CERTAIN IMPROVEMENTS IN METERS FOR MEASURING GAS AND OTHER AERIFORM FLUIDS
Year: 1841

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, we, THOMAS
PECKSTON, of Arundel Street, Strand, in the County of Middlesex, Bachelor
of Arts, and PHILIP LE CAPELAIN, of the same Place, late of Saint Heliers,
in the Island of Jersey, Coppersmith, Brazier, and Tin-plate Worker, send'
greeting.
WHEREAS Her present most Excellent Majesty Queen Victoria, by Her
Royal Letters Patent under the Great Seal of Great Britain, bearing date.
at Westminster, the Fifteenth day of July, in the fifth year of Her reign,
did, for Herself, Her heirs and successors, give and grant unto us, the said
Thomas Peckston and Philip Le Capelain, Her especial licence, full power,
sole privilege and authority, that we, the said Thomas Peckston and Philip
Le Capelain, our executors, administrators, and assigns, and such others as we,'
the said Thomas Peckston and Philip Le Capelain, our executors, adminis-*
trators, or assigns, should at any time agree with, and no others, from time to
time and at all times during the term of years therein mentioned, should and
lawfully might make, use, exercise, and vend, within England, Wales, the
Town of Berwick-upon-Tweed, and in all Her Majesty's Colonies and Plan-
tations abroad, and in the Islands of Jersey, Guernsey, Alderney, Sark, and
Man, our Invention of "CERTAIN IMPROVEMENTS IN METERS FOR MEASURING
GAS AND OTHER AERIFORM FLUIDS;" in which said Letters Patent is contained'
a proviso, obliging us; the said Thomas Peckston and Philip Le Capelain, by
an instrument in writing under our hands and seals, or under the hand and
seal of one of us, particularly to describe and ascertain the nature of our said
Invention, and in what manner the same is to be performed, and to cause
the same to be inrolled in Her Majesty's High Court of Chancery within six
calendar months next and immediately after the date of the said in part recited

page_text: Letters l'atent, as in and by the same, reference being thereunto had, will
more fully and at large appear.
NOW KNOW YE, that in compliance with the said proviso, I, the said
Thomas Peckston, on behalf of myself and of the said Philip Le Capelain, do
hereby declare that the nature of our said Invention, and the manner in which
the same is to be performed, are particularly described and ascertained in
and by the following description thereof, reference being had to the Drawings
hereunto annexed, and to the letters and figures marked thereon (that is
to say):
Our improvements in meters for measuring gas and other aeriform fluids
comprehend four different constructions of apparatus suited to the measuring
of volumes of gas or. other aeriform fluids when passed through them. The
first construction of apparatus has a reciprocating vessel partially immersed in
water or other suitable liquor within a close case, by the vibrations of which
vessel successive volumes of gas are measured and registered. The second
construction of apparatus is on a rotary principle, designed to act without
water or any other liquor in the case, and to measure volumes of gas passed
into four expansible boxes or chambers attached to a rotary valve, which
chambers are successively filled and emptied by the gas as they revolve. The
third apparatus has two expansible boxes or chambers which vibrate upon a
central valve, and in their ascent and descent open and close the inlets and
outlets, by which the gas is received and expelled from the expansible vessels.
The fourth construction of apparatus, has four stationary expansible chambers,
which as they expand and collapse act upon racks that open and close the
valve. And lastly, an improved counting machine, applicable to all these and
other gas meters, for the purpose of counting and registering the successive
rotations or vibrations of the moveable parts, and thereby shewing the number
of volumes of gas which have passed through the apparatus. The several
constructions of these improved meters are shewn in the Drawings hereto
annexed, and will be fully understood by the description thereof, as follows:-
Fig. 1 represents a vertical section of the first construction of apparatus.
A, B, is the outer case of the meter, which may be of cast-iron, or of tin plates,
as most convenient. It is made in two parts, with flanches in the middle,
which can be connected together by means of pasteboard, mastic, or iron
cement joints, and small screws, as shewn, or by screw bolts and nuts. In the
interior of the case are suspended upon the axis G the two reciprocating
chambers or compartments C and D, being connected, into and from which
the gas is to be received and expelled alternately, that is to say, as one
chamber or compartment is filling, the other is constantly emptying itself into

page_text: that part of the outer case which is above the water E, E, (the height of the
water being shewn by a dotted line, and designated also by a tint of blue), and
thence by means of the exit pipe H at top the gas passes to the burners
where it is to be consumed. I is a bent pipe, which conveys the gas into the
meter from a service pipe, street main, or other source of supply; J is another
bent pipe, for conveying the gas from the interior chambers or compartments
C, D, as above mentioned, into the outer case. In the situation in which the
interior part of the meter is exhibited in this Figure, the compartment marked
C is full of gas, and just beginning to empty itself into the outer case through
the slit or exit aperture marked a in the pipe J, represented as open. The
action of the sliding part of the valve which had caused the aperture a to open
to the compartment C had (as will be hereafter explained) also caused the
aperture 6 of entrance to the same chamber to be closed.. And the tumbler p
of the valve within the compartment C, being connected with the tumbler v in
the chamber or compartment D by means of the rods q and u, and the connect-
ing piece r, s, t, which produce a parallel motion, it is evident on inspecting
the Figure that the same action which shuts the aperture of entrance 6 into the
compartment C, and opened the aperture a of exit from the same chamber,
must necessarily shut the opening of exit c from the chamber or compart-
ment marked D, and open the pipe of entrance d into that chamber or com-
partment at precisely the same moment of time. The entrance into and exit
from the respective chambers or compartments are effected by means of the
slide valves K, K, (which are more fully described by Figures 2, 4, 5, 6, 7,
and 8, and the references thereto). As the compartments stand in the Figure
(before explained) the valves K, K, leave open the exit pipe J communicating
with the compartment C, the entrance pipe I into the same compartment
being shut, whilst the exit pipe J from the compartment D is shut, and the
entrance pipe I into that compartment is. open.
The consequence of this
arrangement is, that as the gas enters into the compartment D by the pipe I,
it is escaping from the compartment C by means of the pipe J into the outer
case. The catching piece marked L, which is secured to the centre piece
separating one of the chambers from the other, acts upon the loop o, w, (sce
also Figures 2 and 9,) fixed upon the connecting piece r, s, t, to the upright
part of which at r is attached the rod q, and at t the rod u. The upper parts
of these rods are attached respectively to the tumblers p and v, and work upon
pivots passing through their carriages fixed upon the slide valves K, K, as
shewn in Fig. 2, and more fully in Figures 4 and 5.
Under this arrange-
in which they can be
ment it is evident the rods 7 and u will in all situations
placed be parallel to each other, and lines drawn through the centre of

