IMPROVEMENTS IN PROTECTING IRON SHIPS AND OTHER SUBMERGED SURFACES FROM CORROSION AND MARINE GROWTHS, AND IN COMPOSITIONS TO BE SO EMPLOYED
Year: 1868

page_text: LETTERS PATENT to Catherine MacMillan, of 27, Northumberland
Place, Sunderland, in the County of Durham, Widow, Adminis-
tratrix of the late William Jardine Combe MacMillan, for the
Invention of." IMPROVEMENTS IN PROTECTING IRON SHIPS AND OTHER
SUBMERGED SURFACES FROM CORROSION AND MARINE GROWTHS, AND IN
COMPOSITIONS TO BE SO EMPLOYED."-A communication by her late
husband, William Jardine Combe MacMillan, who died on the
5th day of March 1868, and whom she believes was the first and.
truc Inventor thereof...
PROVISIONAL SPECIFICATION left by the said Catherine MacMillan.
at the Office of the Commissioners of Patents, with her Petition, on
the 21st October 1868.
I, CATHERINE MACMILLAN, of 27, Northumberland Place, Sunderland,
in the County of Durham, Widow, Administratrix of the late William
Jardine Combe MacMillan, do hereby declare the nature of the said
Invention for "IMPROVEMENTS IN PROTECTING IRON SHIPS AND OTHER SUBMERGED.

page_text: SURFACES FROM CORROSION AND MARINE GROWTHS, AND IN COMPOSITIONS TO BE SO
EMPLOYED," to be as follows:-
This Invention has for its object improvements in protecting iron ships
and other submerged surfaces from corrosion and marine growths, and
in compositions to be so employed. For this purpose a compound of
gutta percha and resin in equal proportions is employed; these materials
are boiled together until completely incorporated with each other, and
they should be applied in the form of a coating to the surface of the ship
or other surface while hot; the surface may be heated and heated rollers
may be used to spread the composition. A composition to be placed over
the compound above mentioned is also prepared by dissolving from 3
to 4 ounces of phosphorus in about one pound of bi-sulphurct of carbon,
and mixing the solution with a solution of shellac dissolved in alcohol
until it produces a sufficiently thick varnish.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Catherine MacMillan in the Great Seal Patent
Office on the 21st April 1869.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, CATHERINE
MACMILLAN, of 27, Northumberland Street, Sunderland, in the County
of Durham, Widow, Administratrix of the late William Jardine Combe
MacMillan, send greeting.
"
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twenty-first day of October, in the
year of our Lord One thousand eight hundred and sixty-eight, in the
thirty-second year of Her reign, did, for Herself, Her heirs and suc-
cessors, give and grant unto me, the said Catherine MacMillan, Her
special licence that I, the said Catherine MacMillan, my executors,
administrators, and assigns, or such others as I, the said Catherine
MacMillan, 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 Inven-
tion for "IMPROVEMENTS IN PROTECTING IRON SHIPS AND OTHER SUBMERGED
SURFACES FROM CORROSION AND MARINE GROWTHS, AND IN COMPOSITIONS TO BE SO

page_text: EMPLOYED," a communication to me by my late husband, William Jardine
Combe MacMillan, who died on the 5th day of March 1868, and whom
I believe was the first and truc Inventor thereof, upon the condition
(amongst others) that I, the said Catherine MacMillan, 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 Catherine MacMillan, do hereby
declare the nature of the said Invention, and in what manner the same
is to be performed, to be particularly described and ascertained in and by
the following statement thereof, that is to say:
This Invention has for its object improvements in protecting iron ships
and other submerged surfaces from corrosion and marine growthis, and
in compositions to be so employed. For this purpose a compound of
gutta percha and resin in equal proportions is employed; these materials
are boiled together, using however only so much heat as is necessary to
adınit for the complete mixture of the ingredients, and they are stirred
and worked together until they are completely incorporated with cach
other. The surface of the iron ship having been thoroughly cleaned is
heated by means of a coke fire contained in a portable basket; the
compound is then applied; it should be sufficiently hot to bring it to a
plastic or semi-fluid state, and is spread upon the surface, which is
sufficiently heated to cause it readily to adhere by means of small hand
metal-spreading rollers or irons; these rollers or irons are also heated.
By these means the composition is spread over the surface so as to form
a thin coating of uniform or nearly uniform thickness, which sets on
cooling, adhering firmly to the surface, and as it contains no solvent
or volatile ingredient remains quite impervious to moisture, there being
nothing in the composition which by its evaporation can leave inter-
stices or pores by which moisture might enter. This first coating is all
that is required to prevent the corrosion of the metallic surface, but to
prevent the adhesion thereto of barnacles and marine growths I apply
over the first coating a second coating prepared by dissolving from 3 to
4 ounces of phosphorous in about one pound of bi-sulphuret of carbon,
and mixing the solution with a solution of shellac dissolved in alcohol

page_text: until it produces a sufficiently thick varnish, which I apply by means of a
brush over the first coating when this is set and hard. The phosphorus
in this composition by slowly oxidizing forms phosphoric acid, which
effectually destroys all adhering growths. The shellac when applied
as above described serves both to hold the phosphorus to the surface
to be protected and also partially to protect and cover it, nevertheless
it leaves it free slowly to oxidize with the formation of phosphoric
acid.
Having thus described the nature of the said Invention, and the
manner of performing the same, I would have it understood that what I
claim is, the improvements in protecting iron ships and other submerged
surfaces from corrosion and marine growths, and in compositions to be
so employed, substantially as above described.
In witness whereof, I, the said Catherine MacMillan, have herc-
unto set my hand and scal, this Twentieth day of April, in the
year of our Lord One thousand eight hundred and sixty-nine.
CATHERINE MACMILLAN. (L.S.)