IMPROVEMENTS IN OBTAINING MOTIVE POWER
Year: 1852

page_text: LETTERS PATENT to William Henry Fox Talbot, of Lacock Abbey,
in the County of Wilts, for the Invention of "IMPROVEMENTS IN
OBTAINING MOTIVE POWER."
Sealed the 2nd February 1853, and dated the 13th December 1852.
PROVISIONAL SPECIFICATION left by the said William Henry
Fox Talbot at the Office of the Commissioners of Patents, with
his Petition, on the 13th December 1852.
I, WILLIAM HENRY FOX TALBOT, of Laycock Abbey, in the County
of Wilts, do hereby declare the nature of the said Invention for
"IMPROVEMENTS IN OBTAINING MOTIVE POWER" to be as follows: -
This Invention is a new kind of electro-magnetic machine, which
may be briefly thus described.
A heavy iron cylinder is made to roll upon a long but narrow
metallic table or plate, close beneath which a long row of horse-shoe
electro-magnets is placed. These magnets stand vertically with
their poles uppermost, so that as the cylinder rolls along the plate,
it unites the two poles of each magnet consecutively. If the magnets
are placed close enough together and on a level with each other,
their summits will form a sufficiently firm surface for the purpose

page_text: required. The machine is so contrived that the cylinder is always
attracted forwards till it reaches the end of the row of magnets; the
action is then reversed, and it returns in the opposite direction till
it reaches the other end, and so on. The whole distance traversed
by the moving cylinder makes one stroke of the engine. The
cylinder communicates its force and motion to the rest of the
machinery, by its axis being attached to a crank and fly wheel.
The motion of the cylinder itself sets in action the contrivance
(sometimes called a commutator, sometimes a rheotome), which
magnetises the magnets that are before the cylinder, and unmag-
netises those behind it.
SPECIFICATION in pursuance of the conditions of the Letters
Patent, filed by the said William Henry Fox Talbot in the Great
Seal Patent Office on the 13th June 1853.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I,
WILLIAM HENRY FOX TALBOT, of Lacock Abbey, in the County of
Wilts, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Thirteenth day of December, in the
year of our Lord One thousand eight hundred and fifty-two, in
the sixteenth year of Her reign, did, for Herself, Her heirs and
successors, give and grant unto me, the said William Henry Fox
Talbot, Her special licence that I, the said William Henry Fox Talbot,
my executors, administrators, and assigns, or such others as I, the
said William Henry Fox Talbot, 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 OBTAINING MOTIVE
POWER," upon the condition (amongst others) that I, the said
William Henry Fox Talbot, by an instrument in writing under my
hand and seal, should particularly describe and ascertain the nature

page_text: of the said Invention, and in what manner the same was to be per-
formed, and cause the saine 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 Henry Fox Talbot, do
hereby declare the nature of the said Invention, and in what manner
the same is to be perforined, to be particularly described and ascer-
tained in and by the following statement thereof (that is to say):
This Invention is a new kind of electro-magnetic machine, which
may be briefly thus described.
A heavy iron cylinder is made to roll upon a long but narrow
metallic table or plate, close beneath which a long row of horse shoc
electro-magnets is placed. These magnets stand vertically with
their poles uppermost, so that as the cylinder rolls along the plate,
it unites the two poles of cach magnet consecutively. If the magnets
are placed close enough together, and on a level with each other,
their summits will form a sufficiently firm surface for the purposc
required. The machine is so contrived that the cylinder is always
attracted forwards till it reaches the end of the row of magnets; the
action is then reversed, and it returns in the opposite direction till
it reaches the other end, and so on. The whole distance traversed
by the moving cylinder makes one stroke of the engine. The cylinder
communicates its force and motion to the rest of the machinery, by
its axis being attached to a crank and fly wheel. The motion of the
cylinder itself sets in action the contrivance (sometimes called a
commutator, sometimes a rheotomc), which magnetises the magnets
that are before the cylinder, and unmagnetizes those behind it.
Having thus given a general description of my Invention in my Pre-
liminary Specification, I now proceed to describe it more particularly.
A (Figure 1), is a rectangular horizontal plate of metal, or table
of wood, whose length considerably exceeds its breadth; B, is a
hollow iron cylinder, which rolls along the middle of the table back-
wards and forwards from end to end, being retained in its true path
by proper guides; C, C, is the axis of this cylinder, the two ends of
which unite with a crank rod R, of considerable length, connected

