Who was the literary character Sherlock Holmes modeled after?

Sherlock Holmes, Sir Arthur Conan Doyle's fictional detective with the knack for solving crimes through observation and reason, was modeled after Dr. Joseph Bell (born December 2, 1837 - died October 4, 1911) one of Conan Doyle's medical school professors. In fact, Doyle repeatedly said that Holmes was inspired by Joseph Bell, a surgeon at the Royal Infirmary of Edinburgh for whom he had worked as a clerk. Like Holmes, Bell was noted for drawing broad conclusions from minute observations. Bell was aware of this inspiration and took some pride in it. According to writer Irving Wallace, Bell was involved in several police investigations, mostly in Scotland, such as the Ardlamont Mystery of 1893.