Read it through once

Sherlock Holmes sniffed sardonically. “Lecoq was a miserable bungler,” he said, in an angry voice; “he had only one thing to recommend him, and that was his energy. That book made me positively ill. The question was how to identify an unknown prisoner. I could have done it in twenty-four hours. Lecoq took six months or so. It might be made a text-book for detectives to teach them what to avoid.”