“The earliest type of stereoscope was invented by Sir Charles Wheatstone in 1838. It used a pair of mirrors at 45 degree angles to the user’s eyes, each reflecting a picture located off to the side. It demonstrated the importance of binocular depth perception by showing that when two pictures simulating left-eye and right-eye views of the same object are presented so that each eye sees only the image designed for it, but apparently in the same location, the brain will fuse the two and accept them as a view of one solid three-dimensional object.”
An impressive feat of imagination and invention, no matter which way you look at it.
“In 1861 Oliver Wendell Holmes created and deliberately did not patent a hand-held, streamlined, much more economical viewer than had been available before. The stereoscope, which dates from the 1850s, consisted of two prismatic lenses and a wooden stand to hold the stereo card. This type of stereoscope remained in production for a century and there are still companies making them in limited production currently.”
After seeing the photo(s) above and other stereoptic cards in a book about the Apaches, I came across one of Mr. Holmes’ stereoscopes in a consignment shop, by chance, along with several miscellaneous cards. I bought the whole kit and kaboodle. Then I duplicated the photos of the cards in the book, taped them to cardboard backings, put one in the stereoscope and bingo! I could see it in 3-D.
An added note: I meant to put the name of the book that had the stereoptic images such as this one:
On the back of each home-made stereoptic card I dutifully wrote H-16, the code for the yellow bibliography card. I even included their page numbers. I went to my card file, and of the 103 bibliography cards in the drawer, H-16 is the only one missing. I have no idea what I did with it. I was tempted to skip mention of the biblio ID altogether, but reconsidered.
A word to the wise research organizer… if you use bibliography cards, keep them together. You never know when they’ll be needed again, even after years have passed.