IMPROVEMENTS IN THE
Year: 1865

page_text: LETTERS PATENT to William Robinson, of No. 52, Watling Street, in
the City of London, for the Invention of "IMPROVEMENTS IN THE
PROVISIONAL SPECIFICATION left by the said William Robinson at
the Office of the Commissioners of Patents, with his Petition, on the
18th February 1865.
I, WILLIAM ROBINSON, of No. 52, Watling Street, in the City of London,
do hereby declare the nature of the said Invention for "IMPROVEMENTS IN THE
MANUFACTURE OF IRON AND IN ARTICLES MADE THEREOF," to be as follows:-
This Invention has for its object improvements in the manufacture of iron
and in articles made thereof. For these purposes cast or crude iron at a
suitable temperature is interposed between the poles of permanent or electro-
magnets and is connected thereto, so as to be in metallic contact therewith.
Such cast or crude iron if in a fluid state may be in a furnace ladle or vessel
or in a mould. In certain cases it is preferred to use two or more bar magnets,
and to apply the north pole of one magnet or series of magnets to one side
or end of the iron to be acted on, and the south pole of another magnet or
series of magnets to the opposite side or end of such iron. The other or

page_text: opposite poles of the magnets or series of magnets are to be so connected
as to complete the magnetic circuit. When acting on masses of wrought
iron the magnetic poles are to be put in metallic connection with the opposite
sides or ends of the masses to be acted on in a similar manner as when
treating cast or crude iron.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said William Robinson in the Great Seal Patent Office on the
16th August 1865.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
ROBINSON, of No. 52, Watling Street, in the City of London, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Eighteenth day of February, in the year of our Lord
One thousand eight hundred and sixty-five, in the twenty-eighth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me,
the said William Robinson, Her special licence that I, the said William
Robinson, my executors, administrators, and assigns, or such others as I,
the said William Robinsou, 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 "IMPROVEMENTS IN THE MANUFACTURE OF IRON AND IN ARTICLES MADE
THEREOF," upon the condition (amongst others) that I, the said William
Robinson, my executors or administrators, by an instrument 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 William Robinson, 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 say :-
This Invention has for its object improvements in the manufacture of iron
and in articles made thereof. For these purposes cast or crude iron at a

page_text: suitable temperature is interposed between the poles of permanent or electro-
magnets, and is connected thereto so as to be in metallic contact therewith.
Such cast or crude iron if in a fluid state may be in a furnace ladle or vessel
or in a mould. In certain cases it is preferred to use two or more bar
magnets, and to apply the north pole of one magnet or series of magnets, to
one side or end of the iron to be acted on, and the south pole of another
magnet or series of magnets to the opposite side or end of such iron. The
other or opposite poles of the magnets or series of magnets are to be so con-
nected as to complete the magnetic circuit. When acting on masses of
wrought iron the magnetic poles are to be put in metallic connection with the
opposite sides or ends of the masses to be acted on in a similar manner as
when treating cast or crude iron.
Having thus stated the nature of my Invention, I now proceed to describe
the manner of carrying the same into effect.
In the manufacture of wrought iron from crude metal I, by preference,
use a furnace of ordinary proportions, and of the pattern commonly known
in various districts as a puddling or hammer furnace, having the firing hole
and the working bole both on the same side. On the opposite side of the
furnace I remove the brickwork in two places so as to introduce two masses
or bricks of wrought iron six inches in length and three inches square, so that
their lower edges may be on a level with the sand bed of the furnace, and
their inner surfaces flush with the fire-brick lining thereof, the object being
that at the proper time the mass of molten iron in the furnace may come in
contact with the iron bricks. I then secure the crevices with fire-clay, or
other suitable lute or cement, so as to prevent the efflux of the molten metal.
The distance at which I have placed the two iron bricks apart is one foot and
six inches, but this distance may be varied as herein-after explained. The
ends inside the furnace are to be protected from the heat by a fire-brick, sand,
or other suitable material. I also provide two bar magnets or one horse-shoe
magnet, either electro or permanent. If horse-shoe shape the two opposite
poles must be the same distance apart as the iron bricks, but bar magnets are
more convenient as being capable of adjustment as to distance. I have there-
fore hitherto used bar magnets, and proceed to describe them.
They are of the best soft wrought iron carefully annealed, the form is a
round bar, and the size five feet long and three inches and a quarter in
diameter. On each of these bars is coiled about 600 yards of copper wire
(No. 18 size, properly insulated by covering with cotton,), in the usual manner
for forming an electro-magnet, except that at the-end destined to come. in
contact with the iron bricks as herein-after described, I leave six inches of

