CERTAIN IMPROVEMENTS APPLICABLE TO INLAND NAVIGATION, WHICH IMPROVEMENTS, OR PARTS THEREOF, ARE APPLICABLE GENERALLY TO RAISING, LOWERING, OR TRANSPORTING HEAVY. BODIES
Year: 1850

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
WATT, of the City of Glasgow, North Britain, Manufacturing Cheinist, send
greeting.
WHEREAS Her present most Excellent Majesty Queen Victoria, by Her.
Royal Letters Patent, under the Great Seal of the United Kingdom of Great
Britain and Ireland, bearing date at Westminster, the Fifth day of Sep-
tember, in the fourteenth year of Her reign, did, for Herself, Her heirs
and successors, give and grant unto me, the said William Watt, Her especial
license, full power, sole privilege and authority, that I, the said William Watt,
my exors, adiiors, and assignes, and such others as I the said William
Watt, my exors, adiñors, or assignes, should at any time agree with, and no
others, from time to time and at all times during the term of years herein
expressed, should and lawfully might make, usc, exercise, and vend, within
England, Wales, and the Town of Berwick-upon-Tweed, within the Islands of
Jersey, Guernsey, Alderney, Sark, and Man, and also within all Her Majesty's.
Colonies and Plantations abroad, my Invention of "CERTAIN IMPROVEMENTS
APPLICABLE TO INLAND NAVIGATION, WHICH IMPROVEMENTS, OR PARTS THEREOF, ARE
APPLICABLE GENERALLY TO RAISING, LOWERING, OR TRANSPORTING HEAVY.
BODIES;" in which said Letters Patent is contained a proviso, requiring that I,
the said William Watt, by an instrument in writing under my hand and seal,
shall particularly describe and ascertain the nature of my said Invention, and
in what manner the same is to be performed, and shall cause the same to be
enrolled 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.

page_text: NOW KNOW, that in compnance with the said proviso, 19
LUC
William Watt, do hereby declare the nature of my Invention, and in what
manner the same is to be performed, to be particularly described and ascer-
tained in and by this present instrument in writing, as follows, reference being
had to the Drawings hereunto attached, and to the letters and figures marked
thereon; that is to say,
My said Invention relates,-
First, to certain novel arrangements of mechanism, apparatus, or means
applicable to inland navigation, whereby the passage of boats and vessels
through the locks of canals or watercourses, or the navigable communication
between the upper and lower levels of such canals or watercourses, is effected
with greater facility and economy of water than at present, by the use of com-
pressed air or other gascous body, or the adoption of the principle of exhaustion
for the elevation and depression of the water levels, as may be required.
Second, to arrangements of apparatus or means to be used for the per-
formance of lifting, lowering, and transporting operations in various situations,
such as in rivers and harbours, to facilitate the loading and discharging of
vessels and other floating bodies, and for raising excavated materials for deposit
ōn the banks.
Third, to arrangements of apparatus or means applicable to graving and
other docks for the elevation of vessels and other floating bodies therein.
Fourth, to the application of compressed air or other suitable gaseous body
to the holds, or interiors of vessscls for the prevention of the sinking of such
vessels from leakage.
And in order that the object of my said Invention may be properly under-
stood, I shall now proceed to describe the several Figures on the Sheets of
Drawings hereunto attached. Figure 1, on Sheet 1˚ of my Drawings, is a
complete longitudinal sectional elevation of a portion of a canal or watercourse,
shewing a part of the lower water level, two lock chambers, and an inter-
mediate basin, as fitted or arranged to be worked according to my improve-
ments; Figure 2 is a plan of the same, corresponding; Figure 3 is a trans-
verse vertical section across the canal at the line a, b, in the plan, Figure 2,
representing the lowest pair of gates of the series in elevation, looking upon
the inner side of the gates, or in the direction of the rise of the canal; and
Figure 4 is a transverse vertical section across the intermediate chamber at
the line c, d, in the plan, looking on the exterior of the higher pair of gates, or
in the direction of the fall of the canal. The general details of the locks are
similar to those of ordinary locks as at present constructed, and the two which
I have represented are to be considered either as the whole or as a portion of

