IMPROVEMENTS IN STEAM AND AIR ENGINES, AND FURNACES THEREFOR
Year: 1857

page_text: LETTERS PATENT to Charles Barlow, of the Office for Patents, 89,
Chancery Lane, London, for the Invention of "IMPROVEMENTS IN STEAM
AND AIR ENGINES, AND FURNACES THEREFOR."-A communication.
Sealed the 21st May 1858, and dated the 23rd November 1857.
PROVISIONAL SPECIFICATION left by the said Charles Barlow at the
Office of the Commissioners of Patents, with his Petition, on the
23rd November 1857.
I, CHARLES BARLOW, of the Office for Patents, 89, Chancery Lane, London,
do hereby declare the nature of the said Invention for "IMPROVEMENTS IN
STEAM AND AIR ENGINES, AND FURNACES THEREFOR," a communication from a
foreigner residing abroad, to be as follows:-
The engine has one large cylinder, with a blowing cylinder connected as
now arranged to the beam opposite to the air pump. There are also two
auxiliary high-pressure engines placed alongside the large engine, connected
at right angles, and working two blowing cylinders connected directly to the
piston rods. The boiler is placed in a line with the engine, cr may be varied
in position, and in the central part thereof are numerous horizontal tubes
leading from the furnace to a large horizontal flue in the rear end of the
boiler, in which are arranged superheating tubes, and over the back end of
which stands the chimney, which is fitted with an air-tight valve.
Combustion is produced in a close furnace, the doors shutting tightly, and
the bars being tubes to allow circulation of water through them, and they

page_text: incline upwards at about an angle of 32°, meeting in the centre and forming
a ridge to facilitato spreading the coal. The coal feeder is a tube leading
from the centre of the furnace cover, and extended some two feet above, and
fitted with an air-tight valve toward the lower end, and with a scattering
plate, which resembles a throttle valve, in the lower end, which is rectangular,
and by placing which either vertically or inclined either way, the coal drops
directly down upon or toward either end of the furnace. Air pipes from the
blowing cylinders leads into the ash-pit, and with a branch pipe into the coal
feeder, just below the valve, to supply air to help to consume the gases in the
upper part of the furnace. A compound heater for the feed water is placed
alongside the boiler, on the opposite side from the auxiliary engines.
Combustion is produced in this air-tight furnace, and under a pressure of
fifteen pounds above the atinosphere, & pressure is produced by the blowing
cylinder forcing atmospheric air under the fire, and also through the coal
feeder upon the top of the fire, the gases being also retarded or kept in the
furnace by means of a hanging bridge over the fire.
This bridge and the absence of currents, owing to the pressure of the air,
causes a thorough diffusion of the carbonic oxide, carbon, &c., with the oxygen,
and at a high temperature favorable to combustion, and these gases with
large volumes of nitrogen then pass from the furnace through the tubes of
the boiler to the large flue, where they surround the superheating tubes from
the boiler. They pass at about 400° temperature to the lower end of the
large cylinder, when they are cut off at about stroke, and exhausted at a
temperature of 300° into the compound heater, which heats both the feed
water and the air for the furnace; entire combustion is thus secured, & with
an economical employment of fuel.
The large engine is on the condensing or low-pressure principle, that is, the
steam is admitted to the upper end and the vacuum formed in the usual way,
and the products of combustion or hot air, at a pressure of 15 pounds above
the atmosphere produced by the blowing cylinders, is admitted in the lower
end, the air pressure and vacuum acting upward, being together equal to the
steam pressure acting downward; and the superfluous heat of the air com-
municated to the cylinder on the upward stroke is absolved by the steam on
the downward stroke, and thereby a greater degree of expansion of the steam
produced. Steam passes from the boiler at a pressure of 78 to 90 lbs. to tho
auxiliary engines, where it is cut off at half stroke, and its pressure reduced to
about 40 pounds; it is then exhausted through the superheating pipes into a
large receiver, which may be placed between the boiler and large engine, and
which receiver equalizes the pressure as the auxiliary engines exhaust from

page_text: both ends of their cylinders, while the large engine takes steam only at its
upper end. Such superheated steam passes from the receiver to the upper
end of the cylinder of the large engine, when it is cut off at half stroke,
expanded, and a vacuum formed in the usual way.
