CERTAIN FURTHER IMPROVEMENTS ON MY FORMER IMPROVEMENTS ON MY FORMER PATENT, BEARING DATE THE TENTH DAY OF OCTOBER, ONE THOUSAND EIGHT HUNDRED AND SEVENTEEN, FOR AN IMPROVEMENT OR IMPROVEMENTS IN THE MODE OF PROPELLING SHIPS AND VESSELS ON SEAS, RIVERS, AND CANALS, BY THE AGENCY OF STEAM
Year: 1820

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
OLDITAM, 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 called England, bearing date at Westminster, the Fifteenth day of
January, in the sixtieth year of His reign, give and grant unto me, the said John
Oldham, my exors; admors, and assigns, His especial licence, full power, sole pri-
vilege and authority, that I, the said John Oldham, my exors, adñiors, and
assigns, during the term of years therein mentioned, should and lawfully might
make, use, exercise, and vend, within England, Wales, and the Town of Berwick-
upon-Tweed, and also in all His Majesty's Colonics and Plantations abroad,
my Invention of "CERTAIN FURTHER IMPROVEMENTS ON MY FORMER IMPROVEMENTS
ON MY FORMER PATENT, BEARING DATE THE TENTH DAY OF OCTOBER, ONE THOUSAND
EIGHT HUNDRED AND SEVENTEEN, FOR 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
performed, 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, will more fully and at large appear.

page_text: 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
improvements consists in the use of certain oars placed on the side or under
the vessel to be impelled, but which oars, instead of oscillating in a.pendulous
manner and returning through the water edgeways at each alternate swing or
oscillation, as described in my aforesaid former Patent of the Tenth day of
October, One thousand eight hundred and seventeen, I cause to preserve a
continuous revolving motion. My said improvements further consist in feather-
ing the oars by a continuous and revolving motion instead of an intermitting
one, and by which their motion is completely different in principle and action
from anything hitherto used; the great object and design of this my improve-
ment being to contain a continuous motion in all parts of the machinery
employed; and the manner in which I effect this will appear from the following
description and reference to the explanatory Figures or Drawing hereunto
annexed.
Fig. 1 represents a view of one pair of oars in their vertical or working
position, as seen from the head or stern of the vessel on which they are fixed,
a section of which is shewn in the Figure. Fig. 2 also represents a similar
view of one pair of oars when they are in their horizontal position or out of the
water. Fig. 3 represents a ground plan of a pair of oars in the same position.
Fig. 4 represents a side view of the oar with a connecting beam or rod herein-after
described. A represents the side of the vessel; B, an outer beam placed to
support or cary the exterior plummer blocks of C, the main axle or centre of
motion of the oars; D, a bevel wheel firmly attached to the side of the vessel, and
through which the axle C turns freely; E, a bevel wheel of similar dimensions
keyed or otherwise fixed upon the oar shaft nearest to the vessel's side;
F and G, two oar shafts, made of wrought iron or other sufficiently strong
metal, passing through the main axles and freely turning therein; H, a metal
beam or plate, a side view of which is seen at Fig. 4, firmly fixed to the main
axle; K and K, two double metal sockets through which the oar shafts freely
turn; these sockets are fixed by keys or otherwise to the projecting end of the
beam or plate II, and are intended to strengthen and keep the oar shafts in
their place, and to take off the friction and strain of the action from the main
axle C; L, L, two spur wheels of equal diameters turning into each other
and keyed to their respective oar shafts; M, M, M, M, the double oars, made
of iron or timber, their ends being keyed firmly into the shafts with a provision
for being liberated or lengthened, if necessary; N, four brass washers; O, four
metal washers to keep the oar shafts in their places. The action of the whole
will now be apparent. The main axle in its revolution turns the oar shafts

page_text: after the manner of the arms of a water wheel, by means of the bevel wheels
D and E; the near oar shaft obtains a revolving and continuous motion on its
own longitudinal axis, and makes one full revolution for each revolution round
the main axle C, or principal centre of motion; by means of the spur wheels
L, L, the inner oar shaft gives to the outer one a corresponding motion, but in
an opposite direction. These oars may be used singly or in pairs, but in the
opposing direction of the twin oars as here described, and which I prefer,
depends in a great measure the easy and uniform action of the whole appa-
ratus, since by this contrivance all lateral pressure is counteracted. By this
description it is evident that the oar shafts make one half revolution on
their longitudinal axis, and prevent a gradually increasing and diminishing
power of resistance to the water while passing from the horizontal position, as
described in Fig. 2, until they have again arrived at the same position. The
revolutions of the oar shafts round their longitudinal axes may be multiplied by
diminishing the size of the bevel wheel E, so that the oars may make one and
an half or two revolutions on their longitudinal axes for each revolution upon
their principal centre of motion. Should it be expedient to cause the oars to
make their working or active half revolution while a quarter of the great
circle is described by their motion round the main axle C, rather than in half
of it, as described above, this may also be effected by means of the crank
motion, as described in my former Patent, and as here shewn in Fig. 3, by
means of the additional wheels P and Q, with the connecting rod R. In this
case the bevel wheel D, instead of being a fixture on the side of the vessel, is
connected with the crank S and the socket T, all of which turn together freely
on the main axle C, the wheel P being double the size of wheel Q; but this
action is fully described in the Specification of my aforesaid former Patent,
with this difference only, that it is there' described as applying to the vibratory
or oscillating motion of the oȧrs, while I now apply it to the continuous
circulating motion of them, as above stated.
The foregoing details are given for the more full and perfect understanding
of the Invention, and these my improvements in the use of my oars or paddles
in the propelling vessels by the agency of steam or other power, as described
in my former Patent; but the parts thereof, and the improvements for which I
here claim the sole and exclusive use and privilege and enjoyment, consist in
having oars or paddels on both extremities of the oar shafts, and in giving a
continuous and revolving motion to the same, instead of a pendulous or
oxcillating one, both on their longitudinal and central or principal axis.
.
A further peculiarity and object in these my improvements is, that by
placing oars on both ends of the oar shafts, and by giving them a revolving

page_text: action round the main axle, they may be effectually set at rest in an horizontal
position, as described at Fig. 2, when they are completely out of the water,
by which important circumstance every impediment to the vessel's sailing is
removed, whenever it may be adviseable to have recourse to sails alone, a
circumstance of the utmost importance, as it thus effectually combines the
advantages of sailing either by wind or steam, and without impediment to
either. I do not mean to confine myself to the form,, number, or dimensions
of the oars, oar shafts, framework, beam, or wheel work, as shewn in the
annexed Figures, or to the manner of fixing or arranging the same, as these
are only some of the many modes in which my said Invention and improve-
ments may be made or applied, as must be evident to every mechancic; for
instance, instead of-the oar shafts passing through the main axle, and being
made to revolve by the action of only one bevel wheel on the near oar shaft,
the, oars on the opposite side of the main axle may be made to act indepen-
dently of each other, with their centers turning in the same, and made to
revolve longitudinally by means of separate wheel work. By this means, this
my improvement may be easily attached to the outside of any steam boat,
and without the necessity of having main axles, as described in the annexed
plan....
In witness whereof, I; the said John Oldham (party hereto), have
hereunto set my hand and scal, this Ninth day of June, in the year
Inrolled the Tenth day of July, in the year of our Lord One thousand 3
eight hundred and twenty..