Scope and Contents From the Collection: The Edwin Thacher papers (MC 13) document the years 1873 through 1921, representing Thacher's career as a civil engineer in bridge construction, as well as the creation of Thacher's cylindrical slide rule. Legal materials include patent specifications for the bridge truss, and a patent on concrete arches with documentation emphasizing its history and review, 1881-1899. Additional legal materials include court documentation of Edwin Thacher vs. Mayor & City...