92 NATURAL HISTORY OF PRECIOUS STONES, &c.
plane,
the opposite extremity being likewise reduced to a plane, but of much
smaller area ; the sides were brought to a right angle with each other
; this proportion being observed, that the width of two sides added
together should equal that of the upper plane surface, which gave the
pattern its name of the Table. But if the stone were a Lasque (a
flat, shallow parallelogram), then the lower portion was dispensed
with, and the Table consisted of nothing more than the top and the
upper sloping sides, nothing being left below the setting edge, or girdle. These proportions are taken from De Boot, who, writing some forty years after Kentmann, observes that although, the Point was the most frequently seen (as the view of any collection of Cinque-cento jewels will confirm) j'et the Table was
considered of much higher value. This latter pattern was indeed no
novelty, it had long been a favourite with the mediasval lapidaries for
cutting all the softer stones. Often by slicing off the corners of the
square they produced the octagon, a form then highly in vogue on
account of its Pythagorean mystic virtue : and antique gems thus
reshaped frequently occur in the signets of the times. The pieces of
rock crystal mounted in the huge Papal credential rings of the
same period are cut as regular tables. The harder stones, like the
Sapphire, were, as in antiquity, polished with more or less regularity
into a double-convex form, now termed cut en cabochon (from cobo, a head), known to the English trade by the homely but expressive name of tallow-drop.
The seventeenth century introduced several novel patterns into the atelier of
the diamond-cutter. De Laet, writing in 1647, thus notices the great
advance the art had made in his own times. " The industry of these
diamond-workers has of late years made very great progress, so that
they no longer require the aid of such
