IMPROVED MEANS OF AND APPARATUSES FOR CREATING OR INCREASING DRAUGHTS AND CURRENTS
Year: 1857

page_text: LETTERS PATENT to William Petrie, of Woolwich, in the County of
Kent, Civil Engineer, for the Invention of "IMPROVED MEANS OF AND
APPARATUSES FOR CREATING OR INCREASING DRAUGHTS AND CURRENTS."
Sealed the 3rd September 1857, and dated the 6th March 1857.
PROVISIONAL SPECIFICATION left by the said William Petrie at the
Office of the Commissioners of Patents, with his Petition, on the 6th
March 1857.
I, WILLIAM PETRIE, of Woolwich, in the County of Kent, Civil Engineer,
do hereby declare the nature of the said Invention for "IMPROVED MEANS
OP AND APPARATUSES FOR CREATING OR INCREASING DRAUGHTS AND CURRENTS," to
be as follows:
1st.. To increase the power of an existing draught I make use of a series of
vene contracta, that is to say, the end of a vent pipe is made as small as will
admit gases or air to pass without materially checking the draught, and is
inserted concentrically. into a short pipe, called a vena contracta, being
gradually contracted from each end towards its middle, where the end of the
vent pipe is fixed. This vena contracta is similarly..inserted into another of
larger dimensions, and so the series may be increased, and the largest pipo
which encloses all the others is fixed. into the side of a chimney, or applied
to whatever draught is available, which is in this way made to produce a
greatly increased force of draught at the vent pipe.
This apparatus is applicable to a variety of purposes, hydraulic as well as

page_text: pneumatic, and with outward as well as inward draught may be used to
increase the draught of a furnace which may be required more powerful than
others connected with the same chimney. I also apply this apparatus in a
reversed manner to increase the force of wind, or of a blast of air from any
source, wherever such increased blast may be needed. I also apply a similar
apparatus to hydraulic purposes, either in the first-mentioned manner, for
suction to draw up water from a lower level by means of the flow of a
stream at a higher level, for instance, to drain a marsh below the level of an
adjacent river or sea, by the flow of the river or by the tide of the sea flow-
ing into and out of a reservoir; the action of the apparatus being stopt by
sluices, or by a valve in the suction pipe, whenever the flow of water becomes
too gentle to produce the action. Or else I apply the apparatus in a reversed
manner to make the velocity of a stream or flow of water force up a portion
of its own water to a higher level than the head of water, which causes the
velocity of the stream.
In any of these applications the venæ contractæ and pipes may be very
much modified in form, square or round, &c. in section, and contracted in
one direction only, instead of, as I prefer, in both dimensions of their cross
section.
2nd. I encrease an existing draught by means of what I call a pneumatic
ram. This consists of a large pipe, preferred to be straight, having one end
connected with the chimney,, or whatever tho available means of draught
may be, and the other end trumpet-mouthed, having a very light valve hung
so as to cover it, and to open outwards, and so balanced by a weight placed
close to the hinge as that the draught shall cause it to beat continuously.
Close to this end of the pipe there is a valve, which I prefer to make in
its under side, and in the following manner:-A number of holes are made
in the pipe, and over them a thin sheet of vulcanized caoutchouc is fastened
by its opposite ends, so as to form an air-proof valve, and a perforated plate
is fixed over it, so close to it as not to let it rise further from the holes than
is useful to allow the air to pass moderately freely into the pipe. These holes
communicate with a largo air vessel. The action of the ram will cause the
air to be drawn with greatly multiplied force out of the air vessel.
This apparatus is applicable to a variety of other pneumatic purposes, liko
the vena contracts, but is more powerful, and to use it in a reversed manner S
to produce an outward blast from the air vessel instead of an inward suction
it is only necessary to make the air enter the pipe where I have previously
stated it leaves it, and to put the trumpet-mouth at that end, and to reverse
.g

