IMPROVEMENTS IN PADDLE WHEELS FOR PROPELLING VESSELS BY STEAM OR OTHER POWER
Year: 1840

page_text: RAPSON'S SPECIFICATION.
TO ALL TO WHOM THESE PRESENTS SHALL COME I JOHN
RAPSON, of Limehouse, in the County of Middlesex, Millwright, send
greeting.
WHEREAS Her present most Excellent Majesty Queen Victoria, by Her
Letters Patent under the Great Seal of Great Britain, bearing date the
Westminster, the Third day of, November, in the fourth year of Her reign,
did, for Herself, Her heirs and successors, give and grant unto me, the said
John Rapson, Her especial licence, full power, sole privilege and authority,
that I, the said John Rapson, my exors, admiors, and assigns, or such others as
'I, the said John Rapson, my exors, admors, or assigns, should' at any time
agree with, and no others, from time to time and at all times during the
term of therein expressed, should and lawfully might make, use, exercise,
and vend, within England, Wales, and, the Town of Berwick-upon-Tweed,
my Invention of "IMPROVEMENTS IN PADDLE WHEELS FOR PROPELLING VESSELS BY
STEAM OR OTHER POWER;" in which said Letters Patent is contained a proviso,
that I, the said John Rapson, should. cause a particular description of the
nature of my said Invention, and in what manner the same is to be performed,
to be inrolled in Her said 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 appear.
NOW KNOW, YE, that in compliance with the said proviso, I, the said John
Rapson, do hereby, declare that the nature of my said Invention, and the manner
in which the same is to be performed, are fully described and ascertained in 'and

page_text: by the following statement thereof, reference being had to the Drawing here-
unto annexed, and to the figures and letters marked thereon (that is to
say) :-
-
My Invention relates to applying hollow vessels to paddle-wheels in place
of the float-boards or paddles now employed, whereby, in causing such hollow
vessels to be immersed in the water by the rotations of the wheels, such
vessels will offer greater resistance to the power of the engine, and thus cause
the vessel to be propelled more advantageously; and the hollow vessels, in
passing the perpendicular when under the water, will, by their levity, tend to
rise to the surface of the water; thus requiring less of the engine's power here-
tofore requisite for raising what is called back-water. And in order to give the
best information in my power, I will proceed to explain the Drawing hereunto
annexed.
DESCRIPTION OF THE DRAWING..
Figure 1 represents the section of a steam vessel, having two. paddle-wheels,
constructed according to my Invention, applied thereto; Figure 2 is a side view
of one of the wheels separately; Figure 3 shows a plan of one of the hollow
vessels separately, which I prefer to be of copper, but they may be made of
any suitable material; and Figure 4 is a cross section of a wheel shewn sepa-
rately. In each of these Figures the same letters indicate similar parts; a, a,
being the hollow vessels, which I prefer to be of the shape shewn, as that
shape will be found to enter and leave the water most advantageously; at the
same time I do not confine myself to the precise form, so long as they are
hollow, and consequently offer greater resistance, when entering the water, to
the power of the engine or engines employed for propelling; b, b, shew the
side framing of the wheels; and c, c, the diagonal braces, to give stiffness to
the outer framings of the wheels, for it will be seen that the main or paddle
'shaft d does not pass to the outer framing. I would, however, remark, that,
if desired, the shaft d may be longer, and have both the side framings of the
wheel affixed thereto. The hollow vessels are affixed to the side framings of
the wheel, as is clearly shown in the Drawing; and it will be evident that,
in using paddle-wheels constructed according to my improvements, the hollow
vessels will act by their buoyancy in place of the mere surface action of float-
boards or paddles of the construction heretofore used, which did not, when
made of iron, in any way act by buoyancy, and, when made of wood, the
quantity of buoyancy brought into operation has been of little value.
Having thus described the nature of my Invention, and the manner of
performing the same, I would have it understood, that what I claim is the