IMPROVEMENTS IN STEAM BOILERS, ALSO APPLICABLE IN PART TO GAS METERS, LAMPS, AND LUBRICATING AND OTHER APPARATUS REQUIRING A CONSTANT LIQUID LEVEL, AND IN PART TO PRESSURE-INDICATING APPARATUS
Year: 1858

page_text: LETTERS PATENT to Alexander Allan, Engineer, Thomas Whimster, Gas
Engineer, and Robert Gray, Gas Inspector, all of Perth, in the
County of Perth, North Britain, for the Invention of "IMPROVEMENTS IN
STEAM BOILERS, ALSO APPLICABLE IN PART TO GAS METERS, LAMPS, AND
LUBRICATING AND OTHER APPARATUS REQUIRING A CONSTANT LIQUID LEVEL,
AND IN PART TO PRESSURE-INDICATING APPARATUS,"
Sealed the 16th April 1859, and dated the 19th October 1858.
PROVISIONAL SPECIFICATION left by the said Alexander Allan, Thomas
Whimster, and Robert Gray at the Office of the Commissioners of
Patents, with their Petition, on the 19th October 1858.
We, ALEXANDER ALLAN, Engineer, THOMAS WHIMSTER, Gas Engineer,
and ROBERT GRAY, Gas Inspector, all of Perth, in the County of Porth,
North Britain, do hereby declare the nature of the said Invention of .
"IMPROVEMENTS IN STEAM BOILERS, ALSO APPLICABLE IN PART TO GAS METERS,
LAMPS, AND LUBRICATING AND OTHER APPARATUS REQUIRING A CONSTANT LIQUID
LEVEL, AND IN PART TO PRESSURE-INDICATING APPARATUS," to be as follows, that
is to say:
This Invention comprises improvements designed for the obtainment
of a constant or nearly constant water level in steam boilers, and also
applicable, in more or less modified forms, in part for maintaining a con-
stant liquid level in various apparatus such as gas meters. lamps, lubricat-
ing and evaporating apparatus, and in part for indicating pressure.

page_text: In one modification of apparatus constructed according to this Inven-
tion for a steam boiler, the feed water is contained in a closed "fountain,"
or reservoir from the bottom of which a pipe or passage conveys the
water into the boiler at a point by preference near the bottom of the latter.
A pipe or passage communicating with the steam space of the boiler enters
the fountain, and dips down to the level or to a point corresponding to the
level at which the water is to be maintained. The two pipes or passages
are fitted with valves and a third pipe or passage, also fitted with a valve,
is provided for refilling the fountain with water when it becomes emptied.
In order that the apparatus may act, the fountain must contain water
above the mouth of the dip pipe, then on the level in the boiler, descending
slightly below the level of the mouth of the dip pipe; steam enters by the
dip pipe into the fountain, and the water it displaces enters the boiler,
and raises the level therein to its proper height; when the water in the
fountain descends as low as the mouth of the dip pipe, the communica-
tions with the boiler must be closed and the fountain be refilled by the
supply pipe.
In a more complete modification of the apparatus than that just
described, two fountains are employed, and one of them is always in
operation, supplying water to the boiler as it is needed. When the water
level in one fountain becomes as low as the mouth of the dip. pipc, its
communications with the boiler are shut off, and those of the other foun-
tain are opened; and to effect these actions simultaneously, the various
valves may be connected. The steam filling the space above the mouth
of the dip pipe in the fountain out of use then becomes condensed, and
the communication with the main water supply being opened, the foun-
tain. refills with water in readiness for supplying the boiler when the
other fountain is emptied. In order that the attendant may know which
fountain is in operation, and if the whole apparatus is working satisfac-
torily, each fountain is provided with a pressure gauge, by preference
constructed as is about to be explained. The gauge consists, according
to one modification of two glass tubes fitted into a horizontal tube or
vessel, and contains air and a liquid, such as water or mercury, and it is
by the space occupied by the air that the pressure is indicated.
steam (or other elastic fluid), the pressure of which is to be indicated,
communicates directly or by means of an intermediate fluid with the
upper end of one of the tubes, this communication being by preference
from below through a' small tube passing centrally up the glass tube.
The pressure acting down one tube forces the liquid up the other tube,
compressing the air in the latter. A scale is marked on or placed against
the tube, and shows the pressure corresponding to any level to which
the liquid is raised. If the fluid pressure in the fountain or vessel com-
The

