IMPROVEMENTS IN THE REEFING OF SAILS, AND IN THE MACHINERY OR APPARATUS CONNECTED THEREWITH
Year: 1866

page_text: LETTERS PATENT to Jonathan Davidson, of Edinburgh, in the County of
Mid Lothian, North Britain, for the Invention of "IMPROVEMENTS IN THE
REEFING OF SAILS, AND IN THE MACHINERY OR APPARATUS CONNECTED
THEREWITH."
Sealed the 20th July 1866, and dated the 10th February 1866.
PROVISIONAL SPECIFICATION left by the said Jonathan Davidson at
the Office of the Commissioners of Patents, with his Petition, on the
10th February 1866.
I, JONATHAN DAVIDSON, of Edinburgh, in the County of Mid Lothian,
North Britain, do hereby declare the nature of the said Invention of "Im-
PROVEMENTS IN THE REEFING OF SAILS, AND IN THE MACHINERY OR APPARATUS
CONNECTED THEREWITH," to be as follows, that is to say:
This Invention has for its essential object the rendering of the sails of ships
capable of being automatically reefed by the pressure of the wind at any
time, so that the power or force tending to propel the ship may never be
exceeded by any increase in the pressure of the wind, that is to say, when a
wind of a certain definite pressure is acting upon a certain area of sails the
vessel is propelled at a certain rate; in order that the vessel may be propelled
at the same rate under a higher wind pressure the area of the sails exposed
to the action of the wind is by means of this Invention contracted relatively
with the pressure.
The apparatus by which this Invention is carried into effect consists as
follows: The yards to which the sail is fixed are made capable of revolving,

page_text: and a coiled spring or springs or other suitable means for producing rotation
of the yards is or are applied to them to counteract the pressure of the wind.
A fusee wheel or wheels is or are applied to each of the yards, and a rope or
chain wound round them and the barrel or barrels containing the spring or
springs in a manner similar to the chain on the fusee wheel and spring barrel
of a watch.
When the wind increases in pressure it acts in consequence more forcibly
on the sails, and in tending to draw them out of their flat form into that of
a curve one of the yards is caused to revolve by the tension thus produced
on the chains or ropes, which action being communicated to the other yard
by means of the fusees and chains or ropes at their ends or central parts
causes the other yard also to rotate and wind up a portion of the sail, the
tension of the coiled spring being counteracted by the pressure of the wind
against the sail so that when the pressure of the wind again diminishes the
spring. unwinds the yard, and an increased area of sail is presented for the wind
to act against.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Jonathan Davidson in the Great Seal Patent Office on the
10th August 1866.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JONATHAN
DAVIDSON, of Edinburgh, in the County of Mid Lothian, North Britain, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Tenth day of February, in the year of our Lord
One thousand eight hundred and sixty-six, in the twenty-ninth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me,
the said Jonathan Davidson, Her special license that I, the said Jonathan
Davidson, my executors, administrators, and assigns, or such others as I,
the said Jonathan Davidson, my executors, administrators, or 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 "IMPROVE-
MENTS IN THE REEFING OF SAILS, AND IN THE MACHINERY OR APPARATUS CONNECTED
THEREWITH," upon the condition (amongst others) that I, the said Jonathan
Davidson, by an instrument in writing under my hand and seal, should

