IMPROVEMENTS IN ILLUMINATING GRATINGS AND IN SURFACES AND CONSTRUCTIONS MADE THEREFROM
Year: 1885

page_text: Constructions made therefrom.
I, ARTHUR WELLESLEY LAKE of Grosvenor House 13 Colville Gardens Bayswater
in the County of Middlesex Gentleman do hereby declare the nature of my inven-
tion for "IMPROVEMENTS IN ILLUMINATING GRATINGS AND IN SURFACES AND
CONSTRUCTIONS MADE THEREFROM (a communication to me from abroad by
Thaddeus Hyatt of 81 Columbia Heights Brooklyn New York in the United States
of America) to be as follows:-
"
My invention relates to illuminating surfaces and constructions such as roofs
pavements floors & that are made of gratings the apertures of which are blocked
with glasses to give light.
In the making of such constructions and surfaces the openings requiring to be
covered are for the most part, too large to be closed by a tile or gratings made in
a single casting such openings are therefore usually divided by rafters or cross-bars
into small sections or panel spaces of a size easily closed by a grating made in
a single casting.
These panel spaces whatever their size are by the common mode of construction
always closed by an illuminating tile made in one piece or casting and as such
spaces are not of uniform size this inode of construction compels the maker of the
tiles to always get his measurements before making the tiles, the result of the system
being increased cost in every direction, besides the limitation it places upon the
expansion of the industry for it is plain to be seen that work which can only be
made to order can never become merchandize; or enter into trade and commerce.
And yet there is a good and sufficient reason for the existence of the system and
I will now state it.
An illuminating tile or grating may be regarded as a perforated plate composed
of two parts viz: the portion through which light passes or the grating proper:
which is the light field of the plate and the dead-work border or margin that
surrounds the light field.
The panel spaces in the structural frame-work or foundation frame being designed
to let in as much light as possible, are formed with no subdividing cross-bars or
"purlins" as in ordinary roof construction as these would to the extent of their
number intercept the light.
Hence the tile made to close such an opening must be as nearly as possible all
light field, that is to say the light field of the tile must be practically equal to the

page_text: light-area of the panel space which would not be the case were several tiles
employed (as such tiles are usually made) for the borders of the several tiles where
they cross the panel-space would produce dead lines at such points equal to purlins
and to this extent destroy the value of the light space of the panel.
The object of my invention is to make possible the manufacture of illuminating
tiles so constructed as to permit any number of them to be employed for closing
a panel space, and yet with no loss or diminution of light thereby.
My invention consists in making the panel tile in fractional parts or sections,
without dead-work borders on their junction sides; the sections on being put
together, presenting a homogeneous light-field, in all respects equal to that of a tile
made in a single casting.
The features which constitute my invention, and that will be more fully set
forth and illustrated in my final specification, are seven in number, and as follows,
to wit:
First. Illuminating tiling or gratings made in fractional panel sections without
dead work borders on their junction sides or edges, adapted to abut directly,
together, to fill the panel spaces, without sacrifice of light.
Second. Illuminating tiling or gratings made with light-holes arranged on the
honeycomb principle; and divided into fractional sections directly across the field
of light-holes, without dead work borders on the dividing or junction lines; and
adapted to abut directly together, and form a continuous light field in panel-
spaces.
Third. Illuminated tiling, or gratings, made with light-holes arranged on the
honeycomb plan, or in groups of oblique angled triangles, and disposed in parallel
lines transversely to the light-field; said tiling being divided into fractional sections
in transverse lines parallel with and outside of the lines of light-holes, and adapted
to abut directly together to form a continuous light field in panel. spaces.
Fourth. Illuminating tiling or gratings made with an underlying sustaining
grating of cast iron or other supporting material, and an overlayer or facing of
concrete or hydraulic cement, and divided into fractional sections adapted to abut
together to fill panel spaces: said sections being made without dead work borders
on their junction-sides; and presenting a deep raw or unfinished edge of hydraulic
cement at the junction edges adapted to abut together and be secured in a
homogeneous manner with hydraulic cement when laid in their panels.
Fitth. Illuminating tiling made in fractional sections fitted into panel spaces
with their junction edges abutting and secured together and to the panel frame or
foundation by cementation.
Sixth. Illuminating tiling made in fractional sections, fitted in panel spaces, and
secured to the panel frame, or foundation and to each other by hydraulic cement
deposited in the junction seams of the fractional sections, and in the construction
seans of the panel frame or foundation.
