This notebook was probably begun on May 12, 1881, and used during the spring of 1881. It contains notes and drawings by Edward G. Acheson, afterwards a pioneer of the electrochemical industry, and Edward L. Nichols, later a professor of physics at Cornell University. There are also occasional notations by Edison, as well as entries by others. The entries describe the operations of several departments of the Edison Lamp Co., including apparatus and processes used in the production of lamps. Also included are formulae for determining the economy of lamps and for making calorimeter tests. Beginning on p. 61 is an entry by Nichols entitled "Method of lamp testing employed at the factory of the Edison Lamp Co." The front cover is labeled "From the Laboratory of T. A. Edison Menlo Park, N.J. No." The label is stamped "144" and is inscribed "Lamp Manufacturing" and "E. G. Acheson, May 12, 1881." The book contains 140 numbered pages. The second page is torn at the top. Numerous pages are blank or missing. Courtesy of Gary Hendershott.