AN IMPROVED METHOD OF MAKING LETTERS PAT
Year: 1856

page_text: LETTERS PATENT to George Cumming Thomas, of Washington City,
United States of America, but now of 67, Gracechurch Street, in the
City of London, for the Invention of "AN IMPROVED METHOD OF MAKING
LETTERS PATENT to George Cumming Thomas, of Washington City,
United States of America, but now of 67, Gracechurch Street, in the
City of London, for the Invention of "AN IMPROVED METHOD OF MAKING
-A communication from Horace Vaughn, of Providence, Rhode
STEEL.
Island.
Sealed the 27th February 1857, and dated the 3rd September 1856.
PROVISIONAL SPECIFICATION left by the said George Cumming Thomas
at the Office of the Commissioners of Patents, with his Petition, on the
3rd September 1856.
I. GEORGE CUMMING THOMAS, of Washington City, United States of America,
but now of 67, Gracechurch Street, in the City of London, do hereby declare
the nature of the said Invention for "AN IMPROVED METHOD OF MAKING STEEL,"
a communication from Horace Vaughn, of Providence, Rhode Island, to be as
follows:-
I add to molten iron in the melting pot a pulverized compound of chloride
of sodium, bichromate of potash, and prussiate of potash, in proportions varying
according to the quality of the steel to be produced. This compound is stirred
into the molten iron and converts it into steel, which can then be treated in
the usual way. In some cases where extra hardness is required, I contemplate
adding borax to the above composition.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said George Cumming Thomas in the Great Seal Patent Office
on the 3rd March 1857.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, GEORGE
CUMMING THOMAS, of Washington City, United States of America, but now of
67, Gracechurch Street, in the City of London, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Third day of September, in the year of our Lord One
thousand eight hundred and fifty-six, in the year of Her reign, did,
for Herself, Her heirs and successors, give and grant unto me, the said George
Cumming Thomas, Her special licence that I, the said George Cumming
Thomas, my executors, administrators, and assigns, or such others as I, the said
George Cumming Thomas, or 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 "AN IMPROVED
METHOD OF MAKING STEEL," a communication from Horace Vaughn, of Pro-
vidence, Rhode Island, upon the condition (amongst others) that I, the said
George Cumming Thomas, my executors or administrators, by an instru-
ment 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 George Cumming Thomas, 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 :-
It consists in using and adding a composition of chloride of sodium, prus-
siate of potash, and bichromate of potash to molten iron, or in any lower
degree of heating, so that the metal may be penetrated and acted upon by the
compound, whose use is restricted in this Specification to unmanufactured iron
or iron not made up for special use. By this action the particles of the iron
condense, and thus the metal in some cases may be partially but in others is
wholly converted into steel.
This compound is applicable to the metal in the various stages of perfecting
and refining it previous to its preparation for use or consumption from the blast

page_text: furnace to its conversion into steel, or its being cast into forms. It may be
added to the metal by putting them together in the melting chambers by
running the metal into a chamber previously charged with the compound, &
heated to a sufficient degree by placing the balls from the puddling furnace
into a similar chamber, or in any other mode, time, or state of the process,
that experience will prove most suitable for the object, as I do not consider the
mode of applying the composition essential. In these and similar cases I
should use for every forty pounds of metal, one pound of a flux composed of
16 parts by weight of chloride of sodium, 3 parts of prussiate of potash, 1 of
bichromate of potash, and add to it 4 of pulverized charcoal; bone, leather, and
other animal charcoals may be substituted for a portion of the prussiate of
potash, and in such case more chloride of sodium is required to keep up the
flux. The materials are kept at a proper temperature for the requisite time
until the compound has become thoroughly mixed with the iron, and it is
ascertained in the usual way with the aid of practice that the conversion has
taken place as far as required, when the metal is run off or otherwise removed
and treated in the usual manner to be used. By this treatment, it is believed
that a portion of the usual processes in preparing iron and steel may be
dispensed with, and that in the earlier stages the iron will be found sufficiently
refined for many purposes.
This compound may not perhaps be used economically with all kinds of iron,
but with useful result, chiefly with those possessing mineral properties in greater
or less degree destitute of the essentials requisite, or possessed of those dele-
terious to converting them into good steel under the ordinary mode of treat-
ment, such for instance as the iron ore or stone from which most of the English
iron is made.
When Solley, Jinks, Staffordshire, and other similar iron is to be converted
into steel, for every forty-five pounds of metal prepared in the same manner as
Swedish iron for the same purpose, one pound of the compound consisting of
33 parts of chloride of sodium, 9 parts of prussiate of potash, and 3 of
bichromate of potash, is put with it into the melting pot. The whole, together
with 5 ounces of pulverized charcoal, is submitted to the same heat & treat-
ment as Swedish iron, and poured off into ingots, is drawn into shapes for use,
viz., for making cold chisels, plane irons, mortice chisels, and similar tools, and
for general welding purposes. When this iron has been converted into English
blister steel, & this is to be further refined, 14 ounces of the compound, with
2 ounces of manganese, without charcoal is used, and the whole subjected to
the same course; this is best adapted for joiners' chisels, razors, and all tools
made of solid steel not welded. When half converted, generally termed spring

page_text: conversion, is to be refined, the same quantity of the composition with one
ounce of manganese is employed, and a similar course pursued as before. Steel
thus made is best fitted for files, turning tools, &c.
As a general rule, manganese renders the steel harder, and charcoal renders
it tougher.
In hardening and tempering this steel, a low degree of heat must be used,
the metal requiring to be brought to a moderate cherry red color; herein
consists the great difference in working this and steel made from Swedish
iron.
I do not confine myself to the exact quantity of the compound, nor to the
proportions of its several ingredients, as these are be varied to suit the different
qualities of iron, nor to the use always of the prussiate and bichromate together,
as I believe the latter may sometimes be dispensed with, though I prefer to
use both.
Having now described my Invention, what I claim is the use and employ-
ment, substantially as described of the composition, substantially as described,
in its application to iron under the conditions above stated, for the purposes of
refining it or making it into steel.
In witness whereof I have hereunto set my hand & seal, on this Sixteenth
of February, A.D. Eighteen hundred and fifty-seven.
A
GEO. C. THOMAS.
(1.5.)