Improvements in the Production of Ductile Iron from Cast-iron.
Year: 1889

page_text: Date of Application, 5th Nov., 1889
Complete Specification Left, 5th Sept., 1890-Accepted, 31st Jan,, 1891
[Communicated from abroad by STEPHEN HENRY EMMENS, of Emmens, County
of Westmoreland, in the State of Pennsylvania, United States of America,
Engineer.]
Improvements in the Production of Ductile Iron from Cast-iron.
I, HENRY HARRIS LAKE, of the firm of Haseltine, Lake & Co., Patent Agents,
Southampton Buildings, in the County of Middlesex, do hereby declare the nature
of this invention to be as follows:-
This invention relates primarily to a process for producing ductile iron from
ordinary gray, white or mottled pig-iron but the process is also applicable to the
conversion of any other kind of cast-iron, such as, for example, the " scrap " cast-
iron met with in the market.
Cast-iron is a brittle compound of iron with carbon and silicon, and usually
contains sulphur and phosphorus in addition. By removing a portion of these
associated elements from the iron, a ductile metallic body is obtained which is
variously known as wrought iron" homogeneous metal" or mild steel"
according to the degree of purification and which is no longer brittle, but is capable
of being forged and welded.
"
66
The method hitherto employed for converting cast iron into wrought iron, that
is to say, into a ductile metal containing not more than about 0-2 per cent. of
carbon, is the well known puddling process. By this method the cast iron is
melted either on an open hearth or forge (termed a finery") or in a reverberatory
furnace and is then exposed to the action of air and other oxidizing agents, such
as hematite, forge-scale &c. the result being that the carbon and silicon are removed
in the form of carbonie oxide and slag and comparatively pure iron remains.
The conversion of cast iron into steel has hitherto been effected either by a
modification of the puddling process or by blowing air through the molten metal or
by the solution of wrought iron in molten cast iron.
In all of these processes the cast iron is fused before its conversion into wrought
iron or steel and to get the best results from either of the foregoing processes
great care must be exercised in selecting the pig-iron to be treated and most
manufacturers have found it advisable to use several grades of pig iron in certain
definite proportions in carrying out any one process. The puddling process
particularly requires a very high class of skilled labour to make it successful and is
therefore costly.
The object of the present invention is to afford a direct process of conversion of
pig-iron into ductile iron on a commercial scale, and at the same time to render
the process entirely independent of the particular grade or character of the pig-iron
to be used, and to effect the conversion of all grades of pig-iron, no matter how
many or in how great proportion impurities may exist in the same.
By the present invention the fusion of the cast-iron is dispensed with. The
separation of the carbon, silicon, sulphur, and phosphorous is effected by electrolysis,
the invention consisting in making the pig-iron to be converted the anode in a
suitable electrolyte, and then passing an electric current from such anode through
the electrolyte to a suitable cathode. The invention further consists in passing an
electric current through a suitable electrolyte from an anode of pig-iron to a cathode
of ductile iron. The invention further consists in passing an electric current
through a suitable electrolyte from an anode of pig-iron to a ductile sheet iron
cathode. The invention further consists in the commercial production of ductile
iron by electrolytically separating iron from pig-iron, depositing upon an iron cathode
CF-D

page_text: and then heating the cathode and deposited iron to anneal the same and partially
eliminate the occluded hydrogen. The invention further consists in the commercial
production of ductile iron by electrolytically separating the iron from pig-iron,
depositing such iron on a ductile iron cathode, and then in succession heating and
rolling or forging the cathode and deposited iron.
It has long been known that iron may be electrolytically separated from its
solutions, but such electro-deposition of iron has been practised only as a means of
electro-plating already manufactured articles with a coating of refined iron, as, for
example, the facing of copper plates for engraving. In this process the iron pro-
duced is extremely hard, the process itself being known by the French term acierage.
