IMPROVEMENTS IN STEAM ENGINES AND Bairros An
Year: 1880

page_text: LETTERS PATENT to George Hermann Babcock, of Plainfield, in the County of
Union, and State of New Jersey, one of the United States of America, and
Stephen Wilcox and Nathaniel Waterman Pratt, both of Brooklyn, in the
County of Kings, and State of New York, also one of the United States of
America, for an Invention of "IMPROVEMENTS IN STEAM ENGINES AND
Bairros An
PROVISIONAL SPECIFICATION left by the said George Hermann Babcock,
Stephen Wilcox, and Nathaniel Waterman Pratt, at the Office of the
Commissioners of Patents on the 26th July 1880.
GEORGE HERMANN BABCOCK, of Plainfield, in the County of Union, and State of
New Jersey, one of the United States of America, and STEPHEN WILCOX and
NATHANIEL WATERMAN PRATT, both of Brooklyn, in the County of Kings, and
State of New York, also one of the United States of America. "IMPROVEMENTS
IN STEAM ENGINES AND BOILERS, AND APPARATUS CONNECTED THEREWITH."
The first part of the Invention relates to mechanism for operating the valves,
whereby facility for reversing is attained, and also facility for changing the throw
of the valves, so as to vary the degree of the expansion of the live steam, or to vary
the cushioning of the exhaust steam, or to vary both together at will, within wide
limits. We employ semi-cylindrical valves of the style known as Corliss, with
a separate wrist-plate and a separate train of connections for the steam valves and
exhaust valves respectively. Both trains are worked by duplicate construction of
the style of link known as "Allen." The levers which adjust the two link-blocks
therein may be shifted simultaneously or independently. We provide a locking
means, whereby the levers automatically lock themselves together, so that both will
be certainly worked as one in any emergency requiring instant reversing.
All the parts are adapted to allow a rapid action of the engine. Our air pump is
specially arranged to allow the violently rapid action which sometimes results when
the screw or other propelling means is thrown momentarily out of water.
The second part of the Invention relates to provisions for insuring dry steam in
he two cylinders. We whirl the steam on its passage from the boiler to the high
[Price 1071

page_text: pressure cylinder, and cause it to throw its contained water against the interior or
a chamber, where it trickles down and is trapped out. The steam is delivered to
the first or high pressure cylinder nearly dry. After being expanded in this
cylinder and a portion changed into water by the cooling there experienced, a
portion is brought into contact with pipes or vessels through which the feed-water 5
is circulated, and heats the feed water to a high temperature. The remainder and
main portion of the low pressure steam is whirled again to free it from particles of
water resulting from condensation, and is caused to move in contact with pipes or
vessels having extended surfaces, which are heated by the water discharged at a
higher temperature from the first chamber, and also by steam from such chamber. 1
This portion of the apparatus being effectually shielded from the cooling influence
of the feed pipes, which may be closely contiguous, results in insuring a well-dried
and slightly super-heated condition of the low pressure steam adapted for
economical use in the second or low pressure cylinder.
The third part of the Invention relates to the boiler or steam generator. Our 1
improved boiler affords great freedom for circulation of the water with liberal
separating surface for the disengagement of the steam from the water, and
uniformity of action with great durability of the parts. The general form of the
shell is cylindrical, with inside furnaces and return tubes. The furnace is divided
by a vertical mid-feather or passage, with the tubes arranged to allow the steam 2
to rise from the mid-feather in volumes without obstruction, and without danger of
keeping the water away from any of the tubes. Shield plates are employed to aid
in maintaining a clear space for the water to descend each side.
In carrying out the first part of our Invention, we prefer to employ a bed-plate
supporting the upper portion of the upright framing and .the air-pump. We also
prefer to employ two cylinders mounted one over the other. The smaller or higher
pressure cylinder we prefer to be uppermost. A single piston-rod extends through
both cylinders. The part which protrudes gives motion to a cross-head, which,
through a connecting rod, gives motion in the usual manner to a crank.
A single wide eccentric is fixed on a shaft, and gives motion through independent
means to the valves of the two engines.
The upper steam valves of the two cylinders are tied together so as to work in
unison. The lower steam valves of the two steam cylinders are correspondingly
tied together, and similarly worked together under all conditions. It will be
understood that there are provisions for nicely adjusting the lengths of the rods, so
as to properly set each valve.
The corresponding exhaust valves of the two cylinders are similarly tied together
so as to work always alike, with similar provisious for adjusting. There are two
wrist-plates mounted side by side, but capable of entirely independent motions.
The common or fixed centre is fixed on the side of the lower cylinder.
Our compound link, which works on the wide eccentric, is not only a double-
ended link adapted for running both ways, but is also a duplex link having two
parallel parts. A separate link-block in each part, or single link, is connected by a
suitable rod to one of the wrist-plates. One of the link-blocks works the wrist-
plate for the steam valves, and the other link-block works the wrist-plate for the
exhaust valves. By shifting both link-blocks from one end to the other of its
respective link, the engine may be reversed. Both blocks must of course be thus
shifted simultaneously from one end to the other of their links, but each block is
capable of being shifted to and from the centre, either simultaneously with the
other, or independently thereof. By shifting the two independently we can change
the throw of the steam valves, and thus change the degree of expansive
working of the steam without changing the throw of the exhaust valves, and thus
without varying the time of the exhaust, or the amount of cushioning.
