These reminiscences were selected from box 14 in Series 1 of the William J. Hammer Collection.They consist of approximately 70 pages of fragmentary notes. Most of the notes were assembled together in a three-ring binder, but there are also a few loose sheets. The reminiscences are not in strict chronological order, and many of the notes consist of disconnected paragraphs summarizing topics that are sometimes discussed more fully elsewhere. The first page bears the following inscription: "Mostly notes about Edison[.] Some notes of W. J. Hammer's work for Edison[.] Also re experiences abroad Maxim, Santos Dumont etc." The next several pages contain a list of lantern slides, brief reminiscences, and two pages of Edison aphorisms including his definition of genius as "1% Inspiration & 99% perspiration." These are followed by several sets of overlapping notes regarding his work at the Menlo Park laboratory and the Edison lamp factory, one of which bears the title "Reminiscences of Menlo Park N.J. Laboratory of Thomas A. Edison." Some of the anecdotes are of a humorous character, such as a recounting of "tricks [practical jokes] at Menlo Park" and a discussion of Edison's "pet names for his assistants."
Also included are several pages of notes regarding Hammer's residence in Germany during 1883 and 1884. On the backs of two of these pages are recollections of Samuel Insull, Edison's personal secretary and official in several of his companies, including an unflattering characterization of him as "Mr. Insull of the Edison Destruction Co." Two pages of notes discuss the various explanations for Edison's deafness. There are also reminiscences of the Paris International Electrical Exhibition of 1881, Hammer's residence in Great Britain in 1881 and 1882, and the Paris expositions of 1889 and 1901.