IMPROVEMENTS IN SELF-ACTING COOKING APPARATUS
Year: 1873

page_text: PROVISIONAL SPECIFICATION left by Louis Bopp-du-Pont at the
Office of the Commissioners of Patents, with his Petition, on the
11th June 1873.
I, LOUIS BOPP-DU-PONT, of the Firm L. and L. Bopp-du-Pont
Brothers, of Boulevard de Strasbourg, No. 23, at Paris, do hereby
declare the nature of the said Invention for "IMPROVEMENTS IN SELF-ACTING
COOKING APPARATUS," to be as follows:-
Several apparatus have already been contrived for the purpose of
keeping food warm during the time of its removal from the place where
it is cooked to the one where it is consumed, but these apparatus are
deficient by having but little cohesion between their constitutive and
isolating parts, which renders them inconvenient for use, and occasions
a great loss of time.
The system of thermostatic apparatus or cooking tin which I have
devised, avoids these defects by its very homogeneous construction, in
which each part fulfils the purpose it was designed for so as to render
the employment of the apparatus as simple and useful as possible, and
make it suitable for a great variety of purposes.

page_text: The apparatus consists of an interior saucepan or vessel containing tho
food commencing to boil, and of an outer vessel or envelope intended to
hermetically enclose the first one, and completely isolate it from the air,
and the arrangement which I have effected unites the conditions which
answer best for the exigencies of the army, navy, and other uses, both
domestic and general.
food commencing to boil, and of an outer vessel or envelope intended to
hermetically enclose the first one, and completely isolate it from the air,
and the arrangement which I have effected unites the conditions which
answer best for the exigencies of the army, navy, and other uses, both
domestic and general.
Easy and prompt management, little deterioration or wear in the
employment, and great convenience are some of the advantages of my
apparatus,
I proceed to describe several arrangements of my cooking can or
apparatus in detail. The apparatus I prefer for travellers, workmen,
fishermen, and other such purposes is composed of a cooking saucepan,
and an envelopping vessel to keep in the heat.
The saucepan proper is made of zinc or tin, and is provided with a
cover which can itself serve as a receiver for coffee or other liquids by
providing it with a bottom and a screw plug. The saucepan may be of
any convenient form, and its dimensions will be in relation to the uses
for which it is intended; for the army the oblong form appears the most
suitable as it can be easily carried upon the knapsack of the soldier.
The cover of the saucepan has a rim provided with a ring of felted
caoutchouc in order to form a hermetic joint. The handle is arranged
so as to fall upon the cover and fit in very neatly in the fitting of the
envelope, so as not to interfere with the cover of the envelope itself.
Ear pieces to which the handle is fastened are fitted by pressure in the
isolating material, which covers the interior of the envelope. The cover
can also serve as a plate when the food is consumed.
The envelope formed of the same shape as the saucepan is
strengthened by thin stamped hoops curved and soldered, and placed at
the top and bottom, and all its exterior surface is covered with a stony
and siliceous glaze, while its inner surface is covered with a thick felt
fabric coated with blackened silicate of potassium, and stony oxide of
zinc. The upper level of the felted fabric is covered with a band of zinc
curved and soldered to the side of the envelope. The felt fabric is
besides magnetized, which renders it unattackable by the action of the
fire or damp. I also place in the apparatus sheets of straw pasteboard
coated with the same substance as the receiver, and fixed to the zinc
with white of ceruse, which renders them adherent and impermeable,

page_text: The whole is fixed by means of glue with alkali or spirit (such as
resinous gum lac heated by steam and dissolved in alkali) serving to
homogenefy and solidify the felt so as to avoid its deterioration. The
envelope is closed by a special cover having a handle furnished in the
interior with magnetized felt, and shaped so as to form upon the edges
of the felt a hermetic and at the same time an elastic closing. The
envelope is also provided with a strap with hooks of copper or other
metal, which facilitate the handling. Claws serve in addition to fix the
envelope upon the knapsack of the soldier. For horsemen and persons
in analogous positions the apparatus will be formed in a long oval shape,
and can have at the bottom a strap which will permit it to be fixed to
the body, so as to avoid a too great shaking; or at need the apparatus
can be attached to the saddle by means of buttons, which adapt them-
selves to rings.
The arrangement of my thermostatic apparatus which I prefer for the
use of pedlars, and for people who distribute warm drinks, such as tea,
coffee, chocolate, soup, and milk, in public roads or workshops, is as
follows: The inner vessel or saucepan is provided with a cock passing
through the outer vessel or envelope, through which the liquid can be
drawn, and the envelope is in the shape of a column with a hinged top.
In order to be able to remove at will one or other of the drinks or food
away from the apparatus, I have arranged a form of apparatus in which
the outer vessel or envelope is constructed with two compartments, into
each of which an inner vessel or saucepan with a cover arranged as
before-described fits, or one cover will serve for both compartments, each
section of the cover in this case closing with one or two oblong hooks or
rings, fastening upon a nut on the envelope.
In a pocket arrangement of my thermostatic apparatus the envelope.
is replaced by a case prepared of my special fabric, which closes with a
button and a cord or caoutchouc ribbon.
The method of employing this cooking can differs in no way from the
other apparatus contrived for the same purpose. The saucepan, after
having been about three quarters filled with water, is placed upon the
fire for about half an hour, the meat or other material to be cooked is
then put in, and the boiling continued during another half hour. The
saucepan is then removed from the fire and placed immediately into the

page_text: outer vessel or envelope, which is closed immediately. The cooking
thus continues without fire for several hours.
The applications of my system of cooking can are very numerous; for
the army it offers immense advantages, which will be at once perceived;
it will also serve as a ball shield in consequence of the great thickness 5
of the felted materials, it will be of use for ambulances, for the navy, for
domestic, and agricultural, and general purposes, and it effects in all
these conditions a great economy of time and fuel.