This letterbook covers the period January-April 1884. Many of the letters are by Edison. There is also correspondence by John R. Campbell and Samuel Insull. Most of Edison's letters are in the hand of Campbell or Insull, acting as Edison's secretary. Included is correspondence relating to the purchase of supplies and equipment and to the payment of overdue bills. Some of the letters pertain to the construction of a central station in Newburgh, New York. There is also a list of central station contracts and several cost and profit estimates for various stations. Among the recipients are William S. Andrews, S. Bergmann & Co., the Edison Lamp Co., the Edison Machine Works, Frank J. Sprague, and the Western Edison Light Co. The spine is labeled "1884" and is stamped "Letters No. 5. T. A. Edison. Central Station Construction Department." The book contains 492 numbered pages and an index. Approximately 40 percent of the book has been selected.