“Stop them,” howled Mr. Robinson, who had just dashed on deck, holding a limp right arm; but no man moved. Only a loud splash broke the silence, and the stern was empty. “Man overboard. Lower a boat. Stop the yacht, you cursed fool,” snarled Mr. Robinson to the Captain, and then he rushed to the stern. Dimly in the failing light he thought he could see two heads in the water, but it was a couple of minutes before a boat was lowered, and in that couple of minutes he heard the roar of an engine coming nearer. Then the engine ceased, and he saw the outline of a motor-boat. “That boat may have picked ’em up, sir,” said the Captain, as Mr. Robinson ran down the gangway into the waiting cutter. “Give way all,” came the second officer’s curt order. “With a will, boys.” The motor-boat, still m