page_text: municating with the gauge is less than that of the atmosphere, the air
in the further tube expands, and forces the liquid up the nearer tube,
which last has likewise a scale adapted to it to show the intensity of the
vacuum or the pressure below the atmosphere. A marked distinction is
thus made between the range of pressures above the atmosphere and the
range of pressures below the atmosphere, although both are indicated.
by the same instrument, and a glance at the gauges of the two fountains
will inform the attendant of the condition of each in such a way that he
can scarcely make a mistake. This gauge may be modified in various.
ways, provided its essential feature is retained, of indicating pressure.
by the more or less expanded or compressed condition of the air or aeri-
form matter contained in it. With the view of rendering the scale divi-
sions more convenient, a solid or hollow body of a suitable shape may be
inserted in a cylindrical glass tube, or a small cylindrical glass tube may
be used to show the indications, this tube being in communication with
another passage or chamber shaped to correspond with the proposed divi-
sions of the scale. It is not essential to make the entire tube or gauge
chamber of glass, as a glazed slot or opening will be sufficient to see the
indications through.
The improved pressure gauge just described, or modifications. of -it.
may be used or applied for indicating pressure in closed vessels of any
kind. Where only pressure above the atmosphere has to be indicated a
single tube may be used, and if desired a single tube may be arranged to
indicate pressures either above or below the atmosphere by suitably pro-
portioning the aerial and liquid contents.
A modification of the "dip pipe fountain" herein-before described is
advantageously applicable to wet gas nieters. In this case the fountain
consists of a chamber formed against the meter case, and communicating
with the interior of the latter by a pipe or passage below the level at
which the water is to be maintained. A dip pipe or passage communi-
cates with the gas space and dips inside the fountain to about the level
at which the water is to be maintained. The float for closing the inlet
valve is by preference placed in the fountain, and the valve spindle is
passed down a tube, which may be made to act as a dip tube, either alone
or in addition to another dip tube communicating with the inside of the
drum case. The action is the same as that of the apparatus described
as supplied to a steam boiler, and it will be obvious that the water leve!
can be adjusted with the greatest nicety by lengthening or shortening
the dip pipe or passage or passages. In applying the "dip pipe foun-
tain" to open vessels, such as evaporating pans and lamps, the dip pipe
has its top end open to the atmosphere, and it may be observed gene-.
ially, that in applying the "dip pipe fountain" for maintaining a liquid

page_text: level wherever it may be found suitable, the dip pipe must have main-
tained within it, by direct communication or otherwise the same fluid
pressure as acts upon the surface to be maintained at a uniform level.
The "dip pipe fountain" is advantageously applicable to all kinds of
lubricating apparatus, in which it is necessary or desirable to maintain the
lubricating fluid at a constant level. In a. modification of railway axle-
box in which it forms an essential feature it is arranged to maintain the
lubricating fluid. at a level just below the bottom of the journal at the
points where the journal passes through the sides of the axle box, and
the middle part of the journal is enlarged to dip into the lubricating
fluid, or is formed with a central collar instead of outside collars. This
arrangement has the important advantage of avoiding waste of the lubri-
cating fluid.
SPECIFICATION in pursuance of the conditions of the Letters l'atent, filed
by the said Alexander Allan, Thomas Whimster, and Robert Gray
in the Great Seal Patent Office on the 18th April 1859.
TO ALL TO WHOM THESE PRESENTS SHALL COME, wc, ALEXANDER
ALLAN, Engineer, THOMAS WHIMSTER, Gas Engineer, and ROBERT GRAY,
Gas Inspector, all of Perth, in the County of Perth, North Britain, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Nineteenth day of October, in the year of our
Lord One thousand eight hundred and fifty-eight, in the twenty-second
year of Her.reign, did, for Herself, Her heirs and successors, give and
grant unto us, the said Alexander Allan, Thomas Whimster, and Robert
Gray, Her special licence that we, the said Alexander Allan, Thomas
Whimster, and Kobert Gray, our executors, administrators, and assigns,
or such others as we, the said Alexander Allan, Thomas Whimster, and
Robert Gray, our exécutors, administrators, and assigns, should at any
time agree with, and no others, from time to time and at all times there-
after during the term therein expressed, should and lawfully might make,
"use, exercise, and vend, within the United Kingdom of Great Britain
and Ireland, the Channel Islands, and Isle of Man, an Invention for
"IMPROVEMENTS IN STEAM BOILERS, ALSO APPLICABLE IN PART TO GAS METERS.
LAMPS. AND LUBRICATING AND OTHER APPARATUS REQUIRING A CONSTANT LIQUID
LEVEL, AND IN PART TO PRESSURE-INDICATING: APPARATUS," upon the condition
(amongst others) that we, the said Alexander Allan, Thomas Whimster,
and Robert Gray, our executors or administrators, by an instrument in
writing under our, or their, or one of their hands and seals, should par-

