As with most fiction, Arthur Conan Doyle took some creative liberties when building the world of Sherlock Holmes. Most notably, the 221B Baker Street that he describes does not quite match up with reality, and there are multiple theories about the actual location of Holmes and Watson’s flat.
The following analysis by Peter Liddell, adapted from a posting to the Hounds of the Internet in March 2001, registers a dissent from the suggestion that the "real" 221B Baker Street was the modern number 111.
The correct identification? Number 31 Baker Street, Liddell says.
The reasoning "is hardly original," he warns. "Most of my material is taken directly from Baring-Gould. B-G in turn quotes the analyses of several others (Bernard Davies and so on). I have added my own slant to this work based on my visit to the area last December."
I am aware of the "111" suggestion, first made by Dr. Gray Chandler Briggs in the 1930s, but this address was not in Baker Street as it was in Holmes' day, but further up in what was then York Place.
The facts (supposedly—all good researchers should personally check source material and I haven't been able to do this yet) are these. In the 1880's what we know now as Baker Street comprised three separately named streets. The most southerly part, from Portman Square up to Paddington Street was the original "Baker Street." From Paddington Street north to Marylebone Road it was "York Place" and north of Marylebone Road it was called "Upper Baker Street." South of the Portman Square entrance, the street name changed from Baker Street to Orchard Street, as it still does to this day.
York Place was incorporated into Baker Street in 1921 and "Upper Baker Street" became part of the unified Baker Street in 1930.
Originally, Baker Street addresses ran from number 1 (on the east side at Portman Square) up to 42 (on the east side at Paddington Street) and then from 44 (on the west side at Paddington Street down to number 85 (on the west side back at Portman Square). For some reason there never was a number 43.
After the merging of Baker Street and York Place, the houses were numbered more logically with "odd numbers" on the left (the west) and "evens" on the right (the east) looking north up the street. Thus the original "number 85" would have become "number 1" and the original "number 1" would have become "number 2." In this numbering there would have been a number 111, between York Street and Portman Mansions on what, in Holmes' day was York Place.
When Upper Baker Street was incorporated and the numbering was extended north of Marylebone Street, a "number 221" was at last created and that is where today's "blue plaque" is to be found. Watson and his editors would have been far-sighted indeed if they had had accurately anticipated this development back in 1887.
In "The Empty House," at the end of Watson's description of Holmes' circuitous journey from Cavendish Square to "Camden House," he writes:
"We emerged at last into a small road, lined with old, gloomy houses, which led us into Manchester Street, and so to Blandford Street. Here he turned swiftly down a narrow passage, passed through a wooden gate into a deserted yard, and then opened with a key the back door of a house. We entered together, and he closed it behind us."The place was pitch dark, but it was evident to me that it was an empty house. Our feet creaked and crackled over the bare planking, and my outstretched hand touched a wall from which the paper was hanging in ribbons. Holmes's cold, thin fingers closed round my wrist and led me forward down a long hall, until I dimly saw the murky fanlight over the door. Here Holmes turned suddenly to the right, and we found ourselves in a large, square, empty room, heavily shadowed in the corners, but faintly lit in the centre from the lights of the street beyond. There was no lamp near, and the window was thick with dust, so that we could only just discern each other's figures within. My companion put his hand upon my shoulder and his lips close to my ear.
"Do you know where we are?" he whispered.
"Surely that is Baker Street," I answered, staring through the dim window.
"Exactly. We are in Camden House, which stands opposite to our own old quarters."
We know that Watson often used real names but in a fictitious way. Therefore can we assume that simply because Watson says "Blandford Street" and that there really was a Blandford Street that this was actually the thoroughfare in question? However, if we do accept this, we need to look just where Blandford Street is. It does cross what was then Baker Street, emerging between numbers 16 and 17 on the east side. The key passage, if we accept "Blandford Street" at face value is "Here he turned swiftly down a narrow passage. . . ." The key question, of course, is which way was "down?" There are two passages leading off Blandford Street, to the east of Baker Street: Kendall Mews to the south and Blandford Mews to the north.
I have personally followed this part of route and am convinced that in every sense of the term, "down" does imply Kendall Mews rather than Blandford Mews. Turning from Blandford Street into Kendall Mews implies turning south, which many often consider to be "down." It implies turning towards the river and does tend to be "downhill." My recollection is of a definite slope downwards looking into the Mews. In the paragraphs above I have naturally used the term "up" to describe passage northward along Baker Street. I therefore support the "turning south" school of analysis which leads to the conclusion that Camden House was on the east side of Baker Street to the south of Blandford Street, i.e. in Holmes' day was a house numbered below 16. Because apparently access to the back of "Camden House" was directly off this passage and no other major street was crossed, "Camden House" could not have been as far south as George Street, i.e. would have had a number higher than 8.
The fanlight over the door and the right turn into the front ground floor room rule out a number of the possible houses. Having seen the buildings, I go along with the suggestion that "Camden House" was the second house down from Blandford Street, i.e. number 15 in Holmes' time and therefore I agree with the parallel conclusion that "221b" had similarly to be two or possibly three doors down from Blandford Street on the west side of Baker Street. As these west-side buldings have all gone now, I have to defer to those earlier, and luckier, analysts who were able to visit the houses and conclude that number 72 Baker Street (which would today have been number 31) was "The One True Place."
Anyone proposing todays 221, or 111, or any other address as the original site of their rooms has to reconcile this with Watson's description of their trek from Cavendish Square and the location of "Camden House," and with the unwavering references to "Baker Street" and not "York Place" or "Upper Baker Street."
No doubt the arguments will continue, but I for one struggle to accept any location to the north of Blandford Street, even though I know that this is a long way from "blue plaques" and "Sherlock Holmes Museums" and the like.