page_text: the action of the two valves. This apparatus may be constructed with a
great variety of modifications without altering the essential properties of this
part of my Invention.
To produce a draught of inward suction I use an hydraulic suction wheel,
that is to say, a hollow cylinder closed at the ends, with an inner cylinder
fixed concentrically, and a hollow spindle fixed throngh it, and revolving
horizontally in bearings at each end of it. This drum is partially immersed
in a tank of water, on the sides of which the bearings of the spindle may be
fixed. One end of this spindle is made to revolve accurately in the end of
a fixed pipe. The other end of the spindle is closed, and may be coupled
with the axis of a waterwheel or any other source of power to make the
cylinder revolve. Divisions, three being preferred, are placed between the
inner and outer cylinder at right angles to the planes of its ends. Valves
opening outwards are fixed over holes in the inner and outer cylinders close
to each division, and those in the outer cylinder are so balanced by weights
attached to their inner sides that they shall closo just before they rise above
the surface of the water, and they are not allowed to open further than is
necessary to admit the water freely into the outer cylinder. Holes are made
throughout the length of the outer cylinder close to each of the divisions on
the opposite sides of them to where the valves are placed. Hollow blocks are
fixed throughout the length of the outer cylinder merely to displace the water
in that part where its presence would cause loss of power, and a disturbance
when that part left the surface of the water. The apparatus being thus
formed, air will be drawn from the pipe connected with the hollow spindle,
while the wheel is made slowly to revolve, as described, and the force of the
suction will be in proportion to the radius of the inner cylinder, provided
there be sufficient power to turn the wheel in all cases.
This apparatus may be used to produce an outward draught or blast by
carrying up the sides of the tank and adding a top, so as to enclose the wheel
air-tight, and connecting a pipe-from the upper part of this tank, from which
the blast will como, the open end of the axis being left free in the air, and
the wheel being turned in the same direction as before. This apparatus may
thus be used for various purposes where a draught either of pressure or of
suction is required.
Another means which I employ to produce a draught is as follows:-I take '
a hollow wheel or cylinder closed at the ends; and fixed to a shaft revolving'
horizontally in bearings, and through which bearings any moving power cau"
be applied to it. Around the periphery of this wheel are fixed recesses in the

page_text: he action of the two valves. This apparatus may be constructed with a
reat variety of modifications without altering the essential properties of this
art of my Invention...
To produce a draught of inward suction I use an hydraulic suction wheel,
hat is to say, a hollow cylinder closed at the ends, with an inner cylinder
ixed concentrically, and a hollow spindle fixed through it, and revolving
orizontally in bearings at each end of it. This drum is partially immersed
na tank of water, on the sides of which the bearings of the spindle may be
ixed. One end of this spindle is made to revolve accurately in the end of
a fixed pipe. The other end of the spindle is closed, and may be coupled
with the axis of a waterwheel or any other source of power to make the
cylinder revolve. Divisions, three being preferred, are placed between the
inner and outer cylinder at right angles to the planes of its ends. Valves
opening outwards are fixed over holes in the inner and outer cylinders close
to each division, and those in the outer cylinder are so balanced by weights
attached to their inner sides that they shall close just before they rise above
the surface of the water, and they are not allowed to open further than is
necessary to admit the water freely into the outer cylinder. Holes are made
throughout the length of the outer cylinder close to each of the divisions on
the opposite sides of them to where the valves are placed. Hollow blocks are
fixed throughout the length of the outer cylinder merely to displace the water
in that part where its presence would cause loss of power, and a disturbance
when that part left the surface of the water. The apparatus being thus
formed, air will be drawn from the pipe connected with the hollow spindle,
while the wheel is made slowly to revolve, as described, and the force of the
suction will be in proportion to the radius of the inner cylinder, provide
there be sufficient power to turn the wheel in all cases.
This apparatus may be used to produce an outward draught or blast by
carrying up the sides of the tank and adding a top, so as to enclose the wheel
air-tight, and connecting a pipe from the upper part of this tank, from which
the blast will come, the open end of the axis being left free in the air, and
the wheel being turned in the same direction as before. This apparatus may
thus be used for various purposes where a draught either of
suction is required.
pressure
or of
Another means which I employ to produce a draught is as follows:-I take
a hollow wheel or cylinder closed at the ends; and fixed to a shaft revolving
horizontally in bearings, and through which bearings any moving power can
be applied to it. Around the periphery of this wheel are fixed recesses in the

