return. It is terrible to think all that treasure may be
lost--lost forever!"

"Who is Alwin Bushnell?"

"My partner--the one who was with me when I found the palace."

"Where is he now?"

"Heaven knows! He went for another balloon."

"Another balloon?"

"Yes; it was with the aid of a balloon that we reached the Silver
Palace. Without it we could not have crossed the gulf."

"Absurd!" muttered the professor.

Despite the fact that the word was merely murmured, the miserable man on
the bed of grass did not fail to catch it.

"Oh, I will convince even you!" he exclaimed, gasping for breath, and
continuing to fumble beneath the straw. "You shall see--you shall know!
But our balloon--we had no means of obtaining a further supply of gas.
It was barely sufficient to take us across the gulf, with a few pieces
of treasure. We struck against the side of the bluff--we were falling
back into the abyss! Barely were we able to scramble out of the car and
cling to the rocks. Then we saw the balloon rise a little, like a bird
freed of burden; but it suddenly collapsed, fluttered downward, and the
mists leaped up and clutched it like a thousand exulting demons,
dragging it down from our sight. We crawled up from the rocks, but it
was a close call--a close call."

He lay exhausted, his eyes closed, his hand ceasing to fumble beneath
the straw. Once more Professor Scotch gave him a little of the brandy.

Frank Merriwell was more than interested; he could feel his heart
trembling with excitement. Something seemed to tell him that this man
was speaking the truth, and he was eager to hear more.

For a long time the unfortunate lay gasping painfully for breath, but,
at last, he was easier. He opened his eyes, and saw Frank watching him
steadily, with an anxious expression.

"Ah!" he murmured, exultantly, "you believe me--you do not doubt! I must
tell you everything. You shall be Jack Burk's heir. Think of it--heir to
wealth enough to make you richer than Monte Cristo! Witness--witness
that I make this boy my heir!"

He turned to the professor and Hans, and both bowed, the former saying:

"We are witnesses."

"Good! We escaped with our lives, but we brought little of the treasure
with us. I was determined to find the way back there, and I made a map.
See, here it is."

He thrust a soiled and crumpled piece of paper into Frank's hand, and
the boy saw there were lines and writing on it.

"How we found our way out of the