Safety inspector. This man uses a special lamp to test for gas throughout the mine. Old Ben number eight, West Frankfort… https://www.rawpixel.com/image/12241232/photo-image-person-wood-public-domainFree Image from public domain licenseView of the Petersburg Gas Works by Timothy H O Sullivan and Alexander Gardner https://www.rawpixel.com/image/14325912/view-the-petersburg-gas-works-timothy-sullivan-and-alexander-gardnerFree Image from public domain license