AN IMPROVE- MENT IN COATING IRON NAILS, SCREWS, NUTS, BOLTS, AND OTHER ARTICLES MADE OF IRON WITH OTHER METALS
Year: 1843

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, we, BENJAMIN
BRUNTON BLACKWELL, of Newcastle-upon-Tyne, Gentleman, and WILLIAM
NORRIS, of the City of Exeter, Civil Engineer, send greeting.
WHEREAS Her present most Excellent Majesty Queen Victoria, by Her
Letters Patent under the Great Seal of Great Britain, bearing date at West-
minster, the Twenty-first day of February, in the sixth year of Her reign, did,
for Herself, Her heirs and successors, give and grant unto us, the said
Benjamin Brunton Blackwell and William Norris, Her especial licence, full
power, sole privilege and authority, that we, the said Benjamin Brunton
Blackwell and William Norris, our exors, adiñors, and assigns, or such others
as we, the said Benjamin Brunton Blackwell and William Norris, our exors,
admors, or assigns, should at any time agree with, and no others, from time
tó time and at all times thereafter 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, our Invention of "AN IMPROVE-
MENT IN COATING IRON NAILS, SCREWS, NUTS, BOLTS, AND OTHER ARTICLES MADE
OF IRON WITH OTHER METALS;" in which said Letters Patent is contained a
proviso, that we, the said Benjamin Brunton Blackwell and William Norris, or
one of us, shall cause a particular description of the nature of our said Inven-
tion, 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 date of the said in part recited Letters Patent, as in

page_text: 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, we, the said
Benjamin Brunton Blackwell and William Norris, do hereby declare that the
nature of our said Invention, and the manner, in which the same is to be
performed, are particularly described and ascertained in and by the following
statement thereof (that is to say):-
Whereas it has been found that when articles of iron have been coated with
copper in solution by a galvanic process, as is now well understood, the iron is
liable to be corroded, and that frequently an oxide of iron is, either during the
operation or in the course of time afterwards, formed on the surface of the
iron under the copper coating, to the manifest injury of the articles so coated.
Now, our improvement consists of subjecting iron nails, screws, nuts, bolts,
and other articles made of iron, to be coated with copper by galvanic means,
after the articles of iron have been first case-hardened, or previously coated
with lead or an alloy of lead.
Our first method is by case-hardening the iron articles, whereby the surface
is rendered much less electro-positive to copper, less liable to oxidation, and
in a better state for receiving a sound; 'firin, and ductile coating of copper.
This may be done by any of the known methods of case-hardening. The
method which we prefer is, first to remove from the surface of the articles by
the usual methods any scale which may adhere thereto, then placing them with
a portion of parings of hoof or horn, or bone dust, in a crucible or iron box
well luted, and subjecting them to a red heat. This process being well known,
need not be more, particularly described, the only difference between this
and case-hardening for any other purpose being that the goods, especially if
consisting of small articles, such as nails, must be removed so soon as a very
thin film of case-hardened surface is obtained, otherwise they are rendered
brittle. For nails, and such like small articles, we find that about three-
quarters of an hour is sufficient; but practice alone can determine the proper
time for each description of goods.
Our second mode consists in covering iron with other metals or alloys, as a
preparation for receiving a coating of copper, by the galvanic battery, whereby
the iron goods are more effectually protected' from corrosion, and much better
surface is obtained for receiving a deposit of copper. The method which we
prefer for this purpose is to clean the articles of iron, and dip them in the
molten metal in precisely the same manner as is known and practised for
covering iron with tin. We do not confine ourselves, however, to this method,
but we consider it the best and the most economical.

page_text: The metals which we prefer for this purpose are, first, lead; secondly, an
alloy of lead, with from one-fifth to one-tenth of tin; thirdly, an alloy consisting
of fifteen parts lead, two parts tin, and one part of antimony; but we do not.
confine ourselves to the above, as other alloys or different proportions may be
used for the same purpose, but we believe not with better effect. After
receiving this first coating, the iron goods are ready to be placed in a solution of
copper, and in the circuit of a galvanic battery, to receive a coating of copper;
and it is much better if the goods be placed in the battery while yet hot from
the first operation, and the battery itself be kept at a temperature between
eighty and a hundred degrees of Fahrenheit, as in this case the operation is
more certain, both as regards the saving of time occupied in depositing the
copper, and the coating itself being found very sound, firm, and ductile.
Having thus described the nature of our said Invention, and the manner of
carrying the same into effect, we would have it understood that what we claim
as our Invention is, the submitting iron or articles of iron to a process of being
coated with copper by galvanic means, after such articles have been case-
hardened, or after they have received a coating of lead or an alloy of lead.
In witness whereof, we, the said Benjamin Brunton Blackwell and
William Norris, have hereunto set our hands and seals, this Eighteenth
day of August, One thousand eight hundred and forty-three.
WILLIAM
(L.S.) NORRIS.
AND BE IT REMEMBERED, that on the Eighteenth day of August, in
the year of our Lord 1843, the aforesaid Benjamin Brunton Blackwell and
William Norris came before our said Lady the Queen in Her Chancery, and
acknowledged the Specification aforesaid, and all and every thing therein
contained and specified, in form above written. And also the Specification
aforesaid was stamped according to the tenor of the Statute made for that
purpose.
Enrolled the Twenty-first day of August, in the year of our Lord One