“I also discovered that the typewriter recently purchased by Mr. Copperdock was a Planet, and I took a careful note of the brand of pen and red ink he habitually used. I next made enquiries among the envelope addressing agencies, until I found one which employed Planet machines. To this agency I sent my envelopes, together with a telephone directory in which I had marked some two thousand names, among which were those of my intended victims who happened to have a telephone. To this list I added one of my own, containing a thousand additional names, among them the jurymen I had not found in the telephone book. I instructed the agency to type these names and addresses on the envelopes. It was a safe assumption that a year later, when I began operations, the agency would not remember having typed the names of the dead men among so many thousands of others. The counters I numbered myself, as required.