“Wait: I was just going to explain. They take some of the best gelatine, and allow it to soak in cold water. When it becomes thoroughly softened, they heat it until it forms a liquid, of moderate consistency. Then when it is just cool enough, they pour a nice little covering of it upon the footprint.” Lecoq felt the irritation that is natural to a person who has just heard a bad joke, or who has lost his time in listening to a fool. “Enough!” he interrupted, angrily. “That method can be found in all the manuals. It is excellent, no doubt, but how can it serve us? Have you any gelatine about you?” “No.” “Nor have I. You might as well have counseled me to pour melted lead upon the footprints to fix them.” They continued their way, and five minutes later, without having exchanged another word, they reentered the Widow Chupin’s hovel. The first impulse of the older man would have been to rest to breathe, but Lecoq did not give him time to do so. “Make haste: get me a dish--a plate--anything!” cried the young detective, “and bring me some water; gather together all the boards and old boxes you can find lying about.” While his companion was obeying him, Lecoq armed himself with a fragment of one of the broken bottles, and began scraping away furiously at the plastered wall that separated the two rooms. His mind, disconcerted at first by the imminence of this unexpected catastrophe, a fall of rain, had now regained its equilibrium. He had reflected, he had thought of a way by which failure might possibly be averted--and he hoped for ultimate success. When he had accumulated some seven or eight handfuls of fine plaster dust, he mixed one-half with a little water so as to form a thin paste, leaving the rest untouched on the side of the plate. “Now, papa,” said he, “come and hold the light for me.” When in the garden, the young man sought for the deepest and most distinct of the footprints, knelt beside it, and began his experiment, trembling with anxiety. He first sprinkled upon the impression a fine coating of dry plaster, and then upon this coating, with infinite care, he poured his liquid solution drop by drop. What luck! the experiment was successful! The plaster united in a homogeneous mass, forming a perfect model of the impression. Thus, after an hour’s labor, Lecoq possessed half a dozen of these casts, which might, perhaps, be a little wanting in clearness of outline, but which were quite perfect enough to be used as evidence. The young detective’s alarm had been well founded, for it was already beginning to rain. Still, he had plenty of time to cover a number of the footprints with the boxes and pieces of board which Father Absinthe had collected, thus placing them, as it were, beyond the reach of a thaw. Now he could breathe. The authorities might come, for the most important part of his task was completed. V