IMPROVEMENTS IN OBTAINING AND APPLYING MOTIVE POWER
Year: 1851

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
JAMES GREENOUGH, now residing in the City of Washington, in the United
States of America, Gentleman, send greeting.
WHEREAS Her present most Excellent Majesty Queen Victoria, by Her
Royal Letters Patent under the Great Seal of Great Britain, bearing date at
Westminster, the Third day of May, in the fourteenth year of Her reign,
did, for Herself, Her heirs and successors, give and grant unto me, the said
John James Greenough, Her especial license, full power, sole privilege and
authority, that I, the said John James Greenough, my exors, admors, and
assigns, and such others as I, the said John James Greenough, my exors,
adñiors, or assigns, should agree with, and no others, from time to time and
at all times during the terms of years therein mentioned, should and lawfully
might make, use, exercise, and vend, with England, Wales, the Town of
Berwick-upon-Tweed, and in all Her Majesty's Colonies and Plantations
abroad, and in the Islands of Jersey, Guernsey, Alderney, Sark, and Man,
an Invention of "IMPROVEMENTS IN OBTAINING AND APPLYING MOTIVE POWER,"
being a communication from abroad; in which said Letters Patent is con-
tained a proviso obliging me, the said John James Greenough, by an instru-
ment in writing under my hand and seal, particularly to describe and ascertain
the nature of the said Invention, and in what manner the same is to be
performed, and to cause the same to be inrolled in Her Majesty's High Court -
of Chancery within six calendar months next and immediately after the date
of the said in part recited Letters Patent, as in and by the same, reference
being thereto had, will more fully and at large appear.

page_text: NOW KNOW YE, that in compliance with the said proviso, I, the said
John James Greenough, do hereby declare that the nature of the said In-
vention, and the manner in which the same is to be performed, is particularly
described and ascertained in and by the following description thereof (refe-
rence being had to the Drawings hereunto annexed, and to the letters and
figures marked thereon (that is to say) :-
This Invention consists in certain modes of obtaining a motive power from
the mutual action of magnets and conductors conveying currents of electricity.
The power thus obtained I denominate the electro-dynamic axial power, to dis-
tinguish it from the electro-magnetic power hitherto obtained from the mutual
action of magnets. The elementary principle upon which my Invention is
founded is, the axial force by which a helix conveying an electric current
draws a magnet within it in the line of its axis, and reciprocally the magnet
draws the helix in the opposite direction. The electro-dynamic axial
power is
intended as a substitute for steam and other motive power in engines of
reciprocating, vibrating, or rotary movements, and is also applicable with the
utmost simplicity of construction to the operations of pile driving, crushing,
breaking, stamping, pressing, punching, beating gold and other metallic leaves,
trip hammers, and pumping, to which operations the magnet or axial bar
may be applied directly without the intervention of other machinery, for the
axial bar may be lifted through a series of coils and suffered to fall by its
own weight, or having been lifted, the power of the helices may be added to
accelerate its fall; and in the case of pumping, the axial bar acts as the
piston and the helix as the cylinder, as herein-after described. This principle
of the axial force has long been known as a matter of scientific interest, but
from the fact that the forces thus called into action have appeared to be far
inferior to the statical power of electro magnets, they have not been deemed
available for mechanical purposes. But I have discovered means of rendering
the axial forces dynamically superior to those of the electro magnets, and
have, morcover, found that difficulties incident to the employment of electro
magnets, and seemingly insuperable, do not exist in my modes of using the
axial force, which present advantages, numerous and great, beyond all other
electro-mechanical devices. They may be enumerated as follows:-The
helices and magnets may be increased to any size, so far as has yet been
tried, with proportional dynamic effect, while the reverse of this is true with
electro magnets. The larger the magnets the greater the loss of dynamic
power. This is owing to the great length of. timo required to charge and
discharge magnets, especially when their polarities are to be reversed. The
slow developement of power in electro magnets, and the retention of power

page_text: when developed, are due to certain resistances in the mass of iron and the
action of induced currents. The larger the mass the greater these difficulties,
and if the attempt be made to obviate them by the employment of a great
number of small magnets, other and equally fatal; difficulties arise; they
need not be now enumerated, but the most obvious are great complication
and expence, and although the resistances due to the mass may be diminished,
yet the adverse action of induced currents still continues. The induced
currents, known as the initial secondary current and terminal secondary
current, are both unfavorable in electro-magnetic engines, while in my modes
of exhibiting the axial forces the adverse action of the initial secondary is.
much diminished, and the action of the terminal secondary, which is by far
the stronger of the two, is turned to a favorable account. The retention of
magnetism also I have found is not only not unfavorable in the axial
machines, but, on the contrary, I have invented means of retaining the
magnetism to its fullest extent as one of the most important elements of
improvement. In electro-magnetic engines the power is made up of a series of
impulses, acting with a varying force through short spaces; for the reason that
the action of magnets is feeble except when they are in close proximity, their
power varying nearly as the cube of the distance. In my mode of operating
the axial force it is continuous and uniform for any extent of motion desired,
both very important mechanical advantages. In connexion with this Invention
I have discovered that it requires an appreciable time to charge and discharge
a helix, or, in other words, that a considerable time, even a full second in some
cases, elapses before the current rises to its maximum in a helix, and about.
the same time before it falls; also that this time becomes greater when an
iron bar is inclosed within the helix. The importance of this fact as an
eleinent in the operation of all electro-mechanical contrivances has never been
before recognized, and I have, by my improvements, to, a great extent, overcome
the difficulties it involves. The helices are so arranged that a large portion of the
electric current is retained nearly at its maximum nearly all the time, while, at
the same time, the inclosed bar is made to retain nearly all its magnetic force
nearly all the time. Great advantages are thus secured. The employment
of a great number of small helices gives facility in the construction and
bandling of the helices, for it would be impracticable to handle one entire
helix of full size for a large engine without risk to the helix. Another advan-
tage is in the insulation. If a defect occurs in one small helix its influence.
extends to only a small portion of wire, while in a large helix it would extend.
to a long portion. Moreover, if there should be no direct defect in the con-
struction of a helix, yet the tendency of the current to pass across from one:

