The anti-monopolist. [volume] (Saint Paul, Minn.) 1874-1878, 1877-10-11

advantages due to the bath, which is
composed of oil or other greasy
material heated to a temperature
varying between 800. and 572o Fab,
according to the quality OF glass to be
tempered. When the red hot article
is plunged in, the oil easily takes fire.
This can, of course, be avoided by
proper precautiOn, but it is obviously
a cause of danger. There are, besides
the disagreeable odor arising from the
bath, the large expenditure OF oil,
which decompOses on contact with
the hot glass, and finally the fact that
each special composition of glass
requires different temperature OF
the bath, and it is very difficult to
maintain exactly this temperature
during the operation. 1t will thus be
clear that in the bath is the weak
point of M. de la Bastie's process.
Herr T. Siemens, who has devoted
considerable attention to the Bastie
plan with the hope Of overcoming
some of it's practical difficulties, ap-
pears to have become convinced that
the invention is inapplicable to the
fabrication of certain forms of glass,
among which are included window
panes. To these last any hardening
process probably finds it's most
important application. After some
experiment Herr Siemens reached
the conclusion that solid bodies, or
rather molds, could be substituted for
the cooling bath. His first attempts.
made with the object OF hardening
small squares of glass between plates
of baked earth, showed clearly that
the idea was practicable. This was
eighteen months ago, and during the
subsequent interval up to the present
Herr Siemens has achieved constantly
improving and successful results.
The Deutsche IaduStrie Zeatung,
whence we take our facts, states that
the method Of fabrication of the
compressed glass is not merely glass
hardening process. 1t constitutes at
the same time veritable method OF
glass making. Tempering, blowing land
molding are all accomplished in one
and the same operation.
1t will be perceived, however, that
, all objects in glass cannot be made by
this process, and that it's application
; is restricted to such as can be pressed
, between two simple forms. To this
category, however. belong window
panes, to which at present Herr Sic
mems proposes to restrict his manu-
, facture. In brief, the Bastie and
Siemens methods may justly be
! regarded as each having its peculiar
; sphere. Bastie's plan is especially
! suited for cylinders, hollow glass, and
other articles of complicated form.
. while Siemens' system, as already
! stated, is best applied to simple figures
: The resistance of the SiemenS glass
= to shock is stated to be ten times
> that Of common glass, but it's cost is
Q about SO per cent higher, except in
= case Of curved window panes, wheI
q it is the cheaper. 1t is said to be
+ harder than other tempered glass
: and to present a fibrous instead of ;
f crystalline fracture. 1t may bt
polished or pierced without the
!. rupture which occurs in the. Bastit
9 glass. Herr Siemens is engaged upor
q still further improvements, which j
I Is believed will tend to decrease tht
: cost.
= At the Lyons Industrial Society
Q recently, M. Leger proposed temperins
bottles and similar glass objects by
v steam. The tensile resistance of ths
i glass thus prepared, he states, is abou
: equal to that of cast iron. No detail:
: of the process are given.