AN IMPROVED MODE OF FIREPROOF BUILDING
Year: 1884

page_text: I, EDWARD LACY GARBETT, of 3 Myddelton Square, Clerkenwell, in the County
of Middlesex Draughtsman do hereby declare the nature of my Invention for -
AN IMPROVED MODE OF FIREPROOF BUILDING" to be as follows:-
"
My Invention is for constructing Stairs, Floors or Roofs by combining certain
forms of earthen Tubes or tubular Bricks with Ties of rolled Metal, and sometimes
with small portions of other Materials, but so that the Stability depends only on
the said Tubes' or Bricks' resistance to crushing and on the Tenacity of the Ties.
The Tubes or tubular Bricks, (hereinafter for brevity called Tubes whether having
but one Bore or several) run in Courses crossing the Line of Tie, and whether the
said Courses be all similar or of two forms alternately, their Sides that meet have
S-like Profiles, so fitting together that each piece can only be slid lengthwise into
its place between the two adjacent Courses. They have sections varying according
as they are to construct Stairs, a Floor or Terrace, a gabled Roof, or a hipped Roof.
For a straight Flight of Stairs I use two forms whose Contours resemble A and B
in Figure 1; but their Bores vary in number and shapes for different qualities of
Clay. Each Course of A makes the inner half of a Tread and lower half of a
Riser, but each Course of B the upper half of a Riser and outer half of a Tread.
A board perforated so as to admit a row of the A Tubes, will hold them in due
relative Positions while half their Lengths are being built into the Wall. Their
halves that project are then ready to clasp between every two of them a B Tube.
The halves of these then project so as to hold similarly a second row of A Tubes,
and these a second row of the B sort, and so on till the Stairs reach their intended
Length from the Wall. Their lowest and highest Courses are stiffened by Bars
through their lower Bores, and a flat metal Tie-band, applied under the Flight, will
pass through and be keyed beyond two Plates or Holdfasts inserted in the Beds
below and above the said extreme Courses of the Flight.
For the second Application of this Invention, namely to Landings or Floors, three
forms of Tube are required, one to form a Beam across the Width, and two to run
lengthwise in alternate Courses, one of which penetrates, but the other is stopt by
the Beam, so that I call them the Through-tube and Blind-tube. Each piece of
Beam-tube, as it descended from the Mould, had one or both of its upper Corners
bitten out to a hollow shape fitting half the Profile of a Through-tube; so that
when two such Beam-pieces form part in a Beam, they can clasp between their
Heads the middle of a Through-tube. The projecting ends of the Tubes thus held
D

page_text: will then receive and hold between every two of them a Blind-tube; the projecting
halves of which will similarly hold a second row of the Through-tubes, and these a
second row of the Blind, and so on till arriving at the place intended for another
Beam. Thus a Floor, begun by the Beam nearest its Centre, is extended each Way
till complete.
Instead of a Beam thus composed of Pieces all similar, I may prefer, in most
cases, its middle and longest portion to be of shallower and lighter Tubes, but a few
toward each Wall to be of gradually increased Depths, as in Figure 2, and the Tie
threaded only through the deepest ones, as there shown.
The upper Faces of all the Tubes are level, to form the Floor; but over inhabited
Rooms their Undersides are so formed as to present no level Face, any such in a
Ceiling being harmful, but to guide all rising Air through Holes into the Through-
tubes, which convey it into the larger Bore of one of the Beams, and this into an
ascending Flue in the Chimney.
Under a Terrace, this Structure will be made to camber in two Planes up to a
Ridge, as in Fig. 3, by having all the Pieces in a Beam similar except four deep and
tapered ones, the two at the Bearings turned with their narrow End upward, and
the two at the Middle with it downward enclosing a Stirrup to suspend the Tie.
The Invention is equally applicable to all gabled Roofs and the Trusses bearing
them, by making the Truss contain an Arch, whose two Springers or Skewbacks
are confined by a metal Tie. This Arch is to be composed of short tubular Bricks
of two or more forms alternating, lying horizontally across its width, but the
Spandril-filling above it, and also the Body of the Roof, of the largest of these
Tubes alone, in courses parallel to the outer Slopes. In the Body of the Roofing
these will be alternately reversed, and each alternate Course be interrupted at
certain Levels by a Course of a Kind resembling Beam-tubes but smaller, forming a
Purlin when the Row of them from one Truss to another has a Tie threaded
through their lower Bore and keyed.
The Principle will be yet more simply applied to hipped Roofs, or rather to a new
or disused Form thereof which I regard as the best of all Modes of roofing a
Rectangle, namely in Eight Planes, rising at equal inclinations from the Slopes of
four equally inclined Gables or Pediments on all the Walls. As the gutters of such
a Roof conduct all its Water to the Corners, I shall further claim to modify the
corner Wall-bricks in such ways as to dispense with Fraginents called Closers, and
at the same Time either form a descending Rain-duct through themselves, or present
Claws to attach and uphold earthen Rain-pipes.
