of the living rock, heard even the faintest, most fleeting sound. As the watcher sat there waiting and listening, whilst the minutes slowly passed, he found himself—at any rate, I know that I did—almost wishing that some pulsation would come, so heavy and awful was the stillness of the place.
But a sound we were to hear. We had been journeying for about an hour and a half and had just passed below sea-level. In that place Rhodes had left the aneroid. Of a sudden Milton, who was leading the way, halted with a low, sharp interjection for silence. When my look struck him, he was standing in an attitude of the most riveted attention.
"There?" he exclaimed. "Did you hear that, Bill?"
The air had pulsed to the faintest sound; now all was still again.
"What was it?" I asked, my voice a whisper.
"Don't know, Bill. There!"
Again that gentle pulsation touched the ear, and again it/was gone. And a strange thing was that, for the life of me, I could not have told whether it came from below or from behind us.
"There it is again?" said Rhodes. I flashed on my electric light, to the full power.
"A whisper!" I exclaimed. "And, great heaven, Milton!"
"What now, Bill?" he asked quickly.
"It's something behind us!"
He started. He turned his light up the tunnel, and for some moments we stood peering intently. Not a moving thing was to be seen there, however—only the moving shadows.
"Again!" said Milton Rhodes. "But it isn't a whisper, Bill. And it didn't come from up there."
"The thing," I told him, "could be hiding in shadow."
"It's not up there; it is ahead."
"Wherever it is, what on earth can it be?—what does it mean?"
"That we shall learn."
We resumed our descent, every
sense, you may be sure, on the
qui vive. The tunnel here inclined
rather steeply; a little space, however,
and the dip was a gentle one. The
sounds soon became ono steady, unbroken
whisper; then a dull melancholy
murmur.
Abruptly Rhodes stopped, turned to me, and he laughed.
"Know now what it is, Bill?"
This was not a moment, I thought, for laughter or anything like it.
"Sounds like the growling of beasts," I said, peering intently down the passage. "I wonder if the angel—there are two kinds of angel, you know—has turned loose a whole pack, or flock, of those demons."
To my surprize and astonishment, Rhodes burst into outright laughter.
"Well?" said I rather testily.
"Why all the cachinnation?"
"Forgive me, Bill. But it isn't a pack of demons—or a flock."
"How on earth do you know what it is?"
"It's water."
"Water?"
"Yes. H-two-O."
"Water? I'm from Missouri. You'd better see that your revolver is handy. Who ever heard water make a shivery sound like that?"
"You'll see, though I think that you'll hear first."
Ere long there could be no doubt about it: Milton was right; it was the sound of falling water.
"Must be at quite a distance," I said; "sounds carry a long way in tubes, and that is what this tunnel is."
Steadily we made our way along and down, and, just as steadily, the sound increased in volume. The gallery made several sharp turns, and then of a sudden the sound rose from
