IMPROVEMENTS IN MACHINERY AND APPARATUS FOR RAISING SHIPS AND OTHER VESSELS OUT OF THE WATER FOR THE PURPOSES OF EXAMINATION, CLEANING, OR REPAIR, SOME OF WHICH ARE APPLICABLE TO THE DOCKING OF VESSELS FOR THE SAME PURPOSES
Year: 1861

page_text: Strand, in the County of Middlesex, at present residing at Rio de
Janeiro, in the Brazils, for the Invention of "IMPROVEMENTS IN MACHINERY
AND APPARATUS FOR RAISING SHIPS AND OTHER VESSELS OUT OF THE WATER
FOR THE PURPOSES OF EXAMINATION, CLEANING, OR REPAIR, SOME OF WHICH
ARE APPLICABLE TO THE DOCKING OF VESSELS FOR THE SAME PURPOSES."
Sealed the 25th March 1862, and dated the 3rd October 1861.
PROVISIONAL SPECIFICATION left by the said Henry Law at the
Office of the Commissioners of Patents, with his Petition, on the 3rd
October 1861.
I, HENRY LAW, Civil Engineer, of No. 15, Essex Street, Strand, in the
County of Middlesex, at present residing at Rio de Janeiro, in the Brazils, do
hereby declare the nature of the said Invention for "IMPROVEMENTS IN MACHINERY
AND APPARATUS FOR RAISING SHIPS AND OTHER VESSELS OUT OF THE WATER, FOR THE
PURPOSES OF EXAMINATION. CLEANING, OR REPAIR, SOME OP WHICH ARE APPLICABLE TO
THE DOCKING OF VESSELS FOR THE SAME PURPOSES," to be as follows:-
In inclined slipways for the heaving up of vessels out of the water it has
heretofore been customary to employ some fixed source of power at the upper
[Price 8d.]

page_text: end of the slipway, and to impart motion therefrom to the cradle upon which
the vessel is supported by means of a chain or rope, and in the case of large
vessels, when a very heavy chain is required, much inconvenience and difficulty
is experienced in disposing of such portion of the chain as has been hauled up,
and power is lost in having to move the chain in addition to the cradle. To
remove these difficulties attach the machinery by means of which the cradle is
to be moved to the cradle itself, so that the two move together without the use
of any rope or chain (otherwise than as such may be employed as the means of
connection), and I effect this by constructing a powerful rack upon the slipway,
against the teeth of which a pinion or an endless screw moved by the
machinery attached to the cradle is made to bear, and thus a continuous pro-
gressive motion is imparted to the cradle either to raise or lower it along the
slipway, or effect the same object by means of traction rods so formed as to
lay hold of the teeth of the rack or of studs or projections upon the slipway,
and which being moved alternately backwards and forwards by hydraulic
pressure, or by cranks, or by any other known mechanical means, lay hold of
the successive teeth or projections, and thus produce a progressive motion in
the cradle, and by having two or more of such traction rods suitably arranged
such progressive motion may be made continuous.
For convenience I place the moving power and machinery in a water-tight
vessel attached to the cradle, and carry the shaft or traction rods by which the
connection with the slipway is effected through stuffing boxes or glands, so as
to exclude the water. And, furthermore, I construct an air-tight chamber open
at the bottom. forming a species of diving bell, which is attached to the forc
part of the cradle in such a position as to cover the portion of the rack or slip-
way, against which the pinion, screw, or traction rods are working, so as to
enable them to be constantly under inspection, and to allow of a workman
removing any extraneous substance which might otherwise obstruct the
working of the machinery and the progressive motion of the cradle, and I form
the entrance to such air-tight chamber by a species of air lock so as to enable
a workman to pass into or out of the same without allowing the admission of
water, and maintain the requisite pressure of air by means of an air-
pump.
Furthermore, I construct the apparatus for the immediate support of the
ship or other vessel when grounded upon a cradle or in a dry dock of hinged
levers or jointed or flexible straps capable of adapting themselves to the form
of the vessel, so that by raising up or tightening the extremities of such levers
or straps a uniform support is afforded to the vessel, and the pressure is more

