God, I love the Victorians and their nifty do-dads.
CNN posted these awesome, Halloween-inspired stereo card images that were created by the London Stereoscopic Company in 1864. For those unfamiliar with the technology, a stereo card featured two almost identical images on the same card, with a few differences. You use a stereoscope, a special pair of glasses, to view the cards (see left).
The Holmes Stereoscope was the most popular form of these types of glasses and I still see these now and again at antique malls. (Side note: old does not necessarily mean valuable.)
When you viewed the card through the stereoscope, the differences in the images created a 3D-like effect.
Yeah, because the Victorians invented 3D.
I maintain that Victorian Era technology is awesome.