[Untitled photo, possibly related to: Inoculation of guinea pig. Experimental farm of Department of Agriculture, Prince… https://www.rawpixel.com/image/12240137/photo-image-face-hand-personFree Image from public domain licenseNashville, Tennessee. Vultee Aircraft Company. Installing landing gear on wing parts in a sub-assembly section. Sourced from… https://www.rawpixel.com/image/12304030/image-face-person-airplaneFree Image from public domain license