IMPROVEMENTS IN SHIPS OR VESSELS
Year: 1877

page_text: LETTERS PATENT to Archibald Henry Hamilton, of Cavan, Ireland, Clerk in
Holy Orders, for the Invention of "IMPROVEMENTS IN SHIPS OR VESSELS."
Sealed the 13th June 1878, and dated the 17th December 1877.
PROVISIONAL SPECIFICATION loft by the said Archibald Henry Hamilton
at the Office of the Commissioners of Patents on the 17th December 1877.
"IM-
ARCHIBALD HENRY HAMILTON, of Cavan, Ireland, Clerk in Holy Orders.
PROVEMENTS IN SHIPS OR VESSELS."
My Invention relates more particularly to sailing ships or vessels, and has for its
chief object so constructing and arranging the sails that the force of the wind shall
be made available to the maximum degree practicable for propelling the vessel.
In order to effect this object I arrange the sails at an angle to the vertical, having
the normal to their plane passing through the meta centre, or near it; and I by
preference make them of a hemi-spherical, segmento-spherical, or other curved form,
with the concavity directed towards the wind, and the horizontal curvature or bulgo
of the horizontal yards reversed at the hinder end of the sail, the hinder curvature
being prolonged, if necessary, in order to maintain the vessel's head right, acting thus
after the manner of the tail of a kite.
Both the forward and the backward lines of the sail should point in the direction
of the wind. These inclined or "sloping" sails may with advantage be divided into a
number of smaller sails, after the manner of the ordinary vertical sails, for the
facility of fast sailing.
The sails are arranged chiefly at the leeward side of the vessel, but for fine sailing
the whole free-board may be covered by a low sail or sails to windward, say, down
to the water level.
The windward set of sails, if it be considered advisable to carry a double fixed
set, may be made to open automatically to admit the wind to the leeward set; and
all sails may be balanced, hinged, or otherwise arranged in order to admit of their
being easily controlled, and adjusting themselves to the direction of the wind after

page_text: the manner of the sails at present used in small boats, or otherwise; and they
may be fitted with springs or similar contrivance, so as to yield under an undue
pressure.
I also propose to make the hull in two halves, that is to say, divided longitu-
dinally, the same being arranged at a suitable distance apart in order to increase
the stability.
The keels, like the sails, are also inclined, that is to say, the centre line of the
keels are arranged at an angle to the vertical central plane of the vessel, in lieu of
coinciding therewith; or the keels may be made moveable at will. It is preferred
to make them of the maximum area practicable, and to subdivide them after the
manner of the sails.
The vessel should also be loaded at the stern, so that the resistance of the water
will tend to lift the weight.
I also propose to subdivide the ship into separate moveable independently navi-
gable parts. A large portion of the cargo may be contained in separate water-tight
vessels, carried on an intermediate deck between the two halves of the hull, but not
quite down to the water level, so as to admit of their being readily removed and
floated when discharging the cargo
I also employ at the prow front a single or double balanced or unbalanced rudder,
so constructed as to be capable of being instantaneously released, in addition to the
ordinary rudder at the stern, whereby increased facility for steering and other
advantages are attained.
It is further proposed to carry lights and a watch during foggy weather on the
highest topmast, or on a topmast specially erected over it, and covered with small
sails suitably directed.
The vessel may also be rendered more buoyant by being formed or fitted at the
front with bags, cushions, receptacles, or chambers containing air, water, or soft
elastic substances; or it may be enclosed or partially enclosed, say, at the front
portion in a skin or casing of elastic material and slight construction projecting to a
suitable distance beyond the vessel proper.
The force generated by the resistance of the water to the releasing rudder herein-
before referred to, or to brakes or baffles specially provided, may be stored up so as
to be utilized for working a donkey engine, or otherwise as a motive power.
By the use of my Invention high speed and great safety and efficiency are
attained more economically than is possible in ships or vessels of the ordinary
construction.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Archibald Henry Hamilton in the Great Seal Patent Office on the
17th June 1878.