page_text: ovemy useionicu over its surface. In some cases 1 Connect such levers and
straps with cach other laterally by means of rods or ties arranged in such a
manner as to form a species of network, by tightening up the extremities of
which the sides of the vessel would be perfectly embraced so as to afford a
uniform and evenly distributed support.
Furthermore, I construct the blocks or supports upon which the vessel is
intended to rest, when grounded, either upon a cradle or in a dry dock, in such
a manner as to show whether the vessel is bearing upon or in contact with
each block, and also to show the moment at which such contact takes place
with each particular block or support, and this I effect by attaching to each
block an electrical apparatus so contrived that the contact between the block
and the vessel either makes or breaks an electric or voltaic circuit, and so
indicates to a person above the water, by striking a bell, deflecting a magnetic
needle, or by any of the other known means of a giving a signal, that the vessel
has taken a bearing upon the block. Or I effect the same purpose by having a
tube or other vessel capable of being compressed and filled either with air,
water, or any other suitable fluid, attached to each block, and so arranged that
when the ship comes in contact with the block the compression of the tube or
other vessel containing the fluid shall be transmitted to a pressure gauge or
other indicator placed above the water. Or I effect it by having a wire con-
nected to each block in such a manner that the grounding of the vessel upon
the block shall give motion to the wire, which latter being carried to any
convenient point above the water in a similar manner to the wires of ordinary
dwelling-house bells, shall, by ringing a bell or moving an index or other
indicator, show that the vessel is in contact with the block.
Furthermore, construct the blocks or supports upon which the vessel is
intended to rest in such a manner that when the form of the vessel is not
known, or is supposed to have become altered from its having been strained or
hogged, or in any other case where a difficulty might occur in knowing how to
adjust the several blocks so as to insure each one receiving a due share of the
weight of the vessel, in any of such cases, the vessel being first grounded upon
the cradle, or in the dock, and then removed, shall show what space, if any,
was left between the vessel, and each particular block, giving it as it were a
perfect impression of her form so as to enable each block to be raised to such
a height as to insure its taking its due share in the support of the vessel, and
so to prevent the latter from being injuriously strained, and this I effect by
attaching to each block a moveable rod projecting above its upper surface, and
so arranged as to admit of its being pushed downwards by the vessel when in

page_text: the act of grounding, and remaining in whatever position it may so have been
placed, and so indicating by the height of its upper surface above the block
whai distance if any existed between the vessel and the block
SPECIFICATION
in pursuance of the conditions of the Letters Patent,
filed by the said Henry Law in the Great Seal Patent Office on the
3rd April 1862.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, HENRY
LAW, Civil Engineer, of No. 15, Essex Street, Strand, in the County of
Middlesex, at present residing at Rio de Janeiro, in the Brazils, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Third day of October, in the year of our Lord
One thousand eight hundred and sixty-one, in the twenty-fifth year of
Her reign, did, for Herself, Her heirs and successors, give and grant unto
me, the said Henry Law, Her special licence that I, the said Henry
Law, my executors, administrators, and assigns, or such others as I,
the said Henry Law, my executors, administrators, and assigns, should
at any time agree with, and no others, from time to time and at all times
thereafter during the term therein expressed, should and lawfully might
make, use, exercise, and vend, within the United Kingdom of Great Britain
and Ireland, the Channel Islands, and Isle of Man, an Invention for
"IMPROVEMENTS IN MACHINERY AND APPARATUS FOR RAISING SHIPS AND OTHER
VESSELS OUT OF THE WATER. FOR THE PURPOSES OF EXAMINATION. CLEANING, OR
REPAIR, SOME OF WHICH ARE APPLICABLE TO THE DOCKING OF VESSELS FOR THE
SAME PURPOSES," upon the condition (amongst others) that I, the said Henry
Law, my executors or administrators, by an instrument in writing under my, or
their, or one of their hands and seals, should particularly describe and ascer-
tain the nature of the said Invention, and in what manner the same was to be
performed, and cause the same to be filled in the Great Seal Patent Office
within six calendar months next and immediately after the date of the said
Letters Patent.
NOW KNOW YE, that I, the said Henry Law, do hereby declare
the nature of my said Invention, and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following
statement thereof,-and-accompanying Drawings: -

