40 



LAPIDARY 



cimens of their skill. The Greeks were passionate lovers of rings and engraved 

 stones ; and the most parsimonious among the higher classes of the Cyrenians are said 

 to have worn rings of the value of ten minse (about 30/. of our money). By far the 

 greater part of the antique gems that have reached modern times may be considered 

 as so many models for forming the taste of the student of the fine arts, and for in- 

 spiring his mind with correct ideas of what is truly beautiful. With the cutting of 

 the diamond, however, the ancients were unacquainted, and hence they wore it in its 

 natural state. Even in the middle ages, this art was still unknown ; for the four large 

 diamonds which enrich the clasp of the imperial mantle of Charlemagne, as now pre- 

 served in Paris, are uncut, octahedral crystals. But the art of working diamonds 

 was probably known in Hindostan and China in very remote periods. After Louis de 

 Berghen's discovery, in 1476, of polishing two diamonds by their mutual attrition, all 

 the finest diamonds were sent to Holland to be cut and polished by the Dutch artists, 

 who long retained a superiority, now no longer admitted by the lapidaries of London 

 and Paris. See DIAMOND. 



The operation of gem-cutting is abridged by two methods: 1, by cleavage; 2, 

 by cutting off slices with a fine wire, coated with diamond-powder, and fixed in 

 the stock of a hand-saw. Diamond is the only precious stone which is cut and 

 polished with diamond-powder, soaked with olive oil upon a mill plate of very soft 

 steel. 



Oriental rubies, sapphires, and topazes, are cut with diamond-powder soaked with 

 olive oil, on a copper wheel. The facets thus formed are afterwards polished on 

 another copper wheel, with tripoli, tempered with water. 



Emeralds, hyacinths, amethysts, garnets, agates, and other softer stones, are cut at a 

 lead wheel, with emery and water ; and are polished on a tin wheel with tripoli and 

 water, or, still better, on a zinc wheel, with putty of tin and water. 



The more tender precious stones, and even the pastes, are cut on a mill-wheel of 

 hard wood, with emery and water ; and are polished with tripoli and water on another 

 wheel of hard wood. 



Since the lapidary employs always the same tools, whatever be the stone which he 

 cuts or polishes, and since the wheel discs alone vary, as also the substance he uses 

 with them, we shall describe, first of all, his apparatus, and then the manipulations for 

 diamond-cutting, which are applicable to every species of stone. 



The lapidary's mill, or wheel, is shown in perspective in fig. 1316. It consists of 

 a strong frame made of oak carpentry, with tenon and mortised joints, bound together 

 with strong bolts and screw nuts. Its form is a parallelepiped, of from 8 to 9 feet 

 long, by from 6 to 7 feet high ; and about 2 feet broad. These dimensions are large 

 enough to contain two cutting wheels alongside of each other, as represented in the 

 figure. 



1317 1318 



1316 



X 



3 



Besides the two sole bars B B, we perceive in the breadth, 5 cross bars, c, D, E, F, o. 

 The two extreme bars c and G, are a part of the frame-work, and serve to bind it. 

 The two cross-bars D and F, carry each in the middle of their length, a piece of wood 

 as thick as themselves, but only 4 inches long (see fig. 1316), joined solidly by 

 mortises and tenons with that cross-bar as well as with the one placed opposite on the 



