IMPROVEMENTS IN PADDLE WHEELS FOR PROPELLING VESSELS
Year: 1856

page_text: LETTERS PATENT to Richard Atkinson Coward, of Laurence Pountney
Lane, in the City of London, for the Invention of "IMPROVEMENTS IN
PADDLE WHEELS FOR PROPELLING VESSELS."-A communication.
Sealed the 21st November 1856, and dated the 11th September 1856.
PROVISIONAL SPECIFICATION left by the said Richard Atkinson Coward
at the Office of the Commissioners of Patents, with his Petition, on the
11th September 1856.
I, RICHARD ATKINSON COWARD, of Laurence Pountney Lane, in the City of
London, do hereby declare the nature of the Invention for "IMPROVEMENTS
IN PADDLE WHEELS FOR PROPELLING VESSELS," to be as follows:--
The distinguishing characteristics of this paddle wheel, and the arrangements
wherein its superiority consists, are as follows:-
In the first place, the number of floats is greatly diminished, for whereas the
usually accepted and hitherto adopted rule has been to allow one float to each
foot in diameter of the wheel, thus placing the floats about three feet apart,
by the present Invention the interval between them is made considerably
greater; for instance, in the common paddle, a wheel of 16 feet in diameter
would have about sixteen floats or paddles, but in the new wheel there would
be only half that number. The diminishing the number of floats will, it is
considered, do away with that churning of the water which may be observed to
take place, in a greater or less degree, with all the other kinds of paddle wheels,
thus saving a considerable portion of the power of the engines, which would
otherwise be expended without producing a proportionate effect in propelling
the vessel. The diminishing the number of floats will, it is considered, have
the effect of allowing the water to get away more freely, and in so far diminish
the retarding effect of a large body of water, which the common paddle wheel

page_text: always carries round with it. When a paddle wheel is set in motion by the
engine, every point on its circumference describes a circle. As, however, the
vessel to which it is attached gradually changes its state of rest to one of
motion, it follows that the centre round which the paddle revolves from a fixed
becomes a moving point, and its periphery, ceasing to describe a circle,
commences to describe a cycloidal curve, more or less curvate, according to the
form of the immersed portion of the vessel, and the consequent slip of the
water. In the generality of steam vessels of fair proportions, the slip is about
one-third the velocity of the paddle, i. e., the velocities of the paddle and of the
vessel are in the ratio of 3. to 2, so that if a circle be described in the paddle
wheel with a radius equal to of that of the paddle arm, it will indicate a point
in the wheel which travels at the same same speed as the vessel moves through
the water. The float boards or paddles of this wheel are made much deeper
than those heretofore used, and they are preferred to be about of the radius.
The greater depth of the float is for the purpose of allowing of its adjustment
to the velocities of the different kinds of vessels to which it may be attached.
Another peculiarity consists in the application of flanges on each side of the
floats or paddles, to which, and to the paddle arm, they are firmly secured by
proper bolts and nuts. These flanges have the effect of adding greatly to the
strength of the wheel, and at the same time they improve the propelling power.
The dimensions of the parts may be varied, and those which experience may
point out as advisable will be adopted. One great advantage which this
Invention possesses must not be lost sight of, namely, that it may be so easily
applied to any of the wheels now in use at a very trifling expense.
It is preferred that, with the exception of the bosses and rings, which,
together with the bolts and other fastenings, should be of iron, the other
important parts should be of wood.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Richard Atkinson Coward in the Great Seal Patent Office
on the 5th March 1857.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, RICHARD
ATKINSON COWARD, of Laurence Pountney Lane, in the City of London, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Eleventh day of September, in the year of our Lord
One thousand eight hundred and fifty-six, in the twentieth year of Her reign,
did, for Ierself, Her heirs and successors, give and grant unto me, the said

page_text: Richard Atkinson Coward, Her special licence that I, the said Richard
Atkinson Coward, my executors, administrators, and assigns, or such others as
I, the said Richard Atkinson Coward, 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 PADDLE WHEELS FOR PROPELLING VESSELS,"
(a communication,) upon the condition (amongst others) that I, the said
Richard Atkinson Coward, my executors or administrators, by an instrument in
writing under my, or their, or one of their hands and seals, should particularly
describe and ascertain the nature of the said Invention, and in what manner
the same was to be performed, and cause the same 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 Richard Atkinson Coward, do hereby
declare the nature of the said Invention, and in what manner the same is to
be performed, to be particularly described and ascertained in and by the
following statement thereof, that is to say:-
DESCRIPTION OF THE DRAWING.
Figure 1 shews a side view, and Figure 2 a transverse section of a wheel
constructed according to the Invention. The distinguished characteristics of
this paddle wheel, and the arrangements wherein its superiority consists, are as
follows:-
In the first place, the number of floats is greatly diminished, for whereas the
usually accepted and hitherto adopted rule has been to allow one float to each
foot in diameter of the wheel, thus placing the floats about three feet apart, by
the present Invention the interval between them is made considerably greater;
for instance, in the common paddle, a wheel of sixteen feet in diameter
would have about sixteen floats or paddles, but in the new wheel there would
be only half that number. The diminishing the number of floats will, it is
considered, do away with that churning of the water which may be observed to
take place, in a greater or less degree, with all the other kinds of paddle wheels,
thus saving a considerable portion of the power of the engines, which would
otherwise be expended without producing a proportionate effect in propelling
the vessel. The diminishing the number of floats will, it is considered, have
the effect of allowing the water to get away more freely, and in so far diminish
the retarding effect of a large body of water which the common paddle wheel

page_text: always carries round with it. When a paddle wheel is set in motion by the
engine, every point on its circumference describes a circle. As, however, the
vessel to which it is attached gradually changes its state of rest to one of
motion, it follows that the centre round which the paddle revolves from a fixed
becomes a moving point, and its periphery, ceasing to describe a circle,
commences to describe a cycloidal curve, more or less curvate, according to the
form of the immersed portion of the vessel and the consequent slip of the water.
In the generality of steam vessels of fair proportions, the slip is about one-
third the velocity of the paddle, i. e., the velocities of the paddle and of the
vessel are in the ratio of three to two, so that if a circle be described in the
paddle wheel with a radius equal to of that of the paddle arm, it will indicate
a point in the wheel which travels at the same speed as the vessel moves
through the water. The float beards or paddles a, a, of this wheel are made
much deeper than those heretofore used, and they are preferred to be about
four-sevenths of the radius. The greater depth of the float is for the purpose
of allowing of its adjustment to the velocities of the different kinds of vessels
to which it may be attached.
Another peculiarity consists in the application of the flanges b, b, on each
side of the floats or paddles to which, and to the paddle arm, they are
firmly secured by proper bolts and nuts. These flanges have the effect of
adding greatly to the strength of the wheel, and at the same time they improve
the propelling power. The dimensions of the parts may be varied, and those
which experience may point out as advisable will be adopted. One great
advantage which this Invention possesses must not be lost sight of, namely,
that it may be so easily applied to any of the wheels now in use at a very
trifling expense.
It is preferred that, with the exception of the bosses and rings, which,
together with the bolts and other fastenings, should be of iron, the other
important parts should be of wood.
In witness whereof, I, the said Richard Atkinson Coward, have hereunto
set my hand and seal, this Tenth day of January, in the year of our
Lord One thousand eight hundred and fifty-seven.
Witness,
W* COWARD,
10, Laurence Pountney Lane.
R. A. COWARD. (L.S.)