page_text: In inclined slipways for the heaving-up of vessels out of the water, it has
heretofore been customary to employ some fixed source of power at the upper
end of the slipway, and to impart motion therefrom to the cradle upon which
the vessel is supported by means of a chain or rope; and in the case of large
vessels, when a very heavy chain is required, much inconvenience and
difficulty is experienced in disposing of such portion of the chain as has been.
hauled up, and power is lost in having to move the chain in addition to the
cradle. To remove these difficulties, I attach the machinery by means of
which the cradle is to be moved to the cradle itself, so that the two move
together without the use of any rope or chain (otherwise than as such may be
employed as the means of connection), and I effect this by constructing a
powerful rack upon the slipway, against the teeth of which a pinion or an
endless screw moved by the machinery attached to the cradle is made to bear,
and thus a continuous progressive motion is imparted to the cradle either to
raise or lower it along the slipway; or 1 effect the same object by means of
traction rods so formed as to lay hold of the teeth of the rack, or of studs or
projections upon the slipway, and which being moved alternately backwards
and forwards by hydraulic pressure, or by cranks, or by any other known
mechanical means, lay hold of the successive teeth or projections, thus
produce a progressive motion in the cradle, and by having two or more of
such traction rods suitably arranged, such progressive motion may be made
continuous.
For convenience, I place the moving power and machinery in a water-tight
vessel attached to the cradle, and carry the shaft or traction rods by which
the connection with the slipway is effected through stuffing boxes or glands,
SO as to exclude the water. And, furthermore, I construct an air-tight
chamber open at the bottom, forming a species of diving bell, which is attached
to the fore part of the cradle in such a position as to cover the portion of the
rack or slipway against which the pinion, screw, or traction rods are working
so as to enable them to be constantly under inspection, and to allow of a
workman removing any extraneous substance which might otherwise obstruct
the working of the machinery and the progressive motion of the cradle; and I
form the entrance to such air-tight chamber by a species of air lock so as to
enable a workman to pass into or out of the same without allowing the
admission of water, and I maintain the requisite pressure of air by means of
an air pump.
This part of my said Invention is shown on Drawing No. 1, in which
Figure 1 is a longitudinal, and Figure 2, a transverse section of the water-

page_text: tight vessel containing the moving power and machinery. A is a ship resting
on the cradle B, supported upon rollers C, C, C, which run upon the lines of
rails D, D. A powerful rack E, E, extends along the centre of the slipway
in which are engaged the teeth of the pinion F firmly fixed to the shaft G,
the bearings of which rest in plummer blocks attached to the framing of the
water-tight vessel H. The shaft and pinion G and F are contained within
an air-tight chamber I, which being open at the bottom, and constantly
supplied with air from an air pump, forms a species of diving bell, and enables
a person to inspect the whole of the rack plate E during the progress of the
pinion, and to remove any dirt or other extraneous substance which may
have been deposited upon it. The entrance to and exit from this chamber is
effected by means of the vertical tube J, so arranged with double air-tight
doors K, K, as to form a species of air lock, and so to enable a person to pass
into or out of the chamber I, without allowing the escape of the compressed
air or the admission of the water from below.. A second shaft L, which is
connected with G by the wheel M and pinion N, passes from the air-tight
chamber I into the water-tight vessel H, through a stuffing box O, so as to
prevent the compressed air from escaping from the former. The steam engine
with its boiler (or other motive power) is placed within the vessel H, as in
the engine room of an ordinary steam boat, and being connected with the
shaft L, imparts its motion through the wheel and pinion M and N to the
pinion F, and so causes the vessel to move upwards or downwards along
the slipway, carrying with it the cradle B and ship A, to the former of which
it is connected by a powerful coupling P. To enable the person within the
chamber to communicate promptly with the person in charge of the machi-
nery, so as to have the same immediately stopped, should any impediment be
met with upon the rack plate E, a small shaft or spindle Q is carried through
an air-tight stufling box on the side of the chamber, having two hands or
indexes fixed immovably and parallel, one at either extremity, and two similar
dial plates, one on either side, so that either index being placed to any word,
signal, or direction upon its dial plate, the other index will point out the same
word, signal, or direction upon the other dial plate, and so communicate the
intelligence required between the persons within the chamber and the vessel
respectively. To attract immediate attention, the spindle should be so
arranged as to sound a bell whenever the indexes are moved.
Figure 3. Drawing No. 1. is a longitudinal section of a vessel similar to
that herein-before described, but in which the moving power is made to act
upon the rack plate E by means of an endless screw instead of a pinion.

