Sir William Crookes. Watercolour painting by L. Ward [Spy], 1903. https://www.rawpixel.com/image/13964622/sir-william-crookes-watercolour-painting-ward-spy-1903Free Image from public domain licenseCartoon mammal adult pet. AI generated Image by rawpixel. https://www.rawpixel.com/image/12113492/image-white-background-catView licenseMoritz Heinrich Romberg. Lithograph by Wildt after J. Schlesinger. https://www.rawpixel.com/image/14014894/moritz-heinrich-romberg-lithograph-wildt-after-schlesingerFree Image from public domain license