IMPROVEMENTS IN CONSTRUCTING REFLECTORS
Year: 1858

page_text: LETTERS PATENT to Charles Fréderic Vasserot, of 45, Essex Street,
Strand, London, Patent Agent, for the Invention of "IMPROVEMENTS IN
CONSTRUCTING REFLECTORS."-A communication from Antoine Marie
Balencie, residing in Paris, in the Empire of France.
Sealed the 8th April 1859, and dated the 11th October 1858.
PROVISIONAL SPECIFICATION left by the said Charles Fréderic Vasserot
at the Office of the Commissioners of Patents, with his Petition, on
the 11th October 1858.
I, CHARLES FREDERIC VASSEROT, of 45, Essex Street, Strand, London,
Patent Agent, do hereby declare the nature of the said Invention for
"IMPROVEMENTS IN CONSTRUCTING REFLECTORS," (a communication from Antoine
Marie Balencie, residing in Paris, in the Empire of France,) to be as follows,
and consists in dissolving chloride of platinum or of palladium in pure
essence of lavender, when evaporated to a proper thickness, in a water bath,
of a metallic flux (formule de porcelaine de Saxe) is added, and the whole
is then spread upon the glass which is to form the reflector. The reflector is

page_text: then placed in an oven and is baked at a heat of 1,800 degrees for 32 seconds.
When cool, the back of the reflector may be painted and protected by means
of a plate of metal or otherwise.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Charles Fréderic Vasserot in the Great Seal Patent Office
on the 11th April 1859.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, CHARLES
FREDERIC VASSEROT, of 45, Essex Street, Strand, London, Patent Agent,
send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Eleventh day of October, in the year of our Lord
One thousand eight hundred and fifty-eight, in the twenty-second year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me, the
said Charles Frederic Vasserot, Her special licence that I, the said Charles
Fréderic Vasserot, my executors, administrators, and assigns, or such others
as I, the said Charles Fréderic Vasserot, 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 CONSTRUCTING REFLECTORS," a communication from Antoine
Marie Balencie, residing in Paris, in the Empire of France, upon the condition
(amongst others) that I, the said Charles Fréderic Vasserot, 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 Fréderic Vasserot, 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 :-
This Invention has for its object improvements in constructing reflectors.
For this purpose I coat the surface of the glass on which it is desired to

page_text: produce a reflecting surface with a salt of platinum or palladium mixed with
a suitable vehicle and also with a flux, and I expose the glass so coated to a
heat sufficient to reduce the metal, and at. the same time to cause the flux to
run over and combine with the surface of the glass.
And in order that the said Invention may be most fully understood and
readily carried into effect, I will proceed to describe the manner in which I
prefer to conduct the process. I make a saturated solution of boracic acid in
essence of lavender, and I mix one part of this solution with from 10 to 15
parts of dry bichloride of platinum or bichloride of palladium, using more or
less bichloride according to the thickness of the metallic coating, which it is
desired to produce on the surface of the glass. This mixture I apply to the
glass with a camel-hair brush, taking care that the brush is brought in contact
with every part of the surface on which a deposit of metal is required. I
then pour over the surface a small quantity of the mixture, and cause it
to run all over the glass; afterwards I cause the surplus liquid to run off
by inclining the plate.
The glass thus prepared is laid on a suitable surface and placed in a muffle
contained within a furnace; the muffle is heated to a full red heat, and the
glass is kept in the furnace until its surface becomes softened. The heat first
causes the prepared surface to become black, and afterwards to assume a
metallic and brilliant appearance. When this change has taken place the
process is complete, and the glass is removed from the furnace and ammealed
and cooled in the usual manner.
In applying the heat, care must be taken not to inflame the essence of
lavender. If the metallic coating obtained by the first operation is not
sufficiently thick, or if the surface of the glass is not uniformly coated, the
entire process may be repeated. If the first coating is satisfactory, I finish
the plate by giving it a coating of a saturated solution of boracic acid in
essence of lavender or in alcohol, and again expose the plate to heat as before;
the heat, however, being continued for a longer period, and being raised as high
as the plate will bear without injury to its surface; this finishing process
renders the adhesion between the metallic deposit and the surface of the glass
more complete. In some cases, when it is desired to produce a concave
reflector or a curved reflecting surface, I bend the sheet of glass to the desired
form and produce the metallic deposit upon it at one heat; and for this purpose
I support the sheet of glass in the muffle on a suitable form, into which the
glass sinks when it becomes soft, or the plate of glass may be first bent in
the usual manner before applying the process. In place of essence of lavender

page_text: other vehicles may be employed; for example, in some cases colodion may
conveniently be substituted for essence of lavender, and in place of boracic
acid other fluxes may be employed, but not I believe with the same advantage
as boracic acid.
In witness whereof, I, the said Charles Fréderic Vasserot, have hereunto
set my hand and seal, this Eleventh day of April, in the year of our
Lord One thousand eight hundred and fifty-nine.
CH. FREDO VASSEROT. (L.S.)