three o'clock
`` You are right , '' replied the man of science , as if he were retracing instructions for a voyage to the North Pole . `` I will go through the Luxembourg , the Rue de Seine , the Pont des Arts , the Louvre , the Rue du Coq , the Rue Croix-des-Petits-Champs , the Rue des Fosses-Montmartre . It is the shortest route to the Faubourg Poissonniere . '' `` It is three o'clock , '' Madame Adolphe said . `` Your sister-in-law dines at six . You have three hours before you -- Yes -- you 'll be there , but you 'll be late . '' She searched her apron pocket for two sous , which she handed to the professor .