This letterbook covers the period June-September 1884 and contains correspondence relating both to the Edison Construction Department and to the Edison Machine Works. Some of the letters are by Edison. There is also correspondence by Samuel Insull and Charles Batchelor Most of Edison's letters are in the hand of Insull, acting as Edison's secretary. Included is correspondence pertaining to the shipment of dynamos and the payment of overdue bills. There are also letters about the payment of rent for the Goerck Street plant of the Edison Machine Works in New York City. The front cover is marked "Construction Dept No 7" and is stamped "T. A. Edison. Construction Dept., 65 Fifth Ave., New York." The spine is labeled "1884" and is stamped "Letters C.D. 7." The book contains 497 numbered pages and an index. Pages 78-497 are blank. Less than 10 percent of the documents have been selected. Courtesy of Thomas Edison National Historical Park.