The substance thus obtained appears to be a compound of metallic iron and
hydrogen. For example in the work entitled " Electro-chemistry, Inorganic" by
G. Gore F.R.S. London 1888 page 92 the following statement is made:-
"M. Cailletet states that by electrolysing a solution of ferous chloride mixed
with sal-ammoniac the iron was deposited in the form of mammillary masses,
brittle, brilliant, and hard enough to scratch glass, and the deposit, when plunged
into water, evolved numerous 'bubbles of pure hydrogen. Also that one volume of
the iron absorbed about 240 volumes of hydrogen, which ignited by contact with a
flame and surrounded the metal with a pale colour. (Chem. News Vol. XXXI.
p. 119; also Jour. Chem. Soc. Vol. XIII. p. 425.) According to R. Leng,
deposited iron contains 185 times its volume of hydrogen, chiefly in the layers of
metal first deposited (Chem. News Vol. XXI. p. 179) and Troost and Hautefeuille
say that it sometimes contains as much as 200 times its bulk (Chem. News,
Vol. XXXI. p. 196)."
Prior to the present invention ductile iron does not appear to have been produced
from cast iron by electrolysis. In the text-books on electro deposition great stress
is laid upon the purity of the electrolytes and the anodes. For example in
Urquhart's "Electro-typing "London 1881 page 208 the statement is made that
the iron composing the anode should be as fine as possible. Charcoal iron is
generally employed with the best results" and at page 113 of the same work the
author says
Iron solutions should be added to when iron is required from an anode
of iron as pure as possible. Cast iron should never be employed. Charcoal iron is
the best failing that wrought plates may be used." Again in Watt's * Electro-
deposition London 1889 page 342" a clean anode of charcoal iron is recommended
for the preparation of a solution for electro-plating with iron, and at page 343 of
the same book the anodes used in Jacobi and Klein's process of “depositing iron
upon moulds for reproducing engraved surfaces and for other useful purposes
said to be " large iron plates or bundles of iron wire." The charcoal iron
mentioned in these passages is not "charcoal pig "but is wrought iron produced from
pig iron by refining in what is known as the charcoal hearth" or "charcoal finery"
this product having the reputation of being an especially pure iron, as may be seen
from the following remarks occurring in Payen's Industrial Chemistry London
1878 page 582.
"3
are
"
The charcoal finery employed in South Wales for the production of a superior
kind of iron suitable for the manufacture of tin plate is represented by Figure 401.
It consists of a rectangular hearth formed of cast iron slabs set in brickwork. The
bottom slab is cast hollow in order that it may be kept cool by the circulation of a
current of air through it while the hearth is being worked. The hearth is enclosed
within brick walls and the waste gas from the fire is carried off by a chimney.
Sometimes the pig-iron is heated by this gas, or even melted in a separate furnace
before it is introduced into the finery, the object being to economise fuel and to
expedite the operation. The charcoal finery is now constructed of larger dimensions
than formerly and the pig-iron is first run down under coke so as to obtain it in the
state of white pig iron, which is decarburised by heating it with charcoal in the
finery hearth. When the charge of metal becomes sufficiently malleable, it is
worled under a hammer into a slab-shaped mass called a "stamp" which is then
broken into pieces and a number of them piled upon a kind of shovel are raised to a

page_text: welding heat in the centre of a mass of ignited charcoal, the pile is then again
hammered into slabs; which are reheated, cut up and rolled, first into bars and then
into sheets of the size and thickness required. The fuel employed in producing
malleable iron from pig-iron in this way is almost always charcoal and the opera-
tion is essentially of the same nature as that already described as being carried out
in various parts of the Continent, the superior character of the metal produced and
known as charcoal iron being in all cases chiefly due to the purity of the fuel
employed."
In British Letters Patent No. 1422 April 23rd 1874 to James Noad an electro-
lytic process is specified in which the anode is described as being
6
66
"
Scrap iron,
wrought cast or crude" but even if this ambiguous phrase be read as meaning that
ordinary cast iron may be employed as an anode, it has according to Noad's inven-
and is
tion to be used in combination with a screen charged with charcoal
employed for the production of steel and not ductile iron; the title of the Patent
being Improvements in the manufacture of steel and of dies and other articles in
steel and the " deposition of steel by the means substantially as hereinbefore
described being the claim. In another British Patent No. 1742 June 10 1872
issued to C. A. Faure an electrolytic device for alkali manufacture is described in
which a cast iron anode is used and metallic iron produced therefrom, and the state-
ment is made that the treatment may be used for the purpose of purifying iron."
But the process thus described is only partly electrolytic, consisting first in
chlorinating the cast iron anode, secondly in converting this chloride into oxide by
treatment with lime in a separate vessel and thirdly in reducing such oxide by
metallic sodium electrolytically produced in the cathode compartment of the
original electrolytic vat.
