184. Boubée, A. Jan. 21.
Blowing; materials; moulding; obtaining metal; pressing; stained glass. A mould for forming articles
such as lamp globes &c., is of approximately spherical form, and is
divided into three or more segments A, Fig. 1, jointed at B and held
together by handles. The mould is placed upon an iron plate, and a bulb
of glass is introduced upon the end of a blowing tube and blown in the
mould. The glass may protrude from holes G in the sides of the mould,
so as to form convex surfaces D for use as watch glasses, signal
lights, lanterns, &c. Buttons, studs, knobs for
doors, walking-sticks, umbrellas, &c., in imitation of agates,
marbles, &c., are made from a fused mixture of powdered stones,
saltpetre, and "salt of potash," with the addition of small quantities
of malachite or the like, according to the colour desired. A bulb of
the fused composition is placed between the dies F, which are secured
to the spring jaws R of a vice or pair of pincers by the set-screws G.
The jaws are then forced together by a nut N, so that the composition
takes the form of the dies, the adjustable rod I forming a cavity for
the insertion of a screw &c. in the finished knob. The same
composition may be moulded in a hinged mould closed by hand pressure.
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