IMPROVE- MENTS IN ARCHITECTURAL AND ENGINEERING CONSTRUCTIONS AND MATERIALS, AND IN MEANS, MODES, AND PROCESSES CONNECTED THEREWITH."
Year: 1877

page_text: LETTERS PATENT to Thaddeus Hyatt, of 66, Gloucester Gardens, Hyde Park,
London, in the County of Middlesex, Inventor, for the Invention of "IMPROVE-
MENTS IN ARCHITECTURAL AND ENGINEERING CONSTRUCTIONS AND MATERIALS,
AND IN MEANS, MODES, AND PROCESSES CONNECTED THEREWITH."
PROVISIONAL SPECIFICATION left by the said Thaddeus Hyatt at the
Office of the Commissioners of Patents on the 2nd August 1877.
THADDEUS HYATT, of 66, Gloucester Gardens, Hyde Park, London, in the County
of Middlesex, Inventor. "IMPROVEMENTS IN ARCHITECTURAL AND ENGINEERING
CONSTRUCTIONS AND MATERIALS, AND IN MEANS, MODES, AND PROCESSES CON-
NECTED THEREWITH.'
"
My Invention relates to improvements in bridge, beam, and building constructions,
chiefly with respect to economy of metal, by the use of hydraulic cement or con-
crete as a strengthener of metal, and a substitute for that portion of it designed in
ordinary structures to resist compression.
My Invention also relates to means, modes, and processes of construction to render
buildings safe against fire, and to improved methods for lighting and ventilating the
same, and improving the draught of chimnies.
My Invention also relates to a new and cheaper method of making open gratings
for walking surfaces and for guards, fences, railings, and similar purposes.
My Invention also relates to a new method of constructing buildings of metal
and concrete, the metal producing and distributing tensional or fibrous strength and
coherence throughout the mass, so that the roof instead of being a load or weight on
the walls, becomes one with them. Also to making illuminating concrete pavement
slabs with movable centers for coal-hole plates.
Bridge Constructions.-Portland cement has been applied to the interior of
iron vessels to keep the metal from rusting. My improvement in the construction

page_text: my
of bridges, according to one part of my Invention, consists in the application of
Portland or equivalent hydraulic cement, lime, or concrete, as protection against rust,
and also against the action of the sun's rays upon the metal; also to render the
structure more fireproof; and, finally, to cheapen the construction by the use in part
of concrete or cement as the compressive material upon the principle of
concrete
beam constructions for building purposes; except that for bridges, I prefer to make
the top in part of metal, to avoid the great weight of all concrete, nevertheless, by
increasing the height of the bridge the weight of concrete may be lessened; a part
of my Invention to lessen the weight of the concrete bridge consists also in making
the web of open-work concrete, somewhat on the principle of a lattice girder, the
concrete being so arranged and distributed in connexion with the vertical ties or
suspenders as to take the diagonal or oblique thrusts. While not confining myself
to any special pattern of metal skeleton as the core for such a concrete bridge, but
adopting any form most satisfactory to the engineer, I still prefer to make the
bridge in general according to the principles of construction heretofore set forth in
my Patents for concrete beams, that is to say, using the metal chiefly in tension in
the form of a flat tie or flat ties and verticals, or in the gridiron-tie forin, that is to
say, in the form of a pack of leaves or blades of metal placed edgewise and threaded
upon rods. I also prefer to employ such gridirons at intervals between the bottom
and top of the bridge to increase the rigidity of the web. The top rail or
flange may contain whatever proportion of metal may be desired; the more
the metal, the less the concrete; the less the metal, the more the concrete. The
skeleton may be placed in position by any well-known mechanical means em-
ployed in bridge construction, and is to be then coated over or imbedded in
concrete or cement, the same being applied in any well-known manner and by the
aid of ordinary or special moulding apparatus suited to the purpose.
Gridiron-Tie Beams.-The object of this part of my Invention is to economise
the erection of fire-proof buildings, by making the materials in handy shape so as to
be merchantable and readily obtained; and my improvement, which has reference to
the employment of thin metal blades placed edgewise and arranged in packs, con-
sists in manufacturing the same in beam form of convenient sizes and of suitable
weights for varying spans as required for building purposes, the leaves of metal
when thus put together being termed by me gridiron-tie beams. These beams are
made by threading any required number of bars or blades of metal upon rods having
heads at one end, the blades being kept at the proper distances apart by thimbles or
otherwise, and when all are in position, I then either upset the ends of the rods
where no heads are, or I use rods previously cut with screw threads, and I then
tighten up and secure the pack of metal blades by means of nuts. These gridiron
beams I propose to make and put upon the market as a new manufacture.
