of Gases and Vapors, and for Analyzing the same.
Year: 1884

page_text: of Gases and Vapors, and for Analyzing the same.
I FRIEDRICH Lux, of Ludwigshafen-on-the-Rhine in the Kingdom of Bavaria
and German Empire, Civil Engineer do hereby declare the nature of my invention
for "AN IMPROVED METHOD OF AND APPARATUS FOR ASCERTAINING THE SPECIFIC
WEIGHT OF GASES AND VAPORS" to be as follows: —
This invention relates to an improved method of, and apparatus for ascertaining
the specific weight, or gravity, of gases and vapors, and may, in some cases, also
be employed with advantage in ascertaining the pressure of such gases, or vapors.
Heretofore, the specific weight of vapors, or gases, was ascertained either by
means of simply weighing them, or by measuring the speed of their outflow
(as proposed by Bunsen, and Schilling), or by making use of the principle of
communicating tubes (as proposed by Recknagel).
But the disadvantage of all these said former methods of determining the
specific weight of such gases and vapors is that they require a certain length of
time for each trial and do not allow of examining a current of gases with regard
to its specific weight, or its pressure, in continued succession by simply reading the
same from a scale, or graduation, and thus a method by the use of which the said
former disadvantage could be dispensed with, must appear to be of great value in
stating the specific gravity of gases or vapors.
The method forming the subject matter of this application is based upon the
principle according to which the weight, or gravity, of a body in gas or vapor
appears less than when in a vacuum by the weight of the quantity, or volume, of
the gas or vapor displaced by the said body, that is to say:-
Suppose a body of a certain volume, such as a hollow thin-shelled glass globe,
to be weighed, first, within a vacuum and, then within gases, or vapors, of different
specific gravities. In the first instance its absolute weight will be ascertained,
while in the other instances its weight less the weight of the gaseous or vaporous
particles displaced will be ascertained, and by these means the specific gravity of
the said gases or vapors may readily be arrived at.
In order to find out the apparent weight of the said body under different
conditions I provide apparatus as will be described more particularly hereinafter,

page_text: According to the said invention I may secure to one end of a suitable scale-beam
a body of relatively large volume and small weight (say a hollow thin-shelled
glass-globe), and to the other end of the said beam an equiponderant body of high
specific weight (say platinum, or other suitable metal) to balance or equilibrate the
said glass-globe. Now, if this device has been adjusted within a vacuum so that
the scale-beam will assume a horizontal position, then upon the admission of gases
the said glass-globe having a relatively enormous volume, will apparently become
lighter than the small metallic body so that the point of gravity will be shifted,
whereby the scale-beam cannot maintain its horizontal position any longer.
I may suspend the glass-globe, or body, by means of a delicate spring, say for
instance a spiral spring, in accordance with the varying weight or gravity; the
glass-globe will thus exert a greater or smaller strain on the spring and will, in
consequence, hang lower or higher as the case may be.
I may connect the glass-globe with a body floating in some suitable liquid, both
bodies being connected by means of some material of small sectional area, such as
a thin glass-tube, a strip of metal, a wire, hair, thread or the like. In case of
some flexible material, such as hair, thread or thin wire being used for making the
connection, it will be necessary also to provide a pulley, said pulley being dispensed
with when some rigid material is employed for the purpose.
The said device being arranged in a vacuum the glass-globe will apparently
become lighter when gases are admitted; the hydrostatic equilibrium is thereby
suspended, and the body floating in the liquid, will sink when a pulley is employed,
because, in this case, the glass-globe acts as a counterweight (-) but when
employing the floating arrangement the float will rise, the glass globe in this
instance acting as a direct weight (+).
The weight of gases being in inverse ratio to the pressure that is being exerted
on the same, it is obvious that an increase or a decrease of such pressure will cause
the glass globe to apparently become lighter or heavier, respectively, and thus to
indicate such pressure.
Supposing that I designate the point indicated by the apparatus when placed in
a vacuum, with 0, and the point indicated in an atmosphere of 15° Celsius and
760 millimeters mercury pressure, with 1, then the scale between 0 and 1, and also
beyond 1, may be divided at will. The devices described being very convenient
for being surrounded with a glass or other transparent receptacle so that they can
be brought into contact with any desirable gases or vapors of any desired
pressures, it will be understood that the specific gravity or pressure of the said
gases or vapors may be read off directly from the scale.
The gases or vapors being allowed to pass continually through the receptacle, the
indications may be read off at any moment, no further manipulation being required
for the purpose.
An apparatus particularly well adapted for employing the above described
method and practically intended for stating the specific gravity of illuminating
gas, comprises a glass-receptacle about 40 centimeters high and about 7 centimeters
wide closed by means of a closely fitting stopper, and provided with laterally
arranged inlets and outlets for allowing the gas to be examined, to pass through
the apparatus. This receptacle contains the measuring device, the latter consisting
of two glass globes connected with each other by means of an intermediate strip,
the measuring apparatus floating in distilled water, petroleum, or any other suitable
liquid.
The said globes are hollow one being filled with air and the other with water,
mercury, or the like, in such a manner as to cause the intermediate or connecting
strip to be almost entirely above the water in common atmospheric air. The point
up to which the said strip will then be immersed in the water will designate the
specific gravity 1. The strip may consist of a thin piece of metal, preferably
having a sectional shape thus L or thus for giving it support, or it may
be formed of a tube of very thin metal or glass, the hollow part of such tube
communicating with the liquid and with the gas chamber. The said metal strip

