William Thomson, Baron Kelvin. Photograph by T. & R. Annan & Sons. https://www.rawpixel.com/image/14017964/william-thomson-baron-kelvin-photograph-annan-sonsFree Image from public domain licenseA bearded man walking the streets with his hat under his arm deeply engrossed in reading a book. Etching by J.T. Smith, 1815. https://www.rawpixel.com/image/13975442/image-paper-cartoon-faceFree Image from public domain licenseFree sheep behind a barb wire fence image, public domain animal CC0 photo. https://www.rawpixel.com/image/5906880/photo-image-background-public-domain-natureFree Image from public domain licenseHippocrates. Stipple engraving by M. Bovi, 1796, after A. Day. https://www.rawpixel.com/image/13978465/hippocrates-stipple-engraving-bovi-1796-after-dayFree Image from public domain licenseEdward Jenner. Mezzotint by J. R. Smith, 1800, after himself. https://www.rawpixel.com/image/13994478/edward-jenner-mezzotint-smith-1800-after-himselfFree Image from public domain licenseAlbrecht Dürer with a reversed copy of Dürer's print of a knight, death and the devil beneath. Engraving by J. Corner, 1825… https://www.rawpixel.com/image/13988860/image-horse-face-personFree Image from public domain licensePortret van Pieter Bodding van Laer (1752 - 1789) by Caspar Jacobsz Philips https://www.rawpixel.com/image/13783485/portret-van-pieter-bodding-van-laer-1752-1789-caspar-jacobsz-philipsFree Image from public domain licenseRichard Warren. Stipple engraving by G. Bartolozzi, 1810, after W. Evans after G. Stuart. https://www.rawpixel.com/image/14001490/image-face-person-artFree Image from public domain licenseUnidentified young man, printed in vignette-style by Levi Mumper https://www.rawpixel.com/image/14306244/unidentified-young-man-printed-vignette-style-levi-mumperFree Image from public domain licenseHenry Baker. Stipple engraving by W. Nutter, 1812, after J. Thomson. https://www.rawpixel.com/image/14010839/henry-baker-stipple-engraving-nutter-1812-after-thomsonFree Image from public domain licenseRichard Watson. Stipple engraving by Holl after G. Romney. https://www.rawpixel.com/image/13993012/richard-watson-stipple-engraving-holl-after-romneyFree Image from public domain licenseGuillaume, Baron Dupuytren. Stipple engraving by A. Tardieu. https://www.rawpixel.com/image/13976395/guillaume-baron-dupuytren-stipple-engraving-tardieuFree Image from public domain licenseRichard Warren. Stipple engraving by G. Bartolozzi, 1810, after W. Evans after G. Stuart. https://www.rawpixel.com/image/13980943/image-face-person-artFree Image from public domain licenseSir William Withey Gull. Watercolour by C. Pellegrini [Ape], 1875. https://www.rawpixel.com/image/13961760/sir-william-withey-gull-watercolour-pellegrini-ape-1875Free Image from public domain licenseJapans motief met en man en een bij (1856 - 1897) by Henri Charles Guérard https://www.rawpixel.com/image/13738696/japans-motief-met-man-een-bij-1856-1897-henri-charles-guerardFree Image from public domain licenseSaint Francis of Assisi holding a Bible and a crucifix. Engraving. https://www.rawpixel.com/image/13978150/saint-francis-assisi-holding-bible-and-crucifix-engravingFree Image from public domain licenseBaksa, Formosa [Taiwan]. Photograph, 1981, from a negative by John Thomson, 1871. https://www.rawpixel.com/image/13991971/photo-image-face-person-musicFree Image from public domain licenseSergeant der O.I. Artillerie (1835 - 1850) by Albertus Verhoesen and Johannes Paulus Houtman https://www.rawpixel.com/image/13748550/image-paper-face-personFree Image from public domain licensePeter Wells, surgeon to the Bristol Royal Infirmary. Oil painting by an English painter, before ca. 1786. https://www.rawpixel.com/image/14005808/image-face-person-artFree Image from public domain licenseJoseph Townsend. Stipple engraving by W. Holl, 1805, after J. Opie, 1780. https://www.rawpixel.com/image/13999173/joseph-townsend-stipple-engraving-holl-1805-after-opie-1780Free Image from public domain licenseAn apothecary with instruments of his profession seated in an arched window. Lithograph by M. Vernaut after G. Metsu. https://www.rawpixel.com/image/14004514/image-cartoon-face-personFree