IMPROVEMENTS IN THE MODE OF APPLYING METAL SHEATHING TO IRON SHIPS, CAISSONS, AND Dr Deane " FLOATING Decme, AND OTHER IRON CONSTRUCTIONS SUBJECT TO CAR PROVISIONAL SPECIFICATION
Year: 1867

page_text: LETTERS PATENT to William Day, of Westwood Park, Forest Hill, in the
County of Surrey, Gentleman, for the Invention of "IMPROVEMENTS IN
THE MODE OF APPLYING METAL SHEATHING TO IRON SHIPS, CAISSONS, AND
Dr Deane
"
FLOATING Decme,
AND OTHER IRON CONSTRUCTIONS SUBJECT TO
CAR
PROVISIONAL SPECIFICATION left by the said William Day at the
Office of the Commissioners of Patents, with his Petition, on the 4th
July 1867.
I, WILLIAM DAY, of Westwood Park, Forest Hill, in the County of Surrey,
Gentleman, do hereby declare the nature of the said Invention for "IMPROVE-
MENTS IN THE MODE OF APPLYING METAL SHEATHING TO IRON SHIPS, CAISSONS,
AND FLOATING DOCKS, AND OTHER IRON CONSTRUCTIONS SUBJECT TO CORROSION," to be
as follows:-
My Invention has for its object the protection of the plates and the
rendering of the iron of which such plates are composed impervious to
corrosion and fouling by mechanical and galvanic means, and consists in the
mode herein-after stated of applying sheathing composed of zinc. or other
suitable metal to the iron skin or armour plates of ships, caissons, floating
docks, and other iron constructions subject to like corrosion, so as to combine
when immersed or in contact with water. or partly so the electro-positive
action of the zinc or other suitable metal in preventing fouling with the

page_text: .
electro-negative condition of the iron, thereby preventing corrosion. For
this purpose the iron to which the sheathing is intended to be applied is
first partly drilled with the required numbers of holes, then screw threads are
cut or formed in the metal around such holes, thereby forming internal
screws therein. The plates of zinc or other suitable metal after being
punched and countersunk so as to correspond with the said holes are applied
to the iron, and screws of iron, zinc, or other suitable metal (but by pre-
ference of iron) are inserted and serewed in. Or instead of screws, rivets
(by preference of iron) may be employed for the purpose of fixing the
sheathing to the iron after the same has been partly drilled as required with
holes widening inwards, and the zinc or other metal sheathing has been
correspondingly punched and countersunk. By this means the sheathing
of zinc or other metal is applied securely to the iron required to be protected
in such a manner as to dispense with the need of intervening strips of iron
or other material inserted and fixed between the sheathing and the iron for
the purpose of carrying the said sheathing, and also to bring the zinc or
other electro-positive metal in contact with the iron in order to obtain the
galvanic action required. The zinc or other suitable metal is thus applied
to the iron plates of ships, caissons, floating docks, or other iron constructions
subject to corrosion in such a manner as to partly cover the outer surface
of such plates, leaving portions of the same uncovered.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said William Day in the Great Seal Patent Office on the 20th
December 1867.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
DAY, of Westwood Park, Forest Hill, in the County of Surrey, Gentleman,
send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Fourth day of July, in the year of our Lord One
thousand eight hundred and sixty-seven, in the thirty-first year of Her reign
did, for Herself, Her heirs and successors, give and grant unto me, the said
William Day, Her special licence that I, the said William Day, my executors,
administrators, and assigns, or such others as I, the said William Day,
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

