AN IM- PROVED COMPOUND FOR COATING THE BOTTOMS OF SHIPS AND STRUCTURES, WHOLLY OR PARTIALLY IMMERSED IN THE SEA OR TIDAL ESTUARIES, AND IN THE SYSTEM OR MODE OF PREPARING THE SAME
Year: 1864

page_text: LETTERS PATENT to Alexander Dallas Hall, of Glasgow, in the County
of Lanark, North Britain, Gentleman, for the Invention of "AN IM-
PROVED COMPOUND FOR COATING THE BOTTOMS OF SHIPS AND STRUCTURES,
WHOLLY OR PARTIALLY IMMERSED IN THE SEA OR TIDAL ESTUARIES, AND IN
THE SYSTEM OR MODE OF PREPARING THE SAME."
Sealed the 19th April 1865, and dated the 7th December 1864.
PROVISIONAL SPECIFICATION left by the said Alexander Dallas Hall at
the Office of the Commissioners of Patents, with his Petition, on the
7th December 1864.
I, ALEXANDER DALLAS HALL, of Glasgow, in the County of Lanark, North
Britain, Gentleman, do hereby declare the nature of the said Invention of
"AN IMPROVED COMPOUND FOR COATING THE BOTTOMS OF SHIPS AND STRUCTURES,
WHOLLY OR PARTIALLY IMMERSED IN THE SEA OR TIDAL ESTUARIES, AND IN THE
SYSTEM OR MODE OF PREPARING THE SAME," to be as follows, that is to say :-
This Invention relates to a certain improved composition of elementary
substances to be used to form a viscous compound for coating or covering the
immersed portions of the hulls of ships, vessels, or boats, and it may also be
employed for coating other structures, wholly or partially immersed, for the
purpose of, as far as practicable, preventing their decay.

page_text: The ingredients employed for producing the compound, consist of certain
portions of fat, resin, vegetable and metallic matter, and these are used in
various proportions to meet the requirements of the material and structure to
which it is applied.
The compound when used is applied in a liquid state to the structure to be
coated, and the ingredients which it is preferred to employ to form it consist
of tallow or other fatty substance, the rosin of commerce, linseed, or poppy,
or other suitable oils, and zinc or copper in a state of crystallization, or salt.
The proportions of the ingredients which it is preferred to employ consist
of three parts by weight of grease, two of resin, one and a half of oil, forty
per cent. of metallic salt, and one part by weight of alkaline solution. The
tallow or grease is first liquified apart from the other ingredients; when it is
melted the oil is added, and the salt of zinc or copper previously dissolved
in water is then applied, and to thoroughly effect decomposition an alkaline
solution is added.
The viscous compound produced after the above described operations are
carried out is washed several times in water for the purpose of removing the
excess of acid, after which it is dried upon a steam pan or other suitable
apparatus, which when thoroughly carried out leaves the compound material
fit to be applied to the purposes herein-before referred to.
In some cases it is found advantageous to add to the compound siliceous
substances such as flint glass or other similarly suitable substance.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Alexander Dallas Hall in the Great Seal Patent Office
on the 6th May 1865.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, ALEXANDER
DALLAS HALL, of Glasgow, in the County of Lanark, North Britain,
Gentleman, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Seventh day of December, in the year of our Lord
One thousand eight hundred and sixty-four, in the twenty-eighth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me,
the said Alexander Dallas Hall, Her special license that I, the said Alexander
Dallas Hall, my executors, administrators, and assigns, or such others as I,
the said. Alexander Dallas Hall, my executors, administrators, or assigns,
should at any time agreo with, and no others; from time to time and at all

page_text: 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
"AN IMPROVED COMPOUND FOR COATING THE BOTTOMS OF SHIPS AND STRUCTURES;
WHOLLY OR PARTIALLY IMMERSED IN THE SEA OR TIDAL ESTUARIES, AND IN THE
SYSTEM OR MODE OF PREPARING THE SAME," upon the condition (amongst others)
that I, the said Alexander Dallas Hall, by an instrument in writing under
my hand and seal, should 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 immediately after the date of the said Letters
Patent.
NOW KNOW YE, that I, the said Alexander Dallas, Hall, 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
following statement, that is to say:-
My said Invention relates to a certain improved composition of elementary
substances to be used to form a viscous compound for coating or covering the
immersed portions of the hulls of ships, vessels, or boats, and it may also be
employed for coating other structures, wholly or partially immersed, for the
purpose of, as far as practicable, preventing their decay.
The ingredients employed for producing the compound consist of certain
portions of fat, resin, vegetable and metallic matter, and these are used in
various quantities to meet the requirements of the material and structure to
which it is applied.
The compound when used is applied in a liquid state to the structure to be
coated, and the ingredients which it is preferred to employ to form it consist
of tallow or other fatty substance, the rosin of commerce, linseed, or poppy or
other suitable oils, and copper in a state of crystallization, or salt.
In preparing the the plastic compound herein-before referred to, it is preferred
to use the substances previously specified in the following manner and pro-
portions, viz. I dissolve in an iron boiler equal parts by weight, say 1 cwt.
each of tallow or lard and rosin; when these substances are liquified, one and
a half parts by weight of vegetable oil, linseed or poppy, are added, and the
whole is exposed to further heat and agitation. The liquid compound is then
run into a leaden or other suitable vault containing water in a state of ebullition,
and half a part by weight of a salt of copper or zinc dissolved in a solution of
sulphate of soda is then added, mutual decomposition ensues, the solid mass is
then well washed in several waters and dried upon a steam or other pan, and

page_text: when these operations are completely carried out the compound material is
left in a state fit to be applied to the purposes herein-before referred to.
In some cases it is found useful to add to the compound siliceous substances,
such as flint, glass, or other similarly suitable substance.
Having now described the nature of my said Invention, and the manner in
which the same is or may be used or carried into practical effect, I would
observe in conclusion that I do not confine myself to the precise proportions
of the ingredients herein specified, as in some cases it may be advantageous
to modify them without deviating from the true principles of my Invention;
but what I consider novel and original, and therefore claim as the Invention
secured to me by the herein-before in part recited Letters Patent is, the
composition of ingredients to be applied to the bottoms of ships and other
structures, wholly or partially immersed, so as to prevent their fouling by the
adhesion thereto of animal or vegetable life, or other injurious substances, as
herein-before described.
In witness whereof, I, the said Alexander Dallas Hall, have hereunto
set my hand and seal, this Third day of May, One thousand eight
hundred and sixty-five.
ALEXANDER DALLAS HALL. (L.S.)