page_text: a series on an existing canal, modified according to my improvements. The
natural level of the lowest section of the canal is at A, terminating in the
contracted lock entrance B, of the width of the lock chamber, from which it is
separated by the lowest pair of gates C. The lock chamber D is similarly
fitted at its opposite end with the short pair of gates E, opening into the
intermediate basin F, or into the natural higher level of the canal where a
single lock only is used. The next higher lock chamber G is precisely similar
in construction, and is fitted with the lower and higher pairs of gates H and
I, the latter opening into the next level section J of the canal. The action of
raising and lowering boats in ordinary locks by the discharge of water through
sluice gates is well understood by practical men, and I shall only herė refer to
it for the purpose of explaining that instead of such discharge and consequent
loss of water, I accomplish the necessary raising and lowering movements by
means of compressed air, which is employed to elevate the water level in the
lock chambers. A tank or receiver K, L, of a capacity somewhat more than
is sufficient to raise the water level A the full height of the lift, is laid down
by the side of each chamber throughout the series, its level being at or near
the lower level of the canal. A line of pipes M is laid down by the side of
the locks, and in communication with each receiver by valves at N, O;
this line of pipes or air main is in communication with a compressed air
receiver, which is supplied with air by a blowing cylinder or any other
convenient apparatus driven by a suitable prime mover. Where water power.
is attainable, a water wheel may be employed for this purpose, or a steam
engine may be used; a small engine. being sufficient to work a long range of
locks. In my Drawings it may be supposed that the compressed air enters
the main at P, where a stop-cock or valve Q governs its admission. When it
is intended to pass a vessel up the locks to the higher canal level, it is entered
into the lowest chamber D, both gates being shut upon it in the usual way.
The valve N is then opened to admit compressed air to act on the surface of the
water contained in the full receiver K. This receiver communicates with the
bottom of the lock chamber D, by the pipe R, opening out from the bottom of
the receiver, so that when the water in the receiver is displaced by the entrance
of the air, it passes into the lock chamber, thus elevating the level within
it to that of the basin F, when the valve N is closed, and the upper gates E
being opened, the vessel is passed onwards to enter the remaining locks. The
expanded side of the basin F admits of two or more boats abreast, so that if
another boat is passing in the opposite direction, or down the locks, it may at
once enter by the open gates E, and pass into the lock which the first-
mentioned boat has just quitted. In such a case, when the ascending and

page_text: descending boats are shut into their respective chambers G and D, a communi-
cation is formed between the two receivers K and L, by opening the valve S in
the connecting pipe T. When this is done, as the receiver K is charged with
compressed air, the result is that the elastic force of the latter acting upon the
surface of the water contained in the full receiver L, displaces the water
therein, and forces it through the pipe U into the higher lock chamber G.
This displacement goes on until the pressure in each receiver is the same,
when the water level in the lower chamber D will have fallen about half way
down, and that in the higher chamber G will have risen from the natural
level V of the basin F to the same distance. This brings each boat to about
midway in each chamber, that is, the descending boat in the chamber D will
be half way down its lock on the downward journey, and the ascending boat
will be half way up on its upward journey.. The air discharge valve W is now
opened to discharge the remaining air from the receiver K, and as this allows
the water in the chamber D to flow back into its receiver, the water in the
chamber is brought down to the original level A, and the gates C being opened
the boat is passed out and along the canal. But the vessel in the upper
chamber G has still to be elevated throughout its remaining half rise, and this
is accomplished by a supply of compressed air from the main M, the valve O
being opened for this purpose. As the water is already half displaced from
the receiver L, it is obvious that only one half the quantity of air originally
used in the lower receiver will be necessary to displace the remaining water in
the higher receiver L, and elevate the level in the chamber G to the level J,
when the gates I are opened, and the ascending bont is passed onwards. The
higher lock is thus left full and the lower one empty, in readiness for the cor
responding ascent and descent of succeeding boats. The upper chamber G
may be worked in concert with the next higher lock, as already described
with reference to the lowest pair of the series, an air discharge valve Y being
fitted to the receiver L to answer the same purpose as the corresponding
valve W on the lower receiver K. The receivers K and L are placed with
their upper surfaces on a level with the natural level A of the water in the
canal and that of the intermediate basin V respectively, so that except, when
charged with compressed air, they are both full of water, and at each move-
ment they are refilled with the same water which has been discharged by the
air pressure. The arrangement of pipes which I have delineated in my
Drawings is such as would answer. for working a long series or chain of
locks, the main M being run alongside the whole line and made to com-
municate with the receiver at each chamber, whilst the second main or con-
necting pipe T is employed simply as a connection between each pair of

