IMPROVEMENTS IN PRESERVING AND PROTECTING SHIPS' SHEATHING AND OTHER METAL SURFACES EXPOSED TO THE ACTION OF SEA WATER
Year: 1872

page_text: LETTERS PATENT to Michael Henry, of Fleet Chambers, 68, Fleet
Street, in the City of London, Patent Agent, for the Invention of
"IMPROVEMENTS IN PRESERVING AND PROTECTING SHIPS' SHEATHING AND
OTHER METAL SURFACES EXPOSED TO THE ACTION OF SEA WATER."―A
communication from abroad by Michel Leon Ehrmann, of 17,
Boulevart Saint Martin, Paris, France.
Sealed the 2nd May 1873, and dated the 6th December 1872.
PROVISIONAL SPECIFICATION left by the said Michael Henry at the
Office of the Commissioners of Patents, with his Petition, on the
6th December 1872.
I, MICHAEL HENRY, of Fleet Chambers, 68, Fleet Street, in the City
of London, Patent Agent, do hereby declare the nature of the said In-
vention for "IMPROVEMENTS IN PRESERVING AND PROTECTING SHIPS' SHEATHING
AND OTHER METAL SURFACES EXPOSED TO THE ACTION OF SEA WATER," com-
municated to me from abroad by Michel Leon Ehrmann, of 17,
Boulevart Saint Martin, Paris, France, to be as follows:—
The object of the Invention is to protect metal sheathing and
armour plating of ships and other vessels, also other metal surfaces

page_text: from decomposition, fouling, barnacles, and generally from the action of
sea water. This object is effected according to this Invention by the
use of magneto-electric machines, either with direct continuous currents,
or with alternating or intermittent currents with or without com-
mutators, communication being effected between the sheathing or
surface and the machine so as to produce the required amount of
electricity or electric or electro-magnetic action.
I proceed to describe one mode of carrying out the Invention. Sup-
pose a ship's upper sheathing to be iron and its lower sheathing copper,
the copper is connected with one pole of the magneto-electric machine, 1
and the iron with the other pole, and a current is produced, which
may be reversed from positive to negative, or vice versa, being either
continuous or intermittent.
The metal in connection with the positive pole will undergo a slight
dissolving or decomposing action from the alkaline salts of the sea, but 1
this will be spread over the whole surface instead of being at the seams
and joints, and the surface will be protected from fouling barnacles and
like incrustations. The currents may be reversed, changing the con-
ductors in contact with the polar surfaces.
The magneto-electric machines may be employed by night for pro- 1
ducing an electric light.
If the sheathing be wholly iron or copper it may be connected with
one pole, the other pole being connected with rods or chains which dip
into the sea, and are insulated from the main mass of the metal. If the
sheathing be half copper and half iron it may be connected with one
nole the other nole being connooted with such noda

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Michael Henry in the Great Seal Patent Office on
the 6th June 1873.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, MICHAEL
HENRY, of Fleet Chambers, 68, Fleet Street, in the City of London,
Patent Agent, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Sixth day of December, in the year of our Lord
One thousand eight hundred and seventy-two, in the thirty-sixth year
of Her reign, did, for Herself, Her heirs and successors, give and grant
unto me, the said Michael Henry, Her special license that I, the said
Michael Henry, my executors, administrators, and assigns, or such others
as I, the said Michael Henry, 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 "IMPROVEMENTS IN PRESERVING AND PROTECTING
SHIPS'. SHEATHING AND OTHER METAL SURFACES EXPOSED TO THE ACTION OF SEA
WATER," communicated to me from abroad by Michel Leon Ehrmann,
of 17, Boulevart Saint Martin, Paris, France, upon the condition
(amongst others) that I, the said Michael Henry, my executors or admi-
nistrators, 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 Michael Henry, 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, as communicated to me, that is to
say:
-
The object of the Invention is to protect the metal sheathing and
armour plating of ships and other vessels, also other metal surfaces

page_text: exposed to the action of sea water from decomposition, fouling, barnacles,
and generally from the action of such sea water. This object is effected.
according to this Invention by the use of magneto-electric machines,.
either with direct continuous currents, or with alternating or intermittent
currents with or without commutators, communication being effected 5
between the sheathing plating or metal surface and the magneto-electric
machine so as to produce the required amount of electricity or electro-
magnetic action.
I proceed to describe one mode of carrying out the Invention. Suppose
a ship's upper or outer sheathing to be iron, and its under or inner 1
sheathing copper. The copper is connected with one pole of the
magneto-electric machine and the iron with the other pole, and a
current is produced, which may be reversed from positive to negative, or
vice versa, being either continuous or intermittent.
The metal in connection with the positive pole will undergo a slight 1
dissolving or decomposing action from the alkaline salts of the sea, but
this will be spread over the whole surface instead of being at the seams
and joints only, and the surface will be protected from fouling and
barnacles and like incrustations. The currents may be reversed by
changing or reversing the conductors in contact with the polar surfaces. 2
The magneto-electric machines may be employed by night for pro-
ducing an electric light.
If the sheathing or plating be wholly iron or wholly copper it may be
connected with one pole of the magneto-electric machine, the other pole
being connected with rods or chains which dip into the sea, and are
insulated from the main mass of the metal. If the sheathing or plating
be half copper and half iron it may be connected with one pole, the
other pole being connected with such rods or chains.
Accumulators or secondary batteries may be used to get quantity or
powerful currents.
In explaining the improvements the Inventor states that it is well known
that when two metals are used in combination in the sheathing and
armour plates of ships, such for instance as copper and zinc, copper and
iron, alloys, copper, and tin, a prejudical electric or galvanic action ensues.
The oxydizable metal becomes destroyed, and according to Becquerel

page_text: means should be taken to supply the waste or deterioration of metal as
fast as it occurs. The researches of celebrated chemists, such as Davy
and Becquerel, shew that the electric condition of the metallic surface is
the main point to be dealt with. The Inventor considers that the
modes proposed for the purpose by Davy, and by the employment of
induction batteries are not expedient, as they are troublesome and
expensive.
The alternating current machines, with or without commutators or
current changers, such as the "Alliance" and "Wild's," and constant
or continuous current machines, such as Grammé's, are among those
suitable for carrying out the Invention.
In the mode of performing the Invention above described the metal
surface in communication with the positive pole will undergo a slight
and slow dissolving action from the sea water, which affects the whole
surface (instead of only certain parts, such as the edges of plates, the
bolts, &c.), so that the wear is scarcely perceptible, and the deposit of
calcareous incrustations, sea weed, & shells is prevented. The metal
or surface in communication with the other pole will be preserved, but
shells, &c., may become attached to it; but by reversing the current,
which can be done by changing or reversing the conductors in contact
with the polar surfaces of the magneto-electric machine (rendering the
positive surface negative and vice versa) the whole surface will be kept
clean and clear. The current may be reversed as often and as rapidly as
desired.
The electric action is not likely to affect the compass, but if it should
deviate this can be remedied by the ordinary mode of compensation, as is
usual in iron ships.
When it is desirable to increase the effect of the machines electric
accumulators may be used and secondary batteries such as Planté's are
recommended.

page_text: tion or employment of magneto-electric or electro-magnetic machines for
the purpose of protecting or preserving ships' sheathing and armour
plating and other metal surfaces exposed to the action of sea water,
substantially as described.
In witness whereof, I, the said Michael Henry, have hereunto set
my hand and seal, this Sixth day of June, in the year One
thousand eight hundred and seventy-three.
Witness,
F. WALTERS,
68, Fleet Street.
M. HENRY. (L.S.)