A METHOD OF CONVEYING BOATS OR BARGES FROM A HIGHER LEVEL TO A LOWER, AND VICE VERSA, ON CANALS, BY THE IMMERSION OF A PLUNGER OR PLUNGERS
Year: 1800

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, LAWSON
HUDLESTON, of Shaftesbury, in the County of Dorset, Esquire, send greeting.
WHEREAS His present Majesty King George the Third, by His Letters
Patent under the Great Seal of Great Britain, bearing date at Westminster,
the Thirtieth day of December now last past, hath given and granted unto me,
the said Lawson Hudlestone, my executors, administrators, and assigns, full
power, sole privilege and authority, to make, use, exercise, and vend, within
England, Wales, and the Town of Berwick-upon-Tweed, during the term of
years therein expressed, my Invention of "A METHOD OF CONVEYING BOATS
OR BARGES FROM A HIGHER LEVEL TO A LOWER, AND VICE VERSA, ON CANALS, BY
THE IMMERSION OF A PLUNGER OR PLUNGERS;" in which said Letters Patent is
contained a proviso obliging me, the said Lawson Hudleston, by an instru-
ment in writing 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
performed, to be inrolled in His Majesty's High Court of Chancery within
one calendar month next after the date of the said recited Letters Patent, as
in and by the same, relation being thereunto had, may more fully and at large
appear..

page_text: NOW KNOW YE, that I, the said Lawson Hudleston, in compliance with
the said proviso, do hereby declare that the nature of my said Invention, and
the manner in which the same is to be performed, is described as herein-after
followeth, videlicet :-
I assume and propose that in order to put in practice such my "Method of
Conveying Boats or Barges from a Higher Level to a Lower, and vice versa, on
Canals, by the Immersion of a Plunger or Plungers" there shall be, or be
supposed, a lock (constructed of the usual and proper materials with which locks
or canals are usually or may be conveniently made to contain water) of a proper
and convenient forni and dimension, placed in a line between and connecting
together the upper and lower parts of a canal and navigation, and furuished
at each end with a gate or sluice sufficiently wide to allow, when opened, the
passage of the boat or vessel about to be conveyed; such gates or sluices tobe
adapted in their respective depths the one to the upper the other to the lower
level of the canal or navigation. The upper part or coping of such lock must be
made of a height sufficient to contain the water of the upper line, and the bottom
of such lock must be of a depth to correspond with that of the lower line of
navigation. The horizontal superfices or form of the boat or barge intended
to be conveyed ought to correspond with that of the lock, with the allowance
of sufficient space for the free rise and fall of the vessel within the sides and
bounds of the lock, the depth of such boat being necessarily regulated by that
of the navigation. I next propose that there be a reservoir, building, or exca-
vation made (and prepared with stone, brick, wood, or any other proper material
capable of containing water) the upper part or coping of which should be at
least equal with the level of that of the said lock, and that the area of the said
reservoir shall be equal to (or rather in practice somewhat exceeding) the area
of the said lock. In this case the perpendicular depth of the reservoir should
be equal to double the intended rise or fall of the vessel within the lock, but
when the areas of the lock and reservoir are unequal this proportion varies;
for as in all cases the quantity of water to be displaced out of the reservoir
iato the lock must be equal in cubical content to that of the space in the lock
between the surface of the lower line and that of the upper, it follows that if
the area of the reservoir be greater than that of the lock, the necessary depth
of the water to be displaced will be so much the less than in the case before
stated; and e contra, if the area of the reservoir be less than that of the lock,
the necessary depth of the water to be displaced will be so much the greater,
so that when this proportional quantity of water shall be obtained by the
greater depth or by the greater area of the reservoir containing it, is a point
for the consideration of the artist. A communication sufficient for the free

