Lryce Blair., age l0, of Edmonton Alta.,. Canada; for his questions

How did the sea begin?

Geologists say that our ocean water was once steam and vapor trapped deep within the rocks of the earth. The surface of the young planet was hot enough to boil any water that fell upon it. There were fierce volcanoes, and much of the steamy vapor was forced up from below. It formed dense clouds, and for ages a suffocating blanket of clouds above the earth grew thicker.

This steamy chapter of the earth's history began to end when the surface rocks became cooler than boiling water. Rain from the dense clouds remained on the earth and began to collect in basins and hollows. In perhaps l,000 million years the oceans were partly filled. More water was added through the ages as more steamy vapor escaped from the earth's crust.