IMPROVEMENTS IN THE ARRANGEMENT OR CONSTRUCTION OF STEAM ENGINES AND BOILERS
Year: 1858

page_text: LETTERS PATENT to John Elder, of Glasgow, in the County of Lanark,.
North Britain, Engineer, for the Invention of "IMPROVEMENTS IN THE
ARRANGEMENT OR CONSTRUCTION OF STEAM ENGINES AND BOILERS."
Sealed the 13th July 1858, and dated the 29th January 1858.
PROVISIONAL SPECIFICATION left by the said John Elder at the Office
of the Commissioners of Patents, with his Petition, on the 29th January
1858.
I, JOHN ELDER, of Glasgow, in the County of Lanark, North Britain,
Engineer, do hereby declare the nature of the said Invention for "IMPROVE-
MENTS IN THE ARRANGEMENT OR CONSTRUCTION OF STEAM ENGINES AND BOILERS,"
to be as follows, that is to say :-
The improvements comprehended in this Invention are more particularly
designed with the view of obtaining an increased advantage from the use of
steam, of what is generally considered a "high pressure," that is to say, of a
pressure of twenty pounds or upwards to the square inch above the atmo-
sphere, but they are also applicable where steam of "low pressure" is used.
The portion of the Invention relating to steam engines is more particularly
applicable to the class of "double cylinder expansive engines," in which the
steam works in two cylinders before reaching the condenser. The second
cylinder is usually much larger than the first, but according to the present
Invention two cylinders are used instead of such second large one, so that
there are three cylinders in all in the set, and it is preferred to make all three

page_text: of the same size, although they may be of different sizes, if desired. The three
cylinders are placed in a line, and the steam is first admitted to the central
one, the piston of which is connected to its own special crank on the main
shaft. The steam on leaving the central cylinder works simultaneously in the
two other cylinders, a portion of it entering each of them, and finally passes
to the condenser. The pistons of the two outer cylinders are connected to
cranks on the main shaft, placed diametrically opposite to the crank of the
central cylinder, and the direction of the central piston's motion being always
opposite to that of the side piston's, the thrusts or strains on the crank shaft.
bearings are thus opposed, and more or less neutralised. In engines where
no fly wheel is used, such as marine engines, two or more sets of three
cylinders, such as have been described, may be used; the sets of cranks con-
nected with the different sets of cylinders being placed at different angles in
the usual way.
In carrying out the improvements in steam boilers according to one modi-
fication, the boiler is composed of, say, four tubes or tubular vessels of about
two feet in diameter, for example, the lower ends of which are arranged
in a diametrical line across a circular furnace; one tube rises vertically
upwards from the centre of the furnace, and constitutes the axis of a series
of spirals or helices formed by the other tubes. The two outer tubes after
rising vertically for a short distance are curved or coiled round at the dis-
tance of two feet from the central tube, so as to form a two-threaded
spiral or helix, the adjacent convolutions of which nearly or quite touch each
other. The fourth tube is curved or coiled round in the annular space between
the central tube and the outer tubes, so as to leave a space of about two feet
between its convolutions, such space forming a spirally or helically shaped
flue for the passage of the gases from the furnace. The upper ends of the
tubes may be connected to a steam chamber, or any convenient arrangement
may be adopted for collecting and conveying away the steam generated in the
tubes. The lower part of the furnace may be enclosed by a cylindrical water
space, which may be either closed and communicating with the tubes, or open
and acting as a cistern for partially heating the feed water before it is intro-
duced into the boiler. The details and proportions of the improved boiler
may be modified in various ways, but the essential feature in this part of the
Invention is the employment in the construction of steam boilers of a number
of tubular vessels of small diameter as compared with ordinary boilers arranged
spirally or helically in such a way as to form an enclosed spiral or helical flue
or passage for the furnace gases.

