CERTAIN IMPROVEMENTS IN PROPELLING
Year: 1850

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, ALEXANDRE
HEDIARD, of Paris, in the Republic of France, Gentleman, send greeting.
WHEREAS Her present most Excellent Majesty Queen Victoria, by Her
Royal Letters Patent under the Great Seal of Great Britain, bearing date at
Westminster, the Twenty-first day of February, in the thirteenth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me, the
said Alexandre Hédiard, Her especial license, full power, sole privilege and
authority, that I, the said Alexandre Hédiard, my exors, adiñors, and assigns,
and such others as I, the said Alexandre Hédiard, my exors, aditiors, or
assigns, should at any time agree with, and no others, from time to time and
at all times during the term of years therein mentioned, should and lawfully
might make, use, exercise, and vend, within England, Wales, the Town of
Berwick-upon-Tweed, and in all Her Majesty's Colonies and Plantations
abroad, and in the Islands of Jersey, Guernsey, Alderney, Sark, and Man, my
Invention of "CERTAIN IMPROVEMENTS IN PROPELLING;" in which said Letters
Patent is contained a proviso obliging me, the said Alexander Hédiard, 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 Her 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, refer-
ence being thereunto had, will inore fully and at large appear.

page_text: NOW KNOW YE, that in compliance with the said proviso, I, the said
Alexander Hédiard, do hereby declare that the nature of my said Invention,
and the manner in which the same is to be performed, is particularly de-
scribed and ascertained in and by the following description thereof, reference
being had to the Drawings hereunto anuexed, and to the letters and figures
marked thereon (that is to say) :-
The Invention for which I have obtained Her Majesty's Letters Patent as
aforesaid relates to the employment of submerged propellers of a peculiar
construction. One side only of this propeller acts upon the liquid element,
which serves as the point of resistance, whilst the opposite side of the propeller
remains open to and in communication with the atmospheric air. In order
clearly to understand this improved principle or means of propulsion, it will
only be necessary to suppose that at the stern or hinder part of a vessel is
adapted a piston or moveable piece of a similar character, and that the move-
able piece or piston should be capable of moving back and forth between the
external water in which the vessel floats and the atmospheric air in the
interior of the vessel in a chamber provided for the purpose within the vessel.
This moveable piece or piston, when worked or actuated by some suitable
motive power or agent, will necessarily propel the vessel, as the propeller, when
pressed against the water in the first instance, will meet with a considerable
amount of resistance, and will not force back the water except by the employ-
ment or exertion of a certain amount of power or force which will be trans-
mitted to the vessel, and make it advance in an opposite direction. When by
a reverse motion the propelling agent shall be drawn back previous to making
another stroke, it will encounter no resistance which would tend to counteract
or neutralize the effect already produced. On the contrary, the whole of the
column of water in which the propelling agent is submerged will act upon the
surface of the propeller, and thereby assist its retrograde movement. An
essential condition for the proper operation of this propelling agent (whether
it be a piston or any other suitable contrivance) is, that notwithstanding its
reciprocating motion, it should form with the sides of the vessel, or with the
stationary or fixed parts to which it is adapted or fitted, a perfectly close joint,
through which neither air nor water can pass. With an apparatus arranged
and adjusted in this manner, a lower stratum or body of water may be acted
on than with the screw, and a very great amount of resistance will be obtained.
One grand advantage over the screw will be, that the propelling agent above
mentioned will act by direct pressure, instead of in an oblique direction, upon
the resisting medium.
The means of applying this principle to the propulsion of vessels will

