Page:A treatise on diamonds and precious stones including their history Natural and commercial.djvu/21

Rh Nos. I. to VI. represent the sizes of brilliants of from one to six carats, cut in exact proportion.

A. An instrument called by diamond cutters "The Compass." It is formed of a piece of plain brass for the base, with a moveable arm in the centre, which in the fig. is set at 45 deg. measuring the inclination of the collet side to the girdle; and of the bizel to the table, at the supplement of the same angle. See p.73.

PLATE II.

FIGURES OF ROUGH DIAMONDS.