CERTAIN IMPROVEMENTS ON THE MACHINERY FOR PROPELLING VESSELS
Year: 1825

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
HOPKING HILL, of Woolwich, in the County of Kent, Lieutenant in the Royal
Artillery, send greeting.
of
WHEREAS His present most Excellent Majesty King George the Fourth,
by His Letters Patent under the Great Seal of Great Britain, bearing date at
Westminster, the Twenty-sixth day of February, in the sixth year of His
reign, did, for Himself, His heirs and successors, give and grant unto me, the
said William Hopkins Hill, His especial licence, that I, the said William
Hopkins Hill, my exors, adiñiors, and assigns, or such others as I, the said
William Hopkins Hill, my exors, admors, and assigns, should at any time
agree with, and no others, from time to time and at all times during the term
years therein expressed, should and lawfully might make, use, exercise, and
vend, within England, Wales, and the Town of Berwick-upon-Tweed, and also
in His said Majesty's Colonies and Plantations abroad, my Invention of
"CERTAIN IMPROVEMENTS ON THE MACHINERY FOR PROPELLING VESSELS;" in
which said Letters Patent there is contained a proviso obliging me, the said
William Hopkins Hill, by an instrument in writing under my hand and seal,
particularly to describe and ascertain the nature of my said Invention, and in
what manner the same is to be performed, and to 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 in part recited Letters Patent, as in and
by the same, reference 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
William Hopkins Hill, do hereby declare that the nature of my said im-
provements, and the manner in which the same are to be performed, are
particularly described and ascertained in and by the Drawing hereunto an-
nexed, and the following description thereof (that is to say) :-
Instead of using a number of fixed paddling boards upon the circumference
of the body of a wheel, as in present general use, I attach to the body of a
wheel, at equidistant points of the circumference, four paddle boards having
movement upon horizontal axes, the paddle boards having each a lever attached
(see Figs. 3 & 4), with branched or forked arms. The arms of the different
paddles have a particular and relative position to each other, explained in
Figs. 1 and 2, so that by connecting their heads by short connecting rods a par-
ticular quantity of alternating movement is permitted to the paddles; this alter-
nating movement is reciprocating between paddle and paddle, and is effected
on the rotation of the wheel by the resistance of the water against which they act,
(that is to say,) that the movement of one paddle upon its axis causes thereby
the movement of the next in a contrary direction, and so on around the circle.
Fig. 3 is a front view of a paddle complete, as attached to the arms of the wheel
in a vertical position, and shews also the position of the framing or cross bracing
of the principal arms of the wheel. Fig. 4 is a side view of a paddle lever
attached to a section of the paddle board. Fig. 5 is a side view of one of the
straps attached to a section of the paddle board. Fig. 6 shews the form of
the connecting rod or link of the paddle levers. In Figs. 1 and 2 the body of
the wheel is omitted the better to shew the paddle levers, their action, and the
geometrical lines explanatory of the construction and movement. In these two
Figures the lines a, b, a, b, shew the water line. Fig. 1 exhibits the four
paddles radiating from the axis of the wheel, one paddle being then vertical in
the water. Fig. 2 shews the equal immersion of two paddles, and the full
quantity of their reciprocated action. The dimensions of those parts of the
wheel and mechanism connected with the movements are geometrical, and in a
ratio with the distance of the axis of the wheel from the surface of the water,
the water line being a side of the inscribed square to the circle upon which the
paddle axes are situated (as shewn in Fig. 2), so that when two paddles are
equally immersed the water line cuts them upon their axes of movement. In
Figs. 1 and 2 four connecting rods are shewn between the paddle levers, but
I am of opinion that for practice one might better be withdrawn, as the con-
nection between the four levers may be effected by three, and any small
deviation from geometrical correctness in the construction would not so much
affect the movement as with the circle completed. Here also it is to be observed

page_text: is a provision in case of accident to any one of the lever arms so connected, by
shifting the connecting rod to the other arms. Fig. 7 explains the construc-
tion of the body of a wheel suited to receive the paddles and internal movement.
The principal object to be attended to is to keep the cross or diagonal bracing
free of the paddle levers; this I have effected by extending the four principal
pairs of arms beyond the outer rim of the wheel, giving the projecting parts of
the arms greater strength, and then bracing them crossways from the position
of the rim to the centre plate in the directions shewn at l, m, Figs. 3 and 7. This
cross bracing occurs at each of the four principal pairs of arms; a portion only
of the body of the wheel is shewn, the other parts being the samo repeated.
Fig. 8 is a diagram explaining the position of the paddles during a half
revolution of the wheel. In assistance of the paddle movements I am of
opinion that a small superiority of paddling surface below or without the axis
of the paddles may be preferable to their turning upon their centres of surface.
The geometrical construction of the parts constituting the movements is as
follows:-Having described a circle, having the axis of the wheel as a centre,
and the water line a side of the inscribed square, take an angle of the inscribed
square c, Fig. 1, as a centre, and with a side of the inscribed octagon as radius
describe the arc d, e, f, g; also from an adjacent angle of the same square at k
describe a similar are h, f, i, n; then it is to be seen in this Figure that the
head or joint d of one arm of the paddle lever falls upon the intersection of the
are d, e, f, g, with the side of the square c, d, and the head of the other arm at
the intersection of the two arcs at f, the stem or principal part of the lever
falling upon the radius of the circle. The length of the connecting rod is tho
chord of one fourth of the arc or quadrant d, e, f, g. Having given a descrip-
tion of the various particulars necessary to be attended to in the construction
of this mechanism, I have to observe that the object I have in view in these
improvements is a better and more perfect application of the propelling
power.
In this Specification I claim as my Invention the peculiarities of the paddle
movements, namely, their reciprocating action upon each other as described.
I do not mean to claim the movement of paddle boards upon horizontal
axes, but the peculiar application of that movement. I also disclaim the
different parts constituting this mechanism which are in general use, but
claim those peculiarities of construction, proportion, and arrangement necessary
to effect the paddle movements before described. I do not limit myself to
the number of four paddles, nor to the particular quantity of their alternating
movement, although I believe those set forth to be the best; neither do I

page_text: confine myself to the precise method of effecting the reciprocating action of tho
paddles.
In witness whereof, I, the said William Hopkins Hill, have hereunto set
my hand and scal, this Twenty-fifth day of August, in the year of our
Lord One thousand eight hundred and twenty-five.
AND BE IT REMEMBERED, that on the Twenty-fifth day of August, in
the year of our Lord 1825, the aforesaid William Hopkins Hill came before
our said Lord the King in His Chancery, and acknowledged the Specification
aforesaid, and all and every thing therein contained and specified, in form abovo
written. And also the Specification aforesaid was stamped according to the
tenor of the Statute made for that purpose.
Inrolled the Twenty-fifth day of August, in the year of our Lord One
thousand eight hundred and twenty-five.