Dearborn, MI: Edison Institute, 1936.
Softcover. Very Good. 430 pp, illustrated, in original green printed wrappers. Spine toned and lightly creased, contents clean. Signed with short inscription by Jehl ("to Kelly Campbell with best wishes" ) on front free endpaper. "In these pages is presented a picture of Menlo Park as it was during the great years of Thomas A. Edison's achievements. The purpose is twofold: To convey to our readers information about those events and to give visitors at the restored Menlo Park a better understanding of them" (Preface). Jehl was Edison's laboratory assistant.