"But Doctor," he said, "can you reckon on your match so exactly that you can be quite sure it will fire the mine at the right moment?"
"I don't need to reckon at all; that's a difficulty easily got over."
"Then you have a match a hundred feet long?"
"No."
"You are simply going to lay a train of powder."
"No, that might miss fire."
"Well, there is no way then but for one of us to devote his life to the others, and go and light the powder himself."
"I'm ready," said Johnson, eagerly, "ready and willing."
"Quite useless my brave fellow," replied the Doctor, holding out his hand. "All our lives are precious, and they will be all spared, thank God!"
"Well, I give it up!" said the American. "I'll make no more guesses."