The double lever we employ is formed with front and back parts or single links
the link-blocks in each respectively working the steam and exhaust valves.
A short arm stands between the two links. It receives a pin which connects t
a lateral link, linking it to a centre on the fixed frame-work. Under the action c

page_text: "
evolving eccentric the double link confined in the manner operates with a
peculiar compound motion. It tilts or oscillates, working each end up and down,
while its whole substance, including the central part of each curved slot, rises and
sinks to the extent of the throw of the eccentric, sufficient for the lap and lead of
5 the valves. The engine will work the valves so as to turn the crank "forward
when the blocks are near one end of their respective links, and will work
"backward" when the blocks are near the other end of their respective links, and
will give a diminished throw to the valves so as to work the steam more and more
expansively as the respective blocks are moved inward from either end to the
central position, in which they are represented.
the cylinder will receive a very little steam at each revolution, sufficient to lubricate
We so proportion the parts that
the surface when the blocks are exactly in the centre of their respective links.
From a pin in the side of the front link-block extends a rod which is connected
by a pin to a front wrist-plate. This wrist-plate by its pin and rod connects to a
pin in the lever of the low-pressure cylinder.
through another pin to an arm of the upper steam valve of the high pressure
A rod from the same pin connects
cylinder.
A corresponding train of connections from a lower pin on the front wrist-plate
connects to the lower steam valves of the respective cylinders. These valves,
the steam valves of the two cylinders, are all that are worked by the front link-
block.
Another link-block connects through a pin rod and pin to the other wrist-plate,
and works the entire train of exhaust valves through corresponding connections.
The link-blocks are shifted in position in their respective links by the aid of two
band levers which are mounted free to turn together or independently on their
fixed bolt or axis. They are linked to their respective rods by rods and pins.
The levers are mounted near together with two curved rods between them which
are pivoted to and constitute in effect portions of the fixed framing. These rods
are notched and receive catches or dogs controlled by bell crank levers carried on
the respective hand levers. They are actuated by springs so as to
respective dogs with suitable bars, being held firmly in any position in which they
engage their
are left. Either lever may be shifted outward or inward on its rod so as to change
the throw of its respective set of valves for the steam or exhaust, as the case may
be, without changing the throw of the other set of valves.
arrangement bringing the levers close together makes it very easy to shift both
At the same time the
simultaneously in reversing.
We have so formed and arranged the parts that the levers will lock themselves
together automatically whenever they are brought into position side by side.
When thus engaged the engineer may by one hand applied on one lever reverse
the engine by simultaneously shifting both link-blocks in their respective links.
But whenever he desires to shift either link block without shifting the other, as is
frequently required in varying the degree of expansive working of the steam, or in
varying the degree of cushioning of the steam, he can disengage the levers and make
them entirely independent.
The device by which this engagement and disengagement of the steam and
exhaust mechanisms with each other is effected is a projection on the side of a dog,
which when the levers are moved past each other, traverses over a notched shelf
xtending out under it from another dog.
Ordinarily it is expedient to hold the levers side by side.
assumed, either permanently or temporarily, the dog will, when liberated by the
When this position
and of the engineer, engage in the notch in the shelf of the other dog, and the
rst lever will thenceforward be held by the other lever, which latter is held by
s dog in the proper position on a rod.
When thus conditioned both levers may be shifted simultaneously by simply
oplying the hand in the proper position on one lever, grasping it firmly so as to
tuate a bell-crank lever and liberate its dog, and then shifting it, and with it

page_text: the other lever, either into a more central or more extreme position, according as
the steam is to be worked more or less expansively.
The cross-head is connected by a pin link and pin to a lever which turns on a
fixed centre, and is connected at its other extremity by a pin and rod, and a
suitable pin in the interior, to the hollow plunger, which works through a suitable 5
stuffing-box and guiding means to allow its serving in connection with other parts
as an efficient air-pump.
The air-pump body is formed by preference as a part of the fixed frame-work.
It is a stout shell with the ordinary interior casing fitting closely around the
plunger, which need not be especially described, but with the space exterior thereto 1
divided horizontally by a metal platform. The space above this platform is divided
in two parts by a vertical web or partition. The platform has one or more valves
opening downward on one side, the receiving side of the web, and a corresponding
provision by means of one or more valves opening upwards on the other side of
the web. Pipes connected to the nozzle enable these to serve as an air-pump, 1
receiving the water from the condenser through one nozzle and discharging it
through another nozzle.
The connection of the rod to the valve-arm, and of the corresponding rod with
or in large
the corresponding arm on the lower steam valve, may be permanent;
⚫engines these connections may be of an automatically detaching character.
The provisions for adjustment at will of the rods between the valves of the
cylinders may be omitted, taking care to adjust the parts with great accuracy in
the fitting of the rods.
The lower
In carrying out the second part of our Invention we employ an upright cylindrical
vessel standing near the engine, and preferably supported on the same bed-plate.
