r backs ached. They would not give up,
however. The lure of treasure had them in its grasp and they were
determined to find out just what the contents of this chest were if such
a thing were possible.

"Just a little more," urged Grant, and with one final effort the chest
was pushed out onto the ledge of rock in front of the cave.

For a few moments the boys were too exhausted to do more than stand
around puffing and gasping for breath. Such a task, combined with the
heat of the tropics, would tax the strength and endurance of the
hardiest.

"Now let's open it up," exclaimed Fred. "Where's the top?"

"It's over on its side," said Grant. "Here's the top and it's
padlocked."

"So it is," said Fred disappointedly. "What can we do?"

"Get a rock," directed Grant. "It's pretty well rusted and by hammering
it we may be able to break it."

A suitable rock was quickly found and an attack begun on the padlock.
Grant pounded away for dear life, while the others stood around and
watched him. After a few moments he stopped to inspect the result of his
efforts.

"Think you can do it?" inquired John.

"I don't know," said Grant. "I think I made a little impression on it,
but it'll take some time."

"Well, I'm going back into the cave," announced John. "I'm going to
inspect that patch of light back there. When you get the box open, yell
at me."

He disappeared in the dusk of the cave while his three companions took
turns at hammering the lock. It was stubborn, but was beginning to show
some signs of yielding and the boys stuck manfully to their task. They
seemed to be on the verge of succeeding when a great commotion inside
the cave suddenly arrested their attention.

A moment later John burst forth. His face was ashen and his eyes bulged
wide with fear. His hands shook as if he had the ague and his breath was
almost gone.

"What is it, John?" demanded Grant in alarm, while Fred and George also
crowded around the frightened boy. He had evidently received a terrible
shock of some kind and his three companions were greatly affected by his
appearance.

"What's the matter?" exclaimed Grant anxiously, but all that John could
do was to mumble incoherently and point towards the interior of the
cave.

CHAPTER XIV

AN ODD DISCOVERY

"John!" begged Grant. "Tell us what's the matter."

John, however, was in no condition to say anything. He shivered and
shook, and kept glancing fearfully at the entrance to the ca