This book covers the period June 1890-June 1891. It contains a monthly breakdown of labor, material, and overhead costs among experimental projects and other laboratory accounts. The companies to which accounts were charged are sometimes indicated. The book contains 26 unnumbered sheets. The front cover is stamped "Abstract of Expenses. No.6. Laboratory, T. A. Edison. Orange, N.J."

This book was microfilmed in sections at a reduction ratio of 17:1.

Courtesy of Thomas Edison National Historical Park.