wide, and how deep they could only guess. Swiftly it flowed on, its
roar filling the tunnel.

CHAPTER XX

THE CITY OF GOLD

"Well, I guess this is the end of it," remarked Ned ruefully, as
they stood contemplating the roaring stream by the gleam of their
electric flash lamps. "We can't go on to the city of gold unless we
swim that river, and--"

"And none of us is going to try that!" interrupted Tom sharply. "The
strongest swimmer in the world couldn't make a yard against that
current. He'd be carried down, no one knows where."

"Bless my bathing suit, yes!" exclaimed Mr. Damon. "But what are we
to do? Can't we make a raft, or get a boat, or something like that?"

"Hab t' be a mighty pow'ful boat t' git across dat ribber ob
Jordan," spoke Eradicate solemnly.

"That's right," agreed Ned. "But say, Tom, don't you think we could
go back, get a lot of trees, wood and stuff and make some sort of a
bridge? It isn't so very wide--not more than thirty or forty feet.
We ought to be able to bridge it."

"I'm afraid not," and Tom shook his head. "In the first place any
trees that would be long enough are away at the far edge of the big
plain, and we'd have a hard job getting them to the temple, to say
nothing of lugging them down the tunnel. Then, too, we don't know
much about building a bridge, and with no one on the other side to
help us, we'd have our hands full. One slip and we might be all
drowned. No, I guess we've got to go back," and Tom spoke
regretfully. "It's hard luck, but we've got to give up and go back."

"Den I's pow'ful glad I got ma golden image when I did, dat's suah!"
exclaimed Eradicate. "Ef we doan't git no mo' I'll hab one. But I'll
sell it and whack up wid yo' all, Massa Tom."

"You'll do nothing of the sort, Rad!" exclaimed the young inventor.
"That image is yours, and I'm sorry we can't get more of them."

He turned aside, and after another glance at the black underground
river which flowed along so relentlessly he prepared to retrace his
steps along the tunnel.

"Say, look here!" suddenly exclaimed Ned. "I'm not so sure, after
all that we've got to turn back. I think we can go on to the city of
gold, after all."

"How do you mean?" asked Tom quickly. "Do you think we can bring the
balloon down here and float across?"

"Bless my watch chain!" exclaimed Mr. Damon, "but that WOULD be a
way. I wonder--"

"No, I don't mean that way at all," went on Ned. "But it seems to me
as if t