page_text: ticularly describe and ascertain the nature of the said Invention, and in
what manner the same was to be performed, and cause the same to be
filed in the Great Seal Patent Office within six calendar months next and
immediately after the date of the said Letters Patent.
NOW KNOW YE, that we, the said Alexander. llan, Thomas Whimster,
and Robert Gray, do hereby declare the nature of our said Invention,
and in what manner, the same is to be performed, to be particularly
described and ascertained in and by the following statement in writing,
reference being had to the accompanying Drawings, and to the letters
and figures marked thereon, that is to say:-
:-
Our said Invention comprises improvements designed for the obtain-
ment of a constant or nearly constant water level in steam boilers, and
also applicable, in more or less modified forms, in part for maintaining
a constant liquid level in various apparatus such as gas meters, lamps,
lubricating and evaporating apparatus, and in part for indicating pressure.
And in order that our said Invention may be properly understood and
carried into effect, we will particularly describe the improvements as
embodied in several examples of their application, referring as we pro-
ceed to the accompanying Sheet of explanatory Drawings, upon which
we have delineated such examples. The same reference letters and
numerals mark the same or like parts in all the Figures.
"
In one modification of apparatus constructed according to this Inven-
tion for a steam boiler, and represented with the boiler in transverse ver-
tical section in Figure 1, the feed water is contained in a closed "foun-
tain or reservoir A, from the bottom of which a pipe or passage B con-
veys the water into the boiler C, at a point, by preference, near the bot-
tom of the latter. A pipe or passage D, communicating with the steam
space E of the boiler C, enters the fountain A, and dips
down to the level F. or to a point corresponding to the
level at which the water is to be maintained in the boiler
The two pipes or passages B, D, are controlled by valves
G, H, and a third pipe or passage I, also controlled, by a valve J, is pro-
vided for refilling the fountain A with water when it becomes emptied.
The three valves G, H, J, are represented as connected for the con-
venience of actuating them all simultaneously by means of a single
handle K.
C.
In explaining the action of the apparatus we will first suppose the foun-
tain A to be partly full of water, and the boiler C to be full up to the
proper level F, the valves G, H, giving access to the boiler, being open,
and the valve J for replenishing the fountain closed. As long as the
water in the boiler does not descend below the level F, the water above.
the mouth d of the dip pipe D in the fountain A is held suspended as it

