IMPROVEMENTS IN THE FIRE-BOXES OF LOCOMOTIVE AND OTHER TUBULAR BOILERS
Year: 1873

page_text: LETTERS PATENT to George Spencer, Civil Engineer, of 77, Cannon
Street, London, and Walter Mackersie Smith, Engineer, of
Henniker Cottage, Chandos Road, Stratford, Essex, for the In-
vention of "IMPROVEMENTS IN THE FIRE-BOXES OF LOCOMOTIVE AND OTHER
TUBULAR BOILERS."
Scaled the 8th July 1873, and dated the 26th February 1873.
PROVISIONAL SPECIFICATION left by the said George Spencer and
Walter Mackersic Smith at the Office of the Commissioners of
Patents, with their Petition, on the 26th February 1873.
WO, GEORGE SPENCER, Civil Engineer, of 77, Cannon Street, London,
and WALTER MACKERSIE SMITH, Engineer, of Henniker Cottage,
Chandos Road, Stratford, Essex, do hereby declare the nature of the
said Invention for "IMPROVEMENTS IN THE FIRE-BOXES OF LOCOMOTIVE AND OTHER
TUBULAR BOILERS," to be as follows:-

page_text: being opposite to and in connection with the boiler tubes, the division
between the two chambers being formed by a horizontal or inclined mid-
feather formed by plates between which the water of the boiler circulates,
being in connection with it. The two chambers are connected by tubes
in the midfeather, which may be either cylindrical or conical. The 5
upper plate of the midfeather may be connected with the top plate of
the fire-box by cylindrical or conical tubes; both chambers are furnished
with doors, the bottom one for firing, and the top one for access to the
tubes; air may be admitted by either or both doors.
2nd. In making the ring round tho fire-door hole hollow, the open
part to be kept outside, so as to enable both sides to be fixed with rivets,
which rivets can be easily examined and renewed, if necessary. The
ring may be bored out together with the fire-box plates, to which may
be fitted a turned ring to be driven in tight. This ring may also be cut
at the top, and tightened by means of a wedge being inserted in it; this 1
ring will also serve to protect the fire-box plates from the fireman's
tools.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said George Spencer and Walter Mackersic Smith
in the Great Seal Patent Office on the 23rd August 1873.
TO ALL TO WHOM THESE PRESENTS SHALL COME, we, GEORGE
SPENCER, Civil Engineer, of 77, Cannon Street, London, and WALTER
MACKERSIE SMITH, Engineer, of Henniker Cottage, Chandos Road,
Stratford, Essex, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters 1
Patent, bearing date the Twenty-sixth day of February, in the year
of our Lord One thousand eight hundred and seventy-three, in the
thirty-seventh year of Her reign, did, for Herself, Her heirs and suc-
cessors, give and grant unto us, the said George Spencer and Walter
Mackersie Smith, Her special licence that we, the said George Spencer 3
and Walter Mackersic Smith, our exccutors, administrators, and assigns,
or such others as we, the said George Spencer and Walter Mackersio
Smith, our executors; administrators, and assigns, should at any time
agree with, and no others, from time to time and at all times there-

page_text: after during the term therein expressed, should and lawfully might make,
use, excrcise, and vend, within the United Kingdom of Great Britain
and Ireland, the Channel Islands, and Isle of Man, an Invention for
"IMPROVEMENTS IN THE FIRE-BOXES OF LOCOMOTIVE AND OTHER TUBULAR BOILERS,”
upon the condition (amongst others) that we, the said George Spencer
and Walter Mackersie Smith, our executors or administrators, by an
instrument in writing under our, or their, or one of their lands and
scals, should particularly describe and ascertain the nature of the said
Invention, and in what manner the same was to be performed, and causo
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 we, the said George Spencer and Walter
Mackersic Smith, do hereby declare the nature of our said Inven-
tion; and in what manner the same is to be perfornied, to bo par-
ticularly described and ascertained in and by the following statement:-
'
Our improvements consist,-
.1st. In making the fire-box in two chambers, the lower ono containing
the usual fire-grate for the combustion of the fuel, the upper chamber
being opposite to and connection with the boiler tubes, the division
between the two chambers being formed by a horizontal or inclined mid-
feather formed by plates, between which the water of the boiler
circulates, being in connection with it. The two chambers aro connected
by tubos in the midfeather, which may be either cylindrical, or conical,
or other convenient shape. The upper plate of the midfeather may be
connected with the top plate of the fire-box .by cylindrical, conical, or
other shaped tubes or water spaces. Both chambers are furnished with
doors, the bottom one for firing, and the top one for access to the tubes;
air may be admitted by either or both doors.
-
2ndly. A method of forming fire-holo rings hollow, with the hollow
towards the opening of fire-holes, and in methods for protecting the
samo from friction.
In the annexed Drawings several modifications of our Invention are
shown.

page_text: -
In Figs. 1, 2, 3, 4, 5, 8, 9, 10, and 11, B shows the midfeather. In
the same Figures the tubes or rings connecting the upper and lower
chambers are marked O.
Instead of the tubes or rings marked C, open spaces such as are shown
dotted in Fig. 3 and marked O' may be used.
In Figs. 1, 2, 3, 9, 10, and 11 D shows the tubes or spaces connecting
the midfeather with the top of the fire-box, which tubes or spaces convoy
the steam to the top of the boiler; in the above Figures E shows the
top chamber.
The form of the different parts described may be varied, the object of 1
the arrangements shown being to increase the heating surface of the
fire-box, and to improve the combustion, and economise the fuel.
Figs. 6, 7, and 8 show our method of forming the fire-door ring; G
shows a section of the fire-door ring; I, I, are the plates of the fire-box
to which the ring G is riveted; the space is closed by the ring H.
In witness whereof, wo, the said George Spencer and Walter
Mackersic Smith, have hereunto set our hand and seal, this
Twenty-third day of August, in the year of our Lord 1878.
GEORGE SPENCER.. (L.S.)
1