The character was based on William James Maurice Bottle (1875-1956), who performed in music halls and theatres from 1901 onwards as "Datas: The Memory Man". Bottle combined his prodigious ability to recall facts with his quick wit, a necessity for dealing with hecklers in the audience. The performance in the film seems to capture some of this — "How old is Mae West? / I know, sir, but I never tell a lady's age." — and Watson's appearance bears more than a passing resemblance to Datas. Watson also uses Datas' well-known catchphrase, "Am I right, sir?"
Speaking to François Truffaut about the The 39 Steps, Hitchcock recalled:
There was also another interesting character in the film, Mr. Memory. He's based on a true-life music-hall personality called Datas. The audience would ask him questions about major events, like: "When did the Titanic sink?" and he would give the correct answer [...] The whole idea is that the man is doomed by his sense of duty. Mr. Memory knows what the thirty-nine steps are, and when he is asked the question, he is compelled to give the answer.
Hitchcock expressed similar sentiments to Charlotte Chandler:
Mr. Memory is one of my favorite characters. I have many favorites among those who people my films, but none of whom I’m fonder than Mr. Memory. The character is based on a real person named Datas, who had an act in London when I was young. I found Memory’s compulsion to answer quite fascinating. He was neither a magician nor a genius, you see. Memory had this one special talent. Otherwise, he would have been ordinary, but his pride in it made him a victim. He couldn't help showing it off, even at the cost of his life.
In the film, one of the questions asked to Mr. Memory — which he doesn't answer — is "When was Crippen hanged?" In 1932, Bottle published his memoirs in which he recounted the many times he met with Hawley Harvey Crippen and his wife, Cora, who was a music hall singer under the stage name "Belle Elmore". Bottle later met Crippen's executioner, John Ellis, who recounted to him the details of Crippen's hanging.
Notes & References
- See this photograph of Datas on John Bottle's web site.
- Hitchcock (1967) by François Truffaut, page 98
- It's Only a Movie: Alfred Hitchcock - A Personal Biography (2005) by Charlotte Chandler
- "Datas: The Memory Man", published in 1932 by Wright & Brown. See John Bottle's web site for a transcript of the relevant chapter.