CERTAIN IMPROVEMENTS IN MACHINERY OR APPARATUS FOR PROPEL- LING VESSELS ON WATER
Year: 1834

page_text: EASTER AND THE EARL OF ORKNEY'S SPECIFICATION.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
EASTER, of Taplow, in the County of Bucks, Engineer, send greeting.
WHEREAS His present most Excellent Majesty King William the Fourth,
by His Royal Letters Patent under the Great Seal of Great Britain, bearing
date at Westminster, the Twenty-sixth day of July, in the fourth year of His
reign, did give and grant unto me, the said John Easter and Thomas John
Hamilton Earl of Orkney and Taplow aforesaid, His especial license, full
power, solo privilege and authority, that we, the said John Easter and Thomas
John Hamilton Earl of Orkney, our executors, administrators, and assigns, or
such others as we, the said John Easter and Thomas John Hamilton Earl of
Orkney, our executors, administrators, or assigns, should at any time agree
with, and no others, from time to time and at all times during the term of
years therein expressed, should and lawfully might make, use, exercise, and
vend, within England, Wales, and the Town of Berwick-upon-Tweed, our
Invention of "CERTAIN IMPROVEMENTS IN MACHINERY OR APPARATUS FOR PROPEL-
LING VESSELS ON WATER;" in which said Letters Patent is contained a proviso,
that we, the said John Easter and Thomas John Hamilton Earl of Orkney,
or one of us, shall cause a particular description of the nature of our said
Invention, and in what manner the same is to be performed, to be inrolled in
His 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 thereunto had, will more fully and at large

page_text: NOW KNOW YE, that in compliance with the said proviso, I, the said
John Easter, do hereby declare that the nature of our said Invention, and in
what manner the same is to be performed, is particularly described and
ascertained in and by the following description thereof, reference being had
to the Drawing hereunto annexed, and to the letters and figures marked thereon
(that is to say)
Our Invention of certain improvements in machinery or apparatus for pro-
pelling vessels on water consists in a peculiar mode of adapting rotary pistons
in connection with revolving excentric conducting shields, formed by segments
of cylinders sliding one within the other as the pistons go round. In the
accompanying Drawings, Figure 1 is a plan or horizontal view of part of a
vessel in which this improved propelling apparatus is adapted, the top plate
being removed. a, a, are the rotary pistons, each turning horizontally upon its
pivot at bottom in a brass step. Figure 2 shews one of the pistons detached,
in its vertical position, as it would appear when presenting its broad surface,
shewing an aperture through for the free passage of the water within the cylin-
drical shield. The upper part of the spindle of each rotary piston turns in a
brass collar with a stuffing box, and to each of the spindles above is attached
a bevel pinion, which receives the teeth of the driving wheel connected to the
crank shaft of the steam engine. The channels 6, b, b, for the passage of the
water are formed with plates of iron bent to the required curves, and securely
fixed in erect positions by means of flanges bolted to top and bottom plates
c, c, c. The excentric conducting shields are formed by segments of cylinders of
thin metal d, d, and e, e, the latter sliding within the former. The segments are
required to be about two thirds of the circumference of a complete cylinder,
and are enabled to slide round in circular grooves formed in brass rings ff,
fixed by flanges and screws to the top and bottom plates c.
the channels b, b, at g, g, in the sides of the vessel, and is
toward the stern. The rotation of the pistons a, a, cause the water in the
channels b, b, to be taken hold of by the arms of the pistons, projecting from the
cylindrical shields, and the water is thereby forced back toward the stern, with
a similar effect to that resulting from the action of the ordinary paddle wheel,
the vessel being by these means propelled in the opposite direction. It will be
perceived that as the axis of the propelling pistons stand in excentric situa-
tions with reference to the interior of the sliding cylindrical shields, that the
rotations of the pistons will cause the two segments of which each cylinder is
formed to slide with differential movements, according to the position of each
pistou; and in order to reduce the friction of the surfaces they are kept about
an eighth of an inch apart by a thin collar or rim of brass in the grooves of
The water enters
discharged at h, h,

page_text: the rings f, f, at top and bottom. Anti-friction rollers may also be mounted at
the inner edges of the segments to relieve the friction of the pistons. Figure 8
is a longitudinal section of a vessel, in which our improved propelling apparatus
is shewn acting upon a horizontal axis in a vertical direction, and which may be
made of nearly the same width as the vessel. a is the paddle; b, b, the channel
for the water to pass, and which may be made to branch off at the stern to
clear the stern post and rudder; d and e are the two segments of cylinders
working one within the other, as above described. The piston, being made to
revolve by toothed gear applied near the ends of its shaft, will act upon the
water in the same way as other rotary paddles, and propel the vessel forward.
Lastly, we desire it to be understood that we claim as our Invention the
adaptation of the rotary pistons in excentric connection with the sliding seg-
ments of cylinders for the purpose of propelling vessels on water, whatever
may be the position of such pistons and segments of cylinders, or by whatever
means they may be actuated.
In witness whereof, I, tho said John Easter, have hereunto set my hand
and seal, this Twenty-sixth day of January, One thousand eight