IMPROVEMENTS IN THE CONSTRUCTION OF ILLUMINATING GRATINGS FOR Roors, AREAS, FOOTWAYS, AND OTHER PLACES, AND IN GLASSES OR LIGHTS FOR ILLUMINATING PURPOSES
Year: 1871

page_text: LETTERS PATENT to John Henry Johnson, of 47, Lincoln's Inn Fields,
in the County of Middlesex, Gentleman, for the Invention of
"IMPROVEMENTS IN THE CONSTRUCTION OF ILLUMINATING GRATINGS FOR
Roors, AREAS, FOOTWAYS, AND OTHER PLACES, AND IN GLASSES OR LIGHTS
FOR ILLUMINATING PURPOSES."-A communication from abroad by
Theodore Hyatt, of New York, in the United States of America.
PROVISIONAL SPECIFICATION left by the said John Henry Johnson
at the Office of the Commissioners of Patents, with his Petition, on
the 18th February 1871.
I, JOHN HENRY JOHNSON, of 47, Lincoln's Inn Fields, in the County
of Middlesex, Gentleman, do hereby declare the nature of the said Inven-
tion for "IMPROVEMENTS IN THE CONSTRUCTION OF ILLUMINATING GRATINGS FOR
ROOFS, AREAS, FOOTWAYS, AND OTHER PLACES, AND IN GLASSES OR LIGHTS FOR
ILLUMINATING PURPOSES," a communication from abroad by Theodore Hyatt,
of New York, in the United States of America, to be as follows:-
This Invention has for its object the construction of frames or
gratings intended to receive glasses for the purpose of forming illumi-
nating roofs, coverings for areas, and walking surfaces for side walks
where light is required to be transmitted therethrough, and consists in

page_text: casting in such frames or gratings grooves or channels, or in perforating
or partially perforating the same in rows, or in combining perforations
or partial perforations with grooves or channels in order to facilitate
the subdivision of the said gratings into separate smaller portions or
sections of any given dimensions according to the requirements of
the particular roof or structure to be erected. These gratings are by
preference cast in long narrow lengths with the dividing grooves or
channels running transversely, such long lengths being supported along
each side by resting upon beams or bearers. The strength of the grating
is preserved by having a sufficient quantity of metal parallel to and on
cach side of the breaking line, which is transverse to the supporting
beams or bearers. Each opening in the frame is glazed with glass, the
whole forming a species of compound glass and iron or other metal tile
which can be kept in stock for use as required by reason of the facility
afforded for breaking or subdividing the same into parts of any given
length or width. For arched or curved roofs the said gratings may
have copper or other malleable metal wires cast along cach side so as to
admit of the different sections being bent at their dividing lines to suit
the curve and still hold such sections together, the joints along the
breaking lines being made good with cement or otherwisc.
I propose to make the lights or glasses for this and other descriptions
of illuminating gratings intended for foot pavements in such a way as
that the glass itself shall in a manner act as the medium for protecting
its surface from being scratched by the feet of the passengers. For
this purpose I mould or cast a convex lens upon a square or other
shaped flat glass plate, the diameter of the lens being nearly equal to
that of the base on which it is formed. At each corner of the base or
round the edge of the lens I form glass projections or buttons of a
height suflicient to prevent the contact of the fect with the sloping sides
of the lens thus protecting the same.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by tho said John Henry Johnson in the Great Seal Patent
Office on the 18th August 1871.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
HENRY JOHNSON, of 47, Lincoln's Inn Fields, in the County of Mid- 3
dlesex, Gentleman, send greeting.

page_text: WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Eighteenth day of February, in the year
of our Lord One thousand eight hundred and seventy-one, in the thirty-
fourth year of Her reign, did, for Herself, Her heirs and successors, give
and grant unto me, the said John Henry Johnson, Her special license
that I, the said John Henry Johnson, my executors, administrators,
and assigns, or such others as I, the said John Henry Johnson, my
exccutors, administrators, or 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
Ircland, the Channel Islands, and Isle of Man, an Invention for "Im-.
PROVEMENTS IN THE CONSTRUCTION OF ILLUMINATING GRATINGS FOR ROOFS, AREAS,
FOOTWAYS, AND OTHER PLACES, AND IN GLASSES OR LIGHTS FOR ILLUMINATING
PURPOSES," a communication to me from abroad by Theodore Hyatt, of
New York, in the United States of America, upon the condition
(amongst others) that I, the said John Henry Johnson, my executors
or administrators, by an instrument in writing under my hand and seal,
should particularly describe and ascertain the nature of the said Inven-
tion, and in what manner the same was to be performed, and cause the
same to be filed in the Great Scal Patent Office within six calendar
months next and immediately after the date of the said Letters Patent.
NOW KNOW YE, that I, the said John Henry Johnson, 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, reference being had to the accom,
panying Drawings, and to the letters and figures marked thereon, that
is to say :-
The said Invention has for its object the construction of frames or
gratings intended to receive glasses for the purpose of forming illumi-
nating roofs, coverings for areas, and walking surfaces for side walks
where light is required to be transmitted therethrough, and consists in
casting in such frames or grating grooves or channels, or in perforating
or partially perforating the same in rows, or in combining perforations
or partial perforations with grooves or channels in order to facilitate the
subdivision of the said gratings into separate smaller portions or sections
of any given dimensions according to the requirements of the particular
roof or structure to be erected. These gratings are by preference cast

