“Ah, I comprehend! I had forgotten the imprints which I must have left when I went down to the rock. It was dark, you understand?—and naturally I did not perceive that I was leaving traces. So that was it, Sir Clinton?” Armadale was obviously puzzled. He turned to Mme. Laurent-Desrousseaux. “What size of shoe do you wear, madame?” She glanced at her neatly shod feet. “These shoes I have bought in London a few days ago. The _pointure_—the size, you call it, isn't it?—was No. 4.” Armadale shrugged his shoulders, as though to express his disbelief. “Measure these prints on the sand here, inspector,” Sir Clinton suggested. Armadale drew out his tape-measure and took the dimensions of the footmarks left by Mme. Laurent-Desrousseaux. “And the length of step also, inspector,” Sir Clinton suggested. “They correspond with the tracks down to the rock, true enough,” the inspector admitted, when he completed his task. “But only a 3½ shoe could have made them.” Sir Clinton laughed, though not sneeringly. “Would you lend me one of your shoes for a moment, madame?” he asked. “You can lean on me while it's off, so as not to put your foot on the wet sand.” Mme. Laurent-Desrousseaux slipped off her right shoe and held it out. “Now, inspector, there's absolutely no deception. Look at the number stamped on it. A four, isn't it?” Armadale examined the shoe, and nodded affirmatively. “Now take the shoe and press it gently on the sand alongside a right-foot print of Mme. Laurent-Desrousseaux—that one there will do. See that you get it square on the sand and make a good impression.” The inspector knelt down and did as he was told. As he lifted the shoe again, Wendover saw a look of astonishment on his face. “Why, they don't correspond!” he exclaimed. “The one I've made just now is bigger than the other.” “Of course,” the chief constable agreed. “Now do you see that a No. 4 shoe can make an impression smaller than itself if you happen to be walking in sand or mud? While you were hunting for people with 3½ shoes, I was turning my attention to No. 4's. There aren't so many in the hotel, as you know. And it so happened that I began with Mme. Laurent-Desrousseaux. She was good enough to go for a walk with me; and by counting her steps I gauged the length of her pace. It corresponded to the distance on the tracks.” Mme. Laurent-Desrousseaux was examining Sir Clinton with obvious admiration, not wholly unmixed with a certain uneasiness. “You seem to be very adroit, Sir Clinton,” she observed. “But what is this about the length of my pace?” “The inspector is accustomed to our English girls, madame, who have a free-swinging walk and therefore a fairly long step. From the length of the steps on the sand he inferred that they had been made by someone who was not very tall—rather under the average height. He forgot that some of you Parisians have a different gait—more restrained, more finished, shall we say?”