page_text: the pins which connect the rods q and u to the piece r, s, t, and through
the centres of the pivots near the upper ends of the rods will, also be always
parallel, as must be evident from an inspection of the Figure. As the
compartment. D fills with gas, the catching piece marked L, acting against
the wire marked o, w, at w, draws the piece marked r, s, t, gradually
towards the right hand till such time as the rods g and u attain a vertical
position, which they do not do till the compartment D has become very
nearly full of gas, by which time the compartment C is nearly empty, having
descended into the water so as to occupy nearly, the same position' as the
compartment D represented. in the Figure. The small quantity of gas which
can (when the rods and are vertical) still he received into the chamber
D. causes the tumblers p. and v, by the action of the catching piece L; to fall
from their vertical-positions toward the left, and so soon as that is the case;
from their weight they tumble over into positions directly opposite to those
shewn in Fig. 1, and thus acting (as before observed) simultaneously, the pipe
d which had been the inlet to the chamber Dis by the action of the sliding
part of the valve shut (as will be hereafter explained), and the outlet c from
that chamber opened, whilst the outlet a from the chamber C is shut, and the
inlet 6 to that chamber is opened; so soon as this is the case the compartment
C begins to fill again with gas, and the catching piece L acts against the wire
marked o, w, at o, and draws the piece marked r, s, t, gradually towards the
left hand till such time as the rods g and u attain a vertical position, which
they will not do till the compartment. C is very nearly full of gas, by which
time the compartment D is nearly empty, having descended into the water, so
as to occupy nearly the same position as shewn in Fig. 1. The small quantity
gas which can still be received into the chamber C causes 'the tumblers (by
the action of the piece marked r, s, t, and the rods q and u thereunto attached,
by being also attached to and moving with the tumblers) vand. p to recede
from their vertical positions a little to the right, and so soon as that is the
case (from their weight), they fall over into a position directly opposite to
what they had done prior to the chamber c being filled with gas, that is to say,
into the position shewn in Fig. 1. As the tumblers v and p act simultaneously,
the pipe which had been the inlet to the chamber C whilst it was filling is shut
off, and the pipe which allows the gas to escape into the outer case is opened;
whilst the outlet pipe; from the chamber D becomes shut and the pipe of
entrance is opened into that chamber. Thus one chamber is constantly re-
ceiving the gas from the street main, service pipe, or other source of supply,
and the other is constantly emptying itself into the outer case, from whence the
burners are supplied by means of a pipe connected to the outlet pipe H at top.
of

page_text: In Figure 1 the direction in which the gas travels through the pipes I and J
is designated by arrows, as it is also in the Figures 2, 6, 8, and 9. There are
three holes drilled and tapped into the outer case (when of cast iron); when of
tin, there must be similar openings and a screwed brass boss soldered upon it
for receiving the thumb-screws M, N, and O. By the opening M the water is
introduced into the meter, the opening at N is for drawing off any surplus water,
should it by condensation or otherwise rise above its proper level, which would
cause the meter to measure incorrectly. The opening at O is for drawing
water out of the meter should it require to be removed to undergo repairs, &c.;
when the meter is to be filled (or charged) with water the thumb-screws M
and N are removed and the screw-thumb O is left in its place; the water is
then poured in (by means of a funnel) at M till it begins to overflow at the
opening N, which shews that it then stands at its proper height; the thumb-
screws M and N are then to be secured, and the meter is ready for being used.
In being this. meter, great care must be taken that the bottom be perfectly
level. The upper part of the meter, or that above the water, (which in
Figures 1 and 2 is not colored,) serves as a reservoir for receiving the gas as.
it is discharged from one or the other of the reciprocating chambers, which
reservoir being always kept full of gas, prevents any fluctuation of the lights
at such time as the actions of the valves are changed. Fig. 2 is a transverse
vertical section of the meter. A, A, A, and B, B, B, represents the outer case,
made of cast iron; p or v, the tumbler, with its tongue z, which, as the...
tumbler falls over, strikes against the pins x or y, (as more plainly shewn at
Figures 4, 8, and 9,) thus causing the sliding part of the valve to shut alternately
in each chamber the slit or opening b or a, in the fixed part of the valve, for the:
purpose mentioned when describing Fig. 1. To the tumbler is attached the
rod or wire q or u, in the way shewn in the Figure, each tumbler working
upon an axis or pivot passing through the carriages, (as more plainly shewn
at Fig. 5,) fixed upon the slide valves k, k; in this Figure, s, s, corresponds
with the part marked r; s, s, t, shewn in Fig. 1; it shews also how the rods g
and u are therewith connected; 0,-w, corresponds with the part marked with
the same letters in Figures 1 and 9. L is the catching piece, acting against
the wire o; w, as already mentioned when describing Fig. 1. G, G, is the
axis upon which the reciprocating chambers C, D, move, one half of which
axis rests in a hollow in the lower part of the outer case; the upper half is
received in the same way into the upper part of the outer case, as shewn in
this Figure. J, J, represents the outlet pipe, for conveying the gas from
the interiors of the reciprocating chambers into the upper part of the meter, or
that which is above the water, whence it proceeds through the outlet pipe

page_text: marked H, at top, towards the burners, where it is to be used. The inlet
pipe I can only be shewn in part in this Figure, a portion of it being behind
J, J. Upon the elbows at the foot of the pipes marked I and J, outside of the
outer case of the meter, are fixed the thumb-screws P and Q, by unscrewing
which the water can be drawn off from them, and the gas-way cleared of
impediment, should the water from any sudden or extraordinary pressure flow
over the valves k, k, and fill either of the pipes I or J, so as to stop the
entrance of the gas into or its exit from the meter. Fig. 3 is a front elevation
of the meter, shewing the situation of the registering index, the construction
and mode of operation whereof will hereafter be fully described. Fig. 4 is a
side view of the tumbler, valve, &c., on an enlarged scale, which having been
explained when describing Figure 1, need not be Iwelt upon further in this
place than to remark that p or v represents a side view of the tumbler; k, side
view of valve, with its sockets for receiving the pipes I and J, and the carriage
attached thereto, through which the spindle (marked o, o, Fig. 5,) upon which
the tumbler moves passes; x and y are strong pins fixed upright and firmly to
the sliding piece X, X, which shuts the apertures 6 and d alternately, as was
explained when describing Figures 1 and 2; is the tongue or part which
strikes alternately against the pins x and y, pushing the slider toward the
right-hand or towards the left, as may be required, for shutting the apertures
b or a. The rod marked q or u has already been described when explaining
Figures 1 and 2. Fig. 5 is a view of the tumbler, valve, &c., drawn on the
same scale as Fig. 4, and which, as the corresponding parts in Figures 4 and 5,
are marked with similar letters. Fig. 6 represents portions of the inlet pipe I
and the outlet pipe J, and the upper face of the fixed part of one of the valves
marked K, K. The slit or opening marked c is over the pipe J, leading from
the compartment D, (Fig. 1,) and that marked d is over the pipe I, which
leads into the same compartment. The pipe marked I or J represents the
pipe marked J in Figure 1, which being above the pipe I in this Figure,
prevents that pipe from being shewn. Fig. 7 is a section of the fixed part of
the valve K, K, shewing the groove in which the sliding part X, X, (Fig. 8,)
moves backwards and forwards. Fig. 8 represents a portion of the inlet pipe I
and of the outlet pipe J, and also of the upper face of the fixed part of one of
the valves marked K, K, and corresponding so far with Fig. 6; these parts
require no further description. This Figure, however, represents the upper
face of the sliding piece X, X, in a position that closes the slit or aperture
marked c, and leaves the aperture or slit d open. It shews also the situation
of the pins x and y, against which the tongue marked z (Figures 4 and 5)
strikes, when the tumblers por v fall over, and by which the apertures c and d