page_text: receivers, a similar pipe H being passed onwards from the receiver L to the
next higher one in the chain. By this plan the continuous main M is
kept constantly charged with air, so that whilst each pair of receivers
may be put into connection by the intermediate main T, for the purposo
of economising the expenditure of air, as already described in reference to the
simultaneous passage of ascending and descending boats, the communication
throughout the compressed air main M is kept free and uninterrupted, to
admit of the air pressure being conveyed to any single receiver throughout the
entire chain of locks to carry up or down any single boat. In situations whero
there are only two locks working in connection, as delineated in my Sheet of
Drawings, then the intermediate main T may be dispensed with, as the air
pressure not being required to proceed further than the second receiver L, it
may be employed when necessary-to form the air communication between the
two receivers K, L. It will be readily understood how this can be acconi-
plished by a suitable working of the set of receiver valves. In simultaneously
passing a boat each way up and down a single pair of locks by the use of 'tho
single line of pipes only, the water in the lower lock is first clevated in the
manner already described by the admission of the air pressure to the receiver
through the valve N. The stop valve Q is then closed to shut off the air
supply, and the ascending boat being passed from the lower to the higher
chamber, and the descending one from the higher to the lower chamber, the
inlet air valve O of the upper receiver L is opened to put the two receivers in
communication by the main M. This communication, as before described,
depresses the water level in the lower chamber, and elevatos that in the higher
chamber, and the remaining air in the lower receiver K being discharged by
the valve N, the water in its corresponding chamber is lowered to the level A.
and the descending boat is passed out of the chamber. The stop valve Q is
now opened, and a further supply of compressed air is thus blown into the
upper receiver to complete the elevation of the water in its corresponding lock
chamber. In my Drawings I have represented the receivers K and L as
placed parallel with their corresponding lock chambers, which position neces-
sitates their being sunk beneath the surface of the earth, except in situations
where, by carrying out the connecting pipes R, U, and the receivers to
some distance, the carth's surface will admit, of the latter being placed at tho
required level, without involving any excavation. By another arrangement all
excavation may in most cases be avoided. This may be accomplished by
placing each receiver alongside the level of the canal at the foot of its corre-
sponding lock chamber. Thus, in reference to my Drawings, the receiver L
would be placed alongside the intermediate basin F, and the receiver K along.

page_text: side the lower level A, to get beyond the elevation of the chambers. I have
represented the receivers as formed of cast-iron plates, but various materials
and modes of construction may be adopted'; and by a suitable preparation of
the earth surface beneath, with asphalte or other water-tight covering, the
bottoms of the receivers themselves may be dispensed with. The various
actuating valves may be worked by levers or screw handles, as is well under-
stood; and such of them as may require to be moved simultaneously may be
connected in any convenient manner for that purpose. Although I have
described this system of locks as being worked by compressed air, pumped or
otherwise forced into the receivers, it is yet evident that the same practical
result may be effected by the adoption of the principle of exhaustion.
Figures 1, 2, and 3, on Sheet II. of my Drawings, represent three views
of my arrangement, whereby I propose to employ the power of compressed
air, upon the principle which I have already explained in reference to canal
locks, for loading or discharging vessels in harbours, canals, rivers, and
similar situations, and for raising and lowering floating bodies generally. As
an example of the action of the apparatus, I have delineated it as applied
for raising loaded punts of earth waggons from the water level of a river or
harbour to the height necessary for the disembarkation of the waggons from
their supporting punt to the wharf or pier head. Figure 1 is a front elevation
of the elevating machinery on the water side, the sluice gate being represented
as closed down; Figure 2 is a corresponding side elevation of the same, as
moored alongside the wharf; and Figure 3 is a ground plan, complete.
Immediately in front and close up to the, wharf or river wall A, a hollow
rectangular air and water-tight receiver B, made of boiler plate, is moored
or imbedded upon the river's bottom, so as to be immoveable. On the top of
this vessel is erected a rectangular open-topped chamber C, also of boiler plate.
This chamber or receiver is fitted with a front sluice gate D on the river side
for the entrance and exit of the punts, and it is carried up to such a height as
may be necessary to carry a water level of sufficient elevation to float the punts
to the level where the waggons thereon may be run off on to the pier head.
The front end E of the chamber C is of cast iron bolted or rivetted on to
the edges of the side plates by angle irons at F, F. The lower portion of this
end is open to form the entrance for the punts, and this entrance is guided by
the sluice gate D, which is arranged to slide vertically upon suitable plane
faces on the interior surface of the end E, as represented by the dotted lines in
Figure 1. The weight of this gate is counterbalanced by the two weights G,
suspended from chains passing over fixed pulleys H supported in brackets
carried by the stationary end E, which chains are finally attached to eyes at.

