He looked at me with reproachful eyes, as if I had suggested something immoral to him: "I'm very sorry, sir," he articulated with instructive courtesy. "But I am not only a charter member of the Argentine Locksmiths' Union, but also one of the principal framers of the Magna Carta of our organization. Nothing has been left to chance in it. If you should have the pleasure of reading this inspiring document, you would learn, in the chapter dedicated to 'Basic Maxims,' that the perfect locksmith is prohibited from collecting subsequent to the conclusion of the work.