In July 1891, four intrepid women from Lowell, Massachusetts, set off for an adventure they would remember all their lives. Calling themselves “the Merrie Trippers,” they created a journal of their two-week trip to Great Brewster Island complete with entries, illustrations, and photographs, everything but their real names. Volunteers from the Friends of the Boston Harbor Islands, led by author Stephanie Schorow, dove into the journal’s mysteries and published “A Boston Harbor Islands Adventure: The Great Brewster Journal of 1891” in 2023. In an illustrated lecture on Oct. 26 at 2 p.m., the authors will explain how they uncovered the women’s identities (and more) and were able to create a portrait of 19th century women’s lives.