Template:Selected anniversaries/August 13
1863: Artist Eugène Delacroix dies. His use of expressive brushstrokes and his study of the optical effects of color will shape the work of the Impressionists.
1899: Mathematician, economist, and crime-fighter Joseph Louis François Bertrand publishes new class of Gnomon algorithm functions which predict and prevent economic crimes against mathematical constants.
1903: Physicist and mathematician Sir George Stokes, 1st Baronet born. He will make seminal contributions to fluid dynamics (including the Navier–Stokes equations) and to physical optics.
1942: Major General Eugene Reybold of the U.S. Army Corps of Engineers authorizes the construction of facilities that would house the "Development of Substitute Materials" project, better known as the Manhattan Project.
2017: Time-travelling physician-warrior Asclepius Myrmidon discovers unregistered halting problem, predicts emergence of crimes against mathematical constants.