Another part of my Invention consists in making as a new manufacture a special
sort of hoop iron as tie metal for combination with concrete, to wit, according to
one method of manufacture I cross-corrugate the metal so that when in position the
corrugations shall lie in the concrete at right angles or crosswise to the length of the
beain.
According to another method I perforate the flat tie-metal or hoop iron with holes
at convenient distances apart, say, 2" to 6", and then drive cut wires into and
through such holes, the wire being sufficiently thick to bind when thus driven in,
the same also projecting equally from both sides of the metal, an inch or more; the
object of the construction being to prevent the ties from slipping in the concrete
when the beam is under strain.
Another part of my Invention having reference to concrete beams made in sections
or brick form, consists in forming such bricks with indents or recesses in the sides
thereof, so as to be easily attached to the tie or skeleton of metal; by employing
this form of brick the skeleton may be first placed in position, and the bricks then
cemented together upon them with the effect of enclosing the tie within the body
of bricks; or the bricks are formed with a projecting top to rest upon the tie, the
body of the brick going down behind it, so that on cementing the ranges together,

page_text: wedge-shaped channels are thereby formed under the ties, which are afterwards
made good by cement.
Another part of my Invention relating to composite constructions of concrete
and tie metal consists in putting the metal in excess to prevent sudden rupture,
such a floor or other structure bending before breaking, and thus giving timely
warning of danger.
Another part of my Invention has reference to the want of holding power in
plain flat ties, in concrete constructions, when the tie is located almost at the bottom
of the concrete. I have that when a sufficient layer of concrete is put under-
neath as well as above the tie, that the metal holds well, except that it is advisable
to secure it at the ends. I have also found that at least two inches of concrete is
required underneath a tie to protect it well against fire; and my improvements in
making floors, roofs, and walking surfaces by the union of concrete and tie metal
consists then in producing a holding power or grip on the tie by means of the fire-
proof layer of concrete made use of underneath the metal to protect it against fire.
Another part of my Invention consists in making fireproof in two separate
layers or horizontal sections, the upper half forming the floor proper or walking
surface to the room or space above it, and the lower half or section forming the
ceiling to the room or space beneath it, an air space of one or more inches being
formed between the two; the lower half or section becomes then a shield in case of
fire to the loaded floor above, and may bend, crack, or warp under the influence of
heat and flame without weakening the floor.
Another part of my Invention consists in constructing buildings without columns,
the floors being held from above by tension rods or vertical suspenders surrounded
and protected by fireproofing material, instead of being supported from below
upon columns; the tension rods with their fireproof jackets occupying no more
space than unprotected cast-iron columns.
Another part of my Invention relating to illuminating floors and roofs I de
with an ornamental under face consists in making such floors and roofs by a plan or
method, according to which the ceiling or under face is moulded by itself in situ,
and the floor is moulded by itself in slab or grating form, and then put upon the
ceiling, the two being connected together, the floor joist being imbedded and
concealed within the construction between the two layers.
Another part of my Invention relates to making the windows of buildings fireproof
by means of illuminating fireproof shutters, and consists in furnishing the walls of
buildings with permanent reflecting fireproof blinds fixed in the window openings;
these slats may be twelve inches wide and six feet long, or more or less, according to
requirements; when open, they are to be set at an angle of about 45°, and are hinged or
swiveled to be closed at night; during the day they reflect the light from their interior
faces which are made to resemble daylight reflectors; a translucent top or lid is
provided to close the top or opening between the inclined surfaces; this lid is hinged
or made to be raised for ventilation, and to also swing inwards at night when the slats
are turned and brought to a vertical position to close the window. A modification of
this part of my Invention consists in making the slats of glass, fluted, corrugated,
indented, or otherwise, for both reflecting and transmitting light; in this arrangement
the shutters are an independent fixture, and may be of any kind in common use.
Another part of my Invention relating to fireproof constructions made of or by
means of Portland or equivalent cement, consists in adding to the cement or
locating within the concrete or cement body a volume or per-centage, say from two and
a half to ten per cent. of sulphur or equivalent material, the effect of which, when
the construction is subjected to great heat, is to impart a new quality to such
cement, viz., a power of resistance to cracking and falling away when the red-hot
mass is cooled suddenly by water thrown upon it.
