"Arthur, Robert - The Three Investigators 010 - The Mystery of the Moaning Cave" - читать интересную книгу автора (Arthur Robert)

"Water erosion mostly," Bob explained. "I've read about it in the library. A mountain like this is made up of different rocks, some softer than the others. The water comes in and wears away the softer rock. It takes millions of years sometimes. A lot of this area was under water a long time ago."

"Bob's right," Jupiter said. "But I'm not sure that all of these passages are natural. Some of them look man-made. Maybe by El Diablo's men."

"Or miners, Jupe," Bob said. "I read how they used to look for gold around here."

Pete was shining his light at first one passage, then another. "Where do we start looking?" he asked.

"It could take us months to search all these passages," said Bob. "I'll bet each one branches out again farther on."

"Probably," Jupiter agreed, "but fortunately we have an easy way to eliminate some of them. We're looking for the moaning sound. All we have to do is listen at each entrance until we find the one where the moaning is coming from."

"Hey, that's right," Pete said with enthusiasm. "We'll just follow the moaning."

"But Jupeа.а.а." Bob was looking puzzled. "The moaning. I don't hear it. I mean, I haven't heard it since we came inside!"

The three boys stood perfectly still, listening intently. Bob was right--the cave was as quiet as a tomb.

"Jupe?" Pete said uneasily. "What does it mean?"

Jupiter shook his head in puzzlement. "I don't know. Maybe it's just a coincidence. Maybe it'll start again soon."

But the moaning did not start. Ten minutes passed and there was no sound inside the cave.

"I remember hearing it just before that rock fell, Jupe," said Bob. "Only I wasn't listening much after that."

"We were too excited to think about it," Jupiter said. "We can't really be sure when it stopped."

"Gosh," Pete said, "what do we do now?"

"Perhaps it will begin again," Jupiter said hopefully. "Mr. Dalton did say the cave moans irregularly. While we're waiting, I think we should start to search the side passages one by one."

Bob and Pete agreed. Anything would be better than just standing there in the spooky darkness. "Bob chalked a question mark and an arrow at the entrance to the first side passage, and the boys entered the tunnel.

They moved cautiously, their flashlights probing ahead until, less than thirty feet from the entrance, the tunnel suddenly ended. It did not end in a blank wall but in a pile of fallen rock that completely blocked the passage.

"Mr. Dalton said many of the tunnels were blocked by old earthquakes," Bob recalled.

Pete looked worried. "Do you think it's still dangerous?"

"No," Jupiter said. "The ceilings are very solid. It took a heavy shock to make these rocks fall, and then only the very weakest places fell. This is a very safe cave."

They retraced their steps, and tried the next four tunnels, carefully marking each entrance. All four passages ended in piles of fallen rocks.

"We're wasting time," said Jupiter finally. "We'll split up and each search a passage. They seem quite safe."

"We'll each go through our tunnel until we can see the end," Bob agreed, "unless it turns out not to be blocked."

"That's it," Jupiter said. "If one of us finds a clear passage he can come back and wait here for the others."