page_text: 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 THE MODE OF
APPLYING METAL SHEATHING TO IRON SHIPS, CAISSONS, AND FLOATING DOCKS AND
OTHER IRON CONSTRUCTIONS SUBJECT TO CORROSION," upon the condition (amongst
others). that I, the said William Day, 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 William Day, do hereby declare
the nature of my said Invention, and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following
statement (that is to say) :-
"
My Invention of "Improvements in the Mode of Applying Metal Sheath-
ing to Iron Ships, Caissons, and Floating Docks," and other Iron Constructions
subject to Corrosion" has for its object the protection of the plates and the
rendering of the iron of which such plates are composed impervious to
corrosion and fouling by mechanical and galvanic means. Heretofore
various attempts have been made to employ zinc plates or sheets as sheathing
for ships, but such attempts have not been successful, owing to the expense-
necessarily incurred in the method hitherto used for attaching the zinc plates,
and in the complicated system of fastening that has been adopted.
My Invention consists in a very simple and economical mode of fastening.
and applying sheathing composed of zinc to the iron skin or armour plates of
ships, caissons, floating docks, and other iron constructions subject to like.
corrosion, so as to combine when immersed or in contact with water or
partly so, the electro-positive action of the zinc in preventing fouling with
the electro-negative condition of the iron, thereby preventing corrosion. The
metal which I have found most beneficial is zinc, but other metals which are
electro-positive in relation to iron may be used if they can be employed.
with a due regard to economy; copper being a metal which is electro-
negative in regard to iron, would, like other metals similarly electro-negative,
destroy the iron.
. In carrying out my Invention the iron to which the sheathing is intended..
to be applied is first partly drilled with the required number of holes, then.
screw threads are cut or formed in the metal around such holes, thereby,

page_text: forming internal screws thereon. The plates of zinc or other suitable metal
after being punched and countersunk so as to correspond with the said holes
are applied to the iron and laid on in strips from stem to stern. Such strips
may be of the width of twelve inches or thereabouts, leaving a space of six
inches between each strip; but the width of the strips and of the space
between them may be varied, so long as the zinc or other electro-positive
metal is applied to the iron in such a manner as to ensure the required
galvanic action. Screws of. iron are inserted in the said plates of zinc or
other suitable metal and screwed in. Although iron screws are preferable,
the screws may be made of zinc or other suitable metal, or instead of screws
rivets may be employed for the purpose of fixing the sheathing to the iron
after the same has been partly drilled as required with boles widening inwards,
and the zinc or other metal sheathing has been correspondingly punched and
countersunk. By this means the sheathing of zinc or other suitable metal
is applied securely to the iron required to be protected in such a manner as
to dispense with the need of intervening strips of iron or other material
inserted and fixed between the sheathing and the iron for the purpose of
carrying the said sheathing, and also to bring the zinc or other electro-positive
metal in contact with the iron in order to obtain in a most advantageous
manner the galvanic action required. In applying the zine metal sheets as
sheathing in the manner adopted by me it will be found that a considerable
saving.is effected, as it will not be found necessary to cover all the parts of
the iron, but projecting parts which it would be inconvenient or expensive
to cover with the zinc sheathing may be left uncovered, as sufficient galvanic
action will take place between the zinc and iron in the covered parts to
protect from corrosion the parts of the iron left uncovered, a. result which
has not been attained by any system of sheathing iron with zinc or other
electro-negative metal heretofore attempted to be used. The zinc or other
suitable metal is applied in the manner above described to the iron plates of
ships, caissons, floating docks, or other iron constructions subject to corrosion
in such a manner as to partly cover the outside surface of such plates, leaving
portions of the same uncovered.
Having thus described the nature of the said Invention, and the manner
of carrying the same into effect, I hereby declare that. I claim as my Inven-
tion the mode herein-before described of putting zinc or other electro-positive
metal in strips with screws or rivets of iron, zinc, or other suitable metal
upon iron ships, caissons, floating docks, and other constructions subject to
like corrosion, so as by the above-described mechanical and galvanic means

page_text: to combine when immersed or partly so the electro-positive action of the zinc,
or other suitable metal in preventing fouling with the electro-negative
condition of the iron, thereby preventing corrosion.
In 'witness whereof, I, the said William Day, have hereunto set my
hand and seal, the Fourteenth day of December, in the year of our
Lord One thousand eight hundred and sixty-seven.
Witness,
G. W. R. WAINWRIGHT,
Staple Inn,
Sol.
WILLIAM DAY. (L.S.)