"They are coming from work in the yard."
"Dirty-looking rascals, but I suppose every one has some little immortal spark concealed about him. You would not think it, to look at them. There is no a priori probability about it. A strange enigma is man!"
"Some one calls him a soul concealed in an animal," I suggested.
"Winwood Reade is good upon the subject," said Holmes. "He remarks that, while the individual man is an insoluble puzzle, in the aggregate he becomes a mathematical certainty. You can, for example, never foretell what any one man will do, but you can say with precision what an average number will be up to. Individuals vary, but percentages remain constant. So says the statistician. But do I see a handkerchief? Surely there is a white flutter over yonder."
"Yes; it is your boy," I cried. "I can see him plainly."
"And there is the 'Aurora,'" exclaimed Holmes, "and going like the devil! Full speed ahead, engineer. Make after that launch with the yellow light. By heaven, I shall never forgive myself if she proves to have the heels of us!"
She had slipped unseen through the yard entrance, and passed behind two or three small craft, so that she had fairly got her speed up before we saw her. Now she was flying down the stream, near in to the shore, going at a tremendous rate. Jones looked gravely at her and shook his head.
"She is very fast," he said. "I doubt if we shall catch her."
"We must catch her!" cried Holmes, between his teeth. "Heap it on, stokers! Make her do all she can! If we burn the boat we must have them!"
We were fairly after her now. The furnaces roared, and the powerful engines whizzed and clanked like a great metallic heart. Her sharp, steep prow cut through the still river water, and sent two rolling waves to right and to left of us. With every throb of the engines she sprung and quivered like a living thing. One great yellow lantern in our bows threw a long, flickering funnel of light in front of us. Right ahead a dark blur upon the water showed where the "Aurora" lay, and the swirl of white foam behind her spoke of the pace at which she was going. We flashed past barges, steamers, merchant vessels, in and out, behind this one and round the other. Voices hailed us out of the darkness, but still the "Aurora" thundered on, and still we followed close upon her track.