=84. Kerosene Heaters.= Kerosene heating stoves have burners like those used on kerosene cook stoves. (See Chapter III.) Surrounding, or about, the burner is a jacketed air space. Here air is heated and rises to the upper part of the room while fresh air from the lower part of the room is drawn thru the jacket. Some heat is also given off by radiation. Fig. 43 shows a picture of an oil heater. [Illustration: FIG. 43. Oil heater.] The burners of these stoves should be cared for the same way as the ones on cooking stoves. The stove should be kept polished and free from dust. This prevents it from rusting. Wipe off any kerosene which may accumulate on the outside, for it makes an unpleasant odor. Take care in moving kerosene stoves not to jar the chimney or other parts of the burner out of place; otherwise the stove will smoke. When the stove is lighted, turn the burner quite low. The flame will become higher as the parts of the stove become heated. [Illustration: FIG. 44. Electric heater.] =85. Electric Heaters.= The electric heaters (Fig. 44) are composed of one or more coils of wire thru which the electric current flows with difficulty. This heats the coils so hot that they glow. A reflector throws the heat out into the room. The coil and reflector are attached to a pedestal. They are desirable for use in rooms which are not quite warm enough. Care must be taken to avoid getting an electric shock from electric heaters, as from any other electrical appliances. If the stove seems to be out of order, have it put in order before using. Take care not to touch a water pipe or gas pipe at the same time when touching the heater in the bathroom, as there is a possibility of getting a shock. =86. Acetylene Heaters.= Acetylene heaters are similar to the Bunsen burner and asbestos-back gas heaters. They are provided also with copper side reflectors. They are used only in localities where gas or electricity cannot be had. QUESTIONS FOR PART II 1. What are the essentials in heating a house with a hot-air furnace? 2. How does the "pipeless" furnace differ from the other types? 3. Explain the circulation of water thru a hot-water heating system. 4. What is the purpose of the expansion tank? Where should it be located? 5. Describe a steam-heating system. 6. What care should be taken in managing a steam-heating system? 7. What precautions should be taken when using an electric heater? PART III LIGHTING DEVICES CHAPTER XII ELECTRIC LIGHTS =87. Kinds of Electric Lamps in Use.= The electric lamps on the market now are either tungsten (also called Mazda) or metallized carbon (called gem carbon) lamps. Of all lighting appliances, electric lamps and systems are most easily cared for. If properly selected, they make an excellent light from the standpoint of hygiene. It is important for every one to know enough about lighting to be able to select proper kinds and sizes of lamps.