page_text: The corresponding letters have the same significance as before; L is a shaft
to which the moving power is applied, and transmitted through the wheel M
and the pinion N to the endless screw R, which being engaged by the teeth
of the rack E, and its end bearings attached to the framing of the vessel H,
by its revolution imparts an upward or downward progressive motion along
the slipway to the vessel H, and consequently to the cradle with the ship
upon it.
Figure 4, Drawing No. 1, is a longitudinal section; Figure 5, a transverse
section and Figure 6, a sectional plan of a vessel, similar to that above
described, but in which the moving power is made to act upon the rack E, E,
by means of traction rods or pawls moved alternately backwards and forwards
by hydraulic pressure, and so formed as to lay hold of or press against the
teeth of the rack, and so to produce a continuous progressive motion in the
vessel H. The corresponding letters have the same significance as before;
S is the cylinder of an hydraulic press, and T is its plunger or piston, to the
crosshead of which two traction rods U, U, are connected by a joint; the
rods U, U, are attached at their further extremities to a cross beam V the
whole being so contrived, that when the plunger T is pushed into the cylinder S
(which I call its up stroke,) the cross beam V in moving with it, slides freely
over the surface of the teeth of the rack, but when the plunger is pushed out
of the cylinder. (or making its down stroke,) the beam V coming in contact.
with the front face of the teeth of the rack E, is stopped in its motion, and
the continued application of the power causes the cylinder S to move in the
contrary direction, or to ascend the slipway, carrying with it the vessel H,
to which it is immovably attached. The movement of the plunger T when
making its down stroke, is produced in the ordinary manner, by pumping
water or any other suitable fluid into the cylinder S through the pipe W when
the stroke of the plunger is completed, a valve X is moved, by which the
pipe is connected with the force pump while the pipe W is brought into
connection with an open tank or reservoir; the further extremity of the
pipe Y is made to form another small plunger or piston Z within a cylindrical
cavity formed in the center of the larger plunger T; by the continued action
of the force pump forcing fluid into the cylinder Z, the larger plunger T is
caused to move into the cylinder S, or to make its up stroke, the fluid contained
in the latter being displaced through the pipe W. As the plunger T moves,
it carries with it the traction rods U. U, and the cross beam V, the latter
sliding in the manner already described over the backs of the teeth of the
rack, until upon reaching the top of any one of the teeth the beam V drops

