The screw was just beginning to turn when a dull explosion came to the ears of all on board.
A rush of sand, mud, steam and fire followed and stones beat a steady tattoo on the steel plates of the Holland XI.
Some of the mud and stones became entangled in the screw of the submarine craft and in their hurry to get away from the vicinity the boat was run into a forest of seaweed and marine brushwood.
The whole bottom of the sea was moving and they realized that an earthquake was at hand.
They were caught in the very midst of the awful disturbance and it was a question whether or not they would get out of it alive.
CHAPTER XXIX.
THE RESCUE OF JEAN FEVRE.
It was a moment of extreme peril and nobody realized it more than did Captain Oscar Pelham.
Should the Holland XI. become fast between the rocks and mud now pouring forth on all sides the submarine craft would be doomed.
"Turn her and run at full speed!" he shouted. "To port, quick!"