CERTAIN IMPROVEMENTS IN MACHINERY OR APPARATUS FOR AFFORDING ADDITIONAL OR ARTIFICIAL BUOYANCY TO SEA-GOING AND OTHER VESSELS, AND FOR LESSENING THEIR DRAUGHT OF WATER, AND WHICH SAID IMPROVEMENTS ARE ALSO APPLICABLE TO RAISING VESSELS OR OTHER HEAVY BODIES, AND FOR SECURING OR SUPPORTING THE SAME
Year: 1843

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
WOOD, of Parkfield, Birkenhead, in the County of Chester, Merchant,
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 Fourteenth day of August, in the seventh year of Her reign,
did, for Herself, Her heirs and successors, give and grant unto me, the said
John Wood, Her especial licence, full power, sole privilege and authority, that
I, the said John Wood, my executors, administrators, and assigns, and such
others as I, the said John Wood, my executors, administrators, 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 expressed, should and lawfully might make,
use, exercise, and vend, within England and Wales, and the Town of Berwick-
upon-Tweed, and in all 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 IN MACHINERY OR APPARATUS FOR
AFFORDING ADDITIONAL OR ARTIFICIAL BUOYANCY TO SEA-GOING AND OTHER VESSELS,
AND FOR LESSENING THEIR DRAUGHT OF WATER, AND WHICH SAID IMPROVEMENTS
ARE ALSO APPLICABLE TO RAISING VESSELS OR OTHER HEAVY BODIES, AND FOR
SECURING OR SUPPORTING THE SAME;" in which said Letters Patent is contained
a proviso that I, the said John Wood, shall cause a particular description of
the nature of my said Invention, and in what manner the same is to be
performed, to be enrolled in Her Majesty's High Court of Chancery within

page_text: six calendar months next and immediately after the date of the said in part
recited Letters Patent, as in and by the same, reference being thereunto had,
will more fully and at large appear.
NOW KNOW YE, that in compliance with the said proviso, I, the said
John Wood, 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 in and by the Drawings hereto annexed, and the following
explanation thereof, that is to say :-
My improvements consist in the novel application and employment of
well-known principles and materials, and in the peculiar combination and
arrangement of apparatus adapted to the above purposes; and apply, firstly, to
sea-going or other vessels, being designed to afford additional or artificial
buoyancy or to lessen their draught of water, and may be employed either
externally or internally; secondly, my improvements apply to raising vessels
or other heavy bodies, and consist in a similar application of apparatus suitably
adapted for such purposes; and, thirdly, my improvements apply to sustaining
or securing weight, and consist also in a further application and modification
of similar apparatus suitably arranged for the purpose. The main feature of
novelty in each adaptation of my improvements is the employment and use of
common or condensed air contained in suitable apparatus, and in the convenient
application of the same to the circumstances required.
Having thus described the nature and object of my said improvements,
I proceed to show the manner in which the same are to be performed; and in
order that the several features of novelty may be well understood, I have
attached to these Presents two Sheets of Drawings, illustrating various modes
of application in which the apparatus may be employed:-
In Sheet 1 the apparatus for affording additional or artificial buoyancy to
sea-going and other vessels, or for lessening their draught of water, is exhibited
in the various Figures, and may be applied or used both externally and internally.
Firstly, I will describe its application externally, for which purpose its con-
struction is as follows, and shewn at Fig. 1, which is a vessel capable of
retaining condensed air, made of any flexible material, as india-rubber or
caoutchouc cloth, oiled silk, or cloth. Fig. 2 represents a case for the former,
made of a strong fabric of cloth, as canvas, or, if necessary, of metal or timber.
Fig. 3 represents the whole enclosed in tackle for holding of cardage, of chain,
or wire rope. I prefer for the air vessel india-rubber cloth, from its perfection
in retaining condensed air, and its elasticity and strength, which latter property,
by increasing the number or strength of the cloths, united into one substance
by means of the layers of india-rubber or varnish, may be augmented to any

