AN IMPROVED GAS APPARATUS
Year: 1815

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, SAMUEL
CLEGG, Engineer, of the Gas Works, Peter Street, Westminster, in the County
of Middlesex, send greeting.
WHEREAS His most Excellent Majesty King George the Third, by His
Letters Patent under the Great Seal of Great Britain, bearing date at West-
minster, the Ninth day of December, in the fifty-sixth year of His reign, did
give and grant unto me, the said Samuel Clegg, my exors, adñññors, and assigns,
His special licence, full power, sole privilege and authority, that I, the said
Samuel Clegg, my exors, admors, and assigns, during the term of years therein
expressed, should and lawfully might make, use, exercise, and vend, within
England, Wales, and the Town of Berwick-upon-Tweed, my Invention of
"AN IMPROVED GAS APPARATUS;" in which Letters Patent there is contained
a proviso obliging me, the said Samuel Clegg, under my hand and seal, to
cause a particular description of the nature of my said Invention, and in what
manner the same is to be performed, to be inrolled in His Majesty's High
Court of Chancery within six calendar months next and immediately after the
date of the said recited Letters Patent, as in and by the same, relation
being thereunto had, may more fully and at large appear.
NOW KNOW YE, that in compliance with the said proviso, I, the said
Samuel Clegg, do hereby declare that my said Invention of an Improved Gas
Apparatus is ascertained and described by these Presents and the Drawings
hereunto annexed, and herein referred to by way of illustration and example.
A

page_text: My Improved Gas Apparatus is for the purposes of extracting inflammable
gas by heat from pit coal, tar, or any other substance from which gas or gasses
capable of being employed for illumination can be extracted by heat; for puri-
fying the gas so obtained; and for measuring out and distributing it to lamps,
lights, or burners, where light or heat is to be produced by the combustion of
the said gas.
One part of my Invention is an horizontal flat retort, in which coal or
other materials capable of producing inflammable gas are heated and the gas
extracted by distillation. The fire by which this retort is to be heated is to
be applied so as to heat certain parts of its capacity much more than others,
so that some parts will thereby be heated to that degree which is proper for
the complete extracting of the gas, whilst other parts of the capacity of the retort
will be very slightly heated; and in some of those latter parts the door or opening
through which the materials are to be introduced into the retort is to be situated.
Within the retort a surface is to be provided, upon which the coal or other
substance to be distilled can be spread in a thin layer, in a horizontal position
or nearly so; and the said surface must be capable of a motion within the
retort for the purpose of removing the coals or other materials or other mate-
rials from the cooler part of the retort, at which they are introduced into the
same, to the hottest part of the retort, where the gas will be extracted by the
action of the fire. In this manner the coal will be heated slightly, and dried
previously to being subjected to the red or greatest heat, and, from being
spread thin, will require a less proportion of fuel to heat it, and the gas will
be obtained in less time than by means of the retorts now commonly used to
gas apparatus. Also, the coke which remains upon the moveable surface, after
the
gas
shall have been extracted from the materials, may be removed from
the hottest part of the retort to the cooler part near the entry door, at which
it is to be withdrawn and replaced with fresh materials. Retorts upon this
principle may be constructed of various forms, either circular or otherwise, with
the bottom horizontal or nearly so, and the motion of the surface upon which the
materials are spread may be circular, upon a centre, or otherwise. The manner
of constructing a retort of a circular figure is explained by the Drawings here-
unto annexed, Fig. 1, 2, 3, 4, and 5, and the references thereto. But be it
observed that, altho' such a construction will effect all the purposes which I
have stated, the form, proportions, and arrangements of its parts may be
greatly varied and modified, according as circumstances or situation may
require.
Another part of my Invention is an improvement in the purifying apparatus
to be placed in the vessels into which the gas from the retort is conveyed for

page_text: the purpose of being purified by exposing it to the action of lime and water.
The common purifying apparatus consists of a large vessel closed on all sides
to receive the gas after it has been purified; within this is a smaller vessel or
lime trough open at top to contain lime and water; and there is also a third
vessel or inverted trough into which the gas is received immediately from the
retort. This inverted trough is open at bottom, and the edge of the open part is
immersed beneath the surface of the lime and water which is contained in
the lime trough, so that the gas which is introduced into the last-mentioned
inverted trough cannot escape therefrom except by rising up through the lime
and water; to facilitate this, holes or openings are made through the sides of
the inverted trough near the bottom edge thereof, which holes or openings are
beneath the surface of the lime and water contained in the lime trough, so
that the bubbles of gas are obliged to rise up through the same and thereby
become purified. This is the nature of the common purifying vessels in
which the said holes or openings become frequently stopped by the lime unless
water is mixed with it in sufficient quantity to render the lime completely
fluid. My improved purifying apparatus, in addition to the above-mentioned
parts, has
shaft or axis furnished with teeth or projecting claws, and so
applied within the interior inverted gas vessel that it can be put in motion
from the outside of the apparatus, and that its teeth, when in motion, will
pass through and scrape out the said openings every time the axis is moved
round. I also make the lime trough moveable on a centre or axis, in such
manner as to be able to invert or incline it by a motion from the outside for
the purpose of discharging the lime which it contains into the bottom of the
external vessel from which it can be drawn out at pleasure. With this purifying
machine I am enabled to employ lime water of semo-fluid consistence, like
thick cream, in which state it is contained in so much less bulk that, after it
has become impregnated with the foetid impurities which it absorbs from the
gas, it can be carried off from a manufactory without the difficulties which
occur in getting rid of the disagreeable lime water when it is quite fluid, as
in the common apparatus.
A purifying apparatus fitted up according to my Invention, and in which
the teeth or claws which clear out the openings have a rotary motion, is shewn
in Figures 6, 7, 8, and 9, and explained by the references thereto; but the
same effects may be produced by giving a rectilinear motion to the teeth or
claws, as it only requires the openings to be of a different form or shape.
Another part of my Invention is, a guage or rotative gas-meter, for mea-
suring out and registering the quantity of gas which passes through a pipe or
opening so as to ascertain the quantity consumed by any certain number of
13