page_text: down in front of it in a position to engage it; at the same instant the valve A
is moved back into its former position, by which the pipe Y is brought into
connection with the reservoir, and the pipe W with the force pump, the con-
tinued action of which causes the plunger T again to resume its down stroke
and the vessel H again to move along the slipway. On each side of the
hydraulic press S, is a similar one of half the area a, a, with a plunger b, b,
bearing against a crosshead c, to which is attached the hinged strut or pawl d,
arranged (like the beam V) to slide freely over the back of the rack E, when
moved up the slipway, but to engage with and push against the face of the teeth
of the same when attempted to be moved in the opposite direction. Precisely the
same arrangement is adopied as that above described, for causing the plun-
gers b, b, to move alternately into and out of their respective cylinders, in
doing which by the action of the pawl d against the teeth of the rack E, the
cylinders a, a, and consequently the vessel H, to which they are fixed, are
moved with an intermittent action along the slipway in an upward direction.
The force pump by which the hydraulic presses are actuated being supposed to
move with a uniform speed, the up stroke of the plunger T will be performed
in as much less time than the down stroke as the area of the plunger T exceeds
that of the plunger Z, and the up stroke of the plungers b, b, in as much less
time than their down stroke as their areas exceed those of the plungers e, e,
or (according to the proportions shown on the Drawing) in about one-cighth
of the time; that is to say, if the plungers took four minutes each to make
their down strokes, they would require only half a minute to complete their
up strokes. Furthermore, it should be observed the relative lengths of the
pawl d and traction rods U, U, are so arranged that when the plunger T, is
commencing its down stroke, the plungers b, b, are in the middle of their
down stroke, and vice versa. From the combined action of these two
circumstances, it results that the upward motion of the vessel H, along the
slipway, due to the alternate movement of the plungers b, b, and T, in place of
being intermittent, becomes continuous and nearly uniform.
The second part of my said Invention consists in constructing the apparatus
for the immediate support of the sides of the ship or other vessel when
grounded upon a cradle, or in a dry dock, of hinged levers or jointed or flexible
straps capable of adapting themselves to the form of the vessel, so that by
raising up or tightening the extremities of such levers or straps, a uniform
support is afforded to the vessel, and the pressure is more evenly distributed
over its surface. In some cases I connect such levers and straps with each
other laterally-by-means of-rods-or-ties, arranged in such a manner as to form

page_text: a species of network by tightening up the extremities of which the sides of the
vessels would be perfectly embraced, so as to afford a uniform and evenly
distributed support. This part of my said Invention is shown on Drawing
No. 1. Figure 7 is a transverse section of the cradle, showing the ship at the
instant of grounding upon it, and resting upon the keel only. To the center
of the cradle on each side of the keel blocks, at convenient distances apart, are
attached the levers f, f, by the hinged joints g, g; upon their upper sides are
sliding blocks h, h, so arranged as to be capable of having their positions upon
the levers altered so as to suit the various forms of different ships; the outer
extremities of these levers are supported upon props or struts i, i, being so
arranged as to admit of their being raised and lowered by means of jacks or
ropes and pullies, or any other of the well-known mechanical appliances
suitable for such purpose. Figure 8 shows these levers raised so as to support
the sides of the vessel previous to the cradle being drawn up out of the water.
Figure 9 shows a modification in which in place of the levers jointed straps i, i,
are attached at one of their extremities to the center of the cradle, and at the
other to props or struts h, k, with the means of being raised or lowered as
already described. Upon lifting the ends of the straps they are brought into
contact with the sides of the ship, as shown in Figure 10, and being flexible
assume its form, by which means the ship is supported upon a much larger
number of points, and the consequent pressure upon each is proportionately
reduced, while the tendency to strain or alter the form of the vessel is con-
siderably diminished; the strap taking the place of the water in supporting
the ship in a much more perfect manner than with the present plan of sliding
blocks drawn against the ship's side. The levers or straps may be united
together with lateral tie rods, as shown in Figure 11, Drawing No. 2, so as to
embrace the sides of the ship in a species of network.
Another mode of arranging the flexible or jointed straps is shown in
Figure 12, Drawing No. 2, the straps i, j, being arranged in pairs, the upper
extremities of each pair being connected and supported by a prop or strut k
common to both, by which arrangement the straps assume a diagonal or
triangular position, and great additional steadiness and security are obtained.
The third part of my said Invention consists in constructing the blocks or
supports upon which the vessel is intended to rest when grounded either upon
a cradle or in a dry dock, in such a manner as to show whether the vessel is
bearing upon or in contact with each block, and also to show the moment at
which such contact takes place with each particular block or support, and this
I effect by attaching to each block an electrical apparatus, so contrived that