page_text: passage of water at or near the bottoms or in the lower parts of such lock
and reservoir is in all cases essentially necessary. The distance between the
lock and reservoir (or reservoirs, where more than one) is discretional, provided
there be such level and communication. The shape of the reservoir is also
discretional, though, for the better adaptation of the plunger or plungers, here-
after to be described. I regard an angular form as the most convenient; and to
obviate the possibility of damage or obstruction to the free motion of the
plunger by the falling of stones or other substances between the sides of the
reservoir and the plunger, it may be practically expedient to give to the plunger or
plungers a shape somewhat diminishing downwards, in the nature of a reversed
pyramid, in order to enable the plunger or plungers, on ascending, to clear
themselves from the obstructing substance. Assuming the said lock and
reservoir to be formed to communicate as aforesaid, and to be supplied with
water from the lower line, whence of course it would follow that, whatever
might be the depth of the reservoir, the water contained in it, and the water
of the lock, and that of such lower line would have one common level; sup-
posing a vessel floated into such lock, the lower gate or sluice closed, and that
some solid body or bodies, equal or nearly so in cubical content with that of
the reservoir itself, be plunged downwards (whether falling by superior specific
gravity to that of water or forced by mechanical means) to the lower part or
bottom of such reservoir, it is obvious that the water in such reservoir (if not
all yet nearly so) would thereby be displaced, and by passing into the lock
would (in addition to the water therein-before contained) fill or nearly fill the
said lock, and the small quantity of water remaining in the reservoir would
surround the immersed body or bodies up to a level with the water in the lock;
and if such solid body or bodies were withdrawn from such reservoir, then
the water of the lock would subside to its original level, re-occupying the
space in the reservoir lately held by the body or bodies now raised and before
immersed, which I call a plunger or plungers. My said Invention there-
fore consists in the practical application of the two following laws of hydro-
statics for the purposes of conveying boats and barges from a higher level
to a lower, and vice versa,-1st, that two columns of water, however different
in lateral dimensions, will, if there be a communication between them, always
maintain one and the same level; and, 2nd, that the immersion of any
solid body in water will displace a portion of the fluid equal in quantity to the
bulk or solid contents of the body immersed (and to obviate any objection to
the application of the term "solid," as above, I would be understood as using
it hypothetically only, being well aware that in order to produce the proposed
effect by immersion, it is not necessary that the body immersed should be a

page_text: solid body); therefore I apply to the reservoir above predicated (and to more
reservoirs than one where necessary, and in any position relative to the lock,
so as the locks and reservoirs have such levels, capacities, convenient forms, and
communications as above described) one or more plunger or plungers fitted
to and nearly filling such reservoir or reservoirs, and freely moving up and
down therein (but not water-tight, nor acting as pistons or forcers, in the
common acceptation of such terms) formed of such materials, (be they stone,
wood, brick, copper, iron, or any other suitable material, or combination of
materials) as may be most conveniently applied to and used in such reservoir
or reservoirs. The means of raising or depressing such plunger or plungers,
whether by levers, balancing weights, ropes, chains, pullies, tooth and pinion,
rack wheel, capstern, windlass, winch, crank, screw, animal force, steam or other
engine or engines, or other mechanical or statical contrivances, must, according
to situations, circumstances, and expediency, be left to the choice of the person
or persons applying such plunger or plungers. My said Invention may also be
executed by causing one or more such plunger or plungers, in respect to height and
solid content, to descend or rise within the area of a lock capable of containing
(with the allowance of free motion up and down) both the proposed boat or
vessel and the proposed plunger or plungers, and of a depth or depths adapted
in its several parts to the proposed rise and fall of each of them respectively,
such plunger or plungers being also understood to be of such a figure or
figures as to permit the said boat or vessel to ascend and descend freely within
the said lock and alongside of the said plunger or plungers. But considering, as
I do at present, a partition between the plunger or plungers and the lock as
inore eligible, I notice such an application of my said method principally with
a view to prevent an evasion. My present model consists of a lock and boat
as already described (saving a certain excess in the depth of each of them), a
reservoir ucar to and paralel with such lock, oblong and rectangular, a sub-
communication as specified, a single plunger, oblong and rectangular, fitting
and (subject to free motion) filling such reservoir, having two large guiding
wheels or pullies raised by two corresponding wheels secured upon a windlass
or axis by means of lines (representing chains) fastened to such windlass
wheels, and passing under and round the said plunger. wheels, the ends of
such lines or chains being brought up and fastened to a beam and frame
supported on the space or partition dividing the reservoir and lock, which
frame and the upper part of the windlass wheels have an elevation suffi-
cient to allow of the ascent of the plunger till raised above the surface water
of the reservoir. The plunger is counterbalanced by a weight suspended by a
line representing a rope or chain fixed to the extremity of a curved or spiral

