IMPROVEMENTS IN THE CONSUMPTION OR PREVENTION OF SMOKE
Year: 1855

page_text: LETTERS PATENT to John Henry Johnson, of. 47, Lincoln's Inn Fields,
in the County of Middlesex, and of Glasgow, North Britain, Gentleman,
for the Invention of "IMPROVEMENTS IN THE CONSUMPTION OR PREVENTION
OF SMOKE." A communication from Réné Garcon, of Paris, in the
Empire of France, Accountant.
Sealed the 26th Juno 1855, and dated the 21st April 1855.
PROVISIONAL SPECIFICATION left by the said John Henry Johnson at
Sur the Office of the Commissioners of Patents, with his Petition, on the
21st April, 1855.
93
I, JOHN HENRY JOHNSON, of 47, Lincoln's Inn Fields, in the County of
Middlesex, & of Glasgow, North Britain, Gentleman, do hereby declare the
nature of the said Invention for "IMPROVEMENTS IN THE CONSUMPTION OR PRE-
VENTION OF SMOKE," a communication to me from Réné Garcon, of Paris, in
the Empire of France, Accountant, to be as follows:-
This Invention relates to a peculiar construction and arrangement of steam
boilers & other furnaces, whereby the prevention of smoke is effected, and
consists in the employment of a second fire-place at the back of the main
furnace, but immediately behind the bridge, such fire-place being composed of
a number of fire bricks or lumps placed on edge at small intervals apart, the
front end of such bricks being bevilled or sloping, so as to allow the incan-
descent fuel to rest thereon. Beneath these bricks is formed a second ash-pit,
communicating with the main ash-pit by an open doorway. One or more
series of fire bricks are placed longitudinally in the passage from the furnace to
the flues, which bricks serve to divide the smoke, & by their intense heat

page_text: assist in consuming the gases and unburnt smoke. A cast-iron box or chamber
is fitted on each side of the main furnace, such boxes having perforations
formed therein to admit the air from the ash-pit & allow it to enter the
furnace. A number of spheres of fire clay may be placed in the flues, or
between the auxiliary boilers when such are employed, these spheres being
placed at distances apart, equal at least to their diameters. They are placed
between & rest loosely upon the circumferences of the two auxiliary boilers,
and are also placed between the sides of these boilers & the sloping sides of
the flues. These spheres become highly heated, and divide the smoke and gases
most effectually on their passage to the back flue. The sloping or bevilled fire
bricks are made of great length, so that as the smoke and gases pass through
the incandescent fuel thereon and traverse between their heated sides, they
may be effectually consumed before arriving at the chimney.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said John Henry Johnson in the Great Seal Patent Office on the
20th October 1855.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
HENRY JOHNSON, of 47, Lincoln's Inn Fields, in the County of Middlesex,
and of Glasgow, North Britain, Gentleman, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-first day of April, in the year of our Lord
One thousand eight hundred and fifty-five, in the eighteenth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me,
the said John Henry Johnson, Her special license that I, the said John
Henry Johnson, my executors, administrators, and assigns, or such others
as I, the said John Henry Johnson, my executors, administrators, or 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 "Iм-
PROVEMENTS IN THE CONSUMPTION OR PREVENTION OF SMOKE," a communication
from Réné Garçon, of Paris, in the Empire of France, Accountant, upon the
condition (amongst others) that I, the said John Henry Johnson, by an instru-
ment 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

page_text: Office within six calendar months next and immediately after the date of the
said Letters Patent.
NOW KNOW YE, that I, the said John Henry Johnson, do hereby
declare the nature of the 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 accompanying Drawings, and to
the letters and figures marked thereon, that is to say :-
The said Invention relates to a peculiar construction and arrangement of
furnace, whereby the prevention of smoke is effected, and consists principally
in the employment of a second fire-place behind the bridge of the furnace, such
fire-place being composed of a number of fire bricks or lumps placed on edge
in a longitudinal direction at small intervals apart, the front end of such
bricks being bevilled or sloping, to allow the incandescent fuel to rest thereon.
Beneath this second fire-place is formed a second ash-pit, communicating with
the main ash-pit by means of an arch, which may be readily opened when
requisite. A cast-iron chamber or arch is placed on each side of the main
furnace, such chamber or arch being perforated to admit the air from the ash-
pit, and allow it to enter at the sides of the fire. A number of spheres of
fire clay are placed on the bridge between it and the bottom of the boiler,
or auxiliary boilers when such are employed. These spheres are placed at
distances apart, at least equal to their diameter, and so arranged as to divide
the smoke and gases on their passage to the back flue, and becoming highly
heated, greatly assist the combustion of the same. The sloping or bevilled fire
bricks are made of great length, so that as the smoke and gases pass over
the incandescent fuel thereon and between their heated sides or surfaces, they
become effectually consumed before arriving at the chimney.
And in order that the said Invention may be fully understood, I shall now
proceed particularly to describe the same; and for that purpose I shall refer to
the several Figures on the Sheet of Drawings hereunto annexed, the samo
letters of reference indicating corresponding parts throughout all the Figures.
Figure 1 is a vertical and longitudinal section of a furnace with my Invention
applied thereto; Figure 2 is a transverse section through the main fire-place;
and Figure 3 is a horizontal section through the line A, B, in Figure 2. A is
the main fire-place; B, B, the auxiliary boilers; and C, C, the main boiler, sup-
ported upon the brickwork D, D. a, a, are the cast-iron perforated chambers
for the admission of air from the ash-pit to the sides of the fire. Upon the
bridge 6 and at each side of the fire-place are two projections c, c, in fire brick,
extending from the walls of the furnace to the sides of the auxiliary boilers
B, B, so as to produce a slight contraction at this point, causing the hot gases

page_text: and air to become mixed and to pass between the spheres of fire clay d, d,
which by their position become greatly heated, and by their power of radiation
in all directions cause the air and products of combustion to become thoroughly
mixed and consumed; e; e, is the second fire-place, composed of plates or
lumps of fire clay, of the form' shewn in Figures 1 and 3, placed on edge, at
short intervals apart. When the fire is well 'sustained, the plates e attain a
white heat, and by their radiation not only complete the combustion of the
smoke and gases; but also greatly assist the heating of the boiler, and conse-
quently effect'a a considerable economy in the consumption of fuel. The plates
e and the "bridge b are supported upon arches, which are filled in with light
walls ff, which prevent the the passage of the air or flame under the arch, and
can be easily removed and replaced when necessary for repairing or cleaning
out the second ash-pit, or (if preferred) they may be provided with doors
closing air-tight, or nearly so."
Having now described and particularly ascertained the nature of the 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 arrangements 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 the said Invention; but what I consider to be
novel and original, and therefore claim as the Invention secured to me by tho
herein-before in part recited Letters Patent, is,-
Firstly, the construction and application of the fire-place of fire bricks, or
vertical slabs of fire clay, of the form shewn and described.
1
Secondly, I claim the peculiar construction and arrangement of the air
passages at the sides of the furnace.
Thirdly, I claim the use of projections from the walls for the purpose of
contracting the furnace at the bridge.
And, fourthly, the application at the bridge of the spheres of fire clay for
mixing the air and products of combustion, and assisting the consumption of
the same by their radiation of heat.
In witness whereof, I, the said John Henry Johnson, have hereunto
set my hand and seal, the Twentieth day of October, One thousand
eight hundred and fifty-five.
RUNDY
TATTO
J. HENRY JOHNSON.