And that meant lots and lots of copper: copper for the wires he buried under the streets of New York, copper to go into homes and workplaces, copper to be strung around the wheels of generators. So much copper, in fact, that even though its price was falling, Edison still needed such vast quantities of the stuff that it threatened to put him out of business. He engineered his lightbulbs so they’d work with thinner copper wires and designed his electrical network in New York so it wouldn’t need the thick copper trunk wires he’d initially planned.
