"Yes, an invention of a chemist named Goldschmidt, of Essen,
Germany. It is a compound of iron oxide, such as comes off a
blacksmith's anvil or the rolls of a rolling-mill, and powdered
metallic aluminum. You could thrust a red-hot bar into it without
setting it off, but when you light a little magnesium powder and
drop it on thermit, a combustion is started that quickly reaches
fifty-four hundred degrees Fahrenheit. It has the peculiar
property of concentrating its heat to the immediate spot on which
it is placed. It is one of the most powerful oxidising agents
known, and it doesn't even melt the rest of the steel surface.
You see how it ate its way through the steel. Either black or red
thermit will do the trick equally well."

No one said anything. There was nothing to say.

"Someone uncommonly clever, or instructed by someone uncommonly
clever, must have done that job," added Craig. "Well, there is
nothing more to be done here," he added, after a cursory look
about the office. "Mr. Andrews, may I have a word with you? Come
on, Jameson. Good day, Mr. Kahan. Good day, Officer."

Outside we stopped for a moment at the door of Andrews's car.

"I shall want to see Mr. Morowitch's papers at home," said Craig,
"and also to call on Doctor Thornton. Do you think I shall have
any difficulty?"

"Not at all," replied Mr. Andrews, "not at all. I will go with
you myself and see that you have none. Say, Professor Kennedy,"