page_text: with a crank on the axis of a vertical fly wheel, whose plane is
parallel to the longer side of the table. Now supposing the fly wheel
to be moved by hand, its revolution will draw the cylinder backward
and forward from end to end of the table, supposing the crank suf-
ficiently long and adapted to this purpose; but if, on the contrary,
the motive power resides in the cylinder, as it does in this engine,
then the motion of the cylinder from end to end of the table will
cause the fly wheel to revolve.
The motion of the cylinder is effected as follows:- A number of
equal and similar horse shoe electro-magnets are placed vertically
beneath the table and let into it, so that their poles or ends are
brought level with the upper surface of the table. Their north
poles N1, N2, N3, &c., form a row on one side, and their south
poles S1, S2, S3, &c., form a row on the other side of the middle of
the table (Figure 1). As the cylinder rolls on the table, it first
comes into contact with the two poles N₁, S₁, of the first electro-
magnet; then quitting these, it comes into contact with the two poles
No, S2, of the second electro-magnet, and so on. These being
electro-magnets and not permanent magnets, the attraction which
may be exerted by them on the cylinder depends entirely on the
action of the commutator, which term I employ to denote the con-
trivance or instrument employed to change the direction of the
galvanic currents. Now the commutator of this engine, if so con-
trived that the cylinder is not attracted by the poles of the magnet
with which it is actually in contact, but by the poles of the next
magnet. Suppose, for instance, that the cylinder is actually in con-
tact with N, So, the poles of the second inagnet, at that moment
the commutator las magnetised the third magnet, leaving the second
one inert; consequently the cylinder moves on towards the third
magnet, and so on till it reaches the end of the row of magnets, and
begins to return. If the same commutator were now to remain in
use, it would check and retard the motion of the cylinder; a differ-
ent one is therefore employed during the return of the cylinder,
which always magnetizes the magnet next to the cylinder, but on
the other side of it to what was done previously. Hence, it is evident

page_text: that in describing the mode of action of this engine, the attention
must chiefly be fixed upon the construction of the commutators
which have to perform these complicated alterations of the galvanic
currents. In order, therefore, to explain the action of the commu-
tators, I will suppose the table A (Figure 1), to be surrounded on
all sides by a broad horizontal margin of wood M, N, O, and I shall
divide the description of the mechanism employed to change the
galvanic currents into several parts-viz., the polar connecting piece,
the electrodes and their ends, the helix ends, and the two travelling
commutators. A galvanic battery of any common construction may
be employed. The wires proceeding from the two ends of the
battery are let into a thin rectangular tablet of wood T (Figure 2),
and terminate in two broad metallic discs D, D¹, separated from each
other by the wood. These discs are on a level with the lower
surface of the tablet T, which I call the polar connecting piece. The
wooden margin M, on the left side of the table, has let into it, level
with its surface, two long strips of metal U, U, which I call the left
hand electrodes; these when they reach the end of the margin at M³,
are bent below it, which is expressed in the figure by dotted lines,
and brought up again at the front part O, of the margin, where they
terminate in two round metallic discs E, E, level with the surface O.
Similarly the margin N, on the right side of the table has let into it,
level with its surface, two strips of metal V, V, which I call the
right hand clectrodes. These when they reach the end of the margin
at N', are bent below it, and brought up again at the front part O,
of the margin, where they terminate in two round metallic discs
F, F, level with the surface O, and placed parallel to the discs E, E',
but at the distance of one or two inches from them. The discs E, E¹,
are as far apart from each other as the discs F, F', and also as the
discs D, D¹, in Figure 2. Care must be taken that none of the
electrodes touch each other in any part. The battery being placed at
any convenient distance, the polar connecting piece T, which I have
described, is placed on the front part O, of the margin of the table
in such way that its discs D, D', fall on the discs E, E'; consequently
metallic contact is established, and the metallic strips on the left side
of the table become in fact, as I have named them, electrodes of the

