Afterwards Nuremburg produced many expert masters in the art, who, from the improvement in the tools, and also from discovering more economical modes of using them, were enabled to execute the orders of the public at a more moderate rate than had been previously charged for some articles. Those latter masters likewise brought this art to a much greater degree of perfection. Notwithstanding Zahn was of the same country, and must have been apprised of the facts previously stated, yet he mentions it as a very recent invention at Nuremberg, at the time he published his “Oculus Artificial.” He also furnishes a plate, giving at the same time a description of the various instruments employed. However, that this invention is not purely _novel_, may be perceived from those facts we have already submitted. It should be stated that before this latter re-introduction, artists used, with a diamond, to cut figures upon glass in almost every form, as far as the representation by lines went. The history of diamonds has been presented to the public by Mr. Mawe, in his observations on the diamond districts of Brazil. It appears to be yet undetermined whether the ancients used that stone for the purpose of cutting others; upon this point Pliny appears to be satisfied that they did. Solinus and Isidore both express themselves in a manner the reverse. But although this may leave us in some doubt, it appears pretty clear that they did not attempt to cut that valuable production with its own dust, or to give it different faces, or render it more brilliant by the same means. If this point was settled, there could be no great difficulty in affirming or negativing the fact of their engraving upon that stone. Thus doubts appear to increase on this head, for Mariette denies that they did; Natter appears uncertain; and Klotz asserts with confidence it was certain. His authority, to be sure, has been considered not to be of much weight. The proper question, however, appears to be, whether the Greeks and Romans used diamonds for cutting and engraving other stones or glass. Natter, in his work already noticed, thinks they were employed on some antique engravings. His authority is deserving respect. But if they were employed on other stones, the authority which at present directs us, confidently alleges they did not employ them in cutting glass; but he points out the mode in which that article was wont to be divided, in the following terms: “They used for that purpose emery, sharp-pointed instruments of the hardest steel, and a red-hot iron, by which they directed the rents at their pleasure.” The first mention which appears to occur of the use of the diamond for this purpose, is recorded of Francis I. of France, who, fond of the arts, sciences, and new inventions, wrote a couple of lines with a diamond, on a pane of glass in the Castle of Chambord, to let Anne de Pisseleu, Duchess of Estampes, know that he was jealous.