"But we can go no farther," he said.

Leith's smile spread across his ugly flat face. "You are too young to
know everything," he sneered.

The youngster's eyes opened as he looked again at the circular pit with
its brilliantly tinted sides. The answer perplexed him, and he waited
anxiously for an explanation.

"But how can we?" he asked.

Leith stood for a moment before replying, then he moved closer to the
edge of the crater and pointed down.

"The road is directly beneath you," he remarked. "If you come closer to
the edge you can see it." Holman glanced at me in amazement, and moved
by the one impulse we stepped toward the ledge. The rim of the vast pit,
at the point where Leith was standing, was composed of porphyry of a
dark-green shade, and as we neared the edge we noticed that this had
been worn to that peculiar velvety smoothness that one notices on the
pillars of Indian temples, where the sweaty hands of millions of
worshippers have helped in the polishing process through unnumbered
centuries.

Leith noticed that our glances were directed upon the peculiar polished
portion of the rim, and his grin broadened.

"You won't be the first to go over on to the track below," he drawled.
"If I had a dollar for every man who slipped over here since the world
began I wouldn't bother with specimens for American and European