This Invention combines the caloric and steam engine without the
objectionable features of the former, & improving the best properties of
the latter. The temperature of the hot air is so reduced that the surface
of the cylinder is.not injured by it, but has a beautiful smooth surface,
and the redundant temperature of the air in the cylinder goes directly to
produce a greater degree of expansion in the steam.
The general character or nature of the Invention consists in using steam
at high-pressure in one engine, and then surcharging it with heat before it
passes to the low-pressure or condensing engine, so that the benefit of the
high-pressure and low-pressure engine inay be made available, and also in
using the air in one end of the cylinder, or separately, after being perfectly
tempered, so that the benefit of condensation and vacuum can be made
available and in the most effective manner; and also in arranging the
superheating surfaces of the boiler, so as to maintain and introduce the
temperature in an engine at such a point that lubrication with oil can be
maintained; also in introducing into the high-pressure engine the use of a
close furnace and superheating pipes to surcharge the steam.
SPECIFICATION filed in pursuance of the conditions of the Letters Patent
and of an Order of the Lord Chancellor, by the said Charles Barlow
in the Great Seal Patent Office on the 9th June 1858.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, Charles
BARLOW, of the Office for Patents, 89, Chancery Lane, London, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-third day of November, in the year of our Lord
One thousand eight hundred and fifty-seven, in the twenty-first year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto ine, the
said Charles Barlow, Her special licence that 1, the said Charles Barlow,
my executors, administrators, and assigns, or such others as I, the said Charles
Barlow, 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

page_text: Channel Islands, and Isle of Man, an Invention for "IMPROVEMENTS IN
STEAM AND AIR ENGINES, AND FURNACES THEREFOR," upon the condition (amongst
others) that I, the said Charles Barlow, 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
bo filed in the Great Seal Patent Office within six calendar months next
aud immediately after the date of the said Letters Patent.
NOW KNOW YE, that I, the said Charles Barlow, 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, that is to say :-
The general principles or character of said Invention consist in generating
steam in a boiler heated by a closed furnace which is furnished with com-
pressed air, and in then first using the steam, which may be superlicated or
not before such use at a high-pressure in one engine, or in a cylinder resem
bling that of any high-pressure steam engine, to act upon both sidos of a
piston, and then, after such steam is exhausted therefrom, again superheating
such steam before it passes to a larger cylinder, which may be either "high-
pressure" or "low-pressure or condensing ;" and in the employment, in con-
junction with such superheated steam, of the gaseous products of the com-
bustion of the coal or other fuel, and which gaseous products of combustion,
with heated air, may be mixed with the superheated steam, which in the case
of "high-pressure" engines may be used upon both sides of the piston of the
larger cylinder; or such gascous products of combustion, with the heated air,
inay be used on one side of the piston of the larger cylinder and the steam
upon the other, as in low-pressure engines; or these may be used seperately
on seperate engines, whereby the benefits of high and low-pressure, and of
condensation and vacuum, can be made available and in the most effective
manner; and in also so arranging the superheating surfaces as to maintain
and introduce the temperature in the engine at such a point that lubrication
with oil can be made use of.
