gottingen 1785, 8vo. i. p. 101. Figures of the stamping-works may be seen in Calvör's Maschinenwesen des Oberharzes, ii. p. 79; and in Delius' Anleitung zur Bergbaukunst. Wien. 1773, 4to. p 426.

with wet stamping a considerable part would be washed away by the water.

However imperfect the knowledge of the ancients may have been in regard to the fusion of ores, they were acquainted with the benefit of stamping; but the means they employed for that purpose were the most inconvenient and expensive. They reduced the ore to coarse powder, by pounding it in mortars; and then ground it in handmills, like those used for corn, till it acquired such a degree of fineness that it could be easily washed. This is proved by the scanty information which we find in Diodorus Siculus* and Agatharcides,† in regard to the gold mines of the Egyptians; in Hippocrates, respecting the smelting-works of the Greeks, and in Pliny in regard to the metallurgy

* Diodor. iii. 13, p. 182 : Οι δ' ύπερ ετη τριακοντα παρα τούτων λαμβανοντες ὡρισμένον μέτρον του λατομηματος, εν όλμοις λιθίνοις τύπτουσι σιδηροῖς ὑπεροις, αχρις αν ορόβου το μέγεθος κατεργάσωνται. παρά δε τουτων την οραβιτην λιθον άκ γυναίκες και οι πρεσβύτεροι των ανδρων εκδεχονται, και μυλων εξης πλειόνων οντων επι τουτους επιβαλλουσι, και παρασταντες ανα τρις η δυο προς την κωπην αληθούσιν, ες σεμιδάλεως τρόπον το δόθεν μετρον κατεργαζομενοι. Viri trigesimum annum excedentes, certam lapidis eruti mensuram ab illis acceptam, in mortariis saxeis, ferreis pilis contundunt, donec ad ervi magnitudinem sit redacta. Ab his deinceps feminæ virique grandiores lapillos excipiunt, et in molas, quarum longa illic series, congerunt, binique aut terni uni adsistentes paviculæ, eo usque molunt, dum traditam sibi mensuram ad similæ modum contriverint.

+ Photii Biblioth. p. 1342; where the same thing is related nearly in the same words.

Hippocrates de Victus rat. lib. i. edit. Wechel. 1595, fol. sect. 4. p. 13, Χρυσιον εργάζονται, κόπτουσι, πλυνουσι, τήκουσι πυρί. Qui aurum perficiunt, tundunt, lavant, liquant igne.

of the Romans.*

Remains of such mortars and

mills as were used by the ancients, have been found in places where they carried on metallurgic operations; for instance, in Transylvania,† and the Pyrenees. The hand-mills had a resemblance to our mustard-mills; and for washing the mud they employed a sieve,§ but in washing auriferous sand they made use of a raw hide. From the latter, Count von Veltheim has explained, in a very ingenious manner, the fable of the ancients concerning the ants which dug up gold.||

* Plin. xxxiii. 4, sect. 21, p. 617: Quod effossum est, tunditur, lavatur, uritur, molitur in farinam, ac pilis cudunt.

↑ Köleseri de Keres-eer Auraria Romano-Dacica. Cibinii 1717, 8vo. p. 76. Vidi Abrudbanyæ in valle Corna tale mortarium metallieum, supra fundum, aliquot digitis transversalibus perforatum, fundo crassiore et prominente. Of this scarce book, a new edition has been published at Ofen, by J. Seiffert.

Traité de la fonte des mines par le feu du charbon de terre, par M. de Gensane. Paris 1770, 2 vol. 4to. i. p. 14. Speaking of the works of the ancients, the author says: On voit par quelques restes de leurs lavains, qu'ils commençoient par faire rougir leur mineral: ils le concassoient ensuite sous des martaux applatis, après quoi ils le faisoient passer par des moulins à bras tout-à-fait semblable a nos moulins à moutarde, ou aux moulins dont on fait usage pour séparer l'argent de quelques mines par le voie de mercure. J'ai vu un nombre de ces meules aux Pyréneés, et j'en conserve deux très-entieres, du nombre de celles que nous y avons trouvées.

§ Besides the passages already quoted, see Pollux, Onomast. x. sect. 149, p. 1332, and vii. sect. 97, p. 757.

|| Von den goldgrabenden Ameisen und Greiffen der Alten eine Vermuthung von A. F. Grafen von Veltheim. Helmstadt 1799.