IM- PROVEMENTS IN LIGHTING OR ILLUMINATING APPARATUS, CHIEFLY DESIGNED FOR USE IN MINES, TUNNELS, AND MANY-STORIED BUILDINGS.
Year: 1878

page_text: LETTERS PATENT to William Robert Lake, of the Firm of Haseltine, Lake, &
Co., Patent Agents, Southampton Buildings, London, for the Invention of " IM-
PROVEMENTS IN LIGHTING OR ILLUMINATING APPARATUS, CHIEFLY DESIGNED
FOR USE IN MINES, TUNNELS, AND MANY-STORIED BUILDINGS. A commu-
nication from abroad by Jacob W. de Castro, of the City and State of New
York, United States of America:
Sealed the 20th September 1878, and dated the 24th July 1878.
PROVISIONAL SPECIFICATION left by the said William Robert Lake at
the Office of the Commissioners of Patents on the 24th July 1878.
WILLIAM ROBERT LAKE, of the Firm of Haseltine, Lake, & Co., Patent Agents,
Southampton Buildings, London. "IMPROVEMENTS IN LIGHTING OR ILLUMINATING
APPARATUS, CHIEFLY DESIGNED FOR USE IN MINES, TUNNELS, AND MANY-STORIED
BUILDINGS." [A communication from abroad by Jacob W. de Castro, of the City
and State of New York, United States of America.]
The chief object of the said improvements, which relate to apparatus for dividing
and transmitting to several different points light from a single source, is to safely
illuminate the shafts and galleries of mines, underground tunnels, or the different
chambers of many-storied buildings; and the said Invention consists chiefly in
combining with a powerful source of light mirrors for condensing and parallelizing
the rays of light and directing them into the mouth of a tube, from the opposite
end of which they are reflected in one or more different directions by means of
mirrors or prisms into the mouth or mouths of smaller tubes, from which they may
be again reflected by inirrors or prisms in another direction or directions, until;
being finally carried to the required point, they are thrown against a mirror or
prism which reflects or refracts them into the chamber or space or upon the object
to be illuminated; the mirrors or lenses employed being either plane, concave,
convex, plano-concave, or plano-convex, as may be required, and the relative areas
of the primary receiving tube and the distributing tubes being proportioned with
[Price Gd 1

page_text: reference to the capacity of the condensing mirrors to intensify the beam of light
thrown into the primary receiving tube.
The said Invention also includes the establishment in connection with the
said tubes of reservoirs or magazines containing chloride of calcium, caustic lime,
or other substances which are powerful absorbents of moisture, for the purpose of
keeping the air in the tubes dry and clear.
In carrying the said Invention into practice I collect and condense rays of light
from an artificial source (preferably electric light), and as the chambers, spaces, or
objects illuminated by means of the said apparatus are so illuminated without the
presence in them or proximity of any incandescent body, this Invention affords
a means for lighting many-storied buildings or the galleries of mines without any
danger from fire.
Another advantage of this Invention when employed to distribute artificial light
results from the fact that the apparatus producing the light is at one point, for
example, at the mouth of a shaft or in the engine room of a large factory, where
it is under the control of a single operator, and where if the clectric light is used
it is produced with the shortest possible circuit.
The most economical way of producing a large quantity of electric light is by
the use of a single large machine in preference to the use of several smaller
machines. As a rule the larger the dynamo-electric machine employed the greater
is the per-centage of mechanical energy which is converted into light.
It will be seen that by means of this Invention all the light required for illu-
minating a multiplicity of chambers may be generated at one point with a single
large dynamo-electric machine and therefore with the greatest possible economy.
It will be understood that it may be desirable to have two dynamo-electric
machines, so that if one gets out of order the other may be ready for use.
This Invention may be employed in various ways and for various purposes, its
essential characteristic being the sub-division, reflection, and diffusion in various
directions and to different points of a suitably condensed beam of light, originally
thrown into a primary receiving tube or upon a prism.
The said apparatus will be somewhat modified in its construction according to
the uses to which it is to be applied.
When used for illuminating a mine I provide a vertical tube, which is placed in
the shaft of the mine and terminates at the top at or near the surface of the ground.
Immediately over the mouth of this tube there is a concave mirror for condensing
and throwing into the tube the rays of an electric light produced in the usual
manner between carbon electrodes, which are respectively connected with the
opposite poles of a dynamo-electric machine. At the bottom of the said vertical
tube an adjustable mirror, inclined at an angle of forty-five degrees, reflects the
beam of light thrown downward upon it into a horizontal tube. At the further
end of the said horizontal tube the beam of light is caught upon another adjustable
mirror set in a vertical plane upon the angle required to reflect the beain of light
into another tube, when a portion of the beam of light is intercepted by a third
mirror so inclined as to reflect the intercepted light downward into another
vertical tube extending downward to a lower level of the mine. The light thus
thrown down is caught upon a prism and refracted laterally in opposite directions
into two other tubes, or if it be desired a polyhedric prism may be employed and
the light may be refracted in a greater number of directions.