page_text: I, near the bottom edge of the gate. A platform J is carried along the two
sides of the chamber near the top to carry the attendants for working the
apparatus. The raising and lowering of the gate is effected by the two winch
handles K on opposite ends of the horizontal shaft L, carried in bearings in
the two end brackets M, bolted to the end E of the chamber. This shaft
carries a toothed pinion gearing with the rack N attached at O near the
bottom of the gate, which may be fixed at any point of its vertical travel by a
detent P hinged in front of the rack, into the teeth of which it is set to gear
when necessary.
The bottom receiver B is completely closed in and has no
internal communication whatever with the water which surrounds it, and it is
in communication with the upper chamber C only by the wide pipe or water-
way Q. This pipe is open at both ends, and extends downwards from the
bottom of the chamber C to the level of the bottom of the receiver B, which is
recessed at R to allow of a waterway beneath its edges. The compressed air.
magazine or large receiver may be placed in any convenient position alongsido
the wharf on shore, being supplied with air by a pump or blowing engine driven
by a small steam engine or any other available power. The air is conducted.
from the magazine by the pipe S, terminating in the branch T'on the top
of the vertical pipe U opening at its lower end into the top of the receiver B.
In my Drawings I have represented a punt in two different positions, one
at V in the river outside the lifting chamber, and another W as in process of
elevation in the chamber, the side of which is broken away to permit it to be
seen clearly. The natural level of the river is at X, and when a loaded punt
is to be elevated from this level for discharge upon the wharf, it is floated
up to the sluice gate D, and the latter being elevated for the purpose by the
machinery already described, the punt is entered into the chamber, and the
sluice is again closed. The stop valve Y on the inlet pipe is now opened to
admit the compressed air to the receiver B. This receiver is always full of
water except at the time of lifting, and is of sufficient capacity to furnish as
much water to the elevating chamber as will raise the fluid level from the
natural river level X to the height which will float the punt to the level of
discharge. Wheu the air pressure is let on to the surface of the water in the
receiver B, the water is displaced, and makes its way upwards through the
duct or waterway Q into the chamber above. The continued air pressuré
thus elevates the water level in the chamber, floating up the punt as at W,
until it reaches the required height, when the air supply is cut off by the valve
Y, and the lifting action of course ceases. The upper edge of the end of the
chamber next the wharf communicates with the latter by an inclined platform
Z, carrying double sets of rails a, b, which correspond in guage with similar

page_text: rails on the surface of the punts. The latter rails carry the earth waggons
c, c, when floating, and according to the arrangement which I have delineated,
the waggons constructed of plate iron are constructed so as to pack close
together with their adjacent edges in contact when on the punts. In raising
the earth in waggons on the punt, the axles of the wheels are so placed as
to bring the bottoms of the waggons close to the punt surface, and thus lower
the centre of gravity. The particular service for which this plan is adopted is
for receiving and carrying away the mud and earth raised by dredging ma-
chinery, as the punt with its complement of waggons being passed under the
discharge end of the dredger, the whole of the waggons are gradually filled
without any inconvenience or loss from mud being dropped either between
the waggons or upon the thick edges, which would occur with the ordinary
arrangement of wooden waggons. When the loaded punt has been elevated
to the necessary height in the chamber, the hinged detents d on the upper edge
of the chamber are thrown into gear with the recesses e on the punt, so as
to hold the latter in a fixed position. The loaded waggons are then run off
the punt along the rails a, b, and down an incline, whereon they are conveyed
to the place of discharge. The empty waggons to be sent afloat for a
fresh supply of earth from the dredger are similarly drawn up the incline
and run upon the punt as before, and the detents & being disengaged, the air
discharge valve f is opened, when the gravity of the water in the chamber
forces out the air originally blown into the receiver, the displaced water falls
and finds its way back through the channel Q into the receiver until the fluid
level in the chamber coincides with that of the river X. The sluice gate D
being now opened, the punt with its empty waggons is floated out. To econo-
mize labour, in running the empty waggons upon the punt from the pier, the
well-known rope and pulley movement may be adopted. A horizontal pulley
being set at the head of the incline, a rope is passed over it, and the loaded
descending waggons being connected to one end and the empty ascending ones
to the other, the loaded ones will draw the light ones up. Great economy in
the expenditure of compressed air may be effected in situations where two
elevating chambers may be set side by side, and worked in concert, upon
the. principle already described in reference to my mode of working a
chain of canal locks. In such a case the apparatus and arrangements
delineated in Sheet 2 of my Drawings are to be doubled in every respect, with
the addition of an air pipe of communication between the two receivers.
we then suppose a loaded punt to be at the bottom of one chamber in
readiness for making the ascent, and a light punt at the top of the other
chamber ready to descend, then the receiver connected with the latter being.
If