Image from public domain licenseAn orphan brother and sister embracing each other. Lithograph by Louisa Corbaux after F.M. Miller. https://www.rawpixel.com/image/14002634/image-cartoon-face-personFree Image from public domain licenseA woman is upset as a man takes his leave of her. Engraving after M. van Cleve. https://www.rawpixel.com/image/14012852/woman-upset-man-takes-his-leave-her-engraving-after-van-cleveFree Image from public domain licenseA number of twisted metal tubes rising up towards the sky next to a tall building. Original public domain image from… https://www.rawpixel.com/image/3303867/free-photo-image-perspective-line-art-architectureFree Image from public domain licenseA woman at her devotions. Mezzotint by J. Smith after Sir G. Kneller. https://www.rawpixel.com/image/14006880/woman-her-devotions-mezzotint-smith-after-sir-knellerFree Image from public domain licenseJohn Taylor, mining engineer and geologist. Lithograph after T. Lawrence. https://www.rawpixel.com/image/13978238/john-taylor-mining-engineer-and-geologist-lithograph-after-lawrenceFree Image from public domain licenseHand holding a camera. Original public domain image from Wikimedia Commons https://www.rawpixel.com/image/3286103/free-photo-image-hand-abstract-phone-lightFree Image from public domain licenseUnidentified man with long, bushy muttonchops wearing a hat, standing, with one arm on a chair back by Edward D Ritton https://www.rawpixel.com/image/14308855/image-face-person-baseballFree Image from public domain licenseA girl closely followed by a young man rushes towards an old lady sitting on a stool outside a cottage. Stipple engraving. https://www.rawpixel.com/image/13967851/image-cat-person-artFree Image from public domain licenseFree bun sprinkled with icing sugar image, public domain dessert CC0 photo. https://www.rawpixel.com/image/5904709/photo-image-background-public-domain-foodFree Image from public domain licenseSaint Nicholas of Myra and Bari. Chalk manner engraving by Clemente Nicoli, 1786, after G.F. Barbieri, il Guercino. https://www.rawpixel.com/image/13980431/image-cartoon-face-personFree Image from public domain licenseGiovanni Aldini. Stipple engraving by L. Schiavonetti after P. Violet, 1803. https://www.rawpixel.com/image/13975948/giovanni-aldini-stipple-engraving-schiavonetti-after-violet-1803Free Image from public domain licenseJohn Armstrong. Mezzotint by S. W. Reynolds after Sir J. Reynolds. https://www.rawpixel.com/image/13992469/john-armstrong-mezzotint-reynolds-after-sir-reynoldsFree Image from public domain licenseAuguste Nélaton. Wood engraving by W.B. after Ch. Reutlinger. https://www.rawpixel.com/image/13981405/auguste-nelaton-wood-engraving-wb-after-ch-reutlingerFree Image from public domain licenseSpiro, A Greek from the Ionian Islands by Dr William Robertson https://www.rawpixel.com/image/14312476/spiro-greek-from-the-ionian-islands-william-robertsonFree Image from public domain licenseFrançois Vincent Raspail. Wood engraving by E. Montigneul. https://www.rawpixel.com/image/14017443/francois-vincent-raspail-wood-engraving-montigneulFree Image from public domain licenseUnidentified Civil War solding wearing a cap, in quasi-Napoleanic stance by Charles DeForest Fredricks https://www.rawpixel.com/image/14307033/image-face-person-baseballFree Image from public domain licenseJean-Baptiste Bouillaud. Lithograph by C. Bornemann after P.L. Pierson. https://www.rawpixel.com/image/13993785/jean-baptiste-bouillaud-lithograph-bornemann-after-pl-piersonFree Image from public domain licensePearl Crescent Butterfly on Butterfly Weed flower. Free public domain CC0 photo. https://www.rawpixel.com/image/6202234/photo-image-flower-public-domain-natureFree Image from public domain licenseSaint Dominic Guzman. Engraving after C. Cort, 1573, after B. Spranger. https://www.rawpixel.com/image/13989319/saint-dominic-guzman-engraving-after-cort-1573-after-sprangerFree Image from public domain licenseSir William John Ritchie Simpson. Photograph by Douglas Scott. https://www.rawpixel.com/image/13999255/sir-william-john-ritchie-simpson-photograph-douglas-scottFree Image from public domain license