The present invention does not relate to the process of electro-plating, but is
distinguishable therefrom in the fact that it has for its objective point the commercial
manufacture of refined ductile iron from pig iron irrespective of the particular
quality of the latter. Such conversions of pig-iron directly into ductile iron
of a refined character has,
attempted only by,
as before said, hitherto been
the agency of heat and atmospheric air in the puddling or finery furnace, or
one of its modifi-
in the pneumatic process known as the Bessemer process or
cations in all of which latter the pig iron is deprived of its carbon by the
oxidising action of a blast of air forced into the body of the melted pig iron.
By the present process all forms of converting furnaces are dispensed with together
with the high cost of skilled labour required in puddling and as compared with the
pneumatic process, the preliminary fusion of the pig-iron and the enormous cost of
plant required for the subsequent blowing of air into or through the molten pig-
iron are avoided, and instead of incurring these large items of cost the refined iron
is produced directly without heating and without the employment of skilled labour.
The invention is carried into effect in the following manner:
In an electrolytic bath, of any suitable form and dimensions the cast-iron is
placed, preferably in whole pigs and the same is connected with the positive pole of
The pig-iron
a suitable battery or dynamo which furnishes the electric current."
thus acts as the anode of the bath. The cathode is formed of wrought iron pre-
ferably of a refined, quality which can be, in regular practice most conveniently
obtained by rolling down into proper forms some of the ductile iron produced by
this process and is connected with the negative pole of the electric generator. The
anode and cathode being immersed in a suitable electrolyte a sufficient current of
electricity is next caused to traverse the bath from anode to cathode the effect of
which is to cause the iron of the pig-iron to enter into solution while the carbon,
The iron
silicon, sulphur, phosphorous and other impurities remain undissolved.
of the anode is, by the electrolytic action of the current, transferred across the
The iron so deposited is
bath and deposited in a metallic form on the cathode.
frequently magnetic and contains more or less hydrogen occluded in its mass and
is not sufficiently coherent ductile and homogeneous to warrant its direct use for
many purposes. It is therefore taken from the bath to a suitable furnace or other

page_text: apparatus and there heated, preferably to a welding temperature, by which means
the occluded hydrogen is eliminated and the iron is demagnetized. The. heated
metal is then hammered or rolled into any desired form, and by such mechanical
treatment the mass is consolidated into an excellent and very pure quality of refined
ductile iron.
The occluded hydrogen serves a useful purpose in the event of the accidental
presence of sulphur, phosphorous or other impurities in or on the cathode since in
the heating of the latter after removal from the bath the hydrogen will combine
to form sulphuretted hydrogen, phosphoretted hydrogen etc., which will escape into
the atmosphere.
The present invention is not limited to any particular form of bath or to any
particular cast-iron and electrolyte as regards the said. process but the following
details are regarded as preferable that is to say:
First. The anodes should consist of cast iron in which the bulk of the contained
carbon exists in the form of graphite as is seen in gray pig-iron.
This greatly
facilitates the solution of the iron in the bath by exposing a large metallic surface
and by setting up of considerable local galvanic action between the graphite
and the iron.
Secondly. The electrolyte should consist of a nearly saturated solution of
ammonium sulphate and should be protected from the oxidising action of the
atmosphere by a floating layer of paraffine oil or the like.
Thirdly. The operative cathode surface should be considerably smaller than that
of the anode.
The electro-motive force of the current employed will vary according to the
arrangements of the bath the character of pig-iron used as anode, and other con-
ditions which become factors in determining the density of current at any given
time.
Dated 1 1
1000
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, Agents for the Applicant.
COMPLETE SPECIFICATION.
Improvements in the Production of Ductile Iron from Cast-iron.
I, HENRY HARRIS LAKE, of the firm of Haseltine, Lake and Co., Patent Agents,
45, Southampton Buildings, in the County of Middlesex, do hereby declare the
nature of this invention and in what manner the same is to be performed, to be
particularly described and ascertained in and by the following statement:―
:
This invention relates, primarily, to a new process for producing ductile iron
from ordinary gray, white, or mottled pig-iron; but the process is also applicable
to the conversion of any other kind of cast-iron, such as, for example, the
cast-iron met with in the market.
scrap"
Cast-iron is a brittle compound of iron with carbon and silicon, and usually
contains sulphur and phosphorus in addition. By removing a portion of these
associated elements from the iron, a ductile metallic body is obtained, which is
variously known as. wrought iron," homogeneous metal," "mild steel,"
according to the degree of purification, and which is no longer brittle, but is
capable of being forged and welded.