It is divided horizontally by an irregular-shaped partition into an upper and lower
chamber. The upper chamber contains steam at full boiler pressure.
chamber contains steam at the lower pressure, which obtains between the high
pressure and low-pressure cylinders. The steam from the boiler is received through
a pipe into a tangential nozzle, and is caused to whirl around in a small space
between the outer shell and a cylindrical curtain of smaller diameter than the main
shell, and extending down concentrically within it to near the bottom of the upper
chamber. The steam in whirling around in this chamber throws all its water
against the interior of the shell, on which surface it trickles down and gathers in
the bottom, while the steam, having parted with its water, moves inward near the
bottom and rises within the curtain and passes out through a nozzle into a pipe at
substantially the same pressure, but in a drier condition than before, to be used in
the high-pressure cylinder.
The steam is worked expansively, and on escaping through the exhaust valves of
the high-pressure cylinder flows through a pipe and enters through the lower
tangential nozzle into the lower chamber of the vessel. In this lower chamber it
is again whirled around, parting with its water by depositing it in the interior of
the shell, and passing inward under the curtain, it rises in the interion of the lower
chamber and escapes through a nozzle immediately under the partition and flows
through a pipe to the low-pressure cylinder, where it is again used and expanded
down after the fashion of other compound engines. It is finally discharged through
a pipe into a condenser, which is prevented from becoming choked by the action
of the air-pump.
The separator vessel is equipped with pipes in the interior of the lower chamber
by which important functions are performed.
To the base of the upper chamber is attached a coiled pipe, through which the
water separated from the steam at full pressure in the chamber above descends
imparting heat to the steam, which is at a lower pressure, and consequently at a
lower temperature in the chamber below. The steam at moderate pressure and
temperature is prepared for use in the low pressure cylinder by first parting with
the water produced by its cooling and expansion in the first cylinder, and then i

page_text: carried upward past the many coils of the hotter pipe, thus becoming effectually
dried and slightly super-heated. The water is allowed to escape from the bottom
of the hot coil through a trap, discharging into the space where the steam is at a
lower pressure in the lower part of the shell. In this space, subjected to a lower
pressure, it contributes its remaining heat to the quantity of steam for use in the
second cylinder. The water is trapped out from the lower chamber of the shell
through another trap into the hot well.
We employ within the shell a case partially covering a series of pipes and
preventing said pipes from exercising any refrigerating influence on the current of
weak steam passing up between this case and the curtain. These pipes contain
the feed-water, which may be received from any suitable source at any temperature
and driven by a feed pump, entering the base of the shell through a nozzle
circulating through the pipes, and being led away from the nozzle by a pipe to
supply the boiler.
The heat which is imparted to the feed water is taken from the weak steam in
the lower portion of the vessel. The heating of the feed-water condenses a portion
of such steam, and contributes largely to the water which is trapped out from the
lower portion of said case. It diminishes the quantity of low-pressure steam which
is available for use in the lower cylinder, and thus diminishes somewhat the power
of the compound engine, but we find the gain by the heating of the feed-water
to be much greater than the slight loss thus incurred.
Instead of trapping the water from a pipe into the lower part of the separator
case or shell, we can trap it into a hot well.
"
In carrying out the third part of our Invention the boiler may be of elliptical or
various other sections. The furnaces in the interior of the boiler extend nearly its
entire length, with an up-take near the back, from which tubes of small diameter
extend forward and conduct the products of combustion from the said up-take to a
"breechen at the front. The tubes fill the principal portion of the space below
the water line not occupied by the furnace; but a space is left outside of the tubes,
between them and the boiler shell, in which the water carried up by the ascending
currents of steam may flow freely downward. We provide a curved shield on
each side which separate such descending current from the ascending current of hot
water and steam arising about the tubes.
A considerable water-space or mid-feather between the furnace is strongly stayed
and open at the bottom and top to allow the motion of an active current of water.
The water moving through this mid-feather rises in a strong volume to the surface.
We omit the tubes at that point, thus providing a considerable open space for the
steam and mingled water from the mid-feather to rise actively to the surface.
The crown of the up-take at the back of the boiler is strongly stayed by bolting
to bars extending longitudinally of the boiler in a manner analogous to the stays
for the crown-sheets of locomotive and similar tubular boilers.
The crown-sheet is held at so moderate an elevation that the water surface in
the boiler will never go below it. A suitable grate or grates, in two or other
number of lengths, a fire bridge and suitable stays, as well as a drum and man-
hole or man-holes, are employed.
For very wide boilers we can have two or more mid-feathers in each case,
naking a corresponding space between the tubes above to allow the large measure
of steam ascending from each mid-feather to ascend freely to the surface, thus
acilitating the circulation and avoiding the chance of any tube being so immersed
n steam as to be kept dry.
The engine may be constructed with the cylinders side by side, and with pistons
nounted on separate piston-rods with suitable connections."

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said George Hermann Babcock, Stephen Wilcox, and Nathaniel
Waterman Pratt, in the Great Seal Patent Office on the 13th January 1881.
GEORGE HERMANN BABCOCK, of Plainfield, in the County of Union, and State of
New Jersey, one of the United States of America, and STEPHEN WILCOX and i
NATHANIEL WATERMAN PRATT, both of Brooklyn, in the County of Kings, and
"IMPROVEMENTS
State of New York, also one of the United States of America.
IN STEAM ENGINES AND BOILERS, AND APPARATUS CONNECTED THEREWITH."