page_text: the iron bars totally uncovered, the object being to remove the cotton covering
of the wire from the influence of the heat as much as possible. I then place
the two bar magnets on a table so constructed that the upper board may by
resting on rollers, upright levers, or otherwise, be moved backwards and for-
wards, and in such position as to bring the working ends of the magnets into
contact with the iron bricks before mentioned at the proper time, as herein-
after indicated; and having properly adjusted the distance of the magnets
from each other, so as to correspond with the distance of the iron bricks from
cach other, and with their ends evenly square with each other, I apply a bar
of iron as an armature to the ends furthest from the furnace, and secure each
piece in its place, taking care that the working ends of the magnets project
far enough beyond the edge of the upper board of the table to come in even
contact with the iron bricks when the upper board and magnets are thrust
forward for use, and connect the wires proceeding from the ends of the magnets
furthest from the furnace with each other. Any suitable galvanic or electric
-or voltaic battery may be used for exciting the magnetic power; but for more
fully understanding the nature of my operation I shall describe that which I
have used. It consists of an ordinary copper cauldron twenty-three inches
wide and eighteen deep, in the inside of which I place a circle of zinc, con-
sisting of a plate 4 feet and 6 inches long, and of the same width as the depth
of the cauldron, bent into a circular form, and secured with zinc rivets or
otherwise, and properly amalgamated and fitted with woods at the bottom to
avoid contact with the copper. Inside of this zinc circle I introduce a similar
circle of copper, but smaller, so as to be at every point about 3 inches distant
from the surrounding zinc. This copper cylinder stands on the bottom of the
cauldron without any wood insulator. Inside of this copper cylinder I suspend
a sheet of zinc 9 inches wide, and properly amalgamated, so as not to touch
the surrounding copper at any point. I then by means of binding screws
and wire connect the two pieces of zinc with each other, and the copper
cylinder and cauldron in the same manner, so as to form a battery of one cell
only. I then connect the two metals of the battery with the wires proceeding
from the working ends of the magnets to ascertain that the current flows freely,
at the same time charging the battery with a mixture of one part by measure
of sulphuric acid and ten parts of water till full.
Having ascertained that the battery and magnets are in proper order, I
sever the connection in order to save needless waste of zinc, and proceed as
follows:-
The fire in the furnace being lighted and a suitable heat obtained, I place
on the bearth 4 cwt, of the iron known as "forge pig" and 24 lbs., or there,

page_text: abouts, of iron known as "refined iron" or "finery pig," and melt them
together as quickly as the furnace will do it. The time occupied will depend
on the construction and materials of the furnace, the state of the atmosphere,
the quality of the fuel, and the skill of the fireman. As soon as the iron is
melted and flows freely, the magnets are to be connected with the battery, the
coverings of the iron bricks inside the furnace removed, so as to allow the
molten iron to wash against them, and the magnets are to be moved forward
into contact with the iron bricks. As soon as this is done a lambent blue
flame proceeds from the melted iron, visible chiefly about the sight hole. The
melted iron is then to be moved with an iron or other suitable rod or tool,
gently at first, and afterwards more briskly, when a violent ebullition ensues,
which when it partially ceases is again to be excited by moving the melted
metal. After about ten minutes no more boiling can be excited, and the
metal grows thick. It must then be drawn with an iron raker away from
the contact with the iron bricks in such a way as to allow a fresh portion to
flow in from each side into contact with them. This operation must be
vigorously and rapidly performed, or the metal will ball before it can be all
subjected to this final action of the magnet, which if properly conducted will
occupy about five minutes. The metal then becomes cloggy, like bakers'
dough, and forms a stiffer crust upon its surface. This is to be skimmed off
with a suitable raker, and drawn towards the working hole. A fresh crust
forms as fast as it can be drawn off, and ultimately the whole of the metal
comes into this state. The magnets may then be withdrawn (after separating
them from the battery). The time for this last operation of collecting the
crust depends almost wholly on the skill and industry of the workman, as it
forms as fast as it can be removed. Having thus brought the iron to the
state of bloom, nothing remains but to form it into balls ready for the hammer
in the usual way. When the furnace is larger than the one I have described
two, three, or more pairs of magnets may be necessary, according to the size
of the furnace or quantity of the charge, and when this is the case it is
advisable to separate the individual bars of each pair and their corresponding
iron bricks only nine inches asunder, leaving eighteen inches, or thereabouts,
between each pair of magnets. The furnace I have used is 2 feet 6 inches
square in the bars; the bed is three feet long and 2 feet wide in the clear,
and I consider it desirable that the width should not be increased beyond
three feet, as more conducive to the proper and economical action of the
magnets; but I do not confine myself to any particular dimensions or form
of furnace. The iron thus obtained will be found to be hard and tough and
remarkably dense and heavy. That obtained from the mixture I have

