CANADIAN OF RomeRS AND ARCHES
Year: 1865

page_text: LETTERS PATENT to Frederick Allen Leigh, of the City of Manchester,
in the County of Lancaster, Mechanical Engineer, for the Invention
Taman CANADIAN OF RomeRS AND ARCHES"
Sealed the 26th September 1865, and dated the 29th March 1865.
PROVISIONAL SPECIFICATION left by the said Frederick Allen Leigh at
the Office of the Commissioners of Patents, with his Petition, on the
29th March 1865.
I, FREDERICK ALLEN LEIGH, of the City of Manchester, in the County of
Lancaster, Mechanical Engineer, do hereby declare the nature of the said
Invention for "IMPROVEMENTS IN THE CONSTRUCTION OF BRIDGES AND ARCHES,"
to be as follows:-
This Invention consists principally in forming arches of hollow cast iron
pipes in lieu of the usual masonry, dispensing also with beams and girders, as
they are generally constructed. These pipes may be round, square, or wedge-
like, but I prefer the elliptic or egg-shape form, as better adapted to resist the
crushing pressure with less weight of material than any other. For bridges
I lay them transversely to the roadway, key or bolt them together, laying the
ballast, and building the parapet walls upon them, allowing the end pipes to
rest against the abutments. When used as girders for suspension bridges and.
other purposes, I cast the pipes in short lengths, span the chasm in the arch..
form with them, and suspend the roadway or support a roof or other object.
above or below, as the case may be.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Frederick Allen Leigh in the Great Seal Patent Office on the
29th September 1865.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, FREDERICK
ALLEN LEIGH, of the City of Manchester, in the County of Lancaster, Me-
chanical Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-ninth day of March, in the year of our Lord
One thousand eight hundred and sixty-five, in the twenty-eighth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me, the
said Frederick Allen Leigh, Her special license that I, the said Frederick Allen
Leigh, my executors, administrators, and assigns, or such others as I, the said
Frederick Allen Leigh, 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 "IMPROVEMENTS IN THE
CONSTRUCTION OF BRIDGES AND ARCHES," upon the condition (amongst others) that
I, the said Frederick Allen Leigh, my executors or administrators, by an instru-
ment in writing under my, or their, or one of their hands and seals, 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 Frederick Allen Leigh, do hereby declare
the nature of my said Invention, and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following
statement (that is to say):-
This Invention consists principally in forming arches of hollow cast-iron
pipes in lieu of the usual masonry, and dispensing with beams and girders, as
they are usually constructed. These pipes may be round, square, or wedge-
like, but I prefer the elliptic or egg-shaped form, as better adapted to resist
the crushing pressure with less weight of material than any other. For bridges
I lay the pipes transversely to the roadway, and key or bolt them together,
laying the ballast and building the parapet walls upon them, allowing the 'end
pipes to rest against the abutments. When used as girders for suspension
bridges and other purposes, I cast the pipes in short lengths, span the chasm

page_text: in the arch form, and suspend the roadway or support a roof or other object
above or below, as the case may be.
This Invention will be clearly understood by referring to the figures and
letters on the accompanying two Sheets of Drawings.
In Figs. 1, 2, and 3 I represent one mode of employing round cast-iron
pipes in the formation of an arch. The said pipes are shewn at a; they are
encircled by blocks or slippers of metal b, having their ends radiating to the
radial centre of the arch, the two end blocks abutting as at c, against the top
of the abutments d.
In Fig. 4 I represent two modes of employing the pipes as girders for
bridges. One mode is shewn from the abutment A to the centre line B, and
the second mode from the centre line B to the abutment C. In the first
mode the pipes are cast with thickened ends radiating to the radial centre of
the arch, and are used in the same manner as the stones of an arch of
masonry, and in the second mode the pipes e are seated in shoes or seatings f
formed of the same shape as the ends of the pipes, but distinct from them, and
as the metal of the arch expands or contracts, the pipes ride in the seatings,
and cause the crown of the arch to be raised or lowered, according to the
temperature.
In Fig. 5 I shew a modification of Fig. 1, the only difference being the
employment of oval pipes instead of round ones.
Having now described the nature and particulars of my said Invention, and
the manner in which the same is to be performed, I desire it to be understood
that I claim the improvements in the construction of bridges and arches as
herein described, and illustrated in the accompanying two Sheets of Drawings.
In witness whereof, I, the said Frederick Allen Leigh, have hereunto set
my hand and seal, this Twenty-eighth day of September, in the year
of our Lord One thousand eight hundred and sixty-five.
FREDERICK ALLEN LEIGH. (L.S.)
Signed, sealed, and delivered by
the within-named Frederick Allen
Leigh in the presence of
E. J. HUGHES,
Patent Agent,
Manchester.