when we're looking for
fresh lead, we've been down a deal, and we've been up a deal, 'bout as
much one as t'other. I should say we're just a little lower down than
when we started from that big water-hole, but not much."

"Made my back ache a bit, Dummy," said Mark, with a groan, as he leaned
himself against a column which was pleasantly smoothed and curved.

"Yes, we've come a good way," replied Dummy, "and you didn't have no
sleep last night."

The boy munched his last crust, and then lay flat down on his breast,
with his mouth over the pool, lowered his lips, and took a long deep
drink, after the fashion of a horse. After this, he rolled himself
clear away, and lay upon his back, staring at the two candles stuck in
the crack a few feet above his head.

"Does rest your back and lynes, Master Mark, to lie like this for a bit.
You just try it."

There was no reply.

"D'you hear, Master Mark? You try it."

Still no response, and he turned his head, to see that his companion's
chin was resting upon his chest.

"Sleep!" said Dummy, with a little laugh. "Can't stand being up all
night like I can. Being on night-shifts, sometimes, I s'pose. Well,
let him sleep for a few minutes, and then I'll wake him."

Then all was blank.

CHAPTER TWENTY THREE.

JUST IN TIME.

All at once Dummy Rugg uttered a peculiar snort, and started up in a
sitting position, with the thought still fresh in his brain that he must
rouse up Mark from his nap.

But all was dark, and there was the gurgling rush of the water below.
"Why, I've been asleep," muttered the lad excitedly. "Think o' me doing
that!"

He rose quickly, and felt for the crack in which he had stuck the
candles, narrowly escaping a plunge into the little pool from which he
had drunk.

He found the spot where the candles had been, both of them; he could
feel it by the size, and knew it by the shape, for it grew smaller at
each extremity, so that he had been able to wedge the ends of the
candles tight.

Yes: there was no doubt about it. Both candles, as if to be in fashion
with the stony drippings of the cavern, had run down a little, to form
tiny stalagmites of grease.

"Burnt right out," muttered Dummy, still more excitedly. "Why, I may
ha' been asleep for hours."

Thrusting his hand into his breast, there was a faint rattle as he drew
out tinder-box and match, and then felt for a candle in the box he had
carried slung by a strap from the shoulder,