page_text: charged with air, whilst that of the former is full of water, it is evident that
when a communication is formed between the two receivers the water level in
the first-mentioned chamber will rise half way up, whilst that in the second
will fall correspondingly; the air and water in each being relatively displaced
or, instead of using the air pressure in such modification, hydrostatic pressure
may be employed for effecting the same purpose, or for varying the water level
in a single tank. The descending punt is then lowered entirely by a discharge
of the remaining air from its receiver, whilst the ascending one is elevated to
the top of its lift by an additional supply of compressed air, equal in quantity to
about one half of that originally used at the first full elevation of the water.
By another plan. the elevating chamber may be made double by a central
partition or division, so as to form two chambers of the dimensions requisite
for the vessel or load to be raised.
It will be clear to practical men, that this system of lifting and lowering
may be judiciously employed for a great variety of purposes. If the apparatus
is intended simply for the discharge of earth, it may be convenient to construcț
it so as to be portable or removeable to the various points where it is intended
to discharge the materials, and for this end the arrangement I have delineated
is perhaps to be preferred. Being constructed almost entirely of light boiler
plate, it will only be necessary to charge the receiver B with air, without
forcing any water into the chamber C, when the whole apparatus will become
sufficiently buoyant to be raised from its seat and floated away to another
locality. If intended as a permanently fixed elevator for goods or minerals,
the receiver and chamber may be built of cast-iron plates and securely moored.
It will be unnecessary to enter into any explanation of the application of this
plan for loading vessels, or for the conveyance of heavy bodies from the wharf
surface to a lower level, as such movements are effected by the same general
system as that which I have already described.
In Figures 1, 2, and 3, of Sheet III. of my Drawings, I have represented
my proposed plans for the employment of compressed air in a ship-lifting
apparatus. Figure 1 is a longitudinal section of a pair of elevating chambers,
supposed to be connected at the lower level with a river or harbour, and show-
ing a ship as elevated high and dry in the second or higher chamber; Figure
2 is a corresponding plan of the chambers, with their three sets of gates
complete, and the large receiver alongside; and Figure 3 is a front elevation
of the river wall, and the entrance to the chambers with the ship in situ, onc
of the entrance gates being represented as shut, the other open. In general
principle this plan is precisely similar to that which I have adopted for canal
locks; the two chambers, D, F, being similar to ordinary lock chambers,

page_text: separated only by the gate recesses. The external river level is supposed
to be at A, B, being the level of the quay wall, in which is formed the
entrance for the vessels guarded by the pair of gates C, opening from the
river towards the land, or into the lower cbamber D, which again is sepa-
rated only by the recessed space for the gates E, from the higher chamber F.
Alongside the lower chamber, and with its upper surface coincident with
the river level A, is placed a cast-iron receiver G, the bottom of which
communicates by means of the two ducts or waterways H, H, with the
bottom of the chamber. A compressed air pipe, the arrangements for
which I need not here explain further, as they are similar to those of the canal
lock and elevator previously described, opens into the top of the receiver.
When a ship is admitted into the lower chamber the oppositely arranged
gates C and E being, closed the compressed air is admitted to the top of the
receiver, and the pressure is continued until the water in it is displaced by it,
and forced by the passages H into the chamber until the water in it arrives
at the level I. The ship thus elevated is then passed onwards through the
gates E to the second chamber F, as represented in Figures 1 and 3, for
repair if necessary, the water being discharged from both chambers by letting
off the air pressure when the ship comes high and dry on an even keel on the
bottom of the chamber. Another pair of gates at J connects the second
chamber with a succeeding one if a chain of chambers is required, or the
chamber K may be expanded or extended to answer simply as a large dry
dock for the reception of several ships at one time. To save trouble in an
unnecessary removal when a ship is elevated sufficiently in the first chamber D,
she niay be received upon a cradle whilst the water is let off low enough to
permit of examination of her bottom, and if repairs are required she may then
be conducted to the inner chamber. I may remark that the actuating air
supply may be economized in the manner I have already described in reference
to Sheets I. and II. of my Drawings. The principle of economizing the
expenditure of water by the employment of compressed air is also applicable
to ordinary wet docks. In this application, advantage being taken of the
occurrence of high tides to secure the greatest depth of water in the dock,
vessels may be passed and repassed through the chamber or entrance lock,
formed in the usual way by two pairs or sets of gates by the employment of the
power of compressed air, or the exhaustion principle to elevate the water level
in the chamber in the manner herein-before described. Thus the water level
in the dock will not be affected by any loss of water by the passage of vessels
through the gates, as occurs in the ordinary way of passing vessels, and large
vessels may thus be kept constantly afloat in the dock with the greatest depth