page_text: particularly describe and ascertain the nature of the said Invention, and in
what manner the same was to be performed, and cause the same to be filed
in the Great Seal Patent Office within six calendar months next and imme-.
diately after the date of the said Letters Patent.
NOW KNOW YE, that I, the said Jonathan Davidson, do hereby declare.
the nature of my said Invention, and in what manner the same is to be
performed, to be particularly described and ascertained in and by the tollowing.
statement, reference being had to the accompanying Drawings, and to the
letters and figures marked thereon, that is to say :-
My said Invention has for its essential object the rendering of the sails of
ships capable of being automatically reefed by the pressure of the wind at
any time, so that the power or force tending to propel the ship may never be
exceeded by any increase in the pressure of the wind, that is to say, when the
wind of a certain definite pressure is acting upon a certain area of sails, the
vessel is propelled at a certain rate; in order that the vessel may be propelled
at the same rate under a higher wind pressure, the area of the sails exposed
to the action of the wind is by means of this Invention contracted relatively
with the pressure.
The apparatus by which this Invention is carried into effect consists as
follows The yards to which the sail is fixed are made capable of revolving,
and a coiled spring or springs, or other suitable means for producing rotation
of the yards is or are applied to them to counteract the pressure of the wind.
A fusee wheel or wheels is or are applied to each of the yards, and a rope or
chain wound round them, and the barrel or barrels containing the spring or
springs in a manner similar to the chain on the fusee wheel and spring barrel
of a watch. When the wind increases in pressure it acts in consequence more
forcibly on the sails, and in tending to draw them out of their flat form one
of the yards is caused to revolve by the tension thus produced on the chains
or ropes, which action being communicated to the other yard by means of the
fusees and chains or ropes at their ends or central parts causes the other yard
also to rotate and wind up a portion of the sail, the tension of the coiled
spring being counteracted by the pressure of the wind against the sails, so
that when the pressure of the wind again diminishes the spring unwinds the
yard, and an increased area of sail is presented for the wind to act against.
And in order that my said Invention may be properly understood I shall
now proceed more particularly to describe several modes under which the
same is or may be used or practically carried into effect, reference being had,
for the sake of more complete elucidation, to the several Figures upon the 7
Slieets of Drawings which I have hereunto appended.

page_text: Before, however, proceeding to describe the several mechanical arrange-
ments, I deem it consistent and advantageous to point out more explicitly
than has herein-before been set forth the exact nature and object of my
said
Invention and its several modifications as follows:-In using the term "self-
reefing sails " I do not employ it to signify a meaning precisely corresponding
to that for which the expression bas hitherto been taken. The interpretation
which I give to the expression when used to designate this present Invention,
or any of its modifications is, the diminishing or enlarging of the area of the
sail exposed to the pressure of the wind in an inverse ratio to the increase or
decrease of the wind pressure itself, that is, as the pressure of the wind
increases the area of the sail exposed to its force is inversely diminished, and,
on the contrary, as the wind pressure diminishes the exposed area of sail is
inversely increased. By means of the apparatus for effecting the increased or
decreased area of the sail a force constantly of the same effect is obtained for
propelling the ship, and thereby several advantages are derived, amongst others,
in the event of a storm coming on suddenly at sea, and when with sails as
ordinarily constructed, the operation of furling or reefing would be dangerous
or impossible, the present Invention causes the sails to be spontaneously
reefed by the very pressure of the wind itself, so that the stress of a storm
upon a ship fitted with sails and self-reefing apparatus constructed according to
this Invention would be diminished in a very large ratio.
Another advantage is that the commander of a ship knowing the nature of
his cargo, and the rate at which he can safely travel with it, can before leaving
port or at any other time adjust the sails and self-reefing apparatus so as to
enable him to sail at any given rate, which rate becomes the balancing point
between the pressure of the wind and the tension on the balancing apparatus.
Other advantages are that the risk of breaking masts and rigging and the
overturning of a vessel are much lessened, and, in consequence of the various
modifications of which the Invention is susceptible, it can be applied with
equal facility to the smallest skiff or the largest ship afloat. There are several
other advantages to be derived from the use of this Invention, but which I
do not consider it necessary herein to specify, as they will be at once evident
to every practical seaman.
.
I now therefore proceed to describe the several mechanical arrangements
as set forth in the accompanying Sheets of Drawings.
On Sheet 1 Figure 1 is a side elevation of one modification under which
my said Invention is carried out in práctice; Figure 2 is a front elevation
corresponding to Figure 1; and Figure 3 is a plan of the same.
On referring to the Figure it will be seen that the mast A is fitted with

