Page:A History of Art in Chaldæa & Assyria Vol 2.djvu/292

2ÔÛ A History of Art in Ciiald.ea and Assyria. done he makes use, for the actual engraving, of a kind of lathe, consisting of a small steel wheel which is set in motion by a large cast-iron flywheel turned by the foot. To the little wheel are attached small tools of soft iron, some ending in a rounded button, others in a cutting edçe. The craftsman holds the staff with the stone in his left hand ; he brings it into contact with the instru- ment in the lathe, while, from time to time, he drops a mixture of olive oil and diamond dust upon it with his right hand ; with the help of this powder the instrument grinds out all the required hollows one after the other." * The first engravers who attacked precious stones had no diamond dust. They supplied its place with emery powder, which was to be found in unlimited quantities in the islands of the Archipelago, whence it was imported by the Phoenicians at w Fig. 138. — Engraved shell. British Museum. a very early date. Moreover there was nothing to prevent them crushing the precious stones belonging to the class called corundum, such as sapphires, rubies, amethysts, emeralds, and the oriental topaz. No doubt the lathe or wheel was a comparatively late invention. M. Soldi thinks it hardly came into use in Meso- potamia till about the eighth century b.c. Before that the continuous rotary movement that was so necessary for the satisfactory con- duct of the operation was obtained by other means. According to M. Soldi they must have employed for many centuries a hand- drill turned by a bow, like that of a modern centre-bit or wimble. 2 1 E. Soldi, Les Cylindres babyloniens {Revue archéologique, vol. xxviii. p. 147). 2 Ibid. p. 149.