Ham Logan. "It will eat right through your
shoes. Glass is the only thing it won't hurt--glass and porcelain. They
mix it in porcelain retorts. I'll throw some loose earth over this
place. The effects of the acid will soon be lost, but while it's active
it's terrible stuff, believe me!"

"And you say you found that bottle in my baggage?" asked Joe.

"Yes," answered Ham Logan. "And am I right in saying you didn't know it
was there?"

"I certainly didn't," declared Joe. "Who in the world could have put it
there?"

"Have you any enemies?" asked Ham. "I mean some one who would like to
see your circus acts spoiled, or even see you laid up for a while?"

"Well, I guess perhaps there are some I've made enemies of by having to
discharge them, or something like that," admitted Joe, his thoughts
going naturally to Bill Carfax. "There's one man, but he hasn't been
seen around for a good while."

"That doesn't count. He may have gotten some one to do his trick for
him," asserted Ham. "You'd better look out, Mr. Strong."

"I will!" declared Joe. "And thank you for your watchfulness. As you
say, I didn't know that bottle was there, and I might have broken it by
accident or have opened it and spilled some out. How did you come to
discover it?"

"Just by accident. The smell is something you never forget. It comes up
even around the glass stopper. As soon as I began overhauling your
things, as you told me to, I smelled the stuff and I went on a still
hunt for it.

"I was careful, too. I knew what it meant to get any of that acid on
you, or on any of the things about you. I used to work in the chemical
plant where they made the stuff--that was after I left the circus. Well,
it can't do any harm now," he said as he got a shovel and covered with
clean earth the bits of broken glass and the still fuming drops of add.

"Thank you," said Joe fervently.

He went into his private tent. Presently he came out with a bit of wire
cable, such as is used in making circus trapezes. One end was blackened
and partly fused, as though it had been in the fire. Joe held out this
bit of wire rope. It was part of the trapeze he used in his big swing.

"What would you say had eaten through these strands?" he asked.

Ham Logan looked carefully at the cable. He sniffed it cautiously. He
held it up to the light and again smelled it.

"It was this same acid that ate those strands," he declared. "I know how
it used to eat metal out at the chemical