page_text: the contact between the block and the vessel either makes or breaks an
electric or voltaic circuit, and so indicates to a person above the water, by
striking a bell, deflecting a magnetic needle, or by any other of the known
means of giving a signal, that the vessel has taken a bearing upon the block;
or I effect the same purpose by having a tube or other vessel capable of
being compressed and filled either with oil, water, or any other suitable fluid
attached to each block, and so arranged that when the ship comes in contact
with the block, the compression. of the tube or other vessel containing the
fluid shall be transmitted to a pressure gauge or other indicator placed above
the water; or effect it by having a wire connected to each block in such a
manner that the grounding of the vessel upon the block shall give motion to
the wire, which latter being carried to any convenient point above the water
in a similar manner to the wires of ordinary dwelling-house bells, shall by
ringing a bell or moving an index or other indicator, show that the vessel is in
contact with the block.
Figures 13 and 14, Drawing No. 2, show one form of applying this part of
my said Invention. I represents either one of the keel blocks or one of the
sliding blocks for supporting the sides of the ship; to its upper part is attached
a hinged flap m, which is retained in the position shown in Figure 13 by
means of a counterpoise weight, or of a spring, so that it stands about an inch
above the general surface of the block until the vessel comes into contact with
it, depresses the ilap m, and brings it into the position shown in Figure 14.
On the under side of the block (within a recess) is fixed a small tube of
vulcanised Indian-rubber n, into one end of which is inserted a metal rod o, the
other extremity of which is connected with an arm or lever p attached to the
moveable flap m, and to which is also connected one of the conducting wires q
of a galvanic boattery or magneto-electric machine. Into the other end of the
tube is inserted the extremity of the other conducting wirer of the same
battery, the whole being so adjusted that when the flap m is raised, as shown
in Figure 31, the ends of the rod o and the conducting wire r within the
inbe n shall be in contact, and so allow of the electric or galvanic current
flowing through the closed circuit, and indicating the fact that it is 50 flowing
by the deflection of a magnetic needle or other known means, while upon the
vessel coming into contact with the flap m and pushing it down into the
position shown in Figure 14, the metal rod o being drawn away from the
conducting wire r, the electric or galvanic circuit is broken, and the knowledge
of this fact is imparted to an observer by the magnetic needle ceasing to be
deflected, or by any other of-the-known means of determining the existence or

page_text: cessation of an electric current. The rod o and conducting wire r are SO
attached to the tube as to render it impossible for water to enter into the
space between them, which would disturb the action of the apparatus; the
elasticity of the Indian-rubber allows the elongation of the tube n and permits
the separation of the rod o and conducting wire when the flap is depressed.
It is necessary that the conducting wire r should be entirely insulated from
contact with the water, and this may be effected by coating it with guita
percha or vulcanised Indian-rubber. It is not necessary that the second con-
ducting wire should be connected with the rod o, but only that it should
enter or dip into the water, which would itself form a sufficiently good conduct-
ing medium between the two.
In the arrangement above described the grounding of the ship is shown by
the electric circuit being broken. Figure 15 and 16, Drawing No. 2, show
another modification, in which the same fact is indicated by the circuit being
completed. is the block for the reception of the ship; is a vulcanised
Indian-rubber tube, fixed in a recess in the upper part of the block, so as to
project a small distance above it; into the two extremities of this tube are
inserted the two conducting wires q and r of a galvanic battery, their ends
being flattened out and attached respectively to the upper and under sides of
the interior of the tube . Under ordinary circumstances the natural elasticity
of the Indian-rubber would preserve the tube t in its cylindrical form, as
shown in Figure 15, and by causing the separation of the wires q and r, would
interrupt the current of electricity, but upon the ship resting upon the block s,
the tube would be compressed, as shown in Figure 16, the wires q and
brought into contact, the electric current established, and so the fact indicated
to the observer above the water.
Figure 17, Drawing No. 2, is an arrangement for showing the grounding
of the vessel upon the block by means of the compression of a tube filled with
oil, water, or other suitable fluid. s is the block for the reception of the ship;
anda vulcanised Indian-rubber tube, fixed in a recess in its upper surface, so
as partially to project above the same; to this tube a small rigid pipe u is
attached, terminating above the surface of the water in a glass tube (or
arranged in any other convenient manner for showing any variation in the
height of the contained column of fluid); upon the grounding of the ship upon
the blocks, the tube would be compressed, and the fluid thus expelled from
it would increase the height of the fluid column in the tube u, and give notice
of the fact by means of the glass gauge v.
も
The fourth part of my said Invention consists in constructing the blocks or