As before stated, tho application of the closed furnace with the use of
superheating surfaces to superheat the steam,and the use of such superheated
steam with the gaseous products of combustion and heated air, may be ren-
dered available either with "high" or "low" pressure engines. When applied
to high pressure, the operation is in general terms as follows:-The steam
generated in the boiler, and heated by a closed furnace, is superheated by
passing it through a heater, placed either outside of or within the closed

page_text: furnace, or heated in the steam space of the boiler by pipes, through which
the gaseous products of combustion and heated air from the furnace are
caused to circulate, and after being thus heated is conveyed to a cylinder,
in which it acts upon a piston in the same manner as it would in a common
high-pressure or non-condensing engine, and after being exhausted therefrom
it is allowed to mix with the gascous products of combustion & heated air
from the furnace, and the mixture is conveyed to a larger cylinder than that
above mentioned, and acts therein upon a piston in the same manner as in the
cylinder of a high-pressure engine, that is, by direct pressure, and, if desired,
by expansion.
Plate 1 shews such an application, in which Fig. 1 is a longitudinal eleva-
tion, partly in section, of the boiler and furnace or generating apparatus, and
such parts of au engine as are necessary to illustrate such Invention; Fig. 2
is a plan of the same, also partly in section; Fig. 3 is a transverse vertical
section in a plane through the line a, z, of Fig. 1; and Fig. 4 is a transverse
vertical section in a plane through the line y, y, of Fig. 1.
u,
B is the outer shell of the boiler or generating apparatus, substantially like
the outer shell of a locomotive boiler; A is the fire-box, in form like that of
a locomotive boiler; C is a large cylindrical chamber, arranged within the
cylindrical portion of the shell, and extending from a short distance behind
the fire-box to the extreme rear of the boiler, said chamber having com.
munication at the lower part of its front end with the fire-box by a wide
throat or passage b, and communicating at the upper end at its rear end
with the chimney D. Such chimney is fitted with a valve
which is only
opened to light the fire, or for any purpose which may require it open when
the engine is not in operation. The space between the cylindrical portion of
the shell of the boiler and the chamber Cis for water and steam, as well as the
space between the fire-box and the outer shell, the water covering always the
fire-box and the chamber C. E is a steam chamber surrounding the chimney;
F is a trunk, through which fuel is supplied to the fire-box A while the
apparatus is in operation, said trunk being situated on the top of the fire-box,
and being fitted with two hinged valves d and e, one above the other, which
are opened one at a time to admit the fuel to the fire-box; one being always
closed, to prevent the escape of the gaseous products of combustion and heated
air, which, when the apparatus is in operation, have always a considerable
pressure above that of the atmosphere. G is a fuel distributor, consisting of a
plate or grate screwed to a shaft g, which passes through stuffing boxes to the
outside of the boiler, where it has a lever f, by which such distributor can be
set at different inclinations to distribute the fuel longitudinally upon the

page_text: furnace gratej, j. The grate bars, which consist of wrought-iron tubes, and
have provision made for a circulation of water through them, are arranged to
give descent to the fuel from the centre towards the sides of the grate, and
thus cause a lateral distribution of the fuel, as seen in Fig. 1. I is the pipe
by which the compressed air is supplied to the furnace from the air com-
pression pump H, such pipe entering the furnace below the grate, & having a
branch pipe i, of smaller size, to convoy a portion of air into the lower part of
the feeding trunk F, below the valves d and e, from whence it is distributed in
the upper part of the fire-box to promote the combustion of the gases and
smoke evolved from the fuel. The fire-box is to be furnished with transparent
media for the purpose of inspecting the fire, but these being well known need
not be fully described. k, k,,, and h, k, are tubes for superheating
the steam before its transmission to the high-pressure cylinder O, to work the
piston therein. The pipes k, l,,, are closed at both ends, and are
of arched form, and are arranged vertically within the chamber C; the two
former at the rear and the two latter at the front end. The two pipes in front
have a central partition, and the two at the rear aro further subdivided by two-
