Edison passed away on October 18, 1931. The New York Times’ obituary for Edison can be read online, a beautifully written tribute to the inventor’s achievements.
Enlightment has over 400 hits in WorldCat (over 200 in the title field) and 42 in OhioLINK, making it a typo of high probability on the Ballard list. Your catalogue searchers will be enlightened as to the presence of these resources in the library collection only when these typos are fixed!
(Image of Edison’s light bulb from Encarta Encyclopedia Online)