The Crow and the Pitcher - Aesop fables

A crow, half-dead with thirst, came upon a pitcher which had once been full of water. 

But when the Crow put his beak into the pitcher, he found that there was only a little water left in it. 

Try as he would, he could not reach far enough down to get a drink.

Then a thought came to him. 

He took a pebble and dropped it into the pitcher. 

Then he took another pebble and dropped it into the pitcher. 

Before long, he could see the water rising higher and higher. 

After casting a few more pebbles, he was able to get a drink.

*   *   *

Little by little does the trick.