AN IMPROVED AIR CHAMBER FOR VARIOUS PURPOSES
Year: 1824

page_text: DICKINSON'S SPECIFICATION.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, ROBERT
DICKINSON, of Park Street, Southwark, in the County of Surrey, Iron Plate
Worker, send greeting.
WHEREAS His most Excellent Majesty King George the Fourth did,
by His Letters Patent under the Great Seal of that part of the United King-
dom of Great Britain and Ireland called England, bearing date at West-
minster, the Seventh day of December, in the fifth year of His reign, give
and grant unto me, the said Robert Dickinson, my exors, admors, and assigns,
His special licence, full power, sole privilege and authority, that I, the said
Robert Dickinson, my exors, admors, and assigns, during the term of years
therein mentioned, should and lawfully might make, use, exercise, and vend,
within England, Wales, and the Town of Berwick-upon-Tweed, my Invention
of "AN IMPROVED AIR CHAMBER FOR VARIOUS PURPOSES;" in which said Letters
Patent there is contained a proviso that if I, the said Robert Dickinson, shall not
particularly describe and ascertain the nature of my said Invention, and in
what manner the same is to be performed, by an instrument in writing under
my hand and seal, and cause the same to be enrolled in His Majesty's High
Court of Chancery within six calendar months next and immediately after
date of the said in part recited Letters Patent, that then and in such.
case the said Letters Patent, and all liberties and advantages whatsoever.
thereby granted, shall utterly cease, determine, and become void, as in and
by the same, relation being thereunto had, will more fully and large appear.
NOW KNOW YE, that in compliance with the said proviso, I, the said
Robert Robinson, do hereby declare that the nature of my said Invention,
and the manner in which the same is to be performed, is particularly described,

page_text: and ascertained in and by the following description thereof, reference being
made to the Drawings hereto annexed (that is to say) :-
My improved air chamber is made by inserting a number of small air vessels
within a larger air vessel or chamber, by which means, in the event of the
larger air vessel or chamber becoming injured, the smaller air vessels will
remain entire, and preserve the effect of buoyancy in the vessel or floating
apparatus to which they are attached. These improved air chambers are
applicable to a great variety of purposes and situations where buoyancy is
required. The external vessel or chamber may be made of metal or any other
material, rendered impervious to air and water by a coating of cloth, canvass,
matting, or other such substance saturated with paint, varnish, cement, or
other preparation. The internal vessels are to be waterproof bags or other
vessels, or animal bladders, or the esophagus of neat cattle, inflated with air,
or filled with pieces of cork, cork shavings, or cork broken almost into powder,
or other light substances that will float in water. It is utterly impossible that
I can enumerate all the situations in which these improved air chambers may
be employed with advantage; I shall therefore mention only a few, to which
they are obviously applicable (viz'):-Buoys, which are usually air vessels,
when constructed of metal, may be filled with secondary air vessels upon my
improved plan, for the purpose of keeping them buoyant even in the event of
external injury, such metal buoys being externally coated with cloth, canvass,
or other similar substance attached to the surface of the iron by means of a
strong impervious cement, so as to render the vessel perfectly air-tight at the
joints, and not liable to oxydation. A cement for this purpose may be made
by taking of caoutchouc (india rubber) one pound, of black resin half a pound,
of Venice turpentine two ounces, and mix them together, allowing them to
stand in a temperature of one hundred and sixty degrees for the space of
twenty-four or thirty-six hours, the caoutchouc being cut into small pieces; or a
composition may be made of resin and olive oil, linseed oil, or other oils, mixed
with pulverized bricks to the consistency of paste. Cloth buoys may be made
by filling suitably large air and water-tight vessels with air bags or bladders,
or bags filled with cork as above-said, the larger vessels being made of cloth,
canvas, matting, or other suitable substance saturated with the impervious
composition above described, or any other composition that will render the
cloth or other external coating perfectly water and air tight, the seams of the
vessel being also covered with strips of cloth attached by the same cement, and
the ends of the buoys being guarded with metal caps. Beds, bolsters, pillows,
cushions, the seat of chairs, backs and seats of sofas and carriages, and also
saddle for riding on horseback, may be made with these improved air
clambers, instead of the ordinary packing of feathers, wool, horsehair, and

