This notebook covers the period December 1887-April 1888. It was used by Edison and Erwin Von Wilmowsky for notes regarding chemical orders and the preparation of compounds, primarily for use in lamp filament and insulation experiments. The front cover is labeled "Order Book E.W. Dept." The spine is labeled "41." The book contains 25 numbered pages. Eight loose pages have been inserted into the book. Courtesy of Thomas Edison National Historical Park.