This book covers the years 1875-1876 and 1878-1879 and was used both as a daybook for the firm of Edison & Murray and as a time book for the Edison laboratory at Menlo Park. The daybook entries are on pages 8-169 and cover the period January 1875-January 1876. The time book (pages 190-202) lists work done between October 1878 and January 1879. There are also undated entries on pages 384 and 396. The cover is labeled "T.A. EDISON BILL BOOK INVOICE BOOK Jany 1875 to Dec 1878." The book contains 396 numbered pages.