IMPROVEMENTS IN ARRANGEMENTS AND APPARATUS FOR TREATING SMOKE, GASES, VAPOURS, AND NOXIOUS GASEOUS DISCHARGES FROM FIRES, FURNACES, CHEMICAL, SEWAGE, MANURE, AND OTHER WORKS OR MANUFACTORIES, AND UTILIZING THE PRODUCTS THERE- FROM, PARTS OF WHICH IMPROVEMENTS ARE ALSO APPLICABLE TO THE MANG- FACTURE OF GAS AND FOR COOLING AND PURIFYING AIR FOR VENTILATING BUILDINGS AND MINES
Year: 1878

page_text: LETTERS PATENT to John Smethurst, of Clifton, in the County of Lancaster,
Mining Engineer, for the Invention of IMPROVEMENTS IN ARRANGEMENTS
AND APPARATUS FOR TREATING SMOKE, GASES, VAPOURS, AND NOXIOUS
GASEOUS DISCHARGES FROM FIRES, FURNACES, CHEMICAL, SEWAGE, MANURE,
AND OTHER WORKS OR MANUFACTORIES, AND UTILIZING THE PRODUCTS THERE-
FROM, PARTS OF WHICH IMPROVEMENTS ARE ALSO APPLICABLE TO THE MANG-
FACTURE OF GAS AND FOR COOLING AND PURIFYING AIR FOR VENTILATING
BUILDINGS AND MINES."
Sealed the 1st October 1878, and dated the 6th July 1878.
PROVISIONAL SPECIFICATION left by the said John Smethurst at the
Office of the Commissioners of Patents on the 6th July 1878.
JOHN SMETHURST, of Clifton, in the County of Lancaster, Mining Engineer.
IMPROVEMENTS IN ARRANGEMENTS AND APPARATUS FOR TREATING SMOKE, GASES:
VAFOURS, AND NOXIOUS GASEOUS DISCHARGES FROM FIRES, FURNACES, CHEMICAL,
SEWAGE, MANURE, AND OTHER WORKS OR MANUFACTORIES; AND UTILIZING THE
PRODUCTS THIEREFROM, PARTS OF WHICH IMPROVEMENTS ARE ALSO APPLICABLE TO
THE MANUFACTURE OF CEAS AND FOR COOLING AND PURIFYING AIR FOR VENTI-
LATING BUILDINGS AND MINES."
!
My Invention consists in arrangements for treating the products of combustion
from fires, and furnaces and noxious gaseous discharges, from chemical sewage,
manure, and other works and manufactories, by collecting or forcing the same into
or driving the same by fans, pumps, rotary drums, or other suitable means through
or under water, or water and lime, or water and manganese,. or some other suitable
liquid or other material (depending upon the character of the gases to be treated),
and causing such gases to be divided into very numerous jets so as to ascend in
D
071

page_text: fine bubbles or atoms through the water or mixture of water and other material
employed to the surface thereof, this operation being repeated more than once, if
required, so that the gases so treated are discharged by the chimney or other outlet
into the atmosphere in a purified and innoxious condition.
The water or mixture employed as it gets loaded or cliarged with the products
left by the passing gases is drawn off into a tank or reservoir, and a fresh supply
is given, or the impure or loaded water or mixture is continually drawn off and a
fresh supply is continually added.
The liquid drawn off into the tank or reservoir is treated with lime or other
suitable material, and the solid matter is allowed to settle and the clear and purified
water is drawn off and used again or discharged.
In applying my mode of treatment to the products of combustion from furnaces,
the apparatus employed for drawing or forcing the gases through the purifying
liquid also acts to create the draught for supplying air to the fire or furnace for
combustion, and thus the heat which is usually and necessarily wasted in the
chimney to create a draught is and may be economized by causing the heated
products of combustion before arriving at the purifying arrangement to pass in
contact with apparatus known as an economizer," cold water being forced into
this economizer" at the end furthest from the furnace, and the heated water from
this economizer is passed on by pumping to the next economizer. The heat thus
saved is sufficient, at least when converted into steam, to give the power required
for working the apparatus (pumps, fans, or other mechanism) for forcing or drawing
the products of combustion through the purifying apparatus.
