"What can it be that makes that big noise?" the frightened mother bird thought as the mower passed close by.
Then the sound grew fainter as the mower went to the other side of the field. The little mother bird settled down happily in her nest.
But it was not long before the sound came back again, closer and louder than before.
"What shall I do?" thought the mother bird. "What shall I do?"
She might have flown away herself. But there were the three young birds not yet old enough to fly.
So she sat still while the terrible noise kept coming nearer.
All this time, Bobby was playing here and there with Rover. Suddenly, Bobby thought of something. He ran toward the mowing-machine, waving his hands and shouting.
"Stop, Father, stop!" he said.
The mower made such a loud noise that Father could not hear what Bobby was saying, but he could see his arms waving.
"Whoa, Prince! Whoa, Daisy!" he said, and the horses stopped.