CERTAIN IMPROVEMENTS IN PROPELLING VESSELS
Year: 1828

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
MELVILLE, of Upper Harley Street, Cavendish Square, in the County of
Middlesex, Esquire, send greeting.
WHEREAS His most Excellent Majesty King George the Fourth, by His
Letters Patent under the Great Seal of Great Britain, bearing date at West-
minster, the Eighteenth day of September, in the ninth year of His reign,
did give and grant unto me, the said John Melville, my executors, adminis-
trators, and assigns, His especial licence, full power, sole privilege and
authority, that I, the said John Melville, my executors, administrators, and
assigns, 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, and also in all His Majesty's Colonies and Plantations
abroad, my Invention of "CERTAIN IMPROVEMENTS IN PROPELLING VESSELS;" in
which said Letters Patent there is contained a proviso obliging me, the said
John Melville, under my hand and seal, to cause a particular description of
the nature of my said Invention, and in what manner the same is to be per-
formed, to be enrolled in His Majesty's High Court of Chancery within six
calendar months next and immediately after the date of the said recited Letters
Patent, as in and by the same, relation being thereunto had, will more fully
and at large appear.
NOW KNOW YE, that in compliance with the said proviso, I, the said John
Melville, do hereby declare that my said improvements are intended to apply to
the propelling of vessels by steam or other power, in a line parallel with the
direction of the vessel's course, in such a manner as that the propelling apparatus
shall be little or no impediment to the progress of the vessel when under sail, and

page_text: be capable of ready application when the sails cease to act, thereby obtaining,
as may be necessary, the advantages of motion, either by the ordinary use of
wind, or by my mechanical means, as herein-after described. I, moreover, in
compliance with the said proviso, declare the nature of any said improvements
to be explained in the following description thereof, reference being had to the
annexed Drawings:-
I have three methods of effecting my object, each of which I propose to use
jointly, in pairs, or severally, as circumstances connected with the size, form,
and stowage of the vessel may render most advantageous.
The method which I shall first describe, and therefore denominate my first
method consists in placing on each side of the vessel two pairs of folding
paddles, represented by A, A, Figure 1, their form in plan being also shown at
A, a, a, in Fig. 2, the other two pairs being precisely similar but situated on
the farther side of the vessel. These folding paddles are made of any suitable
material, metal or wood, and of a size proportionate to the size and required
speed of the vessel. The paddles are attached by hinged joints to the beams or
stems B, B, which form part of the traversing frames C, C, and they fold or
shut up, and present only their edges to the water when moving forwards, but
open or expose a large surface to it when moving backwards, being prevented
by the stops and the connecting braces a, a, represented in plan by Fig. 2,
from expanding beyond any assigned angle. The traversing frames C, C, are
kept to the side of the vessel by grooved guides D, D, D, D. These paddle
frames are furnished with friction rollers F, F, F, F, at the ends, and e, e, c, e, at
their middles, to keep them steady, and to facilitate their motion in the guides.
On the frames to which the paddles are attached are toothed racks E, E, which
are acted upon by the toothed wheels F, F, the axes of which pass quite through
the vessel and terminate in similar wheels, which act upon similar traversing racks
on the opposite side of the vessel. To the piston rod of the steam engine whose
cylinder (which may be either situated above or below the plane of the axis)
is placed in a position somewhat inclined, as represented by G, is attached a
rod H, I, (supported by guides,) which passes under a pinion on the axis of
one pair of the wheels, and over a pinion on the axis of the other pair
of wheels, or vice versa. The parts of the rod passing under the one pinion
and over the other are furnished with racks, whose teeth act upon the pinions,
and thus by the alternating motion of the piston of the engine cause one pair
of the paddles to move forwards while the other pair is moving backwards; in
this manner one pair of the paddles is kept continually in action. The paddle
stems or axes which, with the braces I, I, I, I, are bevelled off to an acute
angle on one side, are attached by hook-and-eye hinges to the upper parts of

page_text: the traversing frames and to the lower parts by screw bolts, represented at k, k;
and by this arrangement the paddles can be unshipped and removed from the
side of the vessel whenever the state of the wind renders their application
unnecessary. The upper grooved guide D, D, is attached to the side of the
vessel in such a manner as to admit of its being adjusted according to the
dimensions or wearing away of the traversing frame.
The second method consists in attaching similar folding paddles to the ends
of two or more metal rods (with guides and supports such as may be necessary)
projecting through stuffing boxes under the water lines in the stern of the vessel.
These projecting rods, represented by R, R, R, Figs. II. and III., are con-
nected with the piston of a steam engine by means of a rack and pinions,
represented by B and C, Fig. 2, and a toothed wheel D. The projecting rods
have flush joints at E, E, secured by two bolts, one of which is the pivot
of the joint, and the other for keeping the rod straight. When the rod is
detached from the rack, and its holding bolt withdrawn, it may be pushed out
'till the joint is free to turn outside the vessel, when the end which carries the
paddle may be elevated out of the water so as to admit of the paddle being
removed; after which the rod is again let down, and drawn inwards, until the
whole be within the vessel, except its end, which must be left in the whole or
stuffing box to prevent leekage, so that there are no exterior appendages
except when the paddles are in action.
Fig. 4 represents the third method, where A, B, is a double-acting pump
connected with a steam engine, the cylinder of which is in a parallel position.
C, D, are two supply pipes from the bows of the vessel. F, F, are pipes leading
towards the stern and terminating in the air vessel G. H, I, are pipes of
discharge, the apertures of which, at their terminations h, i, are diminished in
proportion to the velocity required in the vessel's speed, and have the form
best adapted for obtaining the greatest effect. k, l, m, n, are four valves, two
of which open into the pump, and two into the air vessle. Supposing the
piston moving in the direction from A to B, the valve will shut whilst the
valve will open and admit the water into the pump through the pipe c;
the water on the opposite side of the piston having been previously admitted
through the pipe D, will then be forced through the pipe F, and valve n, into
the air vessel, and from thence be expelled through the discharge pipes
at h and i; when the pispot moves in the contrary direction a similar eflect
takes place through the pipes D and E; and thus a continual propelling
action is produced. The circumference of the piston of the pump is not intended
to touch any portion of the cylinder, but to move entirely free of it, the rod
of the piston passing through the stuffing boxes A and B at its ends.