Another part of my Invention relates to illuminating spaces and places under-
neath courts and passages of buildings, over which horses and carriages are com-
pelled to pass, and consists in making the glasses of the illuminating gratings used
over such places of a shape to admit of their being more perfectly protected than

page_text: "
the ordinary kind can be. The glasses hitherto employed for such purposes have
in general been circular in shape, and when of the diameter deemed best for
transmitting light, have caused the protecting knobs of metal between them to be
too wide apart to give the required protection, and my present improvement
consists in making oval lenses or glasses of elongated form, by which means while
retaining the desired area of light transmitting surface, I am enabled to bring the
knobs of iron near enough together to give perfect protection to the glasses.
Another part of my Invention consists in making illuminating concrete pavement
slabs with movable centers, as coal plates.
Another part of my Invention relates to open gratings, designed as guards, or fences,
and my improvement consists in cheapening such manufactures by making them of
metal combined with cement or concrete upon the general principles of construction
as herein-above explained with reference to beams and floors. Instead then of
using stout bars of iron expensively put together and liable to rust, I employ hoop or
other light iron in such lengths as may be required, in some cases bending the metal
in folds upon itself, and forming it thus into a variety of ornamental shapes threaded
upon wires or rods, or otherwise connected, which I then use as the metal core or
skeleton;
and having placed the same in a suitable mould to produce the external
finish or design required, I cast or otherwise form the cement or concrete upon,
within, and around the metal core. By this means I am enabled to make fences in
panels or otherwise, balustrades, guards, mullions, tracery, lattices, gates, and walking
and other open work surfaces, and generally all the varied architectural and
engineering forms and constructions now at great cost produced in naked iron,
including house fronts or walls.
In constructing fences or railings in this manner to enclose parks or other
grounds or spaces, a part of my Invention in some cases consists in casting or
making the sill, curb, coping, or foundation on which the fence rests along with the
fence itself, such fences or railings being made of preference in panels of suitable
length to be conveniently handled and set in position. I also propose to inlay these
constructions with ornamenting materials set in the concrete.
I propose also as a part of my Invention to make cement and concrete window
sashes in the manner substantially as herein-above set forth, the same being formed
with rebates or seats for the window panes; also in some cases I propose to cast
both mullions and sashes together in one piece, including in some cases the window
frame itself.
Still applying the tensile strength of metal as a core or skeleton within a body of
cement or concrete, another part of my Invention consists in making the roof of a
building a part of the walls as it were, bent over from opposite sides and meeting
at the center, the metal and concrete starting like a tree from roots or a foundation
interlaced with the ground, thence rising up into walls formed of columns and
blended tracery between the columns, until like branches bending over from opposite
sides, both columns and tracery interlock and form a roof. In this form I propose
to apply metal skeletons and concrete for making conservatories, railway stations,
churches, and other enclosing structures; the spaces of the tracery being closed with
light thin material, either glass or other material.
Another part of my Invention relating to the application of metal cores in com-
bination with cement or concrete, according to the methods and principles sub-
stantially as herein-above set forth, consists in making stairways and stoops of the
same, both illuminating and non-illuminating, and the members thereof, such as sills,
risers, treads, string pieces and platforms, and either separately or combined, the
same in whole or in part being in some cases applied to the making of illuminating
basement extensions in lieu of the ordinary illuminating gratings at present
employed for such purposes.
Another part of my Invention relates to the ventilation of buildings and to
chimney draughts, and consists, as to the former, in using and applying ventilating
panes to the sashes of the windows, which panes are made or furnished with pipes
or tubes, and valves for opening and closing the same, a part of the Invention

page_text: consisting in the manufacture of glass panes formed with an orifice open to the
external air when the pane is in position, such orifice terminating in a bent tube
opening upwards towards the ceiling of the apartment ventilated and lighted
thereby, the tube being of glass and making part of and one with the pane. As to
the latter or chimney draughts, my Invention consists in the use and application of
perforated zinc or other perforated metal or material to the making of chimney
tops or caps, the orifices or perforations of such metal or material being of sufficient size
to not readily clog up, and to also give free vent to the smoke in its passage to the
outer air, and at the same time being too small to allow currents of air or winds to
blow through them into the chimney sufficiently to interfere with its draught. The
form of the chimney tops or caps made from such perforated metal or material may
be varied to suit the caprice or fancy of those using or making the same.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Thaddeus Hyatt in the Great Seal Patent Office on the 4th December
1877.