page_text: supports upon which the vessel is intended to rest when grounded either upon
a cradle or in a dry dock, in such a manner that when the form of the vessel
is not known, or is supposed to have become altered from its having been
strained or hogged, or in any other case where a difficulty might occur in
knowing how to adjust the several blocks, so as to insure each one receiving a
due share of the weight of the vessel, in any of such cases the vessel being
first grounded upon the cradle or in the dock, and then removed, shall show
what space, if any, was left between the vessel and each particular block,
giving, as it were, a perfect impression of her form, so as to enable each block
to be raised to such a height as to insure its taking its due share in the support
of the vessel, and so to prevent the latter from being injuriously strained; and
this I effect by attaching to each block a moveable rod projecting above its
upper surface, and so arranged as to admit of its being pushed downwards by
the vessel when in the act of grounding, and remaining in whatever position
it may so have been placed, and so indicating by the height of its upper surface
above the block what distance, if any, existed between the vessel and the block.
This part of my said Invention is shown in Drawing No. 2, Figures 18, 19, 20,
and 21, in which s represents one of the blocks for the reception of the ship,
and is a rod passing through a stuffing box or collar of Indian-rubber or
leather y, so as to impart to it, sufficient friction to prevent its moving except
by the application of considerable external force. A line or light rope w is
attached to an eye in the upper extremity of the rod, to enable it to be drawn
up into the position shown in Figure 18, the rod being prevented from being
drawn entirely out by the projecting head at its lower extremity. Figure 19
shows a line of keel blocks, arranged for the reception of a vessel, the keel of
which is known to be hogged, the whole of the rods having been left projecting
above the blocks; Figure 20 shows the vessel lightly grounded upon the same,
so as to touch only upon the blocks at the stem and stern, and touching at the
intermediate points only upon the tops of the sliding rods. It is obvious that
upon the removal of the vessel each rod will show the intervening space which
was left between the keel of the vessel and the block to which it belongs, and
this space being made up with timber packing on each of the blocks, the vessel
may then be safely grounded upon the blocks without any alteration taking
place in its form. The keel blocks thus prepared with the vessel grounded
upon them, are shown in Figure 21.
In conclusion, I wish it to be understood that I do not claim the particular
form or configuration of the several parts shown on the Drawings, which are
-to-be-regarded-simply as illustrations of the modes in which my said Invention

page_text: Firstly, the placing of the macmmery
ship is supported in a vessel directly attached to the cradle, and arranged in
the manner herein-before described, so as to allow of its travelling along the
inclined slipway underneath the water, and so imparting motion to the cradle
without the intervention of a rope or chain.
Secondly, the employment of a chamber filled with air attached to the fore
part of the cradle, so as to enable a person to examine each portion of the
slipway previous to the cradle passing over it.
Thirdly, forming the apparatus for supporting the sides of the ship of hinged
levers or flexible straps, or arranged as a network, so as to afford the vessel a
more uniformly distributed support.
Fourthly, the so constructing the blocks or supports for receiving the ship
that it shall be known when the vessel comes in contact with each block by a
signal given to an observer above the water.
Fifthly, the so constructing the blocks or supports for receiving the ship
that they shall retain and exhibit the form of the vessel, and so enable their
upper surfaces to be exactly adjusted for the reception of the same.
In witness whereof, 1, the said Henry Law, have hereunto set my hand
and seal, this Seventh day of January, in the year of our Lord Onc
thousand eight hundred and sixty-two.
HENKY LAW. (L.S.)