On this day in 1915, The Valley of Fear by Arthur Conan Doyle is published in novel form.
Sherlock Holmes had been a popular character since he first appeared in the story "A Study in Scarlet," published in Beeton's Christmas Annual in 1887. The thin, highly strung detective with extraordinary deductive powers was modeled partly on Dr. Joseph Bell, a medical school teacher at the University of Edinburgh, where Holmes' creator studied.