page_text: layer of wire to the layer above or below, it is great in proportion to the extent
of the layer; and hence, in large helices, a thicker insulating material would
be required at the expence of power, as it would separate the wires to a
greater distance. In the employment of large helices the sparks from the
terminal secondary currents are very intense, and consume the metallic points
of contact with great rapidity. This evil is much diminished by the use of
small helices, more especially in the peculiar manner herein-after described.
The employment of a number of small helices also gives us the capability of
trying experimentally a variety of modes of action. For instance, if a number
of small helices are connected together so as to act as one large helix, the
current may be first let on to the whole range constituting one helix, and then
dropped off from one helix after another as the axial bar moves through them;
and thus, there being no new helix to charge, there would be no initial
secondary to encounter. I have discovered that each time the current is let
down from a long helix to a shorter one, a new and strong impulse is made
upon the bar, exceeding the power of the long helix upon the bar. Or, in
case of a long stroke in the engine, some one or more of the helices may be
charged considerably in advance of the moving bar, while also a suitable
number of the helices about the ond of the bar are charged. This would
allow the advance helix or helices to arrive at their maximum charge before
the bar reaches them, even if the bar is moving at considerable velocity. Or
the currenty ma commence in a small number of the helices, and sa the bar
advances we may go on introducing helix after helix successively until the
whole series is included in the circuit. But the most important mode of
exhibiting the action and advantage of the small helices is that soon to be
described, in which the current is conveyed through a given number or series
of helices, and as the bar moves along the current is withdrawn from the rear
helix of the series, and thrown on to a helix in advance of the series. Under
this operation, if the current has attained its maximum in the series of helices,
it falls from its maximum only in the rear helix, and has to rise to the same
degree only in the advance helix. If the bar had to move through one long
entire helix the force exerted upon it would increase up to a certain point,
and then diminish from this point. The point of greatest action varies with
the dimensions of the helix and the bar, but ordinarily this point is reached
when the end of the bar is about two thirds through the helix. The dynamic
maximum differs from the statical maximum; that is, when the bar is in
inotion the point of greatest action is not where it is when the bar is at rest.
Now it is evident, that if the end of the bar while in motion could always be
in or near the point of greatest action, it would be operated upon with nearly

page_text: a uniform, continuous, and maximum force; that is, the effect would be
similar if we should suppose the helix should be pulled or forced along as
fast as, and in the same direction with, the moving bar. My mode of
charging the helices attains this desirable result. For instance, suppose we
have a series or range of helices occupying three feet longitudinally, and
we wish to operate upon the bar with six of the helices, each of which
occupies two inches longitudinally. When the end of the bar has advanced
two inches towards the maximum, the current is withdrawn or cut off from the
rear helix of the series, and conveyed to one in advance, and thus we have
still six helices in actual operation. This number or series, whether it consist
of two, three, four, five, six, or any other number, I denominate the helix of
actual operation. The current in this case falls in one helix, rises in one, and
is sustained in five, and the operation is more perfect in this respect the
smaller the individual helices compared with the helix of actual operation.
By this contrivance the force operating upon the bar is nearly uniform and
near its maximum. The spark from the secondary current, from the discharge
of small individual helices, is so slight that the metal of the cut-off (hereafter
to be described) is but little burned. In a reciprocating engine the current
must be cut off at each end of the stroke from the whole helix of actual opera-
tion, and this occasions a large spark at these two points; but these are of
comparatively little consequence, as their ill-effects can be guarded against.
In the rotary form of the axial engine but one of these sparks will occur in a
revolution. The principle of operating upon an axial bar by a succession of
small helices is equally applicable to rectilinear reciprocating engines, curvi-
linear, reciprocating, or vibrating or pendulum engines, and rotary engines;
but to the rotary engines it applies with peculiar advantages, for reasons
shortly to be explained. In all cases it requires time to charge a magnet to
its full power; hence, if, in a reciprocating or vibrating axial engine, the mag-
netism of the bar should be suffered to fall at the end of the stroke, a loss of
time or power would follow, and hence it becomes important to sustain the
magnetism of the bar to its full extent. In the rotary engine this is accom-
plished in the simplest manner. In the reciprocating engines I effect this in
several ways. First, a helix is attached to the moving bar or bars in any of
the several modes herein-after shown, and second, two sets or ranges of
helices may be so arranged as to operate upon opposite ends of the same bar,
and just before the current ceases to act upon one end it commences to
operate upon the other end, and thus the bar is always kept in a magnetized
condition. As the greatest magnetic power is always at the operative end of
the axial bar or magnet, the transition of magnetism or the magnetic condition