page_text: is preferably 6 millimeters wide and about 0.25 millimeters thick, or, in case of
a tube, the material composing the same may be proportionately thin, so as to
give the strip a section of about 1.5 square millimeters and about 12 centimeters
length.
The upper globe should have an outer volume of say 115 cubic centimeters
which would correspond to a diameter of about 6 centimeters.
When the said receptacle contains a vacuum, the weight of the upper glass globe
is apparently increased by 115 × 0.0013 = 0.15 grammes; the apparatus there-
fore, in order to restore the equilibrium, will sink until the connecting strip will
have displaced 0.15 cubic centimeters of water.
Now, as the sectional area of the said strip is 0-015 square centimeters, the
apparatus will sink about 10 centimeters. The point up to which it will be-
immersed, designates say the specific gravity 0. If I now graduate or divide the
said strip between the two points of immersion (in common air, 1, and in vacuum, 0,)
say into 100 equal parts or so many millimeters for instance, I am enabled to read
off the specific gravity of any gas passing through the said receptacle, down to
0.01 and even 0.005 with great exactness. In hydrogen gas, for instance, (having
a specific gravity of 0.069) the connecting strip will thus sink to 7 millimeters
below 0 and in illuminating gas of 0.45 specific gravity it will sink to 45 millimeters
below 0, etc.
Thus it will be understood that for graduating the scale a vacuum (i.e. the
absolute zero-point) is not required, but that, instead, hydrogen may be employed
which may readily be obtained in a pure state, since it is well understood that by
means of any two fixed points (such as 1 (atmospheric air) and 0.07 (hydrogen)) the
size of the graduation is clearly designated.

page_text: of Gases and Vapors, and for Analyzing the same.
I, FRIEDRICH Lux, of Ludwigshafen-on-the-Rhine, in the Kingdom of Bavaria,
and German. Empire, Civil Engineer, do hereby declare the nature of my
invention for "IMPROVEMENTS IN APPARATUS FOR ASCERTAINING THE SPECIFIC
WEIGHT OF GASES AND VAPORS AND FOR ANALYZING THE SAME" and in what
manner the same is to be performed, to be particularly described and ascertained
in and by the following statement :—
This invention relates to apparatus for ascertaining or determining the specific
weight, or gravity of gases and vapors, and it may, in some cases, be employed
with advantage in ascertaining the pressure of such gases, or vapors, and for
analyzing the same.
Heretofore, the specific weight of vapours, or gases has been ascertained either
by means of simply weighing them, or by measuring the speed of their outflow (as
proposed by Bunsen, and Schilling), or by making use of the principle of communi-
cating tubes (as proposed by Recknagel).
]
The disadvantage of all these methods of determining the specific weight of such 1
gases and vapors is that they require a certain length of time for each trial, and do
not allow of examining a current of gases with regard to its specific weight, or its
pressure, in continued succession by simply reading the same from a scale, or
graduation. It is thus obvious that a method by which the said disadvantages
can be obviated will be of great value in ascertaining the specific gravity of
or vapors.
gases
The improved apparatus is based upon the principle according to which the
weight, or gravity, of a body in gas or vapor appears less than when in a vacuum
by the weight of the quantity, or volume, of the gas or vapor displaced by the
Baid body.
In the accompanying drawing
Figures 1, 2, 3, 4, 5 and 6 are views illustrating the construction of apparatus
according to this invention, and hereinafter described.
Figure 7 is an elevation illustrating a modification of the said invention.
A indicates a glass receptacle and B a stopper closing the same tightly.
2
2
The said receptacle is provided with inlets and outlets C C¹ for the gases or 3
vapours.
Within the said receptacle is arranged a body E of relatively large volume and
small weight say a hollow globe of thin glass.
This glass-globe E is connected with a body F floating in some suitable liquid,
and both bodies are connected by means of some material of small sectional area, 3
such as a thin glass-tube, a strip of metal, a wire, a hair, a thread or the like. In
case of a flexible material, such as hair, thread or thin wire being used for making
the connection, it will be necessary also to provide a pulley as in Figures 1 and 2,
said pulley being dispensed with when some rigid material is employed for the
purpose, as in Figures 3 and 4.
4