"
or
The method hitherto employed for converting cast-iron into wrought iron, that is
to say, into a ductile metal containing not more than about 02 per cent. of carbon,
is the well-known puddling process. By this method, the cast-iron is melted either
on an open hearth or forge (termed a finery) or in a reverberatory furnace, and
is then exposed to the action of air and other oxidizing agents such as hematite,
forge-scale, and the like, the result being that the carbon and silicon are removed
in the form of carbonic oxide and slag, and comparatively pure iron remains.
The conversion of cast-iron into steel has hitherto been effected either by a

page_text: modification of the puddling process or by blowing air through the molten metal, or
by the solution of wrought iron in molten, cast-iron.
In all of these processes, the cast-iron is fused before its conversion into wrought
iron or steel; and, to get the best results from either of the foregoing processes,
great care must be exercised in selecting the pig-iron to be treated, and most
manufacturers have found it advisable to use several grades of pig-iron in certain
.
definite proportions in carrying out any one process. The puddling process
particularly requires a very high class of skilled labour to make it successful and is
therefore costly.
The object of the present invention is to afford a new direct process of conversion
of pig-iron into ductile iron on a commercial scale, and, at the same time, to render
the process entirely independent of the particular grade or character of the pig-iron
to be used, and to effect the conversion of all grades of, pig-iron, no matter how
many or in how great proportion impurities may exist in the same.
The
By the present invention, the fusion of the cast-iron is dispensed with.
separation of the carbon, silicon, sulphur, and phosphorus is effected by electrolysis,
the invention consisting in making the cast-iron to be converted the anode in a
suitable electrolyte, and then passing an electric current from such anode through
the electrolyte to a suitable cathode.
The electrolyte employed may be any of the known electrolytes in ordinary use
for the electro-deposition of iron, such as for example an aqueous solution of
ammonium chloride and ferrous sulphate. This solution is very suitable and I have
found that the following proportions give good results, namely: 10 ounces of
ammonium chloride and 28 ounces of ferrous sulphate in 4 gallons of water. The
invention further consists in passing an electric current through a suitable
electrolyte from an anode of cast iron to a cathode of ductile iron. The invention
further consists in passing an electric current through a suitable electrolyte from
an anode of cast-iron to a ductile sheet-iron cathode. The invention further
consists in the commercial production of ductile iron by electrolytically separating
iron from cast-iron, depositing the iron upon a suitable cathode and then collecting
and removing such deposit and heating and welding or forging the same.
invention further consists in the commercial production of ductile iron by electro-
lytically separating the iron from cast-iron, depositing such iron on a ductile iron
cathode, and then in succession heating, and rolling or forging such cathode and
deposited iron.
**
1
The
It has long been known that iron may be electrolytically separated from its
solutions, but such electro-deposition of iron has been practised only as a means
of electro-plating already-manufactured articles with a coating of. iron, as, for
example, the facing of copper plates for engraving. In this process, the iron pro-
duced is extremely hard, the process itself being known by the: French term
acierage" i.e. " steeling and in British Letters Patent No. 1422, dated April 23rd,
1874, granted to James Noad, the metal produced by the passage of an electric
current from an iron anode through a solution of iron salts is said to be steel. The
substance thus obtained appears to be. a compound..of metallic iron and hydrogen.
For example, in the work entitled " Electro-Chemistry Inorganic," by G. Gore,
F.R.S., London, 1888, page 92, the following statement is made:-"M. Cailletet
states that by electrolysing a solution of ferrous chloride mixed with sal-ammoniac,
the iron was deposited in the form of manimillary masses, brittle, brilliant and
hard enough to scratch glass, and the deposit, when plunged into water, evolved
numerous bubbles of pure hydrogen. Also that one volume of the iron absorbed
about 240 volumes of hydrogen, which ignited by contact with a flame and
surrounded the metal with a pale colour, (Chem. News, Vol. XXXI. p. 119 also
Jour. Chem. Soc. Vol. XIII. p. 425). According to R. Leng, deposited iron con-
tains 185 times its volume of hydrogen, chiefly in the layers of metal first deposited
(Chem. News, Vol. XXI. p. 179.), and Troost and Hautefeuille say that it some-
times contains as much as 260 times its bulk (Chem. News, Vol. XXXI.
