y here for more than a few days. My work is done: I am ready to
start. In fact, I would have started yesterday instead of to-day, had
you arrived. Now don't ask any questions; it's nearly lunch time."

"What's the story, Doctor?" I asked after lunch as I puffed one of his
excellent cigars. "And why did you pick me to tell it to?"

"For several reasons," he replied, ignoring my first question. "In the
first place, I like you and I think that you can keep your mouth shut
until you are told to open it. In the second place, I have always found
that you had the gift of vision or imagination and have the ability to
believe. In the third place, you are the only man I know who had the
literary ability to write up a good story and at the same time has the
scientific background to grasp what it is all about. Understand that
unless I have your promise not to write this story until I tell you that
you can, not a word will I tell you."

I reflected for a moment. The _Graphic_ would expect the story when I
got back, but on the other hand I knew that unless I gave the desired
promise, the Doctor wouldn't talk.

"All right," I assented, "I'll promise."

"Good!" he replied. "In that case, I'll tell you all about it. No doubt
you, like the rest of the world, think that I'm crazy?"

"Why, not at all," I stammered. In point of fact, I had often harbored
such a suspicion.

"Oh, that's all right," he went on cheerfully. "I _am_ crazy, crazy as a
loon, which, by the way, is a highly sensible bird with a well balanced
mentality. There is no doubt that I am crazy, but my craziness is not of
the usual type. Mine is the insanity of genius."

* * * * *

He looked at me sharply as he spoke, but long sessions at poker in the
San Francisco Press Club had taught me how to control my facial muscles,
and I never batted an eye. He seemed satisfied, and went on.

"From your college work you are familiar with the laws of magnetism," he
said. "Perhaps, considering just what your college career really was, I
might better say that you are supposed to be familiar with them."

I joined with him in his laughter.

"It won't require a very deep knowledge to follow the thread of my
argument," he went on. "You know, of course, that the force of magnetic
attraction is inversely proportional to the square of the distances
separating the magnet and the attracted particles, and also that each
magnetized particle had two poles,