If it be desired to throw a portion of the light downward from one of the last-
named horizontal tubes a portion of the bottom of the tube is removed, and a mirror
is fastened in the upper part of the tube and inclined downward at any desired
angle. By making this mirror semi-cylindrical the light caught upon it may be
reflected divergently. The portion of the light not intercepted by the aforesaid
third mirror in the horizontal tube is caught by a fourth mirror, set in a vertical
plane at the proper angle to reflect the beam of light into another horizontal tube,
from the opposite end of which it is caught upon a fifth mirror and reflected into
another tube, from the mouth of which it is thrown upon a convex mirror by

page_text: which it is reflected divergently for the purpose of illuminating neighbouring
objects.
It will be understood that the directions in which beams of light are reflected,
and the relative positions of the tubes, will depend upon the directions and relative
positions of the galleries of the mine.
The reflecting mirrors are mounted upon axes at right angles to the direction of
the beam thrown upon them, for the purpose of facilitating their adjustment with
reference to the direction in which they are required to reflect the light.
If desired the reflecting mirrors may be made adjustable in all directions, but it
will ordinarily be sufficient to provide them with axes of oscillation at right angles
with the directions in which the beam of light strikes them. This may be con-
veniently effected by securing the frame of the mirror between two vertical pivots.
One or both of these pivots may have a screw thread cut upon it, and will thus
answer as a set screw to hold the mirror in the required position.
A simple mode of adjusting the mirrors is to insert them in place successively.
For the purpose of keeping the air in the tubes dry and clear, magazines
containing chloride of calcium, caustic lime, or some other powerful absorbent of
moisture are affixed to the under sides of the tubes. These inagazines are made
detachable, so that they may be withdrawn and recharged with absorbent material
when required.
In adapting the said Invention for a building containing, say, six stories, I
construct the apparatus with a vertical receiving tube, at the bottom of which is
the electric light apparatus and a parabolic mirror for collecting and throwing an
intense beam of light upward.
A dynamo-electric machine is placed in close proximity to the lower end of the
tube, so that the electric light may be produced upon the shortest possible circuit.
The beam of light thrown upward in the said receiving tube is intercepted by
mirrors, all of which are set on angles of forty-five degrees, and which respectively
reflect the portions of the beam of light which they intercept into the several
stories of the building through openings near the respective ceilings of each story.
The horizontal beam of light thus reflected may be thrown upon convex mirrors
and thus divergently reflected into the chamber required to be lighted, or they may
be thrown upon plane mirrors and reflected downward therefrom upon polyhedric
prisms, by which they may be refracted in various directions for the purpose of
lighting the chamber.
The polyhedric prisms may also be usefully employed for lighting streets radi-
ating from a common centre, in which case the number of facets of the polyhedron
will correspond with the number of streets required to be lighted. The beam of
light in this case may be thrown upon the base of polyhedric prism by means of a
parabolic mirror either with or without the interposition of any receiving tube
between the prism and the parabolic mirror.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said William Robert Lake in the Great Seal Patent Office on the 24th
January 1879.
WILLIAM ROBERT LAKE, of the Firm of Haseltine, Lake, & Co., Patent Agents,
Southampton Buildings, London. "IMPROVEMENTS IN LIGHTING OR ILLUMINATING
APPARATUS, CHIEFLY DESIGNED FOR USE IN MINES, TUNNELS, AND MANY-STORIED
BUILDINGS." A communication from abroad by Jacob W. de Castro, of the City
and State of New York, United States of America.
The principal object of my improvements, which relate to apparatus for dividing
and transmitting to several different points light from a single source, is to safely
illuminate the shafts and galleries of mines, underground tunnels, or the different
chambers of many-storied buildings; and my Invention comprises the combining
with a powerful source of light a peculiar arrangement of mirrors for condensing
and parallelizing the light rays and directing them into the mouth of a tube, from
the opposite end of which they are reflected in one or more different directions by
means of mirrors or prisms into the mouth or mouths of smaller tubes, from which
they may be again reflected by mirrors or prisms in another direction or directions,
until, being finally carried to the required point they are thrown against a mirror
or prism which reflects or refracts them into the chamber or space or upon the
object to be illuminated, the mirrors or lenses employed being either plane, concave,
convex, plano-concave, or plano-convex, as may be required, and the relative areas
of the primary receiving tube and the distributing tubes being proportioned with
reference to the capacity of the condensing mirrors to intensify the beam of light
thrown into the primary receiving tube.
