One day the princes' of Hastinapur were playing together and their ball fell into a well. Then a ring, too, fell into the well The princes peered into the well but didn't know how to get them out.
Acharya Drona, who was standing nearby saw all this and said , " It is a shame that princes like you are not able to do such a small thing ." He picked up a blade of grass and shot it at the ball in the well. The blade got stuck to the ball. Then he shot another blade, which stuck to the end of the first blade. In this way, he made a chain of grass blades, which reached the top of the well.
He then pulled out the ball with it. Then he shot an arrow at the ring in the well. The arrow sprung back, and brought the ring with it. The princes' were very happy .
Bhishma felt that Acharya Drona was skilled enough to teach the princes archery and warfare and later made him the princes' teacher.