link to webpage - didn't know how to upload animated GIF(?) file

I wish I knew how to upload an animated GIF (?) file, but I don't, so you will need to follow this link:

http://lala.cursivebuildings.com/tagged/reaching

Stereophotographs, or stereograms, or stereocards, are two photographs taken side-by-side, separated by approximately the distance between the human eyes, and used to simulate human binocular depth perception, on a flat surface, using a special viewer. Sir Charles Wheatstone is credited with inventing the first stereophotographic images in 1840. For a number of decades, they were quite popular with the public, and stereocards and stereoviewers were all the rage. They were later updated to the plastic 3-D viewers and circular cards with minaturized photographic slide-like inserts. What is so appealing about so many of the stereocards to me now, is the historical quality of the photographs. The gentleman at the above-listed website came up with a clever way to somewhat duplicate their qualities on a regular computer monitor, without the need of the original 3-D viewer. I believe he uses an an animated GIF file. Apparently he overlays one of the images on top of the other one, and uses animation features to switch back and forth between the two images, very quickly, so that the brain puts it together as a single image, which creates the illusion of depth, without the special viewer. Because the points of view are slightly different, however, the brain also perceives a slight 'wobble', and the slight differences between the two images also tends to make the lighting 'flicker'. I am extremely intrigued by these images. I am very interested in history, and physical reminders of the past, and I think that these images are absolutely fascinating. The flickering quality of the light gives one the impression that one is watching a video clip of very early moving picture images. I would like to learn how to do this technique. I have a few older stereocards in storage somewhere, and I haven't been able to find them yet. Meh!...