The effect of the in-rushing water was to cool the upper surface of the boiling lava and convert it into a thick hard solid crust at the mouth of the great vent.  In this condition the volcano resembled a boiler with all points of egress closed and the safety-valve shut down!  Oceans of molten lava creating expansive gases below; no outlet possible underneath, and the neck of the bottle corked with tons of solid rock!  One of two things must happen in such circumstances:  the cork must go or the bottle must burst!  Both events happened on that terrible night.  All night long the corks were going, and at last—­Krakatoa burst!

In the hurly-burly of confusion, smoke, and noise, no eye could note the precise moment when the island was shattered, but there were on the morning of the 27th four supreme explosions, which rang loud and high above the horrible average din.  These occurred—­according to the careful investigations made, at the instance of the Dutch Indian Government, by the eminent geologist, Mr. R.D.M.  Verbeek—­at the hours of 5.30, 6.44, 10.2, and 10.52 in the morning.  Of these the third, about 10, was by far the worst for violence and for the wide-spread devastation which it produced.

At each of these explosions a tremendous sea-wave was created by the volcano, which swept like a watery ring from Krakatoa as a centre to the surrounding shores.  It was at the second of these explosions—­that of 6.44—­that the fall of the mighty cliff took place which was seen by the hermit and his friends as they fled from the island, and, on the crest of the resulting wave, were carried along they scarce knew whither.

As the previous wave—­that of 5.30—­had given the brig a tremendous heave upwards, the captain, on hearing the second, ran down below for a moment to tell Kathleen there would soon be another wave, but that she need fear no danger.

“The brig is deep and has a good hold o’ the water,” he said, “so the wave is sure to slip under her without damage.  I wish I could hope it would do as little damage when it reaches the shore.”

As he spoke a strange and violent crash was heard overhead, quite different from volcanic explosions, like the falling of some heavy body on the deck.

“One o’ the yards down!” muttered the captain as he ran to the cabin door.  “Hallo, what’s that, Mr. Moor?”

“Canoe just come aboard, sir.”

“A canoe?”

“Yes, sir.  Crew, three men and a monkey.  All insensible—­hallo!”

The “hallo!” with which the second mate finished his remark was so unlike his wonted tone, and so full of genuine surprise, that the captain ran forward with unusual haste, and found a canoe smashed to pieces against the foremast, and the mate held a lantern close to the face of one of the men while the crew were examining the others.

A single glance told the captain that the mud-bespattered figure that lay before him as if dead was none other than his own son!  The great wave had caught the frail craft on its crest, and, sweeping it along with lightning speed for a short distance, had hurled it on the deck of the Sunshine with such violence as to completely stun the whole crew.  Even Spinkie lay in a melancholy little heap in the lee scuppers.