This notebook is by Charles Batchelor and covers the period July-August 1878. It contains notes and acoustic recordings from an investigation of noise on the Metropolitan Elevated Railroad, along with notes and drawings of the aurophone and megaphone. The notebook is similar in style to the thirteen soft-cover tablet notebooks that comprise Unbound Notebook, Vol.8. The cover is labeled "Laboratory Notes Number 62 T.A. Edison, Menlo Park, N.J." It also contains an inscription, written by Batchelor: "Experiments to determine the cause of the noise on the Metropolitan Elevated Railroad." About 30 pages of this unnumbered book have been used. Courtesy of Thomas Edison National Historical Park.