IMPROVEMENTS IN PREPARING AND FIXING STREET AND OTHER INSCRIPTIONS OR LETTERING ON METALLIC PLATES."
Year: 1861

page_text: LETTERS PATENT to Adolphe David, junior, of Nantua, in the Empire of
France, for the Invention of "IMPROVEMENTS IN PREPARING AND FIXING
STREET AND OTHER INSCRIPTIONS OR LETTERING ON METALLIC PLATES."
PROVISIONAL SPECIFICATION left by the said Adolphe David at the
Office of the Commissioners of Patents, with his Petition, on the 4th
October 1861.
I, ADOLPHE DAVID, junior, of Nantua, in the Empire of France, do hereby
declare the nature of the said Invention for "IMPROVEMENTS
IN PREPARING
AND FIXING STREET AND OTHER INSCRIPTIONS OR LETTERING ON METALLIC. PLATES,"
to be as follows:-
I propose using plates of zinc, iron, copper, or other metal with letters,
vignettes, ciphers, or any inscription in relief, such lettering or inscription
being cast with the plate, or moveable and screwed, or rivetted upon it, or
chased or stamped out; the plates are then scoured, using any suitable acid to
remove all trace of oxide. After sufficient washing and dessication, each plate
is coated with wax, and placed in an oven. The wax spreads, penetrates into
the pores (especially of cast iron) and interstices, coats them, and prevents any
introduction of water, and consequent oxidation. Any superabundance of wax
being removed, two coats of paint mixed with drying oils are put over the
entire surface of the plate, lettering, or vignette inclusive.
Price 1
This paint being

page_text: dry, any shade of rather thick color is taken up with a tamkin or rubber, and
laid on the lettering or relief in two thin coats, and a slight coating of copal
or caoutchouc varnish will give more lustre to the plate. This process
of laying on color with the tamkin may be renewed when required without
removing the plate, and the moveable letters be cut out with a chisel, or un-
screwed, and new ones screwed in their place if it be desired to change any
part of the inscription.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Adolphe David in the Great Seal Patent Office on the 29th
March 1862.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, ADOLPHE
DAVID, junior, of Nantua, in the Empire of France, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria. by Her Letters
Patent, bearing date the Fourth day of October, in the year of our Lord One
thousand eight hundred and sixty-one, in the twenty-sixth year of Her reign,
did, for Herself, Her heirs and successors, give and grant unto me, the said
Adolphe David junior, Her special licence that I, the said Adolphe David,
junior, my executors, administrators. and assigns, or such others as I, the
said Adolphe David, junior, 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 "IMPROVE.
MENTS IN PREPARING AND FIXING STREET AND OTHER INSCRIPTIONS OR LETTERING
ON METALLIC PLATES," upon the condition (amongst others) that I, the said
Adolphe David, junior, my executors or administrators, by an instrument in
writing under my or their, or one of their hands and seals, should par-
ticularly 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 Adolphe David, junior, 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:-
Every system of sign or indicating plate hitherto adopted whether for sireçis,

page_text: roads, mile posts, letter posts, or other purposes, necessitates considerable
expenditure to keep the inscriptions upon the plates in a proper and serviceable
state, it being also necessary to remove the said plates to a workshop when
needing renovation, and thus deprive the public for an indefinite period of
these useful and often indispensable indications. My improved system has for
object to reduce the cost of repainting to an insignificant amount, (effecting
it without removing the plate), and to give to such plates, but principally to
those of cast iron, a durability quadruple that of plates painted in the usual
manner. My system is applicable to cast iron, zinc, copper, or even wrought iron
plates of any suitable size or thickness. The letters, ciphers, vignettes, or other
inscriptions (always in projection), are cast with the plate itself, or moveable,
and fixed with screws rivited or driven upon the plates or sheets. The shape
and size of the letters must, like that of the plates, depend upon the use to
which they are destined. The plates bearing these letters, ciphers, or other
inscriptions are, after the fusion of the metal, scoured with an acid to remove
from the surfaces all trace of oxyde. Each plate is then washed, and when suffi-
ciently dried is coated with wax, and placed in a heated oven. The wax runs
and spreads, penetrates into all the pores (especially of cast iron) and interstices,
stops them, and prevents any lodgment of water, and consequent oxydation.
This steeping in wax being effected, and all the superabundant wax removed,
the painting, properly so called, in drying oils is laid in two coats over the entire
surface, not excepting the letters or other projections. This painting may be
allowed to dry, and when dry, seize with a tamkin or rubber any desired shade
of somewhat thick color, and place the said color by dabbing or pressing the
tamkin upon the projections. Two thin layers of color will suffice to make
the projections stand clearly out. The first coats of paint may, if desired, be
at once wiped off the projections, and the color at once laid on them with the
tamkin. A coating of copal or caoutchouc varnish spread finally over the plate
will give more brilliancy to the whole. The projection of the letters or inscriptions
renders coloring with the tamkin or rubber easy, and permits the entire plate
to be readily painted, and the original inscription quickly restored to its primi-
tive distinctness and brilliancy, and at a cost fourteen times less than by the
most simple process now in use. The facility of putting on color with the
tamkin thus constitutes the principal, but not the only merit of my Invention.
This system of plates with projecting or raised letters or inscriptions permits
the removal of these letters, even when adhering to the surface of the plate,
(a few strokes of the chisel and file sufficing), and the substitution of fresh
letters cast separately, thus modifying or altering the inscription, such letters
having a couple of holes left in them corresponding with similar ones in the

page_text: plate to which they are fixed, and riveted with screws. These substituted or
additional letters may be colored by the tamkin as the others, and the inscrip-
tion is thus altered at small cost. To sum up my improved plates are of wrought
or cast iron, zinc, copper, or other metal with letters, ciphers, or other inscrip-
tions of the same metal in relief, they are painted in oils after being scoured
with acid and coated with wax, infiltrated into the pores by exposure to heat;
the said painting in drying oils and the wax covering all the surfaces, but the
letters in relief receiving two thin coats of different color to the body of the
plate, laid on with the tamkin or rubber; this laying on color with the
tamkin taking place whenever the inscription becomes tarnished, and from any
cause of deterioration requires fresh painting. My system of introducing wax
by heat into the ports of cast-iron plates is equally applicable to every other
oxydizable metal, such as wrought iron, steel, copper, zinc, or other, and may
therefore be used with advantage to prevent the oxydation of ship's armour
plates, railway sleepers, and rails, and other objects. Heat the piece of iron
or other metal to about 134% "Fahrenheit," then introduce with a brush into
the hollow parts, or those in relief, wax previously melted at a gentle heat.
The heat causes the pores of the metal to open, and the wax introducing itself
into the minutest parts, preserves them from oxydation. By this very cheap
and easy process, requiring no plant or special apparatus, the durability of
metals may be quadrupled, and even quintupled. and the most violent acids
might be spread over the surfaces without injuring them.
In witness whereof, I, the said Adolphe David, junior, have hereunto set
my hand and seal, this Twenty-fourth day of March, in the year of
our Lord One thousand eight hundred and sixty-two.
ADOLPHE DAVID, FILS. (L.S.)