mike and give him some air another common form about today sion burning is a rapid combining about to jump with fuel without oxygen nothing can burn if we cut down the supply about to join the fire gets weaker and when the oxygen is used up the flame goes out by covering the fuel with water or chemicals that keep the air from getting in we can cut off the supply of oxygen and put a fire out but when the fire gets plenty of oxygen it will use all the fuel it can get the more air it gets the faster up fire burns so when we want to talk fires that will get the maximum energy out of the fuel we supply a lot of their free air air is forced up through the flaming bed of coals in the modern locomotive in many ocean going ships when extra power is needed the entire boiler room is filled with air under pressure causing a strong grip to rush through the fire one of the easiest things to ignite is gasoline if we pour a few drops of it on a lot of cut it will evaporate burning of gasoline and the best example of control is in the automobile engine but liquid gasoline alone won't run an automobile engine it has to be mixed with free air this mixing is done on the same principle used in the garden spray gun when we pump the gun our rush of their picks up tiny drops of liquid and forces them out the nozzle in a spray or miss in order to get a fine spray  the spring gun is small in the automobile engine this mixing of air and gasoline is done in the carburetor it begins in the tunnel through which the air sweeps at a speed sometimes as high as eight hundred miles per hour this whirlwind races past the mouth of a small tube and carries the droplets of gasoline into the intake manifold and onto the engine this funnel is called the  it controls the speed of the air air has to go faster to get through the small opening as the air goes faster and faster it breaks the gasoline into even smaller drops now now we let  more air and further thin out the mixture until we get the correct proportion for power and economy the up to date carburetor is a higher development there are closed chambers to regulate the fuel all the features that engineers are designed with great care to make sure of economical results but the principle is still the same the carburetor has but one purpose and that is to mix a little wrap of gasoline with the great big bubble up free air in a one cylinder engine made for laboratory experiments we can see through a quartz glass window the burning as it occurs like like  the development of these modern methods of mixing gasoline with air together with the improvements made in gasoline pump intake manifold and cylinder head design have resulted in increased mileage per gallon of gasoline let's prove it let's see just how much air is actually used in the modern automobile we'll take all the air that goes into the carburetor from this big balloon and the gasoline from this to the b here's a race that's worth watching a race to see how much gasoline we need while using enough to run our car one fourth of a mile less than three tablespoonfuls of gasoline to travel a quarter of a mile in fact one tablespoon full of gasoline is mixed with about three gallons of to make the fuel for the