"
The mechanism and apparatus which, according to my present experience, I
prefer to employ, and in which part of my Invention consists, to draw or force the
gases is to some extent upon the principle of a water gas meter, except that the
action is reversed, power being applied to drive or rotate the drum corresponding
to the measuring drum of the gas meter, so as to take the gases in from the chamber
above the water line at the circumference of the drum, and force, draw, or convey
them towards its centre where they are discharged through the hollow tubular
axis, and the water in each compartment of the drum is also wholly or partly
discharged with the gases, which tubular axis may extend from one or both ends
of the drum, and terminate in a chamber below the water line formed with
numerous holes or with wire gauze, so as to divide the gases, so that they will
break up and ascend to the surface of the water in small bubbles or atomis.
The gases to be operated upon first enter the drum chamber, and are discharged
by the tubular axis of the drum into a separate chamber, from which they may
pass to the chimney or outlet to the atmosphere.
To render the atmosphere of towns comparatively pure, by my Invention the
Anes from all furnaces and fires are connected with, and all noxious gaseous dis-
charges are conveyed into sewers or flues, so as to be collected together and
treated, as above described, to purify them before being allowed to pass into the
atmosphere.
:
My Invention also consists in applying the pumping or forcing apparatus above
described for exhausting the gas from retorts and relieving the retort from pressure,
and washing and purifying the gas by passing it through water, or lime water, or
chloride of manganese, or other suitable mixture. In this case, the hydraulic seal
between the gas retort and the main may, if desired, be dispensed with, and a valve
substituted, opened or closed, self acting (if desired) by connection with the lid of
the retort, so that the valve is closed when the lid is open, and vice versa..
My Invention also consists in supplying coal and purified air for the ventilation
of buildings and mines by the apparatus above described or other suitable means,
the air being drawn or forced through the water or other mixture, if requisite, to
further reduce the temperature, and is thus cooled and purified at the same time
and then conveyed into buildings or mines to be supplied.
For ventilating and cooling mines and freeing them from gases my Invention

page_text: consists in arrangements, combined with the propelling or exhausting machinery
by which the pressure of the atmosphere in mines may be reduced when the men
are not working to allow the gases to escape more freely and afterwards allowed
to attain its full pressure before the work begins, and this I accomplish by closing
or partly closing the "down-cast shaft" or passages while the exhaust is continued
in the up-cast shaft or passages, and afterwards opening the "down-cast shaft"
or passages.
I also cause jets of water at high pressure to be dispersed in the
air in various parts of the mine, to further assist in cooling the air and laying the
dust.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said John Smethurst in the Great Seal Patent Office on the 2nd
January 1879.
.
JOHN SMETHURST, of Clifton, in the County of Lancaster, Mining Engineer.
"IMPROVEMENTS IN ARRANGEMENTS AND APPARATUS FOR TREATING SMOKE, GASES,
VAPOURS, AND NOXIOUS GASEOUS DISCHARGES FROM FIRES, FURNACES, CHEMICAL,
SEWAGE, MANURE, AND OTHER WORKS OR MANUFACTORIES, AND UTILIZING THE
PRODUCTS THEREFROM, PARTS OF WHICH IMPROVEMENTS ARE ALSO APPLICABLE TO
THE MANUFACTURE OF GAS AND FOR COOLING AND PURIFYING AIR FOR VENTI-
LATING BUILDINGS AND MINES."
My Invention consists in arrangements for treating the products of combustion
from fires and furnaces, and noxious gaseous discharges from chemical, sewage,
manure, and other works and manufactories, by collecting and forcing the same
into or driving the same by fans, pumps, rotary drums, or other suitable means,
through or under water, or water and lime, or water or some other suitable liquid
or other material (depending upon the character of the gases to be treated), and
causing such gases to be divided into very numerous jets, so as to ascend in fine
bubbles or atoms through the water or mixture of water and other material
employed to the surface thereof, this operation being repeated more than once if
required, so that the gases so treated are discharged by the chimney or other outlet
into the atmosphere in a purified and innoxious condition.
