After a while quite a wind sprang up, and as the sea roughened the professor decided to go down under the surface. The Porpoise sunk as the tanks filled and, in a little while, the submarine was in calm water, and was forging ahead at three-quarter speed.
It was three days after the adventure with the whale when, as the ship was going along at a good rate, that there seemed to be a gradual slacking in the progress.
"I wonder what Washington is slowing down for," said the professor rising from the dinner table at which all save the colored man had been sitting. "I told him to keep right on. He must have seen something ahead. I'll take a look."
The inventor went to the conning tower, where Washington was steering.
"What are you stopping for?" he asked.
"I'm not slowin' down," replied the colored man. "Guess another ob dem debil fishes has grabbed holt ob de ship. Dey suttinly am de most koslostrous conglomerations ob inconsequence dat I eber see."
"You must keep your big words for another time," remarked Mr. Henderson, who seemed worried. "Hurry to the engine-room and see if the machinery is all right. We certainly are slowing down, from some cause or other."
The Porpoise was now scarcely moving, though from the vibration it was evident that the engines were working almost at top speed. Washington came back and reported that the big screw was revolving properly and that all the machinery was working well.
"Then we're caught in something," said the professor. "Shut off the power, Washington, I don't want to strain things."
The ship was now scarcely making a foot a minute, and, a little later, when the colored man had turned off the engine, the submarine became stationary, merely undulating with the roll and heave of the ocean.