y. I cover the pistol with a cloth. I defy anyone in this room
to tell me the exact moment when I discharged the pistol. I could have
shot any of you, and an outsider not in the secret would never have
thought that I was the culprit. To a certain extent I have reproduced
the conditions under which this shooting occurred.

"At once on being sure of this feature of the case I despatched a man
to Hartford to see this inventor. The man obtained from him a complete
list of all the dealers in New York to whom such devices had been
sold. The man also traced every sale of those dealers. He did not
actually obtain the weapon, but if he is working on schedule-time
according to agreement he is at this moment armed with a
search-warrant and is ransacking every possible place where the person
suspected of this crime could have concealed his weapon. For, one of
the persons intimately connected with this case purchased not long ago
a silencer for a thirty-two-calibre revolver, and I presume that that
person carried the gun and the silencer at the time of the murder of
Kerr Parker."

Kennedy concluded in triumph, his voice high pitched, his eyes
flashing. Yet to all outward appearance not a heart-beat
was quickened. Someone in that room had an amazing store of
self-possession. The fear flitted across my mind that even at the last
Kennedy was baffled.

"I had anticipated some such anti-climax," he continued after a
moment. "I am prepared for it."

He touched a bell, and the door to the next room opened. One of
Kennedy's graduate students stepped in.

"You have the records, Whiting?" he asked.

"Yes, Professor."

"I may say," said Kennedy, "that each of your chairs is wired under
the arm in such a way as to betray on an appropriate indicator in the
next room every sudden and undue emotion. Though it may be concealed
from the eye, even of one like me who stand facing you, such emotion
is nevertheless expressed by physical pressure on the arms of
the chair. It is a test that is used frequently with students to
demonstrate various points of psychology. You needn't raise your arms
from the chair, ladies and gentlemen. The tests are _all over_ now.
What did they show, Whiting?"

The student read what he had been noting in the next room. At the
production of the coat during the demonstration of the markings of the
bullet, Mrs. Parker had betrayed great emotion, Mr. Bruce had done
likewise, and nothing more than ordinary emotion had