Robert Simon, Age 10, Of Allentown., Pa.v for his question:

How thick is the earth's crust?

Our solid globe is enfolded in a rocky layer of minerals which we aall the earth's crust. The center of the solid globe is almost 2000 miles below our feet ¬the surface crust is about a hundredth part of this distance. Yet so far., man has not pierced the earth's crust to the denser layers of minerals that lie beneath it.

The crustal is not even in thickness. Under the lofty alps, it is estimated to be 40 miles thick, and under certain plains, the rocky crust may be only 10 miles in thickness. The crustal layer below parts of the pacific ocean is 20 to 30 miles thick. On the world wide average., the thickness of the earth's crust is estimated.