page_text: manner of an ordinary waterwheel. This wheel is fixed in an air and water-
tight case, which is filled with water up to the top of the cylinder. At the
ascending side of the wheel an air chamber, open at the bottom, is formed in
the case, with its under edge projecting, so as to stand close to the periphery
of the wheel nearly as low as its under side, so as to receive the air which
is liberated from the recesses as each of them passes the lowest position.
In the top of this air chamber an outlet pipe is fixed, and in the top of the
case an inlet pipe, and the end of the pipe in which the draught of suction
is to be produced is attached to the inlet pipe, the other pipe being left
open to the atmosphere, or otherwise suitably connected with any desired
apparatus.
This apparatus may be used for various purposes where a draught is
required.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said William Petrie in the Great Seal Patent Office on the
5th September 1857.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
PETRIE, of Woolwich, in the County of Kent, Civil Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Sixth day of March, in the year of our Lord
One thousand eight hundred and fifty-seven, in the twentieth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me,
tho said William Petrie, Her special licence that I, the said William Petrie,
my executors, administrators, and assigns, or such others as I, the said William
Petric, my executors, administrators, and assigns, should at any time agree
with, and no others, from time to time and at all times thereafter during
the term therein expressed, should and lawfully might make, use, exercise,
and vend, within the United Kingdom of Great Britain and Ireland, the
Channel Islands, and Isle of Man, an Invention for "IMPROVED MEANS OF
AND APPARATUSES FOR CREATING OR INCREASING DRAUGHTS AND CURRENTS," upon
the condition (amongst others) that I, the said William Petrie, my executors
or administrators, by an instrument in writing under my, or their, or one
of their hands and seals, should particularly describe and ascertain the
nature of the said Invention, and in what manner the same was to be
performed, and cause the same to be filed in the Great Seal Patent Office 3

page_text: within six calendar months next and immediately after the date or
Letters Patent.
LEG SHI
NOW KNOW YE, that I, the said William Petrie, do hereby declare
he nature of my said Invention, and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following
statement thereof, reference being had to the Drawings hereunto annexed,
that is to say:-
First. To increase the power of an existing draught I make use of a series
of venue contracte, Figure 1, that is to say, the end of the pipe A from which
a suction draught is required is made as small as will admit gases or air to
pass without materially checking the draught, and is inserted concentrically
into a short pipe B, called a vena contracta, being gradually contracted from
each end towards its middle. I prefer to make a short portion of the middle
of the pipe uniform in bore, and to make the section of the contracted part
to be a curve of contrary flexure, as shewn in the Drawing, which gives
also what I consider to be generally the best proportions. The end of the
previous pipe A is inserted into the next pipe B as far as the commencement
of its narrowest part. This vena contrata B is similarly inserted into another
of larger dimensions C, and so the series may be increased, and the largest pipe,
which encloses all the others, is fixed into the side of a chimney D, or applied
to whatever draught is available, which is in this way made to produce a
greatly increased force of draught at the first pipe A.
This apparatus is applicable to a variety of purposes, hydraulic as well as
pneumatic, and with outward as well as inward draught. For instance, it
I may be used to increase the draught of a furnace which may be required
more powerful than others connected with the same chimney. I also apply
this apparatus in a reversed manner to increase the force of wind, or of a
blast of air from any source, wherever such increased blast may be needed.
I also apply a similar apparatus to hydraulic purposes, either in the first-
mentioned manner for suction to draw up water from a lower level by means
of the flow of a stream at a higher level, for instance, to drain a marsh below
the level of an adjacent river or sea, by the flow of the river or by the tide of
the sea flowing into and out of a reservoir; the action of the apparatus being
stopped by sluices, or by a valve in the suction pipe A, whenever the flow of
5 water becomes too gentle to produce the action. Or I apply the apparatus in
a reversed manner to make the velocity of a stream or flow of water force up
a portion of its own water to a higher level than the head of water which
causes the velocity of the stream.