Seventh. Illuminating tiling made with a hardened cement or concrete surface,
and divided into fractional sections in lines crossing the light-field without dead-
work borders, and presenting on said dividing lines, raw edges of the cement
adapted to abut directly together, and be secured in a homogeneous manner by
similar hydraulic cement in a plastic state, when the fractional sections are laid
into panel spaces.
In order to produce the best effect, I arrange the light-holes in the fractional
sections on the honeycomb principle, or in groups of oblique angled triangles; and
I also arrange the light holes in lines running cross wise to the panel or parallel
with the junction sides of the fractional sections instead of longitudinally with the
tile in the usual way of the one casting tiles. I also prefer to construct the
fractions of the tile of iron or equivalent material and face them with concrete or
hydraulic cement-and in laying and securing them in place I fit them into the
panel spaces with their junction edges abutting or approaching; and I then fill
the joint seams between the panel tiles and the rafters or tile supports of the panel
frame with cement; preferably hydraulic cement which uniting with the cement.

page_text: edges of the fractions and with the iron of the structural frame work joins the
fractions in a homogeneous manner and binds the whole series of fractional gratings
within the panelled frame work, in an exceedingly secure, simple and inexpensive
mode, without the necessity of bolting or mechanical fastening as heretofore
employed; and at the same time produces the appearance of illuminating work
made of the one casting panel tiles.
Before proceeding further I will first explain the meaning of the technical terms
which I shall employ herein under and in the Final Specification which is to
follow and which is as follows viz:—
1st Combination Tile "-means a tile composed of fractions or parts put together
with the effect of resembling the tiles in common use made in a single casting.
'2nd << Fractional Gratings - mean gratings formed with naked junction sides:
that is to say with junction sides made without dead work borders.
"
3rd Joint Seams "-mean seams between fractional gratings where the junction
sides thereof come together in forming Combination Tiles.
"
4th "Construction Seams '-mean seams between tiles and tile supports in
forming roofs or surfaces.
5th "Construction Surfaces
illuminating gratings.
"
-mean roofs floors pavements and surfaces made of
6th "Illuminating Tile"-
'-means a one casting tile or continuous Light Field
grating made and shaped for construction purposes, in contra-distinction to vault
covers, or gratings made for closing coal holes.
7th "Light Field "-means the open work or grating portion of an illuminating
tile.
8th "Dead work border "--means the blank portion of a tile that surrounds the
light field.
9th "Panel-tile "-means (when employed in connection with roof, floor and
pavement construction) the illuminating portion or section of a construction surface
contained between any two of its rafters or tile supports.
10th "One casting-Panel tile "-means the section of a construction-surface
contained between any two of its rafters or tile supports when such section is made
of but one tile or light-field.
11th Sectional or Panel spaces "-mean the spaces or sections into which an
opening is divided by rafters or tile supports preparatory to being covered by
tiles.
12th Material "-means a substance equivalent to hydraulic cement for pro-
ducing like construction results.
13th "Concreted Gratings' ' mean a perforated plate or grating overlaid or
faced with cement concrete or material.
The gratings for my improved combination tiles may be made as usual of cast
iron, with the openings thereof blocked with glasses secured therein in the usual
way and with the top surface thereof either smooth or studded with knobs between
the glasses, or the gratings may be made of any other suitable material, and with
any desired formation of the upper surface.
I greatly prefer however to make my fractional tiling with an underlying.
grating or base made of cast iron and an overlying facing of concrete or hydraulic
cement or of equivalent material which secures the glasses in the grating and also
at the same time forms the weather surface of the tile.
This method of construction being peculiarly adapted for my fractional grating
tiles, has great advantages therefor especially in the laying and fastening of the
fractions in the panel spaces by the cementing method which I employ for the
fractions will not only be without dead work borders on their junction sides but
will also have a raw or unfinished face of hydraulic cement at the junction edges,
which will be of a good width or depth vertically, and will therefor be admirably
adapted to unite with the cement placed between the said edges when fitted.
together.

page_text: Combination tiles thus made are easily united with the panel spaces of the
foundation frame, being placed therein in small sections; and the junction sides
closely approaching each other, the light fields of the several fractions unite and
combine so as to appear like one continuous light field in all respects equal, and
similar to those of the one casting panel tiles.
In this mode of construction the cement will not only fix each fraction firmly to
the sides of the panel spaces of the foundation frame, but will also unite the
fractions together into one uniform tile, and if the cement employed be hydraulic
cement, similar to the facing of the fractions,--which is what I recommend-the
fixation of the tiles will be homogeneous and particularly secure and solid, and
each panel will present the appearance of being filled with a continuous tile made
of a single casting; thereby securing to the Art of Patent light manufacture and
construction very great advantages.
