truck and went down the road to take up guard
positions.

Rick and Tony went to the truck and took the earth scanner from Scotty.
They carried it to the edge of the natural terrace and set it up. The
others joined them, weapons in hand.

Chahda watched with special interest as the covers were taken from the
portable boxes. He had never seen the earth scanner in operation.

"Plenty magic, I bet. You scientists make poor native boy scared with
this machine."

Rick snorted. "Come on and be useful, poor native boy. Connect these
leads for me. They go into the Fahnestock clips on those A batteries."

Chahda made the connection with the ease of one who has worked with
electronic apparatus before, but he kept muttering about how the poor
native boy was "plenty snowed" by wonderful scientists. Rick just
grinned and went ahead with connecting up the scanner. Tony didn't quite
know what to make of Chahda at first, but soon the Hindu boy's dexterity
convinced him that Chahda was pulling his leg.

Scotty threatened Chahda with the butt end of his rifle. "I'd offer you
to the Ifugaos, if I didn't know they can't use empty heads."

"You let that poor native boy alone," Rick said with false concern. He
lifted the probe from its foam rubber-lined receptacle and plugged its
cord into the control panel. The earth scanner was ready to operate.

Its appearance was not unusual. There was a power pack, consisting of
batteries and a dynamotor, an amplifier, and a control panel. In the
control panel was an oscilloscope. The probe looked like an aluminum
pipe but was really a special tube built like a segment of coaxial
cable. The sensing unit was in an inner core, surrounded by an
atmosphere of pressurized helium. At the tip of the probe was the
sensing element which looked very much like the Geiger tube of a
radiation detector surrounded by a helical coil.

"Come on, you poor native, and I'll show you how it works," Rick
invited.

"You not expect to find stuff here. You just testing?" Chahda asked.

"We want to get a standard pattern," Rick said. He pointed to the
valley. "The terrace soil and rocks should be no different than those
right here. So we'll get the typical response of these, and when we get
to our location we won't have to take time--which could be important if
we have Ifugao spear throwers shooting at us."

"What's typical response?" Chahda asked.

Rick showed him the helical coil at the end of the probe. "This co