THADDEUS HYATT, of 66, Gloucester Gardens, Hyde Park, London, in the County
of Middlesex, Inventor. "IMPROVEMENTS IN ARCHITECTURAL AND ENGINEERING
CONSTRUCTIONS AND MATERIALS, AND IN MEANS, MODES, AND PROCESSES CON-
NECTED THEREWITH.
"
My Invention relates to improvements in bridge, beam, and building constructions,
chiefly with respect to economy of metal, by the use of hydraulic cement or concrete
as a strengthener of the metal, and a substitute for that portion of it designed in
ordinary structures to resist compression.
My Invention also relates to means, modes, and processes of construction to
render buildings safe against fire, and to improve methods for lighting and
ventilating the same, and improving the draught of chimnies.
My Invention also relates to a new and cheaper method of making open gratings
for walking surfaces, and for guards, fences, railings, and similar purposes.
My Invention also relates to a new method of constructing buildings of metal
and concrete, the metal producing and distributing tensional or fibrous strength
and coherence throughout the mass, so that the roof, instead of being a load or
weight on the walls, becomes one with them. Also to making illuminating concrete
pavement slabs, with movable centres for coal-hole plates.
Bridge Constructions.-According to one part of my Invention my improvement
consists in the use and application of cement or concrete to the metal of bridges as a
crust or overlayer to protect it against rust and the influence of the sun's rays, the
same being applied by means of moulds or otherwise, and also in some cases as a
fireproof addition. For the most part, however, I propose to combine the concrete
with the metal as a means of cheapening such constructions, less mechanical skill
and labor being required to construct bridges of this character than those made
wholly of metal, the cement itself or concrete uniting the metal parts of the
bridge construction in a far more effectual manner than any mere reviting, and with
it in combination making a perfect structure.
Figures 1; and 1a, Figures 2, 2a, and 26, and Figures 3 and 3a on Sheet one
:

page_text: "
represent side elevations and cross sections of the bridge constructions herein
described. A and B, Fig. 1, represent top and bottom flanges of metal made in
'gridiron" form, that is to say, made of plates or bars of metal placed edgewise at
short distances apart, and threaded upon rods after the manner of my patented
gridiron beams. At proper distances apart the vertical metal ties or braces C, C,
connect A with B, the whole being encased, imbedded, and shut up within the
concrete mass D, D, which forms a perfect web between A and B.
Figures 2 and 2a represent a construction where the concrete is made to serve as
the compressive member of the construction in combination with the tie metal B.
Fig. 2b is a modification of 2a, the construction being formed with cells to lighten it.
Figures 3 and 3a represent a metal skeleton bridge made of angle iron at top
and bottom to form top and bottom flange, and connected by vertical metal ties or
braces, the whole being then imbedded within concrete, as shewn. One of the
advantages of this method of constructing bridges is that a light metal skeleton or
core may be made, easily handled and put in place, which skeleton may then be
conveniently and easily overlaid with the concrete to give rigidity and solidity to
the structure.
Gridiron-Tie Beams.-These beams are made by threading any convenient num-
ber of metal bars or blades upon wires or rods, the blades being formed with suitable
holes for the purpose, and placed edgewise, when the wires or rods, the blades being
formed with suitable holes for the purpose, and placed edgewise, when the wires or
rods or rods are passed through the holes, three or more ranges of thimbles being em-
ployed to each beam to hold the blades at proper distances apart. The wires that pass
through the thimbles are made with screw threads and nuts to tighten up the pack of
blades. Figures 4, 4a, and 4b, on Sheet one, represent this construction; d represents
the metal blades; e, the wires or rods; and i, the thimbles. Fig. 4a is a cross
section of Fig. 4, the plan; and Fig. 4b represents one of the blades. This form of
construction combines and concentrates, in convenient shape for handling, the tie
metals necessary for making cheap concrete floors, putting them (the metals) into
merchantable condition for use, sale, and transportation, and thus encouraging the
making of fireproof houses.
