ink they was makin' fun of us. I kinder thought one of 'em called
out somethin' that sounded like, 'Help us!'" went on Joe breathlessly.

"Talk to me about your mysteries! Who ever ran up against a worse one
than this?" gasped Jerry, scratching his head, as he shivered in the
cool air.

"What time is it, anyhow?" demanded Will, who had now found his camera,
and was feeling satisfied, because it did not appear to have sustained
any injury.

"Time? I declare if that isn't dawn in the east, fellows! Time we were
up, I guess," remarked Frank, stooping over again, determined to learn
the secret of the sudden and violent collapse of the tent, accompanied by
such strange whispering voices that seemed to die away in the distance.

"Well, all I can say is that if dawn comes with such a swoop down in this
blessed country, it's me back to my native heath again," grumbled Jerry,
who had received a few bruises in the mix-up. Up to now he had paid no
attention to them, but they were beginning to make themselves manifest.

"What's this?"

Frank uttered the cry as he bent over and stared at something which he
had discovered under the canvas.

"Hold on! I've got my gun handy!" exclaimed Bluff, thinking that if it
were a wild animal his time had come to distinguish himself.

"Oh! What is it?" echoed Will, crowding near.

The fire was now leaping madly up as the tinder-like dried palmetto
leaves and stalks caught, so that every one could easily see.

"Why, it's a bag!--a big bean bag!" exclaimed Will, in amazement. "Where,
in the name of goodness, did that come from, fellows?"

"A bean bag! Tell me about that, will you?" said Jerry. And then, as he
bent over to clutch hold of it, he went on: "Why, as sure as you live,
it's a _sand bag_! Who ever could have shied that thing at us and then
run away?"

Frank was more than startled. He had seen just such bags before, and
filled with sand, too. He knew to what uses they were put.

"Say! What do you think, that bag is ballast from a balloon or airship?"
he cried.

"Ballast!"

"From an airship!"

The four outdoor chums stood there and stared, first at each other and
then at the suspicious bag that lay there on the canvas. There could be
no mistake about its contents, for one seam had broken, and the sand was
trickling out even now.

"Then a balloon passed over us in the night, and they threw out a sand
bag to lighten her! What do you think of that?" gasped Jerry, as if
hard