page_text: are alternately shut or opened. Fig. 9 represents the lower half of the outer
case of the meter, when the upper part thereof and the internal reciprocating
chambers are removed, so that the plan of the inlet and outlet pipes of the
valves and tumblers, and their appendages for working the same, can be seen
in plan. The situation of the thumb-screws marked N and O, shewn in
Figures 1 and 3, are marked with corresponding letters in this Figure. I is
the inlet pipe, for bringing the gas into the meter; J is the pipe for conveying
the gas from the interiors of the reciprocating chambers into the upper part
of the outer case, or that part of the interior which is above the water. Upon
these pipes, outside of the outer case, is shewn in plan the union joint g, used
upon the upright pipe shewn in Fig. 2. The valves K, K, the tumblers p
and v, with their tongues z, the sliding part of the valves x, x, the striking pin x
(the only one seen in this Figure), the rods q and u, the connecting piece r, s, t,
and the wire marked o, w, having all been fully described when explaining
Figures 1, 2, 4, and 5, do not require further remarks as to the ends they are
respectively and collectively intended to answer.
Fig. 10 is a transverse vertical section of the rotary dry gas meter. A repre-
sents the outer case of the meter, which may be constructed of cast-iron, tin,
copper, or zinc, as most convenient. This being a vertical section of the meter,
when the end is supposed to be removed, shews the inlet pipe B, the valve C,
the hollow clipping piece I, the pipes D, E, F, and G, leading from the valve to.
their respective chambers D*, E*, F*; and G*, the compressers d, e, f, and g,
and the diaphragm (or flexible membrane) d*, e*, f*, and 9*, attached to the
compressers and chambers. The compressors d and fare connected together
by the strong wires or bars a, a, and a*, a*, and the compressors e and g by the
wires or bars b, b, and 6*, 6*. The lengths of these wires or bars respectively
are so adjusted that when the chamber D* and the diaphragm d* thereunto
attached are quite full of gas, and the opposite chamber F* and the
diaphragm f* thereunto attached are quite empty, the said wires or bars
extend from the compresser d to the compressor f. In like manner the com-
pressors e and g are connected together by the strong wires or bars b, b, and
6,6; the length of those bars or wires respectively is so adjusted that when the
chamber G* and the diaphragm g* thereunto attached are quite full of gas, and'
the opposite chamber E* and the flexible material e* thereunto attached are
quite empty, the said wires or bars respectively extend from the compressor e to
the compressor g. The chambers D*, E*, F*, and G* are constructed of tin,
and of the shape shewn in this Figure, and longitudinally in Fig. 11. The
compressors are also made of tin, and of the shape shewn at d, e, f, and g, in.
this Figure, and at d in Fig. 11. The gas enters into this meter by the inlet.

page_text: pipe marked B.in this Figure, which is also shewn at B, Figures 11 and 12.
The mode of constructing and 'fixing which inlet pipe will be fully explained
when describing. Figures 13 and 14, which represent the said inlet pipe drawn
on a larger scale. The gas on entering is received by slits into the different
partitions of the valve C (in this Figure four in number, to correspond with
the four chambers), and over each partition in the said. valve is soldered a
pipe so bent that when tlie internal. part of the meter occupies the position
shewn in the Drawing, the 'pipe D.shall be connected with the chamber D*,
which is directly opposite to the valve C on the right. In this Figure it is
evident that the pipe marked: D is the one open to that division of the valve C
which communicates with the inlet pipe B by the slit already noticed; con-
sequently the gas is filling the chamber D, and causing the flexible membrane
d to distend,..which it will continue to do till that chamber and diaphragm
become filled with gas; as the compressor d is secured to tlie diaphragm'd by
two or more rivets, it is evident that as the chamber D* and the diaphragm d*
become filled with gas, the compressor d is brought nearer to the centre of the
meter, whilst the conipressor f, which is secured to the diaphragm f*, f*, by
two or more rivets. (as will be hereafter described), being connected with the
compressor d by the two wires. or bars a, a, and a*, a*, causes the gas to be
expelled from the chamber F and its diaphragm f*, f*, through the pipe F,
into the lowermost division of the centre revolving valve C, whence it escapes
by the slit shewn (about one-eighth of an inch in width, and three quarters of
an inch in length) into the outer case of the meter, from whence it is conveyed
to the burners or where it may have. to be used by the pipe H, Fig. 11. If
we suppose the centre of the valve to be a fulcruni (it is the centre round
which the different chambers and compressors revolve), by mere inspection of
the Figure it will be seen that the compressor d is much nearer. to the centre
than the compressor f (in the Figure, supposing the compressor f to be
distant from the centre.six inches, then the compressor d is distant from, the
same centre only four inches); the weight therefore of the compressor at f
would (supposing there was not any friction). raise a compressor at d of
nearly one-third more weight, and the consequence would be a quarter revo-
lution of the chambers. Such motion would be accelerated' by 'the levity of
the gas contained in the chamber D* and its diaphragm d. This quarter
revolution will bring the chamber E* into the position which D* occupies in
the Figure; D will occupy the place there occupied by G*, and so on.
Such being the case, it will be evident that the gas entering into the valve
(which valve revolves with the chambers). will enter into that part of it by the
inlet pipe B, which is open to the pipe E, by which pipe the chamber. E*

page_text: and diaphragm e, e, will be filled with gas, and their filling. will cause the
gas to be expelled from the chamber G* and diaphragm g (by means of
the wires or bars b, b, and b, b) through the pipe G, and the slit, in the
valve C open from the same division of the valve to the outer case, to be
conveyed from thence to the burners by means of the outlet pipe H, Fig. 11.
So soon as the chamber E and its diaphragm e, e,.are.quite full of gas,
the chamber Gand its diaphragm will be quite empty, when, from the
reasons, already assigned, the chambers will again inake one-fourth of a
revolution, and so on continuously, whilst the gas passes through. the meter,
as must evidently appear from what has been already stated, and from an
inspection of Fig. 10. If therefore the chambers be of. á specific capacity,
and the diaphragms or flexible membranes are formed so as to require a
definite quantity of gas to distend them fully, an accurate measurement of the
quantity of gas passing through the meter during one revolution will be
ensured. We will suppose, for instance, that each chamber, with the dia-
phragm thereunto attached, when quite filled with gas, contains one-sixteenth
of a cubit foot; it follows that the moveable part of the meter in making one
entire révolution must have allowed four-sixteenths or a quarter of a cubic
foot of gas to have passed through it.. Consequently, if a pinion of ten. tecth
were fixed upon the axis a, a, (see. Fig. 11,) upon which the chambers revolve,
and worked into a wheel of forty teeth, that wheel would make only one
revolution, whilst the internal part of the meter revolved four times; therefore
one revolution of the wheel of forty teeth would indicate one foot. If we
then suppose the pinion of ten teeth (shewn in Fig. 11). to be fixed upon the
axis of the wheel of forty teeth, and that the last-mentioned pinion drives two
wheels, one of one hundred and the other of one hundred. and one teeth
(revolving upon a fixed axis), it follows that in one revolution of the wheel of
one hundred teeth ten feet will be registered upon the dial (as shown in
Fig. 12). The axis of the wheel of one hundred teeth passes, through the
axis of the wheel of one hundred and one teeth, and thereon is fixed the
pointer (as shewn in Figures 11 and.12), which of course revolves with the
one hundred teeth wheel. Now, as the other wheel has one. hundred and one
teeth (it revolves freely upon the axis of the wheel of one hundred. teeth), it
being driven by the same pinion, it is evident that when the wheel of one hun-
dred has made one revolution, the wheel of one hundred and one teeth will fall
one tooth back, or one division on the dial plate. (Fig. 12); .conséquently the
pointer and the wheel of one hundred teeth that carries it make one hundred
revolutions, whilst the wheel of one hundred and one teeth is making one
revolution; therefore one revolution of...the one hundred and one.teeth wheel

