The Secret Of Skull Mountain Part 19

They ran to the edge of the landing and listened There was no sound from the base of the shaft.

Joe knelt on the rocky floor and beamed his flash light at the foot of the drop-Clearly visible in thu fay of light was the narrow tunnel where the nigbfl before the boys had seen a swift-flowing stream oi oi water. water.

Now the tunnel was damp, 2>nd tiny pools of waten sparkled in the light. But the stream itself was not Sowing!

"That proves it!" Frank declared, his eyes s.h.i.+ning 'It's the tunnel which runs fu/m the reservoir!"

Bob nodded. "There's no doubt about it now/ he said slowly. He stared down at the damp chan nel. "There can be only one explanation why the water runs from the reservoir through that pa.s.sage at night-and not during the day," he added. "And that's a lock!"

He explained briefly to the boys how a simple lock could be set up in the tunnel to sluice or dam the How of the water at will.

"The lock is probably close to the mouth of tk< tunnel-where="" the="" channel="" is="" wider,"="" he="" concluded="" 186="" d.i.c.k="" grinned.="" "all="" we="" have="" to="" do="" now,"="" he="" pointed="" out,="" "is="" what="" we've="" been="" trying="" to="" do="" all="" along-locate="" the="" mouth="" of="" the="" tunnel="" in="" the="" valley="" and="" close="" it="">

Bob's mouth twisted wryly. "You're a cheerful soul," he told his friend.

"Maybe we could block off the tunnel here," Joe said eagerly, indicating the channel at the base of the shaft.

Bob shook his head. "The block wouldn't hold in such a small s.p.a.ce against the pressure of a fast-flowing stream," he replied.

Joe poked his flashlight at the jagged gap in the rock where the tunnel snaked underground toward the valley.

"As long as the water's dammed up during the day," he said hopefully, "one of us might be able to crawl through the tunnel to the mouth!"

"Nothing doing!" Frank told his younger brother promptly. "That hole is small enough as it is-and the pa.s.sage might get a lot smaller as it goes along!"

"Frank's right, Joe," Bob said. "It sounds like a nice way to commit suicide!" He sighed.

"We'll just have to keep hunting for the mouth of the tunnel till we find it."

"I think we'll know more when we explore the Tight-hand pa.s.sageway," said Frank.

But when they reached the fork, it was decided to press on to the top of the crevice and have lunch at 187 the camp before investigating the right-hand shaft.

They stood on the mountaintop and breathed the clear, cool air. Then Bob dropped the slab into place over the narrow opening of the cleft, and they started back to camp for a hasty lunch.

It was noon when the Hardy boys and the engineers again headed toward the ridge. But just as they entered the trail that led up the steep side of Skull Mountain, they heard a roar above them. A huge ma.s.s of rock, gravel and boulders was hurtling down the trail. It sounded like the roar of a great waterfall.

"Rockslide!" Bob yelled. "Take cover!"

For a horrified instant, they stood transfixed. Then, slipping and falling on the sliding gravel and loose, rolling stones near the foot of the slope, they scrambled for safety.

The sound of falling boulders, tree trunks and sliding gravel swelled into a roaring crescendo as the rockslide swiftly gathered momentum.

Giant, jagged rocks bounded past the boys and splashed into the water of the reservoir.

The entire slope appeared to be a roaring, ripping, writhing, tangled ma.s.s of boulders, mangled trees and sliding earth!

"Get behind this ledge-quick!" shouted Bob above the roar of i'he rockslide. He pointed to a solid ledge with a slight overhang about twenty feet from the reservoir.

188 The Secret of Skull M ountain The two boys and the engineers cowered behind the protecting ledge. From where they lay it looked as though the whole side of the mountain were moving.

Then, as though it were a hand roughly pulling aside a curtain, the rockslide tore away the dark-green patch of foliage just beyond where the terrified spectators were cowering.

Where the green patch had been, Frank, Joe and die engineers saw a gaping hole at the side of the slope, almost at the water's edge.

It was the mouth of the tunnel-the subterranean pa.s.sage which the Tarnack River, centuries before* had wain through the mountain to escape to the seaS

CHAPTER XXSIi.