My Invention also includes the establishment in connection with the tubes of
reservoirs or magazines containing chloride of calcium, caustic lime, or other sub-
stances which are powerful absorbents of moisture, for the purpose of keeping the
air in the tubes dry and clear.
In carrying my Invention into practice I collect and condense rays of light from
an artificial source, preferably electric light, and as the chambers, spaces, or objects
illuminated by means of my apparatus are so illuminated without the presence in
them or proximity of any incandescent body, my Invention affords the means for
lighting many-storied buildings or the galleries of mines without any danger from
fire.
Another advantage of my Invention when employed to distribute artificial light
results from the fact that the apparatus producing the light is at one point, for
example, at the mouth of a shaft or in the engine room of a large factory, where it
is under the control of a single operator, and where if the electric light is used it
is produced with the shortest possible circuit.
Finally. The most economical way of producing a large quantity of electric light
is by the use of a single large machine in preference to the use of several smaller
machines. As a rule the larger the dynamo-electric machine employed the greater
is the per-centage of mechanical energy which is converted into light.
It will be seen that by means of my Invention all the light required for illumi-
nating a multiplicity of chambers may be generated at one point with a single large
dynamo-electric machine and therefore with the greatest possible economy.
It will of course be understood that it may be desirable to have two dynamo-
electric machines, so that if one gets out of order the other may be ready for use.
My Invention may be employed in various ways and for various purposes, its
essential characteristics being the subdivision, reflection, and diffusion in various
directions and to different points of a suitably condensed beam of light originally
thrown into a primary receiving tube or upon a prism.
The accompanying Drawing represent several modifications of my apparatus,
illustrating the mode of applying my Invention to different purposes.

page_text: Figures 1, 2, and 3 are illustrations of apparatus for employment in lightingthe
galleries of mines.
Figure 4. illustrates the method of applying my Invention to the purpose of
lighting many-storied buildings.
Figure 1 is a top view of a system of tubes supposed to be traversing the galleries
of a mine or an assumed horizontal plane.
Figure 2 is an elevation showing the electric light apparatus and a condensing
mirror, the vertical tube in which the condensed beam of light is first received, a
portion of a horizontal tube receiving its light from the primary receiving tube and
a vertical tube depending downward from the horizontal tube receiving its light
therefrom, and distributing it by means of a prism in two or more opposite
directions in the galleries of the mine upon an assumed lower level.
Figure 3 is an assumed vertical section of the tubes shewn in Figure 1.
Figure 4 is a representation in vertical section of a portion of a many-storied
building, shewing a vertical primary receiving tube for the light, a dynamo-electric
machine near the base of such tube, and an electric light apparatus provided with
a parabolic mirror for condensing and throwing the light upward into the receiving
tube, also showing the lateral openings and mirrors for reflecting portions of the
light from the primary receiving tube into the various stories of the building, and
in several of the stories centrally placed prisms, upon which the beam of light from
the primary receiving tube is thrown and by which the beam is subdivided and
refracted in various directions.
Figure 5 is an illustration of my apparatus for lighting streets or avenues radi-
ating from a common centre.
Figure 6 is an isometrical perspective view of one of the reflecting mirrors,
showing the method in which it is adjustably mounted.
In the Drawing no attention is paid to proportions, smaller objects being shewn
disproportionately large for the sake of clearness of representation.
In the apparatus represented in Figures 1, 2, and 3, the vertical tube A is
supposed to be placed in the shaft of a mine, and to terminate at the top at or near
the surface of the ground. Immediately over the mouth of this tube there is a
concave mirror B for condensing and throwing into the tube the rays of an electric
light produced in the usual way between the carbon electrodes C, C, which are
respectively connected with the opposite poles of a dynamo-electric machine. At
the bottom of the tube A an adjustable mirror D, inclined at an angle of forty-five
degrees, reflects the beam of light thrown downward upon it into the horizontal tube a.
At the further end of the horizontal tube a the beam of light is caught upon the
adjustable mirror D', set in a vertical plane upon the angle required to reflect the
beam of light into the tube a¹, when a portion of the beam of light is intercepted by
the mirror D², so inclined as to reflect the intercepted light downward into the vertical
tube A', which is assumed to be a tube extending downward to a lower level of the
mine. The light thus thrown down is caught upon the prism E and refracted laterally
in opposite directions into the tubes e, e', or if it be desired a polyhedric prism may
be employed and the light may be refracted in a greater number of directions.
If it be desired to throw a portion of the light downward from the horizontal
tube e a portion of the bottom of the tube is removed, and a mirror E' is fastened
in the upper part of the tube and inclined downward at any desired angle. By
making this mirror semi-cylindrical the light caught upon it may be reflected
divergently. The portion of the light not intercepted by the mirror D² in the
horizontal tube a¹ is caught by the mirror D³, set in a vertical plane at the proper
angle to reflect the beam of light into the horizontal tube a², from the opposite end
of which it is caught upon the mirror D' and reflected into the tube as from the
mouth of which it is thrown upon the convex mirror F by which it is reflected
divergently for the purpose of illuminating neighbouring objects.
