AN IMPROVED COMPOUND OR MATERIAL FOR COATING OR COVERING METALLIC AND VEGETABLE SUBSTANCES TO PRESERVE THEM FROM CORROSION OR DECAY
Year: 1862

page_text: LETTERS PATENT to Charles Stewart Duncan, of Inverness Road, Bays-
water, in the County of Middlesex, for the Invention of "AN IMPROVED
COMPOUND OR MATERIAL FOR COATING OR COVERING METALLIC AND VEGETABLE
SUBSTANCES TO PRESERVE THEM FROM CORROSION OR DECAY."
Sealed the 30th January 1863, and dated the 28th October 1862.
PROVISIONAL SPECIFICATION left by the said Charles Stewart Duncan
at the Office of the Commissioners of Patents, with his Petition,
on the 28th October 1862.
I, CHARLES STEWART DUNCAN, of Inverness Road, Bayswater, in the
County of Middlesex, do hereby declare the nature of the said Invention
for AN IMPROVED COMPOUND" OR MATERIAL FOR COATING OR COVERING METALLIC
AND VEGETABLE SUBSTANCES TO PRESERVE THEM FROM CORROSION OR DECAY," to
be as follows-
This Invention consists of an improved compound or composition for
coating metals, woodwork, or vegetable bodies of various natures, in
order to preserve them from the decaying action or influence of the
atmosphere, or of water, acids, saline, or earthy matters, or generally
from any influence which would otherwise cause corrosion, oxydation,
or decay.
The compound is applicable for protecting and covering sheathing of
all characters, girders, bridges, balconies, or ironwork of all kinds when
exposed to destructive influences, as above, and it should be applied to

page_text: the surface of the iron or other metal previous to the application of
paint or varnish.
The compound is also applicable to the coating or preserving of
metallic work of other kinds, such as to steel, zinc, lead, tin, and copper,
or the various alloys of metals, to wire and ironwork of every description;
and with respect to vegetable bodies it is well adapted to coating and
preserving wood and woodwork, such as piers exposed to sea water, or
to wharves, and also to palings, railway sleepers, telegraph posts previous
to their being coated with paint, varnish, pitch, or tar.
The material or compound is to be made as follows:-I propose to use
marine glue, gutta percha, india-rubber, shellac, copal, mastic, or pitch
in combination with one or more of the following substances, alumina,
schist, quartz, slate, silex, or flint, marble or pozzalano, sand, sand-
stone, cement (natural or artificial), chalk, glass, emery, tripoli, white
oxide of zinc or of lead, in every case reduced to a fine and nearly impalp-
able powder in proportions varying from one-fourth part to five parts
of these powdered materials to one part or more of the before mentioned
plastic substances. The materials are then to be heated so as to reduce
them to a plastic or semi-liquid state; and I also heat the metal or metals
to be coated with the compound to a moderate temperature, and while
in this heated state I lay on the coating with brushes or by any con-
venient method. Immediately after the coating has been laid on the
metal, wood, or other body to be preserved, and before it is allowed to
cool, the compound is to be covered with a layer of one or more of the
mineral powders, before mentioned, in a warm state, in order to entirely
remove all stickiness or tack. When the compound has become cool the
surface may be brought to a smooth or polished exterior by rubbing it
with any ordinary substance used for rubbing down or polishing mineral
or metallic surfaces. In cases where necessary, I propose to give the
metals or woods a further protective coating or varnish composed of
copal, cupreous, or other varnish or naptha, paraffin, camphine,
petroleum, or other mineral or vegetable oils mixed with one or more
of the above-named pulverized substances. The coatings may be
repeated, if it is desired, to obtain extra thickness and protection. These
mineral substances must in all cases be thoroughly washed and freed
from impurities, and then be kiln-dried to desiccate and destroy vegeta
tion. The protective compound may be applied to the preservation of
ropes or strands of hemp or to any fibrous or textile materials or fabrics

