"Mother, isn't it wonderful? Last week there were no leaves on the tree, but now the leaves and a nest and eggs in the nest." said Mary as she looked out the upstairs window. "How soon will there be little birds there? How long before the eggs hatch?"

"I don't know," said the mother. "Why don't you go to the library? They will have a book that will tell you more about it."

"They do have a book about eggs hatching," said Mary.

"Yes," said the mother, "and the library has books on almost everything."

"Where do they get all those books?" asked the child. "And who writes all of them?"

"The library is filled with books by generous people and by know…