IMPROVEMENTS IN THE CONSTRUCTION OF STEAM GENERATORS, APPLICABLE ALSO TO THE CON-. STRUCTION OF CONDENSERS, THE HEATING OF WATER GENERALLY, AND TO THE WARMING OF BUILDINGS
Year: 1865

page_text: LETTER'S PATENT to John Henry Johnson, of 47, Lincoln's Inn Fields, in
1
the County of Middlesex, Gentleman, for the Invention of" IMPROVEMENTS
IN THE CONSTRUCTION OF STEAM GENERATORS, APPLICABLE ALSO TO THE CON-.
STRUCTION OF CONDENSERS, THE HEATING OF WATER GENERALLY, AND TO THE
WARMING OF BUILDINGS."-A communication from abroad by Joseph
Harrison, junior, and Thomas Luders, both of Philadelphia, in the
United States of America.
Sealed. the 6th April 1866, and dated the 10th October 1865.
PROVISIONAL SPECIFICATION left by the said John Henry Johnsoni at
the Office of the Commissioners of Patents, with his Petition, on the
10th October, 1865.
I, JOHN HENRY JOHNSON, of 47, Lincoln's Inn Fields, in the. County of
Middlesex, Gentleman, do hereby declare the nature of the said Invention
for "IMPROVEMENT IN THE CONSTRUCTION OF STEAM GENERATORS, APPLICABLE
ALSO TO THE CONSTRUCTION OF CONDENSERS, THE HEATING OF WATER GENERALLY,
AND TO THE WARMING OF BUILDINGS," a communication to me from abroad by
Joseph Harrison, junior, and Thomas Luders, both of Philadelphia, in the
United States of America, to be as follows:-
*This Invention relates to improvements on the Invention for, which Letters,
Patent were granted to me on or about the 30th of August 1859, No. 1970,

page_text: whereby greater simplicity is obtained, inasmuch as several of the numerous
tye bolts and joints mentioned in the Specification of the Patent above referred
to are wholly or in part omitted.
According to this Invention for the purpose of making what may be called
a slab or section of a boiler or condenser, it is ordinarily proposed to make
the entire slab or section in one piece, either by casting or otherwise forming
together a number of hollow spherical or other shaped chambers. At both
ends of the slab are openings closed by caps, which openings are requisite in
casting for supporting and venting the cores, and for facilitating the cleaning
of the boiler when in use. Transverse openings are formed at one or more
of the corners of the slab with a view to forming steam and water connections
with adjoining slabs of like construction, for which purpose rings or castings
having spherical junction surfaces corresponding to similar spherical joints on
the slabs are interposed so as to form the communication required, the whole
being drawn tightly together by long screw bolts passing transversely through
the series of slabs at their corners. As no special tye bolts whatever are
required for the individual slabs, it follows that considerable economy and
simplicity of construction,are obtained. Steam water attachments at the
tops and bottoms of the slabs are formed where requisite by branch pipes,
which may be cast on one or more of the joint rings above referred to. By
making the joints spherical rigidity is avoided, and any slight variation in the
slabs arising from unequal expansion is allowed for. For stationary boilers it
is preferred to set the series of slabs forming the generator in brickwork in
any manner best adapted to suit the form of boiler adopted, but when com-
bining such slabs into forms suitable for marine or locomotive purposes, it is
proposed to close up the spaces between the spheres and round the margins
or edges of the exterior slabs by means of thin webs cast on the slabs, and
thereby to form tight metal walls at the outside of any combination of slabs,
and dispensing in part or entirely with the use of brick covering. The slabs
are by preference placed edgewise overthe furnace, but atan angle of about 45°,
the lower corner of each slab resting on a chair or bearer. The gases from
the furnace play between the several slabs, and before passing out to the
chimney are made to descend to the lowest points of the slabs. Where single
slabs are required containing a greater number of spheres that can be cast or
handled with facility in one piece, it is proposed to make such slabs in parts as
large as may be most convenient, the parts to be formed into entire slabs by
means of joints and bolts, or otherwise. For example,a large slab may be com-
posed of 4 smaller ones, two being placed parallel, or edge to edge, the other
two forming thetop and bottom of the compound slab being laid across the ends