page_text: If, when the glass globe is arranged in a vacuum, gases or vapors be admitted
thereto, the said glass-globe will apparently become lighter, whereby the hydro-.
static equilibrium is affected, so that the body F, floating in the liquid, will, when
the arrangement shown in Figures 1 and 2 is employed, sink, because, in this case,
the glass-globe E acts as a counterweight (-); but when employing the arrange-
ment as shown in Figures 3 and 4 the said float F will rise, the glass-globe in this
instance acting as a direct weight (+) upon the float.
As the weight of gases is in inverse ratio to the pressure of the same, it is
obvious that an increase or a decrease of such pressure will cause the glass-globe
to apparently become lighter or heavier, respectively, and thus to indicate such
pressure.
Supposing that I designate the point indicated by the apparatus, when placed
in a vacuum, with 0, and the point indicated in an atmosphere of 15° Celsius and
760 millimeters mercury pressure, with 1, then the scale between 0 and 1 and also
beyond 1 may be divided at will.
As the devices described are enclosed within a glass or other transparent
receptacle so that they can be brought into contact with any desirable gases or
vapours of any specific weights or pressures, it will be understood that the specific
gravity or pressure of the said gases or vapours may be read off directly from the
scale.
The gases or vapours being allowed to pass continuously through the receptacle,
the indications may be read off at any moment, no further manipulation being
required for the purpose.
An apparatus particularly well adapted for ascertaining the specific gravity of
illuminating gas, is shown in Figures 5 and 6, and is constructed as follows, that is
to say
The glass-receptacle A is about 40 centimeters high and about 7 centimeters
wide and is closed by means of a closely fitting stopper B, and provided with
laterally arranged inlets and outlets C and C¹ for allowing the gas to be examined
to pass through the apparatus. This receptacle contains the measuring device, the
latter consisting of the glass globes E and F connected with each other by means
of an intermediate strip G, the measuring apparatus floating in distilled water,
petroleum, or any other suitable liquid.
The globes E and F are hollow, the former being filled with air and the latter
with water, mercury, or the like, in such a manner as to cause the intermediate or
connecting strip G to be almost entirely above the water in ordinary atmospheric
air. The point up to which the said strip will then be immersed in the liquid
will designate the specific gravity 1.
The said connecting strip may consist of a thin piece of metal, preferably having
a sectional shape thus or thus for giving it support, or it may be formed
of a tube of very thin metal or glass, the hollow part of such tube communicating
with the liquid and with the gas chamber. The said strip when made of metal is
preferably 6 millimeters wide and about 0-25 millimeters thick, or, when in the
form of a tube the material composing the same may be proportionately thin, so
as to give the strip a section of about 1-5 square millimeters and about 12 centi-
meters length.
The upper globe should occupy say 115 cubic centimeters, which would correspond
to a diameter of about 6 centimeters.
When the air is exhausted from the receptacle A so as to form a vacuum, the
weight of the upper glass-globe is (since a cubic centimeter of air weights
The
0.0013 grammes) apparently increased by 0.0013 × 115 = 0.15 grammes.
float F therefore, in order to restore the equilibrium, sinks, until the connecting
strip G has displaced 0-15 cubic centimeters of liquid: As the sectional area of
the said strip is 0.015 square centimeters, the said float will sink about 10 centi-
meters. The point up to which it is immersed, designates the specific gravity 0.
If I now graduate or divide the said strip between the two points of immer-
sion (in common air 1, and in vacuum, 0,) say into 100 equal parts, or so many

