Wikipedia contributors. (2024, February 11). Thomas Edison. In Wikipedia, The Free Encyclopedia. Retrieved February 22, 2024, from https://en.wikipedia.org/w/index.php?title=Thomas_Edison&oldid=1206025892
The texture of extrusive rocks is characterized by fine-grained crystals indistinguishable to the human eye, described as aphantic.
Over his desk Edison displayed a placard with Sir Joshua Reynolds’ famous quotation: “There is no expedient to which a man will not resort to avoid the real labor of thinking.” This slogan was reputedly posted at several other locations throughout the facility.