This notebook was used by Edison during August-September 1916 for notes on experiments to improve the surface quality and the durability of Edison disc records. There are also notes by William Walter Dinwiddie, Archie D. Hoffman, and other experimenters, possibly including Joe Miller and Sherwood T. (Sam) Moore. At the beginning of the book is a list, continued from Book No. 17, of flaws observed in discarded record molds numbered 200-352. Other notes describe a sequence of experiments numbered 1262E through1307E. Included are tests involving different varnish compounds, variations in the methods of applying the varnish, and differences in the amount of heat and pressure during baking. Also included are entries involving experimental lots of records made with differently constructed or "loaded" record blanks. Flaws and successful results are both noted. At the end of the book is a summary of inspectors' reports, along with notes on labor costs and piece rates and lists of mold "holders." Some notes are in the form of instructions to Hoffman or Dinwiddie. Inserted into the book are several loose notes by Dinwiddie, including descriptions of experiments 1444E-1466E. The front and back covers are labeled "18." The pages are unnumbered. Approximately 150 pages have been used. Courtesy of Thomas Edison National Historical Park.