IMPROVEMENTS IN PONTOONS CONSTRUCTED of Textile MATERIALS
Year: 1878

page_text: LETTERS PATENT to Isaac Blue Harris, of Castle Mills, Fountainbridge,
Edinburgh, for the Invention of "IMPROVEMENTS IN PONTOONS CONSTRUCTED
of Textile MATERIALS."
Sealed the 27th May 1879, and dated the 2nd December 1878.
PROVISIONAL SPECIFICATION left by the said Isaac Blue Harris at the.
Office of the Commissioners of Patents on the 2nd December 1878.
ISAAC BLUE HARRIS, of Castle Mills, Fountainbridge, Edinburgh.
MENTS IN PONTOONS CONSTRUCTED OF TEXTILE MATERIALS."
IMPROVE-
Pontoons constructed of textile materials are usually formed of canvas and other
strong cloth coated with india rubber and made up in the form required, which is
generally cylindrical, and filled with air, the india rubber being the water or air
tight material, and the canvas that from which the required strength is obtained.
In the construction of these pontoons heretofore, the stout and heavy canvas required
in respect of strength has always been the material made or sought to be made air
proof and water proof, but there are several disadvantages in so doing, and my
Invention consists in forming an air and waterproof bag of india rubber only, or of
india rubber coated cloth of a thin light texture, and in making a jacket of thick
and heavy texture such as canvas without any coating of rubber thereon to receive
the light air bag. Thus inside the strong jacket so formed is placed the air bag,
while outside may be placed a rope netting or other contrivance for carrying the
lifting attachments.
These cylindrical pontoons will in general be made with hemispherical or egg
shaped ends, and the form of the air bag will correspond therewith. The jacket I
form with a mouth through which to pass the air bag, and by preference on the
under side of the jacket, and of the length of the straight part of the cylindrical
pontoon. This mouth or opening is conveniently closed by threading or lacing.
The air bag is conveniently attached to the jacket by means of a longitudinal web

page_text: pierced with holes and connected with the lacing of the mouth of the jacket, and is
or may also be attached at the two ends, whereby the air bag and jacket will be
secured in proper relation to each other.
Great advantage will be obtained from this mode of construction. The jacket is
put together by sewing, and may thus be stayed, patched, and mended, and have
attachments or alterations made thereon or thereto from time to time that would be
impossible or troublesome with a pontoon where the materials for water proofing and
for strength are combined in making up, and inseparable afterwards. Furthermore,
the cost of production will be very much reduced. The bag and jacket can be easily
disengaged when not in use, and the textile portions readily dried, a matter of great
importance for durability and for the prevention from decay.
Another improvement is the employment of a web or covering of strong canvas
or similar material extending over the entire upper surface of the pontoon instead of
the rope netting usually employed with such pontoons, the advantage of which is that
this lifting web can be attached to the jacket, and will distribute the strain with
greater uniformity than can be got from rope netting which is less economical and
efficient than the web or canvas covering to the pontoon.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Isaac Blue Harris in the Great Seal Patent Office on the 28th May
1879.
ISAAC BLUE HARRIS, of Castle Mills, Fountainbridge, Edinburgh.
MENTS IN PONTOONS CONSTRUCTED OF TEXTILE MATERIALS."
"IMPROVE
Pontoons constructed of textile materials are usually formed of canvas or other
strong cloth coated with india rubber and made up in the form required, which is
generally cylindrical and filled with air, the india rubber being the water or air
proof material, and the canvas that from which the required strength is obtained.
In the construction of these pontoons heretofore, the stout and heavy canvas
required in respect of strength has always been the material made or sought to be
made air proof and waterproof, but there are several disadvantages in so doing, and
my Invention consists in forming an air and waterproof bag of india rubber only,
or of india rubber coated cloth of a thin light texture, and in making a jacket of
thick and heavy texture, such as canvas, without any coating of rubber thereon to
receive the light air bag. Thus inside the strong jacket of canvas is placed the air
bag, while to the outside is applied a rope netting or other contrivance for carrying
the lifting attachment.
These pontoons, when cylindrical, will in general be made with hemispherical or
egg shaped ends, and the form of the air bag will correspond with that of the
canvas jacket. The jacket I form with a mouth through which to pass the air bag,
and by preference this mouth will be situate on the under side of the pontoon and
.extend along the whole length of the cylindrical portion of the pontoon. This
mouth or opening is conveniently closed by a lacing passed through eylet holes in

page_text: the edges of the opening. The air bag is conveniently attached to the jacket by
means of a longitudinal web pierced with holes and connected with the lacing of
the mouth of the jacket, and it is or may be also attached at its ends to the ends of
the jacket. By this means the air bag and jacket will be secured in proper relation
to each other.
Great advantage will be obtained from this mode of construction.
The canvas
jacket is put together by sewing, and it may be stayed, patched, and mended, and
have attachments or alterations made thereon or thereto from time to time as desired.
This would however be impossible or troublesome with a pontoon where the
materials for water-proofing and for strength are combined in making up, and
inseparable afterwards. Furthermore, the primary cost of production will be very
much reduced. An incidental advantage of this Invention is that as the air bag
and jacket are readily detachable great facility is offered for drying the jacket or
canvas covering when the pontoon is not in use, a matter of great importance as
respects durability by preventing the rotting of the canvas.
In some cases I propose to employ a web or covering of strong canvas or similar
material extending over the entire upper surface of the pontoon as a substitute for
the rope netting usually employed with such pontoons. The advantage of this web
or covering will be that besides being economical it will, when attached to the
jacket, distribute the strain with greater uniformity than rope nettings.
Having now set forth the nature of my Invention of "Improvements in Pontoons
Constructed of Textile Materials," and explained the manner of carrying the same
into effect, I wish it to be understood that under the above in part recited Letters
Patent I claim,―
Constructing pontoons in the manner and for the purpose above set forth.
In witness whereof, I, the said Isaac Blue Harris, have hereunto set my
hand and seal, the Twenty-third day of May, in the year of our Lord One
thousand eight hundred and seventy nine.
T
חזנות IT
I. B. HARRIS. (1.5.)