ABSTRACT
225If you stick your hand out of a moving train, you will feel the force of the air. As the train approaches the station, gradually coming to a halt, the air ceases to press on your hand. The train is at a stop, and you lean out of the car window, smelling, in turns, the aroma of wild flowers, the stench of overheated steam, and of the locomotive soot. The air moves and brings you one smell or another. You cannot feel the pressure of this air on your hand; it exists below the threshold of your perception.
