Such being the case, Ashman concluded that the time had arrived when he should also take a hand.

Ziffak and King Haffgo placed their backs against the face of the rocks, along which the ledge ran, so as to open a clear course for the archer. The latter fitted his arrow with great care and then straightening up drew back the string and slowly levelled, the missile at the head and breast of the American.

"Does that fool imagine I am going to keep still and let him practice on me?" the latter asked himself, an instant before discharging his rifle, whose bullet went straight through the dusky miscreant and sent him toppling off the side of the ledge as dead as dead could be.

Not only that, but the ball wounded the warrior directly behind him, causing him to utter a howl which rang with piercing force from side to side of the cavern of diamonds.

This prompt act caused something like a panic, Ziffak seemed the most terrified of any. Facing about, he flung his arms aloft and shouted to the rest to hurry away before the white man killed them all.

They lost no time in obeying, and it was noticeable that King Haffgo, being well at the rear, added his frenzied commands for his warriors to lose no time in leaving the fatal spot.

Ashman could have sent a succession of shots along the ridge, as the party scrambled away, which would have toppled the dusky barbarians off like so many ten-pins; but he had no desire to inflict needless slaughter, and, in answer to the appeal of the shrinking Ariel, he had promised her that, so far as he was concerned, her parent should receive no harm.

He therefore contented himself with watching them, until a bend in the ledge hid them from sight, with the exception of their heads, and they, too, soon disappeared; because the frightened warriors, glancing back, and seeing their peril, crouched low to escape the bullets which they seemed to expect would come whistling about their crowns.

As long as the natives kept at such a distance, they could do no harm to the defenders; for they were too far off to make use of their javelins, and the single archer left was not likely to attempt to bring his weapon into play.

Naturally, Ashman and Ariel, finding they were left to themselves for a time, fell to speculating upon what was likely to be the next move of their enemies. He believed they would make an attempt to bridge the chasm separating them, a task which, as will be seen, was comparatively easy of accomplishment.

But should such a structure be laid, it must be so strait that only one could pass at a time, and the American could pick them off as often as they presented themselves. There were now no firearms at the command of the Murhapas, unless some one recovered the weapon of Burkhardt, and even then, Ashman would feel little fear of harm from the savages.

Ariel thought her parent and his little company would simply keep guard at the entrance of the cavern, in order to intercept them, if they discovered some way of re-crossing the chasm and attempted to leave.

But both were wrong.

The young man was resolved that no march should be stolen upon him. It was impossible for the Murhapas to pass far enough around to leave the place, without being seen, provided he kept unremitting watch, which he felt competent to do for a number of hours to come.

If the siege was prolonged, he could take turns with Ariel, whose bright eyes were quicker of perception than his.

In the cavern of diamonds, there was no means of telling when it was day or night on the earth outside. Lit by the eternal fires of the volcano, it was always day; but he carried a watch, which told him that the night was far advanced, and that the bright sun would soon shine upon mountain, forest, and river again, though his heart sank at the faint prospect of it ever being his privilege to greet the orb again.

The incidents of the next hour mystified both Ashman and Ariel.

The first movement which attracted their notice, was Ziffak, who, rising to the upright posture, so that his immense shoulders were in plain sight, was seen picking his way along the ledge, until he reached the opening on the other side. Through this he passed and was seen no more.

It was useless to speculate as to the............