IMPROVEMENTS IN THE PROCESS FOR ORNAMENTING GLASS-WARE, IN THE MOLDS THEREFOR, AND IN THE MEANS FOR ETCHING THEM
Year: 1879

page_text: LETTERS PATENT to Alfred Julius Boult, of the Firm of Wm. P. Thompson & Co.,
323, High Holborn, in the County of Middlesex, Patent Agents, for the Inven-
tion of "IMPROVEMENTS IN THE PROCESS FOR ORNAMENTING GLASS-WARE, IN
THE MOLDS THEREFOR, AND IN THE MEANS FOR ETCHING THEM." A communi-
cation from abroad by Henry Feurhake and Washington Beck, of Pittsburgh,
in the County of. Alleghany, and State of Pennsylvania, United States of
North America.
Sealed the 14th November 1879, and dated the 15th September 1879.
COMPLETE SPECIFICATION filed by the said Alfred Julius Boult at the Office
of the Commissioners of Patents on the 15th September 1879.
$6
ALFRED JULIUS BOULT, of the Firm of Wm. P. Thompson & Co., 323, High
Holborn, in the County of Middlesex, Patent Agents. IMPROVEMENTS IN THE
PROCESS FOR ORNAMENTING GLASS-WARE, IN THE MOLDS THEREFOR, AND IN THE
MEANS FOR ETCHING THEM." A communication from abroad by Henry Feurhake
and Washington Beck, of Pittsburgh, in the County of Alleghany, and State of
Pennsylvania, United States of North America.
DESCRIPTION.
Our Invention relates, first, to that class of glass-ware, whether blown or pressed,
wherein the ornamentation is produced in the mold, and consists in an article of
glass-ware ornamented either over its entire surface or by a raised or depressed design
or figure formed thereon, the distinguishing characteristic of which is a fine granular
surface which partially obscures and partially refracts the light, whereby a new and
peculiar effect is produced. In the ornamentation of glass-ware of that class,
wherein portions are left clear and other portions obscured, several general methods
have been adopted, as, for instance, a stop-out varnish or acid resistant has been
applied to portions of the article, and the unprotected portions have been etched by
hydrofluoric acid, either in a gaseous or liquid state, or the design has been formed
on the glass in raised or sunken figures, or by means of fine lines, and the raised por-
tions of the glass subsequently obscured either by the brush or the wheel; or in some
instances, when the article had an uniformly plain surface, limited portions thereof
have been subjected to the wheel for the purpose of ornamentation. These several
inethods all produce good and useful results, but to a greater or less extent demand
the employment of skilled labor, necessitate the treatment of the article after it
1

page_text: leaves the mold, and multiply the labor and expense of manufacture. The object of
the first part of our Invention is to produce the ornamentation of the article by the
mold, and reduce the labor and cost of manufacture.
The second part of our Invention relates to the method or manner of producing
the molds, whereby the surface of the mold, or portions thereof, will be left in a
condition adapted to obscure the surface of the glass, or portions thereof, and con-
sists in etching the mould, or portions thereof, by a suitable acid, or in engraving the
mold by a sand blast or like means, which will leave the surface of the metal
uniformly roughened with minute indentations, or granular, and adapted to minutely
indent or roughen the glass formed in the mold. Heretofore, in the production of a
glass-mold, the casting, therefore, have been properly dressed and polished upon its
interior, the design or pattern to be produced in or on the glass have been cut or
engraved on the interior of the mold by tools and hand labor in the usual manner
of engraving metals. This procedure involved the employment of skilled mechanics,
and the interior surface of the mold has been left in a smooth and finished condition,
so that the glass formed therein would have an uniformly polished surface impressed
to it by the mold. So far as we are aware, no known tools used, or method heretofore
practised by glass-mold makers, would enable them to give the face of the mold the
uniform fine granular finish required; certainly not except at the cost of much time
and labor. The object, therefore, of the second part of our Invention is to simplify,
cheapen, and expedite the production of molds for the manufacture of ornamented
glass-ware of the class specified.