page_text: rings B and B, from which the brackts C and C project, the upper one C
carrying the shaft D, the ends of which are fitted with guide pulleys or rollers
E and E', the groove in which is recessed so as to receive the links of the
pitch chains F and F. The bracket C¹ on the lower mast ring B' is fitted
with bearings at a (which may be similar to those for the upper shaft D, or of
any other suitable kind) for the cross shaft G. At or about the central part
of the shaft G the weighted pulley or drum G is fixed, so that the shaft and
pulley or drum shall revolve together, a groove being provided in the pulley
or drum for the reception of the cord or chain by which the weight II is
suspended or attached thereto. At either end of the cross shaft G a fusee or
cone wheel I is fixed, and chains or cords J (which chains I prefer to call the
balancing chains) are shown wound thereon, one of their ends being attached
to loops or hooks L on each end bearing parts of the winding roller M.
Between the loops or hooks L and the chain pulleys N toothed pinions are
fixed, one at each end of the axle of the roller M and moveable racks P; the
inner ends of which are provided with eyes fitting over the shaft G gear into
the teeth thereof. The sail, which is indicated by the heavy line S in Figure 1,
by the shaded surface S in Figure 2, and seen in full front elevation in
Figure 3, is attached by its lower end or edge to the roller M, and by its
upper to the stretcher R, which is again secured to the pitch chains F and F¹,
as more particularly seen in Figure 1. The outer ends of the upper cross
shaft D and the winding roller M are well fitted into bearings in the upper
and lower ends respectively of the stretchers T and T"; thus the sail is held
suspended beween the four sides of a stiff frame. It is preferred to make the
stretchers T and T of malleable iron and of tubular construction, as under
this form a very high amount of rigidity compared with the weight of the
material employed is obtained. The stretchers may, however, be formed of
T, H, or section, or in any other way, or of any other form and material
that may be found convenient; this being a detail which is left more par-
ticularly to be settled by the ship constructor or naval architect,
Having now described the details of this first modification of my Invention,
I now proceed to point out the operation of the same.
The direction in which the wind is supposed to be blowing is at right angles
to the sides, as indicated by the arrows in Figures 1 and 3; thus, on referring
to the Drawings it will be evident that the sails are held in position by a
certain weight H, and as soon as the pressure of the wind multiplied into
the area of the sail itself exceeds the force of the weight H, and the natural
resistance to movement of the weight and friction of the several pieces of
framework, and the sail itself, an opposite force is produced greater than H

page_text: and the other above-mentioned counteracting forces; and in proportion as the
force represented in direction by the arrows is greater than the counteracting
force, in a corresponding degree is the sail blown out of its original position
towards the angle represented by the dotted radius and segment c, c, in
Figure 1; and in proportion to the extent of movement of the sail in this
angular direction, in a corresponding ratio is the sail S wound up on the
roller M, so that the portion of sail exposed to the wind is proportionately
reduced as the pressure of the wind itself increases, and on the wind pressure
again lowering the force represented by the weight H and the other resistances
above mentioned become greater than the opposing force of the wind dis-
tributed over the sail, in which case the sail itself approaches nearer to the
mast, and its exposed area is again enlarged to an extent corresponding to the
wind pressure necessary to maintain an equal propulsive effect.
The action of the apparatus shown in this modification is as follows:-As
soon as the wind blows the sail from the mast the balancing ropes or chains J
are stretched, and being wound around the fuses I on either end of the shaft G,
they, and along with it the weighted pulley or drum G', are turned round in
the direction of the arrow, by which movement the chain or rope by which the
weight H is suspended is wound on the drum or pulley and the weight itself
lifted, the racks P being stationary relative with the movement of the sail S;
therefore, as the sail moves from the mast or towards it respectively as the
intensity of the wind increases or diminishes, the pinions O are caused to
revolve, and along with them the sail roller M, therefore, in accordance with
the direction in which the sail moves it is accordingly wound on or off the
roller M. The pitch chains F and F¹ passing over pulleys of equal diameter
on the upper shaft D, and the winding-on roller M, the upper edge of the sail
attached to the cross bar or stretcher R has continually the same force
applied to it, and therefore the sail itself is kept constantly stretched.
It is obvious that in lieu of placing the fusees at the ends of the shaft G
that one fusee might be placed in the centre of the shaft and the weight
pulley G might be removed to any convenient part of the shaft; this arrange-
ment, however, would necessitate the sail being split down through the centre.
The weight H in this modification may be either a dead weight or it may be
a vessel or box in which part of the ship's cargo may be placed; thus by the
latter arrangement no additional weight over and above the cargo itself need
be carried. Although in the Figures illustrating this first modification the
pulleys E and N and E' and N¹ are shown of equal diameter, it is obvious
that their diameter depends on the length of the sail and the relative diameter
of the winding roller M and fusees I.

