Improvements in Direct Acting Pumping Engines, Part of which Improvements are Applicable to Direct Acting Engines generally.
Year: 1886

page_text: Date of Application, 14th Dec., 1886.
Specification Accepted, 18th Jan., 1887.
[Communicated from abroad by CHARLES CAMPBELL WORTHINGTON, OF I
the State of New York, United States of America, Engineer.]
Improvements in Direct Acting Pumping Engines, Part of which
Improvements are Applicable to Direct Acting Engines generally.
I HENRY EDWARD NEWTON of the Office for Patents, 6 Bream's Buildings, Chancery
Lane in the County of Middlesex, Civil Engineer, do hereby declare the nature of this
invention and in what manner the same is to be performed, to be particularly described
and ascertained in and by the following statement :-
"direct
This invention relates to that general class of engines which are known as
acting," and more particularly to an engine of this class which is designed for pumping
liquids; or in other words, a direct-acting pumping-engine.
In an engine of this class, the same as in other classes of engines, it is, of course,
desirable, for the sake of economy, to use the steam expansively. This has heretofore
been accomplished in some cases by the use of compound cylinders, and in some cases
by the employment of one or more auxiliary or compensating cylinders and pistons,
which is or are arranged to act in opposition to the main steam piston or pistons
during the first part of the stroke of the engine, and in conjunction therewith during
the last part of the stroke, as shown and described in the Letters Patent No. 2,342 of
1884.
It is the object of the present invention, among other things, to provide means by
which the steam can be used expansively in a direct acting pumping engine, without
the employment of compound cylinders or other means for securing an even distribution
of the power throughout the entire stroke, and yet without resulting in a spasmodic or
noisy action of the engine, or an irregular discharge of the liquid from the force
main.
The invention is based upon the discovery that where the force main of the pump is
of sufficient length, the moving column of liquid in the force main can, by reason of
its inertia, be made to perform the same or substantially the same function as a
flywheel, that is to say, the column of liquid can, by reason of its inertia, be made to
D
17

page_text: absorb or take up the excess of power developed by the engine during the first part of
the stroke when the pressure in the steam cylinder or cylinders is greatest, and will
then give up this absorbed power, so as to aid the engine during the last part of the
stroke, when the pressure in the steam cylinder or cylinders is reduced by reason of
the expansion of the steam.-In order that the column in the main may perform this
function, it is of course necessary that the usual air chamber, which is located at or
near the force chamber, should be omitted.
In direct acting engines, where the stroke of the piston is not limited in length by.
the use of a crank, it has been found necessary in practice to provide some means to
overcome the momentum of the piston and the parts connected thereto at the end of
the stroke, so as to prevent the piston from coming into violent contact with the
cylinder heads, which would be liable to occasion damage. In order to effect this, it has
been common to provide this class of engines with separate induction and exhaust ports,
the exhaust ports being arranged so as to be covered by the piston as it approached the
end of its stroke, thus entrapping a small portion of steam in the end of the cylinder,
against which the piston cushioned, and was arrested as it arrived at the end of its
stroke. Where the engine is run at considerable speed, this arrangement has not
always been found sufficient for the purpose, and this has been particularly the case
where the engine exhausted into a condenser, as in such case, if the condenser were a
good one, so nearly a vacuum was formed in the cylinder, that very little steam would
be entrapped in the end of the cylinder for the piston to cushion against.-In order to
overcome this, provision has sometimes been made for the admission of a small amount
of live steam to the cylinder in front of the advancing piston just at the end of the
stroke, so as to resist the advance of the piston, and bring it to rest before it could
come into contact with the cylinder head.
The present invention also includes an apparatus for accomplishing the result just
stated, the apparatus being so organized as to be operated by the piston, as it
approaches the end of its stroke in either direction, to admit a quantity of steam in
front of it, to resist its progress, and bring it to rest.-This part of the invention
consists in a particular organization of the apparatus, by which the quantity of steam
admitted in front of the piston can be easily and quickly regulated to suit the different
running conditions of the engine, and by which the steam can be entirely cut off, when
the engine is running under such conditions as to make the admission of steam in front
of the piston unnecessary.
As a full understanding of the invention can be best given by an illustration and
description of an engine embodying the same, all further preliminary description of
the invention will be omitted, and a description of such an engine given, reference
being had to the accompanying drawings, in which :-
Fig. 1 is a side elevation, partly in section, of a single direct-acting pumping engine
embodying this invention.