I am not aware that, prior to my present invention, malleable iron has been
p. 196)."

page_text: For
produced from cast-iron by electrolysis. In the 'text-books on "electro-deposition,
great stress is laid upon the purity of the electrolytes and the anodes.
example, in Urquhart's Electro-typing, London, 1881, page 208, the statement is
made that the iron composing the anode should be as fine as possible. Charcoal
iron is generally employed with the best results"; and, at page 113 of the same
work, the author says, Iron solutions should be added to when iron is required
from an anode of iron as pure as possible. Cast-iron should never be employed.
Charcoal iron is the best failing that, wrought plates may be used." Again, in
Watt's Electro-deposition." London, 1889, page 342 "a clean anode of charcoal
iron is recommended for the preparation of a solution for electro-plating with iron,
and at page 343 of the same book, the anodes used in Jacobi and Klein's process
depositing iron upon moulds for reproducing engraved surfaces and for other
useful purposes," are said to be " large iron plates or bundles of iron wire." The
charcoal iron" mentioned in these passages is not charcoal pig; but is wrought
iron produced from pig-iron by refining in what is known as the charcoal hearth,"
or charcoal finery. this product having the reputation of being an especially
pure iron, as may be seen from the following remarks occurring in Payen's
*Industrial Chemistry," London 1878, page 582:-
of "
22
The charcoal finery employed in South Wales for the production of a superior
kind of iron suitable for the manufacture of tin-plate is represented by Figure 401
The fuel employed in producing malleable iron from pig-iron in this
way is almost always charcoal, and the operation is essentially of the same nature
as that already described as being carried out in various parts of the Continent, the
superior character of the metal produced and known as charcoal iron being, in all
cases, chiefly due to the purity of the fuel employed."
66
6
"
In the British Patent to Noad, already referred to, an electrolytic process is
specified in which the anode is described as being scrap iron, wrought, cast or
crude but even if this ambiguous phrase be read as meaning that ordinary cast-
iron may be employed as an anode, it has, according to Noad's invention, to be
used in combination with a screen charged with charcoal" and is employed for
the production of steel and not ductile iron; the title of the Patent being Improve-
ments in the manufacture of steel and of dies and other articles in steel, and
the "
deposition of steel by the means substantially as herein before described,"
being the claim. In another British Patent (No. 1742, June 10, 1872 issued' to
C. A. Faure) an electrolytic device for alkali manufacture is described in which a
cast-iron anode is used and metallic iron produced therefrom, and the statement is
made that the treatment may be used for the purpose of purifying iron." But the
process thus described is chemical rather than electrolytic, consisting first, in
chlorinating the cast-iron anode; secondly, in converting this chloride into oxide
by treatment with lime in a separate vessel; and, thirdly, in reducing such oxide
by metallic sodium electrolytically produced in the cathode compartment of the
original electrolytic vat.
The present invention does not relate to the process of electro-plating, but is
distinguishable therefrom in the fact that it has for its objective point, the com-
mercial manufacture of refined ductile iron from cast-iron irrespectively of the
particular quality of the latter. Such conversion of cast-iron directly into ductile
iron of a refined character has, as before said, hitherto been attempted only by the
agency of heat and atmospheric air in the puddling or finery furnace, or in the
pneumatic process known as the Bessemer process, or one of its modifications, in all
of which latter the cast-iron is deprived of its carbon by the oxidizing action of a
blast of air forced into the body of the melted cast-iron. By the present process
all forms of converting furnaces are dispensed with, together with the high cost of
skilled labour required in puddling; and, as compared with the pneumatic process,
the preliminary fusion of the cast-iron and the enormous cost of plant required for the
subsequent blowing of air into or through the molten cast-iron are avoided, and,
instead of incurring these large items of cost, the refined iron is produced directly
without heating and without the employment of skilled labour.

page_text: My process is partly electrical, partly thermal, and partly mechanical. I
employ electricity to effect the separation of the iron from the silicon, carbon,
sulphur, phosphorus and other impurities present in the compounds known as cast-
iron. I employ heat to dissociate the iron from the hydrogen combined with it
I
during the electrolysis, and also to render it sufficiently ductile for forging.
employ mechanical power to render it compact and fibrous and fit for the market.