page_text: battery or terminations of its wires. The connecting piece T, has its
surface always in contact with that of the margin O, but is capable
of being moved backward and forward in a straight line, being
retained in its path by guide pieces of wood at its sides. When it
is pushed forward, its discs D, D', quit contact with the discs E, E',
and come into contact with the discs F, F'; by which means the
metallic strips on the right side of the table become the acting elec-
trodes of the battery, those on the left side at the same time ceasing
to be so.
This shifting of the connecting picce T, from one position
to the other occurs once in each stroke of the engine, and that not
gradually but rather suddenly, which is accomplished by the fol
lowing simple contrivance; the connecting piece T, has a knob or
button X, on it, and the axis of the cylinder carries a long wire W,
parallel in its direction to the stroke of the engine, and having on
it two lateral hooks Z, Z, nearly as far apart as the length of the
engine stroke. When the cylinder has nearly reached the end of its
excursion in one direction, one of these hooks Z, catches against the
button X, on the tablet T, and pushes it from one of its situations
to the other, and leaves it there. The button lying between the
hooks is not affected by the motion of the wire until the cylinder
has nearly reached the opposite extremity of its excursion, when the
other hook Z¹, catches against the button, and pushes the tablet back
into its first situation. Thus nearly at the end of each stroke of
the engine, the position of the tablet is rather suddenly altered, and
thereby one set of electrodes are thrown out of action and the other
set are thrown into action.
I now come to describe the arrangement of what I call the
helix ends; each electro-magnet is surrounded by a helix of copper
wire in the usual way. Let the two ends of this wire be called
P and Q; the wire P, is bifurcated, or divided into two parts, of
which one goes to the left side, the other to the right side of the
table, and each terminates in a metallic disc P, and P¹, in the
wooden margin of the table. The surface of these discs is level
with the surface of the wooden margin. Similarly the wire Q, is
divided into two parts, one of which goes to the left side, the other
to the right side of the table, and each terminates in a metallic disc.

page_text: Q, and Q. The discs P, and Q, are placed beside each other, but care
must be taken that they do not touch, and likewise that none of the
helix wires touch each other or touch the electrodes; all must be
insulated from each other by the interposition of wood or otherwise.
Similarly the discs P and Q¹, are placed beside each other; the same
arrangement is effected for each of the other magnets. The result
is that between the two strips of metal, which I have called the elec-
trodes, on the left side of the table, there is a double row of metallic
discs viz., P, P, P, &c., Q, Q, Q, &c.; and that similarly between
the two electrodes on the right side of the table, there is a double
row of discs viz., P', P', P¹, &c., Q', Q1, Q, &c.
-
I come now to describe the two travelling commutators. Each
of these being similar, it will be sufficient to describe one of them.
The axis of the cylinder carries an arm oblique to the horizon, and
long enough to reach the margin of the table. This arm terminates
in a small wooden tablet G, Figure 3, which is pressed flat down on
the surface of the margin of the table by means of a spring, and
since the motion of the axis of the cylinder is parallel to the surface
of the table, the commutator travels backward and forward upon
the margin of the table, continually touching its surface. The con-
struction of the commutator will be understood from Figure 3,
where G, is the commutator, made of wood; H, I, are two pieces of
metal let into it, level with its lower surface, and insulated from each
other by wood. In order to understand its action, I must recall
what has been said before, confining my attention at present exclu-
sively to the leftside of the table. The table margin M, Figure 1,
contains two metallic strips or electrodes U, U₁, and between them
two rows of metal discs P, P, P, and Q, Q, Q.
Now suppose the galvanic battery to be in action, and that the
polar connecting piece T, is in such a situation that these electrodes
are in connection with the battery; then, since there is as yet
no connection between the electrodes and the electro-magnets,
none of them are magnetized. Now let the commutator be placed
upon the margin in a line with any two of the discs P, and Q. I
have explained that the commutator contains two metallic pieces H,
and I (Figure 3); of these the piece H, falls partly upon one of the

