AN IMPROVEMENT OR IMPROVEMENTS IN THE MODE OF PROPELLING SHIPS AND VESSELS ON SEAS, RIVERS, AND CANALS, BY THE AGENCY OF STEAM
Year: 1817

page_text: OLDHAM'S SPECIFICATION.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
OLDHAM, of South Cumberland Street, in the city of Dublin, Esquire, send
greeting.
WHEREAS His most Excellent Majesty King George the Third, did, by
His Letters Patent, under the Great Seal of the United Kingdom of Great
Britain and Ireland, bearing date at Westminster, the Tenth day of October,
in the fifty-seventh year of His reign, give and grant unto me, the said John
Oldham, my exors, adñiors, and assigns, His especial licence, full power, sole
privilege, and authority, that I, the said John Oldham, my exors, adiñors, and
assigns, should and lawfully might, during term of years therein mentioned,
make, use, exercise, and vend, within England, Wales, and the Town of
Berwick-upon-Tweed, my Invention of "AN IMPROVEMENT OR IMPROVEMENTS IN
THE MODE OF PROPELLING SHIPS AND VESSELS ON SEAS, RIVERS, AND CANALS, BY THE
AGENCY OF STEAM;" in which said Letters Patent there is contained a proviso
that if I, the said John Oldham, shall not particularly describe and ascertain the
nature of my said Invention, and in what manner the same is to be per-
formed, by an instrument in writing under my hand and seal, and cause the
same to be inrolled in His Majesty's High Court of Chancery, within six
calendar months next and immediately after the date of the said Letters
Patent, that then the said Letters Patent, and all liberties and advantages
whatsoever thereby granted, shall utterly cease, determine, and become void,.
as in and by the same, relation being thereunto had, may more fully and at
large appear.
NOW KNOW YE, that in compliance with the said proviso, I, the said
John Oldham, do hereby declare that the nature of my said Invention, and the

page_text: manner in which the same is to be performed, are particularly described and
ascertained in and by the Drawings hereunto annexed, and the following de-
scription thereof; (that is to say,)
My aforesaid Invention and improvement consists in the use and application
of certain oars, which oscillate or move with a peculiar progressively increasing
and diminishing power in a pendulous manner in the water, and may be placed
either under the vessel, or in any part of its two sides, or along the whole of
its sides. If a great number of such oars should be used, such oars may be
placed perpendicularly to the beam of the vessel or otherwise, and swing upon
gudeons or centers, and are feathered or turned in the water in a manner and
by means completely different from anything hitherto used, as will more
fully appear from the following description, and reference to the explana-
tory Drawings or Figures hereunto annexed, which represent some of the
methods by which my said Invention may be carried into effect, viz.:--
Fig. 1 represents one of the oars in a seperate and detached state; these
may be made of iron or other sufficiently strong material. The part A, A.
which is to strike the water and operate upon it to move the vessel, is made
broad and flat, having thin edges, so that the detached Figure B will
represent a section of it from A to A; above this flat part, as from C to C, the
shaft or handle of the oar is round or cylindrical, and at certain distances from
cach other, as well as at the extreme end of this shaft, holes marked D are
made quite through to receive a metal pin or cotter, the use of which with the
holes will be hereafter described. An opposite view of this oar, or one looking
upon its thin edge, will be seen in Fig. 2. The same letters in all the Figures
indicate the same parts wherever they occur. In this last Figure, as well as in
Fig. 3, the oar is shewn as it appears when fixed in its place and ready for work.
In the first place, its cylindric shaft passes up through a tube of cast iron E, E,
Figs. 2 and 3, which at the lower part fits it pretty accurately, but so as to
admit of its being drawn up or down, or turned freely within it; and for the
sake of strength, I make these cast iron tubes conical on the outside, or
thicker above than below, as will be seen in the Figures, and I therefore call
them cones. The frustrum or thick part of each cone terminates in a flat
plate, F, F, cast in one piece with it, the form of which is seen in plan at
Fig. 4, and which must be of sufficient strength to support the standards and
wheel work to be presently described, on which account I call this the
foundation plate. From the two opposite sides of these cones, and imme-
diately under these plates, two gudgeons G, G, project, which are the centers
or fulcra upon which the oars are to swing, and by means of which they are
attached to the sides or other part of the ship or vessel by two couplings or

