IMPROVEMENTS IN AGRICULTURAL AND OTHER STEAM ENGINES
Year: 1852

page_text: LETTERS PATENT to William Allchin, of the firm of William
Allchin and Son, of the Globe Steam Engine Works, North-
ampton, in the County of Northampton, Engineers, for the In-
vention of "IMPROVEMENTS IN AGRICULTURAL AND OTHER STEAM
ENGINES."
Sealed the 8th June 1853, and dated the 9th December 1852.
PROVISIONAL SPECIFICATION left by the said William Allchin
at the Office of the Commissioners of Patents, with his Petition,
on the 9th December 1852.
I, WILLIAM ALLCHIN, do hereby declare the nature of the said
Invention for "IMPROVEMENTS IN AGRICULTURAL AND OTHER STEAM
ENGINES" to be as follows:-
This Invention relates principally to an improved arrangement
of the fire box, smoke box, and boiler of portable steam engines.
The fire box is fitted with a division piece or mid feather, which

page_text: extends nearly the entire length of the fire bars. By this arrange-
ment a great consumption of smoke is effected, the system of al-
ternate firing being adopted. The smoke box is fitted with an
annular space round its interior, for the purpose of receiving the
feed water and heating it previous to its being conveyed to the
boiler, at the same time preventing the smoke box from becoming
overheated. In order to materially increase the heating surface,
the smoke box is extended back to the fire box, leaving a space all
round the barrel of the boiler. The chimney, in this arrangement,
is of course fitted at the fire-box end of the boiler, and close to the
fire-box. In this way the heated air, after traversing the ordinary
boiler tubes, proceeds along the outside of the boiler by the ex-
tended portion of the smoke box, and thence by the chimney in the
ordinary manner. The cylinder and valves are contained within a
chamber on the top of the fire-box end of the boiler, the steam ex-
hausting into this chamber, and consequently surrounding the
cylinder and keeping it hot.
The proximity of the chimney affords facility for the escape of
the steam by a blast pipe connected with the exhaust chamber con-
taining the cylinder.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said William Allchin in the Great Seal Patent Office
on the 9th June 1853.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I,
WILLIAM ALLCHIN, of the firm of William Allchin and Son, of the
Globe Steam Engine Works, Northampton, in the County of North-
ampton, Engineers, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Ninth day of December, in the
year of our Lord One thousand eight hundred and fifty-two, in
the sixteenth year of Her reign, did, for Herself, Her heirs and

page_text: successors, give and grant unto me, the said William Allchin, Her
special license that I, the said William Allchin, my executors, ad-
ministrators, and assigns, or such others as I, the said William
Allchin, 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
night 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 AGRICULTURAL AND OTHER
STEAM ENGINES," upon the condition (amongst others) that I, the
said William Allchin, 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 per-
formed, 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 William Allchin, 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, reference being had to the ac-
companying Drawings, and to the letters and Figures marked
thereon (that is to say):
My said Invention relates to the so arranging and constructing
certain details of agricultural and other steam engines, that a great
portion of the loss ordinarily sustained from the radiation of the
heat, and the condensation by exposure to the external atmosphere
may be prevented. Figure 1, on my Sheet of Drawings, is a longi-
tudinal section of a steam boiler adapted for a locomotive or port-
able engine as fitted up according to one modification of my
improvements. Figure 2, is a plan or horizontal section of the
same corresponding. Figure 3, is a transverse section of the
boiler, shewing the fire box, exhaust steam chamber, and smoke
box; and Figure 4, is a transverse section, shewing two separate
halves, and looking thereon in reverse directions from the longi-

page_text: tudinal centre of the boiler. The boiler is constructed in the
ordinary tubular form, with a rectangular fire box A, and fluc
tubes B, leading to the smoke box C, at the opposite end, the barrel
portion of the boiler containing these tubes being surrounded by an
exhaust steam jacket or annular casing D, to screen the heated
surfaces from the external atmosphere. This steam space D, is
kept full of steain by a pipe led either from the exhaust passages of
the engine or direct from the exhaust chamber F. In the example
which I have herein given the exhaust or waste steam is used, the
actuating cylinder of the engine being set in the overhead case F,
from which case a branch pipe G, conveys the used steam direct to
the steain casing D. The bulk of the exhaust steam passes off to
the chimney H, by the long pipe I, or by the casing D, to aid the
draught in the usual manner. The cylinders and valves are wholly
covered in by the casing F; and, as the waste steam is exhausted
into the interior of the casing, all the parts requiring to be kept
hot are thus well enveloped in the heated vapour, and the loss by
radiation and condensation is materially reduced; and this system
of economising fuel and steam affects as well the top of the outside
fire box, which is kept warm by the chamber F thereon.
Having now described and particularly ascertained the nature of
my said Invention, and the manner in which the same is or may
be used or carried into effect, I would observe, in conclusion, that I
do not confine or restrict myself to the precise details or arrange-
ments which I have had occasion to describe or refer to, as many
variations may be made therefrom without deviating from the
principles or main features of my Invention, but what I consider to
be novel and original, and therefore claim as the Invention secured
to me by the herein-before in part recited Letters Patent, is,-
First, the general arrangement and construction of steam
engines as herein-before described.
Second, the system or mode of preventing the loss of heat by
the use of an external annular steam chamber encircling the barrel
or cylindrical portion of the boiler.
Third, the system or mode of economising the heat by envelop.

page_text: ing the cylinders, valves, and pipes, or steam ways in an exhaust
steam chamber as herein-before described.
In witness whereof, I, the said William Allchin, have hereunto
set my hand and seal, the Eighth day of June, One thou-
sand eight hundred and fifty-three.
WILLIAM ALLCHIN. (L. s.)