This book contains the following story:
The Crow and the Pitcher
On a hot summer day a crow was desperate for a drink of water when he came upon a pitcher half full of water. The crow put his beak into the mouth of the pitcher but no matter how hard he tried he could not reach the water. In despair he threw a pebble into the pitcher and the water rose slightly nearer to the top. Then he threw another pebble, and another, until eventually the water rose high enough in the picther that the crows beak could reach it. The crow quenched his thirst and flew away. Moral: little by little does the trick.