page_text: from one end of the bar to the other is attended with some loss, though slight.
The first-named plan of sustaining the magnetism of the bar may be combined
with this latter. When the attached helix is used, it may be charged by the
current permanently, or it may be charged only at such intervals as may be
most needed. The attached helix may also be used in the rotary engine,
although there is not the same necessity for it as in the reciprocating engines.
In the rotary engines, as the same end of the axial bar is always operative
and always charged, it follows that the condition of a permanent magnetic
charge in the bar is most fully answered. The attached helix, however, may
be used with the rotary engine, if it should be deemed necessary, although it
would be attended with considerable inconvenience. The attached helix may
be charged with an independent and appropriate battery, or it may be charged
by the same battery with the engine. One of the principal improvements I
have made in this application of power consists in the employment of square
or rectangular wires in the construction of helices. The great advantage of
such form of wire over the round wire usually employed for this purpose may
be mathematically demonstrated. I am aware that flat spirals, as they are
termed, have been made of copper ribbon; but such spirals are distinct from
helices or heliacal coils. The helix is made by winding the wire longitudinally
in the direction of the axis of the magnet and back, and forth upon itself, until
completed, or, explicitly, the helix is made like a screw thread, while the spiral
is in the form of a volute. The most perfect form of the wire for economy of
magnetic power is the square; and as in my mode of applying the insulating
material to the wire it is only necessary to cover two sides of the wire, it is
evident that, as the square form is that which exposes the least surface, it
requires the least amount of insulating material. As in the employment of
round wire a great deal of interstitial space is left not filled by the wire, and
as the power of the helix is in the direct ratio of the distance of its mass from
the axial bar, the advantage of the square wire is at once obvious, for it fills
the entire space, and brings the greatest possible amount of conducting mate-
rial in proximity to the axial bar. There is one instance, however, in which I
have found an advantage in the use of flat spirals for the special purpose of
axial engines, viz., where the individual helices are to be made so small or
narrow as that a single strip of flat copper wire or ribbon, the entire width
of the helix, will furnish the required conducting power. In this case the flat
spiral may be substituted for the wire helix, with economy, in the following
particulars the flat spiral is easy of construction, and there is less loss of
space on its sides. This latter is an important consideration in the axial
engine where the entire helix or range of helices, being composed of a

page_text: great number of small. helices, would be subject to a considerable loss from
the vacant spaces on the ends or contiguous faces of the individual helices.
In every helix, whether of round or square wire, there are upon its end faces
vacant spaces for each superposed layer of wire. These spaces occur from
the fact that where the wire commences to return upon itself, it must rise
over the last completed layer by one thickness of wire. In the wire helix I
amend this defect by the introduction of what I term the risers. These are
portions of copper wire made wedge shape and curved to fit the empty spaces
into which they are inserted while the helix is being made or wound up and
the upper surface of the riser is in metallic contact with the lower surface of the
over-riding wire, and thus the entire space is filled up with conducting material.
Another important part of this Invention is the cut-off. This is the
device by which the current is conveyed to the helices, and withdrawn or cut
off from them at the proper times. The wires of the helices are connected.
with segments of metal in a manner herein-after described, and metallic
springs, termed communicators, press upon these segments, the metallic
springs being respectively in electric connexion with the poles of the battery:
by means shortly to be described. In electro-magnetic engines, both rotary
and reciprocating, it has been usual to employ a rotary cut-off or pole changer
attached either to the main revolving shaft or to the fly-wheel shaft. This.
necessarily involves an unsightly and awkward plexus of conducting wires, and
a considerable amount of wire not in operative use, and also. other practical
difficulties. These I entirely overcome by the use of a sliding or reciprocating:
cut-off for reciprocating axial engines. The segments of the cut-off are
arranged in line near to and parallel with the axis of the helices, and extend
about the entire length of the range of helices. This gives great facility in
the construction, repair, and accurate division of the cut-off, renders it very
accessible in every part, and very much shortens the conducting communica-
tions between the segments of the cut-off and the helices. As the edges of
the
segments are burned off by the current and secondary sparks, the accurate
working of the engine is in time interfered with. To remedy this difficulty I
have invented the following improvements:Where the segments can be made
of a square or circular forin, I arrange for turning them around occasionally,
so as to present new and clean edges. I make also a similar provision for
the tips of the communicators that are in contact with the segments. Where
the segments cannot be turned around conveniently, I face their edges with
shifting pieces of metal termed shoes. As these shoes are burned on their
edges, they are slid along so as to present new edges. The shoes may be
made of any of the precious or least oxidizable metals.

