g wolfram with soda
ash, and wolfram is a native tungstate of iron and manganese. This soda
preparation is used commercially in making garments fire-proof, and Joe
had learned this from Mr. Herbert Waldon, the chemist. He had decided to
use this instead of an alum solution, which is credited with great
fire-resisting qualities. It has them, too, to a certain extent, but by
experimenting Joe had found the tungstate of soda best.

It was the evening of the circus in the city in which the show was to
remain two days. Ham Logan had returned to Joe after having eaten a good
meal, and later Bill Watson formed the third member of a trio that
talked for some time in a corner of Joe's tent.

As already said, it was the evening performance, and as Helen finished
her act on Rosebud she looked over toward the place where Joe was
preparing to do his slide down the slanting wire.

"I wonder what he had in mind as a new act for me," mused Helen. "I do
hope it isn't anything to do with fire. That sort of stunt creates a
sensation, but it's dangerous, in spite of what Joe does to himself. I
don't like it! Not after what happened to Joe that day!"

She had seen that Rosebud was given in charge of the groom who always
looked after the clever steed, and now Helen moved over where she could
watch Joe's comparatively new wire act.

As she approached this part of the circus tent Helen was startled to see
several men carrying large hoops on long poles, take their positions on
either side of the slanting wire down which the daring performer was
soon to slide on his head, by means of the wheeled cap.

"That's something new!" exclaimed Helen, as she saw the men with the big
hoops. "I wonder if Joe is going to jump through them, as I jump through
the paper hoops from Rosebud's back?"

Joe was up on the little platform now, having finished his wire act. He
was adjusting to his head the leather cap.

"Ladies and gentlemen!" began Jim Tracy in his sonorous voice, as he
pointed to Joe on his high perch, thus calling attention to the
performer.

All eyes were turned in his direction. Then, as Joe stooped over and
stood on his head, preparatory to sliding down the wire, the hoops,
which the men held over the cable by means of long poles, suddenly burst
into flame. Held over the wire, down which Joe would in a moment slide,
was a row of fiery circles!

Helen held her hand over her lips to stifle a scream.

CHAPTER XVII

THE BROKEN BO