CERTAIN IMPROVE- MENTS ON THE HIGH-PRESSURE STEAM ENGINE, AND THE APPLICATION THEREOF, WITH OR WITHOUT OTHER MACHINERY, TO USEFUL PURPOSES
Year: 1815

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, RICHARD
TREVITHICK, of Cambrone, in the County of Cornwall, Engineer, send greeting.
WHEREAS His most Excellent Majesty King George the Third did, by
His Letters Patent under the Great Seal of the United Kingdom of Great
Britain and Ireland, bearing date at Westminster, the Sixth day of June, in
the fifty-fifth year of His reign, give and grant unto me, the said Richard
Trevithick, my exors, admors, and assigns, His special licence, full power,
sole privilege and authority, that I, the said Richard Trevithick, my exors,
adñiors, and assigns, should and lawfully might, during the term of years
therein mentioned, make, use, exercise, and vend, within England, Wales,
and the Town of Berwick-upon-Tweed, my Invention of " CERTAIN IMPROVE-
MENTS ON THE HIGH-PRESSURE STEAM ENGINE, AND THE APPLICATION THEREOF, WITH
OR WITHOUT OTHER MACHINERY, TO USEFUL PURPOSES;" in which said Letters Patent
there is contained a proviso that if I, the said Richard Trevithick, shall not
particularly describe and ascertain the nature of my said Invention, and in
what manner the same is to be performed, by an instrument in writing under
my hand and seal, and cause the same to be inrolled in His Majesty's High
Court of Chancery within six calendar months next and immediately after the
date of the said Letters Patent, that then the said Letters Patent, and all
liberties and advantages whatsoever thereby granted, shall utterly cease, deter-
mine, and become void, as in and by the same, relation being thereunto had,
may more fully and at large appear.

page_text: NOW KNOW YE, that in compliance with the said proviso, I, the said
Richard Trevithick, do hereby declare that the nature of my said Invention,
and the manner in which the same is to be performed, are particularly described
and ascertained as follows, that is to say :-
The first part of my said Invention consists in causing steam of a high
temperature to spout out against the atmosphere, and by its recoiling force to
produce motion in a direction contrary to the issuing stream, similar to the
motion produced in a rocket or to the recoil of a gun. The mode of carrying
this into effect will be readily understood by supposing a gun barrel to be bent
at about a quarter of its length from the muzzle, so that the axis of the two
limbs shall be at right angles to each other, and the axis of the touch-hole at
right angles to the axis of the short limb, or the limb containing the muzzle.
Then in the top of a boiler suitable to the raising steam of a high temperature
make a hole, and insert the muzzle of the gun barrel into that hole, so that
the gun barrel may revolve in the hole steam-tight, and let the short bend of
the gun
barrel be supported in a vertical position by a collar which will permit
the breech of the gun barrel to describe a horizontal circle, the touch-hole
being at the side of the barrel. If steam of a high pressure be then raised in
the boiler it will evidently pass through the gun barrel, and spont out
from the touch-hole against the atmosphere with a force greater or less
according to the strength of the steam, and, as the steam is also exerting a
contrary force against that part of the breech which is opposite to the touch-
hole, the barrel will recoil, and, because the other end is confined to a centre,
the breech end will go round in a circle with a speed proportionate to the
pressure given, and may be readily made to communicate motion to machinery
in general. This simple form of my Invention is given merely to convey
to the mind a clear idea of its nature; but in practice I do make the
revolving limb, which, for the sake of distinction, I call the arm, much greater
in its horizontal breadth than in its perpendicular thickness, in order that the
arm may meet with but little resistance from the surrounding medium during
its revolution; and I do introduce between the muzzle of the barrel and the
boiler a steam pipe with a cock or valve for the purpose of occasionally
stopping the passage of the steam, and thereby preventing the motion of the
arm without waiting or lowering the pressure of the steam in the boiler, as
well as to regulate the speed of the arm by allowing more or less steam to
pass through it; and I do attach another arm of equal weight with that first
described in an opposite direction from the center of motion to equalize the
centrifugal force, and also by acting as a balance to avoid the great friction
which would otherwise take place between the barrel and the supporting

