This notebook was used by William Walter Dinwiddie, Archie D. Hoffman and possibly other experimenters during June-July 1917 for notes on efforts to improve Edison disc records. There are numerous comments by Edison on the work performed. The entries pertain primarily to a sequence of experiments numbered from 1568E through 1656E. Included are tests of experimental lots of record blanks constructed by different methods or prepared with different ingredients. Some tests involve records printed with nickel faced molds. The entries generally consist of instructions by Dinwiddie or Hoffman describing the experimental records wanted, accompanied by evaluations of the test records based on durability, thickness, and edging . In one entry Edison criticizes Dinwiddie and others for their experiment planning, while in another he complains that his "instructions were not followed in this experiment." The front cover is labeled "Disc Record" and "22"; the back cover is labeled "22." The pages are unnumbered. Approximately 190 pages have been used. Courtesy of Thomas Edison National Historical Park.