other partitions n, n, Fig. 4, so that the rear pipes have four compartments,
while the front ones have but two; such front and rear pipes are also con-
nected by horizontal pipes h, k, placed near together, so as to line the upper
part of the chamber C. The steam is conveyed from the chamber E to this
heater by means of the pipe M, or the steam inay be first caused to pass
through a heater E', kept hot by a circulation of the products of combustion
through and about the tubes of it, which has two branches m, m, to each of
which connect the short pipes m', m³, Fig. 2, so as to connect with the two
lower compartiments of the pipes k, k, into which being admitted it is caused
by the pressure in the boiler and by expansion to pass through one half of the
pipes k, k, into the two upper compartments of the pipes k, k', from whence
it is collected by short pipes w, w, and a funnel-shaped connection p, into a
pipe N, couveying the steam to the valve chest O* of the high-pressure steam
cylinder O; or the steam may be heated by leading pipes from the chamber
C through or around the upper part of the space between the said chamber
and the shell B. P' is a pipo for conveying the hot gaseous products of com-
bustion and air directly from the chamber C to the pipe Q, in which they are
mixed with the exhaust steam from the cylinder O, & which conducts the
mixture to the combined steam and hot gas and air cylinder L, to work the
piston theroin; such pipe P is furnished with a cockq,bywbich it can be closed
when it is desired to convey the hot gases & air through a series of pipes
R, R, R, 7, r, through the water and steam space of the boiler, to cause their

page_text: وق
temperature to be reduced' after leaving the chamber C, by having more of
their heat abstracted by the water and steam in the boiler previously to their
admixture with the exhaust steam from the cylinder O, and being passed iuto
the cylinder L. The pipe R is an arched upright pipe like k¹¹, k, but with-
out any partition, and its arch is such that it lays nearly close in the rear of the
fire-box. The pipes R', R", whose.form is plainly seen in Fig. 4, constitute
parts of an arch corresponding with the arch of R, and, like it, are closed at
their ends. They are placed at the extreme rear of the chamber C, one on
each side, and are connected with the pipe R by the horizontal pipes r, r,
which line the upper portion of the sides of the cylindrical portion of the
shell B. The pipe R' is connected by three short pipes t, t, t, with the chamber
C, and the pipe R by short pipes s, s, s, with the pipe Q. When the cock q
is closed the hot gases and air escape through the pipes t, t, t, to the pipe R',
from thence through half the pipes r, r, to the pipe R, from thence through
the other half of the pipes r, r, to the pipe R, and from thence by the pipes
8, 5, 8, to the pipe Q. The pipe Q is furnished with a cock V behind its con-
nection with the pipe P, and by closing this cock and opening q, the whole of
the hot gases and air may be compelled to pass through the pipes R, R¹, R",
r, r, part of which being above the water level in the boiler constitute super-
heating surface, and to some extent dry or superheat the steam before it leaves
the boiler by the pipe M. T is the exhaust pipe from the high-pressure
cylinder, connecting with the hot gas and air pipe Q, near the cylinder L;
U is the exhaust pipe from the cylinder L, which, before allowing the escape
of the exhausted steam, gases, and air to the atmosphere, conducts them into
a heater V, in which they are caused to heat the water before the latter is
supplied to the boiler. The heater V consists of an upright hollow cylinder,
to the upper end of which the pipe U is connected, and near the bottom of
which is an escape pipe leading to the atmosphere. The feed pipe w from
the pump passes through the cylinder V in the form of a coil, which nearly
fills the cylinder, giving a very large amount of heating surface round about
and among which the hot air gases circulate freely.
It is not necessary to describe further the construction of the engine,
more than to say that the pistons of the cylinders O and L may be con-
nected with a beam or any other known arrangement for transmitting
motion, and the air compression pump may be driven in any convenient
manner from the beam or other part of the engine. The operation of the
whole is substantially as follows:-The boiler being supplied with water to
the proper level, the chimney valve a is opened, and a fire made in the fire-
box A. As soon as a sufficient pressure of steam is produced, the fuel box

page_text: and chimney valvo are closed tightly, and steam is admitted to the cylindor
O, which starts the engine, and sets the air compression pump in operation.