page_text: mentioned partakes largely of the nature of steel; other qualities and
mixtures of crude iron will give results varying according to their several
natures, and they are so numerous that it is impossible to specify for each
separately, particularly as each manufacturing firm has a quality or mixture
which for commercial or other reasons it prefers to any other, but my process
may be applied with advantage to any of them.
When any article is to be cast in iron, and it is desired to communicate a
degree of toughness and malleability thereto, I proceed as follows:-Laving
considered the shape and size of the pattern, it is moulded in the lower box in
the usual way, and when the upper box is put on for moulding the upper
surface, and before the sand is put in, I place on such parts of the pattern as
are uncovered masses of wrought iron so formed that they will not fall ont
from the sand when the top box is removed, the pattern taken from the sand,
and the top box replaced ready for casting. The irons I have used for this
purpose are wedge-shaped, an inch an three quarters long and an inch and a
quarter square at their thicker end and one inch square at their smaller end,
and I find they hold their place very well in the sand. It is to be observed
that in moulding the upper box the thicker end of the iron (which is to be
placed upwards) must not be covered with sand, but left exposed for the
application of the magnet, as hereafter directed, and if one or more horse-shoe
magnets be used their distance must be such as to correspond with that of the
poles of such magnet or magnets. After the mould is thus put together the
metal is run in in the usual way, and as soon as it sets in the "get" or
running hole the magnet or magnets (which may be either permanent or
electro) are to be applied to the iron wedges before mentioned in such way
that the magnetic current may pass through those parts which most require
toughness, although the whole mass of the cast metal will be more or less
influenced according to its proximity to or remoteness from the current. It
is best that the magnets should remain till the casting is cold, but this is not
absolutely necessary. A period of from three to ten minutes after the metal
is set, according to the size of the casting, is sufficient to produce the desired
effect. The castings when taken from the mould will have a singularly bright
and clear surface, and will present in a marked manner the appearance which
in ordinary cast iron indicates extreme hardness and brittleness, but on trial
will be found to be very soft to the file, and to possess a toughness capable of
riveting, and if an experimental bar be thus made it can be forged on the
anvil at about the same heat as cast steel, but cannot bear welding heat.
For these purposes I have used an electro-magnet of the ordinary construction,
and need only, therefore, state its dimensions. It is a horse-shoe shape; the

page_text: iron is round, and one inch in diameter; each limb is four inches long in the
clear, and their distance apart is three inches and three eighths from centre
to centre. I excite it with an ordinary quart battery of Smee's construction,
and I find that it will then support about 35 pounds. This magnet I consider
capable of operating on castings up to about 7 pounds weight. Another and
simpler method of applying the magnet consists in so arranging a single pair
of iron wedges above a side runner in the mould, that all the metal as it runs
shall come in contact with each in succession before it flows into the mould.
As any ordinary moulder can do this I need not describe the way of doing it,
but need only say that the magnet must be set with its poles on the iron
wedges, as before described, and it is immaterial which of the poles of the
magnetic current first meets the flowing metal. The most essential point in
this second method is not to pour the iron too hot, or it will probably boil and
become thick, and so make a porous and bad casting, but if proper precaution
be taken in this respect the operation will be found to answer perfectly well.
A careful workman will soon find the right heat, which as it cannot be
measured, I cannot describe.
When making steel it is only necessary to follow the directions for making
wrought iron so far as to the end of the boiling of the metal and the subsequent
thickening thereof. At this point the magnets are to be withdrawn, the
surface of the metal carefully cleaned from the adhering scum, and if a little
finery cinder or other proper flux be thrown in this operation will be greatly
facilitated. A little more heat will then make the metal flow freely, and it
may as soon as this is the case be run off into ingots, and will be found to be
cast steel, varying of course in quality according to the nature of the crude
iron originally employed, the nature of the fuel used, and the skill and
attention of the workman; but the mixture of iron I have mentioned gives a
steel of exceeding hardness and density, striated in its texture, and capable of
resisting a very severe hammering, being almost incapable of fracture by that
means.
In witness whereof, I, the said William Robinson, have hereunto set
my hand and seal, this Thirty-first day of July, in the year of our Lord
One thousand eight hundred and sixty-five.