page_text: required degree. For the case, canvas, oiled or otherwise, from its combining
great strength with flexibility, is preferable for general purposes. For the
tackle, cordage is generally preferable to chain, not being liable to rust nor to
injure the ship's sides, and being more suitable to the other materials when
of cloth. The shape of the air vessel may be varied, globular, cylindrical,
triangular, &, but the spherical form generally answers best, from its greater
strength, capacity, and economy of material.
Fig. 1 represents a globular air vessel of india-rubber cloth, with encircling
bands of loops; and a, a, the apertures, in which are inserted brass union joints
for connecting the air vessel with the hose, through which the air is forced
into it.
Fig. 2 represents a case of canvas to enclose the air vessel, with holes
corresponding with the loops in Fig. 1, and serving also for the free-er egress
of water. At b, b, the case divides into two parts, which are united by lacing,
or what sail makers denominate a "latchet;" at c, c, the case also opens on
one side by unlacing, which openings are for the purpose of receiving the air
vessel; d, d, are apertures, corresponding with those in Fig. 1, for the union
joints to pass through.
Fig. 3 represents the holding tackle of ropes, in size and number suitable to
the weight they are intended to bear, and crossing each other so as to act as a
sort of second case for the air vessel when inflated; the rope work itself
forming a true sphere of a sort of net-work, the cross ropes being tied or
seized at the points where they meet. At the lower part, from e round the
bottom to f, other ropes are attached, each of the latter taking hold of one of
the former, so that the strain of the weight, when lifted, may be distributed
as much as possible over the whole surface of the globular figure; the latter
ropes being intended to be united to similar ropes on a second air vessel, and
the junction of these ropes forming a sort of cradle for the ship's bottom and
sides to rest upon between the two air vessels; the air vessel case, and rope
work, are then united together by the loops or latchets. g, g, are the ropes for
making fast on deck to timber heads or any part strong enough to hold. For
the greater protection of the air vessel, the canvas case is of rather smaller
capacity than the former, and the casing of rope, again, rather smaller than
the canvas one. By this arrangement, the air vessel, however slender almost
its material, cannot burst by inflation or external pressure until the outer
canvas does so, nor the canvas again, except through the apertures of the
ropes (which may be made close enough to prevent it), until the latter give
way, whilst each rope is measured to bear its own portion of the weight
sustained, and the whole together; the aggregate weight intended to be up-

page_text: borne making allowance for the relief to the ropes by friction where they press
those that pass under the ship against the bottom, and those on each side
against the sides.
Fig. 4 represents the two air vessels with the band of rope work uniting
them. h, h, is the place of union, which may be effected by means of "clip-hooks
and thimbles," the extremities of each part may be removed, if necessary, to
shorten the band of rope work between the two air vessels, and the inner set of
hooks may be united to the corresponding thimbles, and the number of these
divisions of the band may be encreased, if necessary; i, i, is the hose made of the
same material as the air vessel, with a case of canvas and a spiral rope running
round the canvas to keep it from injury, and also to prevent the air tube or hose
inside from being so bent at any part as to prevent the passage of air through
it; for this latter object, also, a piece of cord runs through the whole length inside
the air tube, fastened inside at each end. The tube or hose may be attached to
the air vessel at either of the union joints, or both apertures may be united to
tubes, the other end of the tube or tubes communicating with the nozzle of the
air pump or bellows on deck by means of an union tube of any convenient form;
or each air vessel by its hose may communicate in succession with the bellows
or air pump. The second aperture for the insertion of hose in the air vessel
serves for the purpose of more rapidly inflating or exhausting the latter, when
necessary, or it may serve for a safety valve to indicate the degree of pressure
of the air upon the interior sides of the air vessel.
Fig. 5 represents another modification of the air vessel, of india-rubber cloth,
with the canvas case permanently united to it by means of the caoutchouc
process, so as to form of both one substance, bands with loops sewed on
(smaller than those in Fig. 1) being united by the caoutchouc process to the
outside of the canvas, the loops serving to confine the holding rope passing
through them to their proper places, which ropes, when once fitted and fastened,
may remain so, thus making only one instead of three parts, and the globular
rope work, in this instance also being of smaller capacity than the air vessel,
bears the chief strain in the first instance; or, instead of ropes encircling the air
vessel, strong canvas bands may be substituted, the latter being united to the
outside of the canvas, and at the points where they meet at the lower part of
the sphere their ends may be left pendant, and so strengthened as to allow of
the holding ropes being attached to them, and this arrangement would reduce
the apparatus to smaller bulk.
Fig. 6 represents another arrangement of the holding tackle or ropes, every
rope encircling the whole sphere, but crossing each other obliquely, and each set
of ropes converging at different points or poles, so that the cables or chains

