5/31 A part of the inner ear looks very much like a snail shell. How we Hear.~--Scratch with a pin upon one end of a long wooden pole. Have some one listen with the ear placed close against the other end of the pole. He will tell you that he hears the scratching of the pin very plainly. This is because the scratching jars the ear and especially the drum-head, which vibrates just as the head of a drum does when it is beaten with a drum-stick. |