"For some time before Mr. Marks's unfortunate death," he said slowly, "you had been experimenting with a new explosive."
I nodded my head. I had no idea how he had got his information, for as far as I was aware George was the only person who had any knowledge of my secret.
"And I believe you were just on the point of success when you were arrested?"
"Theoretically I was," I said. "These matters don't always work out quite so well when you put them to a practical test."
"Still, you yourself were quite satisfied with the prospects?"
I nodded again.
"And unless I am wrong, this new explosive will be immensely more powerful than anything now in use?"
"Immensely," I repeated; "in fact, there would be no practical comparison between them."
"Can you give me any idea as to its strength?"
I hesitated. "According to my calculations," I said slowly, "it ought to prove at least twenty times as powerful as gun-cotton."