Fig. is a sectional elevation, upon an enlarged scale, of the steam end of the
engine, or engine proper, and a part of the water end of the engine or pump proper.
Fig. 3 is a sectional elevation, upon a still larger scale, of the cataract apparatus for
controlling the operation of the main steam valve.
Fig. 4 is an enlarged view of a part of fig. 2, showing the construction of the
apparatus for admitting steam to one end of the cylinder.
Fig. 5 is a cross section taken on the line xx of fig. 4.
Fig. 6 illustrates a modification which will be hereinafter explained; and
Fig. 7 is a diagrammatic plan view, illustrating the manner in which the invention
be
may applied to a duplex pumping engine.
Referring particularly to figures 1 and 2, it is to be understood that A represents
the steam cylinder, and B the water cylinder of an ordinary single direct-acting
pumping engine. The piston C of the steam cylinder is connected directly to the
plunger D of the water cylinder by the piston rod a in the usual manner.-The
cylinder A is provided with the usual induction and exhaust ports 2-3, which are
controlled by an ordinary slide valve 4.-The water cylinder B is provided with the
usual suction and force chambers F, G, the former of which communicates with the

page_text: suction main H, and the latter with the force main K.-The force chamber G is not
provided with the usual air chamber to equalize the flow from the force chamber to the
main, but the force main is provided, a considerable distance from the pump, with
what is termed an equalizer, which is arranged to exert a yielding pressure upon the
column of water in the force main at that point, and thus permit the portion of the
column which is between the equalizer and the pump to move at a varying velocity
without affecting substantially the velocity of the column beyond the equalizer.―The
equalizer may be made in different ways.-As shown in fig. 1, it consists of an air
chamber L, which is about the size of, or slightly larger than the air chamber usually
located at the force chamber.-The distance which the equalizer should be removed.
from the pump, that is to say, the length of the column of liquid in the force main
between the equalizer and the pump, will depend largely upon the diameter of the
force main, the size of the pump, the length of the stroke, the speed at which it is run,
the head against which the pump is working, and the weight of the liquid being
pumped. Assuming the liquid to be pumped to be water, the diameter of the force
main twelve inches, the diameter of the pump plunger twenty inches, the length of the
stroke thirty six inches, the number of strokes per minute forty, and the head two
hundred feet, the length of the column between the pump and the equalizer should be
about five hundred feet.
The force main K will preferably be provided, just beyond the equalizer, with a
check valve 34, the purpose of which is to prevent the reaction of the column of liquid
in the main beyond the equalizer, and also to prevent that part of the force main from
becoming emptied, in case it should be found necessary to take the pump to pieces for
any purpose.
The valve 4 of the cylinder A may be operated in any of the ways common in this
class of engines; the valve operating mechanism will however preferably be of the
form shown, which will now be described.-The valve chest E of the cylinder A is so
fomed as to provide, at its ends, two small cylinders b, into which fit pistons or
plungers 30, which are connected by a rod 31, and are arranged so that their inner
ends abut against the opposite sides of a projection formed on the top of the valve 4.-
The small cylinders b are provided with single induction and discharge ports 1, which
are controlled by a small slide valve 5 located in a small steam chest e on the top of
the steam chest E.-Steam is admitted to the chests Ee through the usual induction
pipes 32-33, and after being used in the cylinders A b, is exhausted into the usual
exhaust pipes 10-11.-The inner one of the pistons 30 is provided with a rod 12,
which passes through the end of the steam chest, and is connected to a small piston 35,
which works in a cylinder c located at the end of the steam chest E.-The cylinder c is
filled with oil or other liquid, and is provided with a duct 6, which extends from end
to end of the cylinder, and is controlled by a cock or valve 7, by which the duct can
be opened to a greater or less extent, so as to regulate the circulation of the liquid
from one side to the other of the piston 35.-In addition to the duct 6, the cylinder c
is provided with two ducts 8-9, which extend from the opposite ends of the cylinder,
and open into the cylinder at points distant from its ends about two thirds of its
length. These ducts are controlled by outwardly opening check valves 13-14, which
are arranged as best shewn in fig. 3.-The valve 5 is provided with a rod 29, which
passes through the end of the steam chest e, and is connected to a short arm extending
from a rock-shaft 36 having a second arm 37, the lower end of which is connected to
the piston rod a in any of the common ways.
