IMPROVE- MENTS IN PHOTOMETERS OR PHOTO-PHLOGOMETERS FOR MEASURING THE INTENSITY OF THE LIGHTING POWER OF GAS IN ACCORDANCE WITH THE SIZE OF THE FLAME.”
Year: 1875

page_text: LETTERS PATENT to Victor Bablon, Manufacturer, of the City of
Paris, in the Republic of France, for the Invention of "IMPROVE-
MENTS IN PHOTOMETERS OR PHOTO-PHLOGOMETERS FOR MEASURING THE
INTENSITY OF THE LIGHTING POWER OF GAS IN ACCORDANCE WITH THE SIZE
OF THE FLAME.”
PROVISIONAL SPECIFICATION left by the said Victor Bablon at the
Office of the Commissioners of Patents, with his Petition, on the
21st May 1875.
I, VICTOR BABLON, Manufacturer, of the City of Paris, in the
• Republic of France, do hereby declare the nature of the said Invention
of "IMPROVEMENTS IN PHOTOMETERS OR PHOTO-PHLOGOMETERS FOR MEASURING THE
INTENSITY OF THE LIGHTING POWER OF GAS IN ACCORDANCE WITH THE SIZE OF THE
FLAME," to be as follows:-
The object of the present Invention is to establish the flow of a volume
of gas always rigorously equal to itself at all times, no matter what the

page_text: density of the gas. Such a flow being established the simple measure
of the dimensions of the flame then suffices to indicate the lighting
power of the gas. I obtain the flow of this constant volume not by aid
of regulators, but by means of a capacity whence the gas is always
expelled at an equal speed.
rotary motion.
2. In a gas meter bell suspended by a cord to the barrel or wheel-
work of a clock mechanism, and descending with a speed rendered 1
constant by this mechanism.
3. And specially in a bell whose speed of immersion and consequently
of expulsion is regulated in the following manner:-This bell is enclosed
in a closed reservoir which only communicates with the atmosphere by
a straight and narrow orifice in such wise that as the bell descends 1
and drives the gas it contains it draws in an equal quantity of air
above it.
The speed of entry of the air may thus serve as measure of the speed
of exit of the gas, and as the orifice of admission of air is of invariable
size a similar degree of rarefaction of the air above the bell will always 2
indicate a like speed of descent of the bell.
A manometer indicates the depression produced above the bell, and a
tap placed on the exit tube of the gas admits by opening it more or less
of leading the manometer always to exactly the same point, and thus
producing the flow of a volume of gas always rigorously equal to 2
itself.

page_text: WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twenty-first day of May, in the year
of our Lord One thousand eight hundred and seventy-five, in the thirty-
eighth year of Her reign, did, for Herself, Her heirs and successors,
give and grant. unto me, the said Victor Bablon, Her special licence,
that I, the said Victor Bablon, my executors, administrators, and
assigns, or such others as I, the said Victor Bablon, my executors,
administrators, and assigns, should at any time agree with, and no others,
from time to time and at all times thereafter 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 PHOTO-
METERS OR PHOTO-PHLOGOMETERS FOR MEASURING THE INTENSITY OF THE LIGHTING
POWER OF GAS IN ACCORDANCE WITH THE SIZE OF THE FLAME," upon the con-
dition (amongst others) that I, the said Victor Bablon, my executors
or administrators, by an instrument in writing under my, or their, or
one of their hands and seals, should particularly 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 I, the said Victor Bablon, do hereby declare
the nature of my said Invention, and in what manner the same is to
be performed, to be particularly described and ascertained in and by
the following statement and accompanying Drawings:-
It is well understood that when the lighting power of a flame pro-
duced from lighting gas increases or diminishes the height of the flame
diminishes or increases in like manner, and many attempts have been
made to discover the lighting power in these variations of height. With
this view a current of gas has been established as regular as was practi-
cable, and by means of regulators the height of the flame obtained has
been measured by the combustion of this current. But this mode of
proceeding allowed the cause of irregularity to remain, the density of
the gas and consequently its co-efficient flow constantly changing. The
height of the flame suffers variations from this effect alone, which may
wrongly be attributed to variations of lighting power. And to obtain
with such apparatus true indications it is necessary to measure simul-
taneously both the height of the flame and the volume of gas consumed,