page_text: in any of these applications the venæ contract and pipes may be ver
much modified in form, square or round, &c. in section, and contracted i
one direction only, instead of, as I prefer, in both directions of their cros
section.
This apparatus is remarkable for the advantage of working without any
moving parts, a desideratum well understood by mechanicians.
Second. I increase an existing draught, especially in cases where the vena
contracte would not be adequate, by means of what I call a pneumatic ram
Figure 2. This consists of a large pipe E, preferred to be straight, having onc
end connected with the chimney, or whatever the available means of draught
may be, and the other end trumpet-mouthed, having a very light valve F hung
so as to cover it and to open outwards, and so balanced by a weight f, placed
close to the hinge, as that the draught shall cause it to beat continuously. Close
to this end of the pipe E there is a valve, which I prefer to make in its under
side, and in the following manner :-A number of holes G, G, G, are made in
the pipe, and over them a thin sheet of vulcanized caoutchouc is fastened by
its opposite ends, so as to form an air-proof valve, and a perforated plate H, H,
is fixed over it, so close to it as not to let it rise further from the holes than
is useful to allow the air to pass moderately freely into the pipe. These holes
communicate with a large air vessel I. The ram is to be set working by open-
ing the large valve and then letting it go, and it works on the same principle
as the well-known engine, called the hydraulic ram, used for forcing water.
The action of the ram will cause the air to be drawn with greatly multiplied
force out of the air vessel, which by the elasticity of the air within it serves to
equalize the intermittent suction of the ram.. The pipe from which the force
of suction is required is connected with this air vessel I. A very suitable
length for the pipe is one thousand times the height which, the available
draught will raise water.
This apparatus is applicable to many pneumatic purposes, like the venæ
contract, but is moro powerful, and does not need proportionably so large a s
flow of air of the feeble draught which actuates it. To use it in a reversed
manner to produce an outward blast from the air vessel instead of an inward
suction, it is only necessary to make the air to enter the pipe at the opposite
end and to put the trumpet-mouth at that end and to reverse the action of the
two valves.
This apparatus may be constructed with a great variety of modifications
without altering the essential properties of this
part of
my Invention.
Third. To produce draught equally or more powerful than by the preceding
3

page_text: apparatus, and where no feebler draught is to be made use of, I employ what I
erin the "trochoid air bell," or endless chamber, Figure 3, that is to say, a
hollow cylinder K, K, closed at the ends with an inner cylinder L, L, fixed
concentrically, and a hollow spindle M fixed through it, and revolving hori-
zontally in bearings at each end of it. This drun is partially immersed in a
tank of water N, N, on the sides of which the bearings of the spindle may be.
fixed. One end of this spindle is made to revolve accurately in the end of a
fixed pipe from which it is intended to draw air or gases, and there are holes
in the sides of that part of the hollow axis M which is within the drum,.
whereby the air can pass freely into the inner cylinder L, L. The other end of
the spindle is closed, and may be coupled with the axis of a waterwheel, or
any other source of power, to make the cylinder revolve in the direction shewn
by the arrows. Divisions 0, 0, two being preferred, are placed between the
inner and outer cylinder at right angles to the planes of its ends, and of the
form and in the position shewn in the Drawing. Valves P, P, opening out-
wards are fixed over holes in the inner cylinder L, L, close to each division, in
the manner shewn. There are longitudinal openings Q, Q, down the length of
the outer cylinder in the position shewn in the Drawing relative to the divisions
0, 0, with valves R, R, so arranged, that in one position of either of these
valves it closes air-tight the space that is left between the edge of the division
O, O, and the outer cylinder, and leaves a free passage for the water and air
from the foremost side of the division within the cylinder to the exterior of
the cylinder. I call the sides of the divisions foremost and hindmost, accord-
ing to the direction of the motion around the axis. Each of the valves when
in their other position closes the opening Q, but not necessarily air or water
tight, and opens a free passage for water and air from the foremost to the
hindmost side of the division. The valves R, R, have each a boss or arm S, S,
projecting from the outer side through the opening Q, which arm meets a
spring T, so fixed in the tank as to close the valve R (by the revolution of
the drum bringing the arm S against the spring) just before the opening Q
rises above the surface of the water in the tank, and when this takes place
the valve on the opposite side of the drum falls open by the pressure, thereby
being made as great on its hind most side as on its foremost side. The
valves are shewn in the Drawing so formed and placed that the force
of gravity aids the reversal of their positions at the proper moment, and tho
retention of them in their proper positions at all parts of their revolution.
The length of the drum may be increased according to the quantity of air to
be drawn through it per minute; but I prefer to make its length to be from

