This brought blood, and he grew more enraged than ever.

Like an eel Leo squirmed from his grasp, and panting the two faced each other.

"I'll fix you!" howled Porler.

He ran to his trunk to get a weapon, for he was in his balloon costume, but suddenly stopped short.

"Where is he?"

He referred to Mart Keene, who had disappeared.

Fearful that the boy was running away, Porler forgot all about Leo for the time being and ran outside.

The young gymnast ran to his own tent and came out.

He saw Porler looking around anxiously.

The lad had certainly escaped.

"I hope he doesn't find him," thought Leo.

Porler whispered to his a.s.sistant, a man named Murphy, and the latter hurried off to ascertain, if possible, what had become of Mart.

Then Porler re-entered his tent. The band was playing and it was time for him to make his ascension.

He delayed as long as possible, but at last the crowd got impatient.

"A little hole in the balloon, that is all, gentlemen," said Porler. "I am ready now."

He did not dare to speak of Mart for fear an investigation would be started.

He came out, smiling falsely at the crowd, and walked over to where his balloon swayed in the air.

At a given signal the balloon shot up with Porler in the basket.

When the balloon was scarcely two hundred feet in the air Porler got out his parachute and leaped overboard.

As he came floating down he made several turns about the double handle of the parachute.

The crowd applauded this, for it was something new to them.

Leo saw the exhibition from a hole in the top of his tent, and smiled to himself.

"There are twenty balloonists in the United States who can do as good as that, and better," he thought.

Porler had expected to make Mart go up with him.

The boy was to leave the balloon with him on the parachute, and then, when within fifty feet of the ground, fly away by himself on an immense pair of white wings filled with gas.

The band continued to play after Porler landed.

"Now for the circus balloonist!" was the cry.

A flourish from the band and Leo came running out.

He was dressed in a suit of white and gold. The gold sparkled in the sunshine and made a beautiful appearance, quite in contrast to Porler's dirty costume of plain white and red.

"Let go!"

Up shot the circus balloon with a rush.

There was Leo, not in a basket, but clinging to a slender trapeze. A shout of approval arose.

Up and up went the balloon until it became to the human eye about as large as a dinner plate.

The young gymnast was making a great ascension.

As he went up he began to perform on the trapeze. He turned over and over and hung by his toes.

The crowd could scarcely believe its eyes. Porler was completely outdone.

At last both balloon and balloonist pa.s.sed out of sight of those on the fair grounds.

Leo landed in a field several miles from the city.

He hired the farmers who came out to see what was the matter to help him pack up the balloon.

About an hour later Greson came along and the outfit was packed on a wagon and carted back to the circus grounds. When Leo came in for supper he found a note awaiting him.

It was from Mart Keene and ran like this:

"_Dear Mr. Dunbar_: I must thank you for your bravery and great kindness to me. I am alone in the world and need a friend. If you will help me, kindly call at the address given on the inclosed card."

The young gymnast looked at the card. It bore the address of a boarding-house on a side avenue half a dozen blocks from the grounds.

He at once departed for the place.

CHAPTER x.x.x.-MART KEENE'S STORY.

It did not take Leo long to reach the boarding-house advertised on the card.

"I wish to see Mart Keene," he said to the lady who answered his summons.

"Oh, yes; please walk into the parlor."