page_text: of water attainable. at the highest tides, whilst the smaller ones may taken out
or entered into the dock at any state of the tide without the loss of any of the
dock water.
. Another branch of my improvements in raising and lowering bodies refers
to a mode of giving buoyancy to vessels which may be in danger of sinking
from leakage or other cause. In such a case I propose to keep down the
leakage by forcing air or other gaseous body into the interior of the injured
vessel's hold, or a compartment thereof, by an air pump or other suitable
apparatus placed on the vessel's deck, or in any other convenient position.
The hold, or that part of the vessel into which the air is to be forced, is to be
made air-tight, if necessary, by the application of sheet lead, india-rubber, cloth,
or other suitable covering, and air must then be forced in until an amount of
compression somewhat greater than that arising from the hydrostatic pressure
of the water. at the leak is attained. The internal air pressure will thus
counterbalance that of the external hydrostatic pressure, and prevent, or at
least mitigate, the leakage, and keep the vessel afloat.
Having now described and particularly ascertained the nature of my Inven-
tion, and the manner in which the same is or may be used or carried into
effect, I may observe, in conclusion, that I do not confine or restrict myself to
the precise details or arrangements which I have had occasion to describe or
refer to, as many variations may be made therefrom without deviating from
the principles or main features of my Invention; but what I consider to be
novel and original, and therefore claim as the Invention secured to me by the
herein-before in part recited Letters Patent, is,―
First, the system or mode of varying fluid levels in elevating or lowering
chambers or receivers employed for the transport of floating bodies, by.the
displacement of a fluid contained in a communicating chamber or chambers
through the agency of compressed air or other suitable gaseous body or bodies,
or by means of the converse action of exhaustion.
Second, the application and use of a closed chamber or chambers in com-
munication with canal lock chambers or other elevating and lowering water
chambers, for the purposes herein-before described.
Third, the application and use of compressed air or other gaseous body or
bodies, or of the principle of exhaustion, for the purpose of varying the water
level in the lock chambers of canals and watercourses, or in other similar
contrivances employed for communicating between higher and lower fluid
levels.
Fourth, the system or mode of working locks or other similar contrivances
for passing vessels from one fluid level to another by the displacement of water

page_text: contained in receivers or tanks in communication with the lock chambers, as
herein-before described.
Fifth, the system or mode of working locks and other elevating and lower-
ing chambers by placing two or more receivers in communication for the
purpose of allowing the compressed air in one to partially elevate the water
level in the other, as herein-before described.
Sixth, the application and use of compressed air, or the principle of exhaus-
tion, for loading and discharging vessels or other floating bodies or apparatus,
as herein-before described..
Seventh, the application and use of compressed air, or the principle of
exhaustion, for working graving or other docks, as herein-before described.
Eighth, the system or mode of transferring vessels or floating bodies to and
from wet docks at various levels of the water outside such docks, by the
displacement of the water in the entrance chamber or chambers, as herein-
before described.
Ninth, the system or mode of giving buoyancy to injured or leaking vessels
by the application of compressed air, to retard or stop the internal flow of
water to the interior of the vessel.
In witness whereof, I, the said William Watt, have hereunto set my
hand and seal, the Third day of March, in the year of our Lord
One thousand eight hundred and fifty-one.
Signed, scaled, and delivered in the presence of
WILLIAM JOHNSON, C. E., & Patent Agent,
Glasgow.
DAVID C. MYERS, his Clerk:
AND BE IT REMEMBERED, that on the Third day of March, in the
year of our Lord 1851, the aforesaid William Watt came before our said
Lady the Queen in Her Chancery, and acknowledged the Specification afore-
said, and all and every thing therein contained and specified, in form above
written. And also the Specification aforesaid was stamped according to the
tenor of the Statute made for that purpose.
HAAM
Land On
Enrolled the Fourth day of March, in the year of our Lord! One
thousand eight hundred and fifty-one.