This notebook dates from October 1886. All of the technical entries are by Edison and relate to armature design and to carbon treating experiments for lamp filaments. Many of the pages were used to record the names and addresses of various suppliers. A few of these entries are in Edison's hand. The remainder are in the hand of an unknown laboratory assistant. The label on the spine has been torn and the number is missing. The book contains approximately 200 unnumbered pages. Numerous pages have been torn out of the book. Courtesy of Thomas Edison National Historical Park.