The steam exhausting from the cylinder O, escaping through the pipes T and
Q, into the cylinder L, and expanding therein, and operating by itself on the
piston of the latter cylinder until a pressure of steam of from 20 to 30 lbs. per
square inch is obtained within the furnace, when either the cock gor v, or
both, which have been up to this time closed, are opened, and the hot gases
and air from the furnace are allowed to unite with the exhaust steam from
the cylinder O, and to pass therewith into the cylinder L, to act upon the
piston thereof. In its operation I propose to maintain a pressure of steam
in the boiler of about 100 lbs to the square inch. A "cut-off" may be
employed on the cylinder O, or in the steam pipe N, to use the steam in O
expansively to such a degree as may be desirable, and a "cut-off" may also
be used in the pipe Q, so that the hot gases and air and steam may be
employed in the cylinder L, and not be allowed to escape to the atmosphere
till they have expended all or nearly all their expansive force. The tempera-
ture of the gaseous products of combustion and heated air is controlled, so as
to prevent them entering the cylinder L at so high a temperature as to
destroy the oil or grease employed to lubricate the cylinder, by making the
surface of the boiler of a very large area in proportion to the amount of fuel
consumed. The temperature at which the steam, gases, and air enter the
cylinder L may be regulated by the cocks y and v; as if the former is open
& the latter is closed, they escape directly from the chamber C to the supply
pipe Q; but it the position of the cocks are reversed, they are caused to pass
through the pipes, k, l, k, in which, as such pipes are for the most
part submerged in the water of the boiler, the temperature will be very con-
siderably reduced, and by opening both cocks 7 and to a proper relative
degree, the temperature may be still further regulated. A thermometer
placed in the pipe Q, near the valve chest L, will show the temperature of
such steam, gas, and air. An uniform, or nearly uniform, and sufficiently
low temperature being maintained in a chamber C, the steam superheating
pipes may be kept at such a temperature as to ensure their not being
destroyed, as must be the case when a heater or heaters or series of pipes
for superheating the steam are placed in any furnace with a natural draft or
open furnace, as in such a furnace it is impossible to have a properly rogu-
lated temperature; besides which, in the use of such contrivances in a closed
furnace which is only supplied with air when the engine is at work, there is
no danger of overheating them when the engine is at rost, as is sure to be
done in a furnace with an open chimney, for in the closed furnace combus-

page_text: tion almost entirely ceases as soon as the engine is stopped, and the heater or
pipes are not made hotter than when the engine is in operation; but in a
furnace with an open chimney when the engine stops, combustion proceeds,
and the heater or superheating pipes then having no circulation of steam in
contact with them, to absorb and carry away the heat, are liable to get red hot,
and are soon destroyed; and so insuperable has been this objection to the
superheating of steam in an open furnace or flues, that though the advan-
tage of superheating steam is generally conceded, the practice of it has been
almost abandoned. The use of a closed furnace in combination or connection
with arrangements for superheating the steam secures also not only the
advantages above mentioned, but secures a constant uniform temperature, not
only in the superheating tubes, but also in the cylinders, and thus preserves
an uniformity of operation not attainable in any other kind of furnace.
Instead of allowing the hot gases and air to mix with the exhaust steam, as
above described, such gases, &c., may be kept seperate therefrom, and may be
used for the purposes of superheating the steam,and by the use of a compound
heater hereafter described, heating the water to be supplied to the boiler, and
then be permitted to escape into the atmosphere at a low pressure.
Plate 2 shews the manner of applying such Invention to low-pressure
engines; Fig. 1 being a longitudinal clevation, partly in section; Fig. 2, a
plan, also partly in section; Fig. 3, a transverse vertical section of Fig. 1
through a, c; and Fig. 4, a transverse section of Fig. 1 through y, y.
