IMPROVEMENTS IN COATINGS FOR THE PREVENTION OF THE FOULING OF THE BOTTOMS OF IRON AND OTHER SHIPS
Year: 1864

page_text: LETTERS PATENT to Francis Cruickshank, of Edinburgh, in the County
of Mid Lothian, North Britain, for the Invention of "IMPROVEMENTS IN
COATINGS FOR THE PREVENTION OF THE FOULING OF THE BOTTOMS OF IRON
AND OTHER SHIPS."
Sealed the 31st January 1865, and dated the 4th August 1864.
PROVISIONAL SPECIFICATION left by the said Francis Cruickshank at
the Office of the Commissioners of Patents, with his Petition, on the
4th August 1864.
I, FRANCIS CRUICKSHANK, of Edinburgh, in the County of Mid Lothian,
North Britain, do hereby declare the nature of the said Invention of "IMPROVE-
MENTS IN COATINGS FOR THE PREVENTION OF THE FOULING OF THE BOTTOMS OF IRON.
AND OTHER SHIPS," to be as follows, that is to say :-
This Invention relates to the prevention of the fouling of the bottoms of
iron and other ships, and consists in incorporating in the coatings employed
for that purpose one or more of the following mercurial compounds, namely,
red oxide of mercury, sometimes called nitric oxide of mercury, oxychloride of
mercury, and white precipitate of mercury, the substance produced by the
action of ammonia upon solutions of the salts of mercury.
In practising the Invention, a coating of boiled linseed oil is first applied
to the cleaned surface of the ship's bottom; there is then applied a second
coating consisting of the mercurial compound mixed or prepared with boiled
linseed oil, and having added to it a solution of gutta percha or rubber in

page_text: turpentine, naphtha, or the like, such solution being of a creamy consistency.
From two to five ounces of the mercurial compound, exclusive of the medium,
will be required for every square yard of surface to be coated. It is advan
tageous to apply a third or final coating of boiled linseed oil. The media
mentioned are preferred, but the essential ingredient in the coatings is the
mercurial compound.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Francis Cruickshank in the Great Seal Patent Office on the
4th February 1865.
TO ALL TO WHOM THESE PRESENTS SHALL COME, J, FRANCIS
CRUICKSHANK, of Edinburgb, in the County of Mid Lothian, North Britain,
send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Fourth day of August, 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
Francis Cruickshank, Her especial licence, that I, the said Francis Cruick-
shank, my executors, administrators, and assigns, or such others as I, the said
Francis Cruickshank, my executors, administrators, and assigns, should at any
time agree with and no others, from time to time, and at all 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 "IMPROVEMENTS IN
COATINGS FOR THE PREVENTION OF THE FOULING OF THE BOTTOMS OF IRON AND
OTHER SHIPS," upon the condition (amongst others) that I, the said Francis
Cruickshank, my executors or administrators, by an instrument in writing
under my, or their, or one of their hands and seals, 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 Ị, the said Francis Cruickshank, 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 in writing, that is to say:-
My said Invention relates to the prevention of the fouling of the bottoms of

page_text: iron and other ships by means of one or more of the following mercurial com-
pounds made up or incorporated with a suitable medium to form a coating or
paint to be applied to the surface to be protected. The mercurial compounds
referred to are, 1, red oxide of mercury; 2, white precipitate of mercury,
the substance specified in the British Pharmacopæia as "Hydrargyrum
ammoniatum;" and, 3, oxychloride of mercury, or any of the various definite
chemical compounds of corrosive sublimate and protoxide of mercury included
under that designation.
The medium with which the mercurial compound is incorporated may be
varied, provided that it is of a resinous or or oleaginous, but not of a saponaceous
character; and whereas at the time of applying for the herein-before in part
iccited Letters Patent, I preferred a medium consisting of boiled linseed oil
mixed with a solution of gutta percha or rubber, as stated in my Provisional
Specification, I have since ascertained that a better medium may be prepared
in the manner herein-after stated.
And in order that my said Invention, and the manner of performing the
same, may be properly understood, I will now particularly describe what I at
present believe to be the best way of preparing and applying my improved
anti-fouling coating.
I take one gallon of a solution of rosin in turpentine (made by dissolving
with the aid of heat ten pounds by weight of rosin in one and a half gallons
of turpentine) and mix it with half a gallon of a solution of gutta percha
(made by dissolving, with the aid of heat, four pounds of gutta percha in one
gallon of turpentine). To each gallon of the compound obtained by mixing
these two fluids I add five and three quarter pounds of any one or more of the
mercurial compounds, herein-before mentioned, and having thoroughly incor-
porated it with the fluid, I add an equal weight, namely, five and three-
quarter pounds of a suitable substance, such, for example, as red oxide of lead,
for the purpose of giving it due consistency; the whole is then thoroughly
mixed. Thus prepared, the mixture may be applied directly as a coating to
the vessel, or if necessary it may be rendered more fluid by the addition of a
small quantity of turpentine.
Although I believe the proportions of the ingredients, and the manner of
applying my improved coating, herein-before detailed, to be the most suitable
in practice, I do not restrict myself thereto, as they may be varied within
reasonable limits without injury; whilst the mercurial compounds, herein-
before mentioned, may be mixed with any resinous or oleaginous, but not
saponaceous medium, such, for example, as is or may be used for prevent-
ing the corrosion of ships' bottoms; but what I claim as the Invention

page_text: secured to me by the herein-before in part recited Letters Patent is, the
preparing of coatings with the mercurial compounds herein-before mentioned,
and in the manner herein-before described, to be used for the prevention of
the fouling of the bottoms of iron and other ships.
In witness whereof, I, the said Francis Cruickshank, have hereunto set
my hand and seal, this Thirtieth day of January, in the year of our
Lord One thousand eight hundred and sixty-five.
Witness,
FRANCIS CRUICKSHANK. (L.S.)
EDMUND HUNT,
Patent Agent,
28, St. Enoch Square,
Glasgow.