The water or mixture employed, as it gets loaded or charged with the products
left by the passing gases is drawn off into a tank or reservoir and a fresh supply
is given, or the impure or loaded water or mixture is continually drawn off and a
fresh supply is continually added.
The liquid drawn off into the tank or reservoir is or may be treated with lime
or other suitable material, and the solid matter is allowed to settle, and the clear
and purified water is drawn off and used again or discharged.
In applying my mode of treatment to the products of combustion from furnaces,
the apparatus employed for drawing or forcing the gases through the purifying
liquid also acts to create the draught for supplying air to the fire or furnace for
combustion, and thus the heat which is usually and necessarily wasted in the
chimney to create a draught is and may be economized by causing the heated
products of combustion before arriving at the purifying arrangement to pass in
contact with apparatus known as an economizer, cold water being forced into
this economizer at the end furthest from the furnace, and the heated water from
this economizer is passed on to the next economizer by pumping or otherwise.
The heat thus saved is applicable wholly or in part, at least when converted into
steam, to give the power required for working the apparatus (pumps, fans, or other
mechanism) for forcing or drawing the products of conibustion through the purifying
apparatus.
6.
"
The mechanism and apparatus which, according to my present experience. I
prefer to employ, and in which part of my Invention consists, to draw or force the
gases, is to some extent upon the principle of a water gas meter, except that the
action is reversed, power being applied to drive or rotate the drum corresponding
to the measuring drum of the gas meter, so as to take the gases in from the
chamber above the water line at the circumference of the drum, and force, draw, or
convey them towards its centre, where they are discharged through the hollow
tubular axis, and the water in each compartment of the drum is also wholly or
partly discharged with the gases, which tubular axis may extend from one or both
ends of the drum and terminate in a chamber below the water-line formed with
numerous holes or with wire gauze, so as to divide the gases, so that they will
break up and ascend to the surface of the water in small bubbles or atoms.
The gases to be operated upon first enter the drum chamber, and are discharged

page_text: by the tubular axis of the drum into a separate chamber from which they may pass
to the chimney or outlet to the atmosphere.
:
To render the atmosphere of towns comparatively pure, by my Invention, the
town is divided into districts, and the flues from all furnaces and fires in the
district are connected with, and all noxious gaseous discharges are conveyed into
sewers or flues, so as to be collected together and treated as above described, to
purify them before being allowed to pass into the atmosphere.
My Invention also consists in applying the pumping or forcing apparatus above
described, or a modification of it, for exhausting the gas from retorts and relieving
the retorts from pressure, and washing and purifying the gas by passing it through
water, or lime water, or other suitable mixture. In this case the hydraulic seal
between the gas retort and the main, may, if desired, be dispensed with, and a valve
substituted, opened or closed, self acting (if desired) by connection with the lid of
the retort, so that the valve is closed when the lid is open, and vice versa.
My Invention also consists in supplying cool and purified air for the ventilation
of buildings and mines by the apparatus above described or other suitable means,
the air being drawn or forced through the water or other mixture, if requisite, to
further reduce the temperature, and is thus cooled and purified at the same time,
and then conveyed into buildings or mines to be supplied.
For ventilating and cooling mines and freeing them from gases my Invention
consists in arrangements, combined with propelling or exhausting machinery, by
which the pressure of the atmosphere in mines may be reduced when the men are
not working to allow the gases to escape more freely, and afterwards allowed to
attain its full pressure before the work begins, and this I accomplish by closing or
partly closing the down-cast shaft or passages while the exhaust is continued in
the up-cast shaft or passages and afterwards opening the down-cast shaft or
passages. I also cause jets of water at high pressure to be dispersed in the air in.
various parts of the mine, to further assist in cooling the air and laying the dust.