page_text: will register one thousand, as figured upon the dial plate (Fig. 12). If we
suppose an opening to be cut through the wheel of one hundred and one teeth
(as shewn in Fig. 12), and at the back of that wheel a small ratchet wheel of
ten teeth be fixed, turning upon an axis attached to the wheel of one hundred
teeth, a striking pin at the back of the wheel of one hundred and one teeth will
move the said ratchet wheel one tooth in one entire revolution of the wheel of
one hundred and one teeth, and thus indicate one thousand, two thousand, three
thousand, &c., to ten thousand. In constructing this counting (or registering
index) a small click will be required to be fixed to the one hundred teeth
wheel to keep the ratchet wheel in its place after being struck by the striking
pin in the one hundred and one teeth wheel till that wheel has made another
entire revolution. With this description of counting (or registering index), and
Figures 11 and 12, its construction and action will be fully comprehended. It
has already been mentioned that the chambers and diaphragms should all bo
made of precisely the same capacity for one size of meter, (that it is to say,) of
one specific size for a three-light meter, of another specific size for a five-light
meter, another specific size for a ten-light meter, and so on,) increasing in size
as the size of the meter increases. In order that there may be no variation in
size (for any one specific size of meter) the best way will be to prepare blocks of
wood shaped exactly to the form of the chambers used in the meter for which
the diaphragm (or flexible membrane) is required, upon which the leathers
are to be stretched and secured down by packthread or otherwise in a groove
made in the block for the purpose, in order that the leathers may be brought
to and retain the exact form that is required. It will be necessary in most
cases to soften the leather with a little olive oil prior to its being stretched
upon the blocks, and whilst upon them it should be dressed with olive oil
and a small portion of tallow, to prevent the action of the gas thereon, and
also to render it perfectly gas-tight. When the flexible membranes (or
diaphragms), which may be made of fine calf skin, of lambs' seconds leather,
or of roan, are formed into shape and prepared as above directed, the com-
pressors are secured to them by rivets; in most cases two rivets will be
sufficient for one compressor. These rivets 'should be made with broad and
flat heads, and under each head should be placed a leather collar of somewhat
larger size than the head of the rivet. The rivets then passing through the
diaphragm (or flexible membrane) are secured to the compressor by rivetting
in the usual way. The leather collars put under the heads of the rivets are
for preventing the diaphragm from being cut or injured by the operation of
rivetting. When the compressors have been attached to the diaphragms in
the way as above described, each diaphragm has to be attached to its respective

page_text: chamber, so that the junction between the chamber and diaphragm shall be
perfectly gas-tight. This is effected by turning over the edge of the chamber,
so as to form a groove of about three-sixteenths of an inch in depth, into which
groove the edge of the diaphragm is to be carefully inserted; the tin is then to
be flattened down with a small wooden mallet (securing the diaphragm in the
first instance at four or more equidistant points), and when the tin is uniformly
flattened down, so as to close up the groove entirely, the junction between the
diaphragm and the chamber will be perfectly gas-tight. The rods or wires
a, a, a, a, b, b, 6*, *, are secured to their respective compressors by means
of soldering. Fig. 11 is a vertical and longitudinal section of the rotary dry
gas meter, in which the parts corresponding with those already described in
Fig. 10 are marked with the same letters of reference, consequently so far
further explanation is not required. In this Figure, however, is shewn the
axis a, a, made of strong brass or iron wire, the brass bosses through which the
axis passes, a small stuffing box at r (the axis carrying a wheel or pinion to
drive the counting or registering index), and the outlet pipe H, with its union.
The train of wheelwork shewn in this Figure forming the counting machine,
and its operation, were fully described when explaining Fig. 10. Fig. 12 is a
front view of the meter, given principally for the purpose of shewing the dial
of the counting machine, which has already been adverted to and explained
when describing Fig. 10. It may, however, be remarked that the outer circle
of the dial plate, numbered from 1 to 10, is a fixed plate secured to the outer
case, and engraved and silvered. The next circle, numbered from one hundred
to one thousand, is engraved and silvered upon the face of the wheel of one
hundred and one teeth, and the figures 4 and 5, which shew themselves
through the opening near the top of the dial, are engraved and silvered on the
ratchet wheel with ten teeth, which works between the wheels of one hundred
and one hundred and one teeth; the said ratchet wheel being divided into
ten equal parts, and numbered from 1 to 10 (indicating thousands), two of
which numbers are always to be seen through the opening in the wheel of
one hundred and one teeth. Fig. 13 is a longitudinal view of the revolving
four-way valve, with the pipe of entrance; a transverse section of which valve
is given at Fig. 14. When referring. to Fig. 13, if attention be directed to
Fig. 10, it will render the explanation more easy. This valve is made of brass
and divided into four compartments, as shewn at Figs. 10 and 14, the end
at a, a, being entirely solid, and to the centre of which the axis a is secured
This valve requires to be turned very truly on the outside from one shoulder
to the other, where the hollow clipping piece I works. The end marked b, b, b,
is an additional piece, as an elongation of the axis and screws upon the valve

page_text: in a contrary direction to that in which the chamber of the meter revolve,
which, in this case, is from right to left; consequently the screw will work
from left to right. Before screwing the piece b, b, b, on, a leather collar must
be inserted into it, so that when screwed up to its place, the leather may press
upon the ends of the divisions, so as to prevent any passage of gas from one
division of the valve to the other. The pipes are marked in this Figure with
the same letters as the corresponding pipes in Figure 10. The clipping piece
I is hollow, and in transverse shape as shewn at I, Figures 14 and 15. After
being filed out to the shape shewn in the two Figures last named, it is ground
so as to make a perfectly gas-tight joint with the revolving valve already
described, and so as to work freely and with little or no friction thereon.
This is effected in the following manner-A piece of brass pipe about three-
sixteenths of an inch more in bore than the exterior of the inlet pipe B, and
about. three inches less in length than the semi-diameter of the meter, is
screwed into the upper part of the hollow. clipping piece I, so that when it is in its
place (as shewn in Fig. 10), it may preserve a perfectly vertical position. The
spiral wire is put over the brass pipe before it is fixed in its position over the
revolving valve; that spring pressing against the outer case of the meter, and
against the upper surface of the hollow clipping piece I, will keep the latter
close down upon the revolving valve, without causing that friction which would
arise were the clipping piece I attached to the inlet pipe B; the 'inlet pipe B
is then introduced through a hole made in the top of the meter into the afore-
said brass pipe, and must be of such a length as to dip into the brass pipe
attached to the clipping piece I about three inches. This done, and the inlet
pipe B being soldered to the outer case, a little tallow or grease must be intro-
duced between the outside of the inlet pipe B and the inside of the brass pipe-
attached to the hollow clipping piece I to the depth of about three-quarters of an
inch all round; to act as a stuffing to prevent any escape of gas from the inlet pipe
Binto the meter without its first passing through the revolving four-way valve.
Fig. 14 is a transverse section of the revolving four-way valve when in the act of
changing its position from that shewn in Fig. 10, in which the corresponding
parts are marked with corresponding letters. The inlet pipe B, the outer brass
pipe, and the surrounding spiral wire spring, having been fully described when
explaining Fig. 13, require no further elucidatory remarks. Fig. 15 is a
representation of the inlet pipe B and its appurtenances, as intended for a
rotary dry gas meter, having six chambers, which must be made on precisely
the same general plan as the one where only four chambers are used; the
action of the meter in each case being similar. In all meters for supplying
gas to more than fifteen lights, it will be advisable to make them with six