Hence, by this system of Fractional gratings-construction, and cement-fixation,
the necessity of bolting the tiles to the structural frame-work as usually performed,
may be entirely dispensed with, as the cement fixation described, will serve both to
render the joints water-proof and secure the tiling at the same time permanently
in place, which is a most important advantage of the construction.
In the one-casting Panel-tile system of construction, on the contrary, bolting
cannot be dispensed with on account of the usually irregular and warped condition
of such large castings, especially when made thinner than usual. The one-casting
tiles too, when made of unusually large size are very apt to crack and thus spoil
the casting; to the great loss of the maker, or with additional cost for castings put
upon the manufacturer of the lights. But when the tiling is made of fractional
parts, as herein described, these fractions being small may be made very light, and
exceedingly accurate and true; free from warpage and perfectly flat, so as to set
perfectly level and fair one with another when placed in position within the panel
spaces of the foundation frame; and the sides of the fractions vertically being
relatively deep, an area of adhering bonding surface for the cement is presented on
every side by which to fasten the fractions to each other and all to the structural
frame work as aforesaid.
In addition to the advantages thus set forth, my new system of manufacture and
construction furnishes the tiling in a portable shape, easy to be handled in moving
and laying, thus requiring less labor in their application to use than is the case
with the large and heavy one-casting tiles. The loss too, from imperfect castings
will be less. Again, they are more readily packed for shipment or transportation.
Furthermore, they may be manufactured at the cheapest centers of the iron
industry, where castings in quantity are manufactured at the lowest prices; may
.be in large quantities in regular definite sizes and shapes, easily catalogued, and
classified and adapted to all kinds of architectural work; thus capable of being
kept in stock by Merchants of "builder's hardware" like locks, and other materials,
screws, hinges, nails &° and be thus furnished and sold by dealers along with other
building materials as regular articles of trade and manufacture.
With all these advantages it is readily seen that the effect of my invention is to
raise the Patent light manufacture from the level of a mere local handicraft into
an important manufacturing Industry allied to commerce and capital and capable
of furnishing work for tens and hundreds of pairs of hands where now but one or
two are employed.
As an addition practically to the World's Industries my Invention.
be regarded in the light of a boon to all mankind.
may therefore

page_text: Improvements in Illuminating Gratings and in Surfaces and
Constructions made therefrom.
I ARTHUR WELLESLEY LAKE of Grosvenor House 13 Colville Gardens Bayswater
in the County of Middlesex, Gentleman, do hereby declare the nature of this
invention (a communication to me from abroad by Thaddeus Hyatt of 81 Columbia
Heights, Brooklyn, New York United States of America) and in what manner the
same is to be performed to be particularly described and ascertained in and by the
following statement :-
My present invention relates to illuminating surfaces and constructions such as
roofs pavements floors & that are made of gratings, the apertures of which are
blocked with glasses to give light.
Heretofore illuminating tiles or gratings have been always made to order in
special sizes and shapes to suit the particular work in hand according to the plans
of architects in each particular structure. Usually the opening to be covered by
the illuminating tiling is divided into large panels or sectional spaces each one of
which is enclosed by a tile made of a single casting in order to secure the greatest
amount of light which would be lost if the panel-spaces were fitted with a number
of small tiles each made with the usual surrounding dead work borders or margins.
Now the great object of my present invention is to enable the manufacture of
illuminating-tiling to be greatly cheapened, facilitated and improved in such a way
that it can be manufactured in large quantities in joinable sections or fractions of
definite sizes and forms, which may be kept in stock, and sold as regular articles
of trade or manufacture, suitable for all kinds of architectural plans or structures,
and which fractional pieces can be readily joined together in the panel-spaces of
the structural frame-work without loss of light, and without requiring special
castings or formations as heretofore. Tiling made in this way will be obviously
much cheaper and more convenient and more perfect, and admit of wider and more
general use for when made in such small fractional and joinable sections the form
of the tiling can be made much more accurate on account of reduction of warpage,
and reduction of failures in casting; and when so made will be more portable, and
can be much more easily and perfectly laid, thereby effecting a great and most
desirable improvement in the art.
