Even the bows and arrows had disappeared; and it was evident that the Warlattas had resumed warlike operations with a success resulting in the almost complete extermination of the tribe. Morton endeavoured to explain to them that their enemies were dead, but it was doubtful whether the old men comprehended him. An immediate incursion into the inner cave was determined on, and, provided with candles, the party soon found themselves at the opening. The sand had worked in and somewhat blocked up the space, but this was soon sufficiently removed to enable them to wriggle underneath like snakes. Half a dozen candles served to brilliantly light up the inner chamber, and there, with startling distinctness, shone out the white triangle over the sacrificial stone. Brown started the stone rocking, and immediately the shrill, half-human screams echoed through the cave, much to Billy's discomfiture. No examination could detect the trick that caused the sound, nor could the presence of the stone be accounted for except as a most singular freak of nature.
"I have it," said Morton at last; "the stone was part of the rock and has been cut away underneath. It must have been an awful job, but that is how it was done."
"And about the squeaking machinery?"
"That's more than we can find out without shifting the stone, and that's a job I am not on for unless we stop here a month or two and chip it in pieces."
"A charge of dynamite would shift it; and next time I go exploring I'll carry some," replied Brown.
"What do you think the thing was made for?" inquired Charlie.
"Well, I've just had an inspiration," said Brown. "You know amongst some nations it is a matter of religious belief almost that you must make your enemy howl when you have got him down. Now, perhaps some of the poor devils who were cut up on this stone declined to sing out, or fainted, or for some reason did not furnish amusement enough—the stone was set rocking to fill out the programme. What do you think?"
"I think it most likely, and is an instance of devilish cruelty on a level with their other proceedings."
"I suppose poor Stuart searched this place so thoroughly that we need not expect to find anything fresh," said Charlie. "But we may as well have a look. Billy, you have got sharp eyes, just use them."
While these two were investigating the walls and floor, Morton and Brown took a careful copy of the hieroglyphics and a sketch of the cave, showing the position of the sacrificial stone and triangle. By the time they had finished they were ready for their mid-day meal, and returned to camp for it.