Interior of a Bernal sphere with glider (1976) illustrated by Rick Guidice. Original public domain image from Wikimedia… https://www.rawpixel.com/image/10184837/image-face-plant-peopleFree Image from public domain licensePoliticians - Vanity Fair. 'The Smart Critic'. Mr. Bernal Osborne. 28 May 1870 https://www.rawpixel.com/image/12554033/politicians-vanity-fair-the-smart-critic-mr-bernal-osborne-may-1870Free Image from public domain licenseMemoria sobre el modo de hacer y administrar el subnitrate de mercurio, o pildora de Ugarte / escrita por José Antonio… https://www.rawpixel.com/image/13985290/image-paper-cartoon-bookFree Image from public domain license