IMPROVEMENTS IN GIRDERS TO BE USED IN BRIDGES, SUBWAYS, VIADUCTS, DESCRIPTION OF BUILDING AND OTHER 0 RAILWAY WORKS, AND EVERY STRUCTURES
Year: 1870

page_text: LETTERS PATENT to Constantine Henderson, of No. 8, Gracechurch
Street, in the City of London, Architect, for the Invention of
"IMPROVEMENTS IN GIRDERS TO BE USED IN BRIDGES, SUBWAYS, VIADUCTS,
DESCRIPTION OF BUILDING AND OTHER
0 RAILWAY WORKS, AND EVERY
STRUCTURES."
Sealed the 11th November 1870, and dated the 2nd September 1870.
PROVISIONAL SPECIFICATION left by the said Constantine Henderson
at the Office of the Commissioners of Patents, with his Petition,
on the 2nd September 1870.
I, CONSTANTINE HENDERSON, of No. 8, Gracechurch Street, in the
City of London, Architect, do hereby declare the nature of the said
Invention for "IMPROVEMENTS IN GIRDERS TO BE USED IN BRIDGES, SUBWAYS,
VIADUCTS, RAILWAY WORKS, AND EVERY DESCRIPTION OF BUILDING AND OTHER
STRUCTURES," to be as follows:-
My improvements in the construction of girders to be used in
arched structures, bridges, subways, viaducts, railway works, and every
description of buildings and other structures consist in forming the said

page_text: girders of one straight flitch or web of iron or steel. The ends thereof
are formed with cross pieces, any given length, secured to the web or
flitch at right angles, or the ends are enlarged beyond the thickness of
the flitch or web, so as to form a secure holding which shall answer the
same purpose as the aforesaid cross pieces. The cross pieces or holdings
are fitted into slots prepared in the cast-iron blocks or skewbacks which
form the abutments of the arch, and the inner sides of the said skewbacks
are made to correspond with the angle formed by the radius of the arch.
In another form, instead of having detached skewbacks they are entirely
done away with, and in lieu thereof will be welded on to each end of
the web or flitch upon either side pieces of iron or other suitable metal.
The inner sides of these pieces will form the angle to suit the radius of
the arch, & thus become the abutments or skewbacks thereof.
In the application of these girders to arched structures for which they
are specially adapted I place the girders & skewbacks in position on
the piers or supports and spring the arch from the skewbacks or abut-
ments, the tendency of the arch to force the abutments apart being
counteracted by the girders in a tensile direction, and not transversely.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Constantine Henderson in the Great Seal Patent 2
Office on the 17th November 1870.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, CONSTANTINE
HENDERSON, of No. 8, Gracechurch Street, in the City of London,
Architect, send. greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her 2
Letters Patent, bearing date the Second day of September, in the year
of our Lord One thousand eight hundred and seventy, in the thirty-
fourth year of Her reign, did, for Herself, Her heirs and successors, give
and grant unto me, the said Constantine Henderson, Her special licence
that I, the said Constantine Henderson, my executors, administrators,
and assigns, or such others as I, the said Constantine Henderson, 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

page_text: vend, within the United Kingdom of Great Britain and Ireland, the
Channel Islands, and Isle of Man, an Invention for "IMPROVEMENTS IN
GIRDERS TO BE USED IN BRIDGES, SUBWAYS, VIADUCTS, RAILWAY WORKS, AND
EVERY DESCRIPTION OF BUILDING AND OTHER STRUCTURES," upon the condition
(amongst others) that I, the said Constantino Henderson, my executors
or administrators, by an instrument 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 Constantine Henderson, 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:-
My Invention for improvements in girders to be used in bridges,
subways, viaducts, railway works, and every description of building and
other. structures, refers to a peculiar mode of constructing same, the
principle thereof enabling me to obtain the maximum strength out of
the material of which the girder is composed. The girder is formed of
a web or flitch of metal having the ends enlarged or formed into a T or
any other suitable shape. The web or flitch is then secured into skew-
backs or abutments prepared to receive the same. The skewbacks or
abutments are either cast or wrought metal having slots, tenons, or
openings prepared in them to receive the enlarged ends of the web
or flitch which tics or connects the abutments or skewbacks. The inner
side of the skewbacks or abutments are so formed as to suit the radius
of the arch or arches to be used. From the abutments or skewbacks the
arch of brick, stone, iron, wood, or any suitable material is constructed
on each side of the web. By this mode of construction it will be readily
seen that the arch or arches carries the entire weight or burden, whilst
the metal of my girder or the web or flitch is relieved from all vertical
pressure, and is thereby only subjected to a tensile strain and operates
as a tie to retain the thrust of the arch or arches. The abutments or
skewbacks may be connected by the flitch or web in various ways. In
some instances the abutments are welded on to the ends of the web or
flitch as will be more particularly described in the Drawing hereto
annexed.

page_text: the intended radius of the arch and secured to the angle pieces and the
web or flitch by welding or pius.
Fig. 13 is elevation of the plan Fig. 12.
Fig. 14 is a section of the girder shewing the arch and web cut
through.
Having now described the nature of my said Invention, and the
manner in which the same is or may be carried into effect, I would
observe in conclusion that what I consider to be novel and original, and
therefore claim as the Invention secured to me by the hercin.before in
part recited Letters Patent is,-
4
First. The peculiar mode of connecting by a web or flitch of rolled
or cast metal two or more abutments or skewbacks so as to receive an
arch of brick, stone, iron, wood, or any other suitable material.
Secondly. The peculiar formation of skewbacks or abutments, the
various methods shewn on the Drawings being some of the most
simple modes to adopt. In some instances detached skewbacks or
abutments will not be used, and in their stead abutments forming skew-
backs will be welded on to the ends of the webs or flitches as herein
described.
In witness whereof, I, the said Constantine Henderson have here-
unto set my hand and seal, this Twenty-second day of October,
in the year of our Lord Oue thousand eight hundred and
seventy.