page_text: Another improvement in the employment of the axial forces consists in
combining the repulsive power of the axial bar with the axial force. I have
discovered that when a bar of iron, either solid or hollow, is inserted in a
hollow axial bar, it is in certain positions repelled out of the hollow axial bar
with great force. This is important in an electro-mechanical point of view, as
I shall directly explain. If the hollow axial bar or tube, inclosing another
bar, be inserted part way within the helix, the hollow exterior and the interior
or inclosed bar, being in the same magnetic condition, mutual repulsion will
ensue; and if the exterior bar be fixed, the interior will be driven out and
through the helix, the axial force of the helix acting in conjunction with the
repulsive force. It is evident also that the attractive forces of the exterior
and interior bars may be employed; but it is for a special purpose that this
combination of axial and repulsive forces appears valuable, as will shortly be
described. For use simply as a motive power, it involves, to some extent, a
difficulty already mentioned as inherent in electro-magnetic engines, viz., loss
of time or retardation from the retentive power of masses of iron. An
important application of the axial engine is for purposes of pumping either
air or water. All pumps hitherto known must be operated by being geared
to some propelling engine; but in the axial pump the propelling parts of the
engine are the essential parts of the pump, viz., the helix forms the cylin-
der of the pump, and the axial bar the piston, the induction and eduction
valves being arranged in any of the modes common to pumps. The helix or
range of helices is to be lined with a brass tube, and the end of the axial bar
packed as usual for pistons. In some cases where powerful batteries are
employed, the helix is heated to some extent; but in the pump the circulation
of air or water will reduce the temperature sufficiently to prevent any unfavor-
able expansion of the parts. As in navigation and locomotion the steam
whistle is now generally used for a signal, I contemplate the employment of
the axial pump to operate the whistle by means of air in place of steam.
It is for the axial pump that the axial repulsion may be employed with some
advantage, for the exterior hollow bar may serve as the pump cylinder, and the
interior bar as the pump piston. If a thick brass lining for the helices should
be used, it would bring the axial bar too remote from the helices; but the
repulsion tube of iron serves as a medium of transmitting magnetic power to the
enclosed bar or piston. In the different forms of engines of the reciprocating
and the vibrating or pendulum kinds, the general features or modes of
mounting, taking off power, and reversing motion, will be found similar to
those employed in steam and other motive engines, and may be varied to suit
the taste of the engineer, or peculiar duties required. The rotary axial engine,

page_text: however, is peculiar, and differs essentially from all other motive engines.
The axial bars are bent into the circular form, and any number of axial bars
may be introduced into the ring or circle. If one bar only is used;-it may
form a considerable portion of the ring, but the remaining portion must be of
brass, or other non-magnetic material. The length of the brass, or the space
between the two ends or poles of the axial bar, must be such that one will not
disguise each other's action; an operation well understood by magneticians. If
two or more axial bars are used in the same ring, just as many segments or divi-
sions of brass must be used, and the same rule for distance observed. This ring
cannot be connected by arms or spokes to a central shaft, and must, therefore,
rest and run upon anti-friction rollers. Three rollers may be sufficient, and they
may be inside or outside of the ring, for the purpose of communicating motion to
a driving pinion; and this pinion may serve the double purpose of a driver and
anti-friction wheel. In case a very heavy ring is used, the power may be
communicated from the anti-friction wheels themselves. The ring may be
round, square, or flat, or ovoid, and instead of cut gearing, a groove may
be cut in the ring to receive a belt or band for driving machinery. If a belt
is used, the cut-off may be worked by a small gearing. cut in the ring, or by
cam-shaped surfaces in a small groove in the ring. If, however, a chain band
is used on the ring, a cut-off with positive motion may be worked by the band.
Guide rollers must also in all cases be used on the sides of the ring, to'keep it
steadily in its position. The ring must be made to take apart in order to put
on the helices. If the curvature of the ring is large, the small or individual
helices may be made upon a straight mandril like those for straight bars, the
curvature differing so little from a straight line in the space of one to two'
inches, when a ring above four feet is employed, as to be of no practical
importance. The helices must be firmly fixed in suitable framework. If the
helices could be continued in one entire ring, the operation of the engine
would be perfect; but as considerable spaces must be left for the supporting
rollers and gears or bands, the helices must there be interrupted, and the
cut-off would also become irregular and intense; secondary sparks would
occur at each break. I have obviated this difficulty by the following con-
trivance: On each side of the anti-friction rollers I introduce extra helices
surrounding the regular helices, and just so many as would be required to fill
up the vacant space. These are divided equally; there being the same number
on each side of the rollers. These render the action of the cut-off regular and
continuous, and the mode of connecting them will be hereafter shown. One
break is necessary, and consequently one intense spark is necessary in the
range or circle of helices; for if the whole circle of helices were unbroken, the

