"They heard us doing the same thing yesterday," answered Mackay; "an' they saw us too, so it's no vera likely they'll trouble us to-day. But if we put the drill-holes in deep enough, and give the powder plenty work to do, there shouldna be much noise—in fact, I doubt if they'll hear it at a'."
No time was lost in making the experiment, and the long steel drills were quickly grinding their way through the hard outer casing of the rock as nearly as could be judged opposite the place where the passage took an abrupt turn inwards. And now the mining knowledge of Mackay and Emu Bill made their work comparatively easy; they knew exactly the correct angles at which to drive the drills so as to obtain the best results when they loaded the holes so made with the deadly explosive. Steadily they laboured at their task, Bob, Jack, and the Shadow assisting at intervals, but more often engaged farther out in the open making a goodly appearance for the benefit of the natives, should they chance to be watching, and thus drawing attention away from the great work in hand. For a full hour Mackay slogged at the steel with his mighty hammer, then gradually the borings extracted from the deepening hole grew lighter and redder in colour, and the drill sank inwards rapidly.
"That's a new formation we've struck, Bill," said he, pausing to examine the edge of his tool. Then an exclamation broke from his lips. "We're chippin' through a gold lode!" he cried; "and it's so rich that the drill clogs in the metal."
"I reckon there's nary nig'll shift us from here now," said Emu Bill, examining for himself the gold grains exposed. "I means to see the other side o' this here mountain, or bust. I reckon there must be oceans o' gold an' di'monds over there."
At this stage Jack called out warningly, "I see old Nebuchadnezzar on the top of the mountain again."
"It's the same old nig that we didn't shoot," exclaimed the Shadow; "an', blow me! if he ain't goin' to throw stones at us."
The tall figure on the summit had certainly attempted to throw something down; but it caught on a jutting rock overhead, and bounded thence into the rising vapours of the hot springs. Once more he appeared to cast some projectile into the air; but if he did, it did not reach the ground in the vicinity of the anxious party beneath. Then again a visible missile came hurtling down; but it fell wide, much to the Shadow's satisfaction.
"The old fool can't throw stones for nuts!" he cried delightedly.
"I don't think he'll hurt us much," said Mackay, with a laugh. "Let him play away, Shadow, if it amuses him; it doesn't do us any damage."
And the individual aloft continued his strange pranks for some time, though in no one instance did the stones he threw alight even moderately near; then he vanished as suddenly as he had come.