The engine may be provided with any suitable form of cut-off apparatus.-The
apparatus which is shown for this purpose is of substantially the same form as that
shown in the Letters Patent No. 2342 of 1884, before referred to.-It consists of two
oscillating plugs or valves 28, which are arranged in the induction ports 2, and are
provided with arms 27, which are connected by a rod 26, which is in turn connected
to a lever 25, which is connected by a rod 24 with the piston rod a.
The cylinder A is provided at each end with an opening which communicates with a
small valve chamber 21, in which is arranged a reciprocating valve 22, which closes
the opening into the cylinder.-The valves 22 are provided with stems 23, which

page_text: extend into the cylinder a short distance so as to come in contact with the piston C as
the latter approaches the end of its stroke in each direction, and with followers 40,
having ribs or projections 41, by which they are guided in the chambers 21.-The
valves are held to their seats, so as to close the openings to the cylinder, by means of
springs 42, which are arranged between the followers 40 and the ends of the
chambers 21.-It is also to be remarked, that the ends of the chambers 21 are provided
with screw plugs 43, by which access can be had to their interiors, to remove or
repair the springs.-The chambers 21 are connected by a pipe d, having a branch f,
which is supplied with live steam from any suitable source. The pipe d is provided,
on each side of the branch f, with a valve 44, by which the supply of steam admitted
to either one of the chambers 21, can be regulated or entirely cut off.
The operation of the engine thus organized is as follows:-In describing this
operation, it will be assumed that the engine is in operation, and that the parts are in
the position shown in figures 1 and 2, the engine having just completed its inward
stroke. It will be observed that just before the parts arrive in this position, the arm 37
will have rocked the shaft 36, so as to move the valve 5 into position to permit the
steam to enter the inner one of the cylinders b, and at the same time permit the steam
already in the outer one of the cylinders b, to be exhausted.-As the steam enters the
inner one of the cylinders b, it will move the pistons 30,-35 outward, and thereby
commence to shift the valve 4.-This will take place just before, or just as the piston C
arrives at the end of its stroke, as shown in figures 1 and 2.-As the pistons 30-35
are thus moved, the liquid in the cylinder c will be forced to circulate through the
duct 6 from one side to the other of the piston 35, and the duct 6 being comparatively
small, the liquid will flow through it slowly, thereby preventing the pistons 30-35
from moving quickly, so as to shift the valve 4 suddenly.-This slow movement of the
pistons 30 and the valve will prevent the live steam from being admitted through the
port 2 in front of the piston C before it has fairly come to rest, and will secure the
necessary pause or dwell at the end of the stroke, to permit the column of liquid
between the pump and the equalizer to come to rest, and the pump valves to come_to
their seats without slamming, and to prevent undue strain upon the engine.-The
duration of the pause at the end of the stroke can be readily varied and regulated by
adjusting the cock or valve 7 of the cataract apparatus, so as to permit the liquid to
circulate more or less rapidly through the duct 6.-The pistons 30 thus set in motion
will continue to move the valve 4 slowly until the valve commence to uncover the
induction port 2 at the inner end of the cylinder A, so as to admit steam behind the
piston C to start it upon its outward stroke.-As soon as this takes place, it is desirable
that the valve 4 should make the remainder of its stroke quickly, so as to fully open
the induction port 2 as quickly as possible. This is accomplished by means of the
duct 8 and valve 13. It will be observed that during the first part of the movement of
the pistons 30-35, the piston 35 covers the inner end of the duct 8, but just as the
valve 4 commences to uncover the port 2, the inner end of the duct 8 is uncovered by
the piston 35, and this permits the liquid in the cylinder c to raise the valve 13, and
flow freely through the duct 8 to the other side of the piston 35, so as to offer very
little resistance to the piston, and allow it and the pistons 30, and the valve 4, to be
moved quickly by the steam for the remainder of their stroke.
