IMPROVEMENTS IN STEAM ENGINES AND BOILERS
Year: 1860

page_text: LETTERS PATENT to John Martin Rowan, of Glasgow, in the County of
Lanark, and Thomas Rogers Horton, of Birmingham, in the County of
Warwick, both Engineers, for the Invention of "IMPROVEMENTS IN STEAM
ENGINES AND BOILERS."
PROVISIONAL SPECIFICATION left by the said John Martin Rowan and
Thomas Rogers Horton at the Office of the Commissioners of Patents,
with their Petition, on the 8th February 1860.
We, JOHN MARTIN ROWAN, of Glasgow, in the County of Lanark, and
THOMAS ROGERS HORTON, of Birmingham, in the County of Warwick, both
Engineers, do hereby declare the nature of the said Invention of "IMPROVE.
MENTS IN STEAM ENGINES AND BOILERS," to be as follows, that is to say :-
This Invention relates to various improvements in the arrangement and
construction of the parts of steam engines and boilers, and comprises modifi-
cations of some of the improvements described in the Specification of Letters
Patent for. "Improvements in Steam Engines and Boilers," granted to the
present applicants, under date the 19th April 1858 (No. 856), together, with
additional improvements, the objects being generally to economise. space and
[Price 8d.]

page_text: fuel, and to render the engine and boiler capable of safely developing an
increased power.
The improvements in engines are designed for working on the high and
low pressure system, and in one arrangement, embodying a modification of
these improvements, the piston of each low-pressure cylinder is formed with
trunks or plungers, working as single-acting pistons in high-pressure
cylinders annexed to the ends of the low-pressure cylinder.
In a second modification, a high-pressure cylinder is placed within each
low-pressure cylinder, the piston of the latter being formed with a closed
trunk working upon or over the high-pressure cylinder, and in a trunk or
recess in the end of the low-pressure cylinder.
In a third modification, a high-pressure cylinder is placed against or
partly sunk into the cover of each low-pressure cylinder, and from these
cylinders three piston rods emerge by external stuffing boxes, one from the
high-pressure piston and two from the low-pressure piston, the three being
connected by a cross head, whilst a forked connecting rod is jointed upon
the two low-pressure piston rods.
In a fourth modification, a pair of cylinders arranged slightly apart are
placed against the cover of a single cylinder. The three piston rods pass
out through external stuffing boxes, and are connected to one connecting
rod. The single cylinder may be low pressure and the pair of cylinders
high pressure, or vice versa. Instead of the pair of cylinders one annular
cylinder may be used.
In a fifth modification, a high-pressure cylinder is placed against the bottom
or back cover of a single-trunk cylinder, the rod of the high-pressure piston
passing through a metallic packing in the cover of the low-pressure piston; or
the partition between the cylinders may be dispensed with, in which case the
steam, after acting on the back of the high-pressure piston, acts on the front of
the low-pressure piston, and then in the space between the two pistons.
Another portion of the improvements in engines has reference to the valves
for combined high and low-pressure cylinders, and comprises a modification
of combined valves and casing, in which the valve slides for the high and
low-pressure cylinders respectively are both fixed upon one rod. A partition
divides the casing between the slides, and a metallic packing is applied to
the aperture therein for the valve rod; separate internal spaces are also pro-
vided in the combined casing for the introduction of steam to heat the partly
used steam passing from the high-pressure to the low-pressure cylinder.
In another modification of combined valves and casing, there is a separate