According to my present invention therefore, I make illuminating-tiling in
fractional sections or parts without dead work borders on their juncture sides or
edges so that said fractions can be junctured directly together in the panel-spaces,
to form complete illuminating panel-tiles without loss of light, and in a manner
more easy and perfect than would be the case with the single or one casting panel-
tiles. In order to produce the best effect I arrange the light holes in these
fractional sections on the honey-comb principal, or in groups of oblique-angled
triangles, and I also arrange the light-holes in lines running crosswise to the panel
or parallel with the junction sides of the fractional pieces instead of longitudinally
of the complete tile or panel as has been usual. I also prefer to construct these
fractional gratings of iron or other suitable material overlaid or faced with concrete

page_text: or hydraulic cement, and in laying and securing the fractions in place I fit them
into the panel-spaces with their junction sides abutting or approaching, and I then
fill the joint seams between the fractions and the construction-seams between the
panel-tiles and the rafters or tile-supports of the panel frame with cement-
preferably hydraulic cement-which, uniting with the cement edges of the fractions
and with the iron of the supporting or foundation frame, joins the fractions in a
homogeneous manner, and at the same time binds the whole series of fractional
gratings to and within the paneled frame-work in an exceedingly simple and
inexpensive manner, without the necessity of bolting or mechanical fastenings as
heretofore employed, and at the same time produces the appearance of illuminating
work made of the one-casting panel-tiles.
My invention therefore. consists in the several features above outlined as
hereinafter fully set forth.
In specifying my invention I shall first refer to and describe the common system
of tiling, in order that my present improvement may be better understood and
appreciated and distinguished therefrom.
In the annexed drawings, Figures 1 to 8 illustrate the old or prevailing system
previous to my present invention. Fig. 1 is a plan view indicating the structural
opening or space to be covered or tiled. Fig. 2 is a similar view with the opening
divided by cross bars or rafters into panel-spaces. Fig. 3 represents a small
illuminating-tile made in the ordinary manner with a dead-work border or margin
on all sides; and Fig. 4 represents a similar tile of larger size or a one-casting
panel-tile as heretofore and commonly made to be used singly in panel spaces.
The light-holes in these tiles are square and arranged in squares as shown in the
figures. Fig. 5 represents part of a structural frame-work filled with tiles like
those in Figs. 3 and 4. Figs. 6 and 7 illustrate tiles like those in Figs. 3 and 4,
but with light-holes arranged on the honey-comb principle and in lines lengthwise
of the panel-tile; and Fig. S is a plan of part of a structural frame work filled with
tiles of the last-named kind. Figs. 9 to 18 illustrate my present improvement.
Fig. 9 is a plan of an end, and Fig. 9 of a middle, fractional tile or grating formed
with square light-holes arranged in squares and made without dead-work borders
on their junction sides or edges. Fig. 10 shows a portion of a paneled space or
frame-work covered by combination-tiles made of fractional gratings like 9 and 9.
Figs. 11 and 12 illustrate two forms of my improved fractional gratings made with
light-holes on the honey-comb plan running in longitudinal lines, but having
different forms of junction edges. Fig. 13 shows a fractional grating made with
light-holes on the honey-comb plan, but running in transverse lines parallel with
the junction sides of the fractions. Fig. 14 shows a plan of a paneled space or
frame-work fitted with combination-tiles made of the three aforesaid kinds of
fractional gratings. Figs. 15, 16, 17 and 18 illustrate that part of my invention
which relates to joining fractional gratings to each other and the whole to the
structural framework without bolting or inechanical fastening. Fig. 15 represents
combination-tiles combined with the structural frame work without mechanical
fastening. Panel-space b¹ shows the fractional gratings in place before the cement
is put into the joint and construction seams, and panel-space 62 shows the sanie
when fixed by the cement. Fig. 16 represents a section on line xx of Fig. 15,
showing the sides of the fractional gratings in elevation; Fig. 17 represents a
section on line y y of Fig. 15, showing the ends of the fractional gratings in
elevation, and Fig. 18 is an elevation showing the junction side of a fractional
grating made as shown in Figs. 11 and 12.
Before proceeding to the general description I desire to define the special terms
which I shall employ therein; and,
"
First, "combination-tile' means a tile composed of fractions or parts put
together with the effect of resembling the tiles in common use made in a single
casting.
"
Second, "fractional gratings mean gratings made naked that is to say,
without dead-work horders on their junction sides

page_text: "
Third, "joint-seams means scams between fractional gratings where the
junction sides thereof come together in forming combination-tiles.
"
Fourth, "construction-seams' mean seams between tiles and tile-supports in
forming roofs or surfaces of illuminating-gratings.
Fifth, "construction-surfaces" mean roofs, floors, pavements, and surfaces made
of illuminating-gratings.
