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 a fireless cooker, for, although cheap, they are very apt to rust from the confined moisture. Enamelware kettles are satisfactory.
EXTRA SOURCE OF HEAT
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.
Fig. 42.—Tightly fitting lid
COVERING PAD
A cushion, or pad, must be provided, to fill completely the space between the top of the packing material and the cover of the box after the kettle is in place. This should be made of some heavy goods, such as denim, and stuffed with cotton, crumpled paper, or excelsior. Hay may be used, but it will be found more or less odorous. Figure 43 shows the vertical cross-section of a home-made fireless cooker.
