A labelled section through a porter brewery. Engraving by Mutlow, c. 1812, after J. Farey. https://www.rawpixel.com/image/13957653/image-cartoon-public-domain-factoryFree Image from public domain licenseThree inventions: a torsion-bar for measuring forces, a drill-bit, and a lens. Engraving by Mutlow, c. 1812, after J. Farey. https://www.rawpixel.com/image/13976379/image-paper-cross-public-domainFree Image from public domain license