This simple process was, no doubt, employed anterior to engraving
by the lathe; to this it probably gave way, as the accurate artistic
effects of the lathe far surpass the crude work of steel or diamond
etching. Etching by fluoric acid has been introduced, but its bite is
not sufficiently rough, and is not found effective for general purposes.
Pleasing effects are produced by engraving through an outer casing of
coloured Glass, usually afterwards decorated with gold, and painted
in arabesques, or other patterns. This work is chiefly the produce
of Bohemia, Bavaria, and France; it has recently been executed at the
Falcon Glass Works with success, in engraved classical designs.
Stoppering is usually done within Flint
Glass premises. The lathe is similar to that employed by Glass engravers,
being what is termed a mandril tool. The mouths of the bottles are opened
by a steel projecting cone, or mandril, to the required size to suit the
stopper; and emery powder and water being applied, the rotating friction
soon effects its object. The stopper must be fixed in a wooden chuck,
and rotated by the lathe, to be first reduced to the dimensions of the
mouth of the bottle, by emery and water; and finally introduced into
it, carefully grinding the one into the other, reducing the speed,
and supplying by degrees finer and finer emery (and water), until the
stoppering by the lathe is completed; a few turns of the stopper with
the hand follow to finish.