IMPROVEMENTS IN THE MANU- FACTURE OF CAST IRON
Year: 1855

page_text: LETTERS PATENT to David Simpson Price, of 2, South Moulton Street, in
the County of Middlesex, Consulting Chemist, and Edward Chambers
Nicholson, of 3, Newington Crescent, in the County of Surrey, Manu-
facturing Chemist, for the Invention of "IMPROVEMENTS IN THE MANU-
FACTURE OF CAST IRON."
Sealed the 16th May 1856, and dated the 20th November 1855,
PROVISIONAL SPECIFICATION left by the said David Simpson Price
and Edward Chambers Nicholson at the Office of the Commissioners of
Patents, with their Petition, on the 20th November 1855.
We, DAVID SIMPSON PRICE, of 2, South Moulton Street, in the County
of Middlesex, Consulting Chemist, and. EDWARD CHAMBERS NICHOLSON, of
3, Newington Crescent, in the County of Surrey, Manufacturing Chemist,
do hereby declare the nature of the said Invention for "IMPROVEMENTS IN THE
MANUFACTURE OF CAST IRON " to be as follows:-
This Invention relates to the production of a cast iron of a strength much
superior to that now manufactured, and therefore peculiarly applicable to the
casting of ordnance, girders, &c.
The improvements consist in melting together any kind of grey pig iron with.
the product of the intermediate process in the manufacture of wrought iron
from pig iron, usually termed "metal," "refinery metal," or "finers' metal."
The main object of this Invention is to lower the per-centage of silicon in
cast iron, whilst the total amount of carbon therein remains about the sanie, :

page_text: A somewhat similar result may be obtained by arresting the process of
manufacturing ordinary.grey pig iron into "metal" at a stage when the iron
is similar in properties and chemical composition to that produced by the
the mixture firstly above described..
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said David Simpson Price and Edward Chambers Nicholson in
the Great Seal Patent Office on the 20th May 1856.
TO ALL TO WHOM THESE PRESENTS SHALL COME, we, DAVID
SIMPSON PRICE, of 2, South Moulton Street, in the County of Middlesex,
Consulting, Chemist, and EDWARD CHAMBERS NICHOLSON, of 3, Newington
Crescent, in the County of Surrey,. Manufacturing Chemist, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twentieth day of November, in the year of our Lord
One thousand eight hundred and fifty-five, in the nineteenth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto us, the
said David Simpson Price and Edward Chambers Nicholson, Her special
license that we, the said David Simpson Price and Edward Chambers
Nicholson, our executors, administrators, and assigns, or such others as we,
the said David Simpson Price and Edward Chambers Nicholson, executors,
administrators, or 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 THE MANUFACTURE "OP
CAST IRON," upon the condition (amongst others) that we, the said -David
Simpson Price and Edward Chambers Nicholson, by an instrument in writing
under our 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 we, the said David Simpson Price and Edward
Chambers Nicholson, do hereby declare the nature of our said Invention,
and in what manner the same is to be performed, to be particularly described
and ascertained in and by the following statement:

page_text: Our said Invention relates to the production of a cast iron of a strength and
quality much superior to that now manufactured, and therefore peculiarly
applicable to the casting of ordnance; girders, &c.
The improvement consists in melting together any kind of grey pig iron
with the product of the intermediate process in the manufacture of wrought
iron from pig iron, usually termed "metal," "finers-metal," or "refinery metal."
The object is to lower the per-centage of silicon in cast iron, whilst, the total
amount of carbon therein remains about the same.
The object of our Invention will be understood by a consideration of the
chemical compositions of different varieties of pig iron and metal: The
foreign elements contained in those kinds of pig iron used for foundry purposes
are generally found to be the same.
The quantity in which these elements are present varies according as this
iron has been smelted by the hot or cold blast; with-fossil fuel or charcoal, or to
the nature of the ores; thus, when hot-blast pig iron and cold-blast pig iron are
made from. the same ores, fuel, and flux, the former, or hot-blast pig, iron, is
found to contain a larger amount of silicon and less carbon than the latter, or
cold-blast iron. Charcoal pig iron is. found also to contain less silicon and
sulphur than pig iron smelted by either coal or coke, and this result is quite
independant of the temperature of the blast.
The strength of cast iron is undoubtedly influenced by the greater or less
per-centage of silicon which it contains; this is the impurity generally present
in 'the largest proportions, and perhaps, therefore, influences the quality of
the iron to a greater extent than any other impurity. The product which
we employ in our Invention we find to be freer from impurities, and more
especially from silicon, than either charcoal or coke iron, whilst the amount of
carbon which it contains differs but slightly from that in the pig iron from
which it was manufactured. It is therefore evident, that if-"metal "be
mixed with grey pig iron, the mixture so made will contain less silicon than
the grey pig iron used alone, and that tho per-centage of silicon in this product
will depend upon the relative proportions of metal and pig iron employed; and
further, that an iron, either grey or mottled, can be produced, according to
circumstances.
It will also be obvious, from the above statement, that by employing coal or
coke iron, and "metal" obtained from the same, that a cast iron having the
composition of charcoal iron, as regards its quantity of silicon, may be obtained,
and that by employing charcoal pig iron, and metal made from the same, a
cast iron of exceeding purity will be produced.
We may here observe that we do not confine or restrict ourselves to any

page_text: proportions or to any particular mode of effecting the mixture, which may be
done in the blast furnace, the cupola, air furnace, or otherwise.
The pig iron which we prefer to employ is that which has been smelted by
cold blast from spathu, argillaceous hematite, or magnetic oxide ores, either
alone or mixed, the object being to avoid the presence of too great an amount
of impurities. We also prefer the "metal" to be made from cold-blast
pig iron from the ores above referred to, and to be refined until it has lost
the whole or nearly the whole of its silicon, the object being to lose as littló
carbon as possible.
Having now described and fully ascertained the nature of the said Inven-
tion, and the mode in which the same may be carried into effect, we wish it to
be understood that what we claim as the Invention secured to us by the herein-
before in part recited Letters Patent is, the melting together, in any desired
proportions, any kind of grey pig iron with the product of the intermediate
process in the manufacture of wrought iron from pig iron, usually termed
"metal," "refinery metal," or "finers' metal," for the production of a
superior quality of cast iron.
In witness whereof, we, the said David Simpson Price and Edward
Chambers Nicholson, have hereunto set our hands and seals, the Nine-
teenth day of May, One thousand eight hundred and fifty-six.
:
DAVID S. PRICE.
(L.S.)
E. CHAMBERS NICHOLSON. (L.S.)
Signed, sealed, and delivered in the
presence of
J. HENRY JOHNSON,
47, Lincoln's Inn Fields.