the southeast. After a mile he stopped and
hurriedly set the apparatus up again. This time the crystalline signal
came in with a noticeable increase in volume.

From then on the progress of the party became a mad dash that taxed the
endurance of everyone except Layroh himself. After the first hour they
entered a terrain so rugged that the cars had to be abandoned and they
fought their way forward on foot. Layroh was forced to turn the
radiolike apparatus over to one of the men, while he himself carried
another mechanism that consisted of a heavy silver cylinder with four
flexible nozzles emerging from one end.

They held as rigidly as possible to a straight line toward the
southeast, scrambling over whatever obstacles intervened. Their only
stops were at regular intervals when Layroh checked their course. Each
time the crystalline signal came in with greater volume.

Their objective appeared to be a cone-shaped peak several miles ahead
that loomed up high above the surrounding rock masses. The oddly shaped
mountain was identified by one of the men who had once been a Mojave
desert rat.

"Lodestone Peak," he announced succinctly. "Full of iron, or somethin'.
A compass always goes haywire within a radius of ten miles of it."

* * * * *

It was early afternoon when they finally arrived at a level area at the
base of the mountain. For the last two miles Layroh had not stopped long
enough to make any tests. Now he set the radiolike apparatus in place
some ten yards from the face of a sheer cliff that towered high above
them.

The crystalline signal came in a rippling flood. He spun the dials. The
sound ceased, and the pointing rods glowed with an aura of amber light
at their tips. Swift and startling answer came from deep within the
heart of the cliff, a mighty note of sonorous beauty like the violent
plucking of a string on some colossal bass viol. So powerful was the
timbre of the pulsing sound that the entire side of the mountain seemed
to vibrate in harmony with it.

Layroh snapped off the apparatus and the sound ceased. Carefully
searching until he found a certain spot on the cliff face, he stepped
close to it and unlimbered the nozzles of the silver cylinder. Foster
noted that at the place selected by Layroh there was a five-foot-wide
stratum of slightly lighter-colored rock extending from the sand to a
point high up on the cliff face.

From the metal nozzles of the cylinder t