It seems to be a peculiarity in the history of the diamond that from time to time operations which have been known from time immemorial are re-invented and claimed to be new. For instance, cleaving, which is said to have been known to the Indians, was discovered again by W. H. Wollaston. It is obvious, too, that cleaving was already known to A. B. de Boodt in 1604. The same applies to the sawing of gems by a thin rotating disk, which seems to be as old as the engraver's treadle lathe (earliest reference about 1520) ; but this art does not seem to have been applied to diamonds, as the first reference to diamond sawing with a thin rotating blade is that in 1874. All previous references seem to be to the sawing of diamonds with a thin wire moistened with a paste of diamond dust and oil, and otherwise designated as the Chinese method. Other gemstones, were always sawn with thin disks on lapidaries' benches with vertical spindle. Similar remarks may be applied to bruting and drilling, but only polishing seems to have always been recognized as the main operation.