page_text: of these two parallel sections. The bolts tieing the sections together may
either run throughout the entire length of the slab or be arranged in shorter
lengths. By this system facility is afforded for allowing any section of the
slabs thus made up to be taken out and renewed in case of defect without
interfering with the other portion of the slab. It is also proposed to introduce
tubes or flues into the slabs extending along the interior of each row of
spheres, excepting the bottom row nearest the fire, which may be left free for
the better circulation of the water, and for the removal of the scale or deposit
By this arrangement the steam generating and superheating surface of the
boiler will be greatly augmented.
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
10th April 1866.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN HENRY
JOHNSON, of 47, Lincoln's Inn Fields, in the County of Middlesex, Gentleman,
send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Tenth day of October, in the year of our Lord One
thousand eight hundred and sixty-five, in the 29th 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 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 "IMPROVEMENTS IN
THE CONSTRUCTION OF STEAM GENERATORS, APPLICABLE ALSO TO THE CONSTRUCTION
OF CONDENSERS, THE HEATING OF WATER GENERALLY, AND TO THE WARMING OF
BUILDINGS," a communication to me from abroad by Joseph Harrison, junr.
and Thomas Luders, both of Philadelphia, in the United States of America,
upon the condition (amongst others) that I, the said John Henry Johnson, my
executors or administrators, by an instrument in writing under my hand and
seal, should particularly describe and ascertain the nature of the said
Invention, and in what manuer the same was to be performed, and cause the

page_text: 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 John Henry Johnson, do hereby declare
the nature of the said Invention, and in what manner the same is to be per-
formed, 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 improvements on the Invention for which
Letters Patent were granted to me on or about the Thirtieth of August,
One thousand eight hundred and fifty-nine, No. 1970, whereby greater
simplicity is obtained, inasmuch as several of the numerous tie bolts and joints
mentioned in the Specification of the Patent above referred to are wholly or
in part omitted. According to this Invention for the purpose of making
what may be called a slab or section of a boiler or condenser, it is ordinarily
proposed to make the entire slab or section in one piece, either by casting or
otherwise forming together a number of hollow spherical or other shaped
chambers. At both ends of the slab are openings closed by caps, which
openings are requisite in casting for supporting and venting the cores, and for
facilitating the cleaning of the boiler when in use. Transverse openings are
formed at one or more of the corners of the slab with a view to forming
steam and water connections with adjoining slabs of like construction, for
whichpurposeringsorcastingshavingsphericaljunctionsurfacescorresponding
to similar spherical joints ou the slabs are interposed so as to form the com-
munication required, the whole being drawn tightly together by long screw
bolts passing transversely through the series of slabs at their corners. As no
special tie bolts whatever are required for the individual slabs, it follows that
considerable economy and simplicity of construction are obtained. Steam and
water attachments at the tops and bottoms of the slabs are formed where
requisite by branch pipes which may be cast on one or more of the joint rings
above referred to. By making the joints spherical rigidity is avoided, and any
slight variation in the slabs arising from unequal expansion is allowed for.
For stationary boilers it is preferred to set the series of slabs forming the
generatorin brickwork, in any manner best adapted to suit the form of boiler
adopted, but when combining such slabs into forms suitable for marine or
locomotive purposes, it is proposed to close up the spaces between the spheres
and round the margins or edges of the exterior slabs by means of thin webs cast
on the slabs, and thereby to form tight metal walls at the outside of any
ecombination of slabs, and dispensing in part or entirely with the use of brick
covering. The slabsareby preferenceplacededgewiseover the furnace, but atan

