Craig laid the piece of steel on the dynamometer in the position it had occupied in the safe, and braced it tightly.  Then he took a jimmy and pressed on it with all his strength.  The steel door was connected with the indicator, and the needle spun around until it indicated a pressure such as only a strong man could have exerted.  Comparing the marks made in the steel in the experiment and by the safe-cracker, it was evident that no such pressure had been necessary.  Apparently the lock on the door was only a trifling affair, and the steel itself was not very, tough.  The safe-makers had relied on the first line of defence to repel attack.

Craig tried again and again, each time using less force.  At last he got a mark just about similar to the original marks on the steel.

“Well, well, what do you think of that?” he exclaimed reflectively.  “A child could have done that part of the job.”

Just then the lights went off for the night.  Craig lighted the oil-lamp, and sat in silence until the electric light plant foreman appeared with; the card-record, which showed a curve practically identical with that of the night before.

A few moments later Professor Fletcher’s machine came up the driveway, and he joined us with a worried and preoccupied look on his face that he could not conceal.  “She’s terribly broken up by the suddenness of it all,” he murmured as he sank into an armchair.  “The shock has been too much for her.  In fact, I hadn’t the heart to tell her anything about the robbery, poor girl.”  Then in a moment he asked, “Any more clues yet, Kennedy?”

“Well, nothing of first importance.  I have only been trying to reconstruct the story of the robbery so that I can reason out a motive and a few details; then when the real clues come along we won’t have so much ground to cover.  The cracksman was certainly clever.  He used an electric drill to break the combination and ran it by the electric light current.”

“Whew!” exclaimed the professor, “is that so?  He must have been above the average.  That’s interesting.”

“By the way, Fletcher,” said Kennedy, “I wish you would introduce me to your fiancee to-morrow.  I would like to know her.”

“Gladly,” Fletcher replied, “only you must be careful what you talk about.  Remember, the death of uncle has been quite a shock to her—­he was her only relative besides myself.”

“I will,” promised Kennedy, “and by the way, she may think it strange that I’m out here at a time like this.  Perhaps you had better tell her I’m a nerve specialist or something of that sort—­ anything not to connect me with the robbery, which you say you haven’t told her about.”

The next morning found Kennedy out bright and early, for he had not had a very good chance to do anything during the night except reconstruct the details.  He was now down by the back gate with his camera, where I found him turning it end-down and photographing the road.  Together we made a thorough search of the woods and the road about the gate, but could discover absolutely nothing.