I have observed that cast-iron containing a considerable percentage of free carbon
dissolves more readily in an electrolytic bath than cast-iron containing its carbon
principally in a combined condition. This fact I attribute to the local galvanic
action between the carbon and the iron. Hence, the most economical results are
attained with what is known as gray" pig iron.
864
The invention is carried into effect in the following manner:
In an electrolytic bath, of any suitable form and dimensions, the cast-iron is
placed and is connected with the positive pole of the battery or dynamo which
furnishes the electric current. The cast-iron thus acts as the anode of the bath.
The cathode is, preferably, formed of wrought iron of refined quality, which can be,
in regular practice, most conveniently obtained by rolling into proper forms some
of the ductile iron produced by this process, and is connected with the negative pole
of the electric generator. The anode and cathode being immersed in a suitable
electrolyte, a sufficient current of electricity is next caused to traverse the bath
from anode to cathode, the effect of which is to cause the iron of the cast-iron to
enter into solution, while the carbon, silicon, sulphur, phosphorus, and other
impurities remain undissolved. The iron of the anode is, by the electrolytic action
of the current, transferred across the bath and deposited in a metallic form on the
cathode. The iron so deposited is frequently magnetic and contains more or less
hydrogen occluded in its mass, and is too hard and brittle and not sufficiently
coherent, ductile and homogeneous to be marketable. It is, therefore, taken from
the bath to a suitable furnace or other apparatus and there heated, preferably to a
welding temperature, by which means the occluded hydrogen is eliminated and the
iron is demagnetized. The heated metal is then hammered or rolled into any
desired forms, and, by such mechanical treatment, the mass is consolidated into an
excellent and very pure quality of refined ductile iron fit for the market.
The above described process is not confined to any particular form of electrolytic
apparatus; but where the cast-iron to be converted consists of whole pigs the con-
struction and arrangement may preferably be as shown in the accompanying
drawing in which
Figure 1 represents a plan of an electrolytic apparatus, and
Figure 2 a vertical cross section on the line 2. 2. Figure 1.
Like letters of reference indicate corresponding parts in both figures.
The vat of the apparatus consists of a rectangular iron tank, A, open at top, and
provided with longitudinal side-linings B, of wood dipped in melted paraffin.
These linings are provided with cavities C, to catch the carbon, silicon and other
impurities separated from the pig iron anodes D; and the space between the side-
linings forms at bottom a receptacle E, for any iron powder or flakes that may fall
from the cathodes F.
Each of the anodes is provided with a clamp. G, held tightly in place by its
screw H, which carries a projecting nut-receiving bolt I; and each of these bolts I,
rest in a notch J, cut in the top of a connecting bar K. Two of these bars rest
on the upper surface of the side linings B, and are bolted at one end to a cross
bar L, to which the positive pole of the battery or dynamo may be connected in
any suitable manner.
The cathodes F, consist of bars of iron having an effective surface one-fourth the
area of the anodes to which they are respectively opposite, and are suspended by means
This bridge-bar is
of clamp-bolts, M from top-notches N, in a bridge-bar 0.
supported by two notched blocks P, of ebonite or other insulating material, fitted
to the upper edge of the tank at its respective ends, and is connected in any suitable
manner with the negative pole of the battery or dynamo.

page_text: E and 0 Figure 2, represent respectively the electrolyte and a floating layer of
oil thereon, the object of the latter being to protect the iron in solution from the
oxidizing effect of the atmosphere.
The present invention is not limited to any particular form of bath or to any
particular cast-iron and electrolyte regards the said process.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed as communicated to me by
my foreign correspondent I declare that what I claim is:-
First. The process of manufacturing malleable iron from cast-iron, which consists
in passing a current of electricity through a suitable electrolyte from an anode of
cast-iron to a suitable cathode, and then collecting, heating and forging the
deposited iron.
Second. The process of manufacturing malleable iron from cast-iron, which
consists in passing a current of electricity through a suitable electrolyte from an
anode of cast-iron to a cathode of ductile iron, and then heating and forging such
cathode in combination with the iron deposited thereon.
Dated this 5th day of September 1890.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C., Agents for the Applicant.