As soon as the valve has been shifted, as just described, the full pressure of the
steam will be exerted upon the piston C, to start it upon its outward stroke, and the
power thus developed will be expended in starting and moving the column of liquid in
the force main. During the first part of the stroke, when the steam is acting at full
pressure on the piston C, the power developed by the engine will be in excess of
what is required to move the column of liquid at the mean or average velocity
required, and the consequence will be that this excess of power will be expended in
accelerating the velocity of the column, and thus the column will, as the piston
approaches the middle of the stroke, acquire a greater velocity then is required. This
extra velocity will not be imparted to the whole column, however, but only to that
part of the column which is between the pump and the equalizer, and will result in
compressing the air in the chamber L.-After the engine has made a part of its stroke,

page_text: say about one-third, more or less, the valve 28, at the inner end of the cylinder A, will
arrive in position to cut off the further admission of steam to the cylinder, and the
piston C will proceed upon and complete its stroke under the expansive force of the
steam already in the cylinder.-As the steam expands in the cylinder, its pressure of
course decreases, thus reducing the power of the engine until, as it nears the end of
the stroke, the power will fall below what is required to move the column of liquid in
the force main. That part of the column between the pump and the equalizer having,
however, been accelerated during the first part of the stroke, will, by reason of its
inertia, aided by the decreasing power of the engine, continue in motion, but at a
decreasing velocity, during the last part of the stroke, and thus permit the engine to
complete its stroke. During the last part of the stroke, and during the pause before
the commencement of the next stroke, the air in the chamber L, which was compressed
during the first part of the stroke, will expand, and thus maintain a uniform or
practically uniform pressure at that point, and secure a uniform flow of the liquid
through that portion of the force main beyond the air chamber, and a uniform
discharge of the liquid from the force main.
From what has been said it will be seen, that that portion of the column of liquid
in the force main which is between the pump and the equalizer, is made, by reason of
its inertia, to perform the same function as a fly wheel, that is to say, it takes up the
excess of power developed by the engine during the first part of the stroke, when the
power is greater than is required, and gives off this power during the last part of
the stroke, when the power developed by the engine is less than is required.—It will be
seen, however, that this result could not take place if the pump was provided with the
usual air chamber at or near the force chamber, as in such case the excess of
pressure
of the steam, at the commencement of the stroke, would simply impart additional
velocity to the pump plunger, which would cause the air in the air chamber at the
-pump to be compressed, but would not impart any additional velocity to the column in
the main. From this it would result, that when the steam pressure was reduced,
during the last part of the stroke, by the expansion of the steam, the air in the chamber
would expand, and offer the same, or substantially the same resistance to the pump
plunger, and, as a result, the engine would not be able to complete its stroke.
As the piston C arrives near the end of its stroke, it will cover the exhaust port 3 at
that end of the cylinder, thereby entrapping a quantity of steam in the end of the
cylinder, against which steam the piston will cushion, and the steam thus entrapped
will offer resistance to the piston, and tend to bring it to rest.-If, however, the
momentum of the moving piston, and parts attached thereto, is so great that the steam
thus entrapped is not sufficient to bring the piston to rest, the piston will, as it arrives
near the head of the cylinder, come into contact with the stem 23 of the valve 22 at
that end of the cylinder, and thus open the valve, and admit a quantity of live steam
into the cylinder in front of the piston, and thus sufficient resistance will be offered to
the piston to prevent it from coming into contact with the cylinder head.-As soon as
the piston starts upon its return stroke, and moves a short distance away from the
cylinder head, the valve 22 will be closed by the spring 42.-The valves 44 can be
operated from time to time so as to regulate the amount of steam which will be allowed
to pass through the pipe d into the chambers 21, and thus the amount of resistance
which shall be offered to the piston C by the live steam admitted in front of it, can be
regulated to any degree of nicety. If at any time the running condition of the
engine is such, owing to the load which is upon it, or for any other reason, that it is
not necessary to admit steam in front of the piston to bring it to rest, the valves 44 can
be entirely closed, so as to shut off the steam from the pipe d and the chambers 21.
