IMPROVEMENTS IN THE CON- STRUCTION OF TUBULAR STEAM BOILERS
Year: 1858

page_text: LETTERS PATENT to Henry Harden, of Dundalk, in the County of Louth,
Ireland, Locomotive Superintendent to the Dublin and Belfast Junction
Railway Company, for the Invention of "IMPROVEMENTS IN THE CON-
STRUCTION OF TUBULAR STEAM BOILERS."
Sealed the 25th January 1859, and dated the 28th July 1858.
PROVISIONAL SPECIFICATION left by the said Henry Harden at the
Office of the Commissioners of Patents, with his Petition, on the 28th
July 1858.
I, HENRY HARDEN, of Dundalk, in the County of Louth, Ireland, Loco-
motive Superintendent to the Dublin and Belfast Junction Railway Company,
do hereby declare the nature of the said Invention for "IMPROVEMENTS IN THE
CONSTRUCTION OF TUBULAR STEAM BOILERS," to be as follows:-
The purpose of my Invention is to remove the objections to the use of iron
tubes in tubular steam boilers for locomotive and other purposes, thereby
securing the advantages belonging to such tubes, namely, cheapness and
durability, by combining therewith an advantage belonging to brass tubes, or
such as are formed of an alloy with copper. The principal objection against
iron tubes for steam boilers is their want of sufficient ductility to withstand
that amount of "drifting" at their ends necessary to secure a tight joint in
the tube plates, which objection does not apply to tubes formed of brass or an
alloy with copper. Now my Invention consists in constructing or retubing
tubula steam boilers with tubes of iron, having brass ends, or ends formed of

page_text: an alloy with copper or any other suitable ductile metal, which may be secured
to the iron part of the tube by brazing or otherwise, the ends of the tubes
formed of brass or other suitable ductile metal, being those parts of the tubes
which are secured in the tube plates, and which will stand the required
amount of "drifting" to form a steam-tight joint.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Henry Harden in the Great Seal Patent Office on the
26th January 1859.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, HENRY
HARDEN, of Dundalk, in the County of Louth, Ireland, Locomotive Super-
intendent to the "Dublin and Belfast Junction Railway Company," send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-eighth day of July, in the year of our Lord
One thousand eight hundred and fifty-eight, in the twenty-second year of
Her reign, did, for Herself, Her heirs and successors, give and grant unto
me, the said Henry Harden, Her especial license that I, the said Henry
Harden, my executors, administrators, and assigns, or such others as I, the
said Henry Harden, my executors, administrators, and assigns, should at any
time agree with, and no others, from time to time and at all times there-
after 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 "IMPROVE-
MENTS IN THE CONSTRUCTION OF TUBULAR STEAM BOILERS," upon the condition
(amongst others) that I, the said Henry Harden, 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 Henry Harden, 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
and accompanying Drawings (that is to say):-
:-
The purpose of my Invention is to remove the objections to the use of iron
tubes in tubular steam boilers for locomotive and other purposes, thereby

page_text: securing the advantages belonging to such tubes, namely, cheapness and
durability, by combining therewith an advantage belonging to brass tubes, or
such as are formed of an alloy with copper. The principal objection against
iron tubes for steam boilers is their want of sufficient ductility to withstand
that amount of "drifting" at their ends necessary to secure a tight joint in
the tube plates, which objection does not apply to tubes formed of brass or an
alloy with copper.
Now my Invention consists in contructing or retubing
tubular steam boilers with iron tubes having brass ends, or ends formed of an
alloy with copper, or that metal known to the trade as "homogeneous metal,"
or "homogeneous steel," or any other suitable ductile metal, which may be
secured to the iron part of the tube by brazing or otherwise, the ends of the
tubes being those parts of the tubes secured in the tube plates, and which will
stand the required amount of drifting to form a steam-tight joint.
I prefer to employ "homogeneous metal" or "homogeneous steel," which
I find to possess the requisite amount of ductility, and because it can be
secured to the end of the iron tube by "welding."
The accompanying Drawing shows by Fig. 1 and Fig. 2 longitudinal
sections of portions of tubes full size; a being the ends of the brass or an
alloy of copper, "homogeneous metal," or other sufficiently ductile metal;
and b, the iron parts of the tubes.
The Drawing shows the lengths of the ends (which may be more or less)
and the method of joining them which I prefer. It will be seen that in one
tube the ends (a) both externally and internally are uniform with the iron
part (6) of the tube, in the other the internal diameter of the ends (a) is less
than that of the iron part (b) of the tubes. I prefer the tube shown by
Fig. 1, first, because the point of contact of the two metals is more extensive,
and because it adds more strength to the tube where it is required, and
enables me to dispense with the use of the "ferrules" commonly employed in
securing the ends of the tubes in the tube plates of the boiler. In making
tubes like that shown by Fig. 1, the ends of the iron tubes (6) are "jumped"
to give the required increased thickness of metal, then prepared ends (a) are
"brazed" or welded to the ends of the iron tube (b) if the metal employed
will weld with iron.
I have now particularly described the nature of my Invention and the
modes of carrying the same into effect, and wish it to be understood that
I claim as my Invention the construction of locomotive or other tubular
steam boilers with iron tubes, having both ends (a) formed of brass or an
alloy with copper or other sufficiently ductile metal, for the purposes herein-
before set forth.

page_text: Secondly, the construction of locomotive or other tubular steam boilers with
iron tubes, having one end (a) or both ends (a) formed of that metal known
to the trade as "homogeneous metal" or "homogeneous steel."
Thirdly, the construction of locomotive and other tubular steam boilers
with iron tubes, having one or both their ends (a) of any sufficiently ductile
metal when such ends (a) are of greater thickness than the iron part (6) of
the tube, substantially as shown by Fig. 1 of the accompanying Drawings.
In witness whereof, I, the said Henry Harden, have hereunto set my
hand and seal, this 21st day of January, in the year of our Lord One
thousand eight hundred and fifty-nine.
H. HARDEN. (L.S.)