AN IMPROVED PROCESS FOR PRESERVING IRON-PLATED AND OTHER VESSELS AND METALLIC ARTICLES FROM OXIDATION AND PREVENTING SHIPS BOTTOMS FROM FOULING
Year: 1862

page_text: LETTERS PATENT to Jean Pierre Jouvin, of Rochefort s./Mer, in
France, Chief Medical Officer of the Imperial Navy, and Professor
of Chemistry to the Naval School of Medicine at Rochefort, for the
Invention of "AN IMPROVED PROCESS FOR PRESERVING IRON-PLATED AND
OTHER VESSELS AND METALLIC ARTICLES FROM OXIDATION AND PREVENTING
SHIPS BOTTOMS FROM FOULING."
Sealed the 31st October 1862, and dated the 15th May 1862.
PROVISIONAL SPECIFICATION left by the said Jean Pierro Jouvin, at
the Office of the Commissioners of Patents, with his Petition, on the
15th May 1862.
I, JEAN PIERRE JOUVIN, of Rochefort s./Mer, in France, Chief Medical
Officer of the Imperial Navy, and Professor of Chemistry to the Naval
School of Medicine at Rochefort, do hereby declare the nature of my
Invention of "AN IMPROVED PROCESS FOR PRESERVING IRON-PLATED AND OTHER
VESSELS AND METALLIC ARTICLES FROM OXIDATION, AND PREVENTING SHIPS BOTTOMS
FROM FOULING," to be as follows, that is to say: -
To carry out the first part of my Invention for preserving armour plated
and other vessels and metallic articles from oxidation, I apply sheets of zinc
on the inner surface of the plates or sheets of iron employed for armour-
plated or iron vessels, and zinc in the form of paint on all the parts where
sheet zinc cannot be applied; I also apply zinc paint upon sheet iron, water
tanks, and marine steam boilers, and upon metallic articles, for which paint
with a base of red lead is now employed.

page_text: To carry out the second part of my Invention for preventing the deposit of
sea weeds and barnacles I employ a compound consisting of fifty-five parts
of basic sulphate of mercury (HGO³) SO³, and forty-five parts of ferroso-
ferric cyanide or prussian blue (Fe Cy)³ + 2 Fe Cy³. To apply this com
pound with advantage I first cleanse the iron as completely as possible, then
cover it with a thick coating of paint formed of metallic zine, and allow it to
dry thoroughly; I then apply thereon a coat of paint composed of red lead,
with nine per cent. of the above-stated compound, the red lead may be re-
placed by any other substance having the same covering and adhering
properties.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Jean Pierre Jouvin in the Great Seal Patent Office on
the 13th November 1862.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, PIERRE
JOUVIN, of Rochefort-sur-Mer, in France, Chief Medical Officer of the
Imperial Navy and Professor of Chemistry to the Naval School of Medicine
at Rochefort, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Fifteenth day of May, in the year of our Lord
One thousand eight hundred and sixty-two, in the twenty-fifth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me,
the said Pierre Jouvin, Her special license that I, the said Pierre
Jouvin, my executors, administrators, and assigns, or such others as I, the
said Pierre Jouvin, 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
"AN IMPROVED PROCESS FOR PRESERVING IRON-PLATED AND OTHER VESSELS AND
METALLIC ARTICLES FROM OXYDATION, AND PREVENTING SHIPS' BOTTOMS FROM
FOULING," upon the condition (amongst others) that I, the said Pierre Jouvin,
my executors or administrators, by an instrument in writing under my, or their,
or one of their hands or seals, should particularly describe and ascertain the
nature of the said Invention, and in what manner the same was to be per-
formed, 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.