In the apparatus of this class heretofore in use, the quantity of steam admitted in
front of the advancing piston has been regulated by the position of the stems of the
valves 22, the stems being made adjustable so as to extend a greater or less distance
into the cylinder A, and thus cause the valves to be opened to a greater or less extent.-
To provide for the adjustment of the valve stems, they were made to screw into the
valves, and were operated by means of rods which extended through the ends of the
chambers 21,-When it was not necessary or desirable to admit any steam, the valve

page_text: stems were adjusted so that they would not come into contact with the piston.-It was
found in practice that it was impossible to keep the valves 22 steam tight, as foreign
matter would lodge under them to such an extent as to cause steam to constantly leak
past them, and the leak thus occasioned could not be prevented.-In the present
arrangement, however, the valves 22 are always in operation, and by this means are
kept in good order, while the admission of the steam is controlled by separate valves,
which are of such form as to prevent leakage past them.-In the former arrangements,
the engineer was obliged to adjust or regulate one valve at a time, whereas in practice
it is frequently desirable to regulate both together, and to do this very quickly.-In
the present arrangement, this can readily be done by operating the valves 44.
Just before the piston C arrives at the end of its stroke, and is arrested as just
described, the valve 5 will be shifted so as to open the port 1, to admit steam to the
outer one of the cylinders b, and the piston C will then make its inward stroke in the
same manner as just described.
When the engine is in operation, the column of liquid in the force main may not,
owing to its inertia, come to rest at once upon the completion of the stroke of the
piston C and plunger D, but continue to move in the main during the pause or dwell
of the piston and plunger.-This movement of the column will have a tendency to draw
the liquid through the pump, and will raise all of the suction and force valves, as
indicated in figure 2, but the pause of the engine at the end of the stroke will allow time
for that portion of the column between the pump and the equalizer to come to rest,
so that the valves will come to their seats, and not be slammed by the starting of the
plunger upon its return stroke.
It has already stated, that the pause or dwell of the piston C at the end of the stroke,
can be readily varied by adjusting the cock or valve 7, so as to permit the liquid in
the cylinder to circulate more or less rapidly from one side to the other of the
piston 35. From this it follows that the cock or valve 7 can be made to operate as
a governor to regulate the speed of the engine. For this purpose, the cock 7 is
provided with an arm 15, which is bifurcated at its end, and straddles a disc 16, which
is secured to the end of a small plunger 17, which enters a small cylinder or chamber 18
formed below the cylinder c, as best shown in figure 3. The chamber 18 communicates
by a pipe 50 with the force main K at or beyond the equalizer.-The disc 16 is
provided with a spring 19, which is arranged to act in opposition to the plunger 17,
and is of sufficient strength to just counteract the pressure which exists in the main
when the engine is operating at its normal speed.
From this arrangement it results, that whenever the pressure in the main is increased
beyond the proper point, this increased pressure will be communicated to the plunger 17,
and will overcome the tension of the spring 19, and operate the cock 7, so as to check
the flow of the liquid from one side to the other of the piston 35, and thus lengthen
the pause of the piston C at the end of the stroke.-As soon as the pressure in the
force main is reduced, the spring 19 will again open the cock 7.-The spring 19 is
provided with an adjusting screw 20, by which its tension can be regulated as may be
required.
From what has been said it will be seen that the volume of air in the chamber Lis
in effect a cushion or spring, or in other words, a yielding connection, interposed
between that part of the column of liquid which is beyond the air chamber, and that
part which is between the air chamber and the pump, its function being to permit the
part of the column next to the pump to move at varying velocities, without materially
affecting the velocity of the part beyond the air chamber.-This being the case, it is
apparent that other means than the volume of confined air may be employed to effect
the same result. For example, as illustrated in figure 6, the equalizer is in the form
of an accumulator, and accomplishes the same result.-As shown in said figure, the
chamber L, instead of being filled with a body of air, is provided with a plunger 38,
which is acted on by suitable weights 39.-The action of the equalizer thus formed.is
the same as the body of confined air. As the velocity of the column of liquid between
the chamber L and the pump is accelerated, and its pressure increased during the first
part of the stroke, the plunger 38 will be raised, and as the velocity and pressure

page_text: decreases during the last part of the stroke, the plunger will fall.-Of course it will be
understood that the plunger 38 may be acted on by a spring, instead of being weighted,
or that the chamber L may be a cylinder having a piston which is acted on by either
a weight or spring.-Since the action of the body of confined air, or the weighted or
spring-pressed plunger or piston, is, in effect, but a yielding weight or connection
interposed between the two parts of the column in the force main, it is evident that
any form of equalizer which will perform this function, will secure the desired effect,
and will, therefore, be within the scope of the invention.-In some cases, the equalizer
may consist of a simple stand pipe located at the point occupied by the chamber L.-
In such case, the liquid will simply rise in the stand pipe during the first part of the
stroke, and fall back to its normal level during the last part of the stroke. When a
stand pipe with an open end is employed, it must of course be somewhat higher than
the head against which the pump is working.
