Once more the engines were started. This time there was no hanging back on the part of the Porpoise. The big screw revolved, the water came in the shaft and was thrust out of the rear end, making a current that sent the craft ahead swiftly. The gigantic fish had been killed, and its body no longer obstructed progress.
"Now we'll rise to the surface and see how it feels to sail along that way for a while," said the professor as he started the pumps that emptied the tanks. In a little while the ship was floating on the waves.
It was now night, and the clouds overhead made it so dark that it was hard to see ten feet in advance. The professor did not want to use the searchlight for he did not care to have his presence discovered by curious persons. So he ran the ship at half speed.
"Where are we now?" asked Mark, who had entered the conning tower, where the professor was steering.
"Somewhere's off the coast of South Carolina," replied the inventor.
The next instant there was a sudden shock and jar. The ship quivered from stem to stern, and came to an abrupt stop.
"We've hit something!" exclaimed the professor, shutting down the engines with a jerk of the lever.