A NEW SYSTEM.OF. METALLIC ARCH, PROPER FOR THE CONSTRUCTION, OF BRIDGES, ARCADES, VAULTS, Roors, AND ALL OTHER SUCH PURPOSES.
Year: 1855

page_text: LETTERS PATENT to Georges Antoine. Tabourin, of Lyon's, in the Empire
of France, Student, for the Invention of: "A NEW SYSTEM.OF. METALLIC
ARCH, PROPER FOR THE CONSTRUCTION, OF BRIDGES, ARCADES, VAULTS, Roors,
AND ALL OTHER SUCH PURPOSES.".

page_text: stiff beam or arch, consisting of several jointed fractional arches. The end
arches are jointed to the lugs D, which project on the face of a jutting plate B,
which is cramped in the stone work.
Fig. 1 shows two arches A, A', jointed together in a¹, one of which A is
jointed with the jutting plate B; Fig. 2 is [a front view of the plate B, and 5
Fig. 1 is a side view of the same.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said George Antoine Tabourin in the Great Seal Patent Office
on the 4th January 1856.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, GEORGE
ANTOINE TABOURIN, of Lyons, in the Empire of France, Student, &c., send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Fourth day of July, in the year of our Lord One
thousand eight hundred and fifty-five, in the nineteenth year of Her reign,
did, for Herself, Her heirs and successors, give and grant unto me, the said
George Antoine Tabourin, Her special license that I, the said George Antoine
Tabourin, my executors, administrators, and assigns, or such others as I, the
said George Antoine Tabourin, my executors, administrators, and assigns,
should at any time agree with, and no others, from time to time and at all
times thereafter during the term therein expressed, should and lawfully might
make, use, exercise, and vend, within the United Kingdom of Great Britain
and Ireland, the Channel Islands, and Isle of Man, an Invention for "A
NEW SYSTEM OF METALLIC ARCH, PROPER FOR THE CONSTRUCTION OF BRIDGES,
ARCADES, VAULTS, ROOFS, AND ALL OTHER SUCH PURPOSES," upon the condition
(amongst others) that I, the said George Antoine Tabourin, by an instrument
in writing under my hand and seal, should particularly describe and ascertain
the nature of the said Invention, and in what manner the same was to be
performed, and cause the same to be filed in the Great Seal Patent Office
within six calendar months next and immediately after the date of the said
Letters Patent.
NOW KNOW YE, that I, the said George Antoine Tabourin, do hereby
declare the nature of my said Invention, and in what manner the same is to
be performed, to be particularly described and ascertained in and by the
following statement:-
The fractional arches of my system are generally made of cast iron, united
together by under lugs, jointed together, somewhat like the head of a pair of

page_text: compasses, or the joint of a folding foot rule; a central joint bolt is passed
through the under lugs. Each beam or girder, forming a complete arch, is
composed of as many fractional arches as may be required to form the total
length of the whole beam or arch, the length of the said fractional beam or
arch having been previously determined. The beams or girders just mentioned
are laid up in parallel lines at a suitable distance from each other, so as to
form bridges, vaults, or arcades of the required breadth; they are then united
with each other by single bolts passing through the centre of the lugs, which
are separated by tubular transoms traversed by the same bolts. The lugs or
compasses heads forming the hinged joints of the arches are situated at the
lower end of each of the said arches, whilst the upper part of both their ends.
forms a plane or propping face, so disposed that the adjoining propping faces
of two successive arches may bear on each other, in order to transmit on the
butment the jutting out or force which would tend to bend the vault down.
The annexed Drawing represents a bridge of cast-iron arches according to
my plan.
Figure 1 is a front view, and Figure 2 a plan or horizontal projection of
the bridge, part of the floor of which has been taken away to shew the arches
and their tubular transoms. A, A, A, A, A", A", plan of beams, each of
which in this instance is composed of seven fractional arches of cast iron.
Figure 3 represents a view of one of these arches. a, lug or compasses head;
r, central hole for the joint bolt which unites two successive arches; r², r²,
holes for the passage of the fastening or stay bolts, which unite together all
the parallel arches; the latter are separated by tubular transoms B, traversed
by the bolts b, Figure 4, as already stated. Figure 4 is a plan of two of the
said parallel arches, with their transoms B, through which the fastening bolts b
are passing, which bolts are screwed on the external face of the first and last
arches by the screw nuts e; C, transom through which the joint bolt b¹ passes
so as to unite the lugs or compasses heads a; T, T, upper ends or propping
faces of the arches, the said propping faces of two adjoining arches leaning
or butting against each other; a thickness of any suitable compressible inate-
rial, such as lead, may be placed between the two faces, in order to secure a
close contact by the pressure resulting either from the weight or the dilatation
of the arches. D, butting end or foot plate. Figure 5 is a side view, and
Figure 6 front view of this plate. a, lugs corresponding to the compasses
heads of the arches, with which they are united by the joint bolt 6". The
arches of this system may be employed for building bridges, vaults, either by
using uniformily-shaped fractional arches, as in the annexed Drawing, in which
case they form a flattened elliptical arch or fractional arches higher near the

page_text: foot of the arch, so as to form an arch of a longer flitch. On the right side
of Figure 2 a portion of a floor made of thick boards laid across on the beams
is. represented. The said boards may be covered up with a layer of concrete
mortar and bitumen in order to preserve the wood, but I contemplate making
the 'floors of these bridges with cast-iron plates, striated on the upper face,
and with ribs underneath; which ribs, clamping the upper edges of the beams,
would act at the same time as stays or transoms, to maintain the distance of
the beams.
..One of the principles of the Invention is the hinge-like joint of two adjoin-
ing arches, which allows of the comparatively easy conveyance of the said
bridges, and of their being erected quickly and with great facility. The
repairs can also be made much more easily than is the case with either ordi-
nary suspension wire bridges, or with those made of stone or of cast iron.
If any of the fractional arches happened to be fractured, it would be easily
perceived, and the whole bridge-being bound together, the fracture of a frac
tional arch would not be attended with imminent peril, and as it might be
easily replaced, the repair would stop but for a short while the traffic of the
bridge.
>This system of jointed arches may also be employed in the construction
of buildings for the beams of roofs of great length, by merely modifying one of
the ends of the first and of the last fractional arches, which should then have
a propping face at the lower end, and also a resting face or footing, butting
and resting on the top of the wall. This arch should be modified, as seen in
Figure 7, which is a front view, and Figure 8 an end view. T¹ is the lower
butting face against the wall, and A the sole or footing which is resting on the
top of the wall..
In witness whereof, I, the said George Antoine Tabourin, have hereunto
set my hand and seal, this Twenty-ninth day of December, One
thousand eight hundred and fifty-five..
Signed and sealed in the presence
L. D'AUBREVILLE.
of
G. A. TABOURIN.
(L.S.)