Theresa Lalonde, age 10, of Clinton, New York, for her question:

How does the sound of the ocean yet into a seashell?

Inside this seashell there are rooms and compartments with curved and shiny rooms. The graceful little residence was created by a smallish animal who belongs to the sea. He extracted dissolved minerals from the water to build his shell    and his durable home survived after its owner died. The tossing tide washed it up on a beach. Some¬body found it and kept it to admire. Maybe it changed hands and several persons had a chance to admire it.

At least one person tested it to hear the sound of the distant sea. If you hold the wide open end of a coiled seashell to your ear, you hear a sound that certainly sounds like ocean waves. But this is not really so. Those inner compartments are cunningly shaped to catch and echo the slightest sound vibrations. They even catch and amplify the sound of your pulsing blood stream. What you hear when you put your ear to a seashell is not the waves, but the echoing beat of your own heart.