CERTAIN IMPROVEMENTS IN PROPELLING BOATS AND VESSELS
Year: 1823

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
MARTIN HANCHETT, of Crescent Place, Blackfriars, in the City of London,
send greeting.
WHEREAS His present most Excellent Majesty King George the Fourth,
in and by His Letters Patent under the Great Seal of Great Britain, dated
at Westminster, the Twelfth day of April last, did give and grant unto me,
the said John Martin Hanchett, my exors, admors, and assigns, His Majesty's
special licence, full power, sole privilege and authority, that I, my exors, adñiors,
and assigns, and every of us, by ourselves, and our deputies, servants, or agents,
or such others as I, the said John Martin Hanchett, my exors, adñiors, and
assigns, shall from time to time and at all times hereafter appoint, during the
term of years therein expressed, shall and lawfully may make, use, exercise,
and vend my Invention of "CERTAIN IMPROVEMENTS IN PROPELLING BOATS AND
VESSELS," within that part of the United Kingdom of Great Britain and Ireland
called England, the Dominion of Wales and Town of Berwick-upon-Tweed,
and His Majesty's Colonies and Plantations abroad, in such manner as to me,
my exors, admors, and assigns, shall seem meet, and that I, my exors, adiñors,
and assigns, should enjoy the benefit and advantage from time to time accruing
and arising by reason of the said advantage for the term therein mentioned,
to hold and enjoy the said licence, privileges, powers, and advantages thercin-
before granted unto me, the said John Martin Hanchett, my exors, adñors,
and assigns, for and during the term of fourteen years from the date thereof;
in which said Letters Patent there is contained a proviso, that if I, the said

page_text: John Martin Hanchett, should not particularly describe and ascertain the nature
of my said Invention, and in what manner the same is to be performed, by
instrument under my hand and seal, and 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 Letters Patent, that then the said Letters
Patent should be void.
NOW KNOW YE, that in compliance with the said proviso, I, the said John
Martin Hanchett, do hereby declare, that the nature of my said Invention, and
the manner in which the same is to be performed, are particularly described
and ascertained by the following Specification in writing, that is to say:-
My Invention consists in the manner of applying certain pipes, which I shall
herein-after more particularly describe, to boats and vessels of any description,
whenever such boats or vessels are to be propelled or moved forward by the
reacting force produced by water being made to flow through the said pipes.
Pipes which have heretofore been used for a similar purpose have been applied
to the underside of the boat or vessel; whereas I place them in the inside, upon
or above the bottom of the boat or vessel to be propelled, as herein-before
⚫ mentioned.
.
I shall now describe the manner in which my said Invention is to be
performed (that is to say):-I employ one or more steam engines or other
first mover or movers (but I prefer steam engines) to work one or more pumps,
and I place the s* steam engine or engines and the said pump or pumps in the
inside of the boat or vessel to be propelled thereby, and I cause the same to
fixed in the usual manner of fixing such machinery on board of steam boats,
and as near to the bottom of the said boat or vessel as is found practicable,
and I place the said steam engine or engines, first mover or movers, together
with the said pump or pumps and pipes, in such a situation relatively to the
sides and ends of the said boat or vessel as shall cause the said boat or vessel,
when without any other load, to swim upright and upon an even keel. Further,
I declare that I make use of either single or double acting pumps; but as both the
single and double acting pumps are well known, and the manner of making the
same well understood, I need not be more particular in describing them, further
than what is required to explain how I employ them in procuring the requisite
force by which the boat or vessel to which or in which they are applied may
be impelled forward, which is as follows; and for the sake of perspecuity and
more easy explanation I will suppose one steam engine only to be employed
for working one pump, and that the pump stands in an upright position, so
that when at work its piston should move upwards and downwards alternately :-
The construction of the aforesaid pump will be clearly understood, by stating

