This is the second of two notebooks used by Clarke in 1890-1891 to record research into the "prior art" in connection with litigation involving the Sawyer-Man Electric Co. and their U.S. Patent 317,676. The entries consist primarily of summaries of published accounts relating to electric lighting. Some of these publications were entered as exhibits in the "McKeesport Case" (Consolidated Electric Light Co. v. McKeesport Light Co.) and the "Filament Case" (Edison Electric Light Co. v. United States Electric Lighting Co.). The label on the front cover is inscribed "No. 2. Sawyer-Man Pat. in suit 317,676, page 73" and "Fibrous-Carbon Arch Case." Clarke's name and address are also inscribed on the label. The book contains 108 numbered pages. Courtesy of the Henry Ford Museum and Greenfield Village Research Center.