The trick was that there was a statue by each pool. The statues were of a knight in armor, a bull, a bearded mage, a princess, a lion, an eagle, a crow, and a beautiful, armless, naked woman. By using the three yes/no questions from the Orb of Knowledge you can cut the choices in half each time. For example, the following would work:
So the right choice was the pool next to the eagle.