“That is well; you did well. It is of immense advantage to a man, whatever his position in life, that he should be able to write shorthand with facility. Especially useful is it in commerce. I know that, having had some experience of commercial life.”

At this point in the conversation Nigel was startled by what was to him an absolutely new sensation, namely a shaking or trembling of the whole cavern, accompanied by faint rumbling sounds as if in deeper caverns below him.

He glanced quickly at his host and at the negro, but to his surprise these remarkable men seemed not to be aware of the shaking, although it was severe enough to cause some of the furniture to rattle. Observing his look of surprise, Moses remarked, with a benignant though capacious smile, “Mountain’s got de mulligrumps pritty bad jist now.”

“We are pretty well accustomed to that,” said the host, observing that Nigel turned to him for an explanation. “No doubt you are aware that this region is celebrated for earthquakes and volcanoes, so much so that the inhabitants pay little attention to them unless they become unusually violent. This island of Krakatoa is itself the fragment of an extinct volcano; but the term ‘extinct’ is scarcely applicable to volcanoes, for it is well-known that many which were for centuries supposed to be extinct have awakened to sudden and violent activity—‘quiescent’ might be a more appropriate term.”

“Yes,” said Moses, ceasing to masticate for purposes of speech; “dem ’stinkt volcanoes hab got an okard habit ob unstinkin’ dereselves hereabouts when you don’ ’spect it of ’em. Go on, massa. I ax yer pard’n for ’truptin’.”

The hermit’s peculiar good-natured little smile played for a moment on his massive features, and then faded away as he continued—

“Perhaps you may have heard that this is the very heart of the district that has long been recognised as the greatest focus of volcanic activity on the globe?”

“I have heard something of the sort,” answered Nigel, “but I confess that my knowledge is limited and my mind hazy on the subject.”

“I doubt it not,” returned his friend, “for geographical and scientific training in primary schools anywhere is not what it might be. The island of Java, with an area about equal to that of England, contains no fewer than forty-nine great volcanic mountains, some of which rise to 12,000 feet above the sea-level. Many of these mountains are at the present time active.” (“Yes, much too active,” muttered the negro), “and more than half of them have been seen in eruption since Java was occupied by Europeans. Hot springs, mud-volcanoes, and vapour-vents abound all over the island, whilst earthquakes are by no means uncommon. There is a distinct line in the chain of these mountains which seems to point to a great fissure in the earth’s crust, caused by the subterranean fires. This tremendous crack or fissure crosses the Straits of Sunda, and in consequence we find a number of these vents—as volcanic mountains may be styled—in the Island of Sumatra, which you saw to the nor’ard as you came along. But there is supposed to be another great crack in the earth’s crust—indicated by several volcanic mountains—which crosses the other fissure almost at right angles, and at the exact point where these two lines intersect stands this island of Krakatoa.

“I emphasise the fact,” continued the hermit after a pause, “first, because, although this has been a quiescent volcano since the year 1680, and people have come to regard it as extinct, there are indications now which lead me to believe that its energy is reviving; and, second, because this focus where fissures cross each other—this Krakatoa Island—is in reality part of the crater of an older and much larger volcanic mountain, which must have been literally blown away in prehistoric times, and of which Krakatoa and the neighbouring islets of Varlaten, Polish Hat, Lang Island, and the rest, are but the remnants of the great crater ring. If these rumblings and minor earthquakes, which I have noticed of late—and the latest of which you have just experienced—are the precursors of another explosion, my home here may be rendered untenable.”