Fig. is a cross sectional elevation, and Fig. 2 a longitudinal sectional elevation,
illustrating one arrangement of apparatus for carrying out the object of my Inven-
tion, which will be first described in reference to the purifying of the products of
the combustion of coal or other fuel for generating steam.
is the cylinder formed with two ends, and with a middle partition dividing it
into two cylindrical chambers, and at each end there is a cylindrical continuation a
which is perforated with numerous small holes, or it is constructed as a cylindrical
frame covered with wire gauze. These cylindrical projections also form the pivots
upon which the cylinder is rotated, as they rest upon two antifriction pulleys b
carried in suitable bearings. Upon the surface of the cylinder a teeth or segments a
are secured, which gear with a pinion (shown in dotted line in Fig. 1).on a shaft c
in suitable bearings, which shaft is driven by the motive power employed.
The interior of the cylinder a is divided into compartments, as shown best in
Fig. 1, and each compartment at the periphery of the cylinder has an inlet
orifice (), and has also a separate outlet a' near the axis into the cylindrical
pivots (a).
The cylinder or wheel is or may be constructed of boiler plates rivetted together..
of cast iron, or of iron and wood,. or any suitable material, as may be desired, and it
is arranged in a cistern or tank d, which may be formed as shown, by the walls of
a building having an inverted arch for its base divided into three rooms or
compartments, which a ceiled and plastered so as to be gas-tight, and are
roofed.
"
The middle chamber of the building is for the cylinder or wheel («), and this
compartment communicates with the flue or passage conveying the products of
combustion to be purified.
In the building at each end of the wheel there is a partition wall. which
separates the middle chamber from the two end chambers of the building
which communicates with a flue or passage that' conveys away the purified gases to
the chimney.

page_text: .
The lower part (7) of the building forming the tank is filled with water up to
the line e, and this water rises to the same level in each chamber (and ³) of the
building, as there are communicating passages or holes in the partition walls (d²)
below the water line c
It will be seen that when the wheel () is revolved in the direction pointed by
the arrow the compartments in it above the water line (e) which have filled with
the gaseous products of combustion will in succession be submerged, and the gases
will thus be forced through the axial passage and will escape through the per-
forations and rise through the water to the surface into the end chambers (3) of
the building, and during the time the gases are submerged the noxious gases (the
sulphurous acid gas) will be absorbed by and the soot will be left in the water, the
gases passing through a depth of say about 12 inches of water.
When the gases in the compartments of the wheel are forced out by the entering
water it remains in the compartments until they begin to ascend above the water
line, when the water in them is also discharged through the axial passage and they
fill again with gases. These cylinders of large diameter are revolved slowly to give
time for the water to escape from the axial passages, but if desired valves may be
formed in each compartment at or near the periphery of the wheel to allow the
water to be discharged through such valves, or partly through such valves and the
axial passages. Such valves are or may be placed at what will be the upper part
of the compartment when its inlet orifice is entering the water, and they are
arranged to open outwards, and are loaded to keep them closed when they are
descending by a lever and weights equal to the pressure to which the gases are
subjected (say half a pound per square inch); but when the compartments come on
the ascending side of the wheel the weighted lever tumbles over and opens the
valve, which remains open until the compartment arrives at its highest position.
when the tumbler lever again moves in the opposite direction and shuts the
valve.
In place of a lifting valve a slide valve may be employed acted upon by the
tumbler weight as above described to open and close the valve, or the tumbler lever
is or may be moved by striking or coming against projections fixed to the wall or
partition (2), one of which projections being arranged to come against one arm of
The tumbler lever to move it one way, and the other projection against another arm
of the tumbler lever on the opposite side of its fulcrum to move it the other
way.
The sooty particles at first float on the surface of the liquid and while it is agitated,
but as there is, or may be, a fresh supply of water entering the tank the surface
water carrying the floating soot passes along with the overflow into a covered
tank (f), the surface of which is kept below the water line e, and from this tank (f)
the liquid is, or may be, drawn off into a tank, where it is, or may be, allowed to
settle to the bottom, and then the water may be drawn off and used again or allowed
to escape. The soot, alone or mixed with lime (if desired), is or may be used as a
manure or for other purposes.
