dictaphone speaking—not the man.”

 

“And the murderer switched it on. Then he must have been in the room at that

minute?”

 

“Possibly. But we must not exclude the likelihood of some mechanical device

having been applied—something after the nature of a time lock, or even of a

simple alarm clock. But in that case we must add two qualifications to our

imaginary portrait of the murderer. It must be some one who knew of Mr.

Ackroyd’s purchase of the dictaphone and also some one with the necessary

mechanical knowledge.

 

“I had got thus far in my own mind when we came to the footprints on the window

ledge. Here there were three conclusions open to me. (1) They might really have

been made by Ralph Paton. He had been at Fernly that night, and might have

climbed into the study and found his uncle dead there. That was one hypothesis.

(2) There was the possibility that the footmarks might have been made by

somebody else who happened to have the same kind of studs in his shoes. But the

inmates of the house had shoes soled with crepe rubber, and I declined to

believe in the coincidence of some one from outside having the same kind of

shoes as Ralph Paton wore. Charles Kent, as we know from the barmaid of the Dog

and Whistle, had on a pair of boots ‘clean dropping off him.’ (3) Those prints

were made by some one deliberately trying to throw suspicion on Ralph Paton. To

test this last conclusion, it was necessary to ascertain certain facts. One pair

of Ralph’s shoes had been obtained from the Three Boars by the police. Neither