British writer, and creator of Sherlock Holmes, the best-known detective in literature and the embodiment of ratiocination, or deductive reasoning. ALS, one page, 4 x 7, Undershaw, Hindhead letterhead, no date. Short letter to a gentleman. In full, 'Many thanks for your kind note. Please excuse the intrusion of a stranger.' Double matted and framed with the original mailing envelope, addressed in Doyle's hand, and a nice image of the author, to an overall size of 15.5 x 17. In fine condition. COA John Reznikoff/University Archives and RRAuction COA.