AN IMPROVED COMPOSITION FOR COATING IRON OR OTHER VESSELS, AND FOR OTHER SIMILAR PURPOSES."
Year: 1865

page_text: LETTERS PATENT to John Cornelius Craigie Halkett, of Cramond House,
in the County of Mid Lothian, North Britain, for the Invention of "AN
IMPROVED COMPOSITION FOR COATING IRON OR OTHER VESSELS, AND FOR OTHER
SIMILAR PURPOSES."
PROVISIONAL SPECIFICATION left by the said John Cornelius Craigie
Halkett at the Office of the Commissioners of Patents, with his
Petition, on the 9th May 1865.
I, JOHN CORNELIUS CRAIGIE HALKETT, of Cramond House, in the County of
Mid Lothian, North Britain, do hereby declare the nature of the said Invention
for "AN IMPROVED COMPOSITION FOR COATING IRON OR OTHER VESSELS, AND FOR OTHER
SIMILAR PURPOSES," to be as follows:-
This improved composition which is intended to be used as an anticorrosive
and antifouling mixture for coating iron or wooden vessels, buoys, piles, piers,
or other such structures as are exposed to the deteriorating action of sea water,
consists principally in a mixture of a poisonous compound of mercury with
mineral tar or pitch, or with vegetable tar or pitch or other substance of a
bitumenous nature in combination with oxide of lead or sulphate of baryta.
Various poisonous compounds of mercury answer the purpose, but I prefer to
use either of the poisonous compounds mentioned in the Specification of
Letters Patent granted to Francis Cruickshank, dated 4th August 1864
(No. 1941). For example, the tar, pitch, or other bitumenous substance
having been previously dissolved in naphtha by boiling it therewith in a
closed vessel, I take one part by weight of the white oxide of lead or of

page_text: sulphate of baryta, and an equal part of one of the poisonous compounds of
mercury above referred to, and I mix and stir the same well with an equal
part of coal tar dissolved as above named. The mixture may be payed on
with a common brush. The above proportions may be varied as occasion
may require or experience dictate, and it will doubtless be found in practise
that a smaller proportion of the poisonous compound of mercury than that
named will be sufficient for the purpose.
SPECIFICATION in pursuance of the conditions of the Letters 'Patent, filed
by the said John Cornelius Craigie Halkett in the Great Seal Patent
Office on the 8th November 1865.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
CORNELIUS CRAIGIE HALKETT, of Cramond House, in the County of Mid
Lothian, North Britain, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Ninth day of May, in the year of our Lord One
thousand eight hundred and sixty-five, in the twenty-eighth year of Her reign,
did, for Herself, Her heirs and successors, give and grant unto me, the said
John Cornelius Craigie Halkett, Her special licence that I, the said John
Cornelius Craigie Halkett, my executors, administrators, and assigns, or such
others as I, the said John Cornelius Craigie Halkett, my executors, adminis-
trators, 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 "AN IMPROVED COMPOSITION FOR COATING IRON OR OTHER VESSELS,
AND FOR OTHER SIMILAR PURPOSES," upon the condition (amongst others) that 1,
the said John Cornelius Craigie Halkett, 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 I, the said John Cornelius Craigie Halkett, 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 an improved composition which is intended

page_text: to be used as an anticorrosive and antifouling mixture for coating iron or
wooden vessels, buoys, piles, piers, or other such structures as are exposed to
the deteriorating action of sea water, and which consists principally of a
mixture of a poisonous compound of mercury with mineral tar or pitch, or
with vegetable tar or pitch or other substance of a bituminous nature in
combination with oxide of lead or sulphate of baryta. Various poisonous
compounds of mercury answer the purpose, but I prefer to use either of the
poisonous compounds mentioned in the Specification of Letters Patent granted
to Francis Cruickshank, dated 4th August 1864 (No. 1941). For example,
the tar, pitch, or other bituminous substance baving been previously dissolved
in naphtha by boiling it therewith in a closed vessel, I take one part by
weight of the white oxide of lead or of sulphate of baryta, and an equal part
of one of the poisonous compounds of mercury above referred to, and I mix
and stir the same well with an equal part of one or more of the said bituminous
substances dissolved as above named. The mixture may be payed on with a
common brush. The above proportions may be varied as occasion may requiro
or experience dictate, and it will doubtless be found in practice that a smaller
proportion of the poisonous compound of mercury than that named will be
sufficient for the purpose.
Having thus particularly described my said Invention, and the manner in
which the same is to be performed, I have to state that what I believe to be
novel and original, and claim as secured to me by the herein-before in part
recited Letters Patent is, the making of an improved composition for coating
iron or other vessels, and for other similar purposes by mixing a poisonous
compound of mercury with mineral tar or pitch or with vegetable tar or pitch,
or other bituminous substance in combination with oxide of lead or sulphate
of baryta, substantially as herein-before described.
In witness whereof, I, the said John Cornelius Craigie Halkett, have
hereunto set my hand and seal, this Sixth day of November, in the
year of our Lord One thousand eight hundred and sixty-five.
Witness,
EDMUND HUNT,
Patent Agent,
Glasgow.
J. C. CRAIGIE HALKETT. (L.S.)