page_text: current would divide and run in both directions aroung the ring, with counter-
acting influences.
Another improvement consists in constructing the helices of wires of different
sizes, increasing in size and conducting power from within outwards, thus
equalising the resistances in the different portions of the helices. The Drawing
represents diagrams of the various parts required to form an engine of all the
different types, and these can be variously changed to suit the requirements of
the engineer. Figure 1 is the representation of the details of a helix of wire,
sections of various shapes of wire being shown at 1, 2, 3. (a) is a section of
square wire covered on two sides with any non-conductor (6) suitable for the
purpose; strips of thin cotton cloth I have found to answer. The wire thus
covered is wound on to a mandril or bar of metal, first covered with the
insulating material. The cross section of this mandril should be round, or of
any other figure corresponding with that of the axial bar to be used in the
engine, and of a little larger size, so that the bar can move easily in the helix
when in operation. The wire is wound on to the mandril in layers compactly,
so as to form a helix of the proper size for the purpose intended. At the
termination of each layer there is a space where the wire is made to double
over it for the next layer, and this space can be filled with a piece of the same.
metal, formed to fit the space. One of these is shown at c, c', Figure 2, detached
from the helix, and ready to be inserted. This piece of metal I term a riser..
It answers two important purposes: first, in making the helix, it prevents the
edges of the wires where they cross from cutting through the non-conductor,
and thus forming an improper connection; and secondly, it adds to the amount
of metal in a. given space. The helices are represented in Figure 3 in a
connected series as prepared for use. P, N, are two long bars or strips of
copper in connexion respectively with the positive and negative poles of a
galvanic battery. A, B, C, D, E, are five of the individual helices in the series.
The end y of helix A, is connected. by strips of copper, z, with the end ¹ of
helix B, the end y' of helix B with the end of helix C, and so on throughout
the series. The first end of helix A is connected with a strip or segment of
copper, and the other end of helix A is connected with a segment y. The
first; end of helix B is connected with a segment a¹, and this segment is also
in connexion, with y of helix A, by means of the strip 2. The endy of helix
B. is connected with :a of helix C, and so on throughout the series..." Two
strips of metal, m", m", termed the communicators, are shown respectively.
in contact with x of helix A, and y' of helix D, and also in connexion,
respectively with the poles of the battery through the bars P, N. If now the
communicators be shifted along the distance of one segment, they will come in.

page_text: contact respectively with segments x and y"" The helix A will be cut off or
left out of the series, and the belix E will be taken in or included. Before
shifting the communicators, there were four helices, viz., A, B, C, D,. in the
circuit, and after shifting there are four helices included, viz., B, C, D, E.
This operation of excluding and including the individual helices, and retaining
a given number at all times in the circuit, continues throughout the whole
series of helices. The included number of helices constitute what I term the helix
of actual operation. If, now, we suppose a bar of iron inserted through A, B, C,
up as far as the first end of D, it will be drawn with great force towards the
other end of D. If the communicators move along with the iron bar, the
helix E will next be included in the circuit, and helix A excluded, the iron bar
being ready to enter and move through E with the same force as it moved
through D, and as it moves through the short space of one individual helix
under the influence of the helix of actual operation, it will move throughout
the whole series with nearly a uniform power. It is important that the
individual helices should be narrow or short compared with the helix of actual
operation, and they are so represented in Figure 5. The communicators may
be attached to the moving bars of iron by means of sliding cross heads, or
worked by connecting rods and cranks or excentrics on the shaft of the pro-.
pelling engine. Figure 4 is a plan of the diagram, showing the segments
above the helices, and for convenience brought into closer proximity. Figure 6-
is the axial bar of iron; which may be of iron or steel, but I have found soft.
iron to answer best. It may be of any form in its cross section, and of almost
any length convenient; provided always, that it should be as long, or longer,
than the helix of actual operation. It may be hollow or solid; but for large
sizes hollow bars answer best. The axial bar is attached by a connecting rod
to the crank of a fly-wheel shaft, after the usual manner of steam and other
engines, and the bar may be guided by cross heads, or upon a rod running
through its axis, or suitable guides within it, or it may run in a thin brass
tube lining the helices. The arrangement of the segments, communicators, and
bars for battery connexions constitute together what is termed the cut-off, the
most approved form of which is seen in Figures 7, 8, 9, 10: The cut off may
be of rotary form, and worked directly around the fly-wheel shaft; but I
prefer the straight and reciprocating form for reasons before given. Generally
speaking, the principles and details for working steam-engine valves will serve
as guides for the mechanical working of the cut-off. The segments in Figures;
7 and 8 are represented as in a line with each other, and the communicators
run back and forth on this line. a, a, a', a', are the segments connected.
respectively with the helices upon the principles laid down in the illustration of