page_text: other soft and elastic materials. For the latter purpose I should employ
small animal bladders, the esophagus or wezand of neat cattle, or oil-skin
bags inflated with air, cramed into air-tight cases made of any suitable
material prepared with an impervious composition. I also construct upon the
principle of my improved air chamber buoyant collars or bandages, to be worn
by persons to prevent them from drowning, which collars or bandages I make
of wezands (cesophagus), or waterproof vessels with pieces of cork, or crumbled
cork, or cork shavings tightly packed within and closed at the ends. And
further, these my said improved air chambers are particularly applicable to.
boats, barges, ships, and every other kind of floating vessel, for the purpose of
preventing the said vessels from sinking, even though they are filled with
water. In order to explain clearly the manner of adapting these my improved
air chambers to vessels, I have attached hereto a Drawing, exhibiting sections
of a boat with the improved air chambers. And first I should state that I
propose to construct such boats, barges, ships, and other vessels of iron or
other metal. In the Drawing hereto annexed, Figure 1 is the cross section
of a metallic vessel; Figure 2, a longitudinal section of the same, showing the.
manner of adapting my improved air chamber a, a, to the gunwale or hollow:
chamber, extending round the vessel, the whole of which is to be filled
with small air vessels, and externally made air-tight by riviting the joints of
the metal and afterwards covering the metal with cloth, canvas, matting, or
other suitable material which may be, according to circumstances, from the
thinnest gauze to the thickest Turkey carpet. This covering is to be attached
to the surface of the metal by means of a cement or composition that shall be
impervious to water. and air, such as the solution of caoutchouc, resin, and
Venice turpentine above described, or other suitable cement, which may be
laid upon the iron, and the coating of cloth or other material pressed upon it
until it adheres; or the cement may be laid upon the coating, or the coating
may be soaked in the cement, and then made to adhere. by pressing it upon
the surface of the iron. The interior of this air chamber is to be occupied
with air-tight bags made of oil skin or other material, or bladders or wezands
as aforesaid, filled with air or with cork, which air-tight vessels are to be
cramed into the chamber so as to fill it, by which means, in the event of any
external injury happening to the external air chamber so as to rend it, the
greater part of the chamber will still be buoyant. In a similar manner I form
air chambers. At 6, b, is the lower parts of the vessel, and also in the thwarts
c, c, rendering them air-tight by riviting the joints of the metal, and coating
the whole with cloth or other suitable substance as above said, which is to be
attached to the metal by means of an impervious cement as aforesaid. And

page_text: these air chambers I also fill with air-tight bags, bladders, or wezands contain-
ing air or cork; and also in the sides of the boat or ship, between the ribs and
double plates of metal, I construct air chambers upon my improved principle,
and fill these chambers with small air vessels as above described, or with cork
or cork shavings, by which means I render my said boats, ships, or other
vessels buoyant, even though filled with water.
Having thus described the manner in which I adapt my improved air
chambers to a variety of useful purposes, I wish it to be understood that I do
not confine myself to those purposes alone, but mean to apply them wherever
such improved air chambers may be desirable; and I do not confine myself to
the employment of bladders and oesophigus or wezands alone, but intend to
construct my small air vessels or bags of oilskin and other such materials as
may be made impervious to air and water, and to enclose such small air vessels
in the larger air vessel or outer case, made of metal coated with cloth,
rendered impervious to air and water in the manner abovesaid, or oilskin or
any other material that may be capable of forming an air-tight chamber; and
lastly, in adapting these my improved air chambers to all boats, ships, and
other vessels I do not confine myself to any particular kind or magnitude of
vessels, conceiving that the improved air chamber is alike applicable to the
smallest boat and the largest ship, consequently I do not adapt exclusively
the arrangement or disposition of the air chambers shewn in the Drawing, but
I claim every modo of disposing and arranging them that circumstances may
render desirable.
In witness whereof, I, the said Robert Dickinson, have hereunto set
my hand and seal, this Seventh day of June, in the year of our Lord
DOWDESWELL.
ROBT (L.B.) DICKINSON.
AND BE IT REMEMBERED, that on the Seventh day of June, in the
year of our Lord 1825, the aforesaid Robert Dickinson came before our said
Lord the King in His Chancery, and acknowledged the Specification afore-
said, 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.
Inrolled the Seventh day of Tune in the son of
Land One thous