IMPROVEMENTS. IN PREVENTING CORROSION AND FOULING OF IRON SHIPS."
Year: 1866

page_text: LETTERS PATENT 'to William Peter Piggott, of 16, Argyll Street, Regent
Street, in the County of Middlesex, for the Invention of "IMPROVEMENTS.
IN PREVENTING CORROSION AND FOULING OF IRON SHIPS."

page_text: cation with the iron surfaces to be protected or preserved with a view to the
prevention of corrosion, either of the internal or external portions of iron ships;
or in lieu of zinc any other metal may be used which is electro-positive to iron.
The result obtained is that the zinc or other metal being electro-positive to
the iron will slowly corrode, whilst the negative metal or iron will be
preserved.
In order to preserve the bottoms of iron ships it is proposed to cause the
ship to be in one electrical condition, and the water in which it floats in the
opposite electrical condition, the relative electrical conditions being reversed or
changed at pleasure. The means preferred for producing the result named
consists either in using the sea as a battery by causing it to flow through à
chamber containing zinc and graphite inside the ship, or in erecting in the
interior of the ship itself the peculiar battery described in the Specification of
a Patent granted to me on or about the 28th of August 1865, No. 2213, one
end or pole of 'such battery being in communication with the iron of the ship
and the other with the sea.
By the means above described operating conjointly upon an iron ship it is
obvious that the iron will not only be preserved but at the same time will be
kept clean, and this without the expensive process of painting or coating as
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said William Peter Piggott in the Great Seal Patent Office on
the 27th October. 1866.
19. 11:
TO ALL TO: WHOM THESE. PRESENTS SHALL COME,. I, WILLIAM
PETER PIGGOTT, of 16, Argyll Street, Regent Street, in the 'County of
Middlesex, send greeting.
C. WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-eighth day of April, in the year of our Lord
One thousand eight hundred and sixty-six, in the twenty-ninth year of Her
reign did, for Herself, Her heirs and successors, give and grant unto me, the s
shid William Peter Piggott, Her special license that I, the said William
Peter Piggott, my executors, administrators, and assigns, or such others as I,
the said William Peter Piggott, my executors, administrators, or assigns,
should at any time agree 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 "In-
PROVEMENTS. IN PREVENTING CORROSION AND FOULING OF IRON SHIPS," upon the
condition (amongst others) that I, the said William Peter Piggott, my,
executors or administrators,, by an instrument in writing under my hand and
seal, should particularly describe and ascertain, the nature of the said Inven-
tion, 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 Patenta...
.
I
NOW KNOW YE, that I, the said William Peter Piggott, 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:-
"
The My said Invention relates to certain peculiar means for preventing the,
corrosion.and fouling of iron ships or ships; clad with iron without the aid of
paints or other protective coatings, and consists in the application to such
purposes of voltaic electricity. In order to prevent the corrosion.of the internal
and external portions of iron, ships, resulting from the action of sea water
thereon I cause a galvanic action to be established between the iron of the
ship and some "other, metal which is electro-positive
iron (by preference
zinc) and make use of, the sea water for exciting the battery thus formed.
The result is; that the zine or electro-positive metal will be slowly corroded
or decomposed whilst the iron which is. electro-negative will be preserved.
In carrying out this part of my dnvention I take one or more plates, strips,
bars, or blocks of zinc, 'and attach them either directly to the iron surface of
the ship, or place 'them, in electrical communication therewith by the aid of
suitable conductors, in which latter case the zinc need not be in actual contact
with the iron, but in all cases the zino should be so situate as to enable it to
be acted upon by the sea water. I prefer to use it in the form of one or more
bars or strips secured directly to the sides of the ship below the water line, or
secured along the keel, or to the stem or stern post or other convenient part
of the ship. I also propose to insert pieces, of zinc or other metal which is
electro-positive to iron in the brick or cement lining of iron ships, so as to be
in direct metallic contact with the iron; or the zinc-may be in electrical com-
munication, by means of conductors with the inside or outside of the ship, in I
which case a battery will be formed, the bilge water serving as the exciting i

page_text: solution. Dy these pe care
---
& PIRLA
protecting the iron surfaces from the corroding action of the sea water ist
obviated.
In order to prevent the fouling of iron ships by the adhesion of marine
plants and animals thereto, I place the ship by the aid of battery currents.in
one electrical condition and the water in which it floats in the opposite
electrical condition by the aid of conductors from either end. of the battery
leading into the water, the iron of the 'ship being at the same time connected
with the opposite pole of the battery, the relative electrical conditions being
reserved or changed from time to time nt pleasure.
In carrying out this part of my Invention I place a plate or strip of zinc
down 'the stern post and another down the stem or cutwater, both of which
should be insulated from the iron of the ship. By the arrangement of one
or more ordinary batteries in the ship, or by an arrangement of battery.
wherein the sea water itself is used as the exciting medium, 1 cause two
separate currents of electricity to flow in opposite directions by the aid of
suitable insulated conductors from the zinc at one end of the ship through 'the
sea water to the iron at the other end, the effect of which is not only to keep
the bottom of the ship free from marine plants and animals; but also to
negative its polar influence upon the compass, which is most important
advantage in iron ships: Any ordinary galvanic battery may be employed in
conjunction with the said insulated plates or strips of zinc; or the peculiar
battery may be used which I have described in the Specification of my Patent
bearing date the Twenty-eighth of August, One thousand eight hundred and
sixty-five, No. 2213. When the sea is used as the exciting agent of the
battery I construct a porous or perforated cell or chamber at each end or in
any convenient part of the ship below the water line so that the sea can have
free access thereto. This porous or perforated chamber is to be lined with
any suitable insulating material, and is to contain a plate of zinc. or other
élenient which is electro-positive to iron, which element should be in electrical
communication with the iron in order to close the electric circuit; by employing
a similar cell-containing a block of carbon as well as a plate of zinc, and by
connecting the iron of the ship alternately with the zine -and the carbon, the
currents will be reversed.
.
Having now described and particularly ascertained the nature of my said
Invention, and the manner in which the same is or may be used or carried
into effect, I would observe in conclusion that what I consider to be novel
"

page_text: and original, and therefore claim as the Invention secured to me by the herein-
before in part recited Letters Patent is, the system or mode of preserving
iron ships from corrosion and preventing the fouling of the bottoms of such
ships by the application and use of voltaic electricity, substantially as herein-
before described.
In witness whereof, I, the said William Peter Piggott, have to this my
Specification hereunto set my hand and seal, this Twenty-sixth day
of October, One thousand eight hundred and sixty-six.
WILLIAM PETER PIGGOTT. (L.B.)
WILLIAM PETER PIGGOTT. (L.B.)