“You will soon see a change come over it,” said the hermit, as the party gazed in silent admiration at the weird scene.

He had scarcely spoken, when the middle of the lake became intensely black and scored with dark streaks.  This, though not quite obvious at first from the point where they stood, was caused by the slow formation of a great chasm in the centre of the seething lake of mud.  The lake was sinking into its own throat.  The blackness increased.  Then a dull sullen roar was heard, and next moment the entire lake upheaved, not violently, but in a slow, majestic manner some hundreds of feet into the air, whence it fell back into its basin with an awful roar which reverberated and echoed from the rocky walls of the caldron like the singing of an angry sea.  An immense volume of steam—­the motive power which had blown up the lake—­was at the same time liberated and dissipated in the air.

The wave-circles died away on the margin of the lake, and the placid, cloud-reflecting surface was restored until the geyser had gathered fresh force for another upheaval.

“Amazing!” exclaimed Nigel, who had gazed with feelings of awe at this curious exhibition of the tremendous internal forces with which the Creator has endowed the earth.

“Vonderful!” exclaimed the professor, whose astonishment was such, that his eyebrows rose high above the rim of his huge blue binoculars.

Moses, to whom such an exhibition of the powers of nature was familiar, was, we are sorry to say, not much impressed, if impressed at all!  Indeed he scarcely noticed it, but watched, with intense teeth-and-gum disclosing satisfaction, the faces of two of the native porters who had never seen anything of the kind before, and whose terrified expressions suggested the probability of a precipitate flight when their trembling limbs became fit to resume duty.

“Will it come again soon?” asked Nigel, turning to Van der Kemp.

“Every fifteen or twenty minutes it goes through that process all day and every day,” replied the hermit.

“But, if I may joodge from zee stones ant scoriae around,” said the professor, “zee volcano is not alvays so peaceful as it is joost now.”

“You are right.  About once in every three years, and sometimes oftener, the crops of coffee, bananas, rice, etc., in this region are quite destroyed by sulphur-rain, which covers everything for miles around the crater.”

“Hah! it vould be too hote a place zis for us, if zat vas to happin joost now,” remarked Verkimier with a smile.

“It cannot be far off the time now, I should think,” said Yan der Kemp.

All this talk Moses translated, and embellished, to the native porters with the solemn sincerity of a true and thorough-paced hypocrite.  He had scarcely finished, and was watching with immense delight the changeful aspect of their whitey-green faces, when another volcanic fit came on, and the deep-toned roar of the coming explosion was heard.  It was so awesome that the countenance even of Van der Kemp became graver than usual.  As for the two native porters, they gazed and trembled.  Nigel and the professor also gazed with lively expectation.  Moses—­we grieve to record it—­hugged himself internally, and gloated over the two porters.