=21. Acetylene Stoves.= Stoves for the burning of acetylene are similar in construction to gas stoves. The acetylene furnishes a satisfactory and economical light, it is not an economical fuel when compared with kerosene, gas, wood or coal. For this reason, it is not much used. It requires two and three-tenths units of acetylene gas to equal one unit of natural gas for heating. CHAPTER III OIL STOVES [Illustration: FIG. 11. Parts of oil stove burner.] =22. Purpose of Oil Stoves.= Oil stoves are designed for the comfort of the woman who cannot have a gas or an electric stove. They consist of tank, feed pipe and burners (Figs. 11-_a_ and 11-_b_). As they are portable, they can be moved to a summer kitchen or sheltered back porch on hot summer days. Oil stoves are not fool-proof and should never be used by those who are afraid of them and who do not understand them. Manufacturers have done much to make accidents avoidable, and they send detailed instructions with each stove. These should be followed exactly. =23. Mechanical Parts of Kerosene Stove.= The kerosene oil stove consists of a tank of oil with a pipe leading to a hollow ring-like cup below the burner (_A_, Fig. 11). When the burner is lighted, the oil passes down this pipe into the ring, where it becomes heated and is vaporized. As the vapor rises, it is mixed with air and burns with a blue flame. The small holes in the chimney of the burner and at the base of the burner are to admit air. They must be kept open. [Illustration: FIG. 11-_a_. Large oil stove with oven.] If the burner is dirty or not properly adjusted, the right amount of air may not reach the vaporized oil to mix with it and the stove will burn with a yellow flame, making soot and smoke. =24. The Burner.= The burner consists of a chimney, a wick or ring of asbestos, a valve or a lever, and a ring-like cup at the base of the burner. There are three distinct types of burners known as long chimney, short chimney and wickless. The wickless stoves are equipped with a ring of asbestos which serves the purpose of a wick. [Illustration: FIG. 11-_b_. Oil stove without oven.] [Illustration: FIG. 12. Oil stove burner, showing fire close to utensil.] The burners on one oil stove are usually all alike. The burners on various makes differ. Those in which the flame comes nearest the kettle or cooking food produce the most heat for cooking (Fig. 12). Those with the blaze farther away from the food seem to be easier for the excitable woman to manage (Fig. 13). =25. The Chimney.= Kerosene stoves are furnished with metal chimneys. A device for mixing air with the burning fuel forms a part of short chimneys (_B_, Fig. 11). The chimney must set on the burner properly, or the stove will not burn with a blue flame. After lighting a burner, give the chimney a turn or two to make sure that it is in place. There is usually a groove into which it fits. [Illustration: FIG. 13. Burner for oil stove.]