page_text: valve slide for each end of the high-pressure cylinder, both being on one
rod, and a separate valve slide for each end of the low-pressure cylinder;
the two latter being on a second rod which passes through a metallic
packing in a partition between them. Separate internal spaces are provided
for steam to heat the partly used steam passing from the high-pressure to
the low-pressure cylinder.
In applying modifications of the surface condenser described in the Specifi-
cation herein-before referred to, one or more rotatory or other agitators may
be applied in various positions; the same may also be applied to surface
refrigerators. A plate may also be placed in the bottom of the condenser or
refrigerator for directing the course of the condensing or cooling medium.
A further improvement in surface condensers and refrigerators, the tubes
of which are packed with caoutchouc, consists in lining the caoutchouc,
where it bears upon the tube, with linen or other material having com-
paratively little frictional hold on the tube.
The present improvements in boilers consist principally of modifications
of the "compound subdivided" boilers described in the Specification
herein-before referred to.
"
In one of such improved modifications, the arrangements for causing the
serpentine" or return movements of the fire gases is dispensed with,
and these gases traverse the whole of the external flue spaces and of the
internal tubular spaces in one general direction.
This class of boiler may be composed or built up of rectangular flat
leaves or sections, with hollow subdividing partitions, and with or without
flue tubes, or it may consist of cylindrical or curved sections arranged
concentrically, or otherwise; also with hollow subdiving partitions, and
with or without flue tubes.
In another modification of compound subdivided boiler, flat rectangular
leaves or sections are placed at right angles to each other in plan, so as to
enclose the grate or furnace. There are no leaves or sections directly over
the fire. but the fire gases passing up the inside of the rectangular case
formed by the leaves or sections are next directed down tubes traversing these
leaves or sections. This species of hollow-sided casing may be constructed
as a single section or boiler, and of a rectangular or other form in plan, being
however subdivided by hollow vertical partitions. Instead of the hollow flat
subdividing partitions, the sides of the subdivisions may be bent or curved in,
so as to give a circular or curved transverse section to the water spaces. One
or more of the leaves or sections of these boilers may be carried above the
general level, their upper parts constituting stean spaces,

page_text: In another modification of compound subdivided boiler, the leaves or sec-
tions consist each of a hollow or tubular frame, which is crossed vertically or
horizontally by tubes having the water inside them, whilst the fire gases play
upon them externally These tubes are ferruled through apertures in the
outer plates of the frames, the apertures being afterwards filled by cup-
shaped plugs, which are themselves fixed by means of ferrules.
According to a further modification, these water tubes may be traversed
by inner flue tubes. The sections or leaves may be of various forms.
The Invention further comprehends improved apparatus for regulating the
feed of steam boilers, more particularly when the same water is used over
and over again in the boiler, and also improved apparatus for adjusting the
flue or ash-pit dampers of steam boilers. The improved feed regulator
consists of a float cock in connection with the cistern, from which the feed
water is pumped into the boiler. On the water in the cistern becoming
too low, the float opens the cock, which allows the water pumped to pass
back into the cistern instead of into the boiler. The pump can thus be
kept constantly working, without the possibility of pumping air into the
boiler. In the improved apparatus for adjusting the dampers, the damper
lever or chain is connected to a rod having fast on it two pistons of different
areas, working in a suitably shaped cylinder or chamber. The outer side of
the small piston is always exposed to the boiler pressure, whilst the opposite
side of the large piston is only acted upon by the steam when its pressure
rises beyond a predetermined amount, and when it raises a valve loaded
to that amount, which valve admits it to the large piston.
In consequence of the differenceofarea a movement then takes place which
closes the damper or dampers. On the boiler pressure becoming diminished,
the loaded valve closes the inlet of steam to the large piston and opens an
outlet for the steam beneath it, whereupon the steam acting on the small
piston causes a movement which opens the damper or dampers. Instead of
the small steam piston the rod of the large piston may be arranged to lift a
series of weights in succession, each weight being lifted on a corresponding
increase of pressure taking place, and the damper or dampers being corre-
spondingly closed. In their extreme positions the pistons and valves fit
against seats, to prevent leakage. In some cases the loaded valve by which
steam is admitted to the large piston may be dispensed with.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said John Martin Rowan and Thomas Rogers Horton, in the
Great Seal Patent Office on the 8th August 1860.
TO ALL TO WHOM THESE PRESENTS SHALL COME, we, JOHN
MARTIN ROWAN, of Glasgow, in the County of Lanark, and THOMAS ROGERS
HORTON, of Birmingham, in the County of Warwick, both Engineers, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Eighth day of February, in the year of our Lord
One thousand eight hundred and sixty, in the twenty-third year of Hor
reign, did, for Herself, Her heirs and successors, give and grant unto us
the said John Martin Rowan and Thomas Rogers Horton, Her special
licence that we, the said John Martin Rowan and Thomas Rogers Horton,
our executors, administrators, and assigns, or such others as we, the
said John Martin Rowan and Thomas Rogers Horton, our 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 STEAM ENGINES AND
BOILERS," upon the condition (amongst others) that we, the said John Martin
Rowan and Thomas Rogers Horton, our executors or administrators, by an
instrument in writing under our, 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 saine was to be performed, and cause the same to
be filed in the Great Seal Patent Office within six calendar mouths next and
immediately after the date of the said Lotters Patent.
NOW KNOW YE, that we, the said John Martin Rowan and Thomas
Rogers Horton, do hereby declare the nature of our 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 accompanying Drawings, and to the letters and figures marked
thereon, that is to say:-
Our said Invention relates to various improvements in the arrangement and,
construction of the parts of steam engiues and boilers, and comprises modifi-
cations of some of the improvements described in the Specificationof Letters
Patent for "Improvements in Steam Engines and Boilers," granted to us, the

