"Such a thing is impossible," declared Dr. Ransome emphatically, in the course of the conversation.
"Nothing is impossible," declared The Thinking Machine with equal emphasis. He always spoke petulantly. "The mind is master of all things. When science fully recognizes that fact a great advance will have been made."
"How about the airship?" asked Dr. Ransome.
"That's not impossible at all," asserted The Thinking Machine. "It will be invented some time. I'd do it myself, but I'm busy."
Dr. Ransome laughed tolerantly.
"I've heard you say such things before," he said. "But they mean nothing. Mind may be master of matter, but it hasn't yet found a way to apply itself. There are some things that can't be thought out of existence, or rather which would not yield to any amount of thinking."
"What, for instance?" demanded The Thinking Machine.
Dr. Ransome was thoughtful for a moment as he smoked.
"Well, say prison walls," he replied. "No man can _think_ himself out of a cell. If he could, there would be no prisoners."
"A man can so apply his brain and ingenuity that he can leave a cell, which is the same thing," snapped The Thinking Machine.