page_text: electrodes U, and partly on the disc P, bringing them into metallic
connection, while the other piece I, falls partly upon the other elec-
trode U¹, and partly upon the disc Q, bringing them into metallic
connection. The consequence of this is, that the electro-magnet,
corresponding to P, and Q, is magnetized. In order to see this, it
will be sufficient to trace the course of the galvanic current. Issuing
from one end of the battery, it passes through the disc D', in the
polar connecting piece T, Figure 2, thence into the disc E¹, Figure
1, which is the end of the electrode U, then through that electrode
and through the metallic piece H, in the commutator; it enters the
disc P, which is the end of the helix surrounding one of the magnets.
It then traverses the whole of that helix, and comes out at its other
end- viz. the disc Q. From thence it enters the other inetallic piece
I, in the commutator, and from thence it enters the other electrode
U', which ends in the metallic disc E; from thence it enters the disc
D, in the polar connecting piece T, Figure 2, which conducts it to
the other end of the battery. Therefore the galvanic current is
complete, and therefore the electro-magnet is magnetised. I have
explained that the arm carrying the commutator has a certain obli-
quity; this is in order that it may not magnetize the inagnet with
the poles of which the cylinder is actually in contact, but the one
next in order. The cylinder under the influence of this attraction
moves onward to the attracting inagnet, of course carrying with it the
commutator which is attached to its axis. This movement unmag-
netizes the electro-magnet, and magnetizes the next one, and so on.
Now let us turn our attention to the other commutator, which
is fastened to the axis of the cylinder on the right side of the
table. The only difference is that a different obliquity is given
to the arm carrying the commutator, so that, instead of acting
upon the magnet immediately preceding the cylinder, it acts on
the one immediately behind it. But this position, which is behind
the cylinder as it moves in one direction, is of course before it
as it returns the other way; so that, in fact, this second com-
mutator acts in a similar way to the first, urging the cylinder
onward in the direction in which it is going at the time. It is
necessary to recollect that the two commutators do not act at

page_text: the same time, but that the electrodes and the hilex ends, and the
commutator on the left side of the table, which are employed during
one stroke of the engine, are all thrown out of action during the
return stroke, and those on the right side of the table are
then brought into action. The iron cylinder employed should be
of considerable diameter, for example, twelve or fifteen inches, sup-
posing the magnets to be placed at a distance of two or three inches
apart, and the cylinder to be in contact with the poles of one of them;
its surface should not be elevated much more than a quarter of an
inch from the poles of the next magnet, which requires that its dia-
meter should be large. The length of the stroke of the engine depends
on the number of electro-magnets which are placed in a row beneath
the table, and is therefore capable of being augmented ad libitum
as far as convenience may permit.
Having thus described the mechanism, it only remains to explain
that the cylinder, being urged by magnetic power from end to end of
the table, communicates its motion to the crank and fly wheel.
The things claimed as new in this Invention are, the general
construction and arrangement of the engine, more particularly the
node in which the cylinder is urged from end to end of the line of
electro-magnets together with the large size of the cylinder, which
causes its surface to be near the surface of two or three of the
electro-magnets at the same time, and the peculiar construction
of the commutators and other mechanism for changing the direc-
tion of the galvanic currents.
In witness whereof, I, the said William Henry Fox Talbot, have
hereunto set my hand and seal, this Eleventh day of June,
in the year of our Lord One thousand eight hundred and
Witness,
FRED. HARRIS.
W. H. F. TALBOT. (L.S.)