Stereograph
Click on the image below to toggle back and forth between the left and right images from a 1901 stereograph.
Below, the original stereograph of a scene in the Bowery, New York, and a picture of it mounted on an antique stereoscope.
Below, an alternate way to convey the effect, by rapidly alternating the left and right images, though with disconcerting flicker.
See also A sense of relief on the Image Animations page for a similar treatment of the effects of parallax.