page_text: lever (I so term it, though perhaps not with strict propriety, but as its action
is analagous with that of the spiral fusec of a time piece), which lever proceeds
from the windlass axis, so that whilst the plunger is rising from its lowest
depth to its greatest height, videlicet, to the surface of the water in the
reservoir, the said curved lever, by removing the balancing weight from the
axis of the windlass in a ratio corresponding with or counteracting the in-
creasing weight of the plunger, facilitates and promotes the steady raising of
the plunger; and when the plunger is to be depressed, by reversing the action
of the windlass, the weight is made to approach the axis of the windlass, and
following the curve of the lever, it surrenders its counteracting power in
proportion or nearly so to the increase of the action of the displaced water
upon the lower surface of the plunger as depressed into the reservoir.
Premising that I consider my said method as preferably applicable where the
lifts or descents are small or moderate, yet without suggesting precise limits,
which practice only can regulate, premising also, that boats of a moderate
size, as recommended by Dr. Anderson and Mr. Fulton, and exceeding rather
in depth than in length or breadth, scem best adapted to the mode of con-
veyance proposed, I proceed to describe the manner in which, under these
contrivances, the conveying of boats or barges is effected by means of this
Invention. Let us suppose the reservoir to be sixteen feet deep, and by means
of the communication with the water in the lock and lower canal to be half full
of water; let us suppose the plunger raised to its greatest height of sus-
pension, and to be at or above the surface of the water in the reservoir;
let a boat or barge be floated through the lower sluice or gate into the lock,
the lower sluice or gate being closed and the upper one remaining so, let the
plunger be depressed to the bottom of the reservoir, the water of the reservoir
(minus the small quantity encompassing the plunger) is displaced into the lock
through the passage of sub-communication, and the surface of the water in the
lock is raised as much as the plunger sinks, videlicet, eight feet, which brings
the water in the lock upon a level with that of the upper line of navigation.
The upper gate or sluice may then be opened, and the boat floated out of
the lock into the upper canal or line of navigation. For descending con-
veyance, the lock gates, reservoir, and plunger remaining, or being put
into the present supposed state, let a boat or barge be floated into the
lock from the upper canal or line, the upper gate or sluice being closed and
the plunger raised, the water in the lock will fall as the water in the reservoir
takes place of the plunger; and when the plunger is wholly raised, the vessel in
the lock will have descended as many feet (videlicet, eight or nearly so), as the
plunger has ascended, and the boat or barge will be lowered to the water level

page_text: or nearly so of the lower line of navigation or canal; and is ready to proceed
along such lower line on the opening of the lower gate or sluice, the lock re-
maining in a situation to receive another vessel from the lower line to be raised
to the upper line in the course already described. It may be proper to observe,
that in all cases it is necessary to give to the reservoirs an equal height with the
lock, and to the plunger or plungers dimensions nearly equal to the capacity
of the reservoir. This method of conveying boats or barges from line to line,
wherever it is expedient to be practiced, seems, on a comparison with other
contrivances of late invention, to be attended with the following material
advantages:
1st, the only machinery essentially necessary (the two sluices excepted)
is for the purpose of raising or depressing the plunger or plungers.
2nd, whilst the machinery in other contrivances above alluded to is either
wholly or in part liable to injury from water, the machinery in this (the two
sluices excepted) is wholly exempt from such disadvantage.
3rd, whilst in the other contrivances the caissons, coffers, &c. require not
only the opening of one or more sluices, but also an adjustment of their ends to
the mouth of the canal, to prevent the loss of water, before each boat can enter
the lock, according to this plan, on the opening of a single sluice the boat floats
at once into the lock without loss of water or any such delay or difficulty.
When I say
"without loss of water," it must be understood with this allow-
ance, that if a beat goes down laden, and returns (or another goes up) unladen,
the upper level gains a body of water equal to the weight of the cargo, and
e contra, the lower canal gains similarly if a boat goes down unladen and
returns laden.
4th, by the application of this method to the common gate lock, or by
forming the lock of this Invention for the escape of water from the higher
level into the lock, and from the lock into the lower level, the properties and
uses of the common gate lock and of this Invention are united, and they may
be used either in combination with other contrivances or independently; so
that,
5th, whenever the water in the upper line is in plenty sufficient to allow
of a transmission of a lock full of water to the lower level, the machinery
of this Invention may be left at rest, and vessels may pass and repass by the
operation of the common lock; whereas in other Inventions above alluded to
no boat or vessel can pass or repass without working the machinery, though
the water be ever so abundant.
6th, and under the supposition that the lock used in this Invention is
constructed as the common gate lock for the transmission of water, this further

page_text: and important advantage arises, that should the machinery of the plungers or
plunger be at any time disordered, boats may still pass and repass as through
the common gate lock; whereas should any accident embarrass the machinery
of the other locks before alluded to, the whole navigation is obstructed.
In witness whereof, I, the said Lawson Hudleston, have hereunto set
hand and seal, this Twenty-third day of January, in the year of
our Lord One thousand eight hundred and one.
my
Sealed and delivered in the presence of
RICH
MESSITER,
Attorney, Shaston, Dorset.
СНА" ТНІСЕ,
Clerk to said Mr. Messiter.
AND BE IT REMEMBERED, that on the Twenty-third day of January,
in the forty-first year of the reign of His Majesty King George the Third,
the said Lawson Hudleston came before our said Lord the King in His
Chancery, and acknowledged the Instrument aforesaid, and all and every thing
therein contained and specified, in form above written. And also the Instru-
ment aforesaid was stamped according to the tenor of the several Statutes
made in the sixth year of the reign of the late King and Queen William
and Mary of England, and so forth, and in the seventeenth, twenty-third, and
thirty-seventh years of the reign of His present Majesty King George the
Third.
11
عمل
the va
of our Lord One