page_text: lights or burners. This guage consists of a hollow wheel or drum capable
of revolving vertically upon pivots in the manner of a water wheel. The
hollow rim of the wheel is made close on all sides to form a circular
channel, which is divided by partitions into certain compartments or
chambers to contain the gas which is introduced into the wheel through one
end of its axis, and carried off from the wheel through the other end. By
certain contrivances it is so arranged that each of these boxes or chambers
will be filled with gas from the entrance pipe and emptied of the same into
the exit pipe every time the wheel makes a revolution, by which means the
number of turns the wheel makes when registered by suitable wheelwork,
become a record of the quantity or number of boxes full of gas which has
passed through the guage. The gas is conducted from the place whence it is
supplied, and enters into the guage through one end of its axis, and is con-
veyed into the chambers of the rim by certain hollow arms. The gas returns
from the said chambers by certain other hollow arms, and is conveyed away
through the opposite end of the axis of the wheel by the pipe which leads to
the burners or place where the gas is consumed. No gas can pass from the
pipe of entrance at one end of the axis and get to the pipe of exit at the
other end of the axis without entering into and filling the said chambers. A
sufficient quantity of water is put into the hollow rim of the wheel to fill a
segment of the rim rather larger in its capacity than one of the compartments
into which it is divided, and there are passages of communication between the
chambers through which this water can pass from one chamber into the next,
but the gas cannot pass. It is evident that the water, from its gravity, will
always fill a segment in the lowest part of the wheel, and when the same turns
round the water will occupy each of the chambers in succession as they
arrive at and during the time each one continues at the lowest part of the
wheel. The pipes or hollow arms which convey the gas to the chambers are
so contrived, that when the entrance pipe to any one chamber is open to
admit the gas, the exit pipe from the same chamber will be shut or sealed up,
and vice versa, and this opening and shutting of the passages into and out of
any one chamber takes place at that period of the revolution of the wheel
when the water in the lower part thereof is on the point of entering into or
going out from the said chambers, that is to say, when the water at the lower
part of the wheel is on the point of quitting any chamber, the pipe of entry
shall be open to admit gas into the said chambers, which gas expels the water
from it through the passage of communication into the adjacent chamber until
the first-mentioned chamber becoms filled with gas, and the second-men-
tioned chamber becomes filled with water; at the same time the pipe of exit

page_text: from the second-mentioned chamber is opened, and the water which enters
from the first-mentioned chamber displaces the gas, and it passes off through
the exit pipe. The machinery for counting and registering the number of
revolutions made by the wheel may be constructed in any of the ways usually
employed for similar purposes. It is not essential to this guage that the exit
pipe from the chambers be conveyed through the axis, the same effects may
be obtained by enclosing the whole wheel within a close vessel or case in which
it can revolve freely, and allowing the gas to escape into the case from the
chambers; when the same are to be discharged from this case, the gas can
be carried off by the exit pipe. The means of opening or shutting the pas-
sages of communication may be varied; it may be done either by valves or by
sealing the pipes with water or other fluid. A gas meter is represented in
Figure 10, and explained in the reference thereto; also in Figures 11, 12, &
13 another kind is represented, but the construction admits of great variation,
provided the properties above enumerated are preserved.
Another part of my Invention is, a self-acting governor for regulating the
efflux or discharge of gas through any opening or openings or burners at which
the gas is to be burned, so that the gas shall always issue from the said
openings or burners with an uniform velocity, or nearly so, notwithstanding any
variations which may take place in the pressure which urges the gas to pass
through the pipes of supply. The pipe through which the gas passes to the
burners must have in some part of it an apperture which is capable of being
increased or diminished in its opening by a very slight force; and motion for
diminishing or encreasing the apperture is given by a small gasometer or
inverted vessel, the mouth of which is immersed under water, and its interior
capacity communicates with the pipe of supply beyond the part where the
apperture for regulation is placed. The gasometer must be sufficiently loa led
to retain the gas within it at such a degree of compressure as will cause the
gas to issue from the openings or burners with that degree of velocity which is
necessary to support a required height of flame. Now if the pressure of the
gas in the pipe of supply is encreased, it causes the gasometer to rise up more
out of the water, and this motion is made to diminish the opening through
which the gas passes in such proportion that the velocity with which it will
flow or issue from the openings or burners, and consequently the height of the
flame, will continue the same or nearly so; or, on the other hand, if the
pressure of the gas in the pipe of supply is diminished, the gasometer will sink
lower down into the water, and this motion is made to enlarge the opening a
proportionate quantity to effect the intended regulation. The gasometer or
inverted vessel for this purpose may be made of a prismatic form, to rise and