page_text: be the best understood by a reference to the accompanying Drawings.
Let us suppose that a steam vessel of the ordinary kind is provided and
furnished with its boiler and engines, but without its paddle-wheels and their
appurtenances, instead of which two pistons or propellers, arranged parallel to the
keel, are placed at the hinder part of the vessel. These pistons, being actuated in
their cylinders (which I shall call propelling cylinders) by means of the engine,
have a reciprocating motion communicated to them, and the vessel is thereby
caused to advance. However, as it is sometimes necessary to make the vessel
recede, I have provided for such cases, without changing the motion of the pistons,
by merely turning the current of water forced out by their action by means of a
moveable inclined vane or shutter, which, when lowered down in front of the
pistons, will, by being set at an acute angle, direct the water that is acted
upon by the pistons towards the bows of the vessel. The power of the
pistons, of which power this water is only in effect a prolongation, will then
act in a contrary direction, and cause the vessel to retrograde or move
backwards.
Figures 1, 2, 3, 4, 5, 6, and 7 represent various views of parts of a vessel
built or constructed upon the same keel as ordinary vessels. At the hinder
part, and beside the keel, are two pistons or propellers working in cylinders,
the inner ends of which are open to the interior of the vessel, although the
pistons or propellers move and act in the open water. Figures 1, 2, and 8
are intended particularly to shew the position in the vessel of the propellers
and their appendages, and also to represent the alterations which will be
necessary in the form and construction of the vessel. Figures 4, 5, 6, and 7
are sectional views taken at different parts of the vessel and the apparatus, in
order that the details and adjustment of the parts may be more clearly
understood.
Fig. 1 represents the lines or profiles of the vessel as presented by vertical
transverse sections taken at different points, as indicated by the small
letters a, b, c, d, e, f, g. This section is divided vertically from the line of
flotation into water lines numbered as shewn in the Figure. The continuation
in red of the profile lines a, b, c, d, e, f, g, indicate what they would have been
if the vessel had preserved its ordinary form, and they consequently shew by
comparison with the black lines the amount of alteration that the hinder part
of the vessel requires to undergo in order that the new system may be
adapted thereto. The two circles at the sides of the keel represent the place
where the pistons or propellers and cylinders are to be placed.
Fig. 2 represents the lines obtained by taking horizontal sections of the
vessel at different heights from the keel up to the floating line. The lines are

page_text: marked with small letters and figures to correspond to Fig. 1. The water
lines drawn in red indicate what they would have been if the vessel had pre-
served its ordinary form. The situation of the cylinders, pistons, or propellers,
and other parts herein more particularly referred to, are shewn by lines in the
Figure.
Fig. 3 is a longitudinal elevation of the hinder part of the vessel, and
represents the lines produced by taking sections in the lines A, A, and B, B,
of Figures 1 and 2.
Figures 4 and 5 are transverse vertical sections of the vessel and propelling
cylinder taken in the lines A, A, of Figures 3 and 6.
Fig. 5 is a detached sectional view representing the two registers or plates
whereby the entrance to the propelling cylinders may be closed when required
by simply lowering the registers. This is done for the purpose of preventing
the water from entering the propelling cylinders when it may be necessary to
repair or dismount the pistons or propellers. These register or plates are
accurately fitted and made to slide in grooves attached to the sides of the
vessel. They are mounted above the propelling cylinders, and are worked by
means of screws or any other suitable contrivance.
Fig. 6 is a longitudinal vertical section (in the line B, B, of Figures 1
and 2) of one of the propelling cylinders, with its position or propeller and
other appendages.
Fig. 7 is a horizontal section (in the line B, B, of Figures 5 and 6.) of the
propelling cylinders and the pistons or propellers, with their rods and the open
air-chamber.
These Figures represents more clearly the peculiar construction of the
pistons or propellers, which require a more detailed description. Each piston
or propeller is composed of two parts. The first is a disc, which is furnished
with packing, by means of which it is made to accurately fit the cylinder, as in
ordinary pistons. The second part is an appendage, either solid or hollow,
and made of metal or other suitable material. It is made to fill the cylinder
without friction, and is prolonged externally, so as to carry the action of the
piston or propeller altogether beyond the mouth of the cylinder, and prevent
the column of water from following the piston to the inner end of the cylinder
when it recedes. The surface of the outer end of this appendage is made
slightly concave, in order that in its action it may meet with the maximum
resistance of the water. In order to facilitate its adaptation or removal, this
appendage may, if required, be made either in one or more parts. In the
Drawing it is represented as constructed of two parts, connected together by a
disc, which is attached or secured at its centre to a prolongation of the rod of