page_text: collar. I do also construct this improvement with two or more arms having
similar perforation and aperture for the steam with the arm first described;
and I do, when more convenient, place the axis of revolution horizontal or
even inclined instead of vertical; and I do sometimes make the communication
from the steam pipe into the middle of the supporting collar, and from thence
into the barrel through a hole in that part which turns in the collar, making a
grove round the inside of the collar opposite to the hole in the barrel, or a
grove round the barrel opposite to the hole in the collar, in order to allow
the steam free passage during the whole of the revolution; and I do make the
aperture through which the steam is to spout capable of being increased
or decreased in its dimensions by means of a sliding piece worked with a
screw order to apportion the size of the aperture to the strength of the
steam, the size of the boiler, and the work to be performed; in cases where
great speed is required the revolving arms should be made short, and applied
immediately on the axis of motion, without the usual intervention of multi-
plying wheels. It is unnecessary to mention any more variations of the mode
of carrying this first part of my Invention into effect, since I claim as my
Invention the various forms of causing steam of a high pressure to pass from a
boiler through one or more perforated revolving arms, and to spout out against
the atmosphere from an aperture at the side near the extremity of the arm
or arms.
The second part of my Invention consists in causing steam of a high tempera-
ture to act upon water, and that water to operate upon a or under a piston without
permitting the steam to come in contact with the piston; by this contrivance.
I obviate the necessity of that tight packing which is required when steam of
a high temperature acts immediately on a piston. To effect this purpose I use
two vessels standing side by side, which, for the sake of bearing high pressure,
I make of a cylinder form, closed at the bottom, but connected at the lower
part by a tube. One of these cylinders, which I call the steam vessel, has a
close cover, into which are inserted a steam pipe and a discharging pipe, and
in each pipe there is a valve or cock. The other vessel, which I call the
piston cylinder, is furnished with a piston, the rod of which may be attached
to a pump or other machinery. To put this apparatus into operation the
piston is to be placed in and near the bottom of the piston cylinder, and the
steam vessel filled with water. Then the discharging valve being shut and
the steam valve opened, the steam will press on the surface of the water or
upon a piece of cork or other substance floating on the surface, and by that
pressure force the water down to the lower part of the vessel through the tube
into the bottom of the piston cylindaz, and drive up the piston without

page_text: admitting any steam to pass out of the steam vessel into the piston cylinder.
As soon as the steam has arrived near to the orifice of the tube the steam valve
is to be shut and the discharging valve opened. The steam will then escape
through the discharging pipe, and allow the piston to descend by its own
weight and drive the water back again into the steam vessel, and by that
means make a complete stroke, which may be repeated as often and with as
much force as the size and construction of the boiler will supply the requisite
quantity of steam. By the alternate passage of the same water from one
cylinder to the other the water may be kept nearly to a boiling heat, and
consequently there will be no considerable condensation of the steam on its
coming in contact with the water, and if the little condensation which will
take place should add to the quantity of water in the vessel that extra
quantity may be ejected at every stroke through a pipe and regulating cock
communicating with the piston cylinder. A double engine is to be constructed
by using two steam vessels with their valves to force water alternately on
each side of the piston, in which case the piston cylinder must be closed at
the top and the piston rod work through a stuffing box in the usual way, or
the steam vessels may be applied to force water alternately under two single
pistons working in cylinders open at the top to produce the effect of a double
engine. This engine is not capable of being used with a condenser, because
the water in the steam vessel would, if exposed to a vacuum, evaporate into
the condenser and destroy the vacuum. By lengthening the pipe of commu-
nication between the steam vessel and piston cylinder the power of this engine
may be conveyed to a great distance from the boiler without intermediate
beams or connecting shafts.
The third part of my said Invention consists in interposing the steam vessel
of the second part between the boiler and revolving arms described in the first
part, so that instead of the steam passing into the revolving arms it shall press
on the surface of the water in the steam vessel, and force the water through
the arms and out at the apertures near their extremities against the atmosphere,
and produce the revolution of the arms with more or less velocity, according to
the strength of the steam. In this case also, when the steam has forced
nearly all the water out of the vessel, the steam valve must be shut and the
discharging valve opened for the steam to escape, and at the same time
another valve or cock opened for the purpose of letting a fresh portion of
water from a reservoir into the steam vessel, when the steam is again to be
admitted from the boiler in order to force the water through the revolving arm
or arms. The arms should be inclosed in a case to prevent the steam or
water being thrown at a distance to the annoyance of the bystanders, the

