[Untitled photo, possibly related to: Phelps Dodge refining company, El Paso, Texas. Sheets of pure copper, which had been… https://www.rawpixel.com/image/12295783/photo-image-person-public-domain-factoryFree Image from public domain licenseEl Paso, Texas, Phelps Dodge refining company. Electrolytic tanks in which sheets of pure copper are formed. The sheets are… https://www.rawpixel.com/image/12296694/photo-image-person-public-domain-factoryFree Image from public domain license