page_text: said John Martin Rowan and Thomas Rogers Horton, under date the 19th
April 1858 (No. 856), together with additional improvements; the object
being generally to economise space and fuel, and to render the engine and
boiler capable of safely developing an increased power.
And in order that our said Invention may be properly understood and
carried into effect, we have hereunto appended three Sheets of explanatory
Drawings, to which we shall refer in particularly describing our improve-
ments, as follows:-
The improvements in engines are designed for working on the high and low-
pressure system; and in one arrangement embodying a modification of these
improvements, the piston of each low-pressure cylinder is formed with trunks
or plungers, working as single-acting pistons in high-pressure cylinders
annexed to the ends of the low-pressure cylinder. A pair of engines thus
constructed is represented in section and side elevation in Figure 1, and in
end elevation in Figure 2, Sheet 1 of the Drawings.
The low-pressure piston A is formed with or has attached to its trunks b, b,
which have packing rings at their ends, each working in a high-pressure
cylinder c. The power is transmitted by rods D, 1), fixed to the low-pressure
piston A, and passing out at opposite sides of one of the nigh-pressure
cylinders c, being fitted with side blocks working between guides at the
sides of this cylinder c,and having a forked connecting rod E jointed to them.
Figure (Sheet 1) is an end elevation, Figure 4 is a plan, partly in
section, and Figure 5 is a vertical section, of a pair of marine engines in which
the arrangement of the high-pressure and low-pressure cylinders is slightly
modified from that just described. The low-pressure piston A is formed with a
trunk b, working in a high-pressure cylinder c, against one end of the low-
pressure cylinder a, whilst the inside of the trunk is contrived to act as
cylinder for the plunger or trunk f, fixed to the front cover of the low-pressure
cylinder a. The power is transmitted, as in the previous exemple, by two
rods D), fixed to the low-pressure piston A. Figure 6 (Sheet 1) is a longi-
tudinal section of high-pressure cylinder c, and low-pressure cylinder a,
differing in arrangement from that represented in Figure 4, only in the
hollow trunk bhaving a return trunk or plunger b', working in a cylinder c¹,
fixed to the inside of the front cover of the low-pressure cylinder a, these
parts being as it were sunk in, instead of projecting as in the arrangement
represented in Figure 1.
In a fourth modification, represented in section in Figure 7 (Sheet 1)
a high-pressure cylinder'c, is placed against or partly sunk into the cover

page_text: of the low-pressure cylinder a, and from these cylinders throe piston rods
emerge by external stuffing boxes; one d, from the high-pressure piston B
and two D, D, from the low-pressure piston A, the three being connected
by a cross head, whilst a forked connecting rod (such as is shown in
Figure 1, at E) is jointed upon the two low-pressure piston rods D, D.
In a fifth modification, represented in section in Figure 8 (Sheet 1), a
high-pressure cylinder C is placed within the low-pressure cylinder a, tho
piston A of the latter being formed with a closed trunk working upon or
over the high-pressure cylinder C, and in a trunk or recess in the end of
the low-pressure cylinder a. The arrangement shown in Figure 6 is also
to some extent according to this modification.
In a sixth modification, a pair of cylinders arranged slightly apart are
placed against the cover of a single cylinder. The three piston rods pass out
through external stuffing boxes, and are connected to one connecting rod;
the block upon which the connecting rod is jointed being upon the central
piston rod, and working between the pair of cylinders. The single cylinder
may be low-pressure, and the pair of cylinders high-pressure, or vice versa.
Instead of the pair of cylinders one anuular cylinder may be used.
In a seventh modification, represented in section in Figure 9 (Sheet 1), a
high-pressure cylinder C is placed against the bottom or back cover of a
single trunk low-pressure cylinder a, the rod d of the high-pressure piston B
passing through a metallic packing Gin the cover to the low-pressure piston A;
this rod d may be passed through the piston A, and be formed to receive the
brasses for the connecting rod joint, as shown in the Figure. In some cases
the partition and packing G between the cylinders C, a, may be dispensed
with, and the steam may be directed to act first on the back of the high-
pressure piston B, then on the front of the low-pressure piston A, and finally
in the space between the two pistons.
Another portion of the improvements in engines has reference to the valves
for combined high and low pressure cylinders, and comprises a niodification of
combined valves and casing, in which the valve slides for the high and low
pressure cylinders respectively are both fixed upon one rod. Figures 10, 11,
12, and 13 (Sheet 1), are separate views explanatory of this arrangement,
which is also shown in section in Figure 1. Figure 10 is a vertical section of
the casting introduced between the two double sets of valve faces, the section
being on the line 10-10, Figure 15; Figure 11 is an elevation of the central
casting; Figure 12 is a vertical section of it on the line 12--12 in Figures 10
and 11; and Figure 13 is a vertical section of it on the line 13-13 in