As in the high-pressure engine, the steam, after being superheated or not,
as desired, is first used at a high pressure, to act upon both sides of a piston in
a cylinder resembling that of any high-pressure steam engine, and after it has
been exhausted therefrom, is conduced through a heater arranged within the
closed furnace, or placed outside of such furnace, and may first pass into such
outside heater for the purpose of having additional heat imparted to it from the
gaseous products of combustion and heated air, and its elasticity thereby in-
creased,and from thence it is conducted to a larger cylinder, which is furnished
with a condenser as in ordinary condensing engines, in which such cylinder
the superheated steam acts as in ordinary condensing engines, in which case
the gaseous products of combustion and the heated air is caused to work a
piston in what is termed a hot air cylinder, which air engine or cylinder is
additional to the main cylinder, giving additional power to the engine. The
Drawings represent such an application. Or such superheated steam, after it
leaves the heaters, may be conducted to a larger cylinder, one end of which is
connected with a condeuser like the cylinder of a condensing steam engine,
and the other end furnished with an exhaust pipe like the cylinder of a non-

page_text: condensing engine, and such steam be caused to act on that side of the piston
of such larger cylinder which communicates with the condenser, and after
forcing the piston the length of the cylinder is admitted to the condenser, and
condensed to produce a vacuum, while the gaseous products of combustion
and heated air, which are admitted at the opposite end of the cylinder, act
upon the opposite side of the piston to drive it in the opposite direction, so
that a reciprocating movement of the piston of the larger cylinder is produced
by the alterunte admission of the steam and of the gaseous products of com-
bustion and heated air.
'The boiler for generating steam is constructed substantially as for a high-
pressure engine, except that it is considerably longer in proportion, and has
two chambers C and C, which may be of any form desired, the chamber C
being much the smallest, and close to the fire, and communicating with the
fire-box A by two openings a,a, Fig. 3, which are large enough for the passage
of the whole of the gaseous products of combustion; and the other C¹ con-
necting with C by horizontal tubes b, b, in the rear portion of the boiler. The
chimney D may have in it two valves c, c, of hemispherical or other form, the
use of which is the same as in the previously described high-pressure engine.
The trunk for supplying coal,and the several parts belonging thereto, arealso
the same as those proviously described. Compressed air is furnished, both
below and above the grate, by the pipe I and its branch i from the blower H,
which is worked by the high-pressure cylinder O. The whole of the com-
pressed air is heated on its way to the furnace by passing through the henter
J, hereafter described, in which it is surrounded by the exhausted gases and
hot air transmitted from the cylinders Land M', both or either of them,
according as they are used at one end of each or only in one. Sight tubes or
transparent media are to be arranged as here before described. The arrange-
ment of the superheating pipes within the closed furnace; both the vertical
arched pipes and their horizontal connecting pipes is substantiallythe samens
that more particularly described in the high-pressure engine. The pipe P,
which conveys the gaseous products of combustion from the chamber D of the
generating apparatus through tho external hoater E, to heat the steam passing
through it, runs from the chamber or chimney D, through the interior of the
steam generating space, partly above and partly above the water line, nearly
as far forward as the fire-box, and from thence returns in a backward
direction, as shewn by the dotted lines in Fig. 2, before it leaves the boiler or
generator, so that thegaseous productsof combustion and heated air mayimpart
to the water and steam of the boiler as much of their heat as to reduce their
temperature sufficiently to enable them to be used in the cylinder M without

page_text: destroying the oil cr grease employed for lubrication. They are generally
admitted to the cylinder at a temperature of about from 400° to 500° Faren-
heit. Mis a steam dome on the top of the boiler to collect the steam, and the
pipe N conducts the steam from such dome to the valve chest of the auxillary
high pressure cylinder O, which is arranged with a piston and valves, like any
high-pressure engine. P'is the exhaust pipe of the cylinder O, leading to a heater
arranged within the chamber D,for the purpose of imparting additional heat to
& increasing the elasticity of the exhaust steam, preparatory to its admission
to the low-pressure cylinder L. in which such superheated steam acts as in an
ordinary low-pressure engine, such cylinder having the usual condensers, &c.,
and such superheated steam acting alternately upon each end of the piston.
