After the meal Bob went up on deck with Glennie, and Dick did the steering from the top of the conning tower. The Gulf of Paria was a great watery plain, over which the waters of the Orinoco spread themselves before mingling with the sea.
The ensign, feeling that he was disliked, drew back into his shell and bore himself with a chilly reserve. Along toward three o’clock Bob relieved Dick and sent him below to sleep. Directly after supper Dick would have to relieve Gaines and stand his trick at the motor, and it was necessary for him to get a little rest. Carl would also have to relieve Clackett, and, in order to be fit for his duties, the Dutch boy had turned in immediately after dinner. He was sleeping on the floor of the periscope room, and Dick curled up on the locker.
The afternoon saw the Grampus well across the gulf, and by five o’clock she changed her course to south by east, leaving the densely wooded hills of Trinidad far behind with the coast of Venezuela in plain view to starboard.
Ah Sin, having been duly instructed as to his duties, prepared the supper on the electric stove, and served it. Speake relieved Bob at the steering gear, and when Dick went below to take Gaines’ place at the motor, Bob sprawled out on the locker to catch his own forty winks. A stiff sea was running, and the Grampus was submerged to a depth that merely left the periscope ball clear of the combers.
As the darkness deepened, Speake had Carl put the turbines at work, throwing out sufficient water ballast to lift the conning-tower lunettes clear of the waves. The electric projector was then turned on, and a ray of light shot through the forward lunette and marked the submarine’s path through the tumbling sea.
For some hours everything went well. Then abruptly the motor began to sputter and misfire, lessening the speed of the boat and throwing her—now that she was riding higher and with the top of the conning tower awash—more at the mercy of the waves.
Loose furniture began to slam around the periscope room. Bob was thrown from the locker, and sat up, wondering what had gone wrong with the motor.
“What’s the matter down there, Dick?” he called through the motor-room tube.
“I’m a Feejee if I know,” Dick answered. “You’d better come down and take a look.”
Bob was soon at his chum’s side. His keenly trained ear was usually able to locate any ordinary trouble, but this time he was puzzled. The ignition was all right, and the supply pipe from the tank was clear. Nevertheless, the motor sputtered and jabbered with a wheezy but unsuccessful attempt to do its full duty. The platinum, in the blade or spring of the commutator, will, in rare cases, get loose and cause misfiring, but that was not the cause of the present trouble. Another rare cause, resulting in similar symptoms, lay in the loosening of the carbon pole in the cell of a battery. But, just now, the batteries were not at fault.