page_text: plummer blocks, one supported on the side of the vessel, and the other on a
bearer of timber or cast iron, as at H, H, in Fig. 4, and which must be firmly
attached to the side of the vessel. I, I, in Figs. 2 and 3, are also pieces cast
upon the sides of such coves E, E, and carrying short gudgeons upon them for
the purpose of attaching connecting rods to them, by which their necessary
swinging motion is to be produced; thus Figs. 2 and 3 represent a manner of
connecting two such oars together on one side of the vessel; and the
same arrangement must of course be made on its other side. In these Figs.
J represents the main shaft of a steam engine, projecting over or through the
side of the vessel K; its crank having a rotatory motion. L, the rod which
connects such crank to the cone of the after oar, Fig. 3; and M, a connecting
rod passing from above the fulcrum or gudgeon G of Fig. 8 to the projection I
of the cone of the fore oar, Fig. 2, which arrangement will of course only bė
necessary when one oar is moving the flat way, while the next is moving the
thin way through the water, to produce a constant succession of impulses and
equal work upon the engine; but should the engine or other power which is
applied to move them be sufficiently great, and equipped with a fly wheel, they
may in that case all move in the same direction as in the common operation of
rowing, though I prefer and recommend the former mode to be adopted. It
is, however, needless here to describe the many methods of moving my afore-
said oars, or connecting them with the power to be used, as this forms no part
of my said Invention, and must be self-evident to every mechanic. And
having so far shewn how my oars are to be attached to the vessel, I shall
now describe how they are turned or feathered in the water so as to produce
their greatest effect when most required, and to pass with their thin edges first
when their power would be detrimental. This is brought about as follows:-
The cylindric shaft of the oar C, C, passes through the interior of the
cone E, E, and also through the same hole continued in the foundation
plate F, F, and immediately above this through a strong metal toothed
spur wheel N, above which it is fixed by means of the before-mentioned
metal pin or cotter O passing through one of the before-mentioned
holes D in the shaft of the oar. This pin is let into a notch in the
projecting fillett p of the wheel N, so that it not only answers the purpose of
keeping the oar at any required height, but also prevent its turning, except
with the wheel N, which lays upon the foundation plate, and its teeth work
into another wheel Q, in the same situation and of the same size and number
of teeth. Qhas a circular hole through its centre fitting upright cylindric
shaft R, which turns freely within it, its lower end running in a step in the
foundation plate, while its upper gudgeons is supported in the iron frame

page_text: work S, S, the legs of which are firmly bolted down to the foundation plate
F, F. This shaft R is furnished with the two cross arms T, T, on the ends of
which are two falling palls V, V, so hung or placed as to be opposite or in
reversed positions to each other; their points rest on the top or upper surface
of the wheel Q, which has two notches formed in it as at q, q, also in opposite
directions and situations to each other, and at such distance from the centre as
to agree with the situations of the points of the palls; consequently if the
shaft R is turned in one direction it will carry the wheel Q with it, but if turned
in the opposite way it will have no effect upon this wheel, but the palls will drop
into the notches at every half revolution. On the upper part of this shaft R,
and immediately beneath its bearing in the framework S, S, is fixed a bevil
cog wheel U geared to work into a curved rack or segment W, W, having
similar teeth, and which is stationary and firmly attached to the side of the
vessel. The dimensions and pitch of the bevil wheel U and its corresponding
rack W,W, must be regulated by the quantity of stroke of osscillation which is to
be given to the oar, so that in each stroke or vibration the bevil wheel may make
half a revolution. This bevil wheel with its framework being placed above
the center G, upon which the oar with its aforementioned appendages turns,
will of course describe an arc of a circle round that center, and by passing
before the stationary rack will be moved half a revolution for each stroke or
vibration of the oar, but in opposite directions, since it never can complete its
revolution. The consequence of this will be that when the shaft R and palls
V, V, are carried half round in one direction, they will lay hold of the notches
9, 9, in the top of the wheel Q, and carry it and consequently the wheel N with
the oar, half way round; but in returning, as the wheel U moves in an oppo-
site direction, the palls will pass over the notches in Q, which will remain
stationary, as well as the oar, which is now supposed to be making its back
stroke through the water, with its thin edge first, and it is retained in this
position by the friction between the foundation plate and the bottom of the
wheel N, which is assisted by the weight of the oar, and may be increased if
necessary by pressing springs, gripes, or looking palletts, or other contrivances.
By this arrangement the oar will make an half revolution upon its own longi-
tudinal axis at every alternate stroke, while in the intermediate ones it will be
stationary in this respect or not revolve at all, and it must be so hung by the
cotter O that in this situation it will always make its back or inactive stroke,
while in the forward or impelling stroke it will begin its half revolution to pro-
duce the feathering at the beginning of its stroke, and will not compleat it or
present its thin edge to the water again until that stroke is completed which
properly is peculiar to my particular Invention. The motion thus obtained, it

