AN IMPROVED MANUFACTURE OF METAL PLATES FOR SHEATHING THE BOTTOMS OF SHIPS OR OTHER VESSELS
Year: 1846

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, GEORGE
FREDERICK MUNTZ, Esquire, M.P., of Ley Hall, near Birmingham, send
greeting.
WHEREAS Her present most Excellent Majesty Queen Victoria, by Her
Royal Letters Patent under the Great Seal of the United Kingdom of Great.
Britain and Ireland, bearing date at Westminster, the Fifteenth day of
October, One thousand eight hundred and forty-six, in the tenth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me,
the said George Frederick Muntz, my exors, admors, and assigns, Her
especial licence, full power, sole privilege and authority, that I, the said
George Frederick Muntz, my exors, admors, and assigns, or such others as
the said George Frederick Muntz, my exors, admors, or assigns, should
at any time agree with, and no others, from time to time and at all times
during the term of years therein expressed, should and lawfully might make,
use, exercise, and vend, within England, Wales, and the Town of Berwick-
upon-Tweed, my Invention of " AN IMPROVED MANUFACTURE OF METAL PLATES
FOR SHEATHING THE BOTTOMS OF SHIPS OR OTHER VESSELS;" in which said Letters
Patent is contained a proviso that I, the said George Frederick Muntz,,
shall cause a particular description of the nature of my said Invention, and
in what manner the same is to be performed, by an instrument in writing
under my hand and seal, to be inrolled in Her said Majesty's High Court
of Chancery within six calender months next and immediately after the date
of the said in part recited Letters Patent, as in and by the same, reference.
being thereunto had, will more fully and at large appear.
- NOW KNOW YE, that in compliance with the said proviso, I, the said
George Frederick Muntz, do hereby declare that the nature of my said

page_text: Invention, and the manner in which the same is to be performed, are fully
described and ascertained in and by the following statement thereof, that is
to say:
My invention has for its object to improve the manufacture of my sheathing
metal, for which Letters Patent were granted to me on the Twenty-second
day of October, One thousand eight hundred and thirty-two, which consisted
of employing an alloy of copper and zinc in such relation to each other that
whilst the copper was to a considerable extent preserved there was a sufficient
oxydation to keep the bottom of a ship or vessel clean, and in practice it was
found by me to require as nearly as might be sixty parts ofcopperto forty parts
of zinc for that purpose, and such proportions of copper to the zinc could not
be reduced, even to a very small extent, without rendering the alloy liable
to have the zinc separately acted on, which was highly prejudicial. Now
the present Invention consists of so using another suitable metal or metals
when copper and zinc are combined for the purpose of sheathing, as to allow
the mixture to contain a less proportion of copper than about sixty of copper
and forty of zinc, and at the same time to obtain a sufficient degree of oxyda-
țion and prevent separate action on the zinc, and thereby to keep the bottom
of a ship or vessel clean.
In order that my Invention may be most fully understood and readily
carried into effect, I will proceed to describe an alloy of copper and zinc with
another metal, according to my present Invention, suitable for sheathing,
which I have found to possess the same properties of oxydation as my former
metal, and yet with an important reduction of the quantity of the copper
employed, and by which the cost of producing sheathing metal is materially
reduced. This alloy consists of fifty-six parts of copper, forty and three
quarter parts of zinc, and three and one quarter parts of lead. And in form-
ing such alloy I prefer to employ the purest metals I can obtain, as I believe
there is nothing gained by using inferior metals in making alloys. In pro-
'ducing the desired compound I employ an additional quantity of the zinc to
allow for loss, as is well understood, so as to obtain as nearly as may be an
alloy consisting of the quantities of the metals above mentioned. I would
remark, that the lead in the above compound or alloy acts a very important
part, as an alloy consisting of fifty-sixparts ofcopper and fortyand three quarter
parts of zinc would not without the lead produce a metal which would oxydise
sufficiently to keep the bottom of a ship or vessel clean. The alloy being
made and cast into ingots it is to be rolled into sheets, and by preference at
a red heat, and the sheets produced are to be annealed; and if it is desired
that they should be cleaned they are to be cleaned by a mixture of sulphuric
and nitric acids properly diluted, as is well understood. I would also remark,

page_text: that although I have been exact in stating the proportions of the metal one
to the other which I prefer, 1 do not confine myself thereto, as the quantity
of the copper may be increased, adding however thereby to the cost of the
sheathing metal; and the quantity of copper may be decreased to a slight
extent, but certainly not so low as to bring it to fifty per cent. of the alloy
obtained, and yet produce rolled sheets suitable for sheathing metal, and which
will oxydate to such an extent as to keep the bottom of a ship or vessel clean.
And although I have described the use of lead only as an addition to copper
and zinc with a view to save copper, yet I do not confine myself thereto, as
other suitable metals may be used, though so far as I have ascertained not
with equal advantage to lead.
Having thus described the nature of my Invention, and the manner in
which the same is to be performed, I would state that I am aware that lead
and other metals have before been proposed to be combined with copper and
zinc for sheathing and other purposes, but not within the proportions herein
mentioned, so as to keep the bottom of the vesel clean by a sufficient oxydation
of the copper; I do not therefore claim the combination of lead or other metals
with copper and zinc for sheathing, but only when manufactured according to
this my Invention. And I would have it understood that what I claim is, the
manufacture of sheathing metal herein described, by so using other suitable
metal or metals when copper and zinc are combined for the purpose of sheath-
ing, as to allow the mixture to contain a less proportion of copper than about
sixty of copper and forty of zinc, and at the same time obtain a sufficient
degree of oxydation and prevent separate action on the zinc.
In witness whereof, I, the said George Frederick Muntz, have hereunto
set my hand and seal, this Fifteenth day of April, in the year of our
Lord One thousand eight hundred and forty-seven.
GEORGE FREDERICK (L.S.) MUNTZ.
AND BE IT REMEMBERED, that on the Fifteenth day of April, in the
year of our Lord 1847, the aforesaid George Frederick Muntz came before
our said Lady the Queen in Her Chancery, and acknowledged the Specifi-
cation aforesaid, and all and everything therein contained and specified, in
form above written. And also the Specification aforesaid was stamped
according to the tenor of the Statute made for that purpose.