page_text: chambers in preference to using only four. Fig. 16 is a transverse section of
the revolving valve for a six-chamber rotary dry gas meter, which, after what
has been said relative to the four-way revolving valve, requires no further
explanation. Fig. 17 is a transverse vertical section of the rotary dry gas
meter, shewing the chambers, &c. at the end opposite to that where the valve
C and the pipes D, E, F, and G are fixed. This section is given for the purpose
of shewing the mode in which the chambers are held together, and how the
axis a, a, (Fig. 11,) is supported. The chambers, after the diaphragms have
been attached to each, are sccured together by means of pieces of tin (marked
in this Figure c, c, c, c,) each about one inch and a half in breadth, by about
two inches in length, each piece being soldered so as to embrace and hold
together two contiguous chambers. After this is done, it will be most con-
venient to solder on the wires or bars a, a, a, a, and b, b, b, b, in the
situations shewn in Figures 10 and 11. Then solder on the cross made of tin
B, B, B, B, to the chambers, as shewn in the Figure, first soldering on at the
centre the brass boss c*, perforated for, the spindle a, a, Fig. 11, to pass through,
which spindle must also be soldered to the said boss. The spindle a, ȧ, should
have upon it two collars, the one at the end next the stuffing. box r distant
from that end just enough to pass through the case of the meter, and to pro
ject about a quarter of an inch beyond the said stuffing box, for the purpose of
carrying the pinion intended to drive the counting (or registering index); the
other collar to be put on the spindle close to the inside of the opposite end of
the meter, so that the internal revolving part may have constantly the same
bearings.
..
The reciprocating dry meter is shewn at Figures 18 and 20, which are
transverse vertical sections of the meter; Fig. 19 is a horizontal section of
the same;
and Fig. 21 is an external elevation of the meter, in which Figures
corresponding parts are marked with similar letters of reference. A, A, is the
outer casing; B, the inlet pipe, which is constructed in the same way as
mentioned when describing the inlet pipe of the rotary dry meter, Fig. 13; C
represents the valve divided into two compartments only, the construction and
action of which will be more fully explained when describing the enlarged
section of it at Fig. 24; D is the inlet pipe to or outlet pipe from the chamber
E, according to the position of the valve C. In the position shewn in Fig. 18,
it is conveying the gas into the chamber E, and distending the diaphragm F.
thereunto attached; the pipe D being open to that half of the reciprocating
valve, the aperture of which is directly under the inlet pipe B, and the hollow
clipping piece K; on referring to Fig. 19, it will be seen that the pipe D; as well
as the pipe G, are in front of the clipping piece K, that covers the apertures

page_text: (which are about one-eighth of an inch in width, and three-quarters of an inch
in length). G is the inlet pipe to or outlet pipe from the chamber II, according
to the position of the reciprocating valve C. In the position shewn in the
Figure 18, the gas is passing from the chamber II and the collapsing dia-
phragm. I into the part of the valve to the right of the partition marked C* in
Figure 24, whence it escapes by the slit or aperture shewn in that Figure,
and marked a, into the outer case, to be thence conveyed by means of the
outlet pipe J to the burners, or where it may be required for other purposes
besides affording light. The compressors f and i are connected together by
the wires a, a, and b, b, (of from one-eighth to one tenth of an inch in dia-
meter), the length of which wires are so adjusted that when the chamber E
and its diaphragm F thereunto attached are quite full of gas, and the opposite
chamber H and its diaphragm I thereunto attached are quite empty, the said
wires shall extend from the compressor f to the compressor i. The chambers
E and H are constructed of tin, and of the shape shewn in these Figures 18
and 20, vertically and horizontally in Figure 19, so that they form a segment
of an ellipse at that part where the diaphragms are secured to them; the trans-
verse diameter in the proportion of six to five of the conjugate is the best shape
for forming and securing the diaphragms to them. The compressors f and i
are also made of tin, and elliptical in shape, the proportionate length of the
conjugate diameter being shewn in these Figures 18 and 20, and the trans-
verse at fand i, Fig. 19. The gas enters into this meter by the inlet pipe B,
and through the hollow clipping piece K (the latter with its brass pipe, spiral
wire, spring, &c. has already been explained when describing Figures 13
and 14. The only difference between the one and the other being in the
width of the clipping piece, which, in Figures 13 and 14, embraces nearly one-
half of the valve, whilst in this instance it embraces only about one-seventh
of the circumference of the said reciprocating valve C), so that in the position
in which the meter is shewn the gas is entering through the slit marked
a (Figure 24) into the chamber E and its diaphragm, whilst the gas is
escaping from the chamber II and its diaphragm into the outer case, and
thence to the burners, &c. by means of the outlet pipe J, Figures 18, 20, and
21. Let it be supposed, then, that the gas continues to enter into the
chamber E till the diaphragm F is fully distended. The compressor f being
secured to the diaphragm F by rivets (as heretofore described when explaining
Fig. 10), and being connected with the compressor i, by the two wires or rods
a, a, and b, b, it follows that the filling of the chamber E and diaphragm F
causes the gas to be expelled from the chamber H and the diaphragm I
through the pipe G into the compartment to the right in the valve C (marked

page_text: C in Fig. 24), and thence by the slit to the right of the said division (marked
a, Fig. 24), into the outer case. L (Figures 20 and 21) is a small brass pulley
wheel, working freely upon the spindle M, M, and kept in its place by the
wires which connect the compressors together, the wires being so placed that
the top one a, a, shall work in the groove of the said pulley L. N, N, Figures
19 and 20, are wires about one-eighth of an inch in diameter, soldered to a
similar sized wire Q, placed above the wire attached to the compressors a, a,
Fig. 20, which wires pass beyond the ends of the chambers E and H, and are
there soldered to a cross wire o, also of one-eighth of an inch in diameter (sce
Fig. 19), with both ends turned out about a quarter of an inch, which ends bear
occasionally on the slide p, p, and occasionally on the slide p, p, fixed inside
the back of the outer case of the meter, as seen in Figures 19, 20, and 22.
These slides are made of brass. In the position in which the chambers are
shewn it will be seen that the diaphragm I, I, is not quite at the bottom of the
chamber H; therefore the bent end of the wire O is not yet ready to slip over
the end of the slide P, P, which it will do when the diaphragm F is fully
distended (or when the chamber E and diaphragm F are quite full of gas),
for then the chamber II will, from the preponderance of the compressor i and
diaphragm I (for the reasons given when explaining Fig. 10) descend and carry
the spindle M, M, and the valve C, Figures 18 and 19, along with it suffici-
ently so as to bring the slit in the valve C to the right (marked a, Fig. 24,)
directly under the hollow clipping piece K, and the slit shewn in the Figure as
under the said clipping piece (marked a*, Fig. 24,) to the left of the said
clipping piece. On such change of position, the gas entering by the pipe B
will pass through the clipping piece K, and through the slit in the valve C at
a, into that portion of the valve marked C*, Fig. 24, and thence by the pipe G
into the chamber II, till that chamber and its diaphragm I are both filled with
gas. In Fig. 22 the cross wires O, O, are represented by dotted lines. It
must be borne in mind that the bent ends alone of the wire O rest upon the
slides P, P, or P*, P*. These bent ends are represented in Fig. 22 by strong
dots, which are designated in that Figure by the letter C, d, c, d, and **,
*d*. When the wire O is in the position shewn in Fig. 19, the bent end of it
c is as shewn at Fig. 22, above the slide P, P, and the other bent end at d; but
when c has been pushed forward to c*, it slips over the end of the slide P, P,
and is carried down to **, thereby raising to d, ready to work upon
the opposite slider marked P*, P*, in Figures 19, 20, and 22, and so on,
alternately. Hence it will be evident, that while the chamber E and its
diaphragm F are filling with gas, the chamber II and its diaphragm I will be
emptying the gas into the outer case, and so on, vice versâ, continually, so long

