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THE ART OF THE CUTTER
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Shaping is another term, better than most of the others— but we shall stick to American usage and say cutting.
What
happens is this: In the old days—and still in Europe, it is generally
understood—two stones of about the same size were selected and held
firmly imbedded with a hard cement in the pit at the end of two wooden
holders, so that the parts to be shaped were exposed. The holders were
held one in each hand and the stones rubbed hard, one against the
other, until the surfaces of the requisite size were developed on each.
During the process the stones were held over a small box which caught
the precious powder for use in sawing or polishing. A sieve at the
bottom of the box allowed the powder to fall through into a tray placed
underneath but retained anything larger.
The
new method in America depends as much upon machinery as upon the skill
of the workman. The sieve-and-box idea for retaining the dust is the
same. Otherwise, a lathelike machine with a horizontal shaft, the head
of which has an eccentric adjustment, holds a stone, attached by means
of shellac cement to the hollow at the head of the dop. (Dop is an old
Dutch word meaning shell and refers to the shape of the brass cup
originally used to carry the solder holding the diamond during
polishing.) The base of the dop, which measures about an inch and a
half in length and three-quarters of an inch in diameter, is screwed
onto the adjustable head of the shaft.
Then
if the workman has orders to cut a brilliant with circular girdle the
stone is truly centered; if the form is to be a marquise, the stone is
placed the appropriate distance from the center. Another stone is
mounted sideways in another dop, screwed to the head of a steel rod,
and then the "round" places the rod firmly under his arm and rests it
near the dop against a stout vertical pin fixed to the
(89)
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