. To pack the container with paper, crush single sheets of
newspaper between the hands and pack a layer at least four inches deep
over the bottom of the outside container, pounding it in with a heavy
stick of wood.

Place the inside container for the cooking kettle or the lining for the
inside of the nest in the centre of this layer, and pack more crushed
paper about it as solidly as possible. The method of packing with paper
is shown in Figure 40. If other material is used it should be packed in
a similar way.

Where an extra source of heat is to be used, it is much safer to use
some non-inflammable material such as asbestos or mineral wool. A cheap
substitute and one which is easily obtained are the small cinders sifted
from coal ashes, preferably those from soft coal. However, the cinders
from hard coal burned in the kitchen range will do. If a fire-proof
packing material is not used, a heavy pad of asbestos should be placed
at the bottom of the metal lining, and a sheet or two of this paper
should be placed between the lining of the nest and the packing
material. Whatever is used should come to the top of the inside
container, and the box should be filled to within about four inches of
the top.

[Illustration: _Fig._ 40.--Fireless cooker, showing method of packing
with paper]

THE INSIDE CONTAINER

The inside container for the cooking kettle or the lining for the nest
in which it is to be placed should be cylindrical in shape, should be
deep enough to hold the cooking kettle and stone, if one is used, and
should fit as snugly as possible to the cooking kettle, but at the same
time should allow the latter to be moved in and out freely. For this
purpose a galvanized iron or other metal bucket may be used, or, better
still, a tinsmith may make a lining of galvanized iron or zinc which can
be provided with a rim to cover the packing material, as shown in Figure
41. In case no hot stone or plate is to be used, the lining may be made
of strong cardboard.

[Illustration: _Fig._ 41.--Metal lining with rim]

THE KETTLE

The kettle to be used for cooking should be durable and free from seams
or crevices which are hard to clean. It should have perpendicular sides,
and the cover should be as flat as possible and be provided with a deep
lid fitting well down into the kettle, in order to retain the steam. A
kettle holding about six quarts is a convenient size for general use.
Tinned iron kettles should not be used in