a French political, economic and socialist theorist and businessman whose thought had a substantial influence on politics, economics, sociology and the philosophy of science.

an Italian poet, writer, literary critic and teacher. He was very noticeably influential, and was regarded as the official national poet of modern Italy.

a French physicist, established as an authority in the field of optics and spectroscopy

a French post-Impressionist artist. He devised the painting techniques known as chromoluminarism and pointillism and used conté crayon for drawings on paper with a rough surface.

an Austrian mathematician and physicist. He is celebrated for his principle that the observed frequency of a wave depends on the relative speed of the source and the observer

an English scientist, inventor, and photography pioneer who invented the salted paper and calotype processes, precursors to photographic processes of the later 19th and 20th centuries.