page_text: angle of about 45°, the lower corner of each slab resting on a chair or bearer.
The
gases from the furnace play between the several slabs, and before passing
out to the chimney are made to descend to the lowest points of the slabs.
Where single slabs are required containing a greater number of spheres than
can be cast or handled with facility in one piece,it is proposed to make such
slabs in parts as large as may be most convenient, the parts to be formed into
entire slabs by means of jointsand bolts, or otherwise. For example,a large slab
may be composed of four smaller ones,two being placed parallel or edge to
edge, the other two forming the top and bottom of the compound slab being
laid across the ends of these two parallel sections, the bolts tieing the sections
together may either run throughout the entire length of the slab or be
arranged in shorter lengths. By this system facility is afforded for allowing
any section of the slabs thus made up to be taken out and renewed in case of
defect without interfering with the other portion of the slab. It is also
proposed to introduce tubes or flues into these slabs extending along the
interior of each row of spheres, excepting the bottom row nearest the fire,
which may be left free for the better circulation of the water, and for the
removal of the scale or deposit. By this arrangement the steam generating
and superheating surface of the boiler will be greatly augmented.
And in order that the said Invention may be fully understood I shall now
proceed more particularly to describe the same, and for that purpose
shall refer to the several Figures on the annexed Sheets of Drawings, the
same letters of reference indicating corresponding parts inallthecorresponding
Figures.
Figure 1 on Sheet 1 of the Drawings represents in partial section and side
elevation a slab or "section" of a boiler of sixty-four hollow spheres, each
sphere of about eight inches exterior diameter,and of any required thickness
made in a single piece. At both ends of the slab are a series of openings
closed by screw caps a, as shown; these openings being needed in casting
for supporting and venting the cores, and also for cleaning the boiler when iu
use. b,b, are transverse openings through the slab hereafter to be explained.
Figure 2 shows an end view of three of these slabs partly in section, and
shows also the mode of connecting the slabs together for forming a steam
gen erator, any number of these slabs may be set vertically edgewise beside
each other,and in any required position as to their lengthwise direction.
Between the slabs at one or more corners, or at any other points, are to be
placed the castings d, d, against the open in geb, b. These castings are fitted
to the slabs, so that when drawn together by the long bolts e, e, the joints
become tight, and the intervened castingsd forma steam-connection at or near

page_text: the top, and a water connection at or near the bottom of the series of slabs,
and can also be used for other water and steam attachments by branches f, f¹,
that may be affixed or cast thereon. In practice rigidity is found objection-
able in the cross connections for water and steam between the slabs, for the
reason that unequal expansion of the different parts tend to impair the
tightness of the joints when rigid. By reference to the sectional detail Figure 3
(Sheet 2), which is made about one-fourth the working size,it will be seen that
the joints on the slabs and intermediate pieces d,d,have a curved or spherical
line struck with radii that proceed from the centres of the spheres, by means
of which the slight variation of the slabs resulting from unequal expansion is
accommodated, for although there may occur some movement of the surfaces
at the joints they would remain tight. For stationary purposes it is preferred
to set the improved boiler in brickwork in manner adapted to its peculiar
form, but in combining the above described slabs or series of spheres into
forms suitable for marine or locomotive purposes, it is proposed for the exterior
slabs to close up the spaces between the spheres and around the margins, by
means of thin webs g, cast on the slabs by proper joinings at the edges of
these webs on the slabs to form tight metal walls at the outside of
any com-
bination of slabs,dispensing thereby in part or altogether with the use of a
brick covering. Figure 4 (Sheet 2) shows the ordinary mode of setting the
improved boiler,in which it will be seen that the interior of the spheres and
their connecting necks are filled with water up to the water line, whilst that
portion of the spheres above the water line in each slab constitutes the steam
chamber,the slabs being connected as above explained by water and steam
communications common to the whole series combined into one boiler.The
gases from the fire ascend into the spaces between the spheres, circulating
through them, and in part giving heat to the upper spheres, thereby super-
heating the steam contained therein,and in order that the largest amount of
water surface may be brought into contact with the heat generated in the
furnace, the gases before entering the chimney are made to pass out of the
slabs at their lowest point, as shown by the arrows in Figure 4. In putting
those slabs together to form a steam generator I intend to combine them in
such manner and to strengthen them by such means as may best suit the
peculiar circumstances of the case, whether made up into a compact mass or in
chambers or flues, forming in their combination an efficient steam generator.
Should single slabs be required containing a greater number of spheres than
can be cast or handled with facility in one piece,then I propose to make such
slabs in parts as large as may be most convenient, the parts to be formed into
entire slabs by means of joints and bolts.

