IMPROVEMENTS IN THE MANUFACTURE OF IRON
Year: 1875

page_text: LETTERS PATENT to Isaac Lowthian Bell, of Rounton Grange, in
the County of York, for the Invention of "IMPROVEMENTS IN THE
MANUFACTURE OF IRON."
Sealed the 4th January 1876, and dated the 30th October 1875.
PROVISIONAL SPECIFICATION left by the. said Isaac Lowthian Bell
at the Office of the Commissioners of Patents, with his Petition,
on the 30th October 1875.
I, ISAAC LOWTHIAN BELL, of Rounton Grange, in the County of
York, do hereby declare the nature of the said Invention for "Im.
PROVEMENTS IN THE MANUFACTURE OF IRON," to be as follows:-
Hitherto it has been found impracticable to obtain a malleable product
in the Bessemer converter or from the Martin Siemens' furnace from
certain qualities of pig iron.
My improvements consist in taking such iron as it comes from
the converter or furnace, adding to it spiegel iron, and transferring it

page_text: into a puddling furnace, where it is worked either by manual labour or
by mechanical means; the product is finished as puddled iron.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Isaac Lowthian Bell in the Great Seal Patent
Office on the 29th April 1876.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, ISAAC
LOWTHIAN BELL, of Rounton Grange, in the County of York, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Thirtieth day of October, in the
year of our Lord One thousand eight hundred and seventy-five, in
the thirty-ninth year of Her reign, did, for Herself, Her heirs and
successors, give and grant unto me, the said Isaac Lowthian Bell,
Her special license that I, the said Isaac Lowthian Bell, my
executors, administrators, and assigns, or such others as I, the said
Isaac Lowthian Bell, my exccutors, 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 THE MANUFACTURE OF IRON,"
upon the condition (amongst others) that I, the said Isaac Lowthian
Bell, my executors or administrators, by an instrument in writing
under my, or their, or one of their hands and seals, should parti-
cularly 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 Isaac Lowthian Bell, do
hereby declare the nature of the 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

page_text: In the substitution of mechanical for hand puddling in furnaces
known as rotatory considerable difficulty has been experienced in pre-
serving from the action of the heat the lining which serves among other
purposes as a protection to the iron casing of the structure itself.
In a great measure I believe this action to be due to the presence of
silicon in the pig iron under treatment, which being oxidized during
the operation attacks the oxides of iron constituting the lining in
question.
My process consists in submitting crude iron intended to be used in
such furnaces as those described, by preference from the blast furnace
direct to the action of a current or currents of air. This is easily effected
in a piece of apparatus known as the Bessemer converter. The extent
to which this operation has to be carried will depend on the quantity of
silicon contained in the pig iron. When this amounts from 1 to 2 per
cent. I find five minutes' exposure to a blast of 15 to 20 lbs. on the
square inch will suffice.
When the metal has been blown to the extent desired the metal is
passed, by preference it is run, direct into the rotary puddling furnace,
and puddled.
In place of stopping the blowing operation whilst the iron still con-
tains sufficient carbon for puddling the blowing may be carried further,
and the carbon afterwards replaced by adding spiegel iron or other pure
cast iron rich in carbon; this however adds somewhat to the cost of
the process.
It often happens that the relative quantities of silicon and phosphorus
in pig iron are such that before the former can be sufficiently oxidized,
the carbon it contains is burnt off to an extent which interferes with the
subsequent operation of puddling. In such a case the iron in the
puddling furnace comes to nature, as it is termed, before the phosphorus
is properly acidified and removed by the oxide of iron always present.
When therefore it is desired to obtain malleable iron as free as possible
from phosphorus I find it useful to prevent the too rapid expulsion of
the carbon by blowing into the converter along with the blast carbon-
aceous matter, such as ground coke, charcoal, or other similar substance;
or as already explained the carbon may after blowing be replaced by
adding spiegel iron or other pure cast iron rich in carbon. On the
other hand where malleable iron of a hard character is required I

page_text: continue the blast until more or less of the carbon of the pig iron is
expelled, by which means the metal retains more or less phosphorus,
which imparts to it the property of hardness or cold shortness, as it is
termed.
What I claim is the manufacture of iron substantially as described.
In witness whereof, I, the said Isaac Lowthian Bell, have here-
unto set my hand and seal, this Twenty-eighth day of April,
in the year of our Lord One thousand eight hundred and seventy-
six.
I. LOWTHIAN BELL. (L.S.)