CERTAIN IMPROVEMENTS IN LAMPS FOR BURNING MINERAL OILS
Year: 1865

page_text: LETTERS PATENT to Peter Armand le Comte de Fontaine Moreau, of
the General Patent Offices, 10, Rue de la Fidélité, Paris, in the
Empire of France, and 4, South Street, Finsbury, London, Patent Agent,
for the Invention of "CERTAIN IMPROVEMENTS IN LAMPS FOR BURNING
MINERAL OILS."-A communication from Monsieur Louis Theodore
Letourneau of Paris in the Emping of Thrones
Fontaine Moreau at the Office of the Commissioners of Patents, with his
Petition and Declaration, on the 22nd May 1865, pursuant to the 9th
Section of the Patent Law Amendment Act, 1852.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, PETER
ARMAND LE COMTE DE FONTAINE MOREAU, of the General Patent Offices, 10,
Rue de la Fidélité, Paris, in the Empire of France, and 4, South Street,
Finsbury, London, Patent Agent, send greeting.
WHEREAS I am in possession of an Invention for "CERTAIN IMPROVE-
MENTS IN LAMPS FOR BURNING MINERAL OILS," and have petitioned Her Majesty
to grant unto me, my executors, administrators, and assigns, Her Royal
Letters Patent for the same, and have made solemn Declaration that it is
a communication from Monsieur Louis Theodore Letourneau, of Paris, in the
Empire of France.
NOW KNOW YE, that I, the said Peter Armand le Comte de Fontaine
Moreau, do hereby declare that the following Complete Specification under my
band and seal fully describes and ascertains the nature of the said Invention,
and in what manner the same is to be performed, in and by the following

page_text: statement, reference being had to the Drawing hereto annexed, and to the
figures and letters marked thereon, that is to say:-
The Invention relates to certain modifications or improvements in lamps
having their level invariable, such as the carcel, moderator, and other similar
lamps, by which improvements they are rendered capable of burning petroleum
and other mineral oils.
These improvements consist, first, in the mode of rendering the piston and
stuffing box impervious.
Secondly, in the mode of diverting the overflow of the oil back into the
recipient.
Thirdly, in the employment of a metallic wire gauze to prevent explosion
when oils of low density are burned, and to prevent also the introduction of
foreign bodies into the reservoir.
Fourthly, in fitting the moderator of the lamp into a low socket to suppress
friction.
Fifthly, in the application of a striking or alarum apparatus for giving
notice that the oil requires to be pumped up.
Sixthly, in the employment of a float set at the mouth of the oil reservoir
to shew when it is full.
And in order to have the Invention more easily understood, reference can
be had to the annexed Drawing and to the letters of reference marked on the
Figures therein contained.
Petroleum being of a less density and of a greater fluidity than the vegetable
oils used for lamps and being capable besides of rapidly dissolving several
organic substances, especially fatty bodies, it is necessary to render impervious
and of the utmost perfection the fittings of lamps for burning petroleum. In
order therefore to render the leather employed for the piston impervious to
the dissolving agency of the petroleum, I dip the piston in a solution of
carbonate of soda, by which the grease contained in the leather is transformed
iuto a soapy substance, which is itself changed into insoluble margarat of lead
by the leather being immersed in acetate of lead; and to fill up the pores of
the leather which have remained wide open the piston is dipped in a luke-
warm gelatine and glycerine solution, which becomes insoluble in a tannic acid
and alcohol bath. However, as this process will probably render the piston
rather stiff, I use preferably a solution composed, first, of one hundred parts
of alcohol at ninety-five degrees; secondly, three hundred parts of sulphuric
ether at sixty-six degrees; thirdly, forty parts of cold drawn castor oil; and
fourthly, six parts of pyroxyle. This solution is left to settle for twenty days
and then filtered. The piston after being first pierced is left for twenty-four