The first part of the Invention relates to mechanism for operating the valves,
whereby facility for reversing is attained, and also facility for changing the
throw of the valves so as to vary the degree of expansion of the live steam, or to
vary the cushioning of the exhaust steam, or to vary both together at will, within
wide limits. We employ semi-cylindrical valves of the style known as "Corliss,"
with a separate wrist plate, and a separate train of connections for the steam valves
and exhaust valves respectively. Both trains are worked by a duplicate con-
struction of the style of link known as "Allen." The levers which adjust the two
link blocks therein may be shifted simultaneously or independently. We provide
a locking means whereby the levers antomatically lock themselves together, so
that both will be certainly worked as one in any emergency requiring instant
reversing.
All the parts are adapted to allow a rapid action of the engine. Our air pump
is specially arranged to allow the rapid action which sometimes results when the
screw or other propelling means is thrown momentarily out of water.
The second part of the Invention relates to provisions for insuring dry steam in
the two cylinders. We whirl the steam on its passage from the boiler to the high
pressure cylinder, and cause it to throw its contained water against the interior
of the chamber, where it trickles down and is trapped out. The steam is delivered
to the first or high-pressure cylinder nearly dry. After being expanded in this
cylinder, and a portion changed into water by the cooling there experienced, a
portion is brought into contact with pipes or vessels through which the feed water
is circulated, and heats the feed water to a high temperature. The remainder and
main portion of the low pressure steam is whirled again to free it from particles of
water resulting from condensation, and is caused to move in contact with pipes or
vessels having extended surfaces which are heated by the water discharged at a
higher temperature from the first chamber, and also by steam from such chamber.
This portion of the apparatus being effectually shielded from the cooling influence
of the feed pipes, which may be closely contiguous, results in insuring a well dried
and slightly super-heated condition of the low pressure steam adapted for econo-
mical use in the second or low pressure cylinder.
The third part of the Invention relates to the boiler or steam generator. Our
improved boiler affords great freedom for circulation of the water with liberal
separating surface for the disengagement of the steam from the water, and
uniformity of action with great durability of the parts. The general form of the
shell is cylindrical, with inside furnaces and return tubes. The furnace is divided
by a vertical mid-feather, with the tubes arranged to allow the steam to rise from
the mid-feather in volumes without obstruction, and without danger of keeping the
water away from any of the tubes. Shield plates are employed to aid in maintaining
a clear space for the water to descend each side.
The accompanying Drawings form a part of this Specification, and represent
what we consider the best means of carrying out the Invention.
Two cylinders are, by preference, mounted directly in line, one over the other
the smallest, or higher pressure cylinder, being uppermost. The upper cylinder is

page_text: supported in a short casting intermediate between it and the lower cylinder, which
latter is carried on a rigid frame, bolted on a short bed, bridging across a space
between wood keelsons. The air pump is built in one side of the framing and
forms a part thereof.
The boiler may be in any convenient location.
The separator, by which name we designate the apparatus which heats the feed,
removes the water from the steam at two different stages, and slightly super heats
it, may be placed in any convenient position. It is preferably constructed in a very
compact form, and we have so represented it. We have shown it close alongside
the engine; it is desirable that the passages to and from this vessel shall not be
long.

page_text: understood that there are provisions for nicely adjusting the lengths of the rods, so
as to properly set each valve.
The corresponding exhaust valves of the two cylinders are similarly tied together
so as to work always alike, with similar provisions for adjusting.
There are two wrist-plates mounted side by side, but capable of entirely
independent motions. The common or fixed centre is marked c. It is fixed on
the side of the lower cylinder C.
"
Our compound link, which works on the wide eccentric E³, is peculiar. It is
analogous to what is known as an Allen" link, but is not only a double ended
link adapted for running both ways, but is also a duplex link having two parallel
parts. A separate link-block in each part or single link is connected by a suitable
rod to one of the wrist-plates. One of the link-blocks works the wrist-plate for
the steam valves, and the other link-block works the wrist-plate for the exhaust
valves. By shifting both link-blocks from one end to the other of its respective
link the engine may be reversed. Both blocks must of course be thus shifted
simultaneously from one end to the other of their links, but each block is capable
of being shifted to and from the centre, either simultaneously with the other,
or independently thereof. By shifting the two independently we can change the
throw of the steam valves, and thus change the degree of expansive working of the
steam without changing the throw of the exhaust valves, and thus without varying
the time of the exhaust or amount of cushioning.
I will refer to the duplex or double link as an entirety by the single letter F,
but the front and back parts, or single links of which it is composed, we will
denote respectively as g and h. The link-blocks in each are correspondingly
marked, G for the front link-block working the steam valves, and H for the back
link-block working the exhaust valves.
A short arm stands between the two links marked F¹¹. It receives a pin which
connects to a lateral link F3 linking it to a centre f on the fixed frame-work.
Under the action of the revolving eccentric E2 the double link F, confined by the
link F2, operates with a peculiar compound motion. It tilts or oscillates, working
each end up and down vigorously, while its whole substance, including the central
portion of each curved link g and h, rises and sinks to the extent of the throw of
the eccentric E sufficient for the lap and lead of the valves. This gives, properly
conditioned, the effect of the well known "Stephenson" link motion. The engine
will work the valves so as to turn the crank "forward" when the blocks G, H, are
near one end of their respective links g, h, and will work "backward" when the
blocks G, H, are near the other end of the respective links g, h, and will give a
diminished throw to the valves, so as to work the steam more and more expansively
as the respective blocks G and H are moved inward from either end to the central
position, in which they are represented. We so proportion the parts that the
cylinders will receive a very little steam at each revolution when the blocks G, H,
are exactly in the centre of their respective links g, h, equal to the lap and lead.