Dated this first day of January 1884

page_text: I EDWARD LACY GARBETT, of Number 3, Myddelton Square, in the Parish of
Clerkenwell, and County of Middlesex, Draughtsman, do hereby declare the nature
of my Invention for AN IMPROVED MODE OF FIREPROOF BUILDING, and in what
manner the same is to be performed, to be particularly described and ascertained
in and by the following statement:—.
This Invention consists in constructing either straight Flights of Stairs, Floors,
Landings, Terrace roofs, gabled Roofs or hipped Roofs, by combining earthen
Tubes or tubular Bricks of several new Forms with flat rolled metal Ties, in such
Ways that the Structure can fail only by a direct pulling asunder of the Ties, or
crushing of the Bricks. As there is no Dependence on other Material than these
two, nor on any other Property in the Metal than its Tenacity, much of which is
retained by Iron at even a red Heat, such Structures will be far less destructible
by Fire than those commonly now called fireproof, which use the Stiffness of their
Iron, and extravagant Quantities.
For Stairs (but only for a straight Flight or the straight Part of a Flight) two
Forms of tubular Ware will suffice; the shallow having a Section like A, producing
the inner Half of a Tread and lower Half of a Riser, while the deep Form B gives
Where the Clay is inferior,
the upper Half of a Riser and outer Half of a Tread.
the Bores should be smaller but more numerous, and where it is very good they
Their Length also depends on the
may be as few and large as in A¹ and B¹.
Quality of Clay, as any should be rejected that warp above 1 Inch from
Straightness, at their Middle. Fig. 6 is a Board, (all objects not earthen being
here marked with small Letters, but earthen Tubes with Capitals) and this Board,
being perforated, admits a Series of A-tubes half through it, to hold them in due
relative Positions while being built into a Wall by half their Length; but
afterward serves as Skirting. The projecting Halves of these A will then, at any
The Halves of
Time, receive and hold, between every adjacent Pair, a B-tube.
these latter, then protruding, will similarly hold a second Row of A-tubes, and
these a second Row of B, and so on till the Stairs reach out their intended Length
from the Wall. The Courses that are then short, (which will preferably be A.)
will be finished by half-length Tubes, or rather by some exceeding half the general
Length of others by an Inch or less, that this Excess may enter Mortices in the
outer Stringboard that is to bear the Balusters. The extremne Courses, beginning
and ending a Flight, will be kept rigid by a Bar through their widest Bore, preferably
of Slate; and the two Beds above the upper, and below the lower of these Courses,
will receive the bent Holdfasts h, h, to whose flat Portions the Tie-bart will be
keyed by the Wedges k, l, entering two of the vertical Joints.
A sufficient Weight for the Tie or Ties of a Flight will be as many lbs per
square Yard of horizontal Plan, as the Flight contains Steps.
A Flight isolated from any Wall can be constructed by placing first the Board b
centrally, completing the Stairs from it both right and left, and then cutting b
away.
A B' are Sections that Stair-tubes may have, when used for Flights a few
Degrees less steep than the Inclination that makes their Treads level; they being
5 levelled up by Cement, which the Grooves g g g will tend to retain in its Place.
A2 is a Profile for A that will admit of fastening a Stair-carpet, by a wooden or
metal Bar in the Place of the usual Rods.
The Second Application of my Method is to Landings, Floors or Terrace-roofs,
and requires three Forms of Tube; as D, which I name the Through-tube because

page_text: each Course thereof extends through a Floor from End to End; E, which is to
alternate with D, but be stopped by every Beam, whence I term it the Blind-tube,
and F the Beam-tube. A course of these F, having a Tie threaded through their
lower Bore, and keyed at the Ends, would form a Beam; but each Piece of F, in
descending from the Press or moulding Machine, has had one or both of its upper
Corners bitten away by a transversely moved Cutter, leaving a Recess that fits
half the Profile of a D-tube; so that each Pair of F or Beam-tubes can clasp
between their Shoulders the Middle of a D-tube crosswise, as seen in Plan N° 1.
The Length of Beam between one D and the next may be in one Piece, whose
upper Corners are both removed, or in two, as here shown, each retaining one
upper Corner entire; these being provisionally held together by Pegs. The whole
first Beam may be constructed below, and lifted to its Place, spanning the Room
at or near its Mid-length. Each Pair of the Ends of its D-tubes will then receive
and hold half the Length of an E-tube. The projecting Halves of these will in
like manner clasp and hold another Row of D; which will similarly take another
of E, and so on, each way from the first Beam, till a Row of D have crossed the
Place designed for the next Beam, which will then be formed by hanging F-tubes
between these D, threading a Tie through its lower Bore, and keying the Ends.