page_text: fall vertically in the water, or it may be made to rise and fall with a circular
motion upon a centre; in either case it should give motion to a lever, and this
lever should effect the regulation of the opening by a communication from
a part nearer to the centre of its motion, in order to render the motion for the
regulation very small. To make the apperture through which the gas is to
pass capable of delicate adjustment, I make the said apperture in a vertical
plane, or approaching thereto, in order that the lower side margin or boundary
of such apperture may be formed by the horizontal surface of mercury, tar,
water, or other fluid, which is contained in a cup or bason suspended from the
lever of the gasometer near the center thereof, in this way when the ascent
of the gasometer causes the cup to rise up the surface of the fluid rises with
it and diminishes the height of the apperture through which the gas passes,
so as to contract the area thereof; and on the contrary, by lowering down the
cup, the apperture for the passage of the gas will be increased. One of the
forms, among many others, in which this governor may be constructed, is
represented in Figure 14 of the Drawings, and explained in the reference
thereto.
Having now ascertained my Invention of an improved gas apparatus, and
defined in what it consists, I shall proceed to describe the same, and to shew
by the assistance of the Drawings in what manner it is to be performed, first
observing that the said Drawings represent the apparatus in its most complete
state, but that the arrangements of the parts, and the construction of many of
the minor parts, may be varied and modified according to the situation
in which the apparatus is placed, and the circumstances governing the
same, without at all deviating from my Invention as I have defined the
same.
REFERENCES TO THE DRAWINGS HEREUNTO ANNEXED.
Figures 1, 2, 3, 4, and 5 represent my horizontal flat retort of about 12
feet in diameter; it is made from plates of iron or other proper metal riveted
together in the manner of boilers, and in the form represented in the section
Fig. 2; it is supported in brickwork, as represented in Fig. 5, so as to be over
the fire-place C or furnace, by which it is heated, and the opening through
which the materials are to be introduced and withdrawn is at E, Fig, 2. B is
a perpendicular shaft or axis placed in the center of the retort; and to the
lower end of this several iron arms a, a, are affixed, radiating from the centre,
as shewn in Fig. 3, and extending near to the circumference of the retort.

page_text: or groove being made formed in the lower or under side of each box, as shewn
by Fig. 3, which notch is deep enough to receive the arm a upon which the
box is suspended. Each box is formed to the segment of a circle, so that the
whole number of boxes being suspended on the arms, as represented in Fig. 1,
form a circular tray or dish, which covers the whole of the bottom of the retort,
or nearly so, and is capable of being turned round within the retort by the
levers d, d, upon the upper end of its axis B. By this motion of the boxes
upon their axis any one can be brought opposite to the door E, to be with-
drawn from the arm to which it belongs; and each box is provided with a
latch, fixed upon the outside or end thereof, and falling into a notch in the end
of the arm a, to hold the box upon the arm when in its place, as in Fig. 1;
but this latch being lifted up, the box can be slided off from the arm through
the door E, which is large enough to admit it to pass freely. C, No. 5,
is the fireplace, and 1, 2, and 3, the flues which conduct the flame beneath
the retort, as shewn in Fig. 4; but these flues are only carried under about
one third of the area of the bottom of the retort, and, after rising up at 4, the
flue is carried over the same part of the retort at 5, and then passes into the
chimney. By this means about one third part of the whole retort is heated to
the temperature required for extracting the gas, and if there are 15 boxes
placed upon the arms of the axis B, only 5 of the number will be exposed to
the full action of this heat at the same time. The mouth of the retort E at
which the boxes are separately introduced or exchanged is on the opposite side
to that which is heated by the fire, and this opening is provided with a door or
lid 6, Fig. 5, which is ground to fit tight against the edge of the opening, and
has a bar or frame 15 fastened to it, and jointed at the upper and lower end to
two rods 7, 8, which move on centers at 9, 9, and there are spiral springs, or
some other kind of springs, at 10, to draw the door close; but at the same time
the motion of the rods 7 on the centers 9, as shewn by the dotted lines, allow
the door 6 to be slided down below the opening into the retort, to permit the
boxes to be introduced or withdrawn from the retort by sliding them off the
arms a of the axis B. The frame 15, by which the door 6 is connected with
the rod 9, is also shewn in a front view at ✗, to explain the opening through
it at which the boxes are introduced when the door is slided down. The
weight of the door 6 and of the upright frame 15 must be counterbalanced by
a weight or spring applied at the upper end of the rod 11. The axis B, by
which the boxes are turned round, passes through an opening at the top of the
central tube which rises from the top of the retort, and the opening is made
air-tight by means of a circular invented cup, which is fixed to the axis, and
its lower edge is immersed beneath the surface of oil, fluid metal, on any other