page_text: k, k, k, fastened to the air vessel at such points, and passing under the ship's
bottom and sides, and the ends being made fast on deck, the strain or pull of
each is distributed over the surface of the air vessel. Further, the ropes
passing over and from the air vessels, by increasing their strength, may be
diminished in number, and their arrangement varied accordingly.
Fig. 7 represents two cylindrical air vessels with the ropes or chains uniting
them at 1, 1, 1, and which pass under the ship's bottom, one air vessel running
along each of her sides; 9, 9, are the ropes for making fast on deck, and i, i, the
hose for inflation. The encircling tackle may be arranged as shewn in either
of the preceding Figures. The cylindrical shape has the advantage of being
extended along three-fourths, it may be, of the ship's length, thereby more
equally distributing the pressure along the ship's side, but this advantage is
counterbalanced by the increased expense, the spherical shape being the most
capacious of any figure, and in that respect the cheaper, which is of importance
where so great surface of material is required.
Fig. 8 represents a side elevation of a ship with three paris of the air
vessels, similar to those shown in Fig. 4; a, a, the water line; b, b, the air
vessels, each pair being united by the cradle of rope work c, c; d, d, are the
holding ropes attached to the deck, and e, e, are the hose pipes in connection
with air pump or bellows on board the vessel; supposing the vessel to be
drawing sixteen feet water when loaded, and the air vessels each to be fourteen
feet diameter when inflated and immersed, each air vessel will displace about
forty tons weight of water, and the six together two hundred and forty tons
weight; and being firmly attached to the ship, by their upward pressure
they lighten her weight by nearly so much, and her draft of water pro-
portionably.
Fig. 9 represents a portion of a ship with one pair of air vessels similar to
those shown in Fig. 6, supposing the ship to be drawing twenty-two feet
water; a, a, being the water line, and suppose the diameter of each air vessel
to be twenty feet immersed and inflated, they will displace together also about
two hundred and fifty tons weight of water, lightening the ship's weight and
her draught of water proportionably; b, b, are the ropes extending from the
corresponding air vessel on the other side of the ship.
Fig 10 represents the manner in which the ropes attached to each air vessel,
as used in Fig. 9, cross each other under the ship's bottom, forming for her
a sort of cradle, which prevents the ship being strained by this mode of raising
her as effectually as in Fig. 8; the vessel in this Figure is necessarily shewn
reversed.
Fig. 11 represents a portion of a ship with an air vessel attached at the

page_text: bow, corresponding with another attached at the stern, as shewn in Fig. 12.
The air vessels in this instance are united by cables passing longitudinally
from one to the other under the bottom or bilges of the ship. The two
ends of each cable are carried up on deck through the chain ports a, a,
and hauled tight by the windlass and capstan, slips of chain at b, c, and d,
are attached to the cables and to the air vessels, passing over rollers, if
necessary. The air vessel, on inflation, pressed upwards by the water, and
swinging out from the vessel, pulls the slips of chain in the same direction,
turning on the point at 6 as on a sort of centre of action, which motion also
causes the air vessel to escape contact with the rudder. In this way the
burthen of the ship is thrown entirely upon the cables under her bottom.
Figs. 13 and 14 represent the stem and stern views, and the appearance of
the cables on the bow and stern. This mode is applicable chiefly to ships
when light, and the air vessels, by rising higher out of the water, lose effect
proportionably.
Fig. 15 shews the application of a pair of air vessels of the cylindrical
shape, as in Fig. 7, fixed to the ship; a, a, the water line.
Fig. 16 represents the side elevation of a ship, with places where ring bolts
or hooks, a, a, may be inserted, and the rings in them be used for making fast to
the air vessels, to prevent the need of passing the holding tackle under the
ship's bottom. The air vessels are to be attached to them by means of an iron
rod or rods b, b, run through thimbles in the holding tackle of the air vessel;
the rods, when hauled up the side of the ship, get under the rings or hooks in
her sides (which, when unemployed, may be let in flush with the ship's sides),
and being once hauled tight, the inflation of the air vessel will keep them so.
With regard to the most suitable and easy method of shipping the air vessels
in their proper places, this will very much depend upon the position and
circumstances of the latter. The globular air vessels may be applied in the
following manner :-The ship being afloat at the time, each pair of air vessels
should be kept rolled up (when not in use), with all their tackle ready, some-
thing after the manner in which a mainsail is rolled up for being carried to or
from a ship, they will then have somewhat of the appearance given in the
sketch; a, a, at Figure 17, are the two air vessels rolled up; b the rope work
uniting them; the part 6 is dropped over the stern, and the collapsed vessels
a, a, over the quarters, the latter being held on by the ropes d, d, each of which
has a noose, in which each air vessel is held or lowered down until secured.
When the part 6 is below the keel, the whole is hauled forward by the ropes
d, d, on each side of the ship to their proper place; the ropes e, e, are then
hauled up, but having been previously passed through thimbles in the nooses

