then reheating at the furnace, and simultaneously expanding the
reheated ball of Glass by blowing; thus separating the crystals from
each other, and leaving open fissures between, which is done preparatory
to forming vases or ornaments. Although frosted Glass appears covered
with fractures, it is perfectly sonorous.
WELDED COLOURED GLASS.
Welding coloured Glass to white or
lighter-tinted Glass, for windows, skylights, &c., has been patented
by the author. It is effected with detached pieces of dark-coloured
Glass prepared by cutting, pinching, or moulding; these are placed in
the interstices of cast brass, or iron moulds, previously chased by the
die-sinker; and the whole are gradually heated to nearly a red heat.
Hot white, or light-tinted Glass, is then cast upon the mould, about the
consistency of honey; the entire mould is covered with it, and rubbed
with wood, till cold enough for annealing; when it will be found firmly
welded to the detached coloured pieces, and will deliver from the mould as
one entire mass. Should one uniform tint only be required, the detached
coloured pieces are dispensed with; and the rolling or pressing is the
same with one colour as with the above various tints; the light and shade
being produced, where one colour only is used, by the unequal substances
of the tinted Glass having a tendency, in the thickest portions, to
exhibit complementary colour.*
* Rosettes for windows may be pressed
at a very reduced price by this process. Mr. Eastlake, Secretary to the
House of Lords' Commission, allowed several specimens made at the Falcon
Glass Works to be exhibited in St. Jame's-street, at the first public
display of works of art in connexion with the Commission.