page_text: Figure 3. The communicators b, b, b', b¹, are stout copper springs attached to
the sliding metallic heads c, c, which aro firmly fixed to the carriages of baked
bard wood d, d. The sliding heads run upon the metallic bars or ways e, e¹, e².
The communicators press firmly upon the segments, and their elasticity
causes the sliding heads to bear up against the ways, and insure good metallic
contact. On one side of each of the carriages there is a lateral spring ff, to
insure pressure upon the ways laterally and steady the carriages. One of the
ways e, is in permanent connexion with one pole of the battery, and the other
two, c', e, are alternately brought into connexion with the other pole of the
battery by means of the reciprocating carrier 9. The carrier g is in permanent
connexion with this pole of the battery, and is worked back and forth by the
arm h. This arm h is pressed against a cam on the fly-wheel shaft by a
helical spring; and the cam is of such form and position that it shall move the
arm and shift the carrier once for cach half revolution of the shaft. As the
shifting or change must be somewhat abrupt, the end of the arm pressing against
the cam is provided with a steel friction roller to render the motions casy and
smooth. To reverse the motion of the engine, the arm his moved to one side or
the other of the centre of the carrier, and the pins j, j, on the carrier fall into
the slots on the arm, according to its movements, and thus reverse the order in
which the galvanic current is conveyed to the separate ways e', c³. Figure 7 is a
plan of the cut-off; Figure 8 an elevation of the same, shewing the attachment
of the carriages and communicators to the guide rods of the axial bar.
Figure 9 exhibits the carrier and working arm, and Figure 10 is an end
view of the cut-off and helices. The most simple form of the reciprocating
engine is seen in Figures 11 and 12, where a simple straight axial bar is to
bo moved back and forth through two series of helices k, k. These helices
are to be arranged and connected, in the manner just described, with each
other and with the segments of the cut-off. The cut-off, as represented in
Figures 7, 8, 9, 10, is designed for an engine of this description. The cut-off
is secured firmly to the framework holding tho helices, and runs parallel with
the line or series of helices. I have before explained the importance of
constantly sustaining the magnetism of the axial bar, and this form of engine
has an advantago in this respect. The auxiliary helix L, L, Figure 14,
attached to and moving with the bar, and charged by the battery permanently
or at proper intervals, is employed for this purpose, but although it may be
used with the single straight axial bar, it is not necessary as in other forms.
Figure 12 shows a more compact arrangement than Figure 11. Figures 13
and 16 exhibit a multiplication of the single axial bars. Figures 14 and 15
show the compound or U-form bars, in which there is an advantage in

page_text: bringing the two poles of the magnet into proximity, but a necessary loss
from being obliged to use an auxiliary helix L to sustain the magnetism:
Figures 17, 18, 21, 22, represent another series of modifications of the axial
engine, in which the principles of 11, 12, 13, 14, 15, are preserved, except
that the curvilinear motion requires a well understood mechanical difference
in the modes of mounting the engine, taking off power, etc. These are called
pendulum engines.. Figure 20 exhibits the rotary engine. An entire.ring,
composed of brass and iron segments, is mounted upon friction rollers; and
arranged to revolve continuously in the series of helices C. The mode of
connecting the helices with each other and with the segments of the cut-off,
is the same as that described for the reciprocating engine, except that the
motion of the communicators is rotary. The wires are carried to the cut-
off K, which is composed of segments attached to a wooden circle, and the
communicators are driven by the shaft, wherever it may be, which takes its
motion from the axial ring. The power of the axial ring I have communi-
cated hitherto by sunk gearing in the: ring to a pinion in contact with its
periphery, but it is obvious that a band may be used, or a chain band, or the
power may be communicated by friction. But in all cases a positive motion
is required to work the cut-off, and this may be done by a small and special
gear cut in the ring, or by cams, or a cam-shaped groove in the ring. Where
the introduction of the friction rollers causes a break in the continuity of the
helices and the cut-off I introduce extra helices a, a, a, a, outside of the regular
series, and as close to the empty spaces as possible; an equal number on each
side of the spaces, and just so many as would be required to fill up the empty
space; and there are to be charged in proper order consecutively with the
regular helices, and thus the cut-off is filled up, and the action on the axial
bar unbroken. Friction rollers are to be used on the sides of the axial-ring to
keep the ring steadily on its bearings and from striking the helices. Where
the communicators pass from one segment of the cut-off to another, and
where, in fact, any break in the current occurs, a bright spark is produced
which consumes the metal and interferes with the accuracy of the cut-off, and
impairs the working of the engine. To remedy this I place extra pieces a³¹, y¹,
Figure 19, of copper or other metal difficult of oxidation. on the edges of the
segments, and these pieces, being firmly in contact with the segments to insure
conduction, receive the action of the spark. These pieces, termed shoes, are
capable of being moved along as they become injured, to present clean edges,
and are after a while replaced by new pieces.
I have also made important improvements in the galvanic battery of the
species known as Grove's battery. The platinum plate is often clamped

