"Nothing, except that it was sent by a woman. I was not surprised to learn that. Naturally I should expect that a woman was responsible for these threats. But what woman? That is the question." He sat for a long time, thinking, his eyes fixed upon the floor.
Suddenly there came a ring at the doorbell. Mrs. Morton, without waiting for the maid, sprang to the hall, with Duvall close at her heels. As she threw it open, they saw a man standing in the doorway. Duvall was the first to recognize their caller.
"How do you do, Mr. Baker," he said, holding out his hand.
Mr. Baker came in, and greeted Mrs. Morton.
"I didn't expect to find Mr. Duvall here," he said. "In fact, I came to you to get his hotel address. Luckily I won't need it, now."
"Anything new?" Duvall asked, as they returned to the library.
"Nothing much. I got those samples of the writing of the various typewriters, as you requested," Baker replied, "and I thought that instead of waiting until to-morrow, it would be better to bring them to you to-night." He took a sheaf of papers from his pocket. "There are thirty-two in all. What are you going to do with them?" He placed the papers in Duvall's hand.
The latter sat down at the library table and placed the sheets of paper before him.
"Of course you know," he said to Baker, "that every typewriting machine has its unmistakable peculiarities. It is almost impossible to find a machine that has been used at all, that has not developed certain individual defects, or qualities, found in no other machine. Now let us take for instance the letters that Miss Morton has received during the past few days. They have all been written on the same machine, and I am of the opinion that it is a fairly old one. While going down to the studio this afternoon, I worked out and wrote down in my notebook the particular features which appear in all these letters." He took a small leather-covered book from his pocket.
"In the first place," he said, "the letter 'a' throughout the several communications is always found to be out of line. The key bar is doubtless a trifle bent. Let us, therefore, see if, in any of the samples you have brought me, there exists a similar defect."