“Chink put it there?”
“Why should he do that?” returned Bob.
“That’s too much for me, Bob, unless he did it by mistake, same as he exploded the gas in that reserve tank.”
“I don’t know how the water got in the tank, Speake, and it may have been accident quite as much as design.”
Speake left Bob to his lonely vigil. The gleam of the little searchlight, reaching out ahead of the submarine, flung an odd picture on the periscope mirror. The edges of the mirror were shrouded in darkness, out of which jumped the smooth, oily billows. The waves flashed like gold in the pencil of light.
Bob, holding the Grampus to her course, looked into the periscope absently. He was thinking of the motor’s recent trouble, and of the chopstick lying by the gasoline tank, turning both over in his mind and wondering aimlessly.
Suddenly he lifted his head. An odd note was mixing itself with the croon of the motor and the whir of the ventilator fans. The noise was not caused by anything aboard the submarine; of that Bob was positive. It was like the thrashing of a large propeller, growing rapidly in volume as Bob listened.
Under water sounds are carried far. The noise Bob heard was caught by the submerged hulk of the Grampus and reëchoed as by a sounding board.
“Half speed, Dick,” he called through the engine-room tube.
As the pace slackened, Bob’s eyes again sought the periscope mirror. Abruptly, out of the gloom that walled in the glow of the searchlight, rushed a steamer, its blotted outline crossing directly the submarine’s course. There were lights along the steamer’s rail, but it was plain her lookouts were asleep or they would have seen the Grampus’ searchlight.