Sliding valves (g) are or may be used, actuated by a screw nut rotated by bevel
wheels or in any other suitable manner to withdraw the liquid from the wheel
tank (), and clear it from sediment when required.
Fig. is a cross sectional elevation, and Fig. 4 a longitudinal sectional elevation
illustrating another apparatus for pumping air or gases.
So far as the tank and building is concerned the apparatus is arranged same as
that above described, and as illustrated by Figs. 1 and 2. It is a double machine,
each formed by a central cylinder (a) with a smaller cylindrical projection a at
one end, in which a pivot a is carried, there being three pivots (a) for the double
machine, one in the middle having bearings carried by a beam d, having its ends
in the side walls, and supported by a pillar (5), and one at each end carried in
bearings secured on the end wall of the building. On each central cylinder (a)
there are two compartments (a³) formed on opposite sides of the cylinder a, each

page_text: compartment being open below for the water to enter, the water surface thus
forming one side of the compartment.
In cach compartment there is an inlet valve a³, which may be held so as not to
open by gravity by a spring or springs or weighted lever; and there is also an
outlet valve at in each compartment, which allows the gases from the compartments
to enter a passage (af) leading to the inner cylinder («), from which they pass to
the cylindrical projection a¹, which is perforated on its upper side with numerous
small holes, or it is covered with wire gauze to allow the gases to pass through and
ascend to the surface (e) of the water. Or the wire gauze may be stationary, and
the gases discharged under it from the cylinder a'.
The machine is oscillated to and fro directly by a piston and cylinder, and steam
or other motive power, or by a crank rotated by the power employed, which
crank is connected with a pin or short shaft, the ends of which are secured in those
ends or sides of the double machine which face each other, so that the compart-
ments () on one side are submerged, and then those on the other side alternately,
the water or liquid having but little motion imparted to it.
When the compartments descend the level of the water in the interior is
depressed, and the level of that on the exterior is slightly lifted until the pressure
is equal to that necessary to force the gases from the compartment, and cause theni
to pass into the central cylinders (a) and cylinders a¹, and through the water to the
chambers ³.
To avoid the descending and ascending movement of the water in the compart-
ments () a stationary piston may be arranged, as shown in peculiar dotted line on
the left-hand side of Fig. 3. This stationary piston a being supported on a pillar
or in any other convenient manner, the piston fits as close as possible to the inferior
sides of its compartment, just leaving clearance space, and the depth of the piston
is in excess of the head of water required to force the gases.
Cylinders or compartments by my Invention are or may be arranged to move up
and down vertically, being actuated by a steam cylinder and piston and rod con-
nected directly to the moving cylinder, which has a stationary piston, as above
described. The gases discharged from the cylinder would in this case pass through
valves in the stationary piston, and through its hollow support to be conveyed by
a pipe under wire gauze submerged below water or other liquid.
Before the products of combustion of the coal or other fuel are brought to be
operated upon by the apparatus referred to they are made to pass in contact with
that apparatus-for heating-feed water, known asram economizer," but extended-so
much as to reduce the heat of the passing gases as much as possible, the feed water
being pumped in at that end of the economizer where the gases have arrived furthest
from the furnace, so that the coldest gases will first act upon the coldest water, and
as the water progresses through the economizer and becomes hotter it will meet the
hotter gases.
The economizer is or may be divided into sections if desired, and the feed water
pumped from one section to the next hotter section. The heat, of the products of
combustion has not been reduced hitherto by the economizer below the temperature,
requisite to produce the draught by the chimney, and it is only by combining appa-
ratus for drawing or forcing the products of combustion with such additional econo-
mizer, according to my. Invention, that the reduction of the temperature of the
products of combustion is practicable.
Though I have described an illustrated apparatus for drawing and forcing air and
gases, I do not confine myself to such arrangements, as pumps of any other well-
known apparatus for drawing or forcing air or gases may be used which are capable
of producing sufficient pressure, and in such case the gases from the exhausting and
forcing apparatus are conveyed into an arrangement illustrated by Fig. 5, a sectional
elevation which is a closed cistern or tank filled with water up to the line c.
