1793 – Two days after becoming the first recorded person to complete a transcontinental crossing of North America north of Mexico, Scottish-Canadian explorer Alexander Mackenzie reached the westernmost point of his journey and inscribed his name on a rock.
1802 – Gia Long conquered Hanoi and unified modern-day Vietnam, which had experienced centuries of feudal warfare.
1934 – Bank robber John Dillinger(pictured), whose exploits were sensationalized across the United States, was shot dead by police in an ambush outside the Biograph Theater in Chicago.
A 3D ray tracing of a glass molecular model, demonstrating the algorithm's ability in simulating depth of field (DOF), which is the distance between the nearest and farthest objects in a scene that appear acceptably sharp in an image. When much of the foreground and background of an image is sharp, its DOF is deep. The opposite is called shallow focus.