From a pin G' in the side of the link-block G extends a rod G2 which is connected
by a pin G³ to the front wrist plate G4. This wrist plate by its pin G5 and rod Go
connects to the pin G' in the lever or arm G8 of the upper steam valve of the
cylinder C. The rod Go from the same pin G' connects through a pin Go to the
arm G of the upper steam valve of the upper cylinder B.
A corresponding train of connections from a lower pin G12 on the wrist-plate G¹
connects to the lower steam valves of the respective cylinders. These valves, the
steam valves of the two cylinders, are all that are worked by the link-block G.
The other link-block H connects through a pin H¹, rod H2, and pin H³, to the
other wrist-plate H, and works the entire train of exhaust valves through
corresponding connections, as will be obvious.
The link-blocks G and H are shifted in position in their respective links g, h, by
aid of two hand levers G₁s, H₁s, which are mounted free to turn together or
independently on the fixed bolt or axis f. They are linked to the respective

page_text: rods G, H, by rods G15, H15, and pins G, G, H, H. The levers G¹³, H¹s, are
mounted near together, as indicated in Figure 2, with two curved rods As between
them, which are pivoted to and constitute in effect portions of the fixed framing.
These rods are notched, and receive catches or dogs G1, H17, controlled by bell
crank levers G¹³, H¹³, carried on the respective hand levers G¹³, H¹³. They are
actuated by springs, not shown, so as to engage their respective dogs with the
bars A³, being held firmly in any position in which they are left. It follows that
either lever G³, H¹³, may be shifted outward or inward on its rod A³ so as to
change the throw of its respective set of valves for the steam or exhaust, as the
case may be, without changing the throw of the other set of valves. At the same
time, the arrangement bringing the levers close together makes it very easy to shift
both simultaneously in reversing.
We have so formed and arranged the parts that the levers G¹³, H¹³, will lock
themselves together automatically whenever they are brought into position side by
side. When thus engaged, the engineer may by one hand applied on the lever H¹³,
reverse the engine, simultaneously shifting both link-blocks G and H in their
respective links g, h. But whenever he desires to shift either link-block without
shifting the other, as is frequently required in varying the degree of expansive
working of the steam, or in varying the degree of cushioning of the steam, he can
disengage the levers G's, H's, and make them entirely independent.
The device by which this engagement and disengagement of the steam and
exhaust mechanism with each other is effected is shown in Figures 6 to 9, where
G* represents a projection on the side of the dog G", which, when the levers G¹³, H¹³,
are moved past each other, traverses over a notched shelf H* extending out under
it from the dog H¹.
Ordinarily it is expedient to hold the levers G13, H13, side by side. When this
position is assumed, either permanently or temporarily, the dog G¹ will, when
liberated by the hand of the engineer, engage in the notch in the shelf H* of the
other dog H, and the lever G15 will thenceforward be held by the other lever H¹³,
which latter is held by its dog H" in the proper position on the rod A³, as will
be understood.
When thus conditioned, both levers may be shifted simultaneously by simply
applying the hand in the proper position on the lever H³, grasping it firmly so as
to actuate the bell crank-lever H18 and liberate its dog H, and then shifting it,
and with it the engaged lever G¹³, either into a more central or more extreme
position, according as the steam is to be worked more or less expansively.
And when thus conditioned it is desired to reverse the engines the engineer
simply applies his band to liberate the lever H3 as before, and applying sufficient
muscular force moves the lever H3 and with it the engaged lever G³ past the
central position, and over so far towards the other extreme position as shall be
desired. Whenever he leaves it the dog H" will engage with the proper notch in
the rod A³ and hold not only the lever H, which he grasped directly, but also the
other one G13, which has been necessarily carried with it.
It will now be seen that wherever only the lever H's is operated and the other
ever G¹s is neglected, the shelf H* carried on the dog H will automatically lift
he dog G7 of the other lever G₁ whenever one lever is moved past the other,
nd engaging it with itself compel the said other lever G¹³ to travel with it until
he engineer intentionally disengages it. This greatly facilitates the working and
eversing of the engines in emergencies, as a threatened collision or the like. But
t is easy to move the lever G18 past the lever H¹³ without engaging them together
while the dog H" is down, because the same elevation of the dog G", which is
equired to clear it from the notches in A³, will, when it is to be moved, carry it
cross over the shelf H* without touching.
Our air pump is peculiarily adapted to allow of rapid motion without injury.
Dur engine is adapted to make two hundred or some high number of revolutions
er minute when working properly, But as all marine engines are liable to run
much faster k
or race " in consequence of the screw being thrown temporarily out

page_text: of the water at intervals, we provide an air pump which will allow of such motion
as high as 600 revolutions per minute.
The cross head D' is connected by a pin I, link I, and pin I², to a lever I³, which
turns on a fixed centre i, and is connected at its other extremity by a pin I* and
rod 15, and a suitable pin in the interior to the hollow plunger 16, which works 5
through a suitable stuffing box and guiding means to allow its serving in
connection with other parts as an efficient air-pump.