Captured!

the rockslide stopped as suddenly as it had started The boys and the engineers waited until the last boulder had rumbled down the slope and splashed 5nto the reservoir, and the dust began to settle over the rock-torn area. Then they emerged from their shelter and started for the tunnel.

The tunnel's mouth, so unexpectedly revealed in the side of the slope, was an almost rectangular gap about twelve feet high and fourteen feet wide.

The floor of the tunnel was somewhat lower on the left side, and this depression obviously served as a sluiceway to carry water from the river through the subterranean pa.s.sage to Barmet Bay.

The Hardy boys, Bob and d.i.c.k stared at the secret tunnel with undisguised awe. Here before them was nature's own solution to a problem-a prehistoric outlet that a rus.h.i.+ng river, dammed up 189.

190 by a glacial moraine, had drilled through a mountain that it might escape to the seal Bob looked at the others. Then, as if in complete accord, unspeaking, they stepped into the boulder-strewn pa.s.sage.

Proceeding cautiously for a short distance into the tunnel, they saw that the sluiceway deepened gradually into a ditch which leveled off six feet below the floor of the main pa.s.sage. The tunnel itself sloped gradually downward.

The side walls of the tunnel were composed of shale and clay and limestone. In several places, the boys saw, the walls were pitted with freshly dug holes, and along the floor of the pa.s.sage were small piles of gray clay.

Frank pointed. "What do you make of them?" he asked Bob in a low voice.

The engineer knelt beside a pile and examined the clay with interest. Then he stood up and shook his head.

"Don't know," he replied. "Maybe we'll find out farther on."

Joe caught Bob's eye and pointed to deep imprints in a damp section of the floor.

Between the imprints were droppings of clay.

"Wheelbarrow tracks!" the boy whispered. "We must be getting close to the place where the gang is operating!"

The sunlight, streaming through the open mouth 191 of the pa.s.sage, had enabled the four explorers to see or a distance of several feet. But directly ahead, the tunnel twisted sharply and was lost in darkness.

"Gosh," said d.i.c.k. "We must have left our flashlights back there at the ledge where we took shelter."

"I'll go back to the camp and get a couple," Frank offered.

Joe, venturing as far as the turn, came back and intercepted his brother.

"We don't need flashlights," he said quietly. "Klenger's men have s.p.a.ced lanterns all along the pa.s.sage!"

In the flickering light of the lanterns, they saw that the water in the sluiceway, which had been a few feet deep at the mouth of the tunnel, was now almost level with the top of the ditch. And beyond a second bend in the pa.s.sage, they came to a crude but effective wooden lock.

It was modeled after a ca.n.a.l lock, with two door-like wings made of planks which met in the center. When the wings were closed, as they were now, the water was impounded.

Behind the lock, the ditch or ca.n.a.l was dry.

"There's the gadget that operates it," Bob whispered.

He indicated an iron wheel at the side of the tunnel, resembling the brake wheel of a railway freight car. By turning the wheel, Bob explained, the sluice gates could be opened and shut.

192 The boys studied the lock. It was clear now why the level of the water in the reservoir rose during the day and sank at night.

They continued along the pa.s.sage, the sound of their footsteps deadened by the shale and clay of the tunnel floor.

They were certain that the cavern in which the gang centered their activities must be fairly deep inside the mountain, otherwise the men surely would have heard the rockslide on the surface.

Suddenly, as they were about to turn another bend in the tunnel, they heard footsteps approaching. They scrambled back hastily and looked for a place in which to hide.

There was only one-the sluiceway.

"Into the ditch," Bob ordered in a barely audible tone. "And when you hear him round the bend-duck!"

They slipped noiselessly into the empty sluiceway and clung to the edge of the ditch. A moment later, they heard the footsteps rounding the bend.

All four held their breaths as the man pa.s.sed along the tunnel just above their heads.

They saw the man's face in the light of a lantern as he briefly inspected the lock. It was Sailor Hawkins. Satisfied, he started back down the pa.s.sage.