page_text: will be observed, is of a compound nature, consisting first of the progressivo
motion of the ship; secondly, of the pendulous motion of the oar on its center
of vibration; and thirdly, its revolving one on its own axis. By this compound
motion the resistance of the oar increases and diminishes from the commence-
ment to the end of each oscillation, and by which it is accommodated to the
peculiar motion and unequal velocity of the oar as conveyed to it by the revo-
lution of the crank, the result of which is that progression is obtained during
the entire effective stroke or oscillation of the oar, which may extend to about
thirty degrees on each side of the perpendicular. The foregoing details aro
given for the more full and perfect understanding and illustration of my Inven-
tion and the manner in which the same is to be performed. But as the parts
thereof for which I claim the sole and exclusive use, privilege, and enjoyment,
consist in the feathering or turning of the oar or oars, which may be placed on
the sides, under, in the center, or at either ends of the vessel, in such manner
that one half revolution of each oar round its own longitudinal axis is gra-
dually made during each alternate stroke or swing, commencing as before stated
at one extremity of each alternate stroke or oscillation, and to be compleated
only when it has arrived at the other, and by means of which an increasing
and diminishing resistance is opposed to the action of the water, whereby pro-
gression is obtained from one end to the other of each oscillation. I do not
mean to confine myself to the single forms or dimensions of the oar, coves,
gudgeons, framework, or wheelwork shewn in the annexed Drawing, or to
the manner of fixing or arranging the same, since this is only one of many
forms in which my said Invention may be made to act, as must be evident to
every mechanic; for instance, it may be obtained by wheel geer only, without
the stationary rack, segment, palls, or locking palletts herein-after described; as
thus upon one end of the axle G, Fig. 5, on which the cone and oar oscillate,
I place the wheel Z; this I call the feathering wheel, and I cause it to turn in
one direction by means of the lying shaft X between the wheel Y upon the
main shaft v, and the wheel itself Z, or by means of spur geer teeth on the
perephery of the feathering wheel and the wheel Y, the motion of the latter
being communicated to the former by an intermediate spur wheel or wheels as
marked by dotted lines. The cone and oar receive the oscillating motion as
before-mentioned, by means of the crank and connecting rod; a bevel wheel W
is made fast upon the top of the oar shaft to work in the wheel Z. The
dimensions of these wheels will be best expressed in numbers. Suppose the
wheel Y to have any convenient number of teeth (say twenty), the wheel Z
will then require sixty and the wheel W forty, the crank on the main shaft
causing the oar to move two and fro sixty degrees or the sixth part of a

page_text: circle. In this case the main shaft makes half a revolution, and the wheel Y
goes ten of its teeth, thereby causing ten of the-teeth of the wheel Z to pass
by also, and completing the full forward swing of the oar, and in the
same time the darts upon each part indicate the direction of its motion
during the swing of the oar below its center G. A corresponding motion is
given to the wheel W above and in the opposite direction, and which, there-
fore, can receive no motion upon its perpendicular axis, in consequence of its
following the wheel Z with precisely the same speed which this wheel receives
from the wheel Y, and consequently the feathering wheel W remains rela-
tively without motion upon its perpendicular axis during the time of its
coming backwards, that is, while the blade of the oar is going forward edgeways
through the water; however, on the wheel W going forwards, and being
opposed to the movement of the wheel Z it gradually turns the feathering
wheel half round, or twenty of its teeth, in the same interval that the oar
performs its backward stroke, and so alternately going forwards upon its
edge again. For vessels that are to be used at sea I prefer using this machi-
nery inside the vessel, as in Figure 6, which represents a cross section of the
vessel's beam. In this case I cause two openings to be made in the vessel's
bottom sufficiently long and wide to admit of two pairs of oars, and
which I call twin oars, one pair in each aperture on each side the keel, such
aperture being inclosed after the manner of wells, sufficiently high above the
general water line of the vessel to prevent water getting into the hold. In
these openings the oars are to be suspended, one on each side of a lever, as
will appear in Figure 6. The oar shafts at their top are to be connected
by a pair of spur wheels, so that the one shall turn the other in a reverse
direction, by means of one feathering wheel only to each pair; the oars, remain-
ing upon their edge and without motion, will not be found to impede the
vessel's progress if under sail by canvas, but rather keep her more steady to
her course, by acting as false keels or lee boards to prevent her going to lee-
ward; they can, however, be drawn up within the vessel at pleasure. Inde-
pendantly of the above described modes of producing the peculiar motion
which I claim the exclusive privilege of using, I also claim such alterations of
proportion and form, as well as materials, as may best answer the purposes
of producing the motion and effect herein-before described and set forth.
In witness whereof, I, the said John Oldham, have hereunto set my hand
and seal this Sixth day of April, in the year of our Lord One thousand
eight hundred and eighteen.
JOHN OLDHAM (L.S.)

page_text: John Brooks, of the City of Dublin, writing clerk, aged twenty years and
upwards, maketh oath, and saith, that he was present when John Oldham, Esqro,
attended before Thomas Ball, Esqre, one of the Masters of His Majesty's High
Court of Chancery in Ireland, on the Sixth day of April, One thousand eight
hundred and eighteen, and duly acknowledged the annexed parchment writing
or Specification. And deponent saith the name Thomas Ball, signed to said
parchment writing, is the proper handwriting of the said Thomas Ball.