The air pump body J is formed as a part of the fixed frame-work. It is a stout
shell with the ordinary interior casing fitting closely around the plunger which
need not be especially described, but with the space exterior thereto divided 1
horizontally by a metal platform J'. The space above this platform J' is divided
in two parts by a vertical web or partition J². The partition J has one or more
valves J³ opening downwards on one side, the receiving side of the web Ja and a
corresponding provision by means of one or more valves J' opening upwards on
the other side of the web. Pipes not shown connected to the nozzles J5, Jo, enable
these to serve as an air pump receiving the water from the condenser, not shown,
through the nozzle J³, and discharging it through the nozzle Jo.
The peculiarity of this arrangement is, that by reason of the small cross-sectional
area of the plunger Iº, and the great horizontal area of the pump-body, J, the
rapid descent and ascent of the plunger 16 causes only a slight rising and falling of
the water surface in the pump body. The water surface alternates between rising
up to and forcing a portion of the water up past the horizontal platform J¹, and
sinking an inch (two centimetres) more or less, and drawing down water from the
receiving compartment to fill it. The motion is to so slight an extent that the
dense fluid will perform this rising and sinking motion, and induce a corresponding
motion of the valves, as many as five hundred or a thousand times a minute, for a
brief interval without inducing fracture.
Modifications may be made in the forms and proportions of the details of this
part of our Invention. In taking the steam from the boiler to the upper cylinder
I conduct it through a vessel M in which it parts with any water which has been
brought over from the boiler, and in being transferred from the upper cylinder B to
the lower cylinder C, it passes through another portion of the same vessel and
first parts with its water of condensation, and subsequently by the contact with
surfaces heated by the hotter steam above is thoroughly dried and slightly
super-heated before it is used in the lower cylinder C. These points we esteem
very important, but they may be omitted.
The connection of the rod Go to the valve arm G³, and of the corresponding rod
with the corresponding arm on the lower steam valve, may be permanent, as
shown; or in large engines these connections may be of the automatically
detaching character, such as are employed in what are known as “ Corliss" engines.
We prefer for all small engines a positive and permanent connection.
The provisions for adjustment at will of the rods G9 between the valve of the
upper and lower cylinder may be omitted, taking care to adjust the parts with
great accuracy in the fitting of the rods.
Some portions of this part of the Invention may be used with advantage without
the others, but we prefer the whole used together. Our levers G¹³, H, and their
several attachments, may be used with advantage on simple engines.
With either simple or compound engines we can lock the exhaust lever H¹s in
the best position for exhausting and cushioning with the proposed rate of revolution
and then shift the link-block Ğ and its connecting train of mechanism by hand or
by the action of a governor.
Some of the advantages due to certain features of this part of the Invention may
be separately enumerated as follows:-
First. By reason of the connections G, H, between the several valves of the
high pressure cylinder B and the corresponding valves of the low pressure
cylinder C we are able to work the valves of both engines by the same mechanism,
and to ensure that the initial pressure in the receiver shall be uniform.

page_text: Second. By reason of our duplex or double "Allen" link g, h, and separate link-
blocks G, H, and their attachments for the steam and exhaust valves respectively,
we are able by simple means to reverse at will and also to vary the throw of the
steam and exhaust valves either equally or unequally.
Third. By reason of the levers G, H, arranged side by side on the same axis,
but turning independently and connected respectively to the trains of mechanism
for operating the steam and exhaust valves, we are able to more conveniently reverse
and change the conditions for working the steam and exhaust valves together or
separately as may be required.
Fourth. By reason of the projection G* on the dog G¹7 of the one lever G¹³, and
of the shelf H* on the dog H7 of the lever H3, we are able to more conveniently
work the levers together and to ensure their simultaneous working in sudden
emergencies, as rapid reversing.
Fifth. By reason of the air-pump-plunger I being of small area, working, as
shown, within a case J of large area, having the horizontal partition J', web Ja,
and valves J³, J, arranged as shown, we are able, with a small stuffing-box and
little friction or leakage to ensure that the most rapid revolutions of the engine
shall only cause a moderate rising and sinking of the large area of the water in
the case J, and thus to obtain a gentle action on the valves J³, J, and all the parts.
We will now describe the second part of our Invention..
M is an upright cylindrical vessel standing near the engine and preferably
supported on the same bed plate. It is divided horizontally by an irregular-shaped
partition M. The upper chamber contains steam at full boiler pressure. The
lower chamber contains steam at the lower pressure which obtains between the
high and low pressure cylinders. The steam from the boiler is received through
the pipe K into the tangential nozzle M, and is caused to whirl around in a small
space between the outer shell and a cylindrical curtain M³, of smaller diameter than
the main shell, and extending down concentrically within it to near the bottom
of the upper chamber. The steam in whirling around in this chamber throws all
its water against the interior of the shell M, on which surface it trickles down and
gathers in the bottom, while the steam, having parted with its water, moves inward
near the bottom and rises within the curtain M³ and passes out through the
nozzle Minto the pipe K2 at substantially the same pressure but in a drier condition
than before, to be used in the upper cylinder B.
