[Illustration: Glaciers on the Coast of Norway]
"Yes, the rivers, the ice rivers or glaciers, the wind, the frost, heat and cold, all grind masses of rock into bowlders, pebbles, and sand."
"The rock has been ground so long I should think there would be nothing left but soil," said Frank.
"You saw the limestone down by the spring?" asked Uncle Robert.
"Yes," the children said together.
"That limestone was once soft mud spread out upon the bottom of the ocean in shallow water."
"How do you know that is so, uncle?" questioned Frank.
[Illustration: Fossil fish.]
"There are many proofs, but the best proof is that in the limestone are found shells of animals that live in the sea," said Uncle Robert.
"Fossils," said Mrs. Leonard.