page_text: "
were, the steam being unable to change places with it on account of the
hydrostatic balance of the water. and steam; but on the water in the
boiler descending slightly below the proper level F, the steam descends
correspondingly in the portion of the dip pipe D in the fountain A, and
escaping at the mouth 'd of the dip pipe, rises in bubbles to the surface
of the water in the fountain A, the water displaced by it flowing thence
by the pipe B into the boiler, C. On the water in the boiler recovering
its proper level F, the water in the fountain A becomes again suspended,
and the flow to the boiler stopped. In practice the feeding action (as
long as the fountain A contains sufficient water) will be nearly if not
quite continuous; tne water in the boiler C will be maintained at a level
(slightly) below the mouth d of the dip pipe in the fountain A, which will
cause such a continuous stream of steam or steam bubbles to flow into
the fountain, as will displace the water therein, and allow it to flow into
the boiler at the exact rate at which the water in the boiler is evaporated.
When the water in the fountain A descends as low as the mouth d of the
dip pipe, the valve handle K must be shifted so as to close the valves G,
H, communicating with the boiler. C; and open the valve J communi-
cating with a tank or well. The steam in the fountain will rapidly con-
dense, and a fresh supply of water will enter the fountain by atmospheric
or other pressure; the valve handle K may then be shifted back, so as to
place the fountain in communication with the boiler, when the feeding
operation will proceed as before. The fountain A 'may be of various
forms and proportions, but it must be constructed to bear the same pres-
sure as the boiler, whilst its position is determined by the water level F,
as the mouth d of the dip pipe D must coincide or nearly coincide with
that level.
In a modification of the apparatus represented in elevation in Figure 2,
and in plan in Figure 3, portions of both Figures being in section, and
which is more complete than that just described, two fountains A, A,
are employed, and one or other of them may always be in operation, sup-
plying water to the boiler C as it is needed. When the water level in one
fountain becomes as low as the mouth of the dip pipe, the communications
of that fountain with the boiler are closed, and those of the other fountain
are opened. The steam filling the space above the mouth of the dip
pipe in the fountain out of use then becomes condensed, and the com-
munication with the main water supply being opened; the fountain refills
with water in readiness for supplying the boiler when the other foun-
tain is emptied. In Figures 2 and 3 a convenient arrangement of valves
is shown, with which all the changes of communication required at one
time may be made simultaneously. Each fountain A has attached to or
formed upon its end a valve chest L, provided with a slide valve and five

page_text: ports or passage openings. Port 1 admits steam by the dip pipe D to
the back of the valve; port 2 (when uncovered by the valve) admits the
steam into the fountain on the water in the boiler descending below the
proper level, the opening of this port or passage 2 into the fountain being
placed in a position corresponding to that level; port 3, when open to
the
cup of the valve, as shown in section, in Figure 2, gives passage to the
water from the fountain by port 4, and the pipe B into the boiler; finally,
port 5 communicates by the pipe 1 with the main water supply. The
reversal of the valve puts port 2 in communication with port 5 for refill-
ing the fountain, whilst port 3 is covered, and all communication between
the boiler and fountain closed. The two slide valves are connected to
a single rack M, which is actuated by a pinion and hand wheel N, the
movement which shifts one slide valve so as to put the corresponding
fountain in communication with the boiler, shifting the other slide valve
so as to obtain the opposite result with the other fountain, and vice
versa. Or the valves may be shifted by means of mechanism actuated
by a timekeeper, or by the engine, and contrived to shift the valves
periodically, such mechanism being regulated to suit the consumption
of water by the boiler.
In order that the attendant may know which fountain is in operation
or in connection with the boiler, and if the whole apparatus is working
satisfactorily, each fountain is provided with a pressure gauge or gauges
as at O, Figure 2, which gauge is by preference constructed as is about
to be explained. The gauge consists, according to one modification, of
two glass tubes fitted into a horizontal tube or vessel, and contains an
clastic fluid such as air, and a liquid such as water or mercury, and it is
by the space occupied by the air that the pressure is indicated. The
steam (or other elastic fluid) the pressure of which is to be indicated,
communicates directly or by means of an intermediate fluid with the
upper end of one of the tubes, this communication being by preference
from below, through a small tube passing centrally up the glass tube.
The pressure acting down one tube forces the liquid up the other tube,
compressing the air in the latter. A graduated scale is marked on or
placed against the tube, and shows the pressure corresponding to any
level to which the liquid is raised. If the fluid pressure in the fountain
or vessel communicating with the gauge is less than that of the atmo-
sphere, the air in the further tube expands and forces the liquid up the
nearer tube, which last has likewise a graduated tube adapted to it, to
show the intensity of the vacuum or the pressure below the atmosphere.
A marked distinction is thus made between the range of pressures above
the atmosphere and the range of pressures below the atmosphere,
although both are indicated by the same instrument, and a glance at the