دو
Sixth, illuminating-tile means a one casting tile or continuous light-field grating
made and shaped for construction purposes in contradistinction to "vault covers
or gratings made for closing coal-holes."
Seventh, "light-field" means the open-work or grating portion of an illuminating
tile or grating.
the blank portion of a tile that surrounds
"
Eighth, "dead-work border' means
the light-field.
Ninth, "panel-tile" means (when employed in connection with roof, floor and
pavement construction) the illuminating portion or section of a construction surface
contained between any two of its rafters or tile-supports.
"
Tenth, "one-casting panel-tile means the section of a construction surface
contained between any two of its rafters or tile-supports when such section is
made of but one tile or light-field.
"
Eleventh, "sectional or panel spaces' mean the spaces or sections into which
an opening is divided by rafters or tile-supports preparatory to being covered
by tiles.
Twelfth, "material" means a substance equivalent to hydraulic cement for
producing like construction results.
Thirteenth, "concreted grating" means a perforated plate or grating overlaid or
faced with hydraulic cement concrete or material.
To understand what my improvements mean and their importance, it is necessary
to understand what is meant by the "one casting" panel-tile system, which I will
now proceed to explain, and illustrate by the drawings.
Figs. 1 to 8 illustrate the system of patent-light construction now in general use,
and which was invented by me, and introduced into public use thirty-five years
ago, since which time it has remained in substantially the same condition. Fig. 1
represents an opening that requires to be covered over by illuminating-tiles. This
opening may be regarded as at the rear of a building or at the front. A A, the
face-line of the building; B, the opening; C, the coping around the opening.
Fig. 2 represents the opening when subdivided by cross-bars or rafters into
sectional or panel spaces; a a, the rafters or cross-bars; b. b, sectional or pane!
spaces.
Fig. 3 represents a small illuminating-tile wherein the light-holes are square, and
arranged in straight lines that cross each other at right angles; D, the light-field
of the tile; c c, dead-work borders of the tile.
Fig. 4 represents a large or one-casting panel-tile made with square light-holes.
Fig. 5 represents a portion of an opening covered by tiles similar to Figs. 3 and 4.
Sectional space b¹ illustrates the effect of employing several tiles of the ordinary
kind to close such a space. Sectional space b* illustrates the effect of employing but
one tile to close such a space.
Fig. 6 represents a small illuminating-tile made with light-holes grouped in
clusters of oblique-angled triangles.
Fig. 7 represents a large or one-casting panel-tile similar to Fig. 6.
Fig. 8 represents a portion of an opening covered by tiles similar to Figs. 6 and 7.
Figs. 1 to 8 illustrate the system of patent-light manufacture and construction in
use, and show the features that constitute both its merits and defects, both features
of which must be fully understood in order to be able to comprehend and appreciate
the nature and value of my improvements.
Fig. 1, an opening to be covered by illuminating-gratings, is designed to
illustrate the practical fact that the size of openings to be covered thus is altogether
too great to admit of being closed by any tile capable of being made in a single

page_text: casting, such openings being in general from eight to sixteen or twenty feet long,
and in width varying from three to ten or twelve feet. Fig. 2 therefore represents
the opening divided by rafters or tile supports into sizes of convenient width and
length to be closed by gratings that can be made in a single piece or casting. Now,
if we consider Fig. 2 to represent a roof space divided into sections b. b. b. by the
rafters a a a, then were this ordinary roof construction made with no regard to
light, we should have the rafters crossed by purlins, cutting up and subdividing all
the sectional spaces; but light being the purpose of the construction shown by the
figures, the sectional spaces b b are left entirely open between the rafters to let in
as much light as possible, and the illuminating tiles manufactured to close such
sectional spaces are made with direct reference to this prime necessity of the
construction policy. Figs. 3, 4, 5 are designed to illustrate this point. Fig. 3
represents an illuminating tile as ordinarily made, but so small that three of them
are required to close one of the panel or section spaces of Fig. 5 as shown at b¹.