page_text: .
Figure 4, Sheet 2, shows this construction of slab. In this case I make
the entire slab of four pieces or sections marked A, B, C, D, with joints
through the necks at the lines E, E, F, F. In this arrangement the sections
B and D are precisely similar in form, and in case of need the lower section
may be placed at the top, or the top section at the bottom; or these sections
may be turned at pleasure, so that the top row of spheres in either of them
may be put at the bottom, or vice versa. In making slabs in this manner in
sections of four or more, the bolts tying them together may either run
throughout the entire length, as in the slabs made of small units, or they may
be arranged in shorter lengths, care being taken that the joints are held
firmly and tightly together. The object in making slabs as here described is
to allow any section of the slabs thus made up to be taken out and renewed
in case of defect without throwing away the injured portion of the slab.
Figure 5 (Sheet 3) represents a sectional elevation of a modification of the
slab above described, fitted up in brick setting to form a boiler. In this the
bolts and joints are omitted as heretofore described, and in lieu of bolts
passing through the slabs, tubes, or flues of any required diameter are inserted
longitudinally through each series of spheres as shown at 9, 9, except the
bottoru line nearest the fire, which it is preferred to leave free for better
circulation of the water and for removal of scale or deposit. The heat from
the furnace / ascending between the spheres in the direction of the arrows
finds an-outlet at the lower end of the boiler, whence turning into the tubes g
it still follows the direction of the arrows until at the upper eud the chimney i
is reached, through which the gases pass off into the atmosphere. By the
introduction of the flues or tubes throughout the length of the slab, or com-
bination of spheres), and by the passage of the heated vapour through these
tubes a large addition is made to the steam making and superheating surface
of the boiler, without any additional size and but little additional weight.
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 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 application and use to and in the construction of steam generators,
condensers, and water heating apparatus of a series of cast-iron hollow slabs
constructed and combined together substantially in the manner herein-before
described in reference to Figures 1 and 2 of the Drawings annexed.
Second, the application and use of intermediate rings or castings having
spherical or curved junction faces for forming cross connections for water and

page_text: steam at one or more corners of the above described slabs, whether such slabs
consist each of a single casting, or be built up or composed of two or more
smaller castings,substantially as and for the purpose herein-before described
in reference to Figure 3 of the Drawings annexed.
Third, the constructing the above slabs of two or more smaller slabs held
together by long tie bolts, substantially as and for the purpose herein-before
described in reference to Figure 4 of the Drawings annexed.
Fourth,the combination with the slabs above mentioned of a thin metal web,
for the purpose of making a tight wall or casing for boilers, in the setting of
which it is desired wholly or in part to dispense with brickwork, substantially
as herein-before described in reference to Figures 1 and 2 of the Drawings
annexed:..
i
Fifth, the combination with the above-mentioned slabs of internal tubes or
flues,substantially as and for the purpose herein-before described in reference
to Figure 5 of the Drawings annexed.
In witness whereof, I, the said John Henry Johnson, have to this my
Specification set my hand and seal, the Tenth day of April; in the
year of our Lord One thousand eight hundred, and sixty-six.
J. HENRY JOHNSON... (L-S.)