Tie Metal With the same object in view, that is to say, to encourage and
stimulate the building of fireproof houses, I manufacture metal ties of hoop iron or
similar material that may be used in single pieces and laid in between courses of
tiles or bricks, or into a bed of concrete, as the tie of the construction, and that will
not be liable to slide or slip when the beam or floor is under strain, the Invention
consisting in forming the metal with stops as represented by Figures 5 and 5a, where
m represents the hoop iron or flat tie, and o represents spurs or stops made of cut
wires about two inches long, more or less; these wires are driven into holes made
in the flat metal and project through on either side, so that when the tie is in
Another
place it cannot slip or slide when once the cement has set and hardened.
mode of making these ties is shewn on Sheet four, and indicated by the letters
X, Y, Z. Such tie metals may be made by cross-corrugating the hoop iron, as
shewn, or the metal when made may be rolled with cross ridges or projections, or
otherwise roughened to produce this effect. Z represents two ties placed one against
the other.
Another part of my Invention consists in making fireproof floors in two separate
layers or horizontal sections, or double floors, with an air space between the two for
greater security in case of fire. Figures 6 and 6a on Sheet one represent this
method of construction. Fig. 6 represents a concrete floor of gridiron-tie con-
struction in cross section of the metal; 6a represents the same, taken lengthwise,
or with the ties, r being the upper floor or walking surface; 8, the air-space; and
t, the lower floor or ceiling construction.
Another part of my Invention relating to buildings where the floors are of such
a span as to require columns for support, consists in the use and application of
suspenders or vertical ties from above in place of columns underneath, thus substi-
tuting wrought metal, steel for example, in place of cast iron, and in this way so

page_text: reducing the diameters of the supports as to admit of an encasement of fireproof
concrete or material within the limits of the diameter of ordinary cast-iron columns.
Figures 1 and 1a, and 16, Sheet 2, represent this Invention. In Fig. 1 the two
lower stories, A, B, shew the floors supported by cast-iron columns that are pro-
tected by fireproof jackets, while the floors of the stories D, E, and F are supported
by the vertical tie rod a; this tie rod, though protected by a fireproof jacket equally
as thick as the one surrounding the cast-iron columns, is of less diameter rather than
the naked cast iron. This mode of construction also shews how one storey of a mill
or other building may be made without columns or obstructions of any kind, the
story C being perfectly unobstructed.
Another part of my Invention relates to making the windows of buildings fire-
proof by means of illuminating fireproof shutters, and consists in furnishing the walls
of buildings with permanent reflecting fireproof blinds fixed in the window
openings; these slats may be twelve inches wide and six feet long, or less or more,
according to circumstances; when the whole of them are closed they form a fireproof
shutter, and when they are open they form, in combination with the glass lid, the
medium for transmitting light.
Figs. 2 and 2a represent the Invention; c, the fireproof slats or blinds formed
with a reflecting interior face similar to "daylight reflectors;" and d, a clear trans-
parent glass lid, arranged to lie upon the opened slat so as to keep out the weather
and admit light. The outside of the blinds or slats are also of preference made
reflecting to increase the number of light rays thrown into the chamber. e, f, g,
shew the arrangement of levers for opening and closing the shutters; but I make
no account of this part of the Invention, as many simple ways of doing this may
be easily devised; the essence of the Invention lies in the new kind of window
described, whereby light, ventilation, and fireproof protection are all combined
within a small compass at a comparatively cheap rate.
Fig. 2a represents the shutters as they appear when closed. By a modification
of my Invention I sometimes make the slats c of fluted, indented, or corrugated
glass, in which case besides reflecting they also transmit light. Under such circum-
stances the shutters are independent fixtures, and may be of the ordinary kind.
Another part of my Invention consists in combining bent metal with concrete in
a way which makes the roof to a degree self-supporting, and a part of the walls of
the building, as though the walls were somewhat elastic and bent over to form the
roof, the ranges or layers of metal being put together somewhat on the principle of
eliptical springs made of steel plates or leaves. This Invention is illustrated by
Figure 1, Sheet 4, and by Figures 3 and 3a on Sheet 2. Fig. 1, on Sheet 4,
may be regarded as representing an arched roof, or a section of a dome like the one
shewn on Sheet 2; the latter Figures represent the metal skeleton only, the one on
Sheet 4 represents the metals buried up in the concrete, which is indicated by
shaded lines. The design of this method of combining concrete and light metals is
to produce light and strong structures of concrete by reason of the metal fibres
interspersed throughout the mass in a manner somewhat analagous to the method
of nature in forming reeds and trees, the metals in my concrete buildings taking
their hold in the foundations as the roots of trees have their hold in the earth, and
passing upwards divide and branch, leaving openings for windows, and also in part
carried across such openings in finer filaments to form parts of the window as
illustrated by Figure 1, on Sheet 3, such a method of construction being particularly
applicable for purposes such as aquariums, conservatories, railway stations, and
other large enclosing structures composed mainly of walls and roofs.
