new student, who seemed disposed to take life as easily as possible.

"May I speak?" asked Jack, of Dr. Mead.

"Since you are the accused it is but fair that you be given a chance
to clear yourself," was the reply. "But as you have given a certain
publicity to this matter, I shall tell these other students what it
is all about."

Dr. Mead then explained the charge against Jack. There was an uneasy
movement among the other boys, and Adrian Bagot was seen to shift
about. He even started to walk around as though to leave the room,
but the monitor stood at the door and Adrian did not want to make any
confusion by forcing past him. So young Bagot remained in the
laboratory.

"When Professor Grimm accused me of playing this trick I denied it,
as I am innocent," Jack said, when Dr. Mead had finished and looked
at him as if inviting him to speak. "Perhaps if the matter has been
made public the fellows who took the bell would have come forward and
admitted it. As it is I asked twenty-four hours to prove that I did
not do it. I believe I have succeeded.

"In the first place," Jack went on, "I wish to exhibit this garment,"
and he held up to view a long linen coat, commonly called a duster.
"You will observe," he went on, "that there are several brown lines
on it. I have measured these and they are exactly the shape and size
that would be made by the sharp rim of a bell, if it was rested on
the garment when some one was wearing it."