"I believe you're right!" exclaimed Mr. Henderson. "But this will never do. They must stop!"
Once more the big gun on the ship was fired and the shell came dangerously close. At the same time several other reports, less in volume were heard, and the water all about the submarine began to bubble as the missiles from the machine guns cut the waves.
"Maybe it's an English vessel sent to capture Mark and me because of that anarchist trouble at the hotel," Jack went on.
"Nonsense!" exclaimed the captain. "But whatever it is, we must stop it, or they will sink my ship. Wave your handkerchief, Jack."
The boy sprang to the top of the conning tower, in order to permit those on the vessel to see him more plainly, and vigorously shook the white rag. That it was observed was evident when some one on the steamer wig-wagged back a reply. In a few minutes a boat was seen to put off from the ship, and soon a little launch, in command of a lieutenant in uniform, drew up alongside the Porpoise.
"Who is captain of this craft?" asked the lieutenant as he came aboard.
"I am," replied Mr. Henderson. "What do you mean by firing on me?"
"I am Lieutenant Muchmore," said the other, saluting. "Captain Wackford, of the Sylph, in His Britannic Majesty's service, presents his compliments, and asks you to pardon the occurrence. You see we took you for a derelict and were trying to sink you."
"I thought perhaps war had broken out between some country and the United States since we left port," went on Mr. Henderson, "and that you were trying to make a capture."
"No, it was only that we thought you a waterlogged craft, and a danger to navigation," repeated the lieutenant. "But what sort of a ship have you?"