ARCHIBALD HENRY HAMILTON, of Cavan, Ireland, Clerk in Holy Orders.
PROVEMENTS IN SHIPS OR VESSELS."
"IM-
This Invention relates more particularly to sailing vessels, and has for its object
an improved method of constructing and arranging the sails of such vessels in order
that the force of the wind shall be made available to the maximum degree prac-
ticable compatible with safety for propelling the vessel, at the same time that a
much higher speed is attained in a far more economical manner than hitherto.
Heretofore all ships and sailing vessels have been so constructed as to carry sails
in a vertical plane. By such arrangement the force of the wind causes the vessel to
heel over to leeward with a variable and dangerous force, which frequently results
in causing the vessel to turn completely over, thus entailing considerable loss both
of life and property. Owing also to this construction and arrangement sailing
vessels are compelled to take in sail when there is a strong wind, which results in
their losing to a considerable degree the advantage of its propelling power, and a
consequent loss of speed.
Now in order to obviate these various disadvantages I construct and arrange the
sails of such vessels upon the novel principle of resolving every plane immersed in a
current of air or water into its normal. Every plane so immersed, and having a
resisting body attached to it which in any way causes it to move slower than the
current itself in the direction of such current or against the same, resolves into its
normal line, and a combined system of such planes resolves into a mean normal line
or force acting simply to propel or pull along such plane, and consequently, if the
mean normal line of a system of driving sails be directed towards the meta centre of
the vessel, the result will be to propel or pull the vessel along such line or plane
without any tendency to upset it, in a similar manner as a canal boat is drawn
along by the tow rope.
To carry out my Invention I first therefore adjust the existing sails of vessels in
such a manner that as far as possible the mean normal or perpendicular to their
plane, drawn from their mean centre of surface, shall point nearly towards the meta
centre of the ship, whereby the sails will have merely a propelling or pulling effect
in an inclined forward direction, instead of the combined driving and turning forces
at present possessed by them. In carrying out this method of arrangement it is
necessary to make allowances for the various curvatures of the sails.
All the sails of a vessel may be balanced, hinged, or otherwise arranged in order
to admit of their being easily controlled and adjusting themselves to the direction
of the wind, after the manner of the sails at present used in the front of some small
boats, or otherwise; and they may be fitted with weights, or with springs, or other
suitable contrivances, so as to yield under any undue pressure.
The advantages of my improved arrangement are, that while it tends to materially
obviate the danger of upsetting, swamping, or foundering, it allows of a much
heavier press of canvas being safely carried, and so considerably promotes the speed
of the vessel by utilizing the additional force of a strong wind, which has hitherto
been lost by the reefing or furling of all or some of such sails, as before mentioned.
My improved method of arrangement may be readily applied to vessels as at
present constructed without difficulty or any considerable expense.
In order that the force of the wind may be utilized to the utmost degree con-
sistent with safety for propelling the vessel, the sails are placed at an angle of, say,
about 45 degrees to the vertical, having the normal to their plane passing either
through the meta centre, or near it. I prefer to make such sails of a hemi-spherical
or segmento-spherical form, as indicated in the Drawing, or of any other suitable
curved form, with the concavity directed towards the wind and the convex curva-
ture reversed at the hinder end of the sail, the hinder curvature being prolonged, if

page_text: necessary, in order to maintain the vessel head-right, and acting thus after the
manner of the tail of a kite. The horizontal section thus resembles the letter S,
only with a slighter curvature, and the vertical section an arc of a circle or ellipse.
Both the forward and backward lines of the sails point nearly in the direction of
the wind, so that as the wind enters and leaves them it possesses nearly its original
direction.
For the purpose of facilitating fast sailing such inclined or sloping sails may
advantageously be divided into a number of smaller sails, after the manner of the
ordinary vertical sails; and to obviate their having too great a lateral projection,
such sails may be arranged in vertical tiers, like Venetian blinds, resolving into
their various mean normals; and sails so arranged will give any required resultant.
