“Island,” said Gregory, gruffly, “volcanic, and the coral has risen up round it, and kept it from being washed away.”
“But could an island like this have been washed away?” said Mark.
“To be sure it could, my boy,” said the captain. “From what I have seen a great deal of it is loose scoria. You saw plenty of big stones lying about?”
“Yes,” replied Mark, “but they were huge stones. Some of them must weigh half a ton.”
Mark knew that half a ton meant ten hundredweight; but his comparison was a shot at a venture, for he had no idea how big, or rather how small, a rock is which weighs half a ton.
“I don’t think the sea would make much of a rock weighing half a ton, Mark,” said the captain, smiling. “Why, in one of our great storms it would move that almost as easily as if it were a pebble. Mr Gregory is quite right. Volcanic islands have before now been formed, and been in eruption for a long time, and then been slowly swept away by the action of the sea.”
“How long to sundown, sir?” said Mr Gregory.
“Half an hour,” said the captain, after a glance at the slowly descending orb.
“And then it will be dark directly. What do you say, sir, give it up, land and set up camp, or keep on?”
“Keep on, Gregory,” said the captain, quietly. “There is a headland away yonder. Once we get round that we may see home. Tired, my lads?”