page_text: fluid or substance capable of resisting the pressure of the gass; and, notwith-
standing the heat, the said fluid is contained in a circular cup or channel
formed around the opening in which the axis moves. The uppert part of the
axis B is suspended in a collar and by two rods 12, and by a screw 13, or by
other similar means. The axis, and all the boxes suspended from its arms,
can be raised up from the bottom of the retort, or can be lowered down to rest
flat thereupon. The lower end of the axis is perforated with a hole to receive a
cylindrical pin which rises perpendicularly from the bottom of the retort, by
which means the axis may be raised up, but always preserves its center.
Levers d, d, or any kind of wheelwork, are fixed upon the upper end of the
axis to turn it round by, and cause all the boxes to revolve in the retort, when
they are raised up a little from the bottom of the retort by means of the screw
or other power. To ascertain the position of the axis which will bring cach
box exactly opposite to the door of the retort into a fit position for drawing
out the box, pins or teeth are fixed into the edge of a wheel at the upper end
of the axis B, corresponding with the several arms upon which the boxes are
suspended, and these pins being brought oposite to any fixed pin or mark
will determine the proper portions. And for the facility of sliding in and out
the boxes, an iron table 14, Fig. 5, is placed on a level with the bottom of the
retort. Upon this table an iron bar is fixed up edgeways to correspond with
the arms, and the box, being placed upon the bar and slid forwards, will be
conducted into its place upon the arm; the same of withdrawing a box.
The iron table is made of sufficient length to hold several boxes ready filled
and in a state to be introduced into the retort. D is a pipe by which the gas
is discharged from the retort, and carried of to its distination. It is situated
over the coolest part of the retort, in order that the coarser part of the coal tar
may condense and fall down upon the coal contained in the boxes, and be
subjected with them to the action of the heat when the axis is turned round to
carry those boxes into the heated part. The operation of this retort will be as
follows-The coal must be thinly spread in the boxes in layers from 1 to 3
inches in thickness, and the door E being slided down, the boxes, one by one,
are placed on the iron bar which is across the table 14, from which they are
introduced through the door E, and slided into their place upon the arms of
the axis. The whole circle being filled with boxes in this manner, the axis is
lowered down to let the boxes rest upon the bottom of the retort, and one third
of the number of boxes, or the five which are immediately over the fire, are
exposed to the heat a sufficient time to expel the gas from the coal, at the
same time the coal in the other boxes is gently heating and drying. The
whole circle of boxes is moved round one third of the circle by suspending it

page_text: with the screw 13, and turning the axis; this removes the 5 boxes from the
action of the fire towards the door, and brings 5 other succeeding boxes over
the fire to undergo the same operation. By this succession, when the first-
mentioned 5 boxes which contains the coke or coal from which the gas has
been extracted arrive at the door E they must be drawn out and replaced with
others containing fresh coal; therefore, so long as this operation is continued,
one third of the number of boxes, viz', those last introduced, are drying and
warming previous to their undergoing the red heat; another third are over
the fire; and the remaining third, which have been heated, are cooling ready
to be drawn out. The gas which is produced in the retort is next conveyed to
the purifying apparatus.
Figures 6, 7, 8, and 9, represent my improved purifying apparatus. A, A,
B, B, is the large vessel, which may be made of cast-iron plates screwed
together, or of any other fit material. The lower part of it B, B, is formed
like a hopper, so that the simi-fluid lime will drain down to the lower part t
be drawn off through a sluice cock D. The gas which is to be purifyed is
brought to the apparatus by the pipe E, Fig. 6, and conveyed away from it in
a purified state by a pipe at F, or at any other convenient part of the vessel.
The pipe E passes down through the top of the great vessel, and is conducted
into the top of the inverted box G, G, so as to convey all the gas into the
said inverted box; and the opening or lower part thereof being immersed
beneath the surface of the lime water which is contained in the lime trough
HI, the gas cannot escape from the inverted box G without passing through
the openings or upright slits which are made through the sides of the box
near its lower edge and bubbling up through the lime water. An axis or
spindle I extends horizontally the whole length of the inverted box, and upon
this are fixed as many projecting teeth or claws 3 as there are openings through
each side of the inverted box.
Figure 9 is a transverse section of the inverted box and lime trough on a
double scale, to shew the form of the openings through the sides of the box
and the manner in which the projecting teeth 3 of the axis I pass through
them when the axis revolves. The teeth operate first on the openings in one
side of the box and then in those at the other side; the sweep of these teeth,
as represented by the dotted circle, is such, that the teeth will pass quite
through the openings and keep them clear. Those parts of the teeth which
enter into the openings are narrow, in the direction of their motion, but that
part of each tooth which is nearer to the center is made broad and flat, as
shewn seperately at X, by which means the teeth will act as rowers to agitate
and keep the lime water in constant motion when. they revolve. But be it

