gold!"

As they passed through the stone door, Tom and Professor Bumper tried
to get some idea of the mechanism by which it worked. But they found
this impossible, it being hidden within the stone itself or in the
adjoining walls. But, in order that it might not close of itself and
entomb them, the portal was blocked open with stones found in the
passage.

"It's always well to have a line of retreat open," said Tom. "There's
no telling what may lie beyond us."

For a time there seemed to be nothing more than the same passage along
which they had come. Then the passage suddenly widened, like the large
end of a square funnel. Upward and outward the stone walls swept, and
they saw dimly before them, in the light of their torches, a vast
cavern, seemingly formed by the falling in of mountains, which, in
toppling over, had met overhead in a sort of rough arch, thus
protecting, in a great measure, that which lay beneath them.

Goosal, who had brought with him some of the fiber bark torches, set a
bundle of them aflame. As they flared up, a wondrous sight was
revealed to Tom Swift and his friends.

Stretching out before them, as though they stood at the end of an
elevated street and gazed down on it, was a city--a large city, with
streets, houses, open squares, temples, statues, fountains, dry for
centuries--a buried and forgotten city--a city in ruins--a city of the
dead, now dry as dust, but still a city, or, rather, the strangely
preserved remains of one.

"Look!" whispered Tom. A louder voice just then, would have seemed a
sacrilege. "Look!"

"Is it what we are looking for?" asked Ned in a low voice.

"I believe it is," replied the professor. "It is the lost city of
Kurzon, or one just like it. And now if we can find the idol of gold
our search will be ended--at least the major part of it."

"Where did you expect to find the idol?" asked Tom.

"It should be in the main temple. Come, we will walk in the ancient
streets--streets where no feet but ours have trod in many centuries.
Come!"

In eager silence they pressed on through this newly discovered
wonderland. For it was a wonderful city, or had been. Though much of
it was in ruins, probably caused by an earthquake or an eruption from a
volcano, the central portion, covered as it was by the overtoppling
mountains that formed the arching roof, was well preserved.

There were rude but beautiful stone buildings. There were archways;
temples; pub