Now as by the common mode of constructing these gratings they are made each
with a dead work border, c c c c, which entirely surrounds the light-field D of the
tile on its four sides, as seen in Fig. 3, it follows, as illustrated at b', Fig. 5, that
the employment of such tiles is directly at variance with the construction policy of
illuminating-roof making in which purlins are inadmissible, for it is plain to be
seen that the dead-work border of tile No 1 in sectional space b', Fig. 5, where it
abuts with the dead work border of tile No 2, produces a dead-line and loss of light
equal to an equivalent interception of light by a purlin; and this loss of light in
each one of the sectional spaces, when so closed by a number of small gratings of
ordinary make, is augmented directly in proportion to the number of such tiles
employed, as is further illustrated in b¹ Fig. 5 where the dead-work borders of
tiles 2 and 3 abut together. It follows from this that the fewer the tiles to each
one of the sectional spaces the greater the light and consequently that a single or
one-casting tile is best of all when manufactured in the common way. This fact
has become so generally recognized by architects and the public generally that the
one-casting panel-tile system of manufacture and construction is now the universal
mode the country over, and no manufacturer of patent lights has any chance of
success unless he conforms to this established usage. At the same time it has been
always felt to be a great drawback to the industry that illuminating-tiles cannot
be manufactured to stock sizes and kept on hand to be sold as merchandise. Any
manufactured article that can be kept in stock can be always manufactured more
cheaply and to better advantage than when made to order. Making to order means
paying the highest wages and buying the raw materials in the dearest market and
this enhances prices and restricts use and consumption.
Sectional space 68, Fig. 5, illustrates the one-casting panel-tile system of con-
struction, the principal of the construction as illustrated by the figure being a
closure for the sectional space containing a light field substantially co-extensive
with the area of the section of space covered by the tile. Panel-space b¹, Fig. 5,
contains three tiles, and consequently three light-fields with necessarily two dead-
work border-divisions running across the panel-light space of the structural frame-
work, and with therefore a consequent and equivalent loss of light-power; but
panel-space b, containing but one tile, and therefore but one light-field secures
thereby the whole of the available light power of the sectional or panel space
contained within the structural frame-work to which the illuminating tiles are
fixed. This one casting panel-tile mode of construction secures the object of the
invention as to light-power, but at a great sacrifice to the art as an industry,
confining it to the condition of a mere handicraft, with but little, if any, importance
beyond its own immediate centers of production and manufacture.
Drawing Fig. 5, reveals the defects of the present system, and at the same time
reveals the primary cause-to wit, an illuminating grating or light field entirely
encircled by a dead-work border--the consequence of which as shown at b¹ is
that the sectional or panel space of the foundation-frame thus closed is not only
disfigured by the dead-lines of the dead-work borders where the cross the space

page_text: between the light-fields of the separate tiles, but the light-power of the section.
space to this extent also suffers a diminution of its illuminating power.
Figs. 9, 9, and 10 illustrate one form of my improved fractional gratings and
construction. Fig. 9 represents a grating in all respects the same as Fig. 3, with
the exception of being made with no dead-work border on its matching or junction
side, which in this case is on its lower side, the grating being designed to form the
end plate of a combination-tile. Fig. 9ª represents Fig. 9 with the top dead-work
border removed, thus producing two junction sides, this grating being designed to
form a middle plate in a combination-tile.
Fig. 10 illustrates the construction effect produced by the employment of my
improved fractional gratings, an additional grating, (N° 4 Fig. 10.) containing six
glasses, being obtained, as may be seen by comparing the four gratings contained
in panel-spaces b¹ b, Fig. 10, with the three tiles of ordinary make contained in
panel-space b¹, Fig. 5. It will also be seen that the combination-tile closures
of panel-spaces b₁ 62, Fig. 10, contain each the same number of glasses as is
contained in the one-casting panel-tile that forms the closure to b³, Fig. 5,
The kind of fractional gratings shown in Figs. 9, 9 and 10, wherein the light-
holes are arranged in straight parallel lines crossing each other at right angles or in
squares, are of comparatively easy formation as to junction sides; but more than
eighty per cent of all the illuminating grating constructions in use are made of tiles
wherein the light-holes are grouped in clusters of oblique-angled triangles; or on
the honey-comb principle, which kind of tile is much more difficult to divide into
fractional sections or parts, and at the same time form good junction sides that will
not be embarrassed by the light-holes bordering the junction edges, and that like-
wise may be easily and readily fitted together.
'Figs. 6, 7, and 8 represent the same tiles and constructions shown by Figs. 3, 4,
and 5, with the difference only as to the shape and arrangement of the light-holes.
As ordinarily made the light-holes in such tiles as are represented by Figs. 6 and 7
run lengthwise with the tile in parallel lines, the holes of one row breaking joint
with those of the adjoining rows to right and left. In construction results the
effect is the same as have pointed out, whether tiles made on the honey-comb
plan of light-holes or the others are employed; but inasmuch as the popular tiles
and constructions in use are made with light-holes arranged on the honey-comb
method, it is of great consequence to the success of the fractional gratings system
of construction and manufacture to be able to make easily-joinable fractions with
light-holes similar to those of the popular one-casting panel-tiles in common use,
and this is accomplished with different degrees of advantage by the forms of the
fractional gratings shown in Figs. 11, 12, 13, 14.
