Page:Popular Science Monthly Volume 8.djvu/222

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210
THE POPULAR SCIENCE MONTHLY.

of capital is said to be invested in this adventure, and employment is given to forty or more workmen, all Israelites, with the aid of steam-power. The establishment already boasts of having cut a fine crystal from South Africa, weighing eighty carats.

Fig. 9.—Form of the Rose-Cut. Fig. 10.—Form of the Table-Cut.

The process of cutting the diamond is divided by the Jews into several distinct branches, and workmen are educated to perform one part but not another. Thus the cleaving, the cutting, and the polishing, have special operators, who become expert in performing well the parts assigned to them, without attempting the others. This course has undoubtedly produced skillful workmen, but we see no reason why all the parts may not be perfectly acquired by an intelligent mechanic. The art of cleavage, however, requires tact, and ought to include some knowledge of mineralogy. For the particulars of the art of diamond-cutting, we will refer our readers to the interesting works of Jeffries, Mawe, and Barbot; still we briefly mention here some of the forms adopted for the diamond, and how they are produced.

Fig. 11.—The Star of the South. Weight, 124+14 carats. Fig. 12.—The Great Mogul. Weight, 279 9/16 carats.

The table and the rose patterns were the first regular forms adopted by the lapidaries. The first was simply the top of the stone ground flat, with a corresponding flat bottom of less area, with its four upper and lower sides parallel to each other. As the light passed through the stone without much refraction, the beauty of the mineral was not developed by this pattern. It has been stated that the rose-shape was