"It's an underground passage all right," said Professor Bumper eagerly; "and not a natural one, either.That was fashioned by the hand of man, if I am any judge.It seems to go right under the mountain, too.Friends, we must explore this! It may be of the utmost importance! Come, we have our electric torches, and we shall need them, for it's very dark in there," and he peered into the passage in front of which they all stood now.It seemed to have been tunneled through the earth, the sides being lined by either slabs of stone, or walls made by a sort of concrete.
"But what about the rescue work?" asked Mr.Damon.
"I am not forgetting Professor Beecher and his friends," answered the scientist.
"Perhaps this may be a better means of rescuing them than by digging them out, which will take a week at least," observed Tom.
"This a better way?" asked Ned, pointing to the tunnel.
"That's it," confirmed the savant."If you will notice it extends back in the direction of the cave from which we were driven.Now if there is a buried city beneath all this jungle, this mountain of earth and stones, the accumulation of centuries, it is probably on the bottom of some vast cavern.It is my opinion that we were only in one end of that cavern, and this may be the entrance to another end of it.""Then," asked Mr.Damon, "do you mean that we can enter here, get into the cave that contains the buried city, or part of it, and find there Beecher and his friends?""That's it.It is possible, and if we could it would save an immense lot of work, and probably be a surer way to save their lives than by digging a tunnel through the landslide to find the mouth of the cave where we first entered.""It's a chance worth taking," said Mr.Damon."Of course it is a chance.But then everything connected with this expedition is; so one is no worse than another.As you say, we may find the entombed men more easily this way than any other.""I wonder," said Tom slowly, "if, by any chance, we shall find, through this passage, the lost city we are looking for.""And the idol of gold," added Ned.
"Goosal, do you know anything about this?" asked Professor Bumper."Did you ever hear of another passage leading to the cave where you saw the ancient city?""No, Learned One, though I have heard stories about there being many cities, or parts of a big one, beneath the mountain, and when it was above ground there were many entrances to it.""That settles it!" cried the professor in English, having talked to Goosal in Spanish."We'll try this and see where it leads."They entered the stone-lined passage.In spite of the fact that it had probably been buried and concealed from light and air for centuries, as evidenced by the growth of the giant trees above it, the air was fresh.
"And this is one reason," said Tom, in commenting on this fact, "why I believe it leads to some vast cavern which is connected in some fashionwith the outer air.Well, perhaps we shall soon make a discovery."Eagerly and anxiously the little party pressed forward by the light of the pocket electric lamps.They were obsessed by two thoughts--what they might find and the necessity for aiding in the rescue of their rivals.
On and on they went, the darkness illuminated only by the torches they carried.But they noticed that the air was still fresh, and that a gentle wind blew toward them.The passage was undoubtedly artificial, a tunnel made by the hands of men now long crumbled into dust.It had a slightly upward slope, and this, Professor Bumper said, indicated that it was bored upward and perhaps into the very heart of the mountain somewhere in the interior of which was the Beecher party.
Just how far they went they did not know, but it must have been more than two miles.Yet they did not tire, for the way was smooth.
Suddenly Tom, who, with Professor Bumper, was in the lead, uttered a cry, as he held his torch above his head and flashed it about in a circle.
"We're blocked!" he exclaimed."We're up against a stone wall!"It was but too true.Confronting them, and extending from side to side across the passage and from roof to floor, was a great rough stone.Immense and solid it seemed when they pushed on it in vain.
"Nothing short of dynamite will move that," said Ned in despair."This is a blind lead.We'll have to go back.""But there must be something on the other side of that stone," cried Tom."See, it is pierced with holes, and through them comes a current of air.If we could only move the stone!""I believe it is an ancient door," remarked Professor Bumper.
Eagerly and frantically they tried to move it by their combined weight.The stone did not give the fraction of the breadth of a hair.
"We'll have to go back and get some of your big tunnel blasting powder, Tom," suggested Ned.
As he spoke old Goosal glided forward.He had remained behind them in the passage while they were trying to move the rock.Now he said something in Spanish.
"What does he mean?" asked Ned.
"He asks that he be allowed to try," translated Professor Bumper.
"Sometimes, he says, there is a secret way of opening stone doors in these underground caves.Let him try."Goosal seemed to be running his fingers lightly over the outer edge of the door.He was muttering to himself in his Indian tongue.
Suddenly he uttered an exclamation, and, as he did so, there was a noise from the door itself.It was a grinding, scraping sound, a rumble as though rocks were being rolled one against the other.
Then the astonished eyes of the adventurers saw the great stone door revolve on its axis and swing to one side, leaving a passage open through which they could pass.Goosal had discovered the hidden mechanism.
What lay before them?
