Maurice Costello
Costello was born in Pittsburgh, Pennsylvania to Irish immigrants Ellen (née Fitzgerald; born 1853) and Thomas Costello (born 1852). He made his film debut in 1908, but was long believed to have debuted in "Adventures of Sherlock Holmes; or, Held for Ransom" (1905), supposedly playing the lead in what is regarded as the first serious film to feature the character of Sherlock Holmes, since it was preceded only by the 30-second comedy film "Sherlock Holmes Baffled" (1900). However, Holmesian scholar Leslie S. Klinger has written that the identification of Costello in the role is flawed. Klinger states that the first identification of Costello with the role was in Michael Pointer's "Public Life of Sherlock Holmes" published in 1975 but Pointer later realized his error and wrote to Klinger stating
Sherlock Holmes
The exact phrase, as well as close variants, can be seen in newspaper and journal articles as early as 1909; there is some indication that it was clichéd even then. The phrase "Elementary, my dear fellow, quite elementary" appears in P. G. Wodehouse's novel, "Psmith in the City" (1909–10), and "Elementary, my dear Watson, elementary" in his 1915 novel "Psmith, Journalist" (neither spoken by Holmes). The exact phrase "Elementary, my dear Watson" is used by protagonist Tom Beresford in Agatha Christie's 1922 novel "The Secret Adversary". It also appears at the end of the 1929 film "The Return of Sherlock Holmes", the first Holmes sound film. The phrase became familiar with the American public in part due to its use in The Rathbone-Bruce series of films from 1939 to 1946.