page_text: bottom of which case may become the reservoir for supplying water to the
boiler and steam vessel; the top of the steam vessel should be placed at a
lower level than the bottom of this reservoir, in order that the water may flow
into the steam vessel when the communication from the boiler is cut off, and
the steam discharged. By putting flat plates or leaves upon the revolving
arms within the case a current of air may be produced in the manner of a
winnowing machine for blowing the fire, and thereby obviating the necessity of
a high chimney, when the engine is used for portable purposes.
Various modes
of opening and shutting the cocks or valves are so commonly known to all
persons conversant with steam engines that a description of them is quite
unnecessary. This third part of my said Invention is in some respects similar
to the contrivance described in many books on mechanics by the name of
Barker's Mill; but in Barker's Mill no greater power can be obtained than
what arises from the perpendicular altitude of the reservoir or head of water
above the place where it spouts out from the revolving arms, whereas in my
Invention the water being acted upon and driven out by steam of a high
pressure, which is well known to pass through tubes with very little friction
compared with water, that a much greater power will be obtained from the
same quantity of water; and as the water, after it has passed through the
revolving arms, may be made to flow back again into the steam vessel, to be
driven through the revolving arms by a succeeding portion of steam, a small
quantity of water may be made to work the engine for a long time.
The fourth part of my said Invention, and that which comes under the
second I part of my title, consists of a mode of propelling, drawing, or causing
ships, boats, and other vessels to pass through the water, which purpose I cffect
by constructing a worm or screw or a number of leaves placed obliquely round
an axis similar to the vanes of a smoke jack, which shall be made to revolvo
with great speed in a line with the required motion of the ship, boat, or other
vessel, or parallel to the same line of motion; the obliquity of the thread of
the worm, screw, or leaves admits of considerable variety, according to the
degree of velocity given to it and speed required, and according to the power
with which it is driven, but as a general medium I by preference contrive that
the thread of the screw at its outer edge shall make with its axis an angle of
about thirty degrees. This worm is in some cases to revolve in a fixed
cylinder, in others to revolve together with the cylinder, similar to the screw
of Archimedes, but generally to revolve in the water without any cylinder
surrounding it. This worm or screw may be made to revolve in the water at
the head of the ship, boat, or other vessel, or at the stern, or one or more
worms may revolve on each side of the vessel, as may most conveniently suit

page_text: the peculiar navigation on which the ship, boat, or vessel is to be employed.
In some cases when the screw is to work at the head of a ship it is to be
made buoyant and move in a universal joint at the end of an axle turning in
the bow of the ship, in order that the screw may accommodate itself to the
unevenness of the waves.
In witness whereof, I, the said Richard Previtick, have hereunto set
my hand and seal, this Twelfth day of June, in the year of our Lord
One thousand eight hundred and fifteen.

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, RICHARD
TREVITHICK, of Cambrone, in the County of Cornwall, Engineer, send greeting.
WHEREAS His most Excellent Majesty King George the Third, did,
by His Letters Patent under the Great Seal of the United Kingdom of
Great Britain and Ireland, bearing date at Westminster, the Sixth day of June,
in the fifty-fifth year of His reign, give and grant unto me, the said Richard
Trevithick, my exors, admors, and assigns, His special licence, full power,
sole privilege and authority, that I, the said Richard Trevithick, my exors,
adiñiors, and assigns, should and lawfully might, during the term of years
therein mentioned, make, use, exercise, and vend, within England, Wales, and
the Town of Berwick-upon-Tweed, my Invention of "CERTAIN IMPROVEMENTS ON
THE HIGH-PRESSURE STEAM ENGINE, AND THE APPLICATIONS THEREOF, WITH OR WITH-
OUT OTHER MACHINERY, TO USEFUL PURPOSES;" in which said Letters Patent there
is contained a proviso that if I, the said Richard Trevithick, shall not particu-
larly describe and ascertain the nature of my said Invention, and in what manner
the same is to be performed, by an instrument in writing under my hand and
seal, and cause the same to be inrolled in His Majesty's High Court of Chancery
within six calendar months next and immediately after the date of the said
Letters Patent, that then the said Letters Patent, and all liberties and advantages
whatsoever thereby granted, shall utterly cease, determine, and become void, as
in and by the same, relation being thereunto had, may more fully and at large
appear: And whereas, in compliance with the said proviso, I, the said Richard
Trevithick, did, on the Thirteenth day of June, One thousand eight hundred
and fifteen, cause to be inrolled in His Majesty's High Court of Chancery a.
certain Specification, in which it was my intention to explain the nature of
the said Invention, and the manner in which it was to be performed; but
a part of the said Invention having been, through error, omitted in the said
Specification, I am now desirous of correcting the same, and stating more fully
the nature of the said Invention, and the manner in which the same is to be
performed.
NOW KNOW YE, that in compliance with the said proviso, I, the said
Richard Trevithick, do hereby declare that the nature of my said Invention, and.

