“How about feeding the lions?” asked Emett.

“They’ll drink to-night,” replied Jones, “but won’t eat for days; then we’ll tempt them with fresh rabbits.”

We made a hearty meal, succeeding which Jones and I walked through the woods toward the rim.  A yellow promontory, huge and glistening, invited us westward, and after a detour of half a mile we reached it.  The points of the rim, striking out into the immense void, always drew me irresistibly.  We found the view from this rock one of startling splendor.  The corrugated rim-wall of the middle wing extended to the west, at this moment apparently running into the setting sun.  The gold glare touching up the millions of facets of chiseled stone, created color and brilliance too glorious and intense for the gaze of men.  And looking downward was like looking into the placid, blue, bottomless depths of the Pacific.

“Here, help me push off this stone,” I said to Jones.  We heaved a huge round stone, and were encouraged to feel it move.  Fortunately we had a little slope; the boulder groaned, rocked and began to slide.  Just as it toppled over I glanced at the second hand of my watch.  Then with eyes over the rim we waited.  The silence was the silence of the canyon, dead and vast, intensified by our breathless earstrain.  Ten long palpitating seconds and no sound!  I gave up.  The distance was too great for sound to reach us.  Fifteen seconds—­seventeen—­eighteen—­

With that a puff of air seemed to rise, and on it the most awful bellow of thunderous roar.  It rolled up and widened, deadened to burst out and roll louder, then slowly, like mountains on wheels, rumbled under the rim-walls, passing on and on, to roar back in echo from the cliffs of the mesas.  Roar and rumble—­roar and rumble! for two long moments the dull and hollow echoes rolled at us, to die away slowly in the far-distant canyons.

“That’s a darned deep hole,” commented Jones.

Twilight stole down on us idling there, silent, content to watch the red glow pass away from the buttes and peaks, the color deepening downward to meet the ebon shades of night creeping up like a dark tide.

On turning toward the camp we essayed a short cut, which brought us to a deep hollow with stony walls, which seemed better to go around.  The hollow, however, was quite long and we decided presently to cross it.  We descended a little way when Jones suddenly barred my progress with his big arm.

“Listen,” he whispered.

It was quiet in the woods; only a faint breeze stirred the pine needles; and the weird, gray darkness seemed to be approaching under the trees.

I heard the patter of light, hard hoofs on the scaly sides of the hollow.

“Deer?” I asked my companion in a low voice.

“Yes; see,” he replied, pointing ahead, “just right under that broken wall of rock; right there on this side; they’re going down.”

I descried gray objects the color of the rocks, moving down like shadows.