page_text: the piston or propeller. This prolongation is extended even to the outer end
of the before-mentioned appendage, which is secured to it at the centre by
means of a nut. Behind the propelling cylinders, and inside the vessel, is
built a water-tight chamber, which communicates at its lower part with the
two pistons or propellers and their cylinders; and its upper part, which is
open to the atmosphere, rises above the floating line or water level, so that,
even should an accident happen to the cylinders or any of the parts connected
therewith, and thereby open a way for the water to enter the chamber, the
vessel would be protected by this chamber, and the water prevented from
entering the vessel. This chamber is furnished with a door, which opens a
communication, when required, with the interior of the vessel. The door is
hermetically closed, and being placed opposite the piston or propeller, it will
serve as a passage whereby the piston or propeller may be withdrawn into the
interior of the vessel when any repairs are needed.
The same letters of reference indicate similar or corresponding parts on
the several Figures, and therefore, after the above explanation of the con-
struction and operation of the several parts, it will only be necessary to briefly
mention the parts to which the letters refer. The cylinders in which the
pistons or propellers work are seen at C, C, and the pistons or propellers
at D, D. The appendage or prolongation of the pistons or propellers is shewn
in Figures 6 and 7 at D', D'; and D" and D" are the rods whereby motion is
communicated to the pistons or propellers from the motive power employed.
E, E, Figures 5 and 6, are the registers or plates whereby the mouths or
outer ends of the propelling cylinders are closed when required; and F is the
inclined vane or shutter for directing the water from the propelling cylinders
in the opposite direction, and thereby causing the vessel to recede or move
backwards. G is the open air-chamber, and G' a door communicating with
the interior of the vessel for the purpose of facilitating the examination or
withdrawal of the pistons or propellers. The parts marked H, H, represent
the sides or timbers of the vessel, and J is the keel.
Figures 8, 9, 10, and 11 represent different views of a vessel constructed
with two keels, and shewing the method of adapting the Invention to a vessel
of this description. The pistons or propellers are placed between the two
keels, and act in a sort of canal formed by the double keel, and communicate
below with the water in which the vessel floats.
Fig. 8 is an end elevation or view of the stern of a vessel with a double
keel and the two propelling cylinders. Fig. 9 is a longitudinal elevation of
the vessel.. Fig. 10 is a horizontal or plan view of the same, shewing the two
keels, between which is marked the place for the propelling cylinders and the

page_text: pistons or propellers. Fig. 11 is a transverse vertical section of the vessel
taken in the line A, A, of Figures 9 and 10.
Besides these two arrangements, it will be evident that the Invention may
be applied in other manners, depending upon circumstances, such as the
particular purpose for which the vessel is to be employed, whether for ocean
or inland navigation.
Whatever may be the relative value of the arrangements above described,
it may be as well to remark that the first plan may be applied either to new-
built ships specially constructed for the purpose, or to ordinary ships or vessels
constructed for the screw or paddle-wheels, as such vessels may be easily and
with certainty made available for the purpose by merely making a few trifling
alterations in the lower part of the after part or stern of the vessel; whereas
the second plan, with its double keel, will only suit and can only be applied to
entirely newly built ships. It may be as well also here to remark, that the
piston or other propelling agents may be placed, not only at the hinder part or
stern of the vessel, but at the sides or at any other convenient or suitable part
of the vessel, provided that they have communicated to them an impelling or
propelling motion parallel to the keel; and I do not limit myself to the
number of the propellers I intend to employ, as they may be either increased
or diminished.
Having now described my Invention, and the best means with which I am
acquainted for carrying the same into effect, I would observe in conclusion
that I claim as the Invention secured to me by the herein-before in part
recited Letters Patent,-
First, the employment of one or more pistons or propelling agents, acting
by one of their faces upon the water near the bottom of the vessel, while the
opposite face of the pistons or propelling agents, being open to or in free
communication with the external atmosphere, will experience no resistance
during the reciprocating motion of the propellers.
Second, the application of one or more pistons or propellers elongated by the
appendage above described.
Third, the employment of the inclined vane or shutter above described, and
intended to change the direction of the impelling force, and cause the vessel
to recede or move backwards.
Fourth, the employment of a slide or shutter for closing the entrance of the
propelling cylinders, as above described.
Fifth, the air-chamber adapted to the inner end of the propelling cylinders
in the interior of the vessel, in order to prevent the water from entering the
vessel in case of accident.

page_text: Sixth, the peculiar construction above described of the hinder parts of the
vessel.
Seventh, the construction or arrangement of a vessel with a double keel for
receiving the propelling agents, as above described.
Eighth and lastly, I claim generally all the applications of which the
principle above described is susceptible, and which may be employed in sea or
river navigation.
In witness whereof, I, the said Alexandre Hédiard, have hereunto set my
hand and scal, this Thirteenth day of August, in the year of our Lord
One thousand eight hundred and fifty.
ALEXANDRE (L.s.) HÉDIARD.
ALEXANDRE (L.S.) HÉDIARD.
Taken and acknowledged by Alexandre Hédiard (party hereto) at Paris, in
the Republic of France, the Thirteenth day of August, One thousand eight
hundred and fifty, before me,