Chapter XVIII. Finding the Tunnel
 

In silence, broken only by the noise of the motor, did the gold- seekers approach the temple. As they neared it they could see its vast proportions, and they noted that it was made of some white stone, something like marble. Then, too, as they drew closer, they could see the desolate ruin into which it had fallen.

"Looks as if a dynamite explosion had knocked it all apart," observed Ned.

"It certainly does," agreed Mr. Damon.

"Maybe Cortez, or some of those early explorers, blew it up with gunpowder after fighting the Aztecs, or whatever the natives were called in those days," suggested Tom.

"Bless my bookcase! You don't mean to say you think this temple goes back to those early days," spoke Mr. Damon.

"Yes, and probably farther," declared Tom. "It must be very ancient, and the whole country about here is desolate. Why, the way the woods have grown up everywhere but on this plain shows that it must be three or four hundred years ago. There must have been a city around the temple, probably Poltec, and yet there isn't a trace of it that we have seen as we came along. Oh, yes, this is very ancient."

"It will be jolly fun to explore it," decided Ned. "I wish it wasn't so near night."

"We can't do much now," decided Tom. "It will be too dark, and I don't altogether fancy going in those old ruins except by daylight."

"Do you think any of those old Aztec priests, with their knifes of glass, will sacrifice you on a stone altar?" asked Ned, with a laugh.

"No, but there might be wild beasts in there," went on the young inventor, "and I'm sure there are any number of bats. There must be lots of nooks and corners in there where a whole army could hide. It's an immense place."

The ruined temple certainly was large in extent, and in its glory must have been a wonderful place. The balloon came nearer, and then Tom let it sink to rest on the sand not far from the ancient ruin. Out he leaped, followed by his friends, and for a moment they stood in silent contemplation of the vast temple. Then as the last rays of the setting sun turned the white stones to gold, Tom exclaimed:

"A good omen! I'm sure the city of gold must be near here, and in the morning we'll begin our search for the secret tunnel that leads to it."

"That's the stuff!" cried Ned enthusiastically.

An instant later it seemed to get dark very suddenly, as it does in the tropics, and almost with the first shadows of night there came a strange sound from the ruined temple.

It was a low moaning, rumbling sound, like a mighty wind, afar off, and it sent a cold shiver down the spines of all in the little party.

"Good land a' massy! What am dat?" moaned Eradicate, as he darted back toward the balloon.

"Bless my looking glass!" cried Mr. Damon.

A second later the noise suddenly increased, and something black, accompanied by a noise of rapidly beating wings rushed from one of the immense doorways.

"Bats!" cried Tom. "Thousands of bats! I'm glad we didn't go in after dark!" And bats they were, that had made the noise as they rushed out on their nightly flight.

"Ugh!" shuddered Mr. Damon. "I detest the creatures! Let's get under cover."

"Yes," agreed Tom, "we'll have supper, turn in, and be up early to look for the tunnel. We're here at last. I'll dream of gold to- night."

Eradicate soon had a meal in preparation, though he stopped every now and then to peer out at the bats, that still came in unbroken flight from the old temple. Truly there must have been many thousands of them.

Whether Tom dreamed of gold that night he did not say, but he was the first one up in the morning, and Ned saw him hurrying over the sands toward the temple.

"Hold on, Tom!" his chum called as he hastened to dress. "Where you going?"

"To have a hunt for that tunnel before breakfast. I don't want to lose any time. No telling when Delazes and his crowd may be after us. And the Fogers, too, may strike our trail. Come on, we'll get busy."

"Where do you think the tunnel will be?" asked Ned, when he had caught up to Tom.

"Well, according to all that Mr. Illingway could tell us, it was somewhere near this temple. We'll make a circle of it, and if we don't come across it then we'll make another, and so on, increasing the size of the circles each time, until we find what we're looking for."

"Let's have a look inside the temple first," suggested Ned. "It must have been a magnificent place when it was new, and with the processions of people and priests in their golden robes."

"You ought to have been an Aztec," suggested Tom, as he headed for one of the big doorways.