Another part of my Invention relates to making stoops, steps, sills, risers, treads,
and flights of steps of concrete strengthened by a metallic internal framework or
core, and in some cases made illuminating by being set with glass, substantially in
the manner of making the stone lights or illuminating pavement slabs or gratings
of concrete and metal as made by ine for the footways of streets to form safe walking
surfaces. In making stairways or flights of steps, the "strings" may either be
separate pieces, and independent of the concrete construction, or be made a part of

page_text: it, this latter method constituting a part of my Invention, as less metal is required
and it is better protected against fire. In this connection a part of my Invention
consists in applying the concrete constructions aforesaid to the making of
basement extensions as a substitute for the iron and glass now employed for such
purposes.
Figures 4 and 4a on Sheet 2, and Figure 2 on Sheet 4, represent this part of my
Invention.
Fig. 2, Sheet 4, represents a flight of concrete steps, the shaded portions being
concrete, moulded upon gridiron tie-metal coves as shewn. These steps are moulded
after the pattern of ordinary stone steps, and are designed to be employed in the
same manner, and let into the walls of the building in the same way.
Figure 4a, on Sheet 2, is a plan, and 4, a cross-section of steps moulded to repre-
sent a tread and a riser, the gridiron tie metal being placed in the tread. This is
the preferable shape when the steps are required to be set with glass, as both riser
and tread may then be made to transmit light.
Another part of my Invention consists in making the glasses employed in the
manufacture of "illuminating gratings," of an elongated, as opposed to or constrasted
with circular and square-shaped glasses, such as are commonly used, and in making
the lenses upon such glasses of an oval or elongated form in place of the circular
form usually employed, the object of this change of shape being to bring the pro-
tecting knobs or protuberances of iron between the glasses nearer together than can
be done where the glasses are of the ordinary shape; by this means a more per-
fectly protecting surface of metal is formed between the glasses to preserve them
from injury, and a better walking surface is also made; and especially and
principally, a style of illuminating grating is thereby made, that is, adapted
for use in court ways and other places over which horses and carriages
are compelled to pass, and beneath which light is at the same time required.
This Invention is illustrated by Figures 3 and 3a, on Sheet 4, and by Figures 2
and 2a, on Sheet 3, the latter representing elongated glasses with the corners taken
off, thus exhibiting one method of arranging and locating the protecting buttons or
knobs of metal; and the Figures on Sheet 4, representing in full size a more perfect
form, or one furnishing the greatest amount or per-centage of light together with the
best walking and protecting surface of metal. A, A, are the glasses, one inch and
five-eighths long, by seven-eighths of an inch wide, 3a being a cross section on the
line x, x, and shewing the rise of the oval lens glasses; B, B, are the knobs or pro-
tecting metal buttons; and C, C, is the main body of the iron grating. The oval
line upon the glass represents the shape of the lens face upon the glass, the rise of the
lens being shewn on 3 as already said.
Another part of my Invention consists in making illuminating concrete pavement
slabs with moveable centres as coal plates. This part of my Invention is illustrated
by Figures 3 and 3a, on Sheet 3. A, A, is the illuminating concrete pavement slab
or grating, the shaded portions in the cross section 3a representing the concrete
portion of the construction, and a, a, representing the glasses. The opening or
central hole which is filled by the coal plate B, has its edge protected by a metal
frame, seen at c, c, in 3a. This metal frame is cast with radiating armes or blades
e, e, to hold the concrete, and give greater strength to the construction, additional
blades or rods of metal between the ranges of glasses being also employed
when necessary or desired. The coal plate B is a concrete slab set with glasses to
give light, and moulded upon a gridiron metal construction as shewn, the concrete
being moulded or cast within an enclosing and protecting metal band d, d, Fig. 3a,
as shewn.
