The encyclopaedia of practical cookery

Several applications of Heat to cookery are described under the names of special culinary processes, to which reference should be made; also to Fuel, Stoves, and numerous other headings associated with the same subject, including Air, Refrigeration, and Ventilation. These, one and all, depend upon certain principles which are under the control of the cook. Heat can be measured (see Thermometers) and conveyed at will wherever it may be required. Its power can be regulated to a nicety, and the laws by which its actions are governed are well known ; for instance, a black uneven surface absorbs Heat, and a bright polished surface repels it ; hence, in a black kettle water heats much quicker than in a bright one. Again, there are some materials which are bad conductors of Heat, such as woolly materials containing stationary air amongst their fibres. As these will not allow Heat to pass either in or out, they are excellent when wrapped round for keeping the body warm or ice from melting. Soot is a non-conductor, and so are many other things of a similar character. Wood is a bad conductor of Heat also, hence wooden handles are much used, and manufacturers endeavour to keep the metallic handles of teapots cool by intercepting the handle top and bottom with a wooden or ivory disc; but as these discs are kept in their places by iron screws passing through them from metal to metal, the metallic continuity is kept up, and the handle gets very neatly, if not quite, as hot as it would without them. See Heat-Conductors. HEAT-CONDUCTORS.— Since the abolition of oldfashioned spits from all but large kitchens, and the [illustration: Fig. 944. Heat-Conductors for Cooking (H. T. Tallack).] introduction of closed stoves, cooks have experienced some difficulty in cooking joints or birds through to the centre without burning the outsides. The iron spit [illustration: Fig. 945. Sirloin Transfixed.] thrust through the centre conducted heat into the very heart of that which was roasting, and thus produced far more satisfactory results than can be obtained by any For details respecting Culinary Processes, Utensils, Heat-Conductors — continued. other system. The power that metal has of conducting heat is well known, and can be experienced by putting a poker in the fire, when in time the handle will become too hot to hold, or much hotter than its distance from [illustration: Fig. 946. Leg of Mutton, Lamb, or Pork Transfixed] the fire would otherwise warrant. An ingenious inventor has taken advantage of this knowledge to manufacture certain instruments (see Fig. 944), which, being based upon strictly scientific principles, can be made to take [illustration: Fig. 947. Slice of Fish Transfixed.] the place of the spit in its heat-conducting properties. They consist of enlarged ends, or collectors, ball-shaped as A, cup-shaped for the sake of giving more space as b, and a small metal plate for boiling as c. The two former, A and B, are black and carbonised to induce absorption of dry heat, whilst the plate of c is plain metal. The rods are all made of the best conducting metal known, and their modes of application are almost [illustration: Fig. 949. Heat-Conducting Cake-tin.] interminable. Figs. 945 and 946 show the manner of transfixing joints for roasting or baking, and Fig. 947 shows a slice of fish, such as of cod or salmon, transfixed for boiling; while [illustration: Fig. 948.] shows yet another Sauces, dec., referred to, see under their special heads.