page_text: the manner in which the same is to be performed, are particularly described
and ascertained as follows, that is to say:-
Instead of a piston working in the main cylinder of the steam engine I do
use a plunger pole similar to those employed in pumps for lifting water, and I
do make the said plunger pole nearly of the same diameter as the working
cylinder, having only space enough between the polo and the cylinder to pre-
vent friction, or, in case the steam is admitted near the stuffing box, I leave
sufficient room for the steam to pass to the bottom of the cylinder, and I do
make at the upper end of the cylinder for the plunge pole to pass through a
stuffing box of much greater depth than usual, into which stuffing box I do
introduce enough of the usual packing to fill it one third high. Upon this
packing I place a ring of metal, occupying about another third part of the
depth of the stuffing box, this ring having a circular groove at the inside, and a
hole or holes through it communicating with the outside, and with a hole through
the side of the stuffing box; or, instead of one ring containing a groove,
I sometimes place two thinner rings, kept asunder by a number of pillars to
about the distance of one third of the depths of the stuffing box, and I pack
the remaining space above the ring or rings, and secure the whole down in the
usual manner. The intention of this arrangement is to produce the effect of
two stuffing boxes, allowing a space between the two stuffings for water to pass
freely in from the boiler or forcing pump through a pipe and through the hole
in the side of the stuffing box, so as to surround the plunger pole and form the
ring of water for the purpose of preventing the escape of steam by keeping up
an equilibrum between the water above the lower stuffing and the steam
in the cylinder. By this part of my said Invention I obviate the necessity of
that tight packing which is requisite when steam of a high pressure is used, and
consequently I avoid a greater proportion of the usual friction, because a very
moderate degree of tightness in the packing is quite sufficient to prevent the
passage of any injurious quantity of so dense a fluid as water. And I do
further declare that I use the plunger pole, working in a cylinder and through
a double stuffing, either with or without a condensor, according to the nature
of the work which the steam engine is to perform.
The second part of my said Invention consists in causing steam of a high tem-
perature to spout out against the atmosphere, and by its recoiling force to pro-
duce motion in a direction contrary to the issuing steam, similar to the motion &
produced in a rocket, or to the recoil of a gun. The mode of carrying this
into effect will be readily understood by supposing a gun barrel to be bent at
about a quarter of its length from the muzzle, so that the axes of the two
limbs shall be at right angles to each other, and the axis of the touch-hole at

page_text: right angles to the axis of the short limb, or the limbs containing the muzzle;
then in the top of a boiler suitable to the raising steam of a high temperature
make a hole, and insert the muzzle of the gun barrel into that hole, so that the
gun barrel may revolve in the hole steam-tight, and let the short limb of the
gun barrel be supported in a vertical position by a collar, which will permit the
breach of the gun barrel to describe a horizontal circle, the touch-hole being at
the side of the barrel. If steam of a high pressure be then raised in the
boiler it will evidently pass through the gun barrel and spout out from the
touch-hole against the atmosphere with a force, greater or less, according to
the strength of the steam; and as the steam is also exerting a contrary force
against that part of the breach which is opposite to the touch-hole, the barrel
will recoil, and because the other end is confined to a centre the breach end
will go round in a circle with a speed proportionable to the pressure given, and
may readily be made to communicate motion to machinery in general. This
à simple form of my Invention is given merely to convey to the mind a clear
idea of its nature; but in practice I do make the revolving limb, which
for the sake of distinction I call the arm, much greater in its horizontal breadth
than in its perpendicular thickness, in order that the arm may meet with but
little resistance from the surrounding medium during its revolution, and I do
introduce between the muzzle of the barrel and the boiler a steam pipe with a
cock or valve for the purpose of occasionally stopping the passage of the steam,
and thereby preventing the motion of the arm, without wasting or lowering the
pressure of the steam in the boiler, as well as to regulate the speed of the arm
by allowing more or less steam to pass through it; and I do attach another
arm of equal weight with that first ascribed in an opposite direction from the
center of motion to equalize the centrifugal force, and also by acting as a
balance to avoid the great friction which would otherwise take place between
the barrel and the supporting collar. I do also construct this improvement
with two or more arms, having similar perforations and apertures for the steam
with the arm first above described, and I do, when more convenient, place the
axis of revolution horizontal, or even inclined, instead of vertical; and I do
sometimes make the communication from the steam pipe into the middle of
the supporting collar, and from thence into the barrel, thro' a hole in that part
which turns in the collar, making a grove round the inside of the collar oppo-
site to the hole in the barrel, or a groove round the barrel opposite to the hole
in the collar, in order to allow the steam free passage during the whole of the
revolution; and I do make the aperture through which the steam is to spout
capable of being increased or decreased in its dimensions by means of a sliding
piece, marked with a screw, in order to apportion the size of the aperture to

