Fireless cookers are adapted to a much wider range of cooking if they
are provided with an extra source of heat in the form of a soapstone,
brick, or an iron plate which is heated and placed underneath the
cooking kettle. This introduces a possible danger from fire, in case the
hot stove plate should come into direct contact with inflammable packing
material such as excelsior or paper. To avoid this danger, a metal
lining must be provided for the nest in which the cooking vessels and
stone are to be placed.
[Illustration: _Fig._ 42.--Tightly fitting lid]