page_text: millimeters for instance, I shall be enabled to read off the specific gravity of any
gas passing through the receptacle A, down to 0.01 and even 0·005 with great
exactness. In hydrogen gas, for instance, (having a specific gravity of 0.069) the
connecting strip will thus sink to 7 millimeters below 0 and in illuminating gas
of 0.45 specific gravity it will sink to 45 millimeters below 0.
Thus it will be understood that for graduating the scale, a vacuum (i.e. the
absolute zero-point) is not required, but that hydrogen, which may be readily
obtained in a pure state, may be employed instead, since it is well understood that
by means of any two fixed points such as 1 (atmospheric air) and 0-07 (hydrogen)
the size of the graduation is clearly designated.
I may also utilize my said improved apparatus constructed and operating as
hereinbefore described, for analyzing gases, particularly illuminating gas, by
combining a number of my said apparatuses with suitable absorption apparatuses
interposed between, and connected with, each two of my improved apparatuses, for
which latter I have adopted the term "Bareometer" since its action is similar both
to that of a barometer and of an areometer. Heretofore the qualitative as well as
the quantitative analysis of mixtures of gases was usually made in the volumetric
manner by successively eliminating from a certain volume of gas, by means of
absorbents or otherwise, the component parts of the said volume one after another,
and measuring the remainders, the volume of the eliminated gas being seen every
time from the difference obtained.
Now the quantity of the divers component gaseous parts may be ascertained
equally well by the specific gravities of the original mixture and the remainders of
the gas, but hitherto this has been practically impossible for the reason that the
former methods of, and apparatus for, ascertaining or determining the specific
weights of gases do not allow of making a continued examination within closed
vessels, while my said improved apparatus may be readily employed for the said
purpose.
"
This application will be readily understood by referring to Figure 7 of the
drawing which shews the said "bareometer" when combined with the said inter-
posed absorption-vessels. In said figure A¹ A² A³ are three "bareometers
and B¹ B the interposed absorption-vessels connected therewith and containing
pieces of pumice-stone, coke, or the like, impregnated with some suitable absorbent
such as potash, chloride of copper, pyrogallic acid, or the like.
The gas to be analzed, enters the series of vessels through the vessel A¹ and leaves
the same through the vessel A³. The specific gravity of the original mixture is
determined within the bareometer A'. If the vessel B¹ contains potash the latter
will, as the gas passes through it, absorb the carbonic acid, the specific weight of
the gas now free from carbonic acid is determined in the bareometer A. Thus the
quantity of carbonic acid in the original gas can be readily ascertained from the
difference betwen the specific weights of the gases in the vessels A¹ and A. If
the gases in the two vessels are found to be the same, the absence of carbonic acid
in the gas is clearly indicated. The gas may next enter the vessel B' which
contains chloride of copper for absorbing the carbonic oxide in the gas, and its
specific weight is then determined again in the bareometer A³. This analysis may
be continued by adding another vessel B containing pyrogallic acid to absorb the
oxygen in the gas, or another such vessel containing incandescent peroxide of
copper to absorb the hydrogen, and so on as will be readily understood.
A mixture of gases composed of two known gases, or of one gas and atmospheric
air, can thus be analzed quantitatively by means of one bareometer while for each
additional gas one more apparatus is required. For instance :-Suppose a mixture
of known gases a and b having the specific weights S¹ and S respectively, the
specific weight of said mixture having been found to be S³, then the composition of
the mixture will be found from the following equation, viz
x S¹ + (1-x) S² = S³
E
11

page_text: The said improved apparatus, or bareometer, is preferably provided with two
thermometers (not shewn in the drawing) one of them being suitably arranged
within the liquid, and the other in the gas-space, in order to allow of readily
ascertaining the temperatures prevailing at any time within the said liquid and
gas-space, with a view to making any required corrections and reductions on a
basis of 0° Celsius and 760 millimeters mercury pressure.
Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed, I declare that what
I claim is
First. In apparatus for ascertaining in a direct manner the specific gravity, or
pressure, of gases and vapours, the combination, with a bulb or globe E, of a float F
floating in a suitable liquid within a closed vessel A and connected with the said
bulb E by means substantially as described, the said vessel A being provided with
gas-inlet and outlet apertures, as, and for the purpose, set forth.
Second. The combination, with two or more of the said apparatuses or
bareometers, constructed and operating substantially as herein described, of
suitable absorption apparatus interposed between each two of the said bareometers,
as, and for the purpose, specified.
HASELTINE, LAKE & Co.,
For the Applicant.