page_text: hours in the solution, and this treatment renders it tight and impervious. It
is then dried in a stove, after which the petroleum can have no effect on it
whatever. As the use of petroleum serves to increase rather than lessen the
friction of the different parts of the lamp, I have improved the moderator so
as to overcome nearly the whole of the friction of the spindle or rod within
the tube. I give to the iron or steel spindle or rod a cylindrical form, having
a flatwise surface commencing at the top, which increases in size down to its
base, so as to form a very sharp triangular plane, having its top at the upper
part and its base resting on the bottom of the cylinder. The spindle works
very freely in nearly the whole length of the tube, and passes at the top of the
latter into a cylindrical part having a similar diameter to its own and being
about five-twelfths of an inch high. It is in this kind of ring that, on account
of the flatwise form of the rod, that the oil is made to ascend to the upper
part of the lamp. The sliding of the moderator tubo in a tube having a
larger diameter which conducts the oil up to the burner is made tight by
means of a stuffing box provided with compressed felt washers which are not
subject to the adhering and shrinking to which leather is liable. These
washers are compressed in a cylindrical chamber having externally on the
whole of its elevation a thin thread. They project out at the lower parts of
the elevation of the chamber, to which they are held by means of a per-
forated cap which screws on the chamber. The opening of the washers is
lessened or increased according to the way the cap is turned, and the friction
of the washers against the tube of the moderator is thus increased or lessened.
For the same reason that the piston is made very soft or flexible the spiral
spring which serves to draw it down should be much weaker than in the
ordinary lamps. To obtain the cooling during its descent to the reservoir of
the small quantity of oil brought to the wick by the pressure, and not required
for the combustion, it is caused to flow inside an annular space formed by the
two concentric tubes within which the wick is moved. By this means the oil
is cooled by the current of cold air which ascends through the tube to fill up
the vacuum continually produced by the combustion of the wick within the
chimney (shewn at A, Figure III., in the annexed Drawing). For that
purpose I prepare on the tube forming the inside of the annular space con-
taining the wick a ring of holes, at suitable distances apart, and at about three-
fourths of an inch below the upper orifice where the combustion of the wick
takes place. The overflow of oil passes through these holes into a second
very narrow annular space of about half a line wide. This space is formed
on one side by the internal tube concentric to the wick, and on the other side
by a third tube. This last tube is soldered at its upper end to the other tube

page_text: above the ring of holes, and at its lower end to the base of the same. The
space so enclosed communicates with the reservoir by means of a tube having
a diameter nearly capillary and descending as far as the level of the reservoir,
which is separated from the other part by a metallic wire gauze, by which
impurities are kept from the reservoir and explosions prevented. By the
means herein-before described the oil is brought back to the reservoir
without being heated, that is to say, at the ordinary temperature. The
burner is so arranged that it only remains to regulate the flame to obtain a
white, fixed, and odorless light. For this purpose I use the ordinary right-
angle elbowed chimney, and as narrow as possible. The chimney holder is
regulated so as to cause the elbow of the glass to reach about one-fourth of
an inch above the level of the burner. When the glass is in its proper
position, as above described, the flame will be white and steady, and without
smell. The impossibility of ascertaining the precise moment that it is
necessary to pump up the oil before its indication by the lowering of the
flame is an inconvenience in the moderator lamp consuming ordinary
petroleum oils; the wick carbonises during the time required to reach the
burner, it smokes and emits an unpleasant smell. I obviate these defects by
the herein-after described apparatus, which can be applied also to the ordinary
moderator lamp.
This apparatus is represented by D, D, Figure 2, and is composed of a
small bell fixed between the two pillars supporting the burner or set on one
of them, and a lever and hammer similar to those employed for such purposes.
Three notches are cut on the upper part of the rack at some distance apart.
When the rack is descending the first notch meets with the lever of the
hammer and draws it down until the catch compelling it to rise suddenly
causes it to strike the bell, the second and third notches being reached in a
similar manner by the lever of the hammer the bell is struck as before
described. It will thus be seen that before the rack has completed its
descending movement three separate warnings are given, with an interval of
some minutes between them, before the complete lowering of the light.
To avoid the frequent overflowing of the oil on the exterior of the lamp
when it is carelessly filled up, I employ a float which is composed of a stem
fixed by its base to a substance lighter than oil. This stem egresses through a
hole prepared in the ring forming the base of the burner, so that the float will
rise with the level of the oil and indicate when the reservoir is full.
The improvements constituting the Invention herein-before described can
be applied to lamps already constructed, having an invariable level and
burning petroleum and other mineral oils.

page_text: And having now described the nature of the Invention communicated to
me and the manner of carrying the same into effect, I wish it to be under-
stood that I do not confine myself to the precise details herein laid down, so
long as the peculiar character of the Invention be retained; but what I
claim is,
First, the means of rendering the piston and stuffing box impervious, as
herein-before described, reference being had to B, Figure 1, of the Drawing.
Secondly, the arrangements for conveying the overflow of oil back to the
recipient, as herein-before described and illustrated in Figures 1 and 3 of the
Drawing.
Thirdly, the employment of the wire gauze in the manner and for the
purposes herein-before described.
Fourthly, the application of a socket of small elevation for receiving the
moderator so as to lessen the friction, as herein-before described and shewn
at c, Figure 5.
Fifthly, the construction and application to moderator lamps of the alarum,
as herein-before described and represented by D, D, Figure 2.
Sixthly, the application to lamps of the float, berein-before described, for
showing when the reservoir is full, reference being bad to F, Figure 4, of the
Drawing annexed hereto.
In witness whereof, I, the said Peter Armand le Comte de Fontaine
Moreau, have hereunto set my hand and seal, this Nineteenth day
of May, in the year of our Lord One thousand eight hundred and
sixty-five.
Witness,
HY. GILBEE,
10, Rue de la Fidélité,
Paris,
19th May 1865.
P. DE FONTAINEMOREAU. (L.S.)