Captain Ross and Mr. Brown hurried below deck again, but presently came up, and the seaman said:
"We can't find anything wrong below—no leak or anything. We may have hit a big, submerged log or piece of a wreck. Start the motor again, Bunker, and we'll see if that's all right."
The gasolene engine was not damaged, but something else was wrong. As soon as the machinery started there was a trembling and throbbing throughout the whole boat, but she did not move ahead.
"I see what the matter is!" said Captain Ross. "The propeller is broken. It hit something."
"Oh, can't we go to Christmas Tree Cove?" asked Sue.
"We'll get there somehow," answered Captain Ross. "But the propeller is surely broken."
And so it proved. The propeller, you know, is something like an electric fan. It whirls around underwater and pushes the boat ahead. The propeller on the Fairy had struck a floating log and had been broken, as they found out later.
"If we can't go by means of the engine we can sail," remarked Captain Ross, when it was found that the boat would not move an inch, no matter how fast the motor whirled around. "Hoist the sail, Bunker. We'll get Bunny Brown and his sister Sue to Christmas Tree Cove yet! Hoist the sail!"
"Oh, it's lots of fun to sail!" cried Bunny.
"I like it better than motoring!" added Sue, who was no longer yelling.