A brief explanation of stoves is given in this chapter to help the woman with a new stove or with an old one which she does not understand so that she may manage it without wasting fuel and nervous energy. [Illustration: FIG. 1. Cross-section of cooking stove.] Cooking stoves (Fig. 1) were invented as a convenient means for holding pots and pans in close proximity to the fire. They include a device for regulating the supply of air to the burning fuel. =1. Air Supply for Fire.= A proper amount of air must be supplied to the fuel to produce a hot fire. A smoky or yellow flame indicates a lack of sufficient air to produce complete combustion of the fuel. Smoke is unburnt fuel. A smoky fire does not produce as much heat as one which burns with a blue or almost colorless flame. It is usually not the fault of the fuel, but the way it is being used that causes a smoky fire. =2. The Grate.= Cooking stoves may be constructed for burning either wood or coal. In both cases, the operation is similar, except that more air should be passing thru the stove while wood is being burnt. For burning coal, the grate should be less open in order to prevent the coal from falling thru. Some modern stoves are made with double grates. These may be turned so that the more open part of them is used for supporting the wood, and the less open part for coal. [Illustration: FIG. 1-_a_. Grate.] These grates are usually reversed by a stove shaker. (Fig. 1-_a_ shows a detailed drawing of a grate.) The housekeeper must understand how this is done in order to avoid reversing them when she shakes down the ashes. Two difficulties arise in reversing the grate when the stove is filled with fuel. The coal may be wasted by falling thru the part intended for wood, or pieces of fuel may fall between the parts so that they cannot be moved. When this happens, it is best to let the fire go out, take out the fuel, adjust the grates as they should be and rebuild the fire. =3. Drafts or Dampers.= There are from three to six dampers on a stove (Figs. 1 and 2), as follows: 1) The draft below the fire box, found on all stoves, is to let in air to the burning fire. 2) The draft above the fire box, not found on all stoves, when slightly opened, lets in air which completes the combustion of the gases arising from the top of the fire. When opened too wide, it checks the burning of the fire. 3) The oven damper, found on all cook stoves, is placed at the point where the flame naturally enters the stove pipe. When this damper is closed, the flame must go around the oven instead of directly up the chimney.