page_text: two, fountains will inform the attendant of the condition of each in such
a way that he can scarcely make a mistake. This gauge 'may be modi-
cating pressure by the more or less expanded or compressed condition
fied in various ways, provided its essential feature is retained of indi-
cating pressure by the more or less expanded or compressed condition
of the air or aeriform fluid contained in it. Another important feature
of this gauge when atmospheric air is contained in it, consists in the
facility with which the air may be renewed at any moment, the gauge
being easily contrived so that the proper quantity of air may be at any
time tested or re-measured into it, as is herein-after more particularly
explained. With the view of rendering the scale divisions more con-
venient, the tubes may be made of differential calibre, or a solid or
hollow body of a suitable shape may be inserted in a cylindrical or other
glass tube, or again a small cylindrical glass tube may be used to show
the indications, this tube being in communication with another passage
or chamber, shaped with a differential calibre to correspond with the
proposed divisions on the scale. It is not essential to make the entire
tube or gauge chamber of glass, as a glazed slot or opening will be suffi-
cient to see the indications through.
The improved pressure gauges just described or modifications of them
may be used or applied for indicating pressure in closed vessels of any
kind. Where only pressure above the atmosphere has to be indicated,
a single tube may be used, and if desired a single tube may be arranged
to indicate pressures either above or below the atmosphere by suitably
proportioning the aerial and liquid contents.
Examples of our improved pressure gauges are delineated in Figures
4 to 9, on the accompanying Sheet of Drawings, and we have repre-
sented these examples as constructed in the best manner known to us.
The gauge represented in vertical section in Figure 4 is for indicating
vacuum or pressures below the atmosphere, and it consists of a conical
glass tube P, sealed at the top, which is also the smallest end and formed
with a slight lip at the base, which rests on caoutchouc or other elastic
washer on the metal seat Q, being secured to this last by a nut or screwed
ring R, between which and the tube P, another elastic washer may be
interposed. The metal seat Q is fitted with a duplex cock S, and with a
union joint and nut T for attaching it to a bent pipe U; (see also Figure
2,) which last is used to hold water either collected from condensation
or filled in for the purpose. A small tube V rises up the inside of the
tube P to a height somewhat short of the top of the latter internally, and
this tube can be put in communication with the atmosphere by turning
the cock S a quarter round from the position shown. When the cock S
is so placed, the communication with the pipe U is closed, and the gauge
tube P having been previously full of water, a portion runs out by the

page_text: internal tube V, and a quantity of air enters equal to the capacity above
the orifice of the internal tube V, in addition to that filling the internal
tube itself. The air thus introduced or measured is always the same in
quantity or volume, and if desired its quantity may be tested or re-
measured every time the gauge is inspected, and in this way are got rid
of errors likely to arise from change of condition in gauges not so easily.
tested. On the cock S being again turned a quarter round, the commu-
nication with the atmosphere is closed as shown, and that with the foun-
tain or other vessel to which the gauge is applied opened. The pressure
below the atmosphere in this vessel will then be indicated by the expan-
sion of the air in the gauge forcing down the water, the water surface
line marking the exact pressure on a graduated scale placed against the
gauge tube P. The gauge represented in vertical section in Figure 5
is constructed for indicating pressures above the atmosphere, and differs
from that represented in Figure 4 in being without the internal tube,
so that when its three-way cock S is open to the atmosphere, the gauge
becomes filled with air to the depth of the orifice of the cock. When the
cock S is placed to open a communication with the fountain or other vessel
to which the gauge is applied, the pressure in that vessel causes the liquid
in the bent pipe U to rise and compress the air in the gauge, and by its
surface line mark the corresponding pressure on a graduated scale as
with the vacuum gauge previously described. In Figure 6 is represented
in vertical section a double instrument combining the properties of the
gauges represented in Figures 4 and 5, and exhibiting pressure above
the atmosphere in the right-hand tube P¹, and pressure below the atmo-
sphere in the left-hand tube P. The glass tubes P, P', are cylindrical,
but their internal effective cross sectional areas are rendered differential
by means of conical metal pieces W, X, which are also contrived to hold
the glass tubes P', P, in their places as shown, elastic washers being
applied to the top and bottom edges of these tubes. The differential
piece W of the pressure gauge P¹ is solid, but that X of the vacuum
gauge P is made hollow to serve the same purpose as the internal tube
V, in Figure 4, and there is in addition a cup and stop-cock Y for intro-
ducing water for adjusting the quantities of water and air. In the modi
fication of pressure gauge represented in vertical section in Figure 7,
and in front elevation in Figure 8, the actual gauge chamber P¹ is of
metal, whilst the indications are shown in a secondary tube p of glass
communicating with the gauge chamber P¹ at top and bottom.
glass tube p¹ is put into its place from below, being fixed by a screw plug
Z; and made tight by elastic washers..
The
The gauge represented in vertical section in Figure 9 is similar to that
shown in Figures 7 and 8 just described, the gauge chamber P being of

