IM- PROVEMENTS IN FOLDING BOATS OR VESSELS
Year: 1878

page_text: LETTERS PATENT to Jolm Wallace Douglas McDonald, of Bembridge, in the
Isle of Wight, Rear-Admiral in the Royal Navy, for the Invention of "IM-
PROVEMENTS IN FOLDING BOATS OR VESSELS."
Sealed the 25th October 1878, and dated the 30th July 1878.
PROVISIONAL SPECIFICATION left by the said John Wallace Douglas
McDonald at the Office of the Commissioners of Patents on the 30th July
1878.
JOHN WALLACE DOUGLAS MCDONALD, of Bembridge, in the Isle of Wight, Rear-
Admiral in the Royal Navy. "IMPROVEMENTS IN FOLDING BOATS OR VESSELS."
My improved folding boats or vessels are composed of longitudinal sections or
parts (tapered or gradually narrowed towards each end) of stiff bendable elastic
material, connected together by continuous longitudinal waterproof hinges or joints.
Such a boat or vessel may be constructed so that when closed up it will be flat,
and when opened out the curvature of the bottom of the boat, as seen in side eleva-
tion will conform to the curvature of the lower edge of the longitudinal section or
part constituting the juxtaposed side, and the curvature of each side of the boat or
.vessel, as seen in plan, will correspond to the curvature of the outer edge of the
juxtaposed longitudinal section forming part of the bottom of the boat or
vessel.
The boat or vessel may be kept expanded or opened out for use by thawrts and
stretchers.
The material employed in the construction of the longitudinal parts or sections
is wood, steel, or other substance, such as will automatically resume its normal flat
or plane form when the stretcher is withdrawn.
In some cases I construct boats or vessels in longitudinal sections or parts con-
nected together by continuous longitudinal waterproof hinges on my plan, to close
up into a hollow form, somewhat resembling that of the well-known cigar ship.
Such boats of different sizes may be stowed one within another so as to economise
space.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said John Wallace Douglas McDonald in the Great Seal Patent Office
on the 30th January 1879.
JOHN WALLACE DOUGLAS MCDONALD, of Bembridge, in the Isle of Wight, Rear-
Admiral in the Royal Navy. "IMPROVEMENTS IN FOLDING BOATS OR VESSELS."
My improved folding boats or vessels are composed of longitudinal sections or
parts (tapered or gradually narrowed towards each end) of stiff bendable elastic
material, connected together by continuous longitudinal waterproof hinges or joints.
Such a boat or vessel may be constructed so that when closed up it will be flat,
and when opened out the curvature of the bottom of the boat, as seen in side eleva-
tion, will conform (or approximately so) to the curvature of the lower edge of the
longitudinal section or part constituting the juxtaposed side (as seen in side eleva-
tion when the vessel is open) and the curvature of each side of the boat or vessel,
as seen in plan, will correspond (or approximately so) to the curvature of the outer
edge of the juxtaposed longitudinal section forming part of the bottom of the boat
or vessel (as seen in plan when the vessel is open).
The boat or vessel may be kept expanded or opened out for use by thwarts and
stretchers.
The material employed in the construction of the longitudinal parts or sections
is wood, steel, or other substance, such as will automatically resume its normal flat
or plane form when the. thwart or stretcher is withdrawn.
Referring to the accompanying Drawings,—-
Fig. 1 shows in side elevation a vessel conssructed according to my Invention,
the vessel being in this view shewn open; Fig. 2 is a plan view of the same vessel,
also shewing it open, but with the masts lying down.
Fig. 3 is a plan view of the vessel, shewing it closed up or folded; Fig. 4 is a
cross sectional view, shewing the vessel closed up or folded.
In this vessel the bottom 1 is made in one piece; it may be of pine or mahogany,
or other suitable wood. The shape of the bottom is seen in Fig. 3 by the outer
line 2, which indicates the configuration of the bottom. To each side of the bottom
is hinged or jointed, by a continuous hinge or joint of leather 3, a side 4, which
may be of similar material to the bottom of the boat or vessel, or of other analagous
or suitable material. The lower edge of each of these sides is originally made of
precisely the same configuration as the corresponding or juxtaposed side of the
bottom 1, so that when a side and bottom are both flat if one be laid upon the
other the curved edges of the same respectively shall coincide, or nearly coincide.
The mode in which I have found it convenient in practice to form the hinges or
joints is shewn clearly in Fig. 4, where 3, 3, are strips of leather, prepared in oil,
in the same way as leather is prepared for making fire-hose (leather pipes). This
leather is called "hose butts."
5 and 6 are battens or strips of substance able to bend to the curve of the
bottom of the boat or vessel without breaking, and sufficiently hard and tough to
hold a clenched copper nail or rivet. American elm is very suitable for this pur-
pose; if soaked in water for about 24 hours it may be readily bent to the required
curvature. The strips of leather are secured to the curved sides of the bottom 1 by
copper rivets or nails passed through the battens 5, through the leather, and
through the bottom 1, and carefully clenched or burred. The sides 4 are similarly
fastened to the strips of leather. The sides are shorter than the bottom of the
boat or vessel; at the ends chocks 7 and 8 are secured to the bottom 1.
It will be evident that a boat or vessel constructed as just described may be
opened out, as shown in Figs. 1 and 2, in various ways, and may be kept so opened
out by a variety of devices or contrivances.
In the boat or vessel illustrated pieces of wood or metal 9, which I call
"spreaders," are secured by hinges 10 to the inside of the bottom of the boat.

page_text: above indicated, and shall produce a fair curve, like that given by a penning batten.
The bend of the wood then correctly indicates, a suitable curve.
}
Sometimes I cover the wood or stiff bendable elastic material (except metal)
with canvas fastened on by means of marine glue. Such a covering may be used
on one side only of the wood or on both sides thereof.
Sometimes I make the stiff bendable elastic portions of my boats of two thick-
nesses or layers of wood, secured together by marine glue, with the grain of the one
thickness or layer of wood at right angles to or crosswise of the other thickness or
layer of wood; and there may be a layer of canvas interposed between the two
thicknesses or layers of wood, or not.
As an additional precaution against entrance of water between the two thick-
nesses or layers of wood I cover the joint at the edges with canvas, as shewn in
Fig. 10, but embracing the two thicknesses of wood.
It is to be understood that I do not confine myself to the use of wood in forming
the stiff bendable elastic portions forming the sides and bottom of my boats or
vessels, but what I claim as my Invention is,―
The constructing folding boats or vessels of longitudinal sections or parts of stiff
bendable elastic material, having the juxtaposed edges of similar shape or curvature,
and substantially of the forms herein-before described, and connected together by
continuous longitudinal waterproof hinges or joints, substantially as herein-before'
described.
I also claim the construction of folding boat or vessel shewn in and described
with reference to Figs. 1, 2, 3, and 4 of the accompanying Drawings.
I also claim the construction of folding boat or vessel shewn in and described
with reference to Figs. 5, 6, 7, 8, 9, 10, and 11 of the accompanying Drawings.
In witness whereof, I, the said John Wallace Douglas McDonald, have here-
unto set my hand and seal, this Twenty-ninth day of January, in the year
of our Lord One thousand eight hundred and seventy-nine.
T77 D MCDONALD