He pointed dramatically to Joe, who stood up straight, ready to do his act.

“Are you ready?” asked the man who was to release the trapeze, which was caught up at one side of the platform opposite Joe.

“Ready,” answered the young acrobat.

The man pulled a rope which released a catch, letting the trapeze start on its long swaying swing.  The man pulled it by means of a long, thin cord, until it was making big arcs, like some gigantic pendulum.

Joe watched it carefully, judging it to the fraction of an inch.  He stood poised and tense on the gayly decorated platform, himself a fine picture of physical young manhood.  The band was blaring out the latest Jazz melody.

Suddenly, from his perch, the young acrobat gave a cry, and Jim Tracy, on the ground below, hearing it, held up his white-gloved hand as a signal for the music to cease.

Then Joe leaped.  Full and fair he leaped out toward the swinging bar of the big trapeze, the snare drum throbbing out as he jumped.  He was dimly conscious of thousands of eyes watching him—­eyes that looked curiously and apprehensively up.  And he realized that Helen was also watching him.

As true as a die, Joe’s hands caught and gripped the bar of the swinging trapeze.  So far he was safe.  The momentum of his jump carried him in a long swing, and he at once began to undulate himself to increase his swing.  He must do this in order to get to the second platform.

As the young performer began to do this, he looked up at the wire ropes of his trapeze.

It was a look given instinctively and for no particular purpose, as Joe’s eyes must rest, most of all, on the second platform where he needed to land, to save himself from a bad fall.

As his eyes glanced along the steel cables on which his life depended, he saw, to his horror, a spot of rust on one.  And at the spot of rust several of the thin strands of twisted wire were loose and frayed.

The cable seemed about to give way!

CHAPTER V

A FIRE SENSATION

Joe Strong had to think quickly.  Every acrobat, every person who does “stunts” in a circus, must; for something is always happening, or on the verge of taking place.  And when Joe looked up and saw the rusted wire and noted the fraying strands, several thoughts shot through his mind at once.

“That rust spot wasn’t there this morning when, I looked at the trapeze,” he mused.  “And it hasn’t rained since.  How did it get there?”

He thought of the too talkative Harry Loper, and an ugly suspicion associated itself with him.  But Joe had no time for such thoughts then.  What was vital for him to know was whether or not the thin wire cable would remain unbroken long enough for him to reach the maximum of his swing, and land on the platform.  Or would he fall, spoiling the act and also endangering himself?