A PROCESS FOR CONVERTING IRON INTO STEEL
Year: 1825

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, NATHANIEL
KIMBALL of Jewin Street, Aldersgate Street, London, Merchant, send
greeting.
WHEREAS His present most Excellent Majesty King George the Fourth,
by His Letters Patent under the Great Seal of Great Britain, bearing date
at Westminster, the Thirteenth day of October, in the sixth year of His reign,
did, for Himself, His heirs and successors, give and grant unto me, the said
Nathaniel Kimball, His especial licence that I, the said Nathaniel Kimball,
my exors, adiñors, and assigns, or such others as I, the said Nathaniel
Kimball, my exors, admors, 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, and also in
all His said Majesty's Colonies and Plantations abroad, the Invention of "A
PROCESS FOR CONVERTING IRON INTO STEEL" (being a communication from a certain
Foreigner); in which said Letters Patent is contained a proviso obliging me,
the said Nathaniel Kimball, by an instrument in writing, under my hand and
seal, particularly to describe and ascertain the nature of the said Invention,
and in what manner the same is to be performed, and to cause the same
to be inrolled in His Majesty's High Court of Chancery within six calendar
months next and immediately after the date of the said in part recited
Letters Patent, reference being thereunto had, will more fully and at large
appear.

page_text: NOW KNOW YE, that in compliance with the said proviso, I, the said
Nathaniel Kimball, do hereby declare the nature of the said Invention, and
the manner in which the same is to be performed (that is to say):-
I place the iron to be operated on in the process of converting into steel either
in the ordinary arrangement of furnaces heretofore used for that purpose, or in
any other modification of furnaces wherein the requisite heat may be properly
applied to the purpose of aiding and perfecting the process of cementation or
conversion of iron into steel, the iron being similarly placed 'as.heretofore. I
use a mixture or compound hereafter described instead of charcoal alone, as
in the ordinary method of converting iron into steel; and my improvement
consists in the time I save in converting any given quantity of iron, as well as
the more economical expenditure of fuel or other material incident to the
ordinary process.
.
This mixture, which constitues the basis of my said Invention of a Process
of Converting Iron into Steel, may be also used for converting blades or tools of
any description which are forged of iron into steel; and when applied to such
purpose I recommend their being placed in a receptacle .or box of iron or
other suitable material, and therein arranged with alternate layers of the
compound hereafter described, in which situation they are to be submitted.to
the necessary heat for effecting their conversion, which will be done more
economically than by the process heretofore used or in ordinary practice. But
in the method of using my said Invention of a Process of Converting Iron into
Steel it is also necessary to cover over the box aforesaid with sand or other
-suitable material to exclude the access of common air or other gas which
might impede the process. In the process being conducted on this or any
other arrangent the time required for the conversion of any quantity of iron
must entirely depend on its.substance or thickness, and the nature or purposes
which it is to be applied, all which time or duration of conversion will be
learned by practice, but with me have varied from eight to twenty-eight
hours, according to the substance and nature of the iron operated on. The
mixture I use as a substitute for charcoal (and which mixture, as well as the
combination or compounding of which also constitutes the said Invention of
a "Process for Converting Iron into Steel,") is made as follows:-Take one
ounce of. sal ammonia, one ounce of borax, one ounce of alum, one quart of
fine salt; put them into an iron or other metal vessel; stir them well
together, and heat them till the vessel is red hot and the same ceased to
,smoke, then, after it is cool, pulverize it to a dust. Afterwards take four
quarts of strong soot, two quarts of pulverized burnt leather, two gills of
burnt horse hoof, one pint of fine salt, one quart of vinegar, and two quarts of

page_text: urine; put them into an iron or other metal vessel, stir them well together to
the consistence of mortar, then boil it down, stirring it well till it becomes
perfectly dry like dust; then, after cooling it, take the first-mentioned com-
position and sift it through a fine sieve, mixing it at same time with the
second composition. The mixture is then sifted on to the iron to be converted
into steel in the manner before mentioned.
My experiance has found the above proportions to form a suitable quantity
for converting about one hundredweight of iron of ordinary sizes. And it
may be further stated more specifically that in laying down the alternate layers
of the mixture and metal I begin by first laying down the mixture, then a
layer of iron, then another layer of the mixture, which is covered in as before
mentioned.
In witness whereof, I, the said Nathaniel Kimball, have hereunto set
my hand and seal, this Thirteenth day of April, in the year of our
Lord One thousand eight hundred and twenty-six.
NATHANIEL KIMBALL. (LS.)
AND BE IT REMEMBERED, that on the Thirteenth day of April, in
the year of our Lord 1826, the aforesaid Nathaniel Kimball came before
our said Lord the King in His 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.