page_text: , i, they slacken and pull up the nooses at the same time, and the ropes c, c,
and g, g, being hauled horizontally, one a little forward, the other a little aft of
the air vessel where they are made fast; the latter is completely opened out,
the ropes e, e, being also first made fast on deck; the upper ends of the hose
ff, are screwed on to the bellows or air pump on board the vessel. The
second and third pairs of air vessels are then put on the ship in a similar
manner, when inflation commences, and the ship will rise in the water. The
air vessels may be put over the bows of the ship, if a small double chain be
kept constantly hanging there, as shewn at b, b, in Figure 14. The chain
communicating with both sides of the ship, one of the ropes d with its
air vessel, by being made fast to the chain on one side, is passed under the
bowsprit to the other side of the ship, by the chain being hauled upon the
rope or bottom part b, is then thrown overboard, and the whole is lowered down
and fixed as before described. I would here remark that the air vessels may
be made or constructed of any desirable form, but for the sake of perspicuity,
I have confined my illustrations to the globular and the cylindrical, and for the
reasons above stated, the globular or spherical form is much to be preferred.
I would, also observe, that metal, wood, or other hard material may be used
for the cases of the air vessels, with holes for the water to run out when the
iuterior air vessel is being inflated, and provided with an aperture or moveable
lid for the insertion of the air vessel therein, and another aperture for the
hose.
These improvements for lessening the draught of water of vessels are also
to be applied internally, and must be suitably arranged and modified to the
adaptation of the interior of sea-going or other vessels, as the circumstances
may require.
Firstly, the air vessels, with their furniture, already described, are adapted
for vessels carrying little cargo, or having sufficient space in the ship for
inflating them, varying only the holding tackle, so that the air vessels may be
secured down to ring bolts or other fastenings into the frame of the ship, in
number sufficient to divide the pull throughout the length of the ship when the
influent water (from springing a leak) bears the air vessel upwards.
Secondly, air vessels of metal, entirely iron, copper, tin, &c.; the last from
its cheapness is preferable. The shape of these must depend on that of the
spaces they have to occupy in the ship; like the former, when used internally,
they are chiefly intended for ships having large unoccupied spaces, as vessels of
war, channel and river steamers, &c. The globular figure of the air vessels for
strength and economy will here, also, answer best; and as the cubical contents
of spheres increase in a greater ratio than their surfaces, the larger it can be

page_text: made for the space allowed the cheaper. The cylindrical figure shewn in
Sheet 2, Figure 1, is the next preferable shape; but the square, oblong, conical,
or any other figure is applicable to this purpose; the object being simply to
occupy with an air vessel "every space in the ship, which, on her springing a
leak, would otherwise be occupied with the same bulk of water. The air
vessels are firmly secured down to the frame of the ship, as before mentioned,
(by chains or wire rope proportioned to their size,) being first filled with con-
densed air, and the aperture through which it is introduced hermetically sealed.
Figure 2 represents a longitudinal section of the after part of a river or channel
steamboat. a, the cabin; b, the unoccupied space under the cabin; c, the space
for ballast or (but only a small portion of it) for coals. The space 6, instead
of being left void, is to be filled with air vessels d, d. If the steamer, by collision
or other accident, now fills with water, the space which the water will occupy
is curtailed by the air vessels into such small compass that its whole weight,
added to the weight of the vessel and stores, will not augment her draft of
water over a few inches. If the air vessels be removed, the hold will be com-
pletely filled with water, the weight of which, added to the weight of the ship
and her other contents, will cause her to sink; the air vessel should, how-
ever, be placed as low in the ship as possible above the ballast. The necessity
for which will be apparent by supposing them placed in the space a, instead of
in b, the space would then be entirely occupied with water, and although the
air vessels in the cabin (whether of metal or cloth) would be sufficient to keep
her afloat, yet she must sink nearly to the water's edge by the greater weight of
water in the hold, and become in consequence more unmanageable. In the
same manner the hold of a first-rate ship of war will give more effect to the
air vessel than the space on the orlop deck, and the latter, for the same reason,
is preferable to the space on the first gun deck. This description of air vessels
is also applicable, but at a comparatively great expense, to ships carrying cargo,
by filling up therewith (in addition to flexible air vessels for inflation in the
cabin and forecastle) the following and similar vacant or lost spaces in every
vessel, namely, the spaces about the ship's entrance and run inside, the inter-
stices between the side timbers or frames, between the beams and carlines of
the upper and lower decks, the space reserved for "dennage" down the sides,
the bilges, and the floor, (being from six to nine cubic inches over nearly the
whole of the ship's interior surface under the berths, and all waste spaces in the s
cabin's state rooms, forecastle, &c.
b
Thirdly, for the interior of vessels, in which the entire capacity of the hold is
occupied with cargo, the following is a description of the most efficient ap-
paratus; namely, a lining or sack equal in capacity to the hold, or made in two

