IMPROVE. MENTS IN COATING IRON AND STEEL WITH GOLD, SILVER, AND COPPER, AND IN APPARATUS FOR CARRYING OUT. THE SAME
Year: 1868

page_text: LETTERS PATENT to Jacob Baynes Thompson, of Horton, near
Slough, in the County of Bucks, for the Invention of "IMPROVE.
MENTS IN COATING IRON AND STEEL WITH GOLD, SILVER, AND COPPER, AND
IN APPARATUS FOR CARRYING OUT. THE SAME."
Scaled the 17th October 1868, and dated. the 14th August 1868.
PROVISIONAL SPECIFICATION left by the said Jacob Baynes Thompson
at the Office of the Commissioners of Patents, with his Petition,.
on the 14th August 1868...
I, JACOB BAYNES THOMPSON, of Horton, near Slough, in the County:
of Bucks, do hereby declare the nature of the said Invention for
"IMPROVEMENTS IN COATING IRON AND STEEL WITH GOLD, SILVER, AND COPPER,
AND IN APPARATUS FOR CARRYING OUT THE SAME," to be as follows:
In coating the baser metals with an adhering covering of silver or
gold the main difficulty is in purifying the surface of the metal to be
coated. This purification, in the case of steel, iron, and cast iron I
effect by means of nascent hydrogen in an alkaline solution.. For.
obtaining this hydrogen in the nascent state I prefer a. solution of.

page_text: hydrated oxide of sodium (of from 2 to 4 lbs. to the gallon of water).
To this solution may be added a small quantity of any of the compound
cyanide salts which will not decompose readily under the action of a
Daniel's battery of three cells; this will improve the solution but it
is not absolutely necessary. This solution is put into a vat of iron
to which the positive pole of a battery is attached. The articles being
first made as clean as possible they are placed in the vat and connected
with the negative pole of the battery, the action of which must be
such that a considerable current of hydrogen is evolved; care should
be taken to keep the solution up to the proper strength. The solution
should be kept at a heat of from 120° to 150° Fahrenheit; and to prevent
what has been called polarization of the articles by any excess of gas
which may be evolved which causes them to become black and prevents
their being thoroughly cleansed the second part of the Invention is
necessary.
When the articles have been in this vat from 1 to 4 hours
according to circumstances they are transferred to the silvering or
gilding vat and coated in the usual way.
The second part of the Invention relates to the furnace and vat.
in which the cleansing solution is worked. The most suitable vat is
an oblong iron vessel to which is connected a furnace and boiler.
The boiler is an upright one of the same height as the vat and on the
same level, made to hold two or three gallons, and connected with the
vat near the bottom by means of a pipe of suitable bore and also by
another pipe near the top of the same bore. These pipes are of such
a length that the vat is about two feet from the furnace. The action of
the boiler and vat is this, that when the solution is heated in the
boiler it commences to circulate in the vat, a current flowing from
the vat into the boiler at the bottom and from the boiler into the
vat at the top as long as the heat is applied.
The third part of the Invention relates to the burning in of the silver
and gold into the iron or steel. This is performed by means of an
apparatus of the following construction-In the centre of a furnace
is placed a melting pot of cast iron or other suitable material of a
size suitable to the work to done. The bottom of this melting pot
rests on the bottom of the furnace, and the fire is made round, it so
that the heat may be equal or nearly so in all its parts. Within this
melting pot is kept melted lead or an alloy of lead of a heat suitable
for tempering steel into which the articles are plunged and then