page_text: Figure 11. The valve slides H, L, of the high and low pressure cylinders
respectively are fixed upon one rod I, but a partition J divides the casing
between the slides,and a metallic packing is applied to the aperture therein
for the valve rod. In Figure 1 are shown the ports 1, 2, leading to the
opposite ends of the high-pressure cylinder (or what in this case is equivalent
thereto) and the high-pressure exhaust port or passage 3 (the continuation
of which is seen in Figures 10, 11, and 13), leading to the back of the low-
pressure valve L. Below these parts are the low-pressure admission and
exhaust ports 4, 5, and 6, the coutinuation of the last being seen in Figures 10
and 11. Separate internal spaces 7 are also provided in the combined
casing for the introduction of steam to heat the partly used steam passing
from the high-pressure to the low-pressure cylinder.
In another modification of combined valves and casing, represented in
horizontal and vertical section in Figures 14 and 15 (Sheet 1), there is a
separate valve slide h, h, for each end of the high-pressure cylinder C, both
being on one rod i, aud a separate valve slide 1, 1, for each end of the low-
pressure cylinder a, the two latter being on a second rod i,, which passes
through a metallic packing at J in a partition between them. Separate internal
spaces 7 are provided, as in the other modification, for steam to heat the
partly used steam passing from the high-pressure to the low-pressure cylinder.
In modifications of the surface condenser described in the Specification
herein-before referred to, one or more rotatory or other mechanical agitators
may be applied in various positions. The same may also be applied to surface
refrigerators, that is, to apparatus for cooling water used in condensing the
steam of steam engines by injection. A plate may also be placed in the
bottom of the condenser or refrigerator for directing the course of the con-
densing or cooling medium. A further improvement in surface condensers
and refrigerators, the tubes of which are packed with caoutchouc, consists
in lining the caoutchouc where it bears upon the tube with linen or other
material having comparatively little frictional hold on the tube.
دو
The present improvements in boilers cousist principally of modifications of
the "compound subdivided" boilers described in the Specification herein-
before referred to. In one of such modifications the arrangements for causing
the "serpentine or return movements of the fire gases is dispensed with,
and these gases traverse the whole of the external flue spaces and of the
internal tubular spaces in one general direction. In other modifications,
however, the provisions for the serpentine course of the gases is retained. This
class of boiler may be composed or built up of rectangular flat leaves or

page_text: sections with hollow subdividing partitions, and with or without flue tubes,
or it may consist of cylindrical or curved sections arranged concentrically or
otherwise, also with hollow subdividing partitions, and with or without flue
tubes.
In one modification of these compound subdivided boilers, flat rectangular
leaves or sections are placed at right angles to each other in plan, so as to
enclose the grate or furnace, and the fire gases passing up the inside of the
rectangular case are next directed down tubes traversing these leaves or
sectious. This species of hollow sided casing may be constructed as a single
section or boiler, and of a rectangular or other form in plan, being however,
in all cases subdivided by hollow vertical partitions. Instead of the hollow
flat subdividing partitions the sides of the subdivisional water spaces may be
bent or curved in, and in some cases one or more of the leaves or sections of
the boiler may be carried above the general level, their upper parts con-
stituting steam spaces.
In some modifications of the compound subdivided boiler, the leaves or
sections consist each of a hollow or tubular frame, which is crossed vertically
or horizontally by tubes having the water inside them, whilst the fire gases
play upon them externally. These water tubes may be traversed by inner
flue tubes, and the sections, leaves, or frames may be of various forms.
On Sheets 2 and 3 of the accompanying Drawings there are represented
various examples of the numerous modifications of boiler comprised under the
foregoing general description. Figure 16 is an elevation, one half in vertical
section, of a cylindrical boiler; Figure 17 is a plan, one half with the external
casing removed and Figure 18 is a horizontal section taken at the lines
18-18 in Figure 16. This boiler is made up of a number of concentric
cylindrical sections, each subdivided by hollow partitions. The steam gene-
rated in each section is conveyed by pipes M,as shown in Figures 16 and 17,
to a central cylindrical steam chest N. The furnace space is formed by the
increased downward extension of the outer cylindrical section, and the fire
gases are made to proceed in the directions indicated by the arrows in Figure
16,by stop plates arranged in suitable positions across the spaces between the
water spaces. Figure 19 is a vertical half section, and Figure 20 is a hori-
zontal half section of a boiler differing from that last described in having a flue
cube down each subdivisional water space, except in the case of the external
section, which descends below and surrounds the furnace space. In this
example the gases pass upwards through the tubes and between all the inner
subdivisional water spaces, but are caused to descend along the outer section.