page_text: :
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said John Elder in the Great Seal Patent Office on the 28th
July 1858..
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
ELDER, of Glasgow, in the County of Lanark, North Britain, Engineer, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-ninth day of January, in the year of our
Lord One thousand eight hundred and fifty-eight, in the twenty-first year of
Her reign, did, for Herself, Her heirs and successors, give and grant unto me,
the said John Elder, Her special licence, that I, the said John Elder, my
executors, administrators, and assigns, or such others as I, the said John
Elder, 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 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 ARRANGE-
MENT OR CONSTRUCTION OF STEAM ENGINES AND BOILERS," upon the condition,
amongst others, that I, the said John Elder, my executors or administrators,
by an instrument in writing under my, or their, or one of their hands and seals,
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 John Elder 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
in writing, reference being had to the Drawings hereunto attached, and to
the letters and figures marked thereon, that is to say:-
My said Invention comprehends improvements which are more particularly
designed with the view of obtaining an increased advantage from the use of
steam of what is generally considered a "high pressure," that is to say, of a
pressure of twenty pounds or upwards to the square inch above the atmosphere,
but they are also applicable where steam of "low pressure" is used. The
portion of the Invention relating to steam engines is applicable to the class of
"double-cylinder expansive engines," in which, as commonly constructed, the
steam works in two cylinders before reaching the condenser. The second
cylinder is usually much larger than the first, but according to the present
Invention two cylinders are used instead of such second large one; so that

page_text: there are three cylinders in all in the set.
The three cylinders are placed in
a line, and the steam is first admitted to the central one, the piston of which
is connected to its own special crank on the main shaft. The steam on
leaving the central cylinder, works simultaneously in the two other cylinders,
a portion of it entering each of them and finally passes to the condenser. The
pistons of the two outer cylinders are connected to cranks on the main shaft
placed diametrically opposite to the crank of the central cylinder, and the
direction of the central piston's motion being always opposite to that of the
two side pistons, the thrusts or strains on the crank-shaft bearings are thus
opposed and more or less neutralised. In engines where no fly wheel is used,
such as marine engines, two or more sets of three cylinders, such as have been
described, may be used, the sets of cranks connected with the different sets of
cylinders being placed at different angles; or, the two or more sets of cylinders
may be placed in different positions round the shaft and be connected to one
set of cranks.
In carrying out the improvements in steam boilers according to one modi-
fication, the boiler is composed of a series of, say, four tubes or tubular
vessels of about two feet in diameter, for example, the lower ends of which
are arranged in a diametrical line across a circular furnace; one tube rises
vertically upwards from the centre of the furnace, and constitutes the
axis of a series of spirals or helices formed by the other tubes.
. The
two outer tubes after rising vertically for a short distance, are curved or
coiled round at the distance of two feet from the central tube, so as to form a
two-threaded spiral or helix, the adjacent convolutions of which nearly or
quite touch each other. The fourth tube is curved or coiled round in the
annular space between the central tube and the outer tubes, so as to leave a
space of about two feet between its convolutions, such space forming a spirally
or helically-shaped flue for the passage of the gases from the furnace. The
upper ends of the tubes may be connected to a steam chamber, or any convenient
arrangement may be adopted for collecting and conveying away the steam
generated in the tubes. The lower part of the furnace may be enclosed by a
cylindrical water space, which may be either closed and communicate with the
tubes, or open and act as a cistern for partially heating the feed water before
it is introduced into the boiler. The details and proportions of the improved
boiler may be modified in various ways, but the essential feature of this part
of the Invention is the employment in the construction of steam boilers of a
number of tubular vessels of small diameter as compared with ordinary boilers,
arranged spirally or helically in such a way as to form an enclosed spiral or
helical flue or passage for the furnace gases.

