This notebook contains only a few dated entries, covering the period April 1873-November 1874 It is entirely by Edison and relates to telegraphy. Pages 1-55 contain notes and drawings of Edison's and other inventors' telegraph devices. They may have been intended for use as illustrations to accompany Edison's essays on telegraphy and electricity (see NS-74-002, Unbound Notes and Drawings). There is one dated entry (page 53) for April 17, 1873. Pages 57-63 contain notes and drawings on duplex telegraphy dated September 10-12 and November 2, 1874. Pages 64-66 contain Edison's drawings and notes on what Ezra T. Gilliland remembered, probably in 1875, about H. Nicholson's work on multiple telegraphy during the early 1870s. The book contains 320 numbered pages.
Blank pages: 67-320. Courtesy of Thomas Edison National Historical Park.