"It's a subterranean eruption!" exclaimed the captain. "Look—look yonder!"
Where he pointed, from the midst of the curling waves, a great black patch of what seemed to be mud rose above the surface.
Round it were thick columns of smoke, which instantly shut it out from view.
The wind chopped round, and a fierce gust came, laden with steam and smoke, from the north.
The yacht heeled over till her copper sheeting gleamed above the water-line.
Gasping for breath, for a fearful stench accompanied the smoke, which enveloped them, all on board could do nothing but hold on to whatever was handiest.
A rushing, roaring sound filled their ears as the Dart dashed onward, throwing the boiling water in showers of spray over her bows.
The men forward were forced to stagger aft.
It looked as if the Dart was doomed!