Those D-tubes that cross a Beam exceed the Length of their Fellows, and of all
E-tubes, by the Width of the Beam-tube F. When the Number of E to extend
between Beam and Beam exceeds two, the outer Course of them, on each Wall,
should be stiffened by a Bar, preferably of Slate, through their wide Bore.
Though this Construction of Floor, with only D, E and F, needs but those three
Patterns of Tube, quite encloses the Ties, and gives a Cieling with no Lodgment
for Dust, yet I would, for most Purposes, forego these Advantages for greater real
and apparent Lightness; by substituting for nearly all the F-pieces, except those
on or near the Walls, the shallower and much lighter Beam-tube C; leaving most
of the Tie exposed, as in Provisional Specification, Fig. 2; its Ends only being
threaded through the deepest F Terminals, one or two next each Wall, (and those
on the Wall). Moreover, for Spans exceeding a few Feet, successively deeper
F-pieces, as F F and more, should be used, and the Tie pass through only the
deepest sort; as the lower it can be placed, the less Iron does it need. The same
Action that bites away upper Corners from these F' F' &c, should also remove one
lower Corner, to give it a bracket-like Profile. A Pair of the deepest Terminals
may sometimes, in the Middle, serve to enclose a Stirrup suspending the Tie to
perfect Straightness; but not to raise or camber it, as this would make the Ceiling
above appear to sag. Fig. 3 of my Provisional Specification gives the Arrangement
for a Terrace-roof.
It will be observed that C, D and E have no flat or level Undersides. They are
designed to have none, because the Properties of Airs, known for above a Century,
have shown it to be a primary Duty of Ceilings to lead away without Delay the
respired or warm Air that rises to them; but by any level Surface of Ceiling it is,
on the Contrary spread out, cooled, sent back and mixed, as thoroughly as possible
with all the Air below; so that nothing can be more anti-sanitary than every level
Ceiling or Portion of a Ceiling; even were the upward Drainage of respired Air 4
freely provided for by outlets at the very Ceiling-plane itself, which is very
infrequent. To provide then for free natural Outflow, my Tubes E, forming the
greater Part of the Ceiling, are shaped to cut ascending Currents, and lead them
immediately to the Air-holes a a, perforated in the Sides of every D-tube, at
Intervals of but a few Inches; those on one side of the D-tube being opposite the 5
Solids of the other Side. Now by leaving both Ends of each Course of D open to
the Exterior, we should, in Climates where Rooms are never artificially warmed,
accomplish our End. But here that we use Chimneys, it is not to be done so
simply, for the Draught of a Fire, whenever lighted, would at once reverse this
Action, and suck a Supply through these intended Outlets. As the Chimney then 5
becomes the only possible Outlet, as well for foul Breath as for Smoke, it becomes
necessary to stop the Ends of the D-courses and give them Outflow to the Smoke-

page_text: flue itself, if there be no special Foul-air-flue built in each Stack. Such a Flue,
besides those for the Fire-places, ought to be provided in each Stack; and in
Cities, Builders will have to be compelled by Law to provide one, beginning below
the ground Ceiling, and carried up as high as the adjoining Smoke-dues. But in
any Case, I provide for each Course of D conveying its foul Air into one of the
Beams that it crosses, and this Beam can be arranged to convey all the Outflow
of the Room into the ascending Flue, because whether the Chimney be in a Side,
an End or a Corner of the Room, one Beam can be so placed as to enter it. The
upper large Bore of every Beam-tube C, F, F1, F &c, would provide the required
Duct, but those Lengths of D-tube that cross the said Outflow-beam must have
a central downward Vent or Perforation, nearly as large as their own Bore. The
D-pieces crossing other Beams will have no downward Perforation. Only over
uninhabited Passages and over Warehouses ought imperforate D-tubes, or a
cheaper Pattern of E than is here shown, to be allowed.
