IMPROVEMENTS IN THe Manu- FACTURE OF METAL
Year: 1871

page_text: LETTERS PATENT to Frank Alexander Marshall, of Berwick-upon-
Tweed, Engineer, for the Invention of "IMPROVEMENTS IN THe Manu-
FACTURE OF METAL."
Sealed the 16th April 1872, and dated the 19th October 1871.
PROVISIONAL SPECIFICATION left by the said Frank Alexander
Marshall at the Office of the Commissioners of Patents, with his
Petition, on the 19th October 1871.
I, FRANK ALEXANDER MARSHALL, of Berwick-upon-Tweed, Engineer,
do hereby declare the nature of the said Invention for "IMPROVEMENTS
IN THE MANUFACTURE OF METAL," to be as follows:-
I take about equal proportions of grey, mottled, and white iron, these
are melted by the ordinary mode in a reverbatory furnace and treated
with about ten pounds of sulphate of iron and about six pounds of
oxide of manganese to the ton of iron while in a molten state. The

page_text: proportions of sulphate of iron and oxide of manganese I vary
according to the quality of iron under operation. It is then run off,
and if the result is not satisfactory in producing sufficient whiteness and
density, the metal is mixed with other iron and treated a second time
in the reverbatory furnace with either oxide of iron or black oxide of
manganese, but I find in practice it is not generally necessary to use
both, though under certain circumstances it may be desirable particularly
where carbon is perceptibly too free. After the fluid metal has been
allowed to remain in the furnace from twenty minutes to half an hour,
according to the condition of the metal, i.c. as soon as it gets thick and
inclined to be pasty, it is in a fit state to be run into plate or pig
moulds.
If the result of the first process is satisfactory I omit the second
melting as above described. The metal so obtained either from the
first or second process is then broken up small by a steam hammer or
other proper appliance, and those portions which are perfectly free from
core or kish are picked out by hand and remclted in crucibles, where it
is again heated with about two ounces to the hundredweight of metal
of a mixture of sulphate of zinc and antimony. The result is the
production of an almost absolutely pure metal of greater hardness and
density than that obtained by any known process. It is antifrictional,
particularly suiting it for bearings and frictional parts of machinery, and
other purposes requring a hard indestructible metal, and possessing the
great advantages of being far more durable and supplied at much less
cost than other metals or amalgams at present in use for such purposes.
The refuse after the picking out as above described is available for
re-melting in the reverbatory furnace mixed with fresh untreated iron
in manner described.
I claim as my Invention the first, second, and third of the above
described processes, and the production and application of metal obtained
thereby to or for the purposes respectively above described or any
purpose of a similar nature to which the same is or may be applicable.
I do not claim as part of my Invention the apparatus used in any of
the above processes.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Frank Alexander Marshall in the Great Seal Patent
Office on the 19th April 1872.
TO ALL TO WHOM THESE PRESENTS SHALL COME I, FRANK
ALEXANDER MARSHALL, of Berwick-upon-Tweed, Engineer, send
greeting.
г
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Nineteenth day of October, in the year
of our Lord One thousand eight hundred and seventy-one, in the thirty-
fifth year of Her reign, did, for Herself, Her heirs and successors, give
and grant unto me, the said Frank Alexander Marshall, Her special
licence that I, the said Frank Alexander Marshall, my executors,
administrators, and assigns, or such others as I, the said Frank Alex-
ander Marshall, my executors, administrators, and assigns, should at any
3 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 METAL," upon the con-
dition (amongst others) that I, the said Frank Alexander Marshall, my
executors or administrators, by an instrument in writing under my or
their, or one of their hands and seal, 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
5. 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 Frank Alexander Marshall, 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
oin and by the following statement :—
I take about equal proportions of grey, mottled, and white iron, these
are melted by the ordinary mode in a reverbatory furnaco and treated
with about ten pounds of sulphate of iron and about six pounds of
oxyde of manganese to the ton of iron while in the molten state. These

page_text: * should be well stirred into the metal and afterwards allowed to stand in
the well of the furnace about twenty minutes with the damper lowered.
Should a larger proportion of grey pig iron than of the other descrip-
tion be used a proportionally larger quantity of oxide of manganese
must be employed, but if on the other hand white iron predominates in
the mixture then more sulphate of iron should be used. When the metal
has stood sufficiently it is then run off, and if the result is not satisfactory
in producing sufficient whiteness and density, the metal is mixed with
an addition of about one-fifth part its weight of mottled iron and
treated a second time in the reverbatory furnace with five pounds of
oxide of iron and five pounds of black oxide of manganese, but I find
in practice it is not generally necessary to use both, though under
certain circumstances it may be desirable particularly where carbon is
perceptibly too free. After the fluid metal has been allowed to remain-
in the furnace from twenty minutes to half an hour, according to the
condition of the metal, i.e. as soon as it gets thick and inclined to be
pasty, it is in a fit state to be run out into plate or pig moulds.
. If the result of the first process is satisfactory I omit the second
melting as above described. The metal so obtained either from the first
or second process is then broken up small by a steam hammer or other
proper appliance, and those portions which are perfectly free from core
or kish are picked out by hand and re-melted in crucibles, where it is
again treated with about two ounces to the hundredweight of metal of a
mixture of sulphate of zinc and antimony.. The result is the production
of an almost absolutely pure metal of greater hardness and density than
that obtained by any known process. It is antefrictional, particularly
suiting it for bearings and frictional parts of machinery and other
purposes requiring a hard indestructible metal, and possessing the great
advantages of being far more durable and supplied at much less cost
than other metals or amalgams at present in use for such purposes.
The refuse after the picking out as above described is available for
re-melting in the reverbatory furnace mixed with fresh untreated iron,
in manner described.
I claim as my Invention the first, second, and third of the above
described processes, and the production and application of metal obtained
thereby to or for the purposes respectively above described or any
purpose of a similar nature to which the same is or may be applicable.

page_text: I do not claim as part of my Invention the apparatus used in any of
the above processes.
In witness whereof, I, the said Frank Alexander Marshall, have
hereunto set my hand and seal, this Nineteenth day of April,
in the year of our Lord One thousand eight hundred and seventy-
two.
Signed, scaled, and delivered
by the within named Frank
Alexander Marshall, in the
presence of
H.T. WESTON,
FRANK A. MARSHALL. (L.S.)
Clerk to Messrs. Phillips & Son,
Solicitors,
11, Abchurch Lane, E.C.