Figs. 11 and 12 are practically cross-sections of an illuminating-tile made
according to the common mode of manufacture, wherein the light-holes run length-
wise with the tile, as illustrated by Fig. 7. Fig. 12, represents a fractional grating
as though it were a section of Fig. 7 made by cutting through the light-holes.
Fig. 11 represents a section of Fig. 7 made by cutting around the light-holes.
Fig. 13 represents a fractional grating with the light-holes so disposed therein
as to run crosswise to the tile on the fractions being joined together and with the
junction edge or dividing line running straight across parallel with and outside of
the outer line of holes.
It may now be noted by reference to Fig. 14 that when the fractional sections
are made with the light holes running in longitudinal lines the lines of division or
junction lines must cut either through or around the holes and hence form edges
which are more difficult to fit together or require some of the glasses to be inserted
when the tiles are laid. Thus the objection to the form shown in Fig. 12 where
the junction line bisects the light-holes, (shown more definitely by the combination
tile closure of panel space b', Fig. 14), is that one line of glass has to be set in at
each junction line when the fractional tiles are laid in place, and the objection to
the form shown in Fig. 11, where the junction edge is deeply scalloped, is that such
edges are not easily and readily cemented together. It will be seen, however, that

page_text: in Fig. 13, where the lines of light-holes run crosswise parallel to the lines of
fractional division, the junction edges can run in a straight line across the tile
and outside the outer line of holes, which as seen in Fig. 14, produces a form
of fractional grating which is much more perfect and simple than the others and
is more easily fitted together.
Now the gratings for my improved combination panel-tiles may be made as
usual, of cast iron, having its perforations fitted with glasses secured therein in the
usual way, and with the top surface of the casting either left smooth or studded
with knobs around the glasses in the ordinary way; or, the gratings may be made
of any other suitable material and with any desired formation of the upper surface.
I greatly prefer, however to make my fractional tiling with an underlying grating
or base of cast-iron and an overlying facing of concrete or hydraulic cement or
material, which, if desired may fasten the glasses to the grating, and also at the
same time form the walking or non-condensing surface of the combination-tile as
shown in Figs. 11 to 14, but seen best in Figs. 15, 16, 17, and 18, where d indicates
the iron or other base, e the light-holes and f the concrete facing. This method of
construction is specially adapted for my fractional tiling and has great advantages
therefor, especially in the laying and fastening of the fractions in their panels by
the cementing method which I employ. Thus, by referring to Figs. 11 to 18 it will
be seen that when the fractional gratings are made as described, not only will they
be without deadwork borders on their junction sides, but will also have a raw or
unfinished edge of hydraulic cement at the junction edges which will be of a good
width or depth vertically as illustrated by Figs. 16. 17 & 18 which represent side
elevations of fractional gratings overlaid with cement, 16 and 17 representing
gratings wherein the rows of light holes run transversely to the combination tile,
as seen in Fig. 15, and as a consequence produce junction sides with a raw edge of
cement having no break in it by reason of the light-holes, whereas, when the light
holes run in the ordinary way, as shown in Figs. 11 and 12 and in Fig. 14 in
panels b' and 62, the raw cement edge of the fractional grating is broken on the
junction line, as shown in Figs. 18, where the light holes e e break the continuity
of the raw concrete, and to this extent interfere with the perfection of the cement
bond between the fractions when they are united to form the combination tile.
The advantage of concreting the fractional gratings is thus made manifest, and the
further advantage of running the light holes transversely to the combination tile is
clearly shown.
g indicates the cement joint seams between the fractional gratings, and g' indi-
cates cement construction seams between the same and the structural frame-work
that supports them.