page_text: On Sheet 2 of my Drawings Figure 1 represents a side elevation; Figure 2;
front elevation; and Figure 3, a plan of the second modification of my said
Invention. In this arrangement in place of using a weight I employ a coiled
spring or springs like that of a clock or watch as the main force to counteract
the wind pressure.
In this modification A is the mast, and to it the lower
part of the sail is attached by the ring B, the cross shaft D being provided
with pitch pulleys for the reception of the links of the guiding chains F
and F, and the upper edge of the sail itself is secured by the top cross bar to
the chains, and by its lower edge to the winding rollers M, as in the preceding
arrangement, and need not be herein further referred to, as the same letters
of reference are affixed to corresponding parts in this as in the first modi-
fication. Distinction must be made between the dead weights employed in the
preceding modification and the coiled spring used in this second arrangement,
as well as the receding of the top in lieu of the lower edge of the sail, as seen
by the dotted angle and segment c, c, and the placing of the counteracting
force so as to act upon the upper in lieu of the lower edge, to the specifying
of which I now proceed. To the upper part of the mast an iron box G¹, or
one made of any other suitable material, is fixed by bolts, rivets, or otherwise.
The exterior shape or contour of the box such as it is preferred to employ
(although I do not confine myself thereto) is seen at G' at Figures 1 and 2.
Across its central part, or thereabouts, the shaft a passes, to which the coiled
spring contained in the spring box 6 is secured, the tension of the spring being
at first produced by winding it up by means of the pinion c, more particularly
evident by the pitch line c in Figure 1. The shaft a is provided with a fusee
wheel d, to which the rope or chain e, partly wound round the shaft G, is
attached; then, as the action of the wind on the sail causes the unwinding of
the balancing cords J off the fusees I, at the same time the cord e becomes
wound off the fusee a up on the spindle or shaft G. In place of using the
coiled flat spring directly, as previously described, it may be made sufficiently
long to transfer its power from the spindle of the spring box shaft to another
drum upon a parallel shaft, thus multiplying its power; from the spindle the
power is conducted to the fusees.
On Sheet 3 of my Drawings hereunto attached Figure 1 represents a side
elevation, and Figure 2 a front elevation of the third modification of my said
5 Invention. In this arrangement the greater number of parts are similar to
those shown and described in reference to the first modifications, a dead
weight H suspended from a pulley being shown as the force to counteract the
wind pressure, although a coiled spring or other elastic medium may be used
instead. The chief feature in this modification consists in not using a rack

page_text: and pinion for producing the rotation of the winding roller M, but in sub
stituting therefor a frame a attached, in the same manner as the rack in th
first modification, to the lower cross shaft. Across this frame a the cord o
chain c; passing also round the pulley b, is stretched, so that as the sail recede
from or approaches to the mast. the chain or cord c, being tightly pulled round
the drum b on the axis of the roller M, causes the winding on or winding of
of the sail. In this modification, as in the first, in lieu of placing the fusees
at the end of the shaft G, one fusee may be placed at the centre of the shaft.
Figure 3 on. Sheet 3 of my Drawings represents a side elevation of the
fourth modification. under which my said Invention may be put into practice.
In its principal features this modification corresponds to the first, the chief
difference, therefore, consisting in the employment of a long lever spring W
in lieu of a weight H, as shown at Figures 1 and 2 of the first Sheet of
Drawings, for producing the force to counteract the wind pressure; and in
order to get the spring W as short and to occupy as little room as possible
a small pulley a is substituted for the large pulley G' in the first modification,
so that the angular movements of the spring for winding up or unwinding a
portion of the sail is correspondingly reduced, which arrangement, however,
necessitates the introduction of a stronger spring W than would be necessary
if the pulley a were of larger diameter. These details, however, it is preferred
to leave to the judgment of the naval architect.
On Sheet 4 Figure 1 represents a side elevation of the fifth modification
of my said Invention. In this arrangement the chief part of the counteracting
apparatus is removed from the lower to the upper edge of the sail S, that is to
say, in place of the lower, edge receding from the mast, as in some of the pre-
ceding modifications, in this arrange.nent it is the upper edge which recedes,
as in the second modification, as shown by the dotted radius and segment c, c.
A stiff spring d is employed as the counteracting force, as in the fourth modi
cation, and the frame a and cord e passing round a drum on the shaft D, as in
the third modification, are here shown as applied to the counteracting of the 3
wind at the upper edge of the sail. The winding roller M is in this, as in
the preceding arrangements, placed at the lower edge of the sail, it being
preferred to so, situate it, because if placed at the
reasons more counteracting power would be required.
relatively with the wind pressure by means of pitch
the guide pulleys on the upper cross shaft D and
itself.
upper edge for obvious
The roller M is moved
chains F passing over S
the ends of the roller
Figure 2 on Sheet 4 is a part side elevation of a sixth modification of my
said Invention, in which the difference from the fifth consists in using the

