A NEW AND IMPROVED METHOD OR PROCESS OF ALLOYING METALS BY CEMENTA- TION, PARTICULARLY APPLICABLE TO THE PRESERVATION OF COPPER, WROUGHT OR CAST IRON, AND OTHER METALS, AND THEREBY OPERATING A CHANGE IN THE APPEARANCE OF THEIR SURFACE, AND GIVING THEM MORE BRILLIANCY
Year: 1838

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, MILES
BERRY, of the Office for Patents, Chancery Lane, in the County of Middlesex,
Patent Agent and Mechanical Draftsman, send greeting.
WHEREAS Her present most Excellent Majesty Queen Victoria, by Her
Royal Letters Patent under the Great Seal of Great Britain, bearing date at
Westminster, the Third day of May, One thousand eight hundred and thirty-
eight, in the first year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said Miles Berry, Her especial licence, full
power, sole privilege and anthority, that I, the said Miles Berry, my executors,
administrators, and assigns, and such others as I, the said Miles Berry,
my executors, adññors, or assigns, should at any time agree with, and no
others, from time to time and at all times during the term of years therein
expressed, should and lawfully might make, use, exercise, and vend, within
England, Wales, and the Town of Berwick-upon-Tweed, the Invention of
"A NEW AND IMPROVED METHOD OR PROCESS OF ALLOYING METALS BY CEMENTA-
TION, PARTICULARLY APPLICABLE TO THE PRESERVATION OF COPPER, WROUGHT OR
CAST IRON, AND OTHER METALS, AND THEREBY OPERATING A CHANGE IN THE
APPEARANCE OF THEIR SURFACE, AND GIVING THEM MORE BRILLIANCY," communi-
cated to me by a certain Foreigner residing abroad; in which said Letters
Patent is contained a proviso, I, the said Miles Berry, shall cause a particular
description of the nature of the said Invention, and in what manner the
same is to be performed, to be inrolled in Her said Majesty's High Court
of Chancery within six calendar months next and immediately after the

page_text: date of the said in part recited Letters Patent, as in and by the same,
reference being thereunto had, will more fully and at large appear.
NOW KNOW YE, that in compliance with the said proviso, I, the said
Miles Berry, do hereby declare that the nature of the, said new and improved
method or process of alloying metals by cementation, and the manner in
which it is to be performed, as the same have been disclosed to me, are
fully set forth and described in the following Specification thereof (that is to
say) :-
=
The alloying or changing of metals by cementation is a process well
known in metallurgy, but I am not aware that any metal has ever been before
so changed or protected by this process that it would resist the action of air,
or humidity, or of certain acids, whereas copper and iron, both wrought and
cast, and other oxidizable metals, when they have been subjected to the said
process, according as the same is modified to suit each particular description of
metal, resist all these sources of oxidation.
And first, as regards copper, after it has been cleansed it is placed in
a furnace covered with a mixture of charcoal and powder of zinc, and
the temperature then raised to cherry red, which degree of temperature
is kept up for a longer or shorter period, according to the bulk of the
article or to the desired thickness of the coating and colour to be given
to the article. The operation is one of great nicety, for which I am
informed no definite rules can be laid down, but that experience will enable
any competent workman to perform it with sufficient exactness. It will be
found that in every case there is a point at which the copper, when taken out
of the furnace, is perfectly .inoxidizable, whereas, if the operation lasts too
long, the produce is nothing but common brass very readily oxidized.
•
Second, with respect to iron. For the preparation of this metal, two parts of
zinc and three parts of copper are melted together in a crucible or any other
suitable vessel, and into this mixture or alloy, the piece of iron, after being.
well cleaned, is plunged. If bulky, the article is heated before-it is dipped
into the crucible, and the better to exclude the atmosphere, the, zinc and
copper bath is covered with a layer of sal-ammoniac, or melted rosin, or
borate of soda, or other suitable substance, preferring, however, the sal-
ammoniac, which is found in practice to answer better than any other interposed
medium. The process thus described is occasionally reversed (that is to say):
a boiling solution of the sal-ammoniac or borate of soda is prepared, and the
iron dipped therein, before immersing it.in the zinc and copper bath, but I am
not advised to recommend this process as preferable to the other. The article,
being prepared by one or other of these methods, is put into a layer of

page_text: charcoal powder in a furnace, and exposed to a strong red heat until the
fumes of zinc begin to abate. It is not well to until the vapours indicate
no longer any zinc. The quicker the operation, the better is the result. The
piece of iron must be taken out of the furnace, still covered with charcoal, and
in that state plunged into water or allowed to cool slowly.
A third modification of the process is as follows:-An alloy is made of
zinc and copper in the proportions aforesaid, namely, two parts, of zinc to three
parts of copper, and when cooled, is to be put into a mortar with a quantity
of borax and pulverized. The iron, well scoured and cleaned, is then smeared
over with fat, oil, grease, or other unctious substance, or merely wetted
with water, and when thus prepared, it is dipped into the zinc and copper
powder, whence it is taken to be plunged into the charcoal powder, and
subjected to a strong red heat, as herein-before, directed, until the fumes
of zinc begin to abate.
A fourth variety of the process is to dip the iron into a solution of
sulphate of copper (after being perfectly cleaned) and to suffer it to
remain there for a time. As soon as the iron is covered with
a sufficient
covering of precipitated copper, it is taken out, plastered with potter's earth
mixed with water, and then covered with a layer of pulverized zinc and
borate of soda, or other substitute for the same; or the pulverized zinc, borate
of soda, or other substitute may be made into a paste with the clay and water,
and the article smeared over with the said paste. The iron is then placed in
the furnace covered with charcoal powder, and heated to white heat for some
minutes. The rest of the process is the same as before described. The metals
thus rendered inoxidizable are either of a gold or silver hue, according to the
length of the operation or the quantity of zinc that combines with the copper.
The brightness of the gold color alloy may be enhanced by rubbing the
article with vegetable charcoal, or the soot from a wood fire, and nitric acid.
It is proper to add, that instead of pulverized zinc, I have been informed
pulverized calamine may be used.
And having now fully specified all that has been disclosed, or is known to
me of the said process, I declare that what I claim as new is the process of
alloying by cementation herein-before described in its several varieties, by which
copper, iron, and other oxidizable metals are preserved from oxidation, their
surfaces are changed in appearance, and also rendered more brilliant.
And such my Invention being, to the best of my knowledge and belief,
entirely new, and never before used within that part of Her said Majesty's
United Kingdom of Great Britain and Ireland called England, Her said

page_text: Majesty's Dominion of Wales, and Town of Berwick-upon-Tweed, I do
hereby declare this to be my Specification of the same, and that I do verily
believe that this my said Specification doth comply in all respects fully, and
without reserve or disguise, with the proviso in the said herein-before in
part recited Letters Patent contained; wherefore I hereby claim to maintain
exclusive right and privilege to my said Invention.
In witness whereof, I, the said Miles Berry, have hereunto set my
hand and seal, this Thirtieth day of October, in the year of our Lord
One thousand eight hundred and thirty-eight.
MILES (L.B.) BERRY.
AND BE IT REMEMBERED, that on the Thirtieth day of October, in
the second year of the reign of Her Majesty Queen Victoria, the said
Miles Berry came before our said Lady the Queen in Her Chancery, and
acknowledged the Instrument aforesaid, and all and every thing therein contained
and specified, in form above written. And also the Instrument aforesaid was
stamped according to the tenor of the Statute made in the fifty-fifth year of
the reign of His late Majesty King George the Third.