page_text: quarter to the whole of its diameter. The apparatus being thus formed, an
the drum being made to rotate in the direction shewn by the arrows, air wil
be drawn from the pipe connected with the hollow spindle, while the wheel i
made slowly to revolve, as described, and the force of the suction will be in
proportion to the radius of the inner cylinder, provided there be sufficien
power to turn the wheel in all cases.
This apparatus may be used to produce an outward draught or blast by
carrying up the sides of the tank and adding a top, so as to enclose the wheel
air-tight, and connecting a pipe from the upper part of this tank, from which
the blast will come, the open end of the axis being left free in the air, and the
wheel being turned in the same direction as before. This apparatus may thus
be used for various purposes.
Fourthly, where a greater force of draught is desired with a given quantity
of air moved per minute, than the preceding apparatus will conveniently fur-
nish, or where the valves aro objectionable, I employ what I term a hydro-
pneumatic wheel, Figures 4 and 5, that is to say, a hollow wheel or cylinder
U, U, closed at the ends, and fixed to a shaft revolving horizontally in bearings
in the direction shown by the arrows, and through the shaft, any moving power
can be applied to the wheel. Around the periphery of this whicel aro fixed
recesses V, V, V, in the manner of an ordinary waterwheel, but of such form
(as shewn in Figure 4) that they shall enclose portions of the gas in the upper
part of the case and carry them down through the liquid and liberate them
below into an air chamber. This wheel is fixed in an air and water tight
case W, W, which is filled with water up to the top of the cylinder U. At
the ascending side of the wheel an air chamber X, open at the bottom, is
formed in the case W; and I consider the following to be a good mode for
preventing loss of air through bad fitting of the parts. The division, which
forms the side of the air chamber next to the wheel, has its lower edge Y
connected with it by a strip of leather Z, rivetted to each throughout the
length of the air chamber, and so forming a flexible air and water tight s
joint. This flexible lower edge Y projects towards and touches the periphery
of the wheel through its length at nearly as low a level as the under sido
of the inner cylinder U, so as to receive the air which is liberated from the
recesses V, V, V, as each of them passes the lowest position. Several springs T
are fastened by one end to the bottom of the tank, and by the other end 3
to the lower edge Y, so as to retain it in its position and keep it gently
but closely against the wheel. In the top of the case W an inlet pipe A is
fixed, and the end of the pipe in which the draught of suction is to be pro-

page_text: duced is attached to this, or otherwise. The top of the air chamber X may
also be covered over if desired, and the gases or air arising from it may then
be led by a pipe to any desired apparatus or place. I prefer to make the
discharge of the gas or air more gradual and uniform by having the wheel
5 divided (transversely to its axis) by partitions into about three separate lengths,
so as to make it, in fact, like three distinct wheels fixed rigidly on the same
shaft, each successively having the lead of its neighbour (to the extent of
twenty degrees in the example shewn in the Drawings), so that there shall bo
equal intervals of time betwen the discharges of air from the various recesses
V, V. Figure 5 shews this, as it gives a view of the wheel from above:
Figure 5 also shews the shaft and its bearing in section at that end where tho
shaft comes through the case W. The shaft is preferred to be conical in its
bearing, so that it can be made to fit water and air tight by pressing the shaft
in by means of suitable screw bolts with check nuts, as is well understood by
mechanicians. I have hitherto spoken of water only as the liquid in which
either this wheel or the trochoid air bell is to work, but any other liquid may
be used which the cirumstances or the nature of the gas may render desirable;
for instance, where gases are employed which would act injuriously on the
material of the moving parts of the apparatus an oily liquid may be used
instead of water, or where a vacuum or great compression of the, gas is wanted;
or a great force of draught mercury may be used, also where the gases are to
be preserved in a dry state. Liquids also may be impelled instead of air or
gases by either of my two latter machines, provided the liquids impelled be
lighter than the other liquid used and not disposed to mingle with it.
The outer cases also of the two last-named apparatus may be furnished with
glass or other gauges, or plate glass windows, to shew the action within, and the
height of the liquid, which may be regulated by a tap at bottom and one at top
to admit more liquid when needed.
And having now described the nature of my said Invention, and in what
manner the same is to be performed, I declare that I claim,-
First, the means of and apparatus for creating draughts and currents, as
described under the first head of this my Specification.
Second, the employment of a series of two or more such apparatuses in
order to multiply or increase the effect thereof.
Third, the employment of the pneumatic ram for the purposes and in
manner described under the second head of this Specification.
Fourth, the employment of a revolving wheel or drum partially filled with
a liquid and fitted up with compartments and self-acting valves so as to act

page_text: in manner and for the purposes herein-before described under the third head
hereof.
And, fifth, the employment of a revolving wheel or drum with recesses as
described, and mounted in a closed case containing liquid, and fitted up, for the
purposes and in the manner heroin-before described under the fourth head of
this my Specification.
In witness whereof, I, tho said William Petrie, have hereunto set my
hand and seal, this Fifth day of September, One thousand eight hundred
and fifty-seven.
WILLIAM PETRIE. (L.S.)