page_text: racks a and pinions 6 for producing the winding movement of the roller, the
winding roller M, not seen in the Drawings, being placed at the lower edge
for the same reason as in the preceding arrangement.
Another peculiarity in this sixth modification consists in the use of a stiff:
bar B hinged to the mast at C, and acted upon by a spring D near to its
fulcrum, as the means for counteracting the wind pressure on the sail S. The
action of this arrangement is at once obvious on inspection of Figure 2,
Sheet 4, and therefore need not be again referred to.
Figure 3, Sheet 4, is a part side elevation of a seventh modification of my
said Invention, which is nearly similar to the first and second modifications
herein-before described, the only difference consisting in the employment of
the stiff bar a and spring b, as the means for counteracting the wind.
pressure.
Figure 4, Sheet 4, is a part side elevation of the eighth modification of my
Invention, which is generally similar to Figure 1 on the same Sheet of
Drawings, with the exception that a coiled or helical spring a is used as the
counteracting force; the action of the apparatus being in all respects similar
to the fifth modification need not be again specified.
:
Figure 5, Sheet 4, is the ninth modification, and this being generally
similar to the first and secoud and seventh modifications, with the exception
ouly that a coiled or helical spring a is employed to counteract the wind
pressure, need not be herein further described and referred to.
On Sheet 5 of my Drawings Figure 1 represents a side elevation of the
tenth modification of my Invention, and in which compressed air is used as
the medium to counteract the wind pressure. The inode in which the
counteracting medium is employed in this arrangement is as follows:-To
the mast A an air vessel B is secured, to which the cylinder C containing
the piston E is connected, a passage F being provided for the passage of the
compressed air to the upper side of the piston E. The action of the air is to
o keep the piston E at the bottom of the cylinder. To the piston a rod G is
secured which passes through a stuffing box at H; in its upper or outer end
an eye is formed, through which the chain or cord I is fastened, its other end
being wound round the small fusee on the shaft G'; accordingly their other
end acts upon the sail to cause it to recede from the mast A. In a corre-
sponding ratio is the cord or chain I wound up on the fusee on the shaft G¹,
and the piston E correspondingly raised, and on the wind pressure lowering
the elasticity of the air acting on the piston causes the sail to be drawn back
into its original position.
Figure 2, Sheet 5, represents this modification of my Invention slightly

page_text: varied, the difference in this from the preceding arrangement consisting in
attaching the toothed rack K to the upper end of the piston rod and causing
it to act upon the pinion L on the shaft G'. It is obvious that either of these
arrangements may be applied to any convenient part of the shaft G', and in
lieu of fixing the compressed air apparatus to the mast it may be situated on
any of the decks or in any convenient part of the ship; it may also be applied
to the upper in lieu of the lower part of the sail.
Figure 3, Sheet 5, shows the eleventh modification, being in fact another
arrangement of the first modification of my Invention, in which a stretched
india-rubber ring a is applied as the counteracting medium, and need not be
berein further referred to.
Figure 4, Sheet 5, shows the application of a similar stretched india-rubber
ring to the upper edge or side of sail, being the twelfth modification, and need
not be herein further referred to.
On Sheet 6 of the Drawings hereunto attached Figure 1 represents an
edge or side elevation, and Figure 2 a front elevation of the thirteenth
modification, In this arrangement the sail is made in two halves S¹ and S³,
and the inner corner of each half are hinged at their upper and lower ends to
projections on the mast rings B and B', so that they are free to move with
the inner edge of each half as an axis. Each outer corner of the lower or
under edge of the sail is coupled to the balancing cord I which is wound
round the pulley J (or this may be a fusee), therefore as the sail is blown out
of the flat position in which it is naturally held it causes the unwinding of
the balancing cord and consequent rotation of the weight pulleys or drums G
and lifting of the weights II, which are here shown as the counteracting medium,
although it is obvious that springs or elastic media of any of the kinds herein-
before described and referred to may be adopted. Each of the counteracting
shafts G in this modification are secured in bearings a, a, at either end situated
in the frame W. In place of arranging the sails as last described, the con-
stantly equal propulsive effect may be obtained by forming the sail in one
piece, and fixing its upper and lower edges firmly to the yards, as ordinarily
used, but in lieu of fixing the sails to the mast at a central line they are
swivelled thereto at some distance on one side of that line, so that the excess
of area of one side of the sail over the other half multiplied into the wind
pressure represents the balancing force, the effective surplus of area of course
varying with the angle of the sail. To the practical seaman or naval architect
it will be at once obvious that this last modification is capable of being
arranged so as to permit of the swivelling and balancing of any kind of sail
used in the smallest skiff or largest vessel afloat, even in sails of triangular