page_text: before passing off up the funnel as indicated by the arrows. Figure 22 is a
vertical half section,and Figure 23 is a horizontal half section, of a cylindrical
boiler, in whichtheinner portion consists of two concentric sections, each section
being composed of upper and lower hollow ring-shaped frames connected by
vertical water tubes. The outer section consists of a cylindrical water space
subdivided by hollow radial or transverse partitions. The fire gases pass as
indicated by the arrows, first up round the lower ring-shaped frames, then
across the water tubes, next into the hollow partitions in the outer section,
and through the upper parts of these partitions,and finally down the outside of
the outer section and up to the funnel. Figure 24 is a horizontal half section
of a boiler which is square in plan, and consists of rectangular hollow-sided
casings arranged one within the other, and each subdivided by flat hollow
partitions. Figure 25 is a vertical half section, and Figure 26 is a horizon-
tal half section, of a boiler, comprising four sections one within the other in
addition to a centre steam chest N. The two inner sections are above the
*fire and consist each of upper and lower square hollow frames connected by
vertical water tubes. The two outer sections or leaves extend down round
the furnace space, and are subdivided by hollow partitions. The fire gases,
after passing amongst the vertical water tubes, proceed through the hollow
partitionsof thethird section and pass downwards between the third and outer
section, returning upwards by flue tubes traversing the two outer sections, as
indicated by the arrows. Figure 27 is a vertical half section, and Figure 28
is a horizontal half section, of a boiler, differing from the preceding in being
cylindrical, and in having the subdivisional water spaces of the two outer
sections of circular, instead of rectangular sectiou whilst a single flue tube
traverses each subdivisional space. Figures 29 to 32 represent another
modification of our improved boilers, Figure 29 being a longitudinal vertical
section as along the line 29-29 in Figure 31; whilst Figure 30 is a side
elevation of the boiler with the outer casing removed. Figure 31 is a bori-
zontal section as along the line 31-31 in Figure 32 and Figure 32 is a
vertical section as at the lines 32-32 in Figure 30. This boiler consists of
six vertical leaves or sections arranged longitudinally, the two outer sections
being plain, except that they are subdivided by hollow vertical partitions, the
outer sides of which are closed. The four inner sections consist of rectangular
hollow frames shaped to leave a furnace space at one end, whilst the upper
and lower horizontal partsof the frames are connected by vertical water tubes.
The several sections communicate with steam chests N, by pipes M; the
pipes being formed with bent discharge mouths, to direct any water thrown up