In order further to illustrate how my improved method of arrangement may be
applied to ordinary vessels, I will now speak of it as applied to a common cutter.
I lengthen the check ropes of the jib and foresail of such a craft sufficiently to allow
the sail to go farther out with the wind. The mainsail, which swings at the back
of the mast, now turns round a vertical line, which serves as a hinge, and therefore
preserves a nearly vertical plane, the azimuth of which changes when the vessel goes
on the other tack.
Instead of this arrangement I unloose such mainsail from the mast at the bottom,
and allow it to turn round the upper swinging boom, which sways from one side to
the other, and projects backwards and upwards. By this arrangement the mainsail
assumes a proper and thoroughly secure position, as I take care to secure both the
boom and the sail in such a manner that the latter has only a limited revolution
around the boom; or, if preferred, the mast may be fixed so as to have a backward
slope at an angle of, say, about 60° to the vertical, and the sail may be hinged to it
in a similar way as at present done. The result of this inclination of the sail is that
the atmospheric pressure propels the vessel without upsetting it. Such rig closely
resembles that of a small pleasure boat, only that the sail hangs so freely that if a
mirror be laid along the plane of the sail at the centre, such mirror would reflect the
eye of an observer placed at the meta centre to itself. This position of the sail
ensures perfect safety and avoids all rocking of the vessel, while the co-efficient of
resistance due to that portion of the hull which is immersed is diminished by the
same atmospheric pressure if the sail be placed at the leeward side, as there is a
lifting impetus in the inclined pull forward which continually tends to raise the
hull out of the water, and the higher the hull the greater the speed.
The resistance of the air to the upper portion of the hull, as well as to the surface
of the sails, limits the speed where only a single mast and sail is employed, but any
suitable and convenient number of masts and sails may be arranged in line along the
length of the vessel.
It is obvious that the same principle of arrangement may be applied to all or any
of the sails of a larger craft, and by this means the size of the sails may be greatly
increased, and considerable additional power thus obtained, while the present full
spread of canvas may be maintained even in very strong winds, and thus dispense
with the operations of furling and reefing In constant moderate gales, such as those
which frequently prevail in the Atlantic, great speed may be thus obtained when
running at an angle of, say, 45° to 60° against the wind, and even in variable winds
there will still be a considerable advantage.
In order to diminish the leeway on the vessel I employ one or two knife edge
outrigger boards detached from the hull, whose normals point to near the middle
of the sails. One depresses the windward while the other raises the leeward side,
thus counteracting the ordinary tendency of the wind; and if strongly attached, such
outriggers will dispense with the necessity for ballast.
When the wind is light the head resistance of the air is relatively very important.
I therefore employ a covering foresail, the horizontal lines of which point into the
wind's eye, while the surface, sloping upwards and forwards, exercises a lifting effect
upon the prow of the vessel.
To obtain a high speed out of a low wind a number of masts must be employed

page_text: in order to afford a much greater visible surface to the current of air on the bow
than to the air against which the vessel runs directly in her course.
The curvature of the sails is important, and it will be found that sails prolonged
at a sharp angle to near the water's edge on the leeward side afford great lifting
power.
My improved method of construction is particularly adapted for despatch boats
and other similar vessels requiring great lightness, strength, and speed.
Having thus particularly described and ascertained the nature of my said Inven-
tion, and the manner of carrying the same into effect, I would have it understood
that what I claim is, the arrangement and use of one or more inclined or sloping
driving sails, the mean normal or normals whereof point nearly to the meta centre
of the vessel, whereby the resultant force becomes a simple push or pull along the
normal line, sloping forwards and upwards, and thus resolving every plane immersed
in a current into its normal, together with one or more outrigger boards, substantially
in the manner and for the purposes herein-before set forth and described.
In witness whereof, I, the said Archibald Henry Hamilton, have hereunto set
my band and seal, this Fifteenth day of June, in the year of our Lord One
thousand eight hundred and seventy-eight.