The gases pass in by the pipe or passage d!, descend a central pipe below the
surface (e) of the liquid, and pass under a frame a covered with wire gauze which
divides the gases as much as possible and causes them to ascend through the liquid

page_text: in such divided condition.
holes may be used.
Instead of gauze a thin plate or mеial periorated with
When the gases have ascended, to the space above the surface of the liquid they
pass out to the chimney at the pipe ³.
A fresh supply of water is or may be continually added to the cistern or tank (),
say at or near the bottom of the tank, and the surplus, carrying with it the floating
800t, overflows into a compartment f, from which it is drawn off at the bottom, but
not so fast as to leave the outlet orifice uncovered.
The outflow from this compartment f is or may be regulated by a valve and float
which will close or partly close the valve when the level is descending too low.
Fig. 6 is a longitudinal section, and illustrates another arrangement of apparatus
in which the gases are passed through water or other liquid for the purpose of being
purified.
This arrangement consists of a series of rectangular boxes which are made of
any desired and convenient size, and are or may be placed one upon the other
and side by side to any desired extent, according to the quantity of guses to be
treated.
When a series of such boxes or chambers (d) are used, each of the two ends are
jointed with a chamber which communicates with each box, and the gases to be
operated upon pass into the box or chambers d from the chamber at one end and
out from the chamber at the other end to the chimney. Each box d has one,
two, or more partitions & extending across it, and descending in an inclined position
from the upper side towards the lower side, and at the bottom of each partition
there is a frame (a) covered with wire gauze, which frame is or may be inserted
through a slit at one side of the box, which slit is closed by a cover when the frame
is inserted.
The boxes are filled to a certain level e with water or other liquid to be used,
and the gases enter the first compartment of each box and depress. the liquid
and pass under the partition (d), and are divided by the wire gauze (¹), and
ascend through the liquid to the second compartment, and from this to the next
compartment in like manner, and so on until they enter the outlet chamber (73.
A constant supply of fresh liquid is conveyed to each box d from a main pipe
and branches, the supply being regulated by a valve, and the surplus liquid overflows
into the chamber, from which it is drawn off as described in reference to the
compartment (f), Fig. 5, to pass to a settling tank.
In describing and illustrating the mode of carrying out my Invention I have
referred only to the method of drawing the gases into the machine and then
forcing them through the liquid, but my Invention may be carried into effect by
arranging so that the gases before they can enter the exhausting apparatus shall
pass through gauze or perforations, and through a depth of water or liquid before
entering the drawing or exhausting apparatus, and from this they may pass to the
chimney; or the gases may be drawn through the water to the exhausting
apparatus and forced by it through another depth of water or liquid before passing
to the chimney. ..
The apparatus which I prefer to use when drawing the air or gases through
liquid, or when both drawing the gases through liquid entering the machine and
forcing them through liquid when passing from the machine, is a double-action
piston, pump, or pumps, such as are employed for producing blast for furnaces in the
manufacture of iron.
In operating upon the products of combustion from furnaces not used for
generating steam, I prefer to cool the gases as much as possible and generate steam
from the heat thus obtained for giving wholly or partly the power required to work
the forcing apparatus employed where practicable.
In treating gases from fires in the dwelling houses of towns, the flues from the
houses of a district would have to be brought to one flue or sewer, but this would
only be practicable in building new towns, as it would be too costly to alter existing
arrangements.
...

page_text: For treating the noxious gases of sewage and manure works I prefer to pass the
gases through a furnace, say, the furnace or furnaces of the steam boiler, drawing
the gases in through the fire from the ash-pit by the apparatus which I employ for
-producing the draught and forcing the products of combustion through water or
other liquid. •
For treating the noxious gases, vapours, or discharges from chemical or other
manufactories, I use drawing or forcing, or both drawing and forcing apparatus, as
herein-before described, and force the gases through water, as described, or through
water mixed with other chemical ingredients, as may be best suited to the purpose,
which will vary in accordance with the character of the gases or vapours intended
to be treated, which' ingredients will be known to persons of ordinary skill in
chemistry.
