"I don't believe you can tell," said Oliver desperately, "just by holding your hand over it a minute."
"Science is unerring, my young friend," said the old man calmly. "But we waste time. Take off your coat and prepare yourself for the operation."
The crisis had come, the old man approached with his dangerous weapon. Atthis supreme moment Oliver espied a bell-knob. He sprang to it, and rang a peal that echoed through the house, and was distinctly heard even in the chamber where they were standing.
"What did you do that for?" demanded the old man angrily.
"I am not going to stay here to be murdered!" exclaimed Oliver. "I give you warning that I will resist you with all my strength."
"You would foil me, would you?" exclaimed the maniac, now thoroughly excited. "It must not be."
Oliver hurriedly put a chair between himself and the old man.
At that moment steps were heard on the staircase, and someone tried the door.
"Help!" shouted Oliver, encouraged by what he heard.
"What is the matter?" demanded a voice outside. "Father, what are you doing?"