page_text: that I make the piston without any valve in it, and that I apply two valves at
the bottom of the pump below the working part of the barrel, one of which
barrels opens inwards and the other outwards, in such a manner that when-
ever the piston ascends the first-mentioned valve would open, whilst the
other valve would be closed, and, on the contrary, whenever the piston
descended the first-mentioned valve would close, and the other would be opened.
To the bottom of the aforesaid pump I connect two pipes, which for the sake
of distinction I shall call the entrance and exit pipes. I make the entrance
pipe of such a length as is equal to the distance between the aforesaid pump
and the head of the boat or vessel; and I make the end of the said entrance
pipe to pass through the head of the vessel below the water line, taking care
by caulking or otherwise securing the aperture in the head of the vessel through
which the end of the said pipe passes to prevent the water entering the vessel
excepting through the said pipe, and I affix the other end of the said entrance
pipe to the bottom of the aforesaid pump by any of the well-known methods,
such as a spigot and faucet joint, or a flanch with screws, &c. &c., and in such a
manner that the said end of the entrance pipe shall be opposed to the aperture
at the bottom of the said pump, which is covered by the valve opening inwards.
In a similar manner I affix one end of the exit pipe to the bottom of the
said pump on the opposite side thereof, or on the side of the pump towards the
stern of the vessel, so that the said end of the exit pipe shall be opposed to the
aperture covered by the before-mentioned valve, which opens outwards; and I
make the exit pipe extend from the bottom of the said pump to the stern of
the vessel, and through the said stern below the water line. By below the
waterline I mean it to be understood that when the boat or vessel to which
such an apparatus is applied is afloat the outer ends of the entrance and exit
pipes should be under water. I would here observe, that the outer end of the
entrance pipe in particular ought to pass through the head of the vessel at such
a depth as will insure its being under water at all times, and if the vessel is
intended to go to sea I would turn the outer end of the entrance pipe down-
wards, and make it pass through the bottom of the vessel, so that whenever the
violence of the wind and the motion of the sen occasioned the vessel to pitch
the said outer end of the entrance pipe might be in the situation the least
liable under any circumstances to be above the surface of the water.
As a steam engine, a pump with its valves and other apparatus herein-before
described, as also the manner of constructing, combining, and applying the same,
are things already in use, and well understood by every machanic competently
skilled in the business of an engineer, it is not necessary for me to enter into a
more detailed description thereof. I shall therefore proceed to explain the

page_text: operation and effect of such an apparatus when put into motion. I will suppose the
motion of the steam engine to commence when the piston of the afore-mentioned
pump is at the bottom. In that case the said piston would be drawn from the
bottom to the top of the pump; and as the entrance pipe forms a communication
between the inside of the pump and the water on the outside of the boat or
vessel, and as the ascent of the piston would have a tendency to make a vacuum
in that part of the pump below the piston, the water would, by the weight of
the atmosphere, be forced through the entrance pipe, and the valve at the inner
end of the pipe opening inwards would allow the water to enter into and fill
the pump. The piston, having risen to the top, would begin to descend, and
in doing so would be forced down upon the water which now filled the pump;
the water, being thus compressed, would occasion the last-mentioned valve to
close, but the other valve, opening outwards, would yield to the pressure by
opening, and allow of the water to make its escape through the exit pipe; and
thus the piston, having compleated its descent, and having driven out all the
water, would again begin to rise; the valve on the end of the exit pipe would
close, whilst that on the end of the entrance pipe would again open, and so on
the pump would continue to be alternately filled and emptied by the continued
ascent and descent of the piston.
Having thus described the operation, I shall next endeavour to explain its
effect; that is, how such an operation produce a force sufficient to impel the
boat or vessel forward. The water in the pump becomes compressed when the
piston begins to descend; it follows, therefore, that the whole of the inside surface
of the pump, within which the water is inclosed, will have to resist a pressure
equal to the compressing force occasioned by the descent of the piston; but as
the valve at the inner end of the exit pipe is made to open outwards it yields
to the pressure, and permits the water to escape, consequently the pressure is
removed from the area of the opening covered by the said valve, and as this
valve is on the side of the pump towards the stern of the vessel, there will be a
less quantity of pressure against that side of the pump towards the stern than
on that towards the head of the vessel; it follows, therefore, that during the
descent of the piston the boat or vessel will be impelled forward. I further
declare, that although I have herein-before stated that I employ a steam
engine or steam engines or other first mover or movers, in conjunction with a
pump or pumps, the said pump or pumps having valves and pipes connected
therewith for the purpose herein-before mentioned, namely, that of propelling
boats or other vessels, I make no claim to any of these individually or con-
junctively, when used for the purpose herein before mentioned, the same having
been heretofore known and practised.

page_text: And, lastly, I do declare that my Invention consists solely in placing the
pipes, which I have herein-before named the exit and entrance pipes, on the
inside of and above the bottom of the boat or other vessel to which these are
applied, and thereby placing the said pipes in a more accessible and secure
situation.
In witness whereof, I, the said John Martin Hanchett, have hereunto set
hand and seal, this Twenty-sixth day of September, One thousand
eight hundred and twenty-three.
my
JOHN MARTIN (L.s.) HANCHETT.
JOHN MARTIN (L.s.) HANCHETT.