page_text: observed, that I do not claim the invention of agitating the lime water by
this means, but only the property of clearing out the openings, as before
ascertained. The inverted box G is supported within the great vessel by
cross bars K, and the axis I is put in motion by a handle on the outside, as
shewn at L, Fig. 6, the spindle of which passes through the side of the vessel
with a stuffing box, and has wheelwork M withinside to communicate the
motion to the axis I. The line which is to supply this apparatus is put into a
vessel T placed on the top of the vessel A, and a sufficiency of water being
mixed with it, it is stirred up to the consistence of cream by the arms upon
the lower end of the perpendicular axle N; when the lime is thus prepared,
a sluice cock P is opened to draw it off by the curved pipe O, O, which turns
down through the top of the great vessel A, and also through the top of the
inverted vessel G, so as to introduce the semi-fluid lime into the same, and it
falls down into the lime trough H. For discharging this lime from the lime.
trough when it has become charged with the impurities which it has absorbed
from the gas, the whole lime trough is inverted or inclined into the position of
the dotted lines Figure 8. To effect this, the lime trough is supported in the
vessel A by an axle or spindle R to which it is affixed, and the end of the
axle comes through the end of the vessel, where it has a lever S, V, fixed
upon it to give motion to the trough; also a counter weight V to balance the
weight of the trough. By this means the simi-fluid lime when done with is
discharged into the lower part of the large vessel A, B, from which it can be
drawn off through a sluice or cock W, when the same is to be conveyed away
from the manufactory. The lower orifice of the pipe which descends from
the cock W is immersed in a cup or bason Y, to prevent the gas escaping
from the orifice. When the lime is suffered to run out, this cup or bason is
supported upon a lever Z, which permits the vessel to be removed and cleared
out when the cock is shut. The gas, after being purified by the action of the
lime in the purifying machine, is conveyed to a gassometer, in which it is
received and retained till wanted. This gassometer, being the same as in
general use, and forming no part of my Invention, need not be described
here.
Figure 10 is a section of a gas meter constructed in its simplest form, for
measuring the quantities of gas which passes through it, and may be placed in
any part of the apparatus where it is desirable to ascertain the quantity of gas
which passes.
A, A, is a box of any convenient figure or dimension, close on
all sides; it may be circular, as represented by the thick black outline, or
octagonal, as shewn by the dotted lines, but it must be sufficiently large to
contain a wheel or drum B, B, C, C, and allow it to revolve freely upon its

page_text: centre. The wheel consists of an outer rim B, B, of thin metal plate, and
inner rim C, C, of the same material, and the two being connected by side
plates, which are shewn by the shaded part, form a hollow rim to the wheel.
This hollow rim is divided into two parts by divisions D and E, so as to make
two separate chambers, which for distinction are marked in the Drawing First
Chamber and Second Chamber. There is a communication in one direction
between these two chambers by valves 2 and 3, which open respectively
towards the figures 2 and 3, but are kept closed in a contrary discretion by
the action of slender springs at 4 and 5; openings or slits are made through
the side plates of the rim to allow the gas to pass from the chambers into the
box or external case A, from which it can be conveyed by the pipe F to its
distination. The gas which is to be measured by this guage is introduced
into the wheel at one end of the axis G, which is made hollow for that purpose,
and the junction of the revolving axis with the pipe of supply is made tight
by a box represented in Figure 11, and described in the thereto. The
gas is conducted from the axis into the chambers through the crooked arms
Hand I which are hollow for that purpose, whilst the other two arms K, K,
are solid, and are only to sustain the rim of the wheel. A quantity of water
is put into the case A, A; and, as there is a free communication between the
chambers and the external case A, when the openings 4 or 5 are beneath
the water it will stand at the same level, 7, 8, in the inside of the hollow rim,
as in the bottom of the external case. The gauge is made to measure the
quantity of gas which has passed through it, by the arrangement of the
passages H and I, which are for the entry of the gas from the axis G into
the chambers, and of the holes 4 and 5 for the exit of the gas from the
chambers into the external case. This arrangement is such, that the gas
which is just introduced into either chamber shall not be able to escape from
the same until it has quite filled the chamber; the passage of entry is then
shut to prevent any more gas from entering, and the passage of exit is open
to allow the chamber to discharge its contents of gas. The same arrange-
ment also insures that the pipe of entry shall not be again opened to admit
any more fresh gas into any particular chamber until the gas before intro-
duced shall have quitted the same, or, at least, that it shall prevent the
mixing of the gas formerly introduced with that which will be introduced
when the pipe of entry is again opened. This alternate filling and discharging
the contents of each chamber is made to take place once to every revolution
of the wheel, and thereby the number of revolutions which the wheel makes
shews the number of times each particular chamber has been filled with and
emptied of gas. The crooked pipes of entry II and I are shut to prevent the