page_text: and these two quantities known the amount of lighting power is deduced
therefrom. There is therefore in this system a complication in the
observation and complication of the apparatus, since it necessitates a
regulator, an index, and chronometer.
My Invention consists not only in its detail of construction, but also
in establishing a flow of gas in a constant and rigorously regular
manner by means of a capacity from whence the gas is expelled by an
external dynamical action. The result of an arrangement similar to this
is that no matter what the density of the gas is its absolute volume of
flow in a given time remains constant.
Suppressing the risks of variation of volume it only remains to
measure the height of the flame to obtain by this sole and unique
measure the intensity of the lighting power of this flame. The
variations in the height of the flame may result from the greater or less.
richness of the lighting matter as I have described, but also in the
richness in oxygen of the air supply. This air impoverishing in oxygen
the flame elongates without varying in lighting power; it is thereforc
necessary that the apparatus I am about to explain should consist if
required of various dispositions to check this impoverishing of the air
which feeds the flame.
In order to obtain a constant flow of a single volume of gas I operate
according to the different methods here following:-
First. A clock gas meter c (see Fig. 1), or even the movable side of
a kind of organ blower forming a dry meter is charged with a weight
and suspended to a cord rolled round a drum Y worked by clockwork.
The movement of this barrel is rendered uniform in time by any suitable
mechanism in such wise that the variations of resistance offered to the
descent of the meter c are thus absorbed by the regulator of the clock-
work, and the descent always remains perfectly regular, and knowing
the section of the gas meter the volume of gas expelled in a given time
is known, such volume resting constant. B is the arrival tube and D
the flow tube of the gas.
Second. Instead of wet or dry meters I can employ as expelling
capacity the fly itself of a gas meter. In this case I unite the axis of
the fly to the shaft of the barrel moved uniformly by clockwork. This
arrangement has the advantage of giving continuous indications.
Third. I again specify that the preceding mechanism may be destitute

page_text: of any special motor, and use as motor the fly of the meter, which is
animated by the gas which traverses it under its own pressure. The
clockwork thus becomes the simple intermediary between the fly of the
meter and the dynamical regulator absorbing the variations of resistance.
I again obtain uniformity of motion of the fly expeller in coupling the
axis of this fly to the axis of the fly of a second meter, which would
traverse a perfectly regular current of air.
'
Fourth. Besides the preceding arrangements I have shown by Fig. 2
an apparatus which has the advantage of not requiring mechanical
apparatus. A closed capacity A. contains water or other liquid half its
height in which the bell meter C plunges, under which are two tubes, one
B for the arrival of the gas, the other D for its exit to the burner d.
Above the capacity A. are two tubes, one E furnished with a' tap, and the
other H supplied with a diaphragm / pierced with an invariable orifice,
a sealed glass tube V, in which the shaft T lodges, which serves as guide
to the bell C, and which at the same time shows the quantity of gas
contained under this bell at any moment, and lastly, a manometer I
for showing the depression existing at A above the bell. At the side of
the burner is a slide index with rack L moved by hand by aid of the
pinion and button M, and which by the indexes m and n take the height
of the flame and report it on the scale N. The bell is charged with a
suitable weight P.
Finally, the lid of the apparatus is pierced in the direction where the
shaft T passes through it with a crown of holes tabutting in the tube V
to allow the air to enter there and make its exit freely.
The working of the apparatus and its mode of graduation are as
follow:-The bell having been filled with gas by the tube B, the tap B¹
is closed, as well as the tap E, which during the filling of the bell
remains open for the exit of air. The tap D' is then opened and the
burner & is lighted. Supposing, for instance, Paris gas is employed, the
tap D¹ is turned until the extreme point of the flame reaches the centre
of the scale N, and the exact height occupied by the water in the mano-
meter I is observed. The return of air at h by an invariable orifice and
its speed of entry depending on the speed of exhaustion resulting from
the descent of the bell, the result is that at a like depression of the
manometer I a like speed of descent of the bell will always correspond.
In other words every time that the manometer is at a previously deter-
mined and same fixed point the volume of gas delivered and burnt at d

