Sherlock Holmes is, without a doubt, the most famous detective of all time. To this day, people continue to seek his assistance, writing him at 221B Baker Street, where his deerstalker cap, meerschaum pipe, violin, and cocaine syringe still reside, along with mementos from his numerous cases. Dr. John Watson began detailing the adventures of the world’s foremost “consulting detective” in 1887 and, except for the 10-year period when Holmes was missing and presumed dead, continued to do so for the next 40 years. During those years, Sherlock Holmes undertook more than 60 cases, solving even those that had baffled Scotland Yard. The detective’s famous deductions were based on the most arcane data; Holmes was equipped with an incredibly comprehensive knowledge of his surroundings. Learn more about them yourself when social historian Virginia W. Newmyer gives a slide-illustrated lecture on Victorian England titled “The World of Sherlock Holmes,” at 6 p.m. at the National Museum of American History’s Carmichael Auditorium, 14th & Constitution Ave. NW. $13. (202) 357-3030. (Mark W. Sullivan)