The advantages of electric cooking are obvious. The heat is directly conducted to each utensil, and a minimum amount is lost in radiation. The degree of heat is perfectly under control, and the manipulation is nothing more than the turning of a knob. When the apparatus is installed, it is adjusted to the voltage, so that no further regulation is necessary. There are no waste products, and no matches to light or throw away. If the wiring is properly done, there is no danger from fire. The one present disadvantage is the cost. Each piece of apparatus is expensive. The cost of running must depend upon the cost of electricity in the neighborhood, and the number of watts per hour used by each piece of apparatus. The larger the utensil, the more watts consumed. The disk stove in Fig. 22 uses 250 watts; a disk of 6 inches diameter, 475 watts; of 8 inches, 650 watts. Some pieces of apparatus are arranged for three different heats, with a different number of watts for each heat. With one disk stove 10 inches in diameter, 3 heats are possible, with 250, 500, and 1000 watts respectively. [Illustration: FIG. 22.——A disk electric stove. _Courtesy of Landers, Frary and Clark._] =Oven thermometers.=——A thermometer is furnished set in the door of many ranges. While these are guides after one has learned to use the oven, they are not really accurate by scale. For exact work in testing oven temperature, a hole must be bored in the side of the oven, and a chemical thermometer inserted, protected by asbestos and metal. Simple tests for oven temperature will be found in Chapter XI. EXERCISES 1. Why is the question of the cost and kind of fuel important? 2. What is the difference between hard and soft coal? Between red and white ash? 3. Why are certain fuels in more common use than others? 4. Explain the advantage of gas over coal. Over kerosene. 5. What are the advantages of electricity as a source of heat? 6. Explain the way in which electricity is measured. 7. Read the gas meter at home and estimate the amount and cost per day. (The ordinary burner consumes about two cubic feet per hour.) 8. Obtain the prices of the fuels used in the neighborhood and work out a comparison of the cost of fuel for preparing a meal.[8] 9. What are the methods of conserving heat in cooking apparatus? 10. Explain the structure and management of a coal stove. 11. Explain the principles involved in making a fire. 12. The structure and management of a gas stove. 13. Why does gas in a burner sometimes “pull back”? 14. State the requirements in a perfect example of cooking apparatus. CHAPTER IV FOOD PREPARATION, THE PRINCIPLES AND TECHNIQUE