page_text: SPECIFICATION in pursuance of the conditions of the Letters Pateut, filed
by the said Charles Stewart Duncan in the Great Seal Patent Office
on the 23rd April 1863.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, CHARLES
STEWART DUNCAN, of Inverness Road, Bayswater, in the County of
Middlesex, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-eighth day of October in the year of
our Lord One thousand eight hundred and sixty-two, in the twenty-sixth
year of Her reign, did, for Herself, Her heirs and successors, give and
grant unto me, the said Charles Stewart Duncan, Her special licence
that I, the said Charles Stewart Duncan, my executors, administrators,
and assigns, or such others as I, the said Charles Stewart Duncan, 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 COMPOUND
OR MATERIAL FOR COATING OR COVERING METALLIC AND VEGETABLE SUB-
STANCES TO PRESERVE THEM FROM CORROSION AND DECAY," upon the con-
dition (amongst others) that I, the said Charles Stewart Duncan, 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 Charles Stewart Duncan, 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:―
This Invention consists of an improved compound or composition for
coating metals, woodwork, or vegetable or animal bodies or substances
of various natures, in order to preserve them from the decaying action
or influence of the atmosphere, or of water, acids, saline or earthy
matters, or generally from any influence which would otherwise cause
corrosion, oxydation, or decay.
The compound is applicable for protecting and covering sheathing of

page_text: all characters, girders, bridges, balconies, or ironwork of all kinds when
exposed to destructive influences as above, and it should be applied to
the surface of the iron or other metal previous to the application of
paint or varnish.
The compound is also applicable to the coating or preserving of
metallic work of other kinds, such as to iron, steel, zinc, lead, tin, and
copper, or the various alloys of metals; to wire and wirework of every
description; and with respect to vegetable bodies, it is well adapted to
coating and preserving wood and woodwork, such as piers exposed to sea
water, or to wharves, and also to palings, railway sleepers, and telegraph
posts, previous to their being coated with paint, varnish, pitch, or tar.
The material or compound is to be made as follows:-I propose to use
marine glue, gutta percha, india-rubber, shellac, copal, mastic, vegetable
or mineral pitch or tar, or resin, or iodine, or sulphur, or creosote, or
asphalte bitumen, and coal tar in combination with one or more of the
following substances:-Alumina, schist, quartz, slate, silex, or flint,
marble, or pozzolano, sand, sandstone, cement (natural or artificial),
chalk, glass, emery, tripoli, white oxide of zinc or of lead, or the litharge
or red oxide of lead, in every case reduced to a fine and nearly impalpable
powder, in proportions varying from one-fourth part to five parts of these
powdered materials to one part or more of the before-mentioned plastic
substances. The materials are then to be heated, so as to reduce them
to a plastic or semi-liquid state; and I also heat the metal or metals to
be coated with the compound to a moderate temperature, and while in
this heated state I lay on the coating with brushes or by any convenient
method. Immediately after the coating has been laid on the metal,
wood, or other body to be preserved, and before it is allowed to cool, the
compound is to be covered with a layer of one or more of these mineral
powders before mentioned in a warm state, in order to entirely remove
all stickiness or tack. When the compound has become cool, the surface
may be brought to a smooth or polished exterior by rubbing it with any
ordinary substance used for rubbing down or polishing mineral or
metallic surfaces. In cases where necessary, I propose to give the
metals or woods a further protective coating or varnish composed of
copal, cupreous, or other varnish, or naptha, paraffine, camphine,
petroleum, or other mineral or vegetable oils, or silicate of potash or of
soda and sulphuric acid mixed with one or more of the above-named
pulverized substances. The coatings may be repeated if it is desired to
obtain extra thickness and protection.

page_text: These mineral earthy substances must in all cases be thoroughly
washed and freed from impurities, and then be kiln dried to desiccate.
and destroy vegetation. For a very hard coating the substance should
be composed of seven or eight parts of silica, or pozzalano, or chalk
instead of silica, to four parts of mineral pitch or tar and two parts of
vegetable or Stockholm tar. The protective compound may be applied
to the preservation of ropes or strands of hemp or to any fibrous or textile
materials or fabrics.
Having now described the nature of my said Invention, and the
manner in which the same is to be performed, I would remark in conclu-
sion that I do not limit myself to any specific proportions of the various
ingredients herein mentioned, as it is obvious that the same may be
regulated according to the purpose for which the compound may be
required; but what I claim and desire to be secured to me by the herein
in part recited Letters Patent, is, the manufacture of the improved
compound or material, substantially in the manner herein described for
the purposes set forth.
In witness whereof, I, the said Charles Stewart Duncan, have here-
unto set my hand and seal, this Tenth day of March, in the year
of our Lord One thousand eight hundred and sixty-three.
C. S. DUNCAN. (L.S.)
Witness,
L. J. WETHERELL,
Clerk to Messrs. Prince, Hammond, & Prince,
Office for Patents,
4, Trafalgar Square,
Charing Cross.