th uplifted hand. "The thing I have to reveal is of such
paramount importance that I must not be interrupted. You must bear with
me while I go back some months and even years in time to make myself
understood.

"You all remember the mysterious disappearance of Professor Reubens.
Yes, I see that you do. It caused a sensation. He was the foremost
scientist in the country--it would not be exaggerating too much to say
in the world. His name was not as well known among the masses as that
of Miller and Dean; in fact, outside of an exclusive circle it wasn't
known at all, but ask any scientist about Reubens. He was a tall, dour
man of sixty, with Scotch blood in his veins, and was content to teach
a class in a college because of the leisure it afforded him for his own
research work. That was at the University of Arizona in Tucson.

"The faculty of the college was proud to have him on its staff and
provided him with a wooden building back of the campus, for a private
laboratory and workshop. I understand that the Rockefeller Institute
contributed funds towards Professor Reubens' experiments, but I am not
certain.

"At any rate he had a wonderfully well equipped place. I was a pupil at
the University and attended his class in physics. A strong friendship
grew up between us. How can I explain that friendship? I was not a
particularly brilliant student, but he had few friends and perhaps my
boyish admiration pleased him. I think, too, that he was lonely,
heart-hungry for affection. His wife was dead, and his own boy.... But
I won't go into that.

"Suffice it to say that I believe he bestowed on me some of the
affection he had felt for his dead son. Indeed I am sure he did. Be
that as it may, I often visited him in his laboratory and watched,
fascinated, as he pored over some of his intricate apparatus. In a
vague way, I knew that he was seeking to delve more deeply into the
atom.

"'Before Leeuwenhoek invented the microscope,' the Professor once said,
'who ever dreamed of the life in a drop of water? What is needed now is
a super-microscope to view the atom.'

"The idea thrilled me.

"'Do you believe, sir, that an instrument will ever be invented that
will do that?'

"'Yes. Why not? I am working on some such device myself. Of course the
whole thing has to be radically different. The present, method of
deducing the atom by indirection is very unsatisfactory. We can know
nothing for certain until direct observation is p