What you do in this world is a matter of no consequence. The question is, what can you make people believe that you have done?(As recorded by Dr John H Watson and reportedby Sir Arthur Conan Doyle in A Study in Scarlet)
However true that may be, many other things have changed in the 121 years since Holmes and Watson set out to unravel the "scarlet thread of murder running through the colourless skein of life".
For example, Holmes' official portraitist, Sidney Paget (late of The Strand Magazine) may have shown his subject smoking one of his many pipes (above) or, here, occupying a SMOKING compartment when travelling with Watson by train...
But, today, pipes are definitely not permitted on the London Underground --- even, as you can see, at Baker Street station!