page_text: by screws to the zinc plate, which has many objections. It is also soldered
sometimes to the zinc plates, which is also objectionable, for when the zine
plate is worn out it is difficult to separate the platinum from it and clean
it for attachment to a new plate without waste of the platinum. Figure 29
shows my mode of attaching the platinum to the zinc. A narrow slit, about
one quarter inch deep, is sawed in the edge of the zinc plate, and the
platinum inserted into this slit, when its edges are brought powerfully
together by hammering or pressure, and firmly secures the platinum. One
edge or lip of the slit projects a little way beyond the other, so that when
it is desired to take the platinum out the slit may be easily opened. The
edges of the slit are covered with some varnish.
Another improvement in this kind of battery consists in substituting for the
platinum a carbon plate of peculiar preparation. The difficulty in using carbon
plates hitherto has been that of making a good and durable connexion with the
zinc or positive plate of the battery. This I effect in the following manner :-
I place sheet-iron plates in the retorts of gas works, taking care to cover one
edge of the iron plate with clay to the distance of one quarter to half an inch.
The carbon of the retorts will deposit in a chrystalline form on the iron plates
and completely envelope them except. where they are covered with clay.
This carbon serves well as a negative plate, and the uncovered edge admits
of a soldered or good mechanical joint, like that just mentioned, with the
zinc plate.
Another and most important improvement in this battery is represented
in Figure 26. The interior or porous cell for the nitric acid is made
together with the outside cell, so that the nitric acid may be drawn off by the
stopcock a, and the sulphuric acid by the stopcock b. Both cells are
manufactured of porous earthenware, and left unglazed. The outside cell is
then dipped into hot varnish, or oil, or any bituminous or resinous matter,
and its pores: filled up, leaving the inside cell porous. All glazed ware is apt
to be injured by acids, and I have found it a great improvement in many
respects to omit the glazing, and thus saturate them. The form of the zinc
plate for this battery is shown at d. This is a great saving, for it requires.no
more zinc. than is in actual use in the battery. The form of the platinum.or
negative plate is seen at e. The platinum is made to envelope entirely a stout
copper wire g and soldered to it, or the copper wire is drawn with a platinum
casing and the platinum plate welded to it. The protected copper wire of one
cell is inserted into the glass tube h of, the next adjoining-cell, and a small
quantity of mercury is kept in this cell, which mercury makes contact with
the zinc plate of that cell, and also with the lower end of the protected wire

page_text: within the glass tube. Ordinarily in Grove's battery one plate or one cell
cannot be taken out from the middle of the series without disturbing all the
rest; but in this battery it will be seen that either a zinc or platinum
plate, or a cell, can be removed at once without disturbing any other. As
there is a shallow stratum of mercury kept in the bottom of the zinc cell, the
plate may be re-amalgamated any time by merely turning it upside down, for
the quantity of mercury adhering to the bottom of the plate will gravitate and
spread downwards upon the zinc plate; the plates will also wear evenly.
This battery takes less time to charge it and discharge it than any other; it
requires less zinc and less platinum, and may be cleaned, repaired, and kept
in regular action better than any other. Another very important.advantage is
this, it admits of greater proximity between the positive and negative plates
than all other forms, while at the same time there is a plentiful supply of both
acids. The porous cell need not be above one quarter of an inch in width,
the chamber k holding a supply of acid sufficient to keep up a prolonged
action.
Figure 23 is a modification of Figure 21; and Figure 24 a modification
of Figure 22. Figure 27 shows a mode of applying the reciprocating axial
bar to a double-acting pump, the principles of which have been before
explained. Figure 28 shows a mode of applying the repulsive axial forces.
a, a, are two bars of soft iron working back and forth in the iron tubes b, b,
surrounded by the helices c, c. The repulsive action of the tubes is here
alone employed, but by elongating the repulsion tube and inserting it half or
quarter way into the helices, the bars a, a, being also as long as the repulsive
tubes, and inserted entirely. within them, it is evident that the axial force of
the helices will co-operate with the repulsion of the tube. The repulsive tube
is to be lined with brass. Figure 25 exhibits several modes of applying the
auxiliary helices to the axial, bar, these bars, with their helices attached;
moving through the helices as in other cases descitband serving to keep
the magnetism of the bars.
up
What I claim as of my Invention is,―
First, the employment of a succession of helices in line, through which the
axial bar or bars are to be drawn or forced, whether the helices be arranged
in a straight line to operate on a straight bar, or in a curved line to operate,
upon a curved bar, whereby any desired length of stroke may be obtained;
or a continuous rotation maintained, and an equable action kept up either
upon the straight or curved axial bars, for the purpose of obtaining a motive
power.

page_text: I claim, second, generally the employment of square, flat, or rectangular
wires of any known form in the construction of an electro-magnet helix when
such wires are wound helically back and forth. I am aware that copper ribbons
have been wound up spirally, that is, to form flat spirals, and this I do not
claim in itself, but I limit my claim to the use of such wires when wound
helically and continuously back and forth and over and over until the whole
helix is finished; and I claim specially the employment of square, flat, rec-
tangular wires or ribbons of any proportion or dimensions, in the construction
of helices or spirals when applied to operate the axial bars for the purpose
of obtaining a motive power. I claim such wires for this special purpose, as I
have discovered peculiar advantages in their use in this particular connection
or combination.
I claim, third, the peculiar mode of operating with a succession of helices,
as described, by which I ensure a uniform action upon the axial bar or bars
throughout the whole length of tho stroke or its continuous rotary motion,
and prevent, in a great measure, the injurious action of secondary currents,
and also preserve the metal of the cut-off in a great degree from being
burned by the spark at breaking the connection, said mode consisting chiefly
in employing a number of sections or short helices in a line, and using
several of these at a time to operate upon the axial bars, which several
sections form what I term "the helix of actual operation," and as the axial
bar advances, sections are cut off from one end of the circuit, and others
added to the helix of actual operation. In other words, it may be stated
thus, the helix of actual operation is a certain portion of a long helix made up
of a number of short helices or sections, which helix of actual operation pre-
serves a constant relation to the position of the extremity of the axial bar
throughout its motion, and this secures uniformity of action and the other
advantages named.
I claim, fourth, the mode of effecting this peculiar action of the helix of
actual operation, said mode consisting in the manner of connecting the short
helices with each other and with the portions of the cut-off, and bringing these
last in communication with the poles of the galvanic battery; that is to say, all
the elementary helices are connected together, and also with the appropriate
segments of the cut-off, while the current is conveyed to the helices by
means of the communicating slides which are connected with the poles of the
battery, all according to the manner fully set forth in the descriptions and
Drawings.
I claim, fifth, the employment of the additional or outside helices in the