page_text: further admission of gas by pouring water into the bends thereof. This
water is raised up in small buckets, L, M, which are fixed to the inside
rim C, C, of the wheel. These buckets, when in the situation of M, are filled
with water, which they carry up to the top of the wheel as at L, and suddenly
pour it over and it runs against the partition D, and down into the crooked
pipe H, in the bends of which it remains and stops the passage of gas from
the axis G until, by the revolution of the wheel, the whole of the water drains
out of the bends and reopens the passage for the gas at I. The openings 4
and 5 are situated at the ends of their respective chambers, so as to be as far
as possible from the orifices of the pipes H and I, which introduce the gas
into the said chambers, by this means the openings will not immerge from the
surface of the water at 8, so as to allow the exit of the gas until the pipe of
entry into the same chamber is stopped up; and to insure that this shall be the
case, hoods or covers are soldered on the outside of the rim of the wheel over
the openings 4 and 5, and these hoods turn down as far as the dotted lines 13,
therefore the gas cannot issue through the openings 4 and 5 until the orifices
of the said hoods at the dotted lines 13 arive at the surface 8. These parti-
culars being understood, the action of the gauge is as follows:-Suppose the
external case and the wheel, with water in the bottom and the other parts full
of gas, as represented in the Figure, the gas which enters by the axis G
passes through the arm 1 into the second chamber, and acting, by its expan
sive force (or rather, in consequence of the pressure which urges it forwards)
between the surface of the water at 8, and the partition at E, it will turn
the wheel gradually round in the direction of the arrow as fast as the gas
enters into the second chamber. The gas contained in the other end of the
second chamber, namely, that which is between the surface of the water at 7
and the partition D, has no communication with the gass newly introduced
through the crooked arm I into the opposite end of the same chamber
between 8 and the partition E, because the water 7, 8, contained in lower
part makes a complete separation between the two parts of the second
chamber. The motion of the wheel, which is thus occasioned by the intro-
duction of the fresh gas into the second chamber at 8, causes the gas which is
contained in the same chamber between 7 and D to pass through the open-
ing 5 into the external case, from whence it is carried off by the pipe F to
the place where it is wanted; and when this quantity of gas is completely gone,
or in other words, when the partition D arrives at the surface of the water 7,
the valve 2 opens by the action of the water, although it would not open to the
gas, and allows the water to enter into the first chamber from which it will
expel an equal quantity of gas, which will then have risen above the surface 8,

page_text: into the external case through the opening 4; when the wheel has thus made
half a revolution, the second chamber will be full of gas, and it will stand
exactly in the same position as the first chamber does in the Figure; I shall
therefore proceed to describe the action of the first chamber, which may at
the same time be considered as a continuation of the description of the action
of the second chamber. The Figure represents the first chamber in the
position at which it is full of gas newly introduced by the crooked pipe H;
and this gas has had no means of escaping into the external case, because the
opening of the exit 4 was covered with water. The bucket L is just arriving
at the top of the wheel, and in a moment will discharge its contents down the
crooked pipe H and stop up the passage thereof, to prevent any further
entrance of gas into the first chamber. Immediately after that has taken
place, the opening 4 will rise above the surface of the water and allow the
exit of the gas from the first chamber; but this gas, although at liberty, will
not pass out untill the partition D arrives at the surface of the water, which
will then open the valve 2 and begin to occupy the first chamber, from which
it will displace an equal quantity of gas through the opening 4 into the
external case. When the orifice of the crooked arm H descends to the water 7,
the water which stopped it up will begin to run out, but still the gas cannot
flow through this same pipe untill its mouth arrives above the water in the
position I, when the operation before described takes place, and so on con-
tinually, that is to say, the gas entering into the wheel above the surface of
the water at 8, presses against the adjacent partition E, and turns the wheel
round, and in consequence of this motion the other partition D presses the
gas down upon the surface of the water at 7, and causes it to pass through
the opening 4 in a equal quantity to that which is introduced at 8.
Figures 11, 12, and 13, represent a gas meter of a construction rather
different from the former, and more particularly adapted for measuring large
quantities of gas. For the ease of description such parts as are common to both
are distinguished by the same letters of reference as in the former Figure.
B, B, is the hollow rim of the wheel, which is divided into three chambers by
partitions D, E, O. The gas is introduced at one end of the hollow axis G,
and conveyed into the chambers of the crooked arms H, I, N, which are
sealed by water carried up in the buckets L, M, & 20, in the same manner
as the former gas meter, Figure 10. The principal differences in the
present gas meter are, that it has three chambers instead of two, and that the
gas, instead of being conveyed into an external case, is carried off from the
chamber through the opposite end of the axis at F, Figure 11. Also the
passages of communication between the different chambers, which in the other