page_text: metal, whilst the indications are shown in a secondary tube p of glass;
it is, however, arranged for indicating pressures both above and below
the atmospliere, being provided with an internal tube V and duplex cock
S, like those shown in Figure 4. The internal tube V, however, only
extends about half way up the gauge chamber P, its height determining
the atmospheric line on the graduated scale.
A modification of the "dip pipe fountain" herein-before described is
advantageously applicable to wet gas meters. In this case the fountain
consists of a chamber formed against the drum case, so as to contain
water above the level at which the water is to be maintained, and com-
municating with the 'interior of the latter by a piper or passage below that
level. A dip pipe or passage communicates with the gas space above
the water line, and, by preference, above the top of the fountain, and
dips inside the fountain down to about the level at which the water is to
be maintained in the meter. The float for closing the inlet valve is, by
preference, placed in the fountain, and the valve spindle is passed down
a tube, which may be made to act as a dip tube, either alone or in addi-
tion to another dip tube communicating with the inside of the drum case.
The action is the same as that of the apparatus described as applied to a
steam boiler, and it will be obvious that the water level can be adjusted
with the greatest nicety by lengthening or shortening the dip pipe or
passage or passages. In constructing gas meters with our "dip pipe
fountain," we combine therewith some minor improvements conducive
to the same end, as will appear in the following detailed description of
two examples of our improved gas meters, represented in Figures 10 to
16 on the accompanying Sheet of Drawings.
The
Figure 10 is a sectional front elevation of a wet gas meter, constructed
with one modification of our improvements; Figure 11 is a horizontal
section as taken along the line a-b in Figure 10; and Figure 12 is a
side elevation in section as along the line c-e in Figure 10. It is un-
necessary for us to describe the old or well-known details of the meter
further than may be required in explaining our improvements.
entrance pipe f communicates by means of a species of rose g, contrived
to prevent the introduction of a fraudulent instrument, with a small valve
box h, opening into a larger rectangular chamber upon the front of the
drum case i. This last chamber is divided by partitions into the fountain
A, the middle chamber j, k, (communicating with the interior of the
drum case i by the usual openings), and the waste water chambers l, m.
The gas has access from the valve box h to a passage j, forming part of
the middle chamber k, and proceeds down à pipe n, answering also as the
overflow pipė, into the waste water chamber .. whence it enters the

page_text: measuring drum by the pipe o. The proper surface line of the water in
the drum case i is marked by the line p-q. The fountain chamber A ex-
tends considerably above the line pq, so as to contain water for
maintaining this level. It communicates with the middle chamber k;
and consequently with the interior of the drum case i, by a passage B,
which we bush with block tin, to avoid its being obstructed by the oxy-
dation of the iron edges of the hole. The fountain communicates with
the gas space in the drum case i, at a point above the top of the fountain
by the dip pipe D, the lower mouth d of which dips in the fountain down
to about the level p-q. The float r, for stopping the ingress of gas
(when there is not enough water in the meter) by the valve s, which
governs the aperture between the valve box h and the passage j, is
placed in the fountain directly below the valve box h, the valve spindle
passing up from it through a tube t, which descends in the fountain to
about the level p-q, and which may serve as a dip pipe. This tube t
also serves as a guide for the float r, which is made with a square eye to
prevent its turning, whilst the tube t is made with concave sides, as
shown in Figure 11, to allow the gas to pass from its mouth up outside
it through the eye of the float. The float is arranged to close the valves,
before the water in the fountain A is emptied quite down to the level
p-q, so that the gas is shut off before the surface of the water in the
drum case can possibly descend below the level p-q. The manner in
which the fountain A, as long as it is full enough, supplies water to make
up for any deficiency in the drum case, arising from evaporation or other-
wise, is precisely the same as the mode of operation herein-before
described in connection with our improved boiler feeding apparatus. In
order to hold the water in suspension in the gas meter fountain A, when
the latter is being refilled, and also to prevent the escape of the gas that
may be above the water in the fountain, the filling tube'w is made to dip
in the fountain below the level p-q, and a pipe a is provided for trans-
ferring the gas in the fountain back into the drum case i, this pipe
opening into the fountain near the top, as shown, and into the drum case
at a point below the level p-q. When the fountain is being refilled,
the pressure of the entering water will force the gas in the fountain,
thence by the pipe x into the drum case. The dipping of this pipe
below the water in the drum case prevents the gas from passing by it
from the drum case into the fountain.
Figure 13 is a sectional front elevation of a wet gas meter, constructed
with another and a simplified modification of our improvements; Figure
14 is a horizontal section as taken along the line a-b, in Figure 13;
Figure 15 is a vertical section as taken along the line c-e, in Figure 13;

