pinched a part of it, by means of a small instrument, to form
the neck of the bottle.
He next inserted the end of the tube into a small brass mould lying on
the ground, shut up the two parts of which the mould consisted, and blew
through the tube.
This double operation produces a curious effect, for while the air from
the lungs, passing through the tube, makes the mass of Glass hollow, the
mould at the same time imparts to it the external form required. The mould
being opened, the Glass—now in the form of a bottle—was
The mould A
, as sketched,
is termed an open and shut mould, and is generally constructed in two
exact halves, (connected with a bottom hinge,) which in a round bottle
shows two seams or lines, caused by the two sides of the mould not
shutting quite closely.
The seam is not unsightly in the square form, as the joint takes place at
two of the corners, B
. Many manufacturers prefer moulds
for round bottles, of one piece for the body, C
, and two
pieces for the neck, (D D
,) by which the seam down the
body is avoided; although two slight seams are observable in the neck.
is an expanded ball of