They found the interior of the temple almost as badly in ruins as was the outside. In many places the roof had fallen in, the side walls contained many gaping holes, and the stone floor was broken away in many places, showing yawning, black caverns below. They saw hundreds of bats clinging to projections, but the ugly creatures were silent in sleep now.

"Bur-r-r-r-r!" murmured Ned. "I shouldn't like any of 'em to fall on me."

"No, it's not a very nice place to go in," agreed Tom.

They saw that the temple consisted of two parts, or two circular buildings, one within the other. Around the outer part were many rooms, which had evidently formed the living apartments of the priests. There were galleries, chambers, halls and assembly rooms. Then the whole of the interior of the temple, under a great dome that had mostly fallen in, consisted of a vast room, which was probably where the worship went on. For, even without going farther than to the edge of it, the youths could see stone altars, and many strangely-carved figures and statues. Some had fallen over and lay in ruins on the floor. The whole scene was one of desolation.

"Come on," invited Tom, "it's healthier and more pleasant outside. Let's look for that tunnel."

But the lads soon realized that it was not going to be as easy to locate this as they had hoped. They were looking for some sort of slanting opening, going down into the earth--the entrance to the underground city--but though they both made a complete circuit of the temple, each at a varying distance from the outer walls, no tunnel entrance showed.

"Breakfust! Breakfust!" called Eradicate, when Tom was about to start on a second round.

"Let's eat," suggested Ned, "and then we four can circle around together." Tom agreed that this would be a good plan. A little later then, with Tom nearest the temple walls, the four began their march around them.

Four times that morning they made the circuit, and the same number in the afternoon, until they were nearly half a mile away from the ruin, but no tunnel showed.

"Well, we'll have to keep at it to-morrow," suggested Tom. "It's too soon to give up."

But the morrow brought no better success, nor did the following two days. In fact for a week they kept up the search for the tunnel, but did not come upon it, and they had now pretty well covered the big plain. They found a few ruins of the ancient city of Poltec.

"Well, what about it?" asked Ned one night as they sat in the balloon, talking it over. "What next, Tom?"

"We've got to keep at it, that's all. I think we'll go up in the balloon, circle around over the plain at just a little elevation, and maybe we can spot it that way."

"All right, I'm with you."

But they did not try that plan. For in the middle of the night Ned suddenly awakened. Something had come to him in his sleep.

"Tom! Tom!" he cried. "I have it! What chumps we were!"

"What's the matter, old man?" asked Tom anxiously. "Are you sick-- talking in your sleep?"

"Sleep nothing! I've just thought of it. That tunnel entrance is inside the temple. That's the most natural place in the world for it. I'll bet it's right in the middle of the big inner chamber, where the priests could control it. Why didn't we look there before?"

"That's right; why didn't we?" agreed Tom. "I believe you're right, Ned! We'll look the first thing in the morning."

They did not wait for breakfast before trying the experiment, and Mr. Damon and Eradicate went with Tom and Ned. It was no easy work to make their way over the ruins to the inner auditorium. Wreckage and ruin was all around, and they had to avoid the yawning holes on every side. But when they got to the main, or sacrificial chamber, as Ned insisted on calling it, they found the floor there solid. In the centre was a great altar, but to their chagrin there was not a sign of a tunnel opening.

"Fooled again!" said Tom bitterly.

"Maybe some of those holes outside is the entrance," suggested Mr. Damon.

"I don't believe so," objected Tom. "They seemed to go only to the cellar, if a temple has such a thing."

Bitterly disappointed, Tom strolled over and stood in front of the big stone altar. It seemed that he must give up the search. Idly he looked at the sacrificial stone. Projecting from it was a sort of a bundle.

Tom took hold of it, and to his surprise he found that it could be moved. Hardly knowing what he was doing, he pulled it toward him.

The next instant he uttered a cry of horror, for the immense stone altar, with a dull rumbling, rolled back as though on wheels, and there, over where it had stood was a hole of yawning blackness, with a flight of stone steps leading down into it. And Tom stood so near the edge that he almost toppled in.

"Look! Look!" he cried when he could get his gasping breath, and step back out of danger.

"The tunnel entrance!" cried Ned. "That's what it is! You've found it, Tom! The entrance to the city of gold at last!"