L
But I wish it to be understood that I make no claim for any particular liquid (as
water is sufficient for purifying products of combustion), nor do I make any claim
for treating water or other liquid used in any process chemically, to cause it to
precipitate the matters with which it may be loaded.
↓
I employ the apparatus, herein-before described and illustrated by the Drawings,
for withdrawing the gas from the retorts of works for the manufacture of illuminating.
gas and for purifying the same, and it is also applicable for ventilating buildings
and mines, and cooling the air to be supplied thereto, by exhausting the air from
the building or mine and causing the entering air to pass through water or other
liquid, or by forcing the air into the building or mine by first forcing it through
water.
For further cooling mines and laying the fine coal dust in the atmosphere of
mines employ water under pressure dispersed in fine spray or steam in various
parts of the mine, so as to be carried along with the air passing through the
mine.
For freeing mines more effectually from gases I arrange so that the down-cast
shaft for the entering air may be closed, and employ pumps for drawing the air from
the mine, in which case the up-cast shaft is closed, except to a passage leading to
the pump or pumps which are worked, to reduce the pressure of the air in the mine
(say, when the men are not working) to the extent of, say, one pound per square
inch below the pressure when the men are working, and the pumps are kept
working to maintain this reduced pressure to within one or two hours of the men
commencing to work.
During the time the pressure is reduced the gases can freely escape.
Then a
sufficient time before the work commences air is allowed to enter the down-cast
shaft and the pumps continue working to exhaust the air from the mine, so that all
the gas which has escaped and accumulated during the low pressure will be
exhausted from the mine before the men begin to work.
The pumps are or may be used to assist the ordinary means of ventilation in the
daytime.
By another arrangement the pumps for reducing the pressure of the atmosphere
in the mine are or may be placed at the bottom of the shafts, pumping from the
up-cast air passage and discharging into the up-cast shaft, arrangements of air-
tight doors being provided to cut off the connection between up-cast shaft and air
passage and the down-cast shaft and air passage, so that air can only enter the
mine as allowed, and none can leave except through the pumps.
For deep mines, where the heat and pressure are excessive, pumps, arranged as
described, are or may be used during working hours, to reduce pressure and cool
the entering air by drawing it through water, but in this case two sets of air-tight
doors or valves would be required, placed some distance apart to form a chamber
between them, and one set of doors would have to be shut before the other were
opened for entering, and vice versa, when leaving the mine.
I have now particularly described the nature of my Invention, and the mode of
carrying the same into effect, and claim as my Invention,-
Firstly. The combination and arrangement of apparatus, substantially as herein.

page_text: before described, and illustrated by the Drawings, for drawing, and forcing air or
gases and cooling and purifying the same, whether used for treating products of
combustion or distillation or air for ventilating buildings or mines.
Secondly. The combination and arrangement of exhausting, or forcing apparatus
with additional economizers for drawing or forcing the products of combustion and
purifying them, substantially, as herein-before described, and illustrated by the
Drawings.
h
1
Thirdly. The treating of air or gases by drawing or forcing, the same through
numerous perforations, which cause the air or gases to pass through purifying or
cooling liquid in a divided state, substantially as herein-before described.
Fourthly. The laying of the fine coal dust in the atmosphere of coal mines by
the use of spray of water or steam discharged in the air passages in various parts
of the mine, or by passing the entering air through water, substantially as herein-
before described.
Fifthly. The system or mode of freeing mines from gases by reducing the pressure
of the atmosphere in them, substantially as herein-before described.
Sixthly. The system or mode of reducing the pressure in the atmosphere of deep
mines to cool the mine, substantially as herein-before described.
In witness whereof, I, the said John Smethurst, have hereunto set my hand
and seal, this Thirty-first day of December, in the year of our Lord One
thousand eight hundred and seventy-eight.
JOHN SMETHURST. (L.S.)