page_text: quenched in water. The burning in of the silver may be performed
by means of the flame of a blow pipe or other suitable flame, but
the furnace is preferred for that purpose.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Jacob Baynes Thompson in the Great Seal Patent
Office on the 2nd November 1868.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JACOB
BAYNES THOMPSON, of Horton, near Slough, in the County of Bucks,
send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Fourteenth day of August, in the year.
of our Lord One thousand eight hundred and sixty-eight, in the thirty-
second year of Her reigu, did, for Herself, Her heirs and successors, give
and grant unto me, the said Jacob Baynes Thompson, Her special licence
that I, the said Jacob Baynes Thompson, my executors, administrators,
and assigns, or such others as I, the said Jacob Baynes Thompson, my
executors, administrators, and assigns, should at any time agree with,
and no others, from time to time and at all times thereafter during
the term therein expressed, should and lawfully might make, use,
exercise, and vend, within the United Kingdom of Great Britain and
Ireland, the Channel Islands, and Isle of Man, an Invention for
"IMPROVEMENTS IN COATING IRON AND STEEL WITH GOLD, SILVER, AND COPPER,
AND IN APPARATUS FOR CARRYING OUT THE SAME," upon the condition
(amongst others) that I, the said Jacob Baynes Thompson, my executors
or administrators, by an instrument in writing under my, or their, or
one of their hands and seals, should particularly describe and ascertain:
the nature of the said Invention, and in what manner the same was
to be performed, and cause the same to be filed in the Great Seal
Patent Office within six calendar months next and immediately after
the date of the said Letters Patent.
NOW KNOW YE, that I, the said Jacob Baynes Thompson, do
hereby declare the nature of my said Invention, and in what manner
the same is to be performed, to be particularly described and ascertained
in and by the following statement thereof, that is to say:-

page_text: In coating the baser metals with an adhering covering of silver, gold,
or copper the main difficulty is in purifying the surface of the metal
to be coated. This purification in the case of steel, iron, and cast-iron
I effect by means of nascent hydrogen in an alkaline solution. For
obtaining this hydrogen in the nascent state, I prefer a solution of.
hydrated oxide of sodium (of from 2 to 4 lbs. to the gallon of water).
To this solution may be added a small quantity of any of the compound
cyanide salts which will not decompose readily under the action of a
Daniel's battery of three cells, this will improve the solution but it
is not absolutely necessary. This solution is put into a vat of iron
to which the positive pole of a battery is attached. The articles being
first made as clean as possible they are placed in the vat and connected
with the negative pole of the battery, the action of which must be
such that a considerable current of hydrogen is evolved. Care should
be taken to keep the solution up to the proper strength. The solution
should be kept at a heat of from 120° to 150° Fahrenheit, and to prevent
(what has been called) polarization of the articles by any excess of
gas which may be evolved, which causes them to become black and
prevents their being thoroughly cleansed, the second part of the Invention
is necessary. When the articles have been in this vat from 1 to 4
hours according to circumstances they are transferred to the silvering,
gilding, or coppering vat and coated in the usual way.
The second part of the Invention relates to the furnace and vat in
which the cleansing solution is worked. The most suitable vat is an
oblong iron vessel to which is connected a furnace and boiler. The
boiler is an upright one of the same height as the vat, and on the
same level, made to hold two or three gallons, and connected with the
vat near the bottom by means of a pipe of suitable bore and also by
another pipe near the top of the same bore. These pipes are of such
a length that the vat is about two feet from the furnace. The action
of the boiler and vat is this, that when the solution is heated in the
boiler it commences to circulate in the vat, a current flowing from
the vat into the boiler at the bottom and from the boiler into the
wat at the top as long as the heat is applied.
The third part of the Invention relates to the burning in of the
silver, gold, or copper into the iron or steel. This is performed by
means of an apparatus of the following construction:-In 'the centre
of a furnace is placed a melting pot of cast iron or other suitable

page_text: material of a size suitable to the work to be done. The bottom of
this melting pot rests on the bottom of the furnace, and the fire is
made round it so that the heat may be equal or nearly so in all its
parts. Within this melting pot is kept melted lead or an alloy of
lead of a heat suitable for tempering steel, into which the articles are
plunged and then quenched in. water. The burning in of the silver
may be performed by means of the flame of a blowpipe or other
suitable flame but the furnace is preferred for that purpose.
And having now described the nature of my said Invention, and in
what manner the same is to be performed, I declare that what I
claim is,―
Firstly. The purifying of the surface of iron or steel before being
coated with gold, silver, or copper by means of nascent hydrogen from
an alkaline solution substantially as herein-before described.
Secondly. The construction or arrangement, substantially as herein-
before described, of the furnace and vat in which the purification of
the surface of the iron or steel is performed.
Thirdly. The burning in of the gold, silver, or copper into the iron
or steel, and the construction of the furnace and the employment of
melted metal in which the burning in is performed substantially as
herein-before described.
In witness whereof, I, the said Jacob Baynes Thompson, have
hereunto set my hand and scal, this Twenty-ninth day of October,
in the year of our Lord One thousand eight hundred and sixty-
eight.