George Frank Barnhart, age 12, of Tulsa,  la.,  or his question:

  Where does the horizon end?

The earth is a globe, a fat round ball. Wherever you are on a curved surface. The ground slopes gently away from you in all directions. The horizon is as far as you can see. It forms a line where earth and sky seem to meet.

Look down a long straight road bordered with telephone poles. The poles sink lower and lower into the distance. Only their tops peek over the horizon. Now drive down the road. The horizon moves with you. The faster you go, the faster it recedes. It always keeps its distance and you can never catch up with it.

You can travel clear around the earth and never catch up with the horizon. For, wherever you stand, you stand on a hump. You can see so far and no farther. The limit of vision from where you stand is the horizon.