page_text: And in order that my said Invention may be properly understood and
carried into effect, I have delineated upon six Sheets of explanatory Drawings
hereunto appended, and shall now proceed to particularly describe certain
examples of the application thereof. Ou Sheets 1, 2, 3, and 4 of the
Drawings are represented various views of the improved engines as arranged
to drive paddle wheels; on Sheet 5. are represented two views of the improved
engines as arranged to drive a screw propeller; and on Sheet 6 are represented
various modifications of the improved boiler.
Figure 1, Sheet 1, is a side elevation; Figure 2, Sheet 2, is a plan; and
Figure 3, Sheet 3, is an end elevation (partially sectioned by different planes)
of the paddle engines; Figure 4, Sheet 4, is a section through their axes of
one set of three cylinders; and Figure 5, Sheet 1, is a detached elevation of a
detail appertaining to the valve gearing. These engines consist of two sets of
three cylinders, each connected to one set of cranks, A, B, B, these cranks being
shown in vertical positions in Figures 1 and 2, and in inclined positions in
Figure 3. Each set of cylinders consists of a central "high-pressure" cylinder C,
which receives steam directly from the boiler, and two "expansive" or "low
pressure" cylinders D, D, one on each side of the high-pressure cylinder C, and
worked by the steam after it has operated in such high-pressure cylinder,.
The admission of the steam into the high-pressure cylinder C is governed by a
simple induction valve E, capable of being set to cut off the steam at any part
of the stroke, and working in a valve chest on the upper side of the cylinder,
as shown in section in Figure 3. After operating in the high-pressure
cylinder C, the steam passes by opposite equal ports into valve chests F,
formed on opposite sides of the high-pressure cylinder C, and between it' and
the "expansive" cylinders D, and crossing these valve chests enters the latter.
cylinders by ports governed by simultaneously worked valves G. The valve
chests F and valves G are shown in section in Figure 4. The valves G are
constructed and worked in such a way as to admit steam alternately at each
end of the "expansive" cylinders 'D, D, and to form communications between
the ports opposite to those receiving steam and the corresponding exhaust
ports H, communicating with the condenser. The cranks B, B, to which the
pistons of the "expansive" cylinders D, D, are connected, are diametrically
opposite on the shaft to the crank A, to which the piston of the high-pressure
cylinder C is connected, from which arrangement it follows that the strains on
the shaft bearings due to the two "expansive" cylinders D, D, are equivalent
to a single strain applied midway between the two cranks B, B, and therefore
in the same plane (transverse to the shaft) as the opposite strain on the shaft
bearings due to the high-pressure cylinder C, so that the resultant strain on

page_text: the shaft bearings due to all three cylinders D, C, D, is reduced to an amount
proportional or nearly so to the difference between the strain of the high-pres-
sure cylinder C and the combined strain of the two "expansive" cylinders D, D.
In designing the engines, I prefer after the extent or degree of expansion to be
devoloped in them is fixed to make the sizes of the cylinders D, C, D, such
that the combined strain due to the two outer cylinders D, D, may differ as
little as possible from that due to the central cylinder C. When the parts
are in the positions in which they are represented in Figure 4, the high-
pressure cylinder C is receiving steam at the bottom, and the piston is rising
whilst the steam in the top of this cylinder, and which has already operated
in it, is passing in equal portions into the tops of the two "expansive"
cylinders D, D, and forcing down their pistons from beneath, which pistons
the steam is passing into the condenser. On the return stroke fresh steam
enters the top of the high-pressure cylinder C, and that from the bottom
thereof passes in equal portions into the bottoms of the two "expansive"
cylinders D, D, the steam from the tops of these last passing into the
condenser. The condensers of the two sets of cylinders lie in the mid space
directly under the shaft, and there is an air pump at each end constructed
internally as shown in section in Figure 3, and worked by an eccentric on the
shaft. The valves are worked by eccentrics on a secondary shaft I, driven at
the same rate as the main shaft, by means of toothed wheels J. The various
eccentrics, as well as the toothed wheel, carried by the secondary shaft I, are
fitted with keys or feathers lying in grooves in the shaft, which keys or
feathers and grooves, or some of them, are inclined in such a way that a
longitudinal motion of the shaft I causes the positions of the eccentrics to be
altered so as to make the engines reverse. For the purpose of imparting the
requisite longitudinal motion to the shaft I, this shaft is formed with a number.
of collars or rings at or near one end, as shown in Figure 1, which rings are
acted upon by a pinion K upon an inclined shaft connected by bevil wheels
L to a horizontal shaft fitted with a reversing hand wheel M, or in the case
of large engines arranged to be driven by a small donkey engine. (It may
be observed here that the reversing wheel M, and the parts connected there-
with, have been represented in different positions in the different Drawings; it
is, however, preferred to place them as represented in Figure 2.)
Figures 6 and 7, on Sheet 5 of the Drawings, are an end elevation and a
plan of a modification of the improved engines designed for driving the screw.
propeller. In these views several of the minor details are omitted; the
engines, however, consist of two sets of three cylinders each; the central.
cylinders C; C', being the high-pressure ones, or those receiving steam directly.

