Final answer:
Sherlock Holmes deduces Helen Stoner's method of travel through observation of her weary appearance, her damp and muddy attire, and wheel marks outside his door, all indicative of a morning train followed by a cab ride.
Step-by-step explanation:
In "The Adventure of the Speckled Band," Sherlock Holmes astutely deduces the method of Helen Stoner's travel based on his keen observation skills and deductive reasoning. Holmes observes that Helen appears weary, that her attire is damp and muddy, and that there are fresh marks of wheels on the road outside his home, which indicate that a vehicle has recently passed by. This, combined with his knowledge of the train schedules and the distance of Helen's estate from his office, allows him to deduce that she took a train early in the morning and then hired a cab from the station to his doorstep.
Holmes might also notice certain signs on Helen herself, such as clay on her clothes that matches the clay from the road near the train station, or the timing of her arrival, which would be too early for other forms of transport, like a horse and carriage from her home. All these observable clues contribute to his conclusion. The detailed observation and deductive reasoning by Sherlock Holmes are classic hallmarks of his character and are vividly demonstrated in this Sherlock Holmes short story by Sir Arthur Conan Doyle.