page_text: the strength of the steam, the size of the boiler, and the work to be performed.
In cases where great speed is required the revolving arms should be made
short, and applied immediately on the axis of motion, without the usual
intervention of multiplying wheels. It is unnecessary to mention any
more variation of the mode of carrying this second part of my Invention
into effect, since I claim as my Invention the various forms of causing
steam of a high pressure to pass from a boiler through one or more perforated
revolving arms, and to spout out against the atmosphere from an aperture at the
side near the extremity of the arm or arms.
The third part of my Invention consists in causing steam of a high tempera-
ture to act upon water, and that water to operate upon or under a piston, without
permitting the steam to come in contact with the piston; by this contrivance,
also, I obviate the necessity of that tight packing which is required when steam
of a high temperature acts immediately on a piston. To effect this purpose
I use two vessels, standing side by side, which, for the sake of bearing high
pressure, I make of a cylindric form, closed at the bottom, but connected at
the lower part by a tube. One of these cylinders, which I call the steam
vessel, has a close cover, into which are inserted a steam pipe and a dis-
charging pipe, and in each pipe there is a valve or cock. The other vessel,
which I call the piston cylinder, is furnished with a piston, the rod of which
may be attached to a pump or other machinery. To put this apparatus into
operation the piston is to be placed in and near the bottom of the piston
cylinder, and the steam vessel filled with water; then, the discharging valve
being shut, and the steam valve opened, the steam will pass on the surface
of the water, or upon a piece of cork or other substance floating on the surface,
and by that pressure force the water down to the lower part of the vessel,
through the tube, into the bottom of the piston cylinder, and drive up the
piston, without admitting any steam to pass out of the steam vessel into the
piston cylinder. As soon as the steam has arrived near the orifice of the tube
the steam valve is to be shut and the discharging valve opened; the steam
will then escape through the discharging pipe, and allow the piston to
descend by its own weight, and drive the water back again into the steam
vessel, and by that means make a complete stroke, which may be repeated as
often and with as much force as the size and construction of the boiler will
supply the requisite quantity of steam. By the alternate passage of the same
water from one cylinder to the other the water may be kept nearly to boiling
heat, and, consequently, there will be no considerable condensation of the
steam on its coming in contact with the water; and, if the little condensation
which will take place should add to the quantity of water in the vessel, that

