IMPROVEMENTS IN THE CONSTRUCTION OF SAILS FOR SHIPS AND OTHER VESSELS
Year: 1845

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, THOMAS
WILLIAM GILBERT, of Limehouse, in the County of Middlesex, Sail Maker,
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 Twenty-first day of July, in the ninth year of Her reign,
did, for Herself, Her heirs and successors, give and grant unto me, the said
Thomas William Gilbert, my exors, admors, and assigns, Her especial licence,
full power, sole privilege and authority, that I, the said Thomas William
Gilbert, my exors, admors, and assigns, or such others as I, the said
Thomas William Gilbert, my exors, admors, 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, Wales, and the Town of Berwick-upon-Tweed,
my Invention of "IMPROVEMENTS IN THE CONSTRUCTION OF SAILS FOR SHIPS AND
OTHER VESSELS;" in which said Letters Patent is contained a proviso that I, the
said Thomas William Gilbert, shall cause a particular description of the nature
of my said Invention, and in what manner the same is to be performed, to be
inrolled in Her said Majesty's High Court of Chancery within 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
Thomas William Gilbert, do hereby declare that the nature of my said Inven-

page_text: tion, and the manner in which the same is to be performed, are fully described
and ascertained in and by the following statement thereof, reference being
had to the Drawings hereunto annexed, and to the figures and letters marked
thereon, that is to say:―
My Invention consists,-
First, of improvements in the manufacture of what are called square sails
for ships and vessels.
Secondly, the Invention consists of improvements in the manufacture of
what are called gaff fore and aft quadrulateral sails. And,
Thirdly, my Invention consists of improvements in the manufacture of what
are called triangular sails.
And in order that my Invention may be fully understood and readily carried
into effect, I will proceed to explain the means pursued by me in performing
the same.
The object of the first part of my Invention is so to construct square sails that
they shall not belly to leward, which is effected by means of arranging the cloths
of which a square sail is made in such manner that the cloths being narrowest
between the seams at the middle of the sail, and then widening out as the
cloths depart from that narrowest part. The width of canvass for sail making
is made of the same width from end to end, and although when made up into
sails according to my Invention the width of each cloth between the seams will
vary, yet such variation is obtained by tho cloths overlapping to a greater
extent where the width of the cloth is narrowest between the seams, by which
great strength is obtained at and approaching to the centre of a square sail
made according to my Invention. Figure 1 shows a square sail mado
according to the first part of my Invention. The line a, b, is the middle of the
sail, from which line the several cloths of which each sail is composed diverges
diagonally, each cloth being narrowest between the seams at the vertical join
or seam a, b, and there the overlap of the selvages is the greatest, producing
great strength, and the width of seam decreases as the width of cloth between
the seam is required to be wider, as is clearly shewn by the Drawing; and the
effect of this arrangement of the cloths is, that the bellying will be in the
centre and not at tho leaches, by which the edges of the sail will be thin to
the wind, and enable a vessel to sail closer to the wind, as well as obtain greater
strength of sail than has been accomplished by the means heretofore resorted
to. I would remark, that I do not claim as new the diagonal placing of the
cloths from the centre outwards, as shewn in the Drawing, when not accum-
panied by the circumstance of having the width of cach cloth different at
different parts of its length, as herein described. In making square sails I

