I found these!
I think they are really cool. They are two frames played in a loop very quickly. The two frames are from a stereograph, which takes two images from slightly different angles to simulate the depth we see as our eyes are in slightly different positions. Originally they would have been seen through a special viewer that allows you to see one picture in each eye, creating the illusion of depth. Here they have just been looped as animated .gif files. I particularly like the one of the ammunitions wagon exploding. It is very dramatic. I think the effect does create an illusion of depth in quite an unusual and eerie way. I would like to try and make a test animation using a similar technique.
If I were to take a series of images using two cameras in slightly different positions, I could play them back so that the frames were interspersed with each other: The 1st photo taken on camera A followed by the corresponding one on camera B- then the 2nd from camera A and so on. I could animate something moving within the series of stereoscopic images. It would be a bit crude and probably be impossible to make out what was happening, but I think it would be an interesting thing to try.