The third Application is to gabled Roofs, and the Trusses bearing them; and
the Patterns of Tube will be but one in the Body of roofing, as G, while the
Trusses to bear it will be chiefly of the same G, but combined with some others, at
least two, H and I. To form such a truss-like Support, the Tie-bar of flat Iron f.
placed on Edge, will have each End clasped between a Pair of the Springers or
Skewbacks S S, of Stone, Brick or cast Metal, and keyed beyond them. From.
these an Arch is to spring, composed of two or all of the Forms of Tube G, H, I,
variously alternated. These have their Patterns so made in Relation to each other
that G alone, alternately inverted, would give a straight Course, G and H
alternating make a Curve of large Radius, G and I give one of about half that
Radius, H alone a sharper Curvature, H and I alternately a still sharper, and
finally, I used alone, a sharper than any of these four. Not only then may any
moderate Span be arched by a Segment, of one of the five Curvatures, but
Combinations of two or more of these five, in the same Arch will enable, any
non-circular Curve yet used in Building to be closely imitated; and under
any proposed Roof, not of a low pediment Pitch, it will be best to use some
compound Arch; the flattest Curves being used at the Feet, and the sharpest at
the Crown of the Arch. All these Tubes are to lie horizontally, crossing the Soffite
or Back of the Arch; but the Spandril above will be filled with G-tubes alone, which
may, for that Purpose and for the Roof-body, be made longer than those used in
the Arch, that they may all run in Courses parallel to the outer Slopes. Those
in the Spanril will all have their Convexities downward, and the first Piece for
each Course be readily cut to fit roughly the Arch-back; and most of these can but
against the prominent Tops of H', a Modification of H made with that View. In
the Body of the Roof, the G-tubes will have their Convexities alternately turned
upward and downward, as seen in the Section No 2, through a Portion of a Spandril
and superincumbent Roof-body, built with another Pattern of G, somewhat wider
and shallower. Each alternate Course in the Roof-body will begin with a half
length G-tube, and all will start from a Pole-plate p, of angle or T Iron, bearing
on the Springer-blocks S. Those Courses of G in the Roof-body that have their
Convexities upward will, at a certain Level, be interrupted by a Pair of the Tubes J,
which have, in their Manufacture, been treated like the Floor-beam-tubes C, F, &c,
one upper Corner being bitten away to leave a Recess that fits a Part (not half) of
the Profile of a G-tube; and thus a Row of Pairs of these J, but not a continuous
Course, will extend from Truss to Truss, or even the whole Length of the Roof, and
having a Tie threaded through their lower Bore, will form a Purlin. The Top
of each G-tube in the Roof-body will afford a Hold for the fastenings of the
Covering.
The fourth Application is to hipped Roofs, or rather to a new or disused Form
of Roof that I would prefer, in eight Planes, meeting at eight Hip-lines. If the
Plan were square and the Pitch high, it would resemble German Church-spires,
but I know of no Example moderately pitched, nor on an oblong Plan. However
oblong it may be, the four Hips that rise from the Corners are of one Length, and

page_text: the four others are of one Length, shorter than the former, in the ratio of 1 to ✓ 2.
All the four Walls must have Gables or Pediments, the Tangent of whose
Inclination is to that of the Inclination of the Roof planes as 13 to 34, very nearly.
A chain-tie must be formed to confine the Feet of the Roof-tubes, which will all
run in Courses parallel to the nearest long Hip. They may be of a Section
resembling the H-tube, but I prefer one like K. Each long Hip requires one
like L, and whose Profile depends on the Pitch. The four Junctions of the Chain-
tie at the Heads of the Gables, will be by Plates which will be restrained by two
flat Tie-bars, each connecting the Heads of two opposite Walls. The shorter or
upper of these Ties should be straight, but the longer one have its Middle raised to
meet it, and both suspended by a Bolt from the central Cap.
As this Forin of Roof, with earthen Gutters, will collect all Water to the
Corners, I would build them with a Variety of Wall-bricks having a Recess on
the Angle, as M, to accommodate earthen Rain-pipes; and some of them formed
either like O, to embrace each Length of such Pipe, or like N, with a Claw, two
of which in two successive Courses will have a similar Effect of upholding a Length
of Pipe.
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
:
First The constructing either Flights of Stairs (on a Straight Plan) Floors or
Roofs, by Courses of earthen Tubes, crossing the Direction of metal Tics,
and the Sides of which courses have S-like Profiles, so fitting that each
Tube has generally to be slid lengthwise into its Place.
Secondly: Making a Beam of a Course of Tubes or tubular Bricks, crossing the
above-said Courses, and having the upper Corners of its Pieces cut outto
fit the Profiles of some of those Courses.
Thirdly: Making three or four Forms of tubular Bricks with S-like Sides, so
combinable that they make Arcs of five or more different Radii.
Fourthly. Constructing the Planes of a hipped or pyramidal Roof, whether eight
or more or fewer, by Courses of Tubes or tubular Bricks running in the
Directions of some or all of the Hips, and restrained at their Feet by an
enclosing Chain-tie.
Fifthly. Wall-bricks for Corners, made the Length of those in the Body of the
Wall, and once and a half their Breadth, and recessed on the Corner to
accommodate earthen Rain-pipes, and having Claws to embrace and hold the
said Pipes.
Dated this twenty-ninth day of September 1884