CHAPTER III
Firing Parties
It was a shaken group of scientists that moved off in their jeeps to thepreselected stations. Most of the adults had experienced earthquakesbefore, but none had seen the earth split almost at their feet. To Rick,the sensation had been as upsetting as any he had ever experienced.
"The one thing we learn to depend on," Zircon said, "is that the earthunder our feet is solid and dependable. When it shakes like a jelly, itcauses a kind of emotional shock, apart from any physical damage it maydo."
"It certainly did with me," Rick agreed.
"Ditto," Scotty added.
Zircon put the jeep in gear and moved away from the hotel. He droveslowly over the narrow part of the crack in the parking lot, then pickedup speed. Rick looked around. Bradley Connel and Ruiz were following intheir own vehicle.
Zircon took a blacktop road to the west, close to the base of themountain. Fortunately for Rick's peace of mind, the road was fairlysmooth. He had never carried dynamite caps before, but he knew theycontained fulminate of mercury, which is one of the most unstable andviolent chemical substances, pound for pound, ever created.
The big scientist sensed his uneasiness. "Relax, Rick. Those caps won'tgo off without a substantial knock against something. Enjoy thescenery."
Rick grinned. "I'll try."
The scenery was tropical. Once away from the hotel grounds, there washeavy growth, vines, creepers, and broad-leafed plants. He saw palmettoand wild banana interspersed with Judas palms and other typicalvegetation. The growth clung to the side of El Viejo like a thick greencarpet. Now and then the jeep passed an open space in the vegetation andhe saw the plains stretching away to the sea on his left.
The jeep climbed gradually and Rick realized that their direction hadchanged. They were now heading on the more northerly course. Thevegetation was thinner, too, and he guessed it was because they werehigher up the mountainside. At a rough estimate, the jeep had climbednearly a thousand feet.
"Pumice quarry ahead," Zircon announced.
Rick saw ramshackle wooden buildings, then piles of grayish rock. Ahundred yards farther on he saw an open pit. This was where the SanLuzians mined pumice for export.
"Is there much of a market for it?" Scotty asked.
"Not as much as there was years ago," Zircon replied. "Pumice, as youprobably know, is volcanic rock. But not an ordinary one. It's a kind offoamy lava honeycombed with gas bubbles. It's used as an abrasive.Modern industrial products have replaced it in general use, butapparently there's still enough demand so that the San Luzians are ableto export a little. Our firing station is about a mile from here."
Rick looked at the rough terrain. "Think we can get through?"
"Easily. According to the map, we have an unpaved road part of the way."
The unpaved road turned out to be a pair of wagon tracks. But at leastthere were no trees in the way. Rick held on tight as Zircon shiftedinto four-wheel drive and forged ahead.
The big scientist kept an eye on his odometer, or mileage counter, whilethe boys watched for a clearing. It was slightly over a mile before theyfound one, and Zircon pulled off the road to let Brad Connel and Ruiz goby.
The jeep stopped as the two came abreast and the geologist called, "Wantto trade stations?"
"We like this one," Zircon replied with a grin.
"Don't blame you. I have another three miles through this stuff. Well,so long."
The jeep started off and was soon lost as the path curved slightly.
Zircon looked at his watch. "Plenty of time, but we might as well getready."
A few minutes search disclosed a spot far enough away from the clearingfor safety, with no trees to be uprooted by the blast. Zircon took twoof the dynamite sticks Rick carried and one of the caps. He placed thecap over one stick and used a special tool, like a jar opener, to crimpit into place.
"This is the only really delicate part of the operation," he said. "Ifthe crimpers slip, they could set off the cap and the dynamite. So becareful when you do it. Keep the crimpers low on the flange of the cap."
He found a rubber band in his pocket and used it to hold the two stickstogether. A coil of wire was produced next, and the connection made tothe dynamite cap. Zircon dug a shallow hole with his heel and put thedynamite sticks in, then backed off unwinding wire as he went.
The detonator had been left in the jeep. Rick got it and carried it towhere Zircon waited with the pair of wires.
"How does this thing work?" Scotty asked.
"It's a dynamo," Zircon replied. "When the handle is pushed down itengages gears that spin a flywheel, which operates the dynamo longenough to send an electrical charge through the wires."
"So don't sit on the handle," Rick joked.
"And don't kick it," Scotty added.
Zircon connected the wires to a pair of terminals on top of thedetonator, then looked at his watch. "Plenty of time. We might as welltake it easy. Anyone hungry?"
No one was. It was too soon after breakfast. Instead, Rick took theopportunity to ask questions.
"I can understand the general principle of what we're doing, but can youtell us exactly what happens?"
"Sure. When the dynamite charge goes off, it sends shock waves throughthe earth in all directions. Whenever a shock wave strikes something ofdifferent density, its direction and velocity change. For instance, ifthere is denser rock a few hundred feet down, that will cause a changeof both velocity and direction. With me so far?"
"I think so," Scotty said. "The denser the stuff the wave strikes, thefaster it moves. Like sound waves. I mean, sound moves faster in waterthan in air, and faster in a steel rail than in water. Is it the same?"
