This letterbook covers the periods April-November 1881, June-July 1884, July 1885, and July-September 1888. Most of the correspondence is by Edison and is in the hand of Samuel Insull or Alfred O. Tate, acting as Edison's secretaries. Most of the letters from the years 1881-1885 concern routine stock transactions of the Electric Tube Co. and the Edison Electric Light Co. There are also miscellaneous other routine letters relating to the business of these companies. A few of the letters from 1888 deal with more substantive matters. There are several letters pertaining to the phonograph business and one letter concerning the use of electricity to eliminate unwanted animals. The front cover is marked "1881." The book contains 466 numbered pages and an index; pages 28-466 are blank. Only five pages of letters from 1888 have been selected.