page_text: from the boiler, whilst the outer cylinders D, D, D', D', are the "expansive"
or low-pressure cylinders, and have their pistons connected to the two outer
cranks B, B, placed diametrically opposite on the shaft to the central crank A,
acted upon by the high-pressure cylinders C, C. As in the engines already
described, the steam is admitted into the high-pressure cylinders C, C¹, by
separate induction valves, and it passes thence by separate ports and valve chests
to the "expansive" cylinders D, D, D', D', and finally to the condensers by
exhaust ports in the same valve chests.
ד'
:
In order that the class of engines to which this portion of my Invention
refers, may in practice be efficiently and economically worked, I would re-
commend that spaces or jackets for steam be formed, not only round the sides
of the cylinders, but also in their top and bottom covers, as shown in the
Drawings, and more particularly in Figures 3 and 4.
}
Figure 1, Sheet 6 of the Drawings, is a vertical section, and Figure 2 is a
horizontal section taken a little above the furnace bars, of one modification of
steam boiler constructed according to the second portion of my Invention.
This boiler consists of four tubes a, b, c, d, of circular section, whose lower ends
are arranged as shown in the plan in Figure 2, in a diametrical line across a
circular furnace e. One tube a, placed in the centre of the furnace, rises
vertically upwards. The two outer tubes b, c, after rising vertically to, a level,
a short distance above the furnace bars, are curved or coiled round at a dis-
tance from the central tube a, equal to the diameter of the fourth tube d, so as
to form a two-threaded spiral or helix, the adjacent.convolutions of which are
in contact. The fourth tube d is curved or coiled round in the annular space
between the central tube a and the outer tubes b, c, in such a way as to leave
a space about equal to its diameter between its convolutions, such space
forming a spirally or helically-shaped flue for the passage of the gases from
the furnace to the chimney f. The central tube a is carried up a considerable
distance inside the chimney f, its upper end answering in place of a steam
dome, and being in communication with the upper ends of the tubes b, c, and
d, by the pipes g, so as to receive the steam generated in these last, whilst the
steam in it becomes well dried. In this modification the steam is taken off
by a pipe h, which passes down the centre of the tube a, and feed water is
admitted into all the tubes a, b, c, d, by branches i, from the feed pipe j. The
furnace is enclosed by a cylindrical water space k, extending also beneath the
bottom, which, in this instance, serves to heat the feed water prior to its being
pumped through the pipes l, j, into the boiler. In each of the tubes a, b, c, d,
there is a pipe m, having an open mouth at its upper end, a little below the
water surface, and a turned-up mouth at its lower end, which is a short

page_text: distance, from the bottom of the tube; the object of this pipe m being to
occasion a current in the water in the tube, and thereby assist the rising of
any steam formed in the lower part of the tube.
Figure 3, Sheet 6 of the Drawings, is a vertical section, and Figure 4 is a
horizontal section taken a little above the furnace bars, of a second modification
of my improved boiler. In this boiler there are only three tubes a, b, d,
instead of four, the central tube a rising up vertically, whilst another b, after
rising vertically to a point a short distance above the furnace bars e, is curved
or coiled round spirally or helically at a short distance from the central tube a,
and the third tube d is curved or coiled round spirally or helically from the
same level as the tube b, in contact with this last and with the central tube a,
in such a way as to form a spirally or helically-shaped flue for the passage of
the gases from the furnace to the chimney f.
Figure 5, Sheet 6 of the Drawings, is a vertical section, and Figure 6 is a
horizontal-section, of a third modification of my improvod boiler, in which five
tubes a, b, c, d, d¹, are used. This modification differs from that represented
in Figures 1 and 2, in having two tubes d, d', curved or coiled round between
the central tube a and the outer tubes b, c.
Figure 7, Sheet 6 of the Drawings, is a vertical section, and Figure 8 is a
horizontal section, of a fourth modification of my improved boiler, in which
three tubes a, b, d, are used. In this instance the central tube a is of circular
section, but the tubes b, d, are in section, semicircular on one side and
rectangular on the other. The tube 6 is curved or coiled round at a short
distance from the central tube a, and the tube d is curved or coiled round in
contact with the central tube a, but it is as much greater in width as
measured from the central tube outwards as makes it flush externally with the
tube b. In this instance the tubes are represented as covered by an external
cylindrical casing; and the steam pipe h is represented as passing down
between the upper part of the central tube a and the side of the chimney f,
ultimately passing out through the side of the chimney.
Figure 9; Sheet 6 of the Drawings, is a vertical section, and Figure 10 is a
borizontal section, of a fifth modification of my improved boiler. In this
instance there are five tubes a, b, c, d, d¹, of sections, similar to those repre-
sented in Figure 7. The outside tubes b, c, as well as the inner ones d, d', in
contact with the central tube a, are alternately of lesser and greater width as
measured outwards from the central tube, being all curved or coiled round in
such a way as to form between them a spirally or helically shaped flue for the
passage of the gases from the furnace e to the chimney f. The outer tubes
b, c, are represented as formed by attaching curved plates to
the interior of a

