Thomas Edison

Thomas Alva Edison (1847–1931) held over a thousand US patents and built the first industrial research laboratory at Menlo Park, an invention arguably more consequential than any single device that came out of it. He is quoted mostly for his views on persistence — the ratio of perspiration to inspiration, the thousands of ways that did not work. Some of those lines are documented in interviews and his own notebooks; others surfaced in print only decades after his death, recalled second-hand, and are better described as Edisonian in spirit than verified in wording. We distinguish between the two where the record allows.