terra firma. As he rode off, Dick burst
into shouts of laughter. His little joke had certainly turned out to
be better than he expected and for many days after that he had only to
slyly introduce some talk about a lion to cause the professor to look
at him in a very quizzical way.

CHAPTER XXVIII.

THE UPPER REGIONS.

The boys were up with the sun the next day. It was the morning which
was to witness the start of the flight for Rattlesnake Island.
Everything about the Wondership was in readiness for the enterprise,
and there only remained the tin breakfast utensils and the tents to be
packed when they had concluded the morning meal.

Naturally excitement ran high. The hunt for the island, too, might be
a long one. But they felt that ultimately they would find it, that it
would not be like the three buttes of Peg-leg Smith.

When everything was declared ready, Jack opened the charging-tube of
the gas reservoir and poured in some of the volatile powder that made
the lifting vapor. In fifteen minutes the gauge showed a good
pressure in the tank and the valve was turned.

In the hot sun the balloon bag expanded quickly. At length the bag was
almost full.

"Everything ready?" cried Jack, at length, when all were on board.

"Ready," said Tom at the engines.

"Then off we go!"

Tom pulled the clutch lever and the propellers whirled. Jack gave the
steering and controlling wheel an impulse and like a huge bird the
Wondership shot up. But she rose slowly, for besides the unusual
number of passengers, she was also carrying a great weight in
supplies.

As the craft rose three figures watched it from under the concealment
of a clump of mesquite.

"There they go, boys," said Masterson, for it was he and his two
cronies.

"Yes, they're off for Rattlesnake Island," sneered Eph. "I hope they
get bitten."

"I'll bet they don't dream that we know everything about their
plans," chuckled Sam. "I'd like to get even with that red-headed kid."

"Well, you'll get a chance before long," declared Bill Masterson. "I
don't see that there's any use in hanging around here any longer," he
went on. "The thing to do now is to get our boats and go down the
river."

"Won't they be astonished when they see us," said Eph.

"Maybe they'll try to chase us away. They outnumber us," said the
timid Sam.

"They'd better not," vaunted Bill Masterson. "I guess we've got as
good a right to that old island as they have."

"That's r