"Just about," Zircon agreed. "The shock waves radiate away from us,through the earth, and eventually reach the recorders on the other sideof the mountain. You can see what happens, I think. Waves will arrive atdifferent times, depending on the path they took and the kind ofmaterial they went through."
Rick nodded. "So if there's molten rock, or magma somewhere in the way,the shock wave that goes through it will slow down and arrive at therecorder later?"
"That's it. The tracings we get can be analyzed to give us a kind ofcross-sectional look at the mountain. You see, we know how fast thewaves travel through different kinds of earth structure. Also, we willknow the point of the explosion and the location of the recorder foreach shot. Which reminds me. We'd better get out the equipment andlocate ourselves precisely."
"How?" Rick asked. "What will we use for landmarks?"
"The top of the mountain, for one, and if you'll look carefully to apoint slightly south of east between those two banana palms, you'll seethe top of the control tower at the airport."
Rick shook his head. "Good thing you're with us. I completely forgot towatch for landmarks."
"That was the first thing I had in mind in looking for a spot," Zircontold him.
The transit gave a precise angle between the two landmarks. Zircon drewa line on the map connecting the southern tip of the mountain and theairport tower. Then, with that as his base line, it was easy to draw twolines at the correct angles from each of the points. The transit'sposition was where the two lines intersected.
By the time the scientist had finished, it was nearly one o'clock. Thethree walked to the detonator. "Pull the handle up," Zircon directed.Rick did so. "I'll count down from ten seconds. Push down on zero."
It was like the countdown for a rocket firing, Rick thought. Zirconcalled out the time starting at one minute, then called off the last tenseconds. As he reached zero, Rick pushed the handle home.
The dynamite went off with a roar that sent leaves and dirt flying, andRick felt the shock wave slam against his ears with stunning force.
"Open your mouth next time," Zircon said. "I forgot to warn you." He wasalready reeling in the wire. "Let's get going. One mile farther on forthe next shot."
At the next station the same procedure was repeated, but before it wastime, there
was a far-off explosion. Zircon looked at his watch. "BradConnel. Right on time." In another fifteen minutes there was an evenmore distant sound as David Riddle's first shot went off. They ate theirlunch and listened to the echo off the mountain.
Zircon and the boys were ready when their time came. Location this timehad been made on sightings toward the mountain, and a flagpole at CapeSan Souci on the western side of the island.
The road petered out and they were forced to go cross-country to reachthe third shot station. Fortunately, Brad Connel had left a path ofcrushed vegetation, so it was only necessary to follow where he had led.
After the third shot, the three collected their equipment and drove backto the hotel.
They were the first back. All three were sticky from the heat, andsomewhat insect bitten. By unanimous consent they headed for theshowers.
Rick dressed except for his shoes, then stretched out on his bed. Hewondered what the day's work would show. The memory of the earthquakewas still fresh, and he was anxious to see if it had come from risingmagma far below, or from some other source. He had a mental image ofwhite-hot rock rising sluggishly, melting a path to the surface. Now andthen the magma struck water, or gas-producing minerals, and then therewas a tightly held explosion that made the earth shudder.
Well, it was probably like that, from what he had read about volcanicaction. Anyway, he could do without earthquakes. They were unnerving.
Scotty finished dressing, and Rick slipped on his shoes. It was time forthe others to be back. Connel should have arrived only a few minutesbehind them, but it would take longer for the others because they hadgone around the mountain in the other direction.
The boys walked to the staff conference room and found Hartson Brant andJulius Weiss. The two were busy unrolling long strips of paper coveredwith blue shadings.
"Find anything yet?" Rick asked his father.
"No. We're just getting ready to take a look. How did it go?"
"No trouble. Zircon must still be in the shower. Probably Connel is,too. He must have been right behind us."
The scientists started poring over the traces.
"Here's your first shot," Hartson Brant said. He pointed to where aseries of squiggles began. Rick could see nothing of interest. All thepen marks looked about the same to him. It would take expert analysis tomake anything out of them.
The boys left the scientists to their work and wandered out into theparking lot. "I want to take a closer look at that crack," Rick said.
"Same here. Suppose it goes to China?"
Rick grinned at his pal. "That's a myth. If you drilled a hole straightdown through the center of the earth from here you wouldn't come outanywhere near China. You'd be in the Southern Hemisphere."
"Don't get technical on me, boy."
The crack, however, went down only about three feet, gradually narrowinguntil it was closed. Even so, it was impressive. Rick knew that theactual break must continue down into the earth for some distance,perhaps for hundreds of feet. The force it took to shake the earth likethat was awesome. Again he was reminded sharply of the kind of forcesagainst which the Spindrift group was trying to contend, and he felt forthe first time that the job was completely hopeless. What could mere mendo?
A horn honking wildly brought him to quick attention. He turned and sawa jeep coming along the western road into the parking lot. Brad Connel!But where was Ruiz? Then, as the jeep neared, Rick saw. The San Luzianwas lashed to an improvised stretcher lying across the back of the jeep!
The geologist drew to a stop, his face chalky.
"Get a doctor!" he shouted. "Quickly! Ruiz got caught in the lastexplosion. I think he's dead!"