page_text: with the steam towards one end of the steam' chest, which end is made lower
than the other, and from which end there are pipes and branches P to convey
the water back into the bottom of the boiler. The fire gases may be made
to take various courses by introducing suitable stop or directing plates.
Figures 33 to 36 (Sheet 3) represent a modification of boiler differing some-
what from that last described: Figure 33 is a front elevation, one half in
vertical section, as at the line 33-33, Figure 34;, and Figure 34 is a vertical
section at right angles to Figure 33; Figure 35 is a half plan, and Figure 36
is a horizontal half section, as at the line 36-36 in Figure 33.. This boiler
is composed of a number of hollow frame sections made to partly enclose the
furnace, as shown best in Figure 34, an upper open part of each frame being
crossed by vertical water tubes. At each side there are two vertical hollow
partitioned sections traversed by flue tubes, whilst in the centre between the
two furnaces there is a single vertical hollow partitioned section or water
space not traversed by tubes: The direction of the fire gases is indicated by
arrows, these gases first passing up amongst the water tubes, then laterally,
and down between the two outer sections, and finally up through tubes
traversing these sections. The direction of tlie gases may however be varied,
whilst the arrangementof the steain chestsand return pipesfor the water thrown
up into them will be clearly understood from the Drawings. Amongst various
obvious modifications of which the arrangements of boiler delineated and
described are susceptible, it may be stated that water tube frames may be
substituted for the outer sections shown in Figures 22, 23, 25 to 29,
and 31 to 34.
Figures 37 to 43 (Sheet 3) are detail views showing on an enlarged scale,
modes of forming the subdivided sections orleaves, of which some modifications
of our improved boilers are made up. Figure 37 is a side elevation, and
Figure 38 is a vertical section, both Figures with the middle parts broken
away, of a portion of a section, Figure 39 being a horizontal section. In
this example the section is formed by taking tubes Q, and opening and
welding: their ends together, flat pieces or strips R.being rivetted in at top
and bottom: These subdivisions may be without flue tubes, as at S, (and as
in Figures 16, 18, and.in the outer section in Figures 19, 20, and 21), or they
may be traversed by a single flue tube as at T, (and as in Figuros 19, 20, 27,
and 28,) or with seven or other number of tubes as at U, (and as in Figure
21). According to the mode of construction shown in Figures 40 to 43,
the halves of two adjacent subdivisions are formed in one piece by shaping
and welding,.and.the whole is built up by rivetting such pieces together,

page_text: and to top and bottom strips R. One or more flue tubes may be passed
through each subdivision or not, as in the preceding case. Figures 44 and
45 are section and edge view of the plug used in forming the tube-frame
sections, such as are shown in Figures 22, 23, 25 to 29, and 31 to 34.
Each tube is passed through a hole in the outer edge plate of the frame,
which hole is filled up by a cup-shaped plug V, this plug being fixed by a
ferrule W, as in fixing the tubes themselves.
The Invention further comprehends improved apparatus for regulating
the feed of steam boilers, more particularly when the same water is used
over and over again in the boiler; and also improved apparatus for adjusting
the flue or ash-pit dampers of steam boilers. The improved feed regulator
consists of a float cock in connection with the cistern from which the feed
water is pumped into the boiler. On the water in the cistern becoming too
low, the float opens the cock, which allows the water pumped to pass back
into the cistern instead of into the boiler. The pump can thus be kept
constantly working without the possibilty of pumping air into the boiler.
In the improved apparatus for adjusting the dampers, a modification of
which is shown in vertical section in Figure 46, (Sheet 3), the damper lever
or chain is connected to a rod a, having fast on it two pistons b, c, of different
areas, working in a suitably shaped cylinder or chamber d. The outer or
upper side of the small piston is always exposed to the boiler pressure,
whilst the opposite side of the large piston is only acted upon by the stoam
when its pressure rises beyond a predetermined amount, and when it raises
a valve e, loaded to that amount, which valve e admits it to the large piston.
In consequence of the difference of area a movement then takes place which
closes the damper or dampers. On the boiler pressure becoming diminished,
the loaded valve e closes the inlet of steam to the large piston, and opens
an outlet for the steam beneath it, whereupon the steam acting on the
small pistor causes a movement which opens the damper or dampers.
Instead of the small steam piston the rod of the large piston may be arranged
to lift a series of weights in succession, each weight being lifted on a cor-
responding increase of pressure taking place, and the damper or dampers
being correspondingly closed. In their extreme positions the pistons and
valves fit against seats to prevent leakage. In some cases the loaded valve
by which steam is admitted to the large piston may be dispensed with.
Having thus particularly described our said Invention, and the manner in
which the same is or may be used or carried into effect, we have to state that
we do not restrict ourselves to the precise details herein-before described or

page_text: delineated, but that what we claim, as the Invention secured to us by the
herein-before in part recited Letters Patent, is-
First, the arranging, combining, or constructing of the parts of steam
engines, substantially as herein-before described.
Second, the herein-before described improvements in surface condensers
and refrigerators.
Third, the arranging, combining, and constructing of compound sub-
divided boilers, substantially as herein-before described.
Fourth, the using of a float cock to regulate the feed to the boilers
where fresh water is used, substantially as herein-before described.
And, fifth, the constructing of apparatus for regulating the dampers of
steam boilers, substantially as herein-before described.
In witness whereof, we, the said John Martin Rowan and Thomas
Rogers Horton, have hereunto set our hands and seals, this Sixth
day of August, in the year of our Lord One thousand eight hundred
and sixty.
JNO. M. ROWAN.
(L.B.)
THOS R. HORTON. (L.S.)