Another part of my Invention relates to open gratings designed to serve as
guards or fences, and my improvement consists in cheapening such manufactures by
making them of combined metal and cement or concrete, upon the general principles
of construction as herein-above set forth with reference to beams and floors. Iron
railings, gratings, and guards, as usually constructed, are expensive, because of the
amount of metal employed in such manufactures, and the labor required for the

page_text: same. By my improvement light blades or bars of metal are used that are merely
punched with suitable holes to pass the necessary wires through upon the plan of
the gridiron ties already explained, and then these are made use of as cores upon
which to mould the concrete, railings, gratings, and guards, as illustrated on
Sheet 3, by Figures 4, and 4a, and 4b, Figs. 5, and 5a, and 5b, Figs. 6 and Ga,
Figs. 7 and 7a, Figs. 8 and 8a, and by Figures 9 and 9a.
Figure 4 represents an open stone grating, of great strength, designed for being
walked upon, the blades of metal being numerous and placed near together; Figure 5
represents a lighter and cheaper one, the blades of metal being fewer and placed
wider apart; 4a is a cross section of 4, at x, x; and 46 represents one of the
blades, and shews where the cross wires pass through it; 5a is a cross section of 5
at x, x, and 56 represents one of the blades and shews where the cross-
wires pass through it. This method of construction is equally applicable
for guards and railings. Figures 6 to 9 represent railings and guards, the
shaded portions indicating the concrete, and the black and dotted lines the
metal.
A part of the Invention consists in making or casting a concrete coping at the
bottom of the construction or panel, when used as a guard or area railing or fence,
also in making open work or lattice doors or gates of concrete and iron, and
partitions or walls of buildings, the blades of metal being threaded upon suitable
wires or rods and overlaid in manner already described; and generally all the
varied architectural and engineering forms and constructions now at great cost
produced in naked iron that constantly decays unless kept painted, but when
made according to my improved method may last for ages.
A further part
of my Invention consists in ornamenting the before-described constructions by
means of tiles, glass, or other inlays let into or cast in with the concrete when
moulded into form upon the metal.
Another part of my Invention having reference to concrete or artificial stone or
brick beams moulded in sections or brick-form consists in forming such bricks with
indents or recesses on the sides thereof, so as to be readily attached to the tie or
skeleton of metal; in this way the skeleton or tie may be first placed in position,
and then the bricks be cemented together upon them with the effect of enclosing the
metal within the body of bricks; or the bricks may be formed with a projecting
top or sides to rest upon the tie, the body or a portion thereof descending or passing
below the ties, so that when the ranges of bricks are cemented together wedge-
shaped channels will be thereby formed underneath the metals, which channels are
subsequently made good by cement. D, D, Figure 4, Sheet 4, represents the bricks
made with indents or recesses in the sides thereof; and E, E, Figure 5, Sheet 4,
represents the bricks made with wedge-formed bottoms, as described.
Another part of my Invention connected with floors made of concrete or equiva-
lent material as the compressive member in combination with tie metal, consists in
making such constructions with the metal in excess of the compressive strength of
the structure; the object being to make a floor that shall give warning of danger
if unduly loaded, by bending before breaking.
Another part of my Invention connected with floors and roofs, and other con⚫
structions made of Portland cement, consists in a means of rendering such cement
and its concretes less liable to crack and fall to pieces, when, after being subjected
to great heat, it is suddenly cooled by water thrown upon it; my Invention con-
sisting in combining sulphur, or some substance containing sulphur, with the cement
or concrete, of which the floor or roof is made, which, although adding nothing
valuable to the cement so long as it is not exposed to fire, has the power when the
cement is subjected to heat of imparting to it a new quality or toughness, in virtue
of which it is capable of withstanding fire and water, as it otherwise would not, the
Invention consisting in locating within the body of a concrete floor or other structure
a chemical substance inert until the breaking out of fire, and then protecting the
construction against fire by the very action of the fire itself upon it, not to repel

page_text: the fire or put it out, but to strengthen or toughen the concrete or body within
which it is located.
Another part of my Invention consists in the use and application of perforated
metal to the making of chimney caps for promoting the draught of chimnies, these
caps of preference being made of the full size of the chimney at top, and in the
nature of an architectural finish thereto; the size of the perforations being such as
to freely admit the exit of smoke, while the general body of the metal offers
sufficient obstruction to winds to prevent them from interfering with the draught of
the chimney; a part of the Invention in some cases consisting in making
the cap double, the orifices of the outer cap breaking joints with those of the
inner one.
THADDEUS HYATT. (L.S.)