“Not in so many words,” Vance pointed out. “But after I had shown you the approximate height of the murderer, and it didn’t correspond at all to that of the young lady you suspected, I knew your active mind was busy looking around for another possibility. And, as the lady’s inamorato was the only other possibility on your horizon, I concluded that you were permitting your thoughts to play about the Captain. Had he, therefore, been the stipulated height, you would have said nothing; but when you argued that the murderer might have stooped to fire the shot, I decided that the Captain was inord’nately tall. . . . Thus, in the pregnant silence that emanated from you, old dear, your spirit held sweet communion with mine, and told me that the gentleman was a six-footer no less.”
“I see that you include mind-reading among your gifts,” said Markham. “I now await an exhibition of slate-writing.”
His tone was irritable, but his irritation was that of a man reluctant to admit the alteration of his beliefs. He felt himself yielding to Vance’s guiding rein, but he still held stubbornly to the course of his own previous convictions.
“Surely you don’t question my demonstration of the guilty person’s height?” asked Vance mellifluously.
“Not altogether,” Markham replied. “It seems colorable enough. . . . But why, I wonder, didn’t Hagedorn work the thing out, if it was so simple?”
“Anaxagoras said that those who have occasion for a lamp, supply it with oil. A profound remark, Markham—one of those seemingly simple quips that contain a great truth. A lamp without oil, y’ know, is useless. The police always have plenty of lamps—every variety, in fact—but no oil, as it were. That’s why they never find anyone unless it’s broad daylight.”
Markham’s mind was now busy in another direction, and he rose and began to pace the floor.
“Until now I hadn’t thought of Captain Leacock as the actual agent of the crime.”
“Why hadn’t you thought of him? Was it because one of your sleuths told you he was at home like a good boy that night?”
“I suppose so.” Markham continued pacing thoughtfully. Then suddenly he swung about. “That wasn’t it, either. It was the amount of damning circumstantial evidence against the St. Clair woman. . . . And, Vance, despite your demonstration here to-day, you haven’t explained away any of the evidence against her.—Where was she between twelve and one? Why did she go with Benson to dinner? How did her hand-bag get here? And what about those burned cigarettes of hers in the grate?—they’re the obstacle, those cigarette butts; and I can’t admit that your demonstration wholly convinces me—despite the fact that it is convincing—as long as I’ve got the evidence of those cigarettes to contend with, for that evidence is also convincing.”