page_text: or more divisions, with mouths corresponding with the hatchways. The material
of the sack is india-rubber cloth, or cloth well oiled, with a canvas or other
strong covering or case on both sides, loose or forming together one substance
with the former, and by means of loops or ties on the canvas, united to another
cover of strong and durable material, as matted cordage, with a soft surface
next the canvas, and protecting the side of the canvas on the skin of the
vessel and the side exposed to the friction of the cargo. The side next the
skin, deck, and beams of the vessel, is made fast thereto by ties at suitable
points, to keep the sack in its place, or it may be more perfectly secured from
the friction of the cargo by a covering of strong boards keyed together by a
cross board, the latter at convenient points being secured by means of a screw
passing through it and through the cloth into the frame of the ship, the edge
of the aperture in the cloth being carefully bound round the screw, to preserve
its water-tight property from injury by the puncture. The lining may be taken
out for airing or drying, if necessary, after each voyage. The effect of this
apparatus is obvious. The whole frame of the ship, with its exterior and
interior planking, becomes a protection to the sack from external injuries to
which the ship herself is exposed, and so long as the sacks are uninjured, the
vessel, making water from any number or description of leaks, can only admit
as much water into the hold as can lie between the sack and the ceiling, or
between the timbers of the vessel, which would not, probably, augment her draft
of water more than an inch or two, the whole weight of the cargo pressing the
sack close down to the ceiling.
The second head of these improvements, namely, the apparatus for raising
vessels or other heavy bodies, consists (with the exception of a "jack," described
below) of the application and employment of the air cases already mentioned,
the tackle only being varied according to the position or nature of the
body to be raised. In the case of a vessel or a heavy body that is sunk in
deep water, holding tackle is attached to it in the usual manner. The tackling
of the air vessel or vessels is then conveniently attached, and as the latter
become inflated, the whole rises to the surface, or after being raised to the
proper height beneath the surface, is floated into shallow water. If it be
required only to raise the body a few feet, as on board ship, from a lighter or
boat alongside, or from on board ship to the pier or quay, a metal cased air-
vessel, represented at a in Figure 3, suppose of one ton weight, or one with a
case of wood, having weights to that amount attached, is to be used. The air
vessel, by means of a chain or rope secured to it, is lowered into the water, the
other end of the chain passing over a crane or pulley b to the body to be raised,
as a hogshead of sugar in a lighter boat. So long as the interior flexible air.