page_text: NOW KNOW YE, that I, the said Pierre Jouvin, do bereby 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 :-
For preserving iron ships from oxydation by the action of sea water, my
process consists in lining the inner surface of ships" sides and bottoms, per-
fectly scoured with sheets or lamina of zine applied directly against the
sheet iron, and there held fast between the latter and the frames. But as
iron ships now afloat present some difficulty to the application of such zinc
sheathing in the interior of their holds, I first scour with care the internal
sides of the hold, and afterwards I apply thereon a double coat of a paint made
of powdered metallic zinc, which I spread all over from the keel up to a little
above the water line. As zinc paint, on account of the fatty matter it con-
tains, does not act as an electric protector with the same efficiency as zinc
when employed in the form of sheets, it is necessary to increase the area of the
protecting surface.
For iron ships on the stocks, as soon as the keel, the stem, the stern post
and frame are set up they receive a thick layer of the aforesaid metallic
zinc paint. The boarding of the keel and sides is afterwards proceeded with
as usual, care being taken to apply underneath the timber employed a coat of
the same paint, or in lieu thereof sheets of greasy felt thickly sprinkled with
powdered metallic zinc. The, zinc sheets are then applied without difficulty,
and become bound with the sheets of iron of the streaks from the keel up to.
the water line, and from the stem to the stern post so as to form part with
them. The sheets of zinc are held between the sheets of iron which form
the stem and the keel, and, assuming the shape of the sheets to be protected
form continuous bands extending right and left and from the bottom upwards,.
so as to meet again and join each other, between the sheet iron forming the
stern post, and to have their ends in the vicinity of the helm and the water.
line. As the rivetting takes place at a temperature higher than that of the
melting of zinc, and approaching that at which this metal evaporates, part of
the sheets around the heads of the rivets would be destroyed; to avoid this
defect, the sheets of zinc must be of a sufficient breadth and length to cover
the sheet iron to within one-third of an inch of the rivets, without reaching
them. Thus the phenomenon of dilatation could, therefore, freely take place
on the preserving plates, the co-efficient of expansibility of these plates being
nearly double that of iron.
For those parts of the zinc plates held between the frames and the sheet
iron, in order to insure a complete rivetting of iron on iron, it will be

page_text: necessary to begin by cutting wasbers or discs, by the ordinary means in these
bands opposite each hole of the rivets. The diameter of these washers must
be double that of the rivets, and they are finally replaced by rings of sheet
iron, the diameter and thickness of which being equal to that of the bands of
zinc. The covering bands & the heads of the rivets must receive a thick
coat of metallic zinc paint. In the electro chemical scale, the protecting
metal (zinc) coming immediately after the protected metal (iron) it will be
advantageous to have the protecting surface as nearly as possible of the same
dimensions as those of the surface to be protected. However, having
economy in view, I have found that the protecting bands of zinc, if properly
fixed from the keel up to the water line, may be only about two-thirds at
maximum, and about one-tenth at minimum of the last surface, provided all
the spaces between the zine bands be covered with the aforesaid metallic zine
paint. The zinc sheets should measure about one-fourteenth of an inch in
thickness for the lower part, and about one-twenty-eighth of an inch for the
sides of the hold. When the ship is built all the parts of iron composing the
hold, such as the ribs, keelsons, clamps, transversal bulk heads and others not
covered by the zinc bands, are carefully scoured, brushed, or otherwise cleaned
and then coated with metallic zinc paint.
To protect the exterior part of the hull immersed from the deposit of
marine shells and plants, I proceed as follows:-From my chemical researches
it is certain that trimercuric sulphate or turbith mineral (SO³ 3HgO)
mixed with Prussian blue (3Fe Cy + 2Fe² Cy³) produces by its contact
with the alkaline chlorides of sea water, one of the most violent poisons known
to mineral chemistry, videlicet, the mercuric cyanide (Hg Cy) in the shape
of chloro-cyanide of mercury and sodium. I therefore first mix fifty-five
parts of turbith mineral with forty-five parts of Prussian blue of the com-
monest tint, but not adulterated, so as to obtain a green powder perfectly
homogeneous, and I compose the poisonous paint as follows:-Of boiled linseed
oil, two hundred and fifty parts; red lead (or any other agent which may
cover or adhere as well or better than red lead), which is here used as a
mere vehicle for the poisonous.compound, six hundred and fifty to six hundred
and sixty parts; the herein-before described mixture, ninety to one hundred
parts. These substances must be well ground together in order to effect an
uniform and complete distribution of the poisonous compound throughout the
mass of the paint. But as iron possesses the property of reducing mercurial
and leaden compounds, this preparation must not be applied direct on the bare
metal, all the parts of the hull, videlicet, the sheet iron of the keel, cut water,
rudder, paddle-wheel frames, and every part of iron to be immersed or wetted,

