Alcohol and Gasoline Lamps
109. Classification of Lamps. Since the principle of operation is the same for most alcohol and gasoline lamps, they will be considered together.
Fig. 53. Gasoline or alcohol lamp.
These lamps may be divided into two classes—gravity lamps and pneumatic, or pressure, lamps.
110. Gravity Lamps. Gravity lamps have the tank elevated above the burner so that the force of gravity brings the fluid to the burner. It is usually a little to one side of the burner so that it cannot become heated by it. A pipe from the tank leads downward and either over the chimney or under the burner, where it will be heated by the flame of the lamp. When heated, it changes the gasoline or the alcohol to gas. The pipe carries the gas on to a point where it is mixed with air before it flows into the burner (Fig. 53).
111. Lighting the Gravity Lamp. In order to light these lamps, the generator must first be heated so as to make the gas. After this has once been done, the heat of the lamp keeps the generator hot. As soon as the gas is formed, light the lamp.
These lamps are furnished with mantles. The flame is blue and, consequently, gives out very little light, but much heat. The mantle covering the flame is heated to glowing white heat and gives off much light of a white color.
112. Pressure Lamps. Pressure lamps (Figs. 54 and 55) have a strong tank which holds air and fuel, whether alcohol or gasoline. Air is pumped into the tank so that it presses on the fuel with force enough to push the fuel up the pipe leading from the bottom of the tank to the generator. The air cannot get into the pipe so long as there is fuel which is heavier than air in the tank, because the pipe which leads to the burner starts from the bottom of the tank.