The pipe P conveys the hot air and gases to the air cylinder and engine M¹, to
actuate the piston therein, and acting upon both sides of such piston. The
exhaust pipe U leads from the cylinder M' to the heater J before mentioned,
in which are heated both the compressed air which is supplied to the furnace
from the blower H, worked by the high-pressure cylinder O, and the water
which is supplied to the boiler. Aueduction pipe leads also from the cylinder
L to the condenser V, of such construction as is used for low-pressure or
condensing engines, and discharged of its contents by an air pump W. As
before remarked, the heater within the chamber D is arranged substantially
as the like heater before described as used in the high-pressure engine. The
heater J, in which the exhausted hot gases and air from the air cylinder M
are employed to heat the compressed air on its way to the furnace, and the
water on its way to the boiler, is composed principally of a long hollow
cylinder J, having a smaller cylinder of the some length within it. The
exhaust pipe U,conveying the hot gases and products of combustion from the
cylinder M, connects with one end of the inner cylinder, at the opposite end
of which is an escape pipe Z, leading into the atmosphere. The discharge
pipe Q from the air compression pump or blower H, iu which the cold air is
compressed, connects with the outer cylinder of J,near one end, and the pipe
I, which supplies the air to the fire, connects with such cylinder at the other
end, thus causing such compressed air to pass through the whole length of the
heater, between the two cylinders thereof, by which its temperature is raised
several degrees. The feed pipe t, for supplying the boiler, supposed to be
connected with a pump worked from the cross head of the condenser air
pump W, enters the heater J at one end, and runs several times the length
of such heater before it enters the boiler, and being surrounded by the hot
gases and air has its temperature increased very considerably.
The parts of the engine for transmitting the motive power from the pistons

page_text: may be varied in construction and arrangement according to the correspond-
ing parts of the steam engine, and need not be particularly described,,and
especially as this Invention relates to the mode of obtaining motive power
& not to its transmission.
Fig. 5 shows the arrangement of cylinders and connections when the
cylinder is not seperate and distinct, and when the superheated steam
acts upon one end of the piston in the low-pressure cylinder L, and the lot
air and gases act upon the other. In such case the cylinder L must have
a seperate valve chest and valves at each end, and the steam is intended to
act upon the upper end of the piston, and the gases upon the lower end.
Tho eduction pipe U will lead from the lower valve chest to the heater J,
and the pipo U' from the upper valve chest to the condenser V. The position
of the blower or air compression pump will also be somewhat varied, and
the hot air pipe P will connect with the lower valve chest of the cylinder L,
instead of leading to the hot air cylinder M. In such case also the cylinders
O and L may have their cylinders connected by a boam or other contrivance
for transmitting motion from the pistons; and provision should be made
for driving the air compression pump by the high-pressure steam cylinder
while the other parts of the engine are stationary, so as to obtain the requisite
pressure of air in the furnace to set in operation the piston in the cylinder L.
The combined operation of the apparatus is substantially as follows:-The
boiler having been filled with water to the proper level, and fire made, and
steam having been generated in the usual manner, with the chimney valves
open, these valves are closed,as also all entrance to the fire-box except from the
pipe I and its brunch pipe 2; steam is then admitted to the cylinder O, whose
piston, if not independent of, is disconnected from, that of the cylinder L, to
set in operation the blower R, till a pressure of from 10 to 15 lbs. por square
inch above that of the atmosphere is obtained in the furnace. As soon as the
requisito pressure is obtained in the furnace, the throttle valves in the exhaust
steam and hot air pipes are open so as to admit the superheated steam and
the hot gases and air to their appropriato cylinders, or the different ends of
the cylinder, to set the pistons in such cylinders in operation. Steam should
be employed in the high-pressure cylinder at a pressure of about 100 lbs. to
the square inch, and should be used expansively to such a degree that whon
superheated it will be admitted into the low-pressure cylinder atą pressure of
from 25 to 35 lbs., so that by employing a "cut off" and using such super-
heated steam expansively to such a degree as may be desired,its pressure will
be about the same as the effective mean pressure of the gases aided by the
vacuum when the steam is used on one side of the piston and such gases on

page_text: the other. A "cut off" is also to be used to cut off the gases and air at such
part of the stroke of the piston as may be desirable to render available to the
fullest extent their expansion, and not permit their escapo to the atmosphere
till their pressure has been reduced to nearly that of the atmosphere. The
high-pressure cylinder will be proportioned in size to the low-pressure cylinder,
according to the pressure of steam in the boiler and the expansion allowed in
the high-pressure cylinder. The cock in the air pipe i is to regulate the
supply of air so that all the smoke shall be consumed.