It will be understood that the directions in which beams of light are reflected,
and the relative positions of the tubes, will depend upon the directions and relative
positions of the galleries of the mine.

page_text: The reflecting mirrors are mounted upon axes at right angles to the direction of
the beam thrown upon them, for the purpose of facilitating their adjustment with
reference to the direction in which they are required to reflect the light.
If desired, the reflecting mirrors may be made adjustable in all directions, but
it will ordinarily be sufficient to provide them with axes of oscillation at right
angles with the directions in which the beam of light strikes them. This may be
conveniently effected by securing the frame L of the mirror between two vertical
pivots and, as shown in detail at Figure 6. One or both of these pivots may
have a screw thread cut upon it, and will thus answer as a set screw to hold the
mirror in the required position.
A simple mode of adjusting the mirrors is to insert them in place successively;
for example, when the mirror D¹ is not inserted a view may be obtained of the
mirror D through an aperture in the side of the tube a¹ immediately opposite the
tube a.
When the mirror D has been properly adjusted the mirror D' may be
inserted, and a similar view of that mirror may be obtained from the opposite end
of the tube a¹ through an aperture in the outers ide of the tube a², the mirror D³
may then be inserted, and so on.
For the purpose of keeping the air in the tubes dry and clear the magazines G,
containing chloride of calcium, caustic lime, or some other powerful absorbent of
moisture, are affixed to the under sides of the tubes. These magazines are made
detachable, so that they may be withdrawn and recharged with absorbent material
when required.
Figure 4 is an arbitrary representation in vertical section of a portion of a six-
storied building lighted according to my Invention. The apparatus in this case
consists of a vertical receiving tubo A2, at the bottom of which is the electric light
apparatus and a parabolic mirror B for collecting and throwing an intense beam of
light upward.
A dynamo-electric machine H is placed in close proximity to the lower end of
the tube, so that the electric light may be produced upon the shortest possible
circuit. The beam of light thrown upward in the receiving tube A³ is intercepted
by the mirrors B1, B2, B3, B4, B5, and B, all of which are set at angles of forty-five
degrees, and which respectively reflect the portions of the beam of light which they
intercept into the several stories of the building through the openings 61, 62, 63,
64, 65, 66, near the respective ceilings of each story. The horizontal beam of light
thus reflected may be thrown upon convex mirrors J, and thus divergently reflected
into the chamber required to be lighted, or they may be thrown upon plane
mirrors K and reflected downward therefrom upon polyhedric prisms k, by which
they may be refracted in various directions for the purpose of lighting the
chamber.
The polyhedric prisms may also be usefully employed for lighting streets radi-4
ating from a common centre, in which case the number of facets of the polyhedron
will correspond with the number of streets required to be lighted. The beam of
light in this case may be thrown upon the base of the polyhedric prism k by means
of a parabolic mirror B, either with or without the interposition of any receiving
tube between the prism and the parabolic mirror.
Having thus fully described the said Invention as communicated to me by my
foreign correspondent, and the manner of performing the same, I wish it understood
that I do not claim broadly throwing of light into a tube, but I claim in apparatus
for transmitting and dividing a beam of light for the purpose of illuminating several
different chambers, spaces, or objects,―
First. A dynamo-electric machine or other apparatus for generating a current of
electricity, and in circuit therewith an electric light apparatus arranged opposite
the mouth of the receiving tube, provided with a mirror for condensing the light
and throwing a beam of light of predetermined intensity into the receiving tube
and upon a mirror or prism arranged in the receiving tube, and adapted to intercept
and reflect or refract the beam of light into the other tube or tubes at any desired
angle or angles, and mirrors or prisms for receiving the intercepted portions of the

page_text: beam of light thrown into the receiving tube, and diffusing such light into the
spaces or upon the objects required to be illuminated, as above set forth and shewn
in Figures 1, 2, and 3 of the Drawings.
Second. In an apparatus composed of a system or series of tubes for receiving
and transmitting in the prescribed direction or directions light from an electric light
apparatus, adjustable mirrors, as and for the purpose set forth.
Third. In combination with a system or series of tubes for transmitting light,
as above described, magazines containing chloride of calcium, caustic lime, or
other powerful absorbent material for the purpose of keeping the air in the tubes
dry and clear.
In witness whereof, I, the said William Robert Lake, have hereunto set my
hand and seal, this Twenty-fourth day of January, in the year of our Lord
One thousand eight hundred and seventy-nine.
W. ROBT. LAKE. (L.S.)