page_text: extra quantity may be ejected at every stroke through a pipe and regulating
cock communicating with the piston cylinder. A double engine is to be
constructed by using two steam vessels, with their valves, to force water alter-
nately on each side of the piston, in which case the piston cylinder must be
closed at the top, and the piston rod worked through a stuffing box, in the
usual way; or the steam vessels may be applied to. force water alternately
under two single pistons, working in cylinders open at the top, to produce the
effect of a double engine. And I do further declare that this part of my said
Invention is not capable of being used with a condensor, because the water
in the steam vessel would, if exposed to a vacuum, evaporate into the con-
densor, and destroy the vacuum. By lengthening the pipe of communication
between the steam vessel and piston cylinder the power of this engine may
be conveyed to a great distance from the boiler, without. intermediate beams
or connecting shafts. And I do further declare that, although I have described
this part of my said Invention as acting with a piston in the piston cylinder,
I sometimes use the plunger pole, working through a double stuffing box
instead of a piston.
The fourth part of my said Invention consists in interposing the steam
vessel of the third part between the boiler and revolving arms described in
the second part, so that, instead of the steam passing into the revolving arms,
it shall pass on the surface of the water in the steam vessel, and force the
water through the arms and out at the apertures near their extremities against
the atmosphere, and produce the revolution of the arms with more or less
velocity, according to the strength of the steam; in this case, also, when the
steam has forced nearly all the water out of the vessel the steam valve must
be shut and the discharging valve opened for the steam to escape, and at the
same time another valve or cock opened for the purpose of letting a fresh
portion of water from a reservoir into the steam vessel, when the steam is
again. to be admitted from the boiler, in order to force the water through the
revolving arm or arms. The arms should be inclosed in a case, to prevent the
steam or water being thrown at a distance, to the annoyance of the bystanders,
the bottom of which case may become the reservoir for supplying water to the
boiler and steam vessel. The top of the steam vessel should be placed at a
lower level than the bottom of the reservoir, in order that the water may flow
into the steam vessel when the communication from the boiler is cut off and
the steam discharged. Various modes of opening and shutting the cocks or
valves are so commonly known to all persons conversant with steam engines
that a description of them is quite unnecessary. This fourth part of my said
Invention is in some respects similar to the contrivance described in many

page_text: books or machines by the name of Barker's Mill; but in Barker's Mill no greater
power can be obtained than what arises from the perpendicular altitude of the
reservoir or head of water above the place where it spouts out from the
revolving arms, whereas in my Invention the water being acted upon and
driven out by steam of a high pressure, which is well known to pass through
tubes with very little friction compared with water, that a much greater power
will be obtained from the same quantity of water; and as the water, after it
has passed through the revolving arms, may be made to flow back again into
the steam vessel, to be driven through the revolving arms by a succeeding
portion of steam, a small quantity of water may be made to work the engine
a long time. By putting flat plates or leaves upon the revolving arms within
the case I produce a current of air in the manner of a winnowing machine
for blowing the fire, and I do sometimes place in the flue a screw or set
of vanes, somewhat similar to the vanes of a smoak jack, which screw
or vane I do cause to revolve, by connection with the steam engine, for the
purpose of creating an artificial draft in the chimney, always proportioned to
the size of the fire-place and situation of the chimney. By either or both of
these means I obviate the necessity of a tall chimney when the engine is
used for portable purposes.
The fifth part of my said Invention, and that which comes under the second
part of my title, consists of a mode of propelling, drawing, or causing, ships,
boats, and other vessels to pass through the water, which purpose I effect by
constructing a worm or screw, or a number of leaves placed obliquely round
an axis, similar to the vanes of a smoke jack, which worm, screw, or vane
shall be made to revolve with great speed, having the axis in a line with
the required motion of the ship, boat, or other vessel, or parellel to the same
line of motion; the obliquely of the thread of the worm, screw, or leaves admits
of considerable variety, according to the degree of velocity given to it and
speed required, and according to the power with which it is driven, but as a
general medium I by preference contrive that the thread of the screw at its
outer edge shall make with its axis an angle of about thirty degrees. This
worm is in some cases to revolve in a fixed cylinder, in others to revolve
together with the cylinder, similar to the screw of Archimedes, but generally
to revolve in the water without any cylinder surrounding it. This woim or
screw may be made to revolve in the water at the head of the ship, boat, or other
vessel, or at the stern, or one or more worms may revolve on each side of the
vessel, as may most conveniently suit the peculiar navigation on which the
ship, boat, or vessel is to be employed. In some cases when the s crew is to
work at the head of a ship it is to be made buoyant, and move on a universal

page_text: joint, at the end of an axle, turning in the bow of the ship, in order that the
screw may accommodate itself to the uneveness of the waves. And I do further
declare that, in order to make the boiler of a high-pressure steam engine of
very light materials for portable purposes, and at the same time strong for
resisting the pressure, as well as for exposing a large surface to the fire, I
do construct the said boiler of a number of small perpendicular tubes, each
tube closed at the bottom, but all opening at the top into a common reservoir,
from whence they receive their water, and into which the steam of all the