The words had hardly left his lips when there came a jar and a bump that shook the submarine in her every frame and rivet.
The boys were thrown from their feet and hurled about the cabin. At the same instant the engines stopped and the submarine began to back, but slowly, like a stricken animal.
"We've rammed something!"
"We're sinking!"
These and a hundred other exclamations came from the alarmed boys.
Mr. Barr poked his head down into the cabin.
"Are you all right below?" he asked.
"Yes; but what has happened?"
"Have we been badly damaged?"
"Are we sinking?"