So our contemporary Sherlock has swapped his magnifying glass for a mobile. But as co-creators Steven Moffat and Mark Gatiss point out, this smartphone-savvy approach is not out of keeping with Arthur Conan Doyle’s original creation. Holmes has always been technologically adept. In fact, ‘A Study in Scarlet’ was the first work of fiction ever to represent the iconic magnifying glass as a tool for detection. Throughout the fifty-six stories, Holmes uses other optical devices – including a telescope in ‘The Hound of the Baskervilles’ and a microscope in ‘The Adventure of Shoscombe Old Place’ – to reveal clues otherwise hidden to the human eye. According to security specialist Robert Ing, this microscope would have been a cutting-edge Powell Lealand No. 1, demonstrating Holmes’s inclination towards new-fangled forensics. Another notable development was the typewriter, manufactured by Remington for commercial use from 1873. This machine is central to solving ‘A Case of Identity’, where Holmes identifies the criminal from the idiosyncrasies of his typed letter. In fact, Doyle is well ahead of his time here. FBI typewriter analysis only took off in 1933, when it led to the capture of a woman who had poisoned a batch of fudge.