page_text: as the supply of gas to and passage thereof from the meter continues. A little
loose wool or two small pieces of sponge must be placed in the bottom of the
outer case to break the fall of the vibratory chambers, which would, if not so
guarded against, cause an unsteadiness or undulation of the lights every time
the chambers struck against the bottom of the outer case. Under this
arrangement the power. of propelling the wire O is equable, and the only
resistance against the diaphragms (or leathers) arises from the slightly elevated
position of each of the chambers E and H. If the chambers E and H be
each of the same capacity, and the diaphragms F and I are so formed as each
to require a definite quantity of gas to distend them fully, an accurate measure-
ment will be ensured. If it be supposed, for instance, that cach chamber and
the diaphragm thereunto attached, when quite filled with gas, contain one-
sixteenth part of a cubic foot, it follows that.to fill the chambers E. and I and
distend their respective diaphragms will require one-eighth of a cubic foot. To
register the quantity of gas which may pass through the meter, let a piece of
tin (marked e, e, Fig. 20), about three-quarters of an inch in width, be soldered
to the chambers E and H, and thereon let a loop of wire of one-eighth of an
inch in diameter (marked g, h, i, in Fig. 20) be firmly fixed. That loop as
a matter of course will change its position, as the positions of the chambers
are changed. Then let a moveable wire j, k, (represented in the vertical
section, Fig. 23,) also about one-eighth of an inch in diameter, and two and
three-quarters inches long, with a pin l, be firmly fixed at the lower end thereof
atk (or which may be effected by making the wire j, k, sufficiently long, that
it may be bent at k to produce the piece marked 7, as at Fig. 23,) of sufficient
length to work within the loop g, h, i, shewn at Fig. 20; it is evident that
when the chambers E and H change their positions, the said loop will either
at g or i strike against the pin 1, (moveable upon a centre on the piece m,
Figures 22 and 23,) at the top of which is placed the slight steel spring n,
turned up at the end to catch upon the teeth of the ratchet wheel p, Figures
22 and 23, which spring n will move that ratchet wheel p one tooth towards
the right (causing the said wheel to revolve from right to left) during each
downward motion of the chamber E, passing over the next tooth in the descent
of the chamber H, consequently counting one tooth for a double motion, or
whilst measuring one-eighth part of a cubic foot of gas. If then the ratchet
wheel be made with eight teeth, it is evident it will make one entire revolution
for eight up and eight down strokes of the pair of chambers, thus shewing
that one cubic foot of gas has passed through the meter. This ratchet wheel
is fixed inside of the outer case of the meter and supported by the piece
marked q, Fig. 23; the axis t, t, passing through the small stuffing box r, and

page_text: projecting as far as t, carries upon it, outside the stuffing box r, the pinions of
ten teeth, which pinion works into two wheels, one of one hundred and the
other of one hundred and one teeth, as already described when explaining
Figures 10, 11, and 12, in precisely which way the wheel-work is constructed
for working the dial, pointer, &c., shewn at Fig. 21. It will be necessary to
state here that the dial of the reciprocating wet gas meter, shewn upon Fig. 3:
of the Drawings attached to this Specification, is precisely similar to the dial,
pointer, &c., exhibited in Fig. 21, and the action of the wheel-work thereof
is produced in the same way, by means of a striking piece, similar to g, h, i,
Fig. 20, attached to the reciprocating chambers shewn in Fig. 1, for the
purpose of striking against the pin 1, which works through an opening in the
outer case (as shewn in Fig. 3). The bearer m, the moveable lever j, k, the
spring n, the ratchet wheel p, and the pinion s, being fixed outside of the outer
case, and enclosed in a box (represented as partly broken away, for the purpose
of exhibiting the moveable lever, and the hole in the outer case through which
the pin works, secured to the outer case by screws and a pasteboard or other
joint to make it water-tight: hence the lever j, k, and its appendage / work in
water contained in the box outside of the meter, which is always kept full by
the water inside the meter passing through the hole in which works, thus
rendering any stuffing or packing to prevent the escape of gas unnecessary.
In Fig. 20 is shewn the situation of the small brass wheel L, the upper wire
Q, to which the wires N, N, carrying the wire O are fastened, the slides P, P,
and P*, P*, and the part e, e, g, h, i, for moving the lever j, k, with its pin l.
Fig. 22 represents the inside of the back of the reciprocating dry meter, with
the slides P, P, and P*, P*, the moveable lever j, k, the block on which the
said lever works m, the steel spring n, and the ratchet wheel of eight teeth p.
In this Figure is also shewn by dotted lines the situation of the wire O
(Fig. 19) a little before, at the time, and directly after the change of stroke.
Fig. 22 represents a longitudinal vertical section of part of the outer case
of the reciprocating dry meter A, and sections of the moveable lever j, k,
and its pin l, of the brass carriage on which it works m, of the ratchet
wheel of eight teeth p, and its axis t, t, of the cock or bearer for supporting
the axis t, t, inside the outer case 7, of the small stuffing box r, and the pinion
of ten. teeth s, for driving wheels of one hundred and one hundred and one
teeth, as already mentioned when describing Fig. 18. The valve C is about
an inch diameter, and its length is about an inch and a half. It is like that
before described at Fig. 13, excepting that instead of four compartments it has
but two, and that the inlet pipe is behind instead of being in front of the pipes
which communicate from the valve C with the chambers E and H. The

page_text: hollow clipping piece K is in plan from outside to. outside half an inch, by
three-quarters of an inch. and is formed and connected with the inlet pipe B,
Fig. 18, in the manner as 'described when explaining. Figures. 13 and 14. The
dimensions given when explaining Figures 18 and 24 inclusive are under the
supposition that Fig. 18. is. drawn one-half, the full size, a. size which will
answer exceedingly well for measuring the quantity of gas. consumed where
from one to three full-sized.argand gas burners are used.
Our. fourth construction. of meter.is intended to act on the dry. principle;
and has four expansible chambers placed stationary within a case, as shewn, by
the following Figures of the. Drawing: Fig. 25; is, a transverse, horizontal
section of the meter, taken. through the dotted..line J, K, in Fig. 27, which
is. a vertical. section of the meter. The section, Fig. 25, is given for the
purpose of shewing. two pairs of racks, a, a,. and, a; a", and b; b, and b*; b
which drive the wheel I. and upright spindle, P, P, with. its; revolving
piece Q (Figurés: 27 and 34), at the upper: end of which spindle; P; P, above
the stuffing box R, (see Fig. 27;) is fixed a pinion h. of ten. teeth..for driving
two wheels, one of one hundred and the other of one hundred and one teeth,
in the way which. has already been fully described when explaining Fig. 10.
The dial to be used with this meter to be precisely similar to that shewn.at
Fig. 12, the mode of construction of which has been described when explain-
ing, that Figure. The outer case of: this meter may be constructed of.cast-iron,
tin, copper, or, zinc, as most convenient, the flange round the top of which is
represented at A, A, A, A, and to this the blank-flanch or lid 'L, M;-(Fig. 27)
is secured by means of nuts and screws and a pasteboard or other joint, so.that
the junction may be perfectly gas-tight. So far as the chambers, diaphragms,
and compressors shewn in this. Figure, and in Figures 26 and 27, are con-
cerned, they are precisely similar in all respects to those shewn at Figures 10;
11, and 17, the said chambers, diaphragms, and compressors being prepared,
made, and put together agreeably to the directions. given when explaining
Fig. 10 already referred to. The chambers, diaphragms, and compressors. are
marked with corresponding letters in Figures. 25, 26, and 27, to those used in
Figures 10, 11, and .17, for the sake of easy reference. Fig. 26 is a transverse
horizontal section. of this dry meter taken through. the, dotted line N, O, in
Fig. 27. This, section is given for the purpose of shewing the. chambers;
diaphragms, and compressors, and the pipes D, E, F, G, which convey the gas
from the lower part.of the fixed valve C at top, the gas. being, first brought
into the upper part of the said valve by the pipe B, and from thence passes to
the chambers D, E, F, and G, in succession as the upright spindle P, P, is
with its revolving piece. Q (Eig. 34) driven round by the action of the racks