page_text: gas meter, Figure 10, is through the valves, is in this effected by the
scrolls 2, 3, 9, and 10, 11, 12. These scrolls are nothing more than a pipe
carried from one chamber into the middle of the next, where the pipe is
curled or scrolled as in the Figure, but the end is left open. Through these
scrolls the water will have free passage from one chamber to another, when
the scrolls are in the position of 3, but when they rise up above the water
into the position 2, 11, and 9, a sufficient quantity of water will always remain
in the passages of the scrolls, so as to seal the same and prevent the passage
of gas. The axis F, G, of the wheel rests upon friction wheels 18, as shewn
in Figure 11, so as to turn round with all the freedom possible. These fric-
tion wheels are supported by frames erected from the sides of a cistern A, A,
which contains water to take off part of the weight of the wheel, but this water
has no communication with the interior of the wheel. The pipe of supply
which brings the gas to the wheel is soldered or screwed with a flaunch to
a circular hollow box 14, which is bored out at each end to fit the
end G of the hollow axis, while the middle part of the interior of the
box is larger, so as to leave a space all round the axis G, as is repre-
sented by the shaded part. This space is filled with tar or other semi-fluid,
which will prevent the escape of the gas between the end of the axis G and
the pipe of supply, but at the same time will admit the axis to turn round
freely within the box. A similar box is applied at the opposite end F of the
axis to connect it with the pipe which conveys the gas away. (Note.-The
former gass meter, Figure 10, has one of these boxes 14 soldered into the
external case, and the axis of the wheel is made to revolve therein, so as to
introduce the gas into the wheel without allowing it to escape into the case.)
The gas is carried off from the chambers through the hollow arms 4, 5, and
13, to the end of the axis, which has no communication with the end G,
but the said pipes or hollow arms do not communicate with the chambers to
which they are immediately directed; but the arms, after being carried within-
side the chambers are carried round as represented, so as to communicate with
the next preceding chamber; thus, the arm 4 is for the purpose of carrying off
the gas from the first chamber, the arm 5 for the second chamber, and the
arm 13 for the third chamber. Those passages which are for the entrance of
the gas into the chambers, as well as those parts which are necessary to cause
the action of those passages, are represented of a copper colour, and those
passages and parts which are for effecting the exit of the gas are colored
yellow; with attention to this distinction the following explanation of the
action of the gas meter will be intelligible-In the situation of Figure 12
gas is entering into the first chamber from the axis G through the pipe H,
the

page_text: which is open. The pipe of exit 4 from the same chamber is shut, because
it is beneath the water, which, however, has free communication from the first
chamber into the second through the scroll 3. In consequence of this gas
expanding itself between the surface of the water at 8 and the partition D, it
turns the wheel round in the direction of the arrow. This motion causes the
partition O to approach the surface of the water at 7 and the gas of the
second chamber, contained in the space between the two surfaces 7 and O,
passes through the passage 5 to the end F of the axis in an equal quantity to
When the partitions E
will be full of gas, and
that of the gas introduced into first chamber at H.
rises to the surface of the water at 8 the first chamber
then the bucket L will discharge its water into the pipe H so as to close that
passage, and prevent the further entrance of gass into the first chamber; at
the same time the end of the pipe I will arrive about the water at 8 and
introduce fresh gas into the second chamber; also the partition O descending
beneath the surface 7, the water will begin to pass the scroll 12 into the third
chamber, and begin to displace the gas therefrom through the passage 13 as
fast as fresh gas is introduced through I into the second chamber. In this
way the action of the gas meter or wheel is constantly kept up; but there
are some other particulars which it is necessary to mention. As soon as the pipe
of entry H is sealed, the exit pipe 4 will emerge from the water at 8 and be
opened, but the gas will have no tendency to quit the first chamber until the
partition D descends beneath the water at 7. The curved part of the
passages 4, 5, and 13, when the same rise up above the surface 8, will be full
of water, because their orifices into their respective chambers are uppermost.
To get rid of this water, and allow it to drain out into the rim of the wheel
without getting through the arms into the axis, a small pipe 15 is soldered to
the end of each passage, and these small pipes are looped or bent like the
letter S, in order that a small quantity of water may always remain in the
loops and prevent the escape of the gas through the same passage when they
rise above the surface 8. Also to drain off any small quantity of water which
may lodge in the interior loops of the pipes of entry,-as, for example, in the
loop 21 of the exit pipe J.-I conduct a small tube or pipe from the said loop
to the inside of the rim of the wheel in the direction shewn by the dotted
lines 22; and to prevent the escape of any gas through the same pipe when
its orifice is above water, the end thereof which is contained within the
rim of the wheel is curled into a scroll, as shewn by the dotted lines,
by which means a sufficiency of water will always be left in the curve
scrools to stop the passage of gas, although the passage for water will
be uninterrupted. A similar pipe may be applied to each arm at 22, and