page_text: form, one of the edges may be made to swivel, whilst to one of the others a
spring or cord and weight may be so applied as to effect the variation of
the area relatively with the wind pressure to produce a constantly equal pro-
pulsive effect.
Figure 1 on Sheet 7 of the Drawings hereunto appended is a side elevation,
and Figure 2 a front elevation of the fourteenth and last modification
which I have considered it necessary hereunto to append. This modification
is in most respects similar to the first, so that the main portion of the
description which has reference thereto equally applies to this last arrange-
ment, and therefore need not be again referred to. I therefore proceed to
describe the difference in this from the first modification, which consists in
lengthening the stretchers at the lower end of the piece a, b, in order to
receive and hold the bar e, e, therein, as seen in Figures 1 and 2. The
introduction of this bar e, e, enables the fusee at the end, as shown in the first
modification, to be substituted by one nearer to the centre at c, from which
the balancing cord passes to the eye f on the bar e, e; the weighted pulley or
drum G¹ is removed a short distance from the centre of the shaft G¹. An
advantage which this modification possesses is, that whilst the fusee and
balancing cord is placed at or near to the centre of the shaft G, this is capable
of being effected by the introduction of the bar e, e, without necessitating the
division of the sails down the centre.
In the thirteenth modification of my Invention, in lieu of fixing the
balancing power to the mast, as shown in the Drawings referring thereto, the
fusee and balancing power may be placed in or upon a moveable post, pillar,
or bracket, and the balancing cord led therefrom to the sails, so that by
shifting and adjusting the pillar, post, or bracket carrying the fusee either
fore or aft the sails the balancing action may be obtained with the wind blowing
in any direction. In those arrangements in which lever springs or combined
lever and springs are used, the tension of these inay at any time be increased
or diminished by means of the set screw shown passing therethrough.
Having now described the nature of my said Invention, and several modes
under which the same is or may be used or practically carried into effect, I
would observe, in conclusion, that I do not confine or restrict myself to any
one of the particular arrangements which I have had occasion to describe and
refer to, as it is obvious that some of them are capable of still further
differences of arrangement, the details of which, after what I have shown
and herein set forth, may be left to the decision of the naval architect; 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,

page_text: First, the general arrangement and combination of apparatus forming the
means for effecting the "self-reefing" of the sails of vessels or boats, in the
manner and for the purposes substantially as herein-before described.
Second, the use of a dead weight of any kind, or part of the ship's cargo,
for effecting the balancing of sails, substantially as herein-before described
and combined with either of the modifications to which it is shown as applied
in the several Figures on the annexed Sheets of Drawings.
Third, the use and application of a coiled spring for effecting the self-reefing
of sails, and the mode of applying the same, substantially as berein-before
described.
Fourth, the use of a lever spring for producing the counteracting force for
effecting the self-reefing of sails, and the mode of applying the same, substan-
tially as herein-before described.
Fifth, the use of a stiff bar or lever acted upon by a spring for producing the
counteracting force for effecting the self-reefing of sails, and the mode of
applying the same, substantially as herein-before described.
Sixth, the use of a belical or spiral spring for producing the counteracting
force for effecting the self-reefing of sails, and the mode of applying the same,
substantially as herein-before described.
Seventh, the use of compressed air or gases for producing the counter-
acting force for effecting the self-reefing of sails, and the mode of applying
the same, substantially as herein-before described, or any mere modification
thereof.
Eighth, the use and application of an india-rubber ring or rings for pro-
ducing the counteracting force for effecting the self-reefing of sails, and the
mode of applying the same, substantially as herein-before described, or any
mere modification thereof.
In witness whereof, I, the said Jonathan Davidson, have hereunto set
set my hand and seal, this Eighth day of August, One thousand eight
hundred and sixty-six.
JUNATHAN DAVIDSON. (L.S.)