page_text: cylindrical shell n, and the attachment may be effected either by means of
angle iron, as shown on an enlarged scale in Figure 11, or by means of flanges
formed upon the plates, as shown in Figure 12. The inner tubes d, d, may
be attached to the central vertical tube a in similar ways. The steam pipe h,
Figure 9, is arranged in the same way as in Figure 7.
The boilers represented on Sheet 6 of the Drawings are all shown as
having current pipes m, as described in respect of Figures 1 and 2; these
current pipes may, however, if desired, be applied externally to the tubes
a, b, c, d, d', communicating with these tubes at their upper and lower ends.
The same arrangement of feed water heating cistern k is also represented as
applied to the several modifications of boiler to encase the furnace e; .these
cisterns may, however, form parts of the boilers themselves, or. the furnaces
may be encased differently. The spiral portion of the boilers represented in
Figures 1 to 6 (Sheet 6) may or may not be encased in cylindrical shells.
In Figures 2, 4, 6, and 8 the furnaces are represented with only portions of
their fire bars in place. These furnaces may be arranged in a variety of ways,
of which one or two examples are given in the Drawings. I would also
observe, that although in all the modifications of boiler represented on Sheet 6
of the Drawings, the lower portions of the tubes are shown as arranged in
a line crossing the furnace diametrically, other arrangements may be adopted;
thus the spiral or helical convolutions may spring from three or more points.
round the circle of the furnace, and instead of only one spiral flue being
formed, as shown in the Drawings, the tubes may be arranged so as to con-
tain two or more such flues. The central vertical tube may also in some
cases be dispensed with, a spiral or helical flue or flues being made entirely by
means of coiled tubes. It is preferred to arrange the spiral or helical coils
round a vertical axis, but the axis may be more or less inclined, provided the
parts are so arranged that steam cannot lodge in parts of the coils below the
general surface of the water.
Having now particularly described my said Invention, and the manner in
which the same is or may be used or carried into effect, I must observe that I
do not restrict myself to the precise details which I have herein-before
described or delineated, and that I do not claim to have invented every sepa-
rate detail herein-before described or delineated; but what I believe to be
novel and original, and claim as the Invention secured to me by the herein-
before in part recited Letters Patent, is,―
First, the general arrangement and combination of the parts of steam
engines and boilers herein-before described.
Second, the arrangement or construction of steam engines comprehending

page_text: one or more sets of cylinders, each set consisting of three cylinders, the central
one of which receives steam direct from the boiler, and has its piston connected
to a crank between and diametrically opposite on the main shaft to two cranks
connected to the pistons of the two outer cylinders, which last simultaneously
receive the steam after it has operated in the central cylinder, as herein-before
described.
Third, the arrangement or construction of steam boilers, wherein tubular
vessels of comparatively small diameter are arranged spirally or helically, in
such a way as to form an enclosed spiral or helical flue or passage for the
furnace gases, as herein-before described.
In witness whereof, I, the said John Elder, have hereunto set my hand
and seal, this Twenty-sixth day of July, in the year of our Lord
One thousand eight hundred and fifty-eight.
Witness,
EDMUND HUNT,
Patent Agent, &c.,
28, St. Enoch Square,
Glasgow.
JOHN ELDER. (L.S.)