This ledger covers the period May 1903 to February 1911, with additional entries from 1917, 1925, and 1926. As the account book of final entry, it summarizes transactions pertaining to the business of the New Jersey Patent Co. Separate accounts detail cash, general expense, experimental, and patent transactions. Included are accounts with Edison, patent attorneys, and other individuals and companies. Edison's account covers the period June 1903- December 1910, with two additional entries from 1917. The entry for February 27, 1909, includes a $5,000,000 credit to Edison, indicated as "By Sundries." The front cover is labeled "Ledger N.J. Patent Co." The book contains 138 numbered pages and an index; many pages are blank.