The third part of our Invention relates to the manner of applying the protective
coating to those portions of the mold which are to be protected against the action
of the acids used in etching the designs upon the mold; and the fourth part of our
Invention relates to the acid or compound acid preferably employed, all as herein-
after set forth.
If the object in view is to produce an article of glass ware the entire surface of
which is to present the granular or ornamental appearance, the bottom of the mold
is closed, and if the mold is a partible mold the joints are protected by any of the
well known acid resisting substances used as a stop out in etching metals, after
which the mold is filled with an acid, or equivalent substance, which will attack the
metal. The acid may be drawn off from time to time, and the interior surface of
the mold examined. When the surface of the mold has been sufficiently etched or
roughened by the acid the mold can be washed, the stop out removed from the
joints and bottom, and it will be ready for use. But in general it will be found
most desirable to ornament the glass-ware by either raised or depressed designs, in
which case certain portions of the mold will be acted upon by the acid. If the
figure or design of the article of glass-ware is to have a raised granular surface, then
all of the mold except the design or figure is protected by the stop-out; and, on the
contrary, if the design or figure on the glass-ware is to be depressed and clear, and
the surrounding surface is to be raised and granular, then the design or figure alone
is protected by the stop-out, and the remainder of the interior surface of the mold
is exposed to the action of the acid. Any well known way of applying the stop-out
and the design of the surface of the mold may be adopted, as, for instance, the design
or figure may be traced on tracing paper, and then transferred to the mold by the
use of duplicating paper, or the design may be drawn directly on the surface of the
mold. Those portions of the mold which are to be protected against the action of the
acid or acids may then be covered or painted over with asphaltum or varnish; or in
some instances the whole interior surface of the mold may be first uniformly coated
with asphaltum, varnish, or equivalent stop out, and then the varnish removed by
suitable instruments, to expose such portions of the mold as are to be eaten away
by the acid to form the figure or design.
The method preferred by us, however, especially where the design or figure is very
fine or intricate, is as follows:-
First. The design or figure is cut in intaglio on box wood, steel, copper, or litho-
graphic stone. The stone or its equivalent is then inked without dampening it, and

page_text: By this
the design is painted upon dry "French folio," or onion skin paper; the paper
having the design upon it is then applied to the surface of the mold and carefully
pressed, to cause the ink to adhere to the surface of the mold; the paper is slightly
dampened, when it can be readily removed without detaching the ink.
means the design or figure will be transferred to the mold surface. The ink so
transferred is then dusted over with a mixture of one (1) part of rosin and one (1)
part of gum asphaltum, which should be gently rubbed in with the fingers, so as to
fill the ink and increase its density. The mold should then be slightly warmed,
care being taken not to heat it to such a degree as to melt the rosin, and again
dusted with the composition of rosin and asphaltum, the warming of the mold and
the dusting of the design being repeated until a solid body for the design is obtained.
The joints and such other portions of the mold (besides the design) as are to be
protected against the action of the acids are then coated with asphaltum varnish,
the bottom of the mold is then closed and rendered watertight and acid proof
by a coating of bees-wax or asphaltum. The portions of the mold surrounding
the design will, of course, be left unprotected for the action of the acid. The
mold having been prepared as specified, the acid is introduced into the mold
and allowed to remain 15 or 20 minutes, and is then removed and the action of the
acid noted; if the surface of the mold is not sufficiently etched or cut deep enough
the acid is replaced and allowed to remain a short time, and again removed. This
application of the acid is repeated until the metal of the mold is cut to such a depth
that it will properly imprint the figure on the glass-ware. The varnish and bottom
plug are then removed, the mold is thoroughly washed to remove all traces of the
acid, and is then ready for use. The transfer ink used for printing upon the French
folio paper is preferably an ink composed of beef tallow one (1) part, bees-wax one
(1) part, rosin two (2) parts, asphaltum one (1) part, and lamp black one half ('/2
part), all of which are boiled together and intimately mixed. The French folio or
onion skin paper may be made by coating paper with the following composition:
starch one (1) pound, glycerine one (1) ounce; boil the starch, then add the glycerine
and stir the two together while boiling. The acid composition preferred by us for
etching the metal is composed as follows:-Proligneous acid five (5) parts, alcohol one
(1) part, nitric acid one (1) part. The proligneous acid and alcohol should first be
mixed together, after which the nitric acid is added.