page_text: in long narrow lengths with the dividing grooves or channels running
transversely, such long lengths being supported along cach side by
resting upon beams or bearers. The strength of the grating is preserved
by having a suflicient quantity of metal parallel to and on each side of
the breaking line which is transverse to the supporting beams or bearers.
Ench opening in the frame is glazed with glass, the whole forming a
species of compound glass and iron or other metal, which can be kept in
stock for use as required by reason of the facility afforded for breaking
or subdividing the same into parts of any given length or width. For
arched or curved roofs the said gratings may have copper or other
malleable metal wires cast along each side so as to admit of the different
sections being bent at their dividing lines to suit the curve and still
hold such sections together. The wire may be omitted when the metal
has sufficient inherent spring or flexibility to bend without breaking.
The joints along the breaking lines may be made good (if necessary)
with cement or otherwise.
And in order that the said Invention may be fully understood, I
shall now proceed moro particularly to describe the same, and for that
purpose shall refer to the several Figures on the annexed Sheet of
Drawings, the same letters of reference indicating corresponding parts
in all the Figures.
Figure 1 of the Drawings represents a sectional elevation with and
without glasses therein of my improved grating suitable for a footway;
Figure 2 is a corresponding plan of the same; Figure 3 shows a mode
of applying the said grating to the construction of an arched roof; and
Figure 4 is a detached plan of one of the forms of glasses that may be
employed.
A, B, is the grating of cast metal, and a, a, are dividing grooves or
channels which admit of the grating being readily broken up into singlo
narrow strips or into pieces, compressing two or more of such warrow
strips as circumstances may require. Each strip contains a row of light
apertures b, b, covered with glasses c, c, by preference of the forms
shown in Figures 1 and 4, that is to say, having prominent rounded
projections or knobs d, d, cast thereon, the said glasses being either
circular, rectangular, or of any other desired contour, and fitting into
scats e, e, of a corresponding form cast in the grating, into which seats
they are secured by cement of any suitable kind. In combination with
the knobs on the glass other knobs or buttons ſ,♪, may be cast on the

page_text: grating itself to afford good foothold.
It is obvious that in lieu of
casting channels or grooves a along the grating, which all but sever the
several strips, the said grating may have rows of perforations or recesses
cut therein for facilitating the subdivision thereof, there being in all
cases sufficient metal g, g (Figure 1), left along both sides of the groove
or of the row of perforations to afford the amount of strength required..
When a grating of the above-described construction is required for
curved work, such, for example, as an arched roof, then I propose to
cast therein along the two opposite edges which are at right angles to
the channels a or lines of subdivision a length of copper or other tough
and flexible wire, as shown at h, h, in Figures 2 and 3, the said wire
holding the sections together when bent or even broken at their lines of
subdivision in forming the arch, the joints in cases of absolute fracture
being made good by cement.
Having now described and particularly ascertained the nature of the
said Invention, and the manner in which the same is or may be used
or carried into effect, I would observe in conclusion that what I
consider to be novel and original, and therefore claim as the Invention
secured to me by the herein-before in part recited Letters Patent is,―
First. The manufacture and use of illuminating gratings having
grooves or channels or
rows of perforations or recesses, or their
equivalents, made therein for the purpose of facilitating their sub-
division, and having also sufficient metal left on each side of each sub-
dividing groove, channel, or row of perforations or recesses to afford the
required strength of structure, substantially as and for the purpose
herein-before described and illustrated by the Drawings.
Second. The combination with illuminating gratings constructed as
herein-before described of wire as and for the purpose set forth and
illustrated by the Drawings.
In witness whereof, I, the said John Henry Johnson have to this
my Specification set my hand and scal, this Sixteenth day of
August One thousand eight hundred and seventy-one.