One of the most useful household utensils which has recently come into prominence is what is usually known as the fireless cooker. This name is more or less misleading, as many people get the idea that no heat whatever is necessary for its use. Some even think that food put into it absolutely cold will come out smoking hot, an obvious impossibility. Misunderstanding is so prevalent, however, that in this lecture it has seemed best to give the name of cooking box to this device.
The cooking box is by no means a new invention, for the principle on which it is built, namely, protecting a hot article so it will keep hot for a long time, has been applied for uncounted years. For generations Norwegian peasants, among whom the whole family goes to the fields to work, have been in the habit of using so-called hay boxes in which their dinners cook during their absence. It is said that in Germany working people sometimes start their soup on the stove and then leave it between feather beds to finish cooking. Cooks in Maine lumber camps bury their bean pots in ‘bean holes’ in hot embers and ashes and leave them to bake during the day. The ‘clam bakes,’ so popular along our Atlantic coast, represent the same kind of cooking under other conditions.
All these people are employing exactly the same principle that is behind the construction and use of the most perfect of the cooking boxes now on the market. The principle may be stated in a very few words, namely, the protection or insulation of a hot material by a suitable packing or covering so that the heat will be retained in amount sufficient to cook the article, instead of being quickly lost. In the ordinary oven, or on the top of the ordinary stove, food is cooked by means of heat which is continuously applied. If the cooking box is to be used, the food is heated on an ordinary stove, to the point at which the necessary cooking process begins; then it is put into a box so constructed that the heat in the food can not escape from it except very slowly, and the cooking continues without the use of more heat. Of course in the oven or on the stove top, the food reaches a higher temperature or is kept at a high temperature longer than in the cooking box. The latter, therefore, can not be so well used for the kinds of cooking in which prolonged high heat is needed as for those in which long slow cooking is desirable….
Since the power of holding food for a long time near the temperature at which it is put into the cooking box is the important feature of this device, evidently the best cooking box, other things being equal, will be the one from which heat is given off least rapidly.
The cooking box consists in its essentials of a receptacle for the hot food, and a container for this receptacle which is packed or otherwise insulated with suitable material, so that the heat will not escape, but the food will remain hot and continue to cook. Every woman who wraps up a hot soapstone or a bottle of hot water in a flannel, so that it may keep hot for a long time applies the principle of the fireless cooker.