Throughout the body of the description we have spoken of acid as the agent for
etching the mold for the reason that the same is sufficiently cheap and very manage-
able, but in lieu thereof any agent adapted to attack the metal may be employed, or
the well known sand blast may be used after the mold has been properly prepared
with the design as before specified. It will be readily understood that if the design
or figure is cut in the stone or its equivalent in intaglio it will be the same on the
mold, and the figure will be in bas relief on the glass-ware; or, in other words, the
design having been formed in that portion of the mold which was exposed to the
action of the acid will be rough or granular and raised, while the body of the article,
having been formed in that portion of the mold which was protected from the acid,
will be clear and polished. It is, of course, evident that in molds for pressing glass
the plunger may be prepared in like manner as the mold, and it is here proper to
say that it will be observed that in pressing glass that the design imprinted by the
plunger upon the article will in all cases be much sharper, clearer, and more accurate
than that imparted by the mold. This is due to the fact that when the glass is cut
into the mold it is slightly chilled where it first comes in contact with the mold, and
loses some of its plasticity at that place before the forming pressure is applied, for
which reason, wherever practicable, we prefer, in practising our Invention, to reverse
the usual practice, that is, to form the design upon the plunger or its equivalent
(pressing upside down), as the more plastic the glass is at the time the design is
printed thereon the better will be the results.
In some instances it may be desirable to form the outline or other portions of the
figure coarsely granular, and the body (or other certain portions) of finer granular
character, in which case the coarser granular condition of the mold may be produced

page_text: by the action of one acid, for instance, a compound acid hereinbefore specified,
and the finer granular condition produced by another acid, as, for instance, a com-
pound acid composed of nitric and fluoric acids, in which case we prefer to form
the finer granular surface first, and then protect the same by a varnish or stop out
during the action of the acid which forms the coarser granulation. Any suitable
metal may be used for forming the molds, but we prefer homogeneous steel,
cast steel, chilled cast iron, phosphor bronze, carbon bronze, or brass.
In addition to the obtaining of a new and highly ornamental finish for glass ware,
another great advantage of our Invention is the fact that drop molds can be readily
and cheaply cut, so as to produce ornamental ware, which it has been hitherto
impossible to do, except at great expense.
Having now described our Invention, and the manner in which the same may be
carried into practical effect, what we claim as new, and desire to secure by Letters
Patent, is,
1st. An article of glass ware ornamented in whole or in part by a granular sur-
face, which partially obscures and partially refracts the light substantially as and
for the purpose specified.
2d. A mold for the manufacture of glass-ware, the forming face or faces of which,
in whole or in part, has the fine granular or unfinished condition such as is produced
by the action upon metals of acids or a sand blast substantially as specified.
3d. As an improvement in the manufacture of glass-molds for producing orna-
mented glass-ware; first printing the design upon paper; secondly, transferring the
design to the surface of the mold to be etched; thirdly, increasing the density of the
transferred ink by the application of an acid resisting powder; fourthly, protecting
the joints and like portions of the mold by a suitable stop out or acid resisting
substance, and finally applying an acid to the unprotected surface of the mold, in
order to etch the same as specified.
4th. A composition acid for etching molds, consisting of pyroligneous acid, alcohol
and nitric acid, substantially as specified.
In witness whereof, I, the said Alfred Julius Boult, have hereunto set my hand
and seal, this Fifteenth day of September, in the year of our Lord One
thousand eight hundred and seventy nine.
PATYT M
ALFRED J. BOULI. (L.S.)