page_text: and Figure 16 is a vertical section as taken along the line uv, in Figure
13. Having marked the several details with the same reference letters
as are used for the like details in Figures 10, 11, and 12, it remains merely
to describe the difference between the two modifications of apparatus.
In the second modification of apparatus the middle chamber (marked k
in Figure 10) is dispensed with, the chamber A, the upper part of which
forms the fountain, being extended down below the level of the drum
spindle y, which projects into it. The fountain chamber A communicates
directly with the drum case by the aperture or passage B, which may
be bushed with block tin, as before explained. The passage j communi-
cates with the waste-water chamber 6, and the overflow pipe n com-
municates directly with the drum case, the overflow taking place from it
into the passage j, instead of into it, as in the first modification.
In the second modification, as represented in Figures 13 to 16, the
tube t, through which the inlet valve spindle passes, acts as the sole dip
pipe for the entrance of gas into the fountain to release the water wanted
to make up the level in the drum case. An additional dip pipe may,
however, be introduced, if required. It will be observed that in both
modifications of gas meter the overflow pipe n is placed as forward as
possible, so that if the meter is tilted forward the water will immediately
overflow, and shortly stop the passage of gas by filling the waste water
chamber 7, besides which the dip pipe being behind the overflow pipe, the
water will flow out of the fountain also, and cause the inlet valve s to close.
The waste-water chamber is separated from the waste outlet chamber
m by a partition descending nearly to the bottom, and the passage of gas
under it is prevented by the waste water. To make sure of the communi-
cation being sealed under all circumstances, the partition may be bent,
as shown in Figure 13; or it may be made to dip down into cavity
formed as indicated by dotted lines in Figure 10; or the communication
may be by a bent pipe. The waste outlet tube is also prolonged internally
for the same purpose.
In applying the "dip pipe fountain" to open vessels, such as evaporat-
ing pans, domestic boilers, 'and lamps, the dip pipe has its top end open
to the atmosphere. And it may be observed generally, that in applying
the "dip pipe fountain" for maintaining a liquid level wherever it may
be found suitable, the dip pipé must have maintained within it by direct
communication or otherwise the same fluid pressure as acts upon the
liquid surface to be maintained at a uniform height.
An example of the application of the "dip pipe fountain" to an open
vessel is given in Figure 17 on the accompanying Sheet of Drawings,
this Figure being a vertical section of an ordinary open boiler C with the

