This was the plan which the Camera Chap had suggested to Lawyer Hands, and which had earned the attorney’s enthusiastic approval.

Hawley had reasoned that in all probability the clockwork used in the construction of the infernal machine had been purchased by the younger Gale. He had reasoned, also, that Gale would not be so careless as to purchase the clock in Oldham, but would take the precaution of going out of town for it. His scheme was to visit every nearby town in the hope of striking the store at which the purchase had been made.

It was a long and tedious task, and he realized that there was a good chance that he would have all his trouble for nothing; but Hawley resolutely stuck to it, and, after several days of discouragement, he met with success.

In a town called Roxbury, thirty-five miles from Oldham, he found a jeweler who positively identified the snapshot which the Camera Chap showed him as the photograph of a man who had bought a cheap alarm clock there a few days before.

The jeweler’s wife and clerk also remembered Gale very well. Both of them had been present when the sale of the alarm clock was made, and were positive that the customer was the young man in the picture.

Highly elated with his success, the Camera Chap was about to return to Oldham to tell the good news to Lawyer Hands, when, quite unexpectedly, he made another very important discovery.

A block from the jewelry store some workmen were engaged in excavating for the foundation of a building. As Hawley passed this spot, he noticed that the men were blasting some rock with dynamite.

An inspiration came to him. Was it not possible, he thought, that Gale, too, had passed by this place, and, seeing the blasting going on, had tried to obtain from the workmen the explosive needed for the infernal machine?

There was only the merest chance, of course, that such was the case; but he was not in the habit of overlooking mere chances. He decided that this “hunch” was well worth investigating.

Stepping up to the foreman of the gang of workmen, he once more produced his snapshot, and showed it to the man.