Laborers came tumbling out of the tents. Many of them had slept so
soundly that even the noise of dynamiting they had regarded only as a
part of their dreams. But the whistle meant business.

"Get the torches out, Mr. Rivers," called Tom, as one of the foremen
reported on a run.

To Foreman Payson, Harry gave the order to marshal a hundred of the men
to remain in and around the camp, alertly watchful.

"That's a good idea," nodded Mr. Ellsworth. "The explosion may be only a
trick to, empty the camp, as a prelude to further mischief."

Scores of torches flared in the darkness as the workmen hurried
westward. At the head of all went Tom Reade and the general manager.

Less than half a mile away they came upon the scene of mischief.

"It's just what I expected," nodded Tom, as the leading party halted
under the flare of the torches. "You see, sir, here was the point of
greatest cave and drift in the quicksand. It's where your former
engineers found such a morass of the shifty stuff that they declared the
Man-killer never could have its appetite satisfied with dirt. There was
a good log and concrete foundation laid down there, and for thirty-six
hours the sand had not shifted a particle as far as the eye could
discover. Now, look at it!"

Before them the top layer of desert sand had sunk away, revealing a well
or sink, one hundred and fifty feet across and the bottom at least forty
feet below the general level.