page_text: fountain A placed in connection with it by the pipe B. The fountain A
is supplied by the pipe I, the air being allowed to escape at the cock 6.
The dip pipe D is a straight tube introduced. down through the cover of
the fountain, and open to the atmosphere at is upper end. In other
respects the fountain is air-tight. The bottom mouth d of the dip pipe
is situated at about the level F, at which the water in the boiler C is to be
maintained, and as the water in the boiler is used or evaporated it is
supplied by the fountain through the pipe. B, so as to keep the water up
to the level F until the water in the fountain itself descends below that
level.
Figures 18 and 19 are vertical section of two modifications of lamp,
being examples of the application of the "dip pipe fountain for main-
taining the surface of the oil in the receptacle 7 at a constant height F.
In these examples the dip pipes D are open to the atmosphere at their
upper ends, the fountain being otherwise air-tight.
The "dip pipe fountain" is advantageously applicable to all kinds of
lubricating apparatus in which it is necessary or desirable to maintain the
lubricating fluid at a constant level.
!
A modification of railway axle box, in which it forms an essential
feature, is represented in Figures 20 to 23 on the accompanying Sheet of
Drawings; Figure 20 being a front elevation, Figures 21 and 22 vertical
sections, and Figure 23 a horizontal section, each half of Figures 22 and
23 being sections by different planes. Here the fountain A is arranged
to maintain the lubricating fluid at a level just below the bottom of the
journal 8, the middle of which is enlarged, or is formed with a central
collar 9, to dip into the lubricating fluid. The lubricating fluid is applied
to the journal in a box or vessel 10, made with a turned-in lip loosely fitting
the journal to prevent the fluid from being shaken out, whilst the box is
kept up against the journal by blade springs 11. This and similar
arrangements have the important advantage of avoiding waste of the
lubricating fluid.
Figure 24 is a vertical section of a dip pipe fountain arranged in one
of its simplest forms, and comprehending a contrivance to facilitate the
filling of it. A modification of this contrivance has been described in
connection with the gas meters (Figures 10 to 16); it consists of a tube x,
one end of which opens inside the fountain A, near the top thereof, the
other end opening in the vessel or receptacle C, at a point a little below
the level F, at which the liquid is to be maintained. With this arrange-
ment the fountain may be filled through the dipe pipe D, since the liquid
descending by this pipe D will force the air in the fountain down the
pipe, whilst the liquid covering the external mouth of this pipe x will

page_text: prevent the return of air through it into the fountain. If necessary the
pipe and the communication. B may be fitted with valves. This con-
trivance may be adopted in various applications of the dip pipe fountain.
Having thus particularly described our said Invention, and the manner
in which the same is or may be used or carried into effect, we have to
state that we do not restrict ourselves to the precise details herein de-
scribed or delineated, and that we do not claim to have invented every
separate detail herein described and delineated; but that what we believe
to be novel and original, and claim as the Invention secured to us by the
herein-before in part recited Letters Patent, is,―
First, the several combinations of apparatus herein-before described,
taking each combination as a whole.
Second, the system or mode of maintaining a constant or nearly con-
stant liquid level in closed vessels by means of fountains, such as are
herein-before described, land of which the distinguishing feature is the
application to them of pipes or passages communicating with the space
above the liquid surface to be maintained, and dipping down in the
fountains to a corresponding level.
Third, the system or mode of maintaining a constant or nearly constant
liquid level in open vessels by means of fountains, such as are herein-
before described, and in which pipes or passages communicating with
the atmosphere dip down in the fountain to the level corresponding to
that at which the liquid is to be maintained.
Fourth, the arranging and constructing gas meters so that almost the
entire rectangular chamber in front above the waste-water chamber forms
the fountain chamber, as herein-before more particularly described in
connection with Figures 13 to 16 on the accompanying Sheet of Drawings.
Fifth, the placing of the mouth of the overflow pipe in gas meters fitted
with fountains in front of the mouth of the "dip pipe," to insure the
emptying of the fountain, and closing of the inlet valve when the meter is
tilted forward, as herein-before described.
Sixth, the arranging of the valve box and fountain of the gas meter, so
that the float may be placed directly below the inlet valve, and act
directly upon it, as herein delineated and described.
Seventh, the herein-before described modifications of pressure gauges
(for pressures either above or below, or both above and below the
atmosphere), and the application and use in such gauges of an elastic fluid,
such as air in combination with a liquid, such as water, substantially as
herein-before described.
Eighth, the arranging and constructing air-pressure gauges, so that the

page_text: volume or quantity of air used in them may be re-measured or tested with
facility at any time, substantially as herein-before described.
In witness whereof, I, the said Alexander Allan, on behalf of myself
and of the said Thomas Whimster and and Robert Gray, have
hereunto set my hand and seal, this Thirteenth day of April, in the
year of our Lord One thousand eight hundred and fifty-nine.
ALEXANDER ALLAN. (L.S.)
Witness,
EDMUND HUNT, Patent Agent,
28, St. Enoch Square, Glasgow.