page_text: must be previously coated with two layers of the metallic zinc paint, after
being scoured as completely as possible. When these layers of metallic zinc
paint are quite dry, the poisonous compound or paint is applied thereon.
This poisonous compound may prove also very advantageous if applied to
wood employed to secure dikes, embankments, and for marine constructions
to protect them from injury by teredos. The smallest particle of the chloro-
cyanide of mercury and sodium produced by its contact with sea salt suffices
to kill instantaneously animalculæ, plants, and even their germs when brought
within its influence.
To apply my Invention to iron-plated vessels I place either between the
woodwork of the hull and each iron plate a sheet of zinc the surface of which
is rather smaller than that of the iron plate, or I first coat this woodwork
with a thick layer of metallic zinc paint, then cach iron plate previously well
scoured, is similarly painted on its inner face and adapted to the sides of the
ship, the ship being finished, the whole of her bottom to be immersed in
water, is treated in the manner before-described, that is to say, first coated
with a double layer of metallic zine paint, and afterwards with the poisonous
compound paint. To preserve sheet iron tanks, marine boilers, steam
engines, and other similar articles from oxydation, I either apply on them,
that is to say, externally, zinc sheets, or I coat them with a double layer of the
afore-mentioned metallic zinc paint.
To preserve the parts of cables and chains stored in wells, where they are
oxydized very rapidly, I apply on each of the rings or links a band of zinc
fastened by screws. I apply the metallic zinc paint to iron articles in general,
wherever red-lead paint is now made use of and as a substitute therefor.
For ships' bottoms with a copper sheathing, before the sheathing is applied, I
coat the woodwork over with a thick layer of metallic zinc paint. But
in the present case it is more economical to employ powdered cast iron, or, in
preference, iron powder, instead of zinc powder, to prepare the metallic pro-
tecting paint, as it will protect copper as effectually. Should it be found,
however, that the copper sheathing gets foul with barnacles and sea weeds it
must be coated with the poisonous compound before-mentioned.
And having now described my Invention, and the best mode I am
acquainted with for putting the same into effect, I wish it to be understood that
I do not confine myself to the precise details of the various operations, nor to
the proportion herein laid down, as the same may be altered without departing
from the principle of my Invention, which is exclusively an electro-chemical
one. But what I do claim and wish to be protected is,―
First, the applying and the mode of applying to the interior surface of iron

page_text: and iron-plated ships, zinc sheets, either alone or together with metallic zinc
paint, or felt sprinkled with metallic zinc powder, to preserve iron plated and
other ships from the destructive action of sea water, as herein-before
described.
Secondly, the production of a poisonous compound and its application to the
bottoms of iron and iron plated ships, and to wood used to construct dikes,
embankments, docks, and for naval and other similar constructions, in order
to prevent for the former the deposit of barnacles and sea weeds, and to
protect the latter from injury from teredos, as hereiu-before described.
Thirdly, the application to parts of iron ships and to iron articles of a paint
having pulverised metallic zinc for base, applicable as a substitute for red lead
paint, as herein-before described.
Fourthly, the application of sheets of zinc or metallic zinc paint to the
exterior of sheet iron tanks, marine boilers, steam engines, and other like
articles, and the application of bands of zinc to parts of cables and chains, as
herein-before described.
Fifthly, the application to the hulls of copper sheathed wooden vessels, of
protecting paint which, for economy may be made with cast iron or. iron
powder instead of zinc powder, as herein-before described.
In witness whereof I, the said Pierre Jouvin, have hereunto set my
hand and seal, this Ninth day of November, in the year of our Lord
One thousand eight hundred and sixty-two.
PIERRE A JOUVIN
(L.S.)
Chief Medical Officer, I.F.N.