The present invention can be applied to duplex as well as to single pumping engines.
-In such case, each side of the engine will be provided with an independent force main
extending from the pump to the chamber L, as illustrated in figure 7.- From the
chamber L only a single main is necessary; or two or more independent pumps may
be connected to the chamber L in the same manner as the two sides of the duplex
engine.
Having now particularly described and ascertained the nature of the said Invention,
and in what manner the same is to be performed, as communicated to me from abroad
by my foreign correspondent, I declare that what I claim is :-
1. The combination with the pump, of the force main connected thereto without the
intervention of an air chamber, and an equalizer substantially such as described, located
at such a distance from the pump, that the column of liquid in the main between the
equalizer and the pump, will have sufficient inertia to perform the function of a fly
wheel, and arranged to exert a yielding pressure upon the column in the main, whereby
that portion of the column between the equalizer and the pump may move at varying
velocities, without affecting substantially the velocity of the column beyond the
equalizer, substantially as described.
2. The combination with the pump, of the force main connected thereto without
the intervention of an air chamber, and an equalizer consisting of the chamber L
containing a volume of confined air located at such distance from the pump that the
column of liquid in the main between the equalizer and the pump will have sufficient
inertia to perform the function of a fly wheel, and arranged to exert a yielding pressure
upon the column in the main, whereby that portion of the column between the
equalizer and the pump may move at varying velocities, without affecting substantially
the velocity of the column beyond the equalizer, substantially as described.
3. The combination with the cylinder c having the duct 6 and the piston 35 forming
the cataract apparatus, of the cock or valve 7, the chamber 18 having the plunger 17
connected to said cock or valve, and the pipe 50 connecting said chamber with the
force main K, substantially as and for the purposes set forth.
4. The cataract apparatus consisting of the piston 35 and the cylinder c, having the
duct 6, and the ducts 8-9 provided with the valves 13-14, substantially as described.
5. The combination with a direct-acting pumping engine and its force main, of an
equalizer substantially such as described, located at such a distance from the pump,
that the column of liquid in the main between the equalizer and the pump, will have
sufficient inertia to perform the function of a fly-wheel, and arranged to exert a
yielding pressure upon the column in the main, whereby that portion of the column
between the equalizer and the pump may move at varying velocities without affecting
substantially the velocity of the column beyond the equalizer, and means substantially
such as described whereby the speed of the engine is regulated by varying the length
of the pause of the engine at the end of each stroke, substantially as described.
6. The combination with a direct-acting pumping engine and its force main, of an
equalizer substantially such as described, located at such a distance from the pump,
that the column of liquid in the main between the equalizer and the pump, will

page_text: have sufficient inertia to perform the function of a fly wheel, and arranged to exert a
yielding pressure upon the column in the main, whereby that portion of the column
between the equalizer and the pump may move at varying velocities, without affecting
substantially the velocity of the column beyond the equalizer, and means substantially
such as described whereby the main valve of the engine is moved slowly up to the
point where the admission of steam begins, and quickly thereafter, substantially as
described.
7. The combination with the pump and its force main, of an equalizer substantially
such as described, located in the force main, and arranged to permit the inertia of the
column in the main to aid the engine during the last part of the stroke, thereby
permitting steam to be used expansively, substantially as described.
8. The combination with the cylinder A and its piston C, of the valves 22, operated
by the piston, to admit steam to each end of the cylinder, and the valves 44 for
controlling the admission of steam to the valves 22, substantially as described.
9. The combination with the cylinder A and its piston C, of the pipe d communi-
cating with each end of the cylinder, the valves 22 arranged to be opened by the piston
as it approaches the end of its stroke in either direction, the pipe f for supplying the
pipe d with steam, and the valves 44 for regulating the amount of steam admitted to
each end of the cylinder, substantially as described.
10. The combination with the cylinder A and its piston C, of the chambers 21 at
each end of the cylinder, provided with the valves 22, having the stems 23 extending
into the cylinder, the pipe d communicating with both of said chambers, the pipe f
for supplying the pipe d with steam, and the valves 44, substantially as described.