They lifted themselves out of the sluiceway the moment the old seaman had disappeared around the bend.

193 They moved forward again, their eyes searching eagerly for the cavern they knew must be ahead. Soon they came to a small cave cut in the wall of the tunnel, and Joe poked his head in for a look around.

He withdrew it with a start. On the floor of the cave was a stack of human skulls!

"The hermit's supply room," he whispered weakly.

Finally they arrived at their destination. A. cleft in the rock Avail of the main pa.s.sage sloped upward from the floor for several feet, then expanded into a deep cavern. The fissure narrowed again on the opposite side of the cavern, and rose gradually toward the top of the mountain.

Frank pointed to it as they stared into the giant cave.

"Must be the shaft which joins the other shaft at the fork," he whispered.

Bob nodded. "Flatten out," he ordered.

They lay flat on the sloping floor of the crevice, their heads just below the level of the cavern. Then, lifting their heads cautiously, they studied the occupants of the cave.

In one corner of the underground room Sailor Hawkins was sawing expertly through a wooden plank. The saw-toothed steel blade bit into the wood with swift, efficient strokes, and the boys observed that the seaman was cutting a board the same width and length as the planks in the wooden lock.

194 "Looks as though Hawkins built the lock," Bob whispered.

The boys looked at one another and grinned. They suspected that the old sailor had been pulling their leg when he told them the sad tale of his s.h.i.+p cracking up on a reef.

"Bet he was a s.h.i.+p's carpenter, instead of a s.h.i.+p's captain!" Joe breathed.

As they watched from their place of concealment, they saw the hermit. The thin, gaunt figure of the hermit came staggering down the shaft from the mountaintop, his arms laden with split cordwood. He dropped the wood on the floor of the cavern, then walked over to the corner of the room to the left of the shaftway.

Frank tugged at Bob's sleeve, and the engineer pa.s.sed the signal along to the others. A few feet to the left of the opening in the cavern wall a frail, slightly stooped, professorial-looking man with white hair was standing before a kiln, examining some gray clay he had taken from the oven. Beside the kiln stood a wheelbarrow, heaped with what looked like mud.

The mountain hermit approached the man at the kiln in a very deferential manner.

"That must be Dr. Foster!" Joe said in an excited whisper.

Frank nodded. "What's he doing?" he asked.

Joe shook his head, and Bob whispered back: 195 "I don't ktiOw. But it must be pretty important, or Klenger wouldn't be so anxious to keep the water from rising over the clay deposits in the valley."

"Think Foster is a member of the gang?" d.i.c.k queried.

"I doubt it," Frank replied, keeping his voice down. "He doesn't look like the sort of man who would get involved in anything crooked-unless he was forced."

Their eyes again turned to the kiln. The fire door below had been opened, and the man of the mountain was stoking it with wood. A cloud of smoke poured from the galvanized-iron stack which led from the kiln and into the shaftway beyond.

Here was the explanation for the columns o(' smoke they had so frequently seen. The smoke from the green wood was funneled up the shaft from the kiln. A column of smoke issued forth from the crevice at the top of the mountain only when the kiln was being stoked with green wood in the cavern far below.

As they watched, two men entered the cavern from a small bay a few feet at the right of the shaft. One was a stocky, surly-looking man with red hair. The other was a smaller man dressed in a clay-spotted business suit.

Frank started.

"The first man is Klenger!" he whispered to the others excitedly. "The smaller fellow is the stranger 196 who was with Klenger and Sweeper the night they cast me adrift!"

"Guess that accounts for everybody!" Joe whispered.

The two men joined Dr. Foster and stared at the kiln.

"What about it, Foster?" the stranger said impatiently. "Is it bauxite or not?"

Dr. Foster turned to the man.

"I've told you again and again, Mr. Stoper," he began, "I need more time to make the-"

"Time!" Stoper barked. "If I hear that word again, I'll go batty!" He stubbed his finger into the scientist's chest. "I want results-do you hear?"

"Take it easy, Ben," Klenger intervened, putting his hand on the smaller man's arm. "The old man's doing the best he can."

Bauxite! Ben!