"Thermit," he replied laconically.

"Thermit?" I repeated.

"Yes--a compound of iron oxide and powdered aluminum invented by a
chemist at Essen, Germany. It gives a temperature of over five
thousand degrees. It will eat its way through the strongest
steel."

Jennings, his mouth wide open with wonder, advanced to take the
bust from Kennedy.

"No--don't touch it," he waved him off, laying the bust on the
desk. "I want no one to touch it--don't you see how careful I was
to use the tongs that there might be no question about any clue
this fellow may have left on the marble?"

As he spoke, Craig was dusting over the surface of the bust with
some black powder.

"Look!" exclaimed Craig suddenly.

We bent over. The black powder had in fact brought out strongly
some peculiar, more or less regular, black smudges.

"Finger prints!" I cried excitedly.

"Yes," nodded Kennedy, studying them closely. "A clue--perhaps."