THE END OF DEATH VALLEY

Hurrying along, some of the men in their saddles, others stumbling on
foot, not having taken the time to mount, the whole party rushed out of
the defile. It was not until they had reached open country, some
distance removed from the entrance to Smugglers' Glen, that the older
scientist thought it safe to call a halt. And he did not do this until
he had looked around, with his assistant, to make sure there were no
earth fissures near, and had also ascertained the direction of the
wind. He tested the air by breathing deeply of it and said:

"We're safe for a time. But there's no telling how long. This is a
most remarkable natural phenomenon--one of the most remarkable I have
ever happened upon."

"Very remarkable," agreed Professor Snath.

"But what's it all about?" asked Bud. "We've seen those earth cracks
before."

"And near the place where there were dead cattle," added Nort.

"We heard running water down below, too," was Dick's contribution to
the general information.

"Those cracks go down to the bed of an underground stream," explained
Professor Dodson. "The subterranean river, brook or whatever it is,
must flow a long distance under this ranch," and he looked over the
expanse of valley, hill and plain. "Now an ordinary underground stream
is not dangerous. In fact where it comes to the surface, as many do,
it provides valuable water. But the stream below here is impregnated
with a deadly gas." He gave it a long Latin name. "At least if it is
not always deadly," he went on, "and it may not be so at all times,
owing to dilution, it is risky to breathe it. I think that is the
explanation of the deaths of your cattle," he said to Bud. "And you
men who were rendered unconscious," he indicated Sam and his guards,
"you must have breathed a modified form of the gas."

"But those fellows had gas in tanks!" cried Nort.

"No question about that!" added Billee. "Did they bottle up this stuff
you gave such a long name to, Professor, and shoot it out at us?"

"No," was the answer. "I am inclined to think these unknown men used a
very different kind of gas against you--probably a comparatively
harmless vapor discovered during the war activities. I think there are
two puzzles here and that they are both in the way, now, of being
solved."

"It looks so," murmured Bud. "But how is the poison gas generated and
how does it come up out of cracks in the earth to kill cattle and