page_text: a, a, a, a, b, b,"b*, 6*, (Figures 25 and 27,) upon the trundle wheel I, as will
be more fully explained when 'describing the action of this meter. Fig. 27
is a vertical section of the meter, taken nearly through its centre, in which is
représented the chambers F* and D*, with their respective diaphragms f* and
d, and compressors f and d, also the compressor g, and diaphragm g*. The
trundle wheel I, the racks a, a, a, a*, and b, b, 6, 6*, and the pipe B, for
bringing the gas from the service to the meter, which pipe is connected with
the upper part of the stationary valve C, from the lower or divided 'portion of
which proceed the pipes D, E, F, G, (seen best in Fig. 26,) for conveying the
gas into the respective chambers D*, E*, F*, and G*, (Fig. 26,) two of which
chambers' only, (that is to say,) D* and F*, arè shewn in Fig. 27. The top
valve C is drawn full size for a ten-light meter at Fig. 37. The lower fixed
valve C is shewn in section, full size, for a ten-light 'meter at Fig. 36; à plan
of the same is given at Fig. 35, and a plan of the revolving piece Q, with an
opening therein, as shewn at Fig. 34. The Figure 27 further represents the
pipes D and F, which convey the gas from the top valve C to the chambers
D and F, and also. the pipes D, D, and F, F, which convey the gas from
the chambers D and F.to the lower valve C*, whence it escapes (there not
being any top to the lower valve C*) into the outer case, to be conveyed from
thence to the burners where gas-light is required, or for supplying gas for any
other purpose, to which it is applicable. On observing the valves in this
Figure (and which will be more clearly seen on referring to Figures 36 and 37),
it will be noticed that the opening in the revolving piece Q is in the top valve
over that partition of the fixed part of the valve C which leads by the pipe D.
into the chamber D; the said revolving part shutting off all communication
from the other three divisions in. the fixed part of the valve C. The bottom
face of the said revolving piece Q is ground, as is also the upper part of that
part of the valve, which is divided, so that in traversing the revolving piece Q
shall make à gas-tight joint over the lower part of the valve, except where the
opening in the revolving piece Q is situated; and this remark holds good with
respect to the lower valve C and its similar revolving piece. It will be
further seen that the opening in the revolving piece Q is in the bottom valve C*
over the partition of the fixed part of the valve C*, which communicates by
means of the pipe F, F, with the chamber F*, and hence that as the chamber
D* is filling, it will, by the thrust of the racks a, a, a, a, (which connect the
compressors d and f together,) cause the chamber F to empty itself by means
of the pipe F; F, through the valve C* into the outer case. Figures 28 and 29
are plans of one of the racks for a ten-light inéter, drawn full size, supposing
the upper side of the case in which, it is fixed to be removed (as seen at Fig. 30

page_text: and in edge view at Fig 31. These are also all drawn full size for a ten-
light meter. a, a, a, a, is the lower half of the case for containing the rack,
marked b, b, which is pushed forward by means of a slight spring of brass or
steel c, c, so that the teeth of the rack shall protrude from the case, as shewn
in Fig. 30, and lay hold of the teeth of the trundle wheel I when the rack a, a,
is moving from right to left (see Fig. 25); the teeth of the rack a*, a*, which
work at the opposite side of the trundle wheel I, being placed in a contrary
direction to the teeth on the rack a, a, run over the teeth of the said trundle
wheel I, the rack b, b, falling within the case at a, a, a, a, Fig. 30. This
action will, of course, be reversed when the chamber F* is being filled and the
chamber D* is emptying, a*, a*, being then the propelling rack, whilst a, a, is
quiescent. In Fig. 25, in like manner the rack b, b, is the propellor when the
chamber G is filling, and the rack 6*, 6*, is quiescent; also when the chamber
E is filling, the rack 6*, *, is the propellor and the rack b, b, quiescent. Near
the end of each rack is cut an opening marked *, through which openings
and the outer case pass rivets, which secure the outer case to the wires rivetted
to the compressors. These rivets or pins prevent the racks from proceeding
further out of the outer case a, a, a, a, than shewn in Fig. 30. When the
rack is quiescent, the spring c, c, gives way and allows the rack to be received
entirely within the case a, a, a, a, Fig. 30. Fig. 29 is a representation of the
rack without its case, drawn full size, for a ten-light gas meter. Fig. 30 re-
presents the rack enclosed in the case, as it appears when acting upon the teeth
of the trundle wheel I, to propel it onwards (see Fig. 25), in which a, a,
represent portions of the wires for connecting the racks to the compressors.
Fig. 31 is a transverse vertical section of the rack b, b, and of its case a, a, a, a,
with the spring c, c, for causing the teeth of the rack to project to a proper
distance from the case, so as to lay hold of and work upon the teeth of the trundle
wheel I, beyond which distance they are prevented from projecting by the
rivets passing through the case a, a, a, a, and the slits in the racks. It will
be seen by referring to Fig. 25, that during the time the chambers G* and D*
are filling, the racks b, b, and a, a, are both working into the teeth of the
trundle wheel I at the same time, and that to fill the said chambers entirely
the wheel I will make exactly one-half of an entire revolution, or one-fourth
of a revolution for the filling of one chamber; care must therefore be taken
to effect such object by the adjustment of the working circumference of the
trundle wheel 1 with the distance the compressors respectively move through;
for on the action of the trundle wheel the motion of the axis of the shaft P, P,
Fig. 27, upon which it is fixed, depends; and as that shaft carries with it the
revolving pieces of the upper and lower valve Q (Fig. 34), the opening in the