page_text: will always be the same no matter what the density of the gas. It only
remains to introduce successively under the bell gases of various lighting
powers and previously known to accomplish the graduation of the
scale N. At each of these experiments the tap D¹ is turned so as to
lead the manometer to the fixed and henceforth invariable point, and |
by causing the index m to ascend or descend the corresponding point to
these various lighting powers will be noticed on the scale N. The
intervals between these points can then be subdivided by interpolation.
The weight to be given to the bell and the section of the orifices d and h
are not fixed or determined, but when once established are invariable.
To prevent oxydation of the orifices d and h they are made of rings of
platinum. The diaphragm is surmounted by a capacity sufficiently
large and filled with cotton (uncompressed), in which the exhausted air
iş freed from dust.
•
In order that the pressure due to the weight of the bell O should 1
remain invariable it is necessary that the weight itself should be
unchangeable, but it is not so, and when the bell descends its immersed
sides lose their weight. I remedy this defect of loss of weight by
reducing the section of the bell in proportion as it descends in such wise
that a less weight acting on a less section ultimately gives place to a 2
uniform pressure.
Another modification that I introduce in the apparatus is that the
bell O instead of being enclosed in a closed vessel may be placed in an
uncovered recipient, then above or below this recipient is a second
recipient, containing a bell connected with the boll C to draw it along in 2
its movements. This latter bell contains air, which escapes by a pipe
arranged under this bell, and with invariable aperture. A manometer
indicates the pressure existing under this bell, and it again occurs that
by always leading the manometer to the same pressure that a constant
delivery of gas is obtained.
Before any experiment the apparatus should be purged of the gas it
may previously contain. For this purpose a tap F branched on the
tube D, being open, the gas is allowed to circulate in the apparatus
until completely expelled. A small burner fed by the tap F and kept
constantly burning will fulfil the same object.
In lieu of a bolted lid the capacity A may be closed by a rimmed lid
plunging in the liquid contained in this capacity..
3
3

page_text: I have said that it was in manœuvring the tap D' until the mano-
meter I is led to a point previously determined that a constant delivery
of gas is effected through the burner d, and in order to prevent any
difficulty in this manoeuvring I establish the automatic delivery by
means of the disposition shewn by Fig. 3.
In the course of the tube D, between the bell C and the burner d, I
place a regulator composed of a capacity K, in which a bell o can move
with double compartments, one o, the other Q, which has for section the
same as that of the valve S, which follows the bell in its movements.
The result of this is that the gas contained in Q does not exercise any
ascensional action on the bell, its action boing equipoised by that of the
valve S. The compartment o is in communication with the atmosphere
by the tube R.
The body of the regulator K is hermetically closed, and the capacity J
communicates with the upper capacity A (Fig. 2) by the tube X, the
said capacity being above the bell C. In explaining the working of the
regulator I suppose that the fixed point on the scale of the manometer I
corresponds to a depression of 6 centimeters of water. The bello is of
´such a weight that it is raised by this exhaustion of 6 centimeters of
water exercised beneath it by the tube X. The apparatus then acts.
After having expelled and stored the gas as described in the bell C the
tap B' is closed and the tap D¹ is opened wide. The gas escaping by the
burner d, the bell C descends, a partial vacuum occurs, above which
reaching 6 centimeters of water the bell o is raised and the valve places
itself in the desired position so that the delivery of the gas exactly cor-
responds with the depression of 6 centimeters of water. I have there-
fore automatically established a constant delivery of gas, no matter what
is otherwise its density. It may be conceived that the apparatus may
be used for other purposes, and in all cases where it is required to
momentarily establish a rigorously constant current as a volume of any
gas, no matter what its density and the section of the final exit
orifice.
The apparatus shown by Fig. 2, besides its special object of indicating
the lighting power of gas by the height of the flame, will instantly show
the density of gas. In this latter mode of use the tap D' is completely
opened, and the orifice d is the sole obstacle to the exit of the gas. This
exit tends to be just as rapid as the coefficient of flow is increased or its

page_text: density less, and the depressions indicated by the manometer I will then
be so much more considerable. The mode of graduation will be made
on the manometer I with the exit of the gas at d without lighting it, so
that nothing happens to change the proper state of the gas.
The apparatus enumerated' above can be equally employed with the
modifications resulting from'this application.
Finally, I consider as my Invention the different mechanical com-
binations based on the considerations above exemplified, and notably
those represented by the accompanying Drawings, whose object is to
'measure the lighting power of gas in accordance with the measure of 1
the flame, and which can also be employed to measure the density of
this gas.
. The forms, dimensions; and materials of construction of the con-
stituent parts are variable in relation to the applications of the photo-
phlogometrical apparatus.
In witness whereof, I, the said Victor Bablon, have hereunto set
my hand and seal, this Sixteenth day of November, in the year of
our Lord One thousand eight hundred and seventy-five.