page_text: vessel is inflated it remains with its weighted case on the surface of the water.
As the air is allowed to escape, the water rushes through the holes into the
case, and it sinks with nearly the weight of one ton, which raises the hogshead
at the other end of the chain, if of lesser weight. By re-inflation, the descent
of the air vessel is checked at the proper point or brought again to the surface.
The flexible air vessels are applicable also to raising heavy bodies on land, with-
out the aid of water. For this purpose, such heavy bodies are to be laid on
the cradle, band, ropes, or chains uniting two air vessels, the air being first
exhausted from them. The inflation causes them to rise to a height propor-
tioned to their diameter, and the body lying beneath rises with them. By
simply extending the surface of the air vessels, and augmenting the degree of
condensation of the interior air, any supposable weight may be thus lifted.
Figure 4 represents a sort of "jack" for raising weight, which consists of a
strong cylindrical air vessel a, a, of india-rubber, cloth, or strong leather,
covered with the former, and moving in a strong iron frame b, b, by means of
pins c, c, fastened to it at the top and bottom, and passing through regulating
or steadying rings d, d, in the frame. The whole is provided with a strong
iron pillar e in the centre, on which the weight to be lifted is supported. In
the Figure the air vessel is represented as in a collapsed state or exhausted,
and its sides falling in. On inflation, it rises to the length of the pins, with
the weight under which it has been placed, the air within being first condensed
proportionably. The stop-cock f is then turned, and the air vessel remains
inflated.
The third head of these improvements, namely, the apparatus or machinery
for securing and sustaining weight, consists of an iron platform, on which are
secured air vessels of iron, or other suitable material, filled with condensed air,
and hermetically sealed, in number and capacity proportioned to the weight to
be sustained, and adapted to form floating piers for permanent bridges over
broard and deep rivers, and to sustain floating slips, lighthouses, or other erec-
tions afloat.
In Sheet 2, of the accompanying Drawings, Figure 5 represents an elevation
of a floating pier sustained by air vessels of iron well secured in a frame, with
portions of a suspension bridge of the same material. The air vessels are to
be moored by anchors and chains, or, as represented in the Plan, by the screw
pile moorings, which answer the purpose better. The air vessels are in such
number, and their available capacity is such as to obviate danger from injury,
and they are placed at a sufficient depth below low-water mark to escape the
agitation of waves, which is confined to the surface; being constantly immersed,
they are little affected by the rise and fall of tide, and being ballasted by addi-

page_text: tional weight below, sufficient to counteract any leverage on the piles of the
weight above water, they sustain or support the bridge with a sufficient
degree of steadiness; the piers. from the principle of their construction, being at
the same time uninjured by such vibrations as may occur from the action of
the wind or of heavy carriages crossing the bridge. The shape and number
of the air vessels may be varied as the circumstances may require.
Figure 6 represents a transverse section of the bridge, exhibiting an end
elevation of the pier, and Figure 7 a sectional plan view of the pier. a, a, a, a,
represent the screw piles, which I prefer to be of that description commonly
called "Mitchell's Patent," fixed at the requisite depth in the bed of the river,
and cross-braced in two heights, as shewn by the diagonal dotted lines; these
piles are to be fitted with air chambers, guides, and stops, to prevent such
chambers rising too high. b, b, is the air-chamber frame in three divisions, the
two upper for air chambers, and the lower for ballast; c, c, uprights rising
from the platform above the air chamber, and carrying the lower turn-plate and
framing d, d, which is a horizontal frame to receive a vertical spindle from the
upper turn-plate; e, e, turn-plates with rollers between them; f, f, pedestals for
the chains, secured to the upper turn-plate, and cross-braced over the roadway;
9, 9, the carriage way and footpath; h, h, are the chains passing over laddles
in the pedestals to the roadway; i, i, the river wall or pier; k, the point at
which another portion of the bridge may be locked. A circular rack may be
applied to the lower turn-plate, and a multiplying power, worked by a winch
or capstan, may be applied to it for swinging the bridge, if desired.
Figure 8 represents a plan for an arrangement of six spherical air chambers,
and Figure 9 an end elevation of the same. Slips or jetties for landing, thrown
out to any distance from the shore, as also lighthouses or other floating erec-
tions, are to be sustained and secured by similar means.
Lastly, I wish it to be understood that I am aware that air vessels of different
materials have before been applied in various ways to shipping and to other
heavy bodies immersed and afloat, but not of the peculiar construction, or for
accomplishing the results specified above; as, for instance, for the purpose of so
controlling the draft of water of a ship of any size, as to render her incapable
of sinking from any casualty below a certain safe point, and at the same time
investing those on board with the complete command of her position afloat, and
loaded so that for convenience, safety, or repairs, her ordinary draft of water
may, with facility, be lessened to any required degree, either from stem or stern,
or only at the fore or after part, or on either side alternately; nor, for the purpose
of raising vessels and heavy bodies, either to the surface of the water, or to a
given height on land, by apparatus of the construction above specified; nor,

page_text: lastly, for the purpose of sustaining and securing floating erections, and weight
of any kind afloat, by the means described above.
In witness whereof, I, the said John Wood, have hereunto set my
hand and seal, this Thirteenth day of February, in the year of our
T
1
11
1
Inrolled the Fourteenth day of February, in the year above written.