The steam is worked expansively, and on escaping through the exhaust valves of
the upper cylinder B flows through the pipe L', and enters through the lower
tangential nozzle M5 into the lower chamber of the vessel M. In this lower
chamber it is again whirled around, parting with its water by depositing it in the
interior of the shell, and passing inward under the curtain M it rises in the
interior of the lower chamber and escapes through a nozzle M7, immediately under
the partition M³, and flows through a pipe L2 to the lower cylinder C, where it is
again used and expanded down after the fashion of other compound engines. It
is finally discharged through the pipe O into the condenser, which, in Figures 3
and 13, is understood to be a pipe or chamber presenting a suitable surface mounted
in or under the bottom of the vessel. The condenser is prevented from becoming
choked by the action of the air pump, as will be understood.
The separator vessel is equipped with pipes in the interior of the lower chamber,
by which important functions are performed.
To the lower base of the upper chamber is attached a pipe, coiled as indicated
by P. Through this pipe the water separated from the steam at full pressure in the
chamber above descends, imparting heat to the steam, which is at a lower pressure,
and consequently at a lower temperature, in the chamber below. The steam at
moderate pressure and temperature is prepared for use in the lower cylinder C by
first parting with the water produced by its cooling and expansion in the first
ylinder, and then is carried upward past the many coils of the hotter pipe P, thus
becoming effectually dried and slightly super-heated. The water is allowed to
escape from the bottom of the hot coil P through a trap, not represented,
.

page_text: discharging into the space where the steam is at a lower pressure in the lower part
of M. In this space, subjected to a low pressure, it contributes its remaining heat
to the quantity of steam for use in the second cylinder. The water trapped out
from the lower chamber of the vessel M through another trap into the hot well.
Qis a case partially covering a series of pipes R, and preventing said pipes from
exercising any refrigerating influence on the current of weak steam passing up
between this case Q and the curtain M. The pipes R contain the feed water,
which it will be understood may be received from any suitable source at any
temperature and driven by a feed pump, not represented, entering the base of the
vessel M through a nozzle Ms, circulating through the pipes R, and being led away
from the nozzle M to a pipe, not represented, to supply the boiler.
The heat which is imparted to the feed water is taken from the weak steam in
the lower portion of the vessel M. The heating of the feed water condenses a
portion of such steam, aud contributes largely to the water which is trapped out
from the lower portion of the said case. It diminishes the quantity of low pressure
steam which is available for use in the lower cylinder Ĉ, and thus diminishes
somewhat the power of the compound engine, but we find the gain by heating of the
feed-water to be much greater than the slight loss thus incurred.
We can, if preferred in any case, instead of trapping the water from the pipe P
into the lower part of the separator case M, trap it into the hot well, not represented,
but we prefer the arrangement first described for the reason, amongst others, that
it allows the heat and steam given off therefrom, when subjected to the lower pressure,
to be utilized in the lower cylinder.
The compound engine may be constructed with the cylinders side by side, and
with pistons mounted on separate piston rods with suitable connections, but we
prefer the arrangement shown.
Modifications may be made in the form and proportions of the details of this part
of the Invention.
It will be understood that the vessels may be clothed in felt or other suitable non
conductor to economize the heat.
The plate Mo, in which are set the feed-heating-pipes R, is removable to facilitate
the removal of these parts for examination and repairs. In using some kinds of
water these pipes will require cleaning or exchanging at intervals, by reason of their
accumulating carbonate of lime or other foreign matter.
Some of the advantages due to certain features of the Invention may be separately
enumerated as follows:-
First. By reason of the tangential position of the pipe K' and of the hanging
curtain M³, extending down in the position represented within the upper portion of
the separator M, we are able to whirl the steam rapidly and thoroughly in the
concentric space between the curtain and the exterior, thereby throwing off the
dense water to the outer surface, where it trickles down, and to take the dry steam
inward under the lower edge of the curtain, and carry it upwards to be taken away
through the passages K³ and to discharge it in a dry condition; while by the
arrangement of this entire chamber in the top of the separating vessel the space is
utilized, and the water trickling down is favourably situated for imparting its heat
to the steam at lower pressure, which is to be whirled below.
Second. By reason of the pipes L1, L2, the lower chamber of the separator M being
interposed in the passage of the steam from the high pressure cylinder B to the low
pressure cylinder C, and of the curtain M, arranged therein as shown, we insure the
mechanical removal of the water produced by condensation, and leave the steam in
favourable condition either for direct use in the lower cylinder or for being
economically dried or super-heated previous to such use.
Third. By reason of the pipe P, arranged as shown, we are able to utilize
the heat in the water being trapped out of the upper chamber, and also to act with
much advantage by the heat of the steam at full pressure which follows such water
and fills a large portion of such pipe. The heat from both sources is presented
favourably for the evaporation of the last particles of moisture in the low pressure

page_text: Steam, and such steam is thereby prepared for more than usually economical use in
the large cylinder C.
Fourth. By reason of the feed pipes R, arranged as shown, we are able to beat the
feed water at the expense of a portion of the low pressure steam between the high
and low pressure cylinders without appreciably affecting the dryness of the steam
delivered to the second cylinder.
We will now proceed to describe the third part of our Invention, which relates to
the boiler.
Figures 20 and 21 illustrate this part of the Invention.
The boiler may be elliptical, or of various other sections; we prefer it of circular
section, and have so represented it.