With the proper
proportion and disposition of the heating surfaces, and combustion being
regulated to maintain the desired pressure of steam, the temperature of the
gases and hot air may be kept uniform, or nearly so, with the highest safe
working points, say, 400° to 500° Farenheit, which admits of
proper lubri-
cation; and the temperature of such gases and air being so controlled, that of
the superheated steam will be also. There should be a large area of heating
surface compared with the amount of fuel consumed, when compared with the
heating surface of other boilers; such extent of surface will, however, depend
somewhat проп the earrangement of each case, and therefore no positiverules
can be given in respect thereto. There may also be, when desired, a receiving
vessel Y in the bottom of the chamber D, into which the steam, after having
passed through the arched and horizontal pipes constituting the heater in the
upper part of the chamber, may be conducted by means of the pipes p,p,p,p,
to be further superheated; and when desired, the gaseous products of com
bustion, as in the high-pressure engine, may be only used for superheating
the steam, and compressed air, and feed water, and not be applied upon
the pistons as a motive agent.
What is claimed as new in this Invention is,-
First, superheating the steam for use as a motive agent by passing it
through pipes arranged within a closed boiler furnace, or in contact with
any of the heating surfaces of such furnace or boiler, or by means of a
heater seperate therefrom, but kept hot by the products of combustion
taken therefrom, substantially as described.
Second, using such steam in "high prossure" engines so called, first in one
cylinder at a high pressure, and after being exhausted therefrom, causing it
to unite with the gaseous products of combustion and heated air drawn from
the furnace, to be conveyed to and operate in another and larger cylinder,
substantially as herein described, and illustrated by Plate 1.
Third, using such steam in "low pressure" or "condensing " engines after
it has operated at high pressure in one cylinder, aud been exhausted there-
from, aud superheated to increase its expansive force, in conjunction with the

page_text: gascous products of combustion and heated air, but not mixed therewith;
such steam acting upon one side of the piston, and then condensed to produce
a vacuum, and the products of combustion and heated air acting upon the
other sido of such piston, substantially as described; or causing such super-
heated steam to act uponboth sides of the piston or such a condensing engine,
and using such products of combustion and heated air in a seperate cylinder
to actuate the piston therein, substantially as set forth and described.
Fourth,soproportiouing the heating surfaces in an apparatus for generating
and superheating steam, to be used in conjunction with, but unmixed with the
gaseous products of combustion and heated air, as to control the temperature
of the products of combustion and heated air, and prevent theiradmission to
the engine cylinders at a temperature higher than that which admits of
lubrication with oil orgrease without destruction to such lubricating material,
and also prevent the gascous products of combustion coming in contact with
the superheating pipes at such a temperature as will destray such pipes.
And, fifth, so proportioning and regulating, substantially as described, tho
heating surfaces that the steain can be admitted to the cylinders at such
temperatures as may be desired or found most advisable in any case.
In testimony whereof, L, the said Charles Barlow, have hereunto set
my hand and seal, this Ninth day of June, A. D. 1858.
CHARLES BARLOW. (L.S.)