page_text: valve c being nearly the size of the partitions a, b, c, or d, respectively, in the lower
portion of the fixed parts of the valves (as shewn in Fig. 35), it must never be
fully open to more than one at a time of these openings (or partially to two).
It is therefore evident that if the trundle wheel and racks be not accurately ad-
justed so as to cause the revolving piece Q to make exactly one revolution during
the time that the four chambers are successively filled, it will overrun the divi-
sions marked a, b, c, d, (Fig. 35,) and ultimately prevent the meter from acting.
Fig. 32 is another modification for producing a direct rotary motion from an
alternate rectilinear motion, which may be used in lieu of the method exhibited
in Figs. 25, 28, 29, 30, and 31, already explained. In this Figure the racks
a, a, a, a, b, b, b, 6*, are plain pieces of brass about one-eighth of an inch
in thickness, worked to the forme shewn, and rivetted to the wire k, k, which
is secured to the compressor d, d,
the flat-headed rivet h passing through
the diaphragm d*, d*, the leather collar c, c, to prevent the diaphragm from
being cut, and the compressors d, d, to which it is rivetted, as shewn at j, for
which purpose the rivets must be made of very soft malleable iron or copper.
The other end of the rack is rivetted to the wire l, l, which is connected to the
compressor ff, and the diaphragm f*, f, by means of the rivet g and the
leather collar e, e, the rivet g being secured at i. It is evident from inspection
that if the rack a, a, be pushed from right to left (supposing the wheel to be
furnished with fixed teeth), the teeth of the rack a, a, would lay hold of the
teeth in the wheel I, but would not be able to push it round, as the teeth in
the opposite side of the wheel could not pass over the teeth in the opposite rack
a, a; to get over this difficulty the teeth of the wheel I (three of which are.
marked thus *) are each moveable on a pivot, and are pressed forward by.
means of a small steel or other spring behind each tooth, to such a distance.
(a stop to each tooth preventing them from being thrown out too far) that the
rack a, a, in moving from right to left shall act upon them, causing the
wheel I to revolve from left to right; consequently, as the teeth thereof come:
in contact with the opposite rack a*, a*, they will fall back, and thus pass,
over the teeth of the rack a*, a". The action of the racks b, b, and *, *,
being precisely similar, require no further explanation. We do not, however,
confine ourselves to either of these methods of producing a direct circular
motion from an alternate rectilinear one, considering ourselves at liberty to
adopt various other methods for effecting a similar purpose. Fig. 33 is a
vertical representation of the wheel and racks exhibited in Fig. 32, in which
corresponding parts are marked with corresponding letters of reference.
Fig. 34 is a representation of the upper surface of the revolving part of the.
valves Q, shewing the opening c for admitting the gas to the different divisions.

page_text: of the valve, and the slit a for å pin in the upright axis P, P, to fall into, for
the purpose of ensuring the revolution of the piece Q with the axis P, P,
instead of the axis being made square in that part. The piece Q should fit
quite free upon the axis P, P, so as to lay smooth and flat upon the lower part
of the valve in all positions during its revolution. Fig. 35 is a section of the
lower portion of the fixed part of the valve, to which the upper part is screwed,
as:at a, a, Fig. 36, and 'c, c, Fig. 37. The face of the lower portion of the
fixed part of the valve requires to be ground and fitted so that the revolving
piece Q(the face of which must also be ground) may work smoothly thereon,
so as to be gas-tight. Fig. 36 'is a vertical section of the lower valve C*,
(full size for a ten-light meter), shewing how the gas passes through it from
the discharging chamber into the outer case, from whence it is conveyed to
the burners by means of the outlet pipe H; this valve consists of two pieces,
(besides the revolving piece Q), an upper and a lower one, which are connected
together by means of the screw shewn at a, .a. In this Figure is shewn a
portion of the vertical spindle P, P, and a vertical section of the revolving
piece Q. Eig. 37 is a vertical section of the upper valve C, (full size for a
ten-light meter,) shewing how the gas enters by the pipe B into the upper part,
and passes through the opening c in Q into the chambers by means of the pipes
D, E; &c., as the opening in Qmay be over the division in the lower fixed part of
the valve leading to each chamber. The remarks relative to the upper surface
of the lower portion of the fixed part of the lower valve, 'and the revolving
piece Qare applicable to the same in this valve. The upper part of this valve
is secured to the lower by means of the screw joint, shewn at c, c. In this
Figure a portion of the vertical axis P, P, and'a vertical section of the revolving
piece Q, are shewn. In this valve there is a stuffing box R secured to the
upper part by the screw joint e, e, and one at the bottom R*, secured to the
lower part of the bottom by means of the screw joint o, o. These stuffing
boxes are to be packed with tallow or grease, so as to prevent the escape of
gas round. the spindle or vertical revolving axis P, P.
Having now described the different parts of which the fourth construction of
dry meter is composed, it will be understood that the chambers D, E, F,
and G, are all stationary, and that by the action of the spindle P, P, Fig. 27,
which is made to revolve by the racks answering the same purpose as the
wires a, a, a, a*, &c., described in Fig. 10, and the trundle wheel I, the
filling of the chambers is registered. Taking, therefore, the situation of the
chambers, as shewn in Figs. 25, 26, and 27, the action of the meter may
traced as follows, bearing in mind, however, that when the revolving piece Q
in the top valve C has its opening over c (Fig. 35), the opening c in the.

page_text: revolving piece of the bottom valve-C will be over the division b (Fig. 35);
consequently, in all positions, when the opening in the top valve is so situated
as to allow the gas to enter into a filling chamber, the opening in the revolving
piece Qwill always communicate with the emptying chamber, which is directly
opposite to the filling one, and thereto connected; by means of the pair of racks
and wires. This premised, if it be supposed the chambers. D*sand G. are
filled with gas; when that is the case the opening-c in the revolving piece Q
will have been brought fully over.. the-division of the upper-valve, leading into
the chamber E, and the opening c in the revolving piece Q directly over the
division in the lower valve, which communicates, with the chamber G. Hence,
as the chamber E fills, the chamber, G will be emptying, and the racks b, b,
*,*, altering their position, will cause the trundle, wheel, with its axis P, P, to
revolve, carrying with it the, piece Q, so that by the time the chamber G* is
quite empty, the chamber E* will be quite full of gas, and the aperture Q will
begin to open over the pipe leading into the chamber. E,, of course bringing
the opening Q in the lower valve into communication with the chamber D*;.
when the chamber F* begins to fill, and the chamber D* to empty itself, and
so on continually whilst there is a supply of gas into or abstraction of gas from
the meter. If, therefore, the chambers are each of a specific capacity, and
the diaphragms are so formed as to require a definite quantity of gas to distend
them fully, an accurate measurement will be ensured for precisely the same
reasons as were stated when explaining Fig. 10.
.
Lastly, -we-desire-it to-be understood that we-do-not-intend-to-confine-our
inventions precisely to the forms or arrangements of all the parts shewn in the
accompanying Drawings, as many of them- may; be varied-without deviating
from the principles of construction and mode of operating explained above.
But we claim,
Firstly, the general features of the double-chambered vibrating meter, with
its pipes for conducting the gas, and the mode of working the valves, as set
out and explained in reference to the first-described construction of meter.
Secondly, the mode of collapsing the expansible chambers of the rotary dry
meter by means of rods connecting the compressors of the opposite chambers,
so that the gas from one chamber shall be expelled by the act of filling the
other chamber, and from the gravity of the descending and lower empty vessels,
and the levity of the ascending and upper filled vessels, a rotary movement is
produced, by which the induction and exit valves for the passage of the gas-
are opened and shut.
Thirdly, the vibratory dry meter, the expansible chambers of which are
alternately collapsed and expanded by compressors and rods, in a similar man-

page_text: ner to those described under the second construction, and by the action of
which the valves for the entrance and exit of gas are worked.
Fourthly, the rotary action of the central inlet and outlet valves, produced
by sliding racks acting upon a toothed wheel connected with the valves, the
movements of the racks being produced by the expansion and contraction of
the chambers of the meter, through which the volumes of gas pass.
And fifthly, the novel construction of counting machine, by which the filling
and emptying of the chambers of gas meters may be registered, and conse-
quently the number of volumes passed through the meter accurately known.
In witness whereof, I, the said Thomas Peckston, have hereunto set
my
hand and seal, this Twelfth day of January, in the year of our
Lord One thousand eight hundred and forty-two.