The furnaces T1, T2, in the interior of the boiler T, extend nearly its entire length
with an up-take T3 near the back, from which tubes W of small diameter extend
forward and conduct the products of combustion from the said up-take to a
breechen T at the front. The tubes W fill the principal portion of the space
below the water line not occupied by the furnace, but a space is left outside of the
tubes, between them and the boiler shell, in which the water carried up by the
ascending currents of steam may flow freely downwards. I provide a curved
shield Z on each side, which separates such descending current from the ascending
current of hot water and steam arising about the tubes.
A considerable water space or mid-feather t, between the furnaces T1, T2, is
strongly stayed, and open at the bottom and top to allow the motion of an active
current of water. The water moving through this mid-feather rises in a strong
volume to the surface. I omit the tubes at that point, thus providing a considerable
open space w for the steam and mingled water from the mid-feather to rise actively
to the surface.
The crown of the up-take at the back of the boiler is strongly stayed by bolting
to bars T extending longitudinally of the boiler in a manner analogous to the stays
for the crown sheets of a locomotive, and similar tubular boilers.
The crown sheet is held at so moderate an elevation that the water surface in the
boiler will never go below it.
X is the grate, indicated in two lengths, and a¹ the fire bridge. Y is a longitudinal
stay, T a dome, and T6 a man-hole.
Z, Z, are the circulating plates.
Modifications may be made in the forms and proportions of the details of this
part of the Invention.
For very wide boilers we can have two or more mid-feathers t, in each case
making a corresponding space w between the tubes W above to allow the large
measure of steam ascending from each mid-feather to ascend freely to the surface,
thus facilitating the circulation, and avoiding the chance of any tube being so
immersed in steam as to be kept dry.
Some of the advantages due to certain features of this part of the Invention may
be enumerated as follows:-
First. By reason of the furnaces T1, T2, and tubes W, W, arranged as shown, with
the mid-feather t in line with the space w, we are able to better examine, clean,
and repair the parts, and also to insure that the circulation of water upward
through the mid-feather shall be unimpaired, and that the great volume of steam
rising through the space t, w, shall not keep the water away from any of the tubes.
Second. By reason of the circulating plates Z arranged as shown, a little within
the shell T, and exterior to the tubes W and furnaces T¹, T2, we insure an
undisturbed passage for the descent of the water which is thrown up with the
steam in the more central parts.
Third. By reason of the shell T, double internal furnaces T', T2, with their
dividing space or mid-feather t, the up-take T3, return tubes W, with its space w
and circulating plates Z, all combined and arranged as shown, we insure the
required combination of qualities adapting our boiler to supply steam regularly and
reliably, and to disengage it well from the water or avoid foaming.

page_text: Having thus described our Invention, we would have it understood that we do
not confine ourselves to the exact details shown and described, so long as the
peculiar characteristics of our Invention be retained, substantially as described.
But what we do claim as our Invention is,―
1st. A compound engine having the independent steam and exhaust valves of
the two cylinders connected together and worked by a single operating means,
substantially as herein specified.
2nd. The combination with a steam engine having separate steam and exhaust
valves, of the eccentric E², links g, h, and separate link-blocks G and H, with their
trains of connections, as herein specified.
3rd. In a steam engine having independent sets of mechanism for adjusting the
degree of expansion, the two levers G¹³, H¹³, combined and arranged relatively to
each other and to the valve operating mechanism, as herein specified.
4th. In a steam engine, the dog G having a projection G* in combination with
the dog H having the shelf H*, and the levers G¹³, H¹³, notched bar or bars A³,
and the trains of mechanism for separately operating the steam and exhaust valves,
as herein specified.
5th. The vertical air pump J having the slender plunger I operating with a
long stroke, working a pump having a large longitudinal area, and adapted to give
a large area of water surface, or effective piston with a small amount of throw, as
herein specified.
6th. The pipes K', K², separator M, and internal hanging curtain M³, combined
and adapted to serve between an engine and boiler, as herein specified.
7th. The pipes L', L2, in combination with the lower chamber of the separator M
having the hanging curtain M6, and with the cylinders B, C, of a compound engine,
combined as herein specified.
Sth. The coiled pipe P in combination with the separator M, horizontal
partition M', pipes K', K², curtain M³, pipes L', L2, and curtain M6, with
provisions for discharging the water from both the upper and lower parts of
the separator M, as herein specified.
9th. The separator M having the horizontal partition M³, pipes K¹, K², L¹, L²,
curtains M³, M6, shield Q, and one or more feed pipes R, combined as herein
specified.
10th. In a boiler having a furnace T¹, T2, and tubes W above it, as shown, the
mid-feather t between the two portions of the furnace, and the space w between the
corresponding sets of tubes, as herein specified.
11th. The circulating plates Z, Z, in combination with the shell T and tubes W,
and arranged to serve as herein specified.
12th. The combination in a steam boiler of the internal furnaces T1, T2, and
mid-feather t, up-take T3, tubes W, space w, and circulating plates Z, Z, arranged
to serve as herein specified.
In witness whereof, we, the said George Hermann Babcock, Stephen Wilcox,
and Nathaniel Waterman Pratt, have hereunto set our hands and seals,
this Fifteenth day of December, in the year of our Lord 1880.
GEORGE HERMANN BABCOCK.
(L.S.)