AN IMPROVED TRANSLUCENT MEDIUM FOR REFLECTING, REFRACTING, AND DIFFUSING LIGHT, CAPABLE OF APPLICATION TO VARIOUS OTHER PURPOSES
Year: 1878

page_text: LETTERS PATENT to Isac Louis Pulvermacher, of 194, Regent Street, in the
County of Middlesex, Electrician, for the Invention of "AN IMPROVED
TRANSLUCENT MEDIUM FOR REFLECTING, REFRACTING, AND DIFFUSING LIGHT,
CAPABLE OF APPLICATION TO VARIOUS OTHER PURPOSES."
d the 10th January 1879, and dated the 14th October 1878
PROVISIONAL SPECIFICATION left by the said Isac Louis Pulvermacher at
the Office of the Commissioners of Patents on the 14th October 1878.
ISAC LOUIS PULVERMACHER, of 194, Regent Street, in the County of Middlesex,
Electrician. "AN IMPROVED TRANSLUCENT MEDIUM FOR REFLECTING, REFRACTING,
AND DIFFUSING LIGHT, CAPABLE OF APPLICATION TO VARIOUS OTHER PURPOSES."
The object of this Invention is a translucent medium for softening the brilliancy
of a too intense light without waste of the light power by absorption, and for various
other purposes.
It is well known that ground glass globes or opalized glass soften
an intense light to the detriment of light power, some of which is destroyed by
absorption. My new method of softening the light consists in using semi-spherical
or conical glass globes beneath and surrounding the luminous centre, the inner
surface of such glasses being internally platinized by a chemical process creating a
brilliant platine surface, which at the same timo possesses a sufficient degree of
translucency for allowing the light to penetrate in the suitable subdued degree.
The reflecting surface inside the globe or cone may be utilized to light up another
reflector adapted above it at a suitable angle and distance which may be of a sur-
face diffusing light uniformly.
The glass globe or cone as also the reflector above may be plain, or provided on
one side with semi-spherical bead-like projections formed during manufacture by
the moulding process used for cheap ornamentation of glass sugar basins and the
like.
The semi-transparent platinization of glass is capable of application to many
other purposes, for instance, in cab windows and as transparent mirrors in
partitions.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Isac Louis Pulverinacher in the Great Seal Patent Office on the
12th April 1879.
ISAC LOUIS PULVERMACHER, of 194, Regent Street, in the County of Middlesex,
Electrician. "AN IMPROVED TRANSLUCENT MEDIUM FOR REFLECTING, REFRACTING,
AND DIFFUSING LIGHT, CAPABLE OF APPLICATION TO VARIOUS OTHER PURPOSES."
Various means are employed in general lighting operations to soften or tone down
a light too intense for the eyes. These means principally consist in the use of
glasses or globes of ground glass or of opal glass, but it is certain that this softening
or toning down which absorbs a large part of the light is obtained to the detriment
of the lighting power of the various apparatus, which thereby lose a considerable
part of their effectiveness.
Now the object of my Invention is to soften the brilliancy of a too intense light
without sacrificing the lighting power of the luminous source.
These results I obtain by employing apparatus of glass or other suitable material
surrounding the light, furnished with a layer or coating of inctal chemically
deposited on the interior in an even state which allows it a suitable degree of
transparency, and at the same time presenting a brilliant surface, from which it
results that the light which is partly prevented from passing through the glass is
reflected towards the upper part, and from there again reflected by a diffusing
reflector of suitable shape and surface.
My apparatus are formed of glass, crystal, mica, or other suitable material, and
may be white or plain, opalised, or stained in different colours, and they may also
take any shape such as spherical, semi-spherical, parabolic, hyperbolic, cylindrical,
conical, prismatic, or any other suitable shape. They may be applied either to
electric lighting apparatus, to lighting by gas, or other means. The shape and size
may vary according to the mode of lighting to which they are adapted.
The interior surface of the apparatus may be plain and polished or "corrugated" in
various directions. The exterior surface may also be polished, plain, or with
traversing lines, or they may be provided with raised spots in the form of half
pearls, round spots, or other shape, placed in lozenge-shaped order and touching
each other; these raised spots are formed in the moulding.
The interior surface (and this is the chief point of my Invention) is by preference
platinized with a coat or layer more or less dense, so as to render this surface
imetallic and brilliant, at the same time retaining a certain degree of transparency.
This platinization is obtained by the known chemical processes for platinizing
glass. When I employ metal shades polished and platinized on their internal
surface, I perforate them with a multidude of very fine holes in order to render
them translucent.
I have shown on the annexed Drawing, Figure 1, a support of any lighting
apparatus as an example.
This support a is provided with a shading apparatus b of glass, crystal, mica, or
other suitable material which surrounds the light supposed to be at D. The inside
surface of the shading apparatus b is platinized, brilliant, and solidified, or "fixed"
by burning; it reflects upward like a mirror that portion of light which cannot pass
through the shading apparatus, thus softening the light in consequence of its becoming
toned down, resulting from the non-transparent platinum particles. This toning
down, which may be more or less intense, nevertheless permits transparency, so that
the light even though it be an electric light is not too bright or dazzling for the
eyes.
The light reflected by the shading apparatus b may then be diffused either in the
direction of the re-reflecting apparatus c, or freely over a white ceiling or other
white surface if the re-reflecting cover is not employed.
Thus it is seen that all the lighting power is utilized, and that portion of the

page_text: light which passes through the shade b by transparency may be rendered very
soft. The refraction and diffusion of the light may be considerably increased by
the raised spots or half pearls which may cover the exterior or outer surface of the
shading apparatus b.
The re-reflecting apparatus c placed above the shade b is made of metallised
glass or other material and is intended to receive the direct rays of light, also
those reflected towards it to again reflect them in a diffused state in the desired
direction.
The shape of this reflector should be adapted to the direction in which the
reflected light is required to be utilized; it may be flat, concave, convex, or pointed,
as shown in Figure 2, with plain or with corrugated surface so as to effect the
diffusion of the reflected light. This reflector c may be made in one piece with the
reflector shading apparatus b, as shown in Figure 3; in this case a portion of the
surface of the glass between the upper platinized part c, and the platinized shading
apparatus b is left unplatinized and completely transparent.
The surfaces of my apparatus which face the light may be platinized entirely, or
in certain parts only. As for example in the case of spherical globes, the half of
which may be transparently platinized and the other half completely transparent,
I may employ materials other than glass, crystal, or mica for establishing my
apparatus by rendering them reflecting in the interior, and at the same time
transparent.
And having now described the nature of my said Invention and in what manner
the same is to be performed, I declare that I claim as my Invention the apparatus
above-described, which may be made in any shape and of any dimensions appli-
cable to general lighting, of which the shading apparatus is principally obtained by
a deposit of very fine metal, incrustated and solidified on the interior surface of the
glass, crystal, mica, metal, or other suitable material. These apparatus are coated
preferably by platinum in such a way as to be rendered reflecting and transparent
simultaneously, in the object of utilizing all the lighting power of the luminous
source by the diffused reflection of the direct rays, and of those already reflected
by the shade reflector.
In witness whereof, I, the said Isac Louis Pulvermacher, have hereunto set
my hand and seal, this Tenth day of April, One thousand eight hundred
and seventy-nine.
I. L. PULVERMACHER. (L.S.)