It may therefore be now understood referring to. Figs. 15 to 18, that the
fractional tiles made as described may be easily fitted into the panels of the
foundation frame or structure, where their junction edges may closely approach to
form one continuous combination tile to cover said panel-space with the greatest
possible amount of light admission and when so placed cement can be then
deposited in the sides of the fractional gratings in the joint seams and between
the sides of the combination-tiles (thus formed in loco) and the blades of the rafters
or supporting crossbars, and between the ends of the combination tiles and the
marginal surrounding border of the structural frame- work as shown at g and g¹ in
Figs. 15, 16 and 17 which cement will not only fix each fraction firmly to the
borders of the panels of the foundation frame, but will also unite the fractions
together into one uniform tile; and if the cement employed be hydraulic cement,
similar to the facing of the fractions (which is what I recommend) the fixation of
the same will be homogeneous and particularly secure and solid and each panel will
present the appearance of being filled with one continuous tile of equivalent value
in both use and beauty to the one-casting tiles commonly employed, but more
cheaply and easily made thereby producing very great advantages to the art of
illuminating-tile manufacture; hence by this system of fractional construction and
cement fixation the necessity of bolting the tiles to the framework as usually

page_text: performed may be entirely dispensed with the fractions being small and light being
capable of being fixed by cement, and, being small, are easily cast without warpage,
and therefore need no bolting to the frame-work to take them out of "wind,"
whereas the one-casting tiles being large and warped require bolting to bring them
level and straight upon their beds in the structural frame-work. Hence my
invention of fractional gratings and cement fixation as described serves both to
render the joints water-proof and at the same time to secure the tiling permanently
in place which is a most important advantage in the art of patent-light con-
struction. On the contrary, as has been already said, in the one-casting panel-tile
system of construction bolting cannot be dispensed with on account of the usually
irregular or warped form of the castings which require bolting to bring them level
and keep them so in the panels.
It will therefore be seen that the system of tiling herein described presents a
great improvement over the old systein in many important particulars. Thus when
the tiling is made in small pieces or sections as fractions of a combination tile such
fractions can be manufactured very cheaply as stock material and being small can
be cast very accurately and as perfectly flat as stove-castings, true and free from
the warpage that is unavoidable in large castings thus enabling the fractional
gratings whatever the number of them used in the construction, to form a uniformly
level surface by being simply laid in position one with another in this way saving
all the labor of fitting bolting and drilling now necessary in the one-casting tile
constructions; secondly the loss from imperfect castings will necessarily be inuch
less than is the case with single panel castings; thirdly the fractional tiles will be
very portable and may be very easily handled in moving and laying the same, and
will thus require less labor than would be the case with large and heavy castings;
fourthly, they can be easily packed and transported; fifthly, they may be
manufactured in large quantities in regular definite sizes and shapes which may
be easily catalogued and classified and adapted for all kinds of architectual work
and may be thus kept in stock and sold as regular articles of merchandise instead
of being required to be made to order for each special job, as heretofore; finally,
with all these advantages of economy and efficiency the new system gives the
greatest possible amount of light in each panel, which with the other results set
forth renders my invention an important and novel advance in the art of patent
light manufacture and construction.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I declare that what
I claim is
1. Illuminating tiling or gratings made in fractional panel-sections without dead-
work borders on their junction sides or edges and adapted to abut directly together
to fill the panel spaces without sacrifice of light substantially as set forth.
2. Illuminating tiling or gratings made with light-holes arranged on the honey-
comb principle and divided into fractional sections directly across the field of
lightholes without dead work borders on the dividing or junction lines and adapted
to abut directly together and form a continuous light-field in panel-spaces substan-
tially as berein shown and described.
3. Illuminating tiling or gratings made with light-holes arranged on the honey-
comb plan or in groups of oblique angled triangles and disposed in parallel lines
transverse to the light-field, said tiling being divided into fractional sections in
transverse lines parallel with and outside of the lines of light holes, and adapted
to abut directly together to form a continuous light-field tile in panel-spaces
substantially as set forth.
4. Illuminating tiling or gratings made with an underlying sustaining grating of
cast iron or other supporting material, and an over-lying facing of concrete or
hydraulic cement, and divided into fractional sections adapted to abut together to
fill panel spaces said sections being made without dead-work borders on their
junction sides and presenting a deep raw or unfinished edge of hydraulic cement-

page_text: at the junction edges adapted to abut together and be secured in a homogeneous
manner with hydraulic cement when laid into their panels substantially as herein
set forth.
5. Illuminating tiling made in fractional sections fitted into panel. spaces with
their junction edges abutting and secured together and to the panel-frame by
cementation substantially as herein set forth.
6. Illuminating tiling made in fractional sections fitted into panel-spaces and
secured to the panel frame and to each other by hydraulic cement deposited in the
junction-seams of the fractional sections and in the construction-seams of the
panel frame substantially as set forth.
7. Illuminating-tiling made with a hardened cement or concrete surface, and
divided into fractional sections in lines crossing the light field without dead-work
borders, and presenting on said dividing lines raw edges of the cement, adapted to
abut directly together and be secured in a homogeneous manner by similar hydraulic
cement in a plastic state when the fractional sections are laid into panel spaces
substantially as herein shown and described.
TALA
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