page_text: rotary axial engine, said helices being to compensate for the loss of space by
the friction rollers, in the manner described.
I claim, sixth, a reciprocating cut-off in combination with the reciprocating
axial movement, for the purpose herein stated. There are many ways obvious
for effecting this, but I claim the reciprocating cut-off in this combination
irrespective of any particular method. Note. It is obvious that many
incchanical devices or principles belonging to other machines, operated by
steam and other forces, will apply to this for moving the parts that direct
the current of electricity, as they direct the current of steam. These devices
are common, and well known to any practical engineer competent to con-
struct machinery; these I do not therefore claim, but I intend only to secure
the advantages in their employment with the axial engine in this special
operation.
I claim, seventh, the employment of hollow iron bars in the axial engine.
Their advantage is as follows: first, they are lighter, and give more power in
proportion to their weight; and further, they will admit guides within them if
necessary.
I claim, eighth, the employment for the electro-dynamic axial engine
of vibrating or reciprocating iron bar or bars, curved or straight, with two sets
of helices for each bar, operating alternately upon cach end of the bar, for the
purpose of keeping up the magnetism.
I claimi, ninth, the manner herein set forth of constructing helices for tho
mechanical application of of electro-magnetic power, that is to say, enlarging
the size or conducting power of the wire from within outward. The enlarge-
ment may be gradual or irregular, but I claim the employment of a larger
wire enclosing a smaller on; in other words, an increase of the size or
conducting power of the wire from within outwards, in any proportion or ratio
found available for this purpose.
I claim, tenth, facing the points of the cut-off, which are exposed to bo
burned by the spark, with strips of metal, which are capable of being turned
around or slid along, so as to renew and expose a fresh surface to the spark.
I claim, eleventh, the mode of insulating the squaro or rectangular wire for the
helices, by means of strips of cloth or other suitable non-conducting material
applied longitudinally, attached to two or more contiguous sides of such wire,
the insulating material being applied to the wire by some adhesive substance,
thereby facilitating the operation of covering the wire, saving material, and
especially making the helices more compact.
I claim, twelfth, the employment of a helix or helices attached permanently

page_text: to the axial bar or bars and moving with it, for the purposes of increasing the
electro-dynamic effect, and keeping up the magnetism of the bar or bars.
I claim, thirteenth, the rotary axial engine, substantially as described, irre-
spective of the form of the cross section of the bars, or their number, or the
arrangement and number of the helices, or the modes of gearing, or of the
modes of working the cut-off.
I claim, fourteenth, the pendulum or vibrating axial engine, as in Figures 10
and 11, irrespective of the form and character of the helices or bars.
I claim, fifteenth, the mode of securing the platina to the zinc instead of
soldering. By this I effect a considerable saving of the platina, and great
facility in uniting the two.
I claim, sixteenth, the mode of compensating for the obliquity of the wire on
the ends of the helices, by means of the risers. In consequence of the
obliquity of the wire to the axis of the helix, a considerable vacant space is
left on the ends of the helix at each layer of wire where the wire has to rise
upon itself to commence a new layer. This space I fill up with a piece of
metal termed a riser, which has been described and figured, made to fit the
space, and this is brought into metallic contact with the wire of the helix.
This is readily done by my mode of covering or insulating the wire, as before
described, which, being upon only two contiguous sides of the wire, leaves that
side next the riser in metallic contact with it; thus the riser comes into the
circuit, fills up the vacant space, and adds to the conducting power of the wire.
When helices are made of flat spirals the riser is not necessary, but when a
continuous wire is used, returning upon itself, the riser is important.
I claim, seventeenth, the manner of preparing the carbon plates, as described,
and the employment of such plates in the battery.
I claim, eighteenth, the preparation of outside cells for the battery, by
varnishing or saturating with oil, wax, resinous, bituminous, or insoluble matter,
unglazed and porous earthenware.
I claim, nineteenth, the mode of making the porous cell attached to the out-
side.cell.
;
I claim, twentieth, the manner of connecting the platinum of one cell with
the zinc plate of the next cell, as described.
...I claim, twenty-first, the form of the zinc plates in combination with Grove's
battery.
I claim, twenty-second, the employment of the axial repulsive forces, either
alone or in combination with the axial attractive force for a motive power, as
described.

page_text: I claim, twenty-third, the employment of the helices and axial bars for
pumping water or air, upon the principle herein described.
In witness whereof, I, the said John James Greenough, have hereunto
set my hand and seal, this Fifth day of August, A.D. 1851.