This notebook covers the period June-November 1889. It was used by Reginald Fessenden and Alex W. Brigham for notes on experimental projects and various other tasks in the chemical laboratory. There are also entries by Fessenden regarding structural alterations made to the chemical laboratory. The front cover is labeled "Alex Brigham #555." The spine is labeled "93." The pages are unnumbered. Approximately 50 pages have been used. Courtesy of Thomas Edison National Historical Park.