As the young Scout leader spoke, Ensign Hargreaves burst into the engine room.
The engines were still whirring and buzzing, and the hull of the Peacemaker was quivering under their powerful stress.
"Have you developed every ounce of power they are capable of?" asked the naval officer.
"Yes, sir," responded Rob respectfully; "they can't do another revolution."
The officer looked anxious.
"In that case, we shall have to resort to my forlorn hope," he said.
"And what is that, sir?" asked Rob, his heart beating uncomfortably fast.
"Come forward and you shall see."
The ensign turned and swung out of the engine room, followed closely by two anxious boys, Rob having waited only to shut off the engines.
In the main cabin Mr. Barr, his face white and strained, sat on one of the leather divans.