page_text: also to the arms of the former gas meter, Fig. 10, if found requisite. It
now only remains to explain the use of certain smaller scrolls, two of which
are affixed to each copper-colored scroll, as shewn at 16, and two similar ones
17 are applied to each yellow scroll; but as the latter are not represented in
section, they have a different appearance. These small scrolls are provided to
allow the gas which the large scrolls contain to escape from the upper parts of
the curls thereof when the same are beneath the water as at 3, and facilitate
the passage of the water through them, which would otherwise be impeded by
that small quantity of gas which must occupy the interior of the scroll, and
which, being confined by the water entering at each end of the scroll, would
be in the same situation as if beneath an inverted cup. The small scrolls 16,
which are attached to the great scroll 3, shew a small white dot 26, which is
the orifice of a duct leading from the interior of the great scroll to the dark
spiral passing of the small one; and 27 is a small hole passing out sideways
from the said interior passage, and opens into the chamber of the wheel; the
passage of the small scroll leads from one of these holes to the other by a
spiral rout, and a small quantity of mercury is put into the passage, as shewn
at 25. Now when the great scroll is under water, as at 3, the mercury 25 is
in such a position that it allows the gas which is contained in the scroll 3 to
pass freely through the duct 26, and thence by the spiral passage of the small
scroll to the hole 27, at which it escapes in bubbles; but after the scrolls
have risen out of the water, as at 2, it is necessary to prevent the water
leaking out of the same holes through which the gas escaped. This is effected
by the mercury 25, which descends in the passage as soon as the scroll rises
above the water, and stops the communication between the two holes 26 and
27. By observing the position of this mercury in all the different parts of the
motion of the wheel, it will be found that it will never allow the water to run
from the scrolls when they are above water, although it will always allow the gas
to escape from the great scrolls when they are beneath the water. These small
scrolls may be either made of glass or of iron, or of any material which will not
be acted upon by mercury. The separate Figure 13 represents one on a large
scale made of iron; it is cast in two halves, with the curved passages as there
represented made in each half, so that they will make a complete spiral tube
when fitted and riveted together by the pins c, c, c. When so put together,
the end is cemented into a brass tube d, which is screwed into a socket sol-
dered to the outside of the great scroll. It is between the outside of the iron
and the inside of the brass bube d that the duct or communication is carried
from the hole 26 to the interior of the great scroll to which the small scroll is
attached. The passage of the scroll is continued beyond the hole 27 a suffi-

page_text: cient distance to contain the necessary quantity of mercury at that part when
the passage from 26 to 27 is to be left uninterrupted; also the passage at the
part where the hole 27 is made is so much enlarged that the mercury can run
by the hole without escaping through the same. The wheelwork which is
applied to the gas meter may consist of a single pin or tooth fixed in the axis,
or in any other convenient part, so that at every revolution of the wheel it
shall operate in the teeth of a count wheel and move the same one tooth.
This wheel may actuate a train of wheelwork, with hands and dials, to shew
the number of revolutions the wheel has made, or the quantity of gas which
has passed through it.
the
Figure 14 is a section of the governor. A is the pipe of supply which
brings the gas, and B the pipe which conveys the gas away to the burners.
The pipe A turns down and communicates with a short piece of a large pipe
C, D, in which is a partition E. The lower end of the pipe C, D, is open,
and is immersed beneath the surface of mercury or other fluid which is
contained in a cup F. An opening or passage is made in the partition E for
gas to flow through from the pipe A into the pipe B'; but as the lower
part of this opening E is formed by the surface of the fluid in the cup F, it
is plain that by raising or lowering the cup the fluid will rise or fall, and
increase or diminish the size of the passage E for the gas. A branch R turns
up from the pipe B, beneath the small gasometer G, G, which rises and falls
in the cistern H, HI, containing water. The gasometer is guided in its motion
by a perpendicular stem or wire I in the centre, which is received in a tube
passing through the centre of the gasometer G, and soldered tight thereto.
K, L, M, is a lever moveable in the fulcrum or centre L, at the upper end of
a pillar. At the end K of the lever is an arch for a small chain, which is
attached to the gasometer, and N is a small arch nearer to the centre for
suspending the cup F, which contains the fluid; also at the opposite end of M
of the beam a weight is applied to counterbalance the weight of the cup. The
operation of the governor is to regulate the pressure with which the gas shall
be urged to issue at B; this pressure is determined by means of a certain load
applied upon the gasometer G, so as to occasion a sufficient difference between
the level of the water withinside the gasometer G and the level of the water
on the outside thereof in the cistern H. The action of this governor will be
to keep this pressure constantly the same; for if the pressure of the gas at A
is increased so as to force a greater quantity through the opening E, the
pressure within the gasometer will be also encreased, and cause the gasometer
to rise up; this motion elevates the cup F, and contracts the opening of the
passage E to such a degree as to diminish the quantity which shall pass through
R

page_text: the said opening, until the pressure within the gasometer is restored to its
original degree; in the same manner, if the pressure at A is diminished, the
quantity of gas which will pass through the opening E will also be diminished,
so as to allow the gasometer to descend lower into the water, and then by
lowering the cup F to allow a greater quantity of gas to pass, and restore the
intended pressure in the gasomer. The governor will effect the regulation
in an equal degree when the inequalities of pressure are occasioned by an
increased consumption at B, as when they are occasioned by an increased'
pressure at A, for the operation of it is to adopt the opening E to the quantity
of gas which is required to pass, so as to keep the pressure under which the
gas shall issue nearly equal. The burners, or parts where the gas is to be
consumed in order to produce light or heat, is the same in my improved
apparatus as those which are in general use.
In witness whereof, I, the said Samuel Clegg, have hereunto set my
hand and seal, this Eighth day of June, One thousand eight hundred