Year: 1841

page_text: NOW KNOW YE, that in compliance with the said proviso in the said
Letters Patent and herein-before mentioned, I, the said John Melville, do
hereby declare the nature of my said Invention, and the manner in which the
same is carried into effect, is fully set forth and ascertained in the following
description thereof, and in the Drawings hereunto annexed.
My present Invention may be regarded as an improvement upon a former
Patent granted unto me, bearing date the Eighth day of February, One thou-
sand eight hundred and thirty-eight, and resealed on the Twenty-sixth day of
the same month of February, and consists of simplifications and modifications
of the arrangements therein shewn, chiefly with the view of rendering the
occasional use of steam more readily applicable in sailing vessels engaged in
long voyages. Figures 1 and 2 shew one arrangement for this purpose
(Figure 1 being a side elevation, and Figure 2 a plan), in which only two
propellers are employed. At a is the shaft driven by the engine, to which are
keyed the cranks b, b, placed at the ends of the shaft, and in a direction
diametrically opposed to each other, as distinctly shewn in the plan, Figure 2.
At c, c, are the paddle stems, to which are bolted the floats d, d; e, e, the crank
pins. Each of these works in a journal in the paddle stem c; the upper end
of this stem is jointed to a radius rod f, which vibrates on a central pin g of
the standard h, which inclines outwards from the side of the vessel, so that its
upper end shall be in the same vertical plane as the radius rod and the
stem of the propeller c. The standard is supported upon a flanged bearing
plate, bolted to the side of the vessel. By this arrangement, as the crank
revolves the float becomes depressed into the water, and during its passage
through the same describes à curve, which differs but little from the segment
of an ellipse. I have in some cases found it advantageous to fix counter-
balances on the shaft in opposite directions to the cranks, as shewn by
the red lines. In the case of the engine being of the kind called single-
acting, the cranks b, b, are fixed to the shaft so as to stand in the same
direction, and not in the opposite directions shown in Figures 1 and 2.
In the case of two shafts and two pairs of propellers being deemed
preferable, I place the four cranks as equidistant radii, i. e., at right angles
to each other. This relation of the paddles upon the two shafts, which
may be connected by any convenient mode, is represented in the diagramis
Figures 3 and 4, considered in connection with the Figures 1 and 2.
Figures 5 and 6 exhibit an arrangement of mechanism for dispensing with the
radius or guide rods shewn in Figure 1; Figure 5 being a side elevation, and
Figure 6 an end view. a is the driving shaft; b, the propelling crank; c, the
paddle stems, to which are bolted the paddles or floats d, d. Instead of the

page_text: paddle stem c being guided by radius rods, it is made to slide through a
carriage i, fixed upon a spindle &, which turns in bearings on the standard m.
On the sides of this carriage are two antifriction rollers n, n, whose peripheries
are grooved for the purpose of receiving the bevilled edges of the paddle stem c.
The standard m may consist of a framing firmly bolted to the vessel's side, or
it may be formed, as shewn in the Figures, of a davit turning upon a pivot,
and secured in its proper position by stay rods, as at o, o. In this latter mode
of construction, by lowering the davit into the horizontal position, the float or
paddle can be placed nearly horizontal, at a considerable height out of the
water, so as to offer no resistance to the progress of the vessel when the aid of
the engines is no longer required. Figures 7 and 8 shew another arrange-
ment, upon the same principle as the preceding (Figures 5 and 6), but of.
different construction. Figure 7 is a side elevation, and Figure 8 an end
view. Instead of the paddle stem c working between two guide rollers
situated on a vibrating carriage, a slot is formed in the paddle stem, as at p;
a pin q, firmly fixed to the standard m, passes through this slot; to diminish
the friction between the slot and pin, a roller r is placed upon the latter. The
standard m, as in the last-described arrangement, may either be firmly fixed to
the side of the vessel, or may be formed, as shewn in the Figure, of a davit
turning upon a pivot, and secured in its place by stay rods 0, 0. Instead of
making the slot, as just described, in the stem of the paddle, and fixing the
pin in the standard, I sometimes fix the pin in the paddle stem, and mako
the slot in the vertical standard; but as I prefer the former methods, and as
this is so obvious a modification, I have not thought it necessary to give
Drawings of it. With a view to break the force of the waves, I sometimes
form the float of two planes, meeting at an angle outwards, as shewn in plan
in Figure 9.
Having thus described the nature of my said Invention, and the manner of
carrying the same into effect, I desire it to be understood that I do not claim
all the parts herein described as my Invention; but I do claim,―
First, the propelling of vessels by the employment of two paddles, arranged
and guided as herein-before described, one being placed on each side of the
vessel, and driven by cranks attached to the ends of the engine shaft.
Second, I claim the use of two shafts connected together, and each carrying
two paddles, as herein described, such paddles being caused to enter the water
in regular succession by the propelling cranks upon one shaft standing at right
angles to the propelling cranks on the other shaft, so as to produce a continuous
action in propelling the vessel.
Third, I claim the arrangement before described by which the paddle stems

page_text: are guided, viz., either by causing them to slide over and vibrate about a fixed
point, or by causing a point in the stems to move in a fixed groove or slot.
And such my Invention being, to the best of my knowledge and belief,
entirely new, and never before" used within that part of Her Majesty's United
Kingdom of Great Britain, and Ireland called England, Her said Dominion of
Wales, and Town of Berwick-upon-Tweed, or Her Majesty's Colonies and
Plantations abroad, I do hereby declare this to be my Specification of the
same, and that I do verily believe this my 'said Specification doth comply
fully and in all respects, and without reserve or disguise, with the proviső in
the said herein-before in part recited Letters Patent contained; wherefore I
hereby claim to maintain exclusive right and privilege to my said Invention.
In witness whereof, I, the said John Melville, have, hereunto set my
hand and seal, this Nineteenth day of July, One thousand eight hundred