page_text: have found it desirable in forming the seams, that the seam which connects
the two pieces of the cloth should not run in direct lines from one end to the
other of a seam, but in a succession of inclined steps, by which I am enabled
to obtain a thin edge of a sail to the wind at the leaches, and yet not throw all
the strain on the centre line a, b; and I have in making square sails for the
top sail of a four hundred ton ship commenced the joining of the cloths at the
outer end of a seam, by sewing the cloth selvage to selvage for the first six
inches, then commence an overlap, so that at the end of the next three feet of
the seam the cloths may overlap an inch and a half, and at the end of the next
three feet of the seam the cloths shall overlap two and a half inches, at the end
of the next three feet three inches, and at the end of the next three feet tho
overlap shall be three and a quarter inches, and so continue it to the end centre
without more overlap. I would, however, state, that in thus giving the best
directions in my power for the making of square sails according to my Inven-
tion, I do not confine myself to the quantities above given, as they may be
varied, and they will necessarily be varied when making larger or smaller sails,
in which cases the seams will be made with more or less overlap, but a work-
man will adjust his overlap according to the effect he desires to obtain, and the
strength he desires to obtain, by the overlapping of the selvages and narrowing
of the width of cloth betwen the seams; and I believe that a range of from
two and a half inches overlap for the greatest width of seam for the smaller
sails to four inches overlap as the greatest width for the seams of the largest
sails will be found to be a good direction to the workman, such being, accord-
ing to the experience I have been enabled to obtain, the best information I am
capable of giving to the workman; but further experience may give evidence
or results which may justify the workman departing from the quantities above
given.
I will now proceed to describe my Invention as applicable to all quadru-
lateral fore and aft sails. Figure 2 shows a gaff and boom sail, made according
to this part of my Invention, in which it will be seen that the narrow width of
the cloths between the seams is at the fore leach, and the width of the cloths
between the seams widens as the cloths proceed outwards towards the after
leach, and I prefer that the cloths of which such a sail is made should be so
put together that the warp of the cloths runs at right angles to the after leach,
as is shewn. In the making this description of sails, as in the making of
square sails above described, the difference of width of the cloths at different
parts is produced by overlapping the selvages more or less, as will be seen in
the Drawing, and as before described; the seams are not produced by straight
lines from point to point, but in a series of inclined steps, as above explained.

page_text: I will now describe the third part of my Invention, which relates to the
manufacture of what are called triangular sails. And in order that this part of
my Invention may be understood, it is desirable to remark, that there have been
heretofore several modes of combining the cloths of a sail of this description
resorted to. First, the common construction, which consists in causing the
cloths of which a triangular sail is composed to run parallel to the leach;
secondly, what is called the cross cut; and thirdly, where the cloths run
parallel to the stay; and although my Invention is applicable to either of those
modes of making triangular sails, yet I prefer the last-mentioned arrangement
of cloths when making sails according to this part of my Invention; and indeed I
do not confine this part of my Invention to any particular mode of combining the
cloths into a sail, so long as the peculiar character of the Invention be retained.
Figure 3 shows a triangular sail, constructed according to my improvements,
in which it will be seen that the widest part of each cloth between the seams
is at a line (1, (2,) proceeding from the clue to the stay, and from that (the
widest part of the cloths) the cloths become narrower as they proceed upwards
above that line and downwards below that line, as is shown by the Drawing.
And it should be remarked, that the seams are made by a succession of
inclined steps, as before described, and not in straight lines, varying the
quantity of the overlap according to the dimensions of the sails, as before
explained. Figures 4 and 5 show other arrangements of triangular sails
where the cloths run in different directions to each other, and also to that
shewn in Figure 3. In all these Figures, however, the same principle of
construction is pursued, which consists in causing each cloth to be wider at
one part than at other parts, and narrowing off as the cloth departs from such
widest part; and it is the having the widest part of each cloth of which a
triangular sail is composed intermediate of narrower parts, that is to say, each
cloth in a triangular sail is narrower at some part between the seams than
some intermediate part of the same cloth which is at a distance from each end,
and this will be understood by examining Figures 3, 4, and 5.
Having thus described the nature of my Invention, and the best means I
am acquainted with for performing the same, I would have it understood that
I do not confine myself to the details herein described, provided the peculiar
character of construction described in respect to either class of sail be
retained.
In witness whereof, I, the said Thomas William Gilbert, have hercunto
set my hand and seal, this Nineteenth day of January, in the year
of our Lord One thousand eight hundred and forty-six.
T. W. (L.) GILBERT.

page_text: AND BE IT REMEMBERED, that on the Nineteenth day of January, in
the year of our Lord 1846, the aforesaid Thomas William Gilbert came before
our said Lady the Queen in Her Chancery, and acknowledged the Specifi-
cation aforesaid, and all and every thing therein contained and specified, in
form above written. And also the Specification aforesaid was stamped
according to the tenor of the Statute made for that purpose.
Enrolled the Twenty-first day of January, in the year of our Lord One