"It is obvious. And now, you see, I had narrowed the field down considerably. The possession of a gray garment was a third point which, granting the son's statement to be correct, was a certainty. We have come now out of mere vagueness to the definite conception of an Australian from Ballarat with a gray cloak."

"Certainly."

"And one who was at home in the district, for the pool can only be approached by the farm or by the estate, where strangers could hardly wander."

"Quite so."

"Then comes our expedition of to-day. By an examination of the ground I gained the trifling details which I gave to that imbecile Lestrade, as to the personality of the criminal."

"But how did you gain them?"

"You know my method. It is founded upon the observation of trifles."

"His height I know that you might roughly judge from the length of his stride. His boots, too, might be told from their traces."

"Yes, they were peculiar boots."

"But his lameness?"

"The impression of his right foot was always less distinct than his left. He put less weight upon it. Why? Because he limped--he was lame."

"But his left-handedness."

"You were yourself struck by the nature of the injury as recorded by the surgeon at the inquest. The blow was struck from immediately behind, and yet was upon the left side. Now, how can that be unless it were by a left-handed man? He had stood behind that tree during the interview between the father and son. He had even smoked there. I found the ash of a cigar, which my special knowledge of tobacco ashes enables me to pronounce as an Indian cigar. I have, as you know, devoted some attention to this,............