Imagine, you are living in the late 1800s. It is a special day today, because your father is bringing home a suprise for the family. You don't know what it will be, but you are looking forward to it. When he arrives home he is carrying a funny shaped package, a shape you've seen before. You hope it is what you think it is, and when he opens it, it is! A stereoscope and a whole collection of stereographs. You've seen them before, but to have one of your own will bring hours of fun.
When I took this stereoscope (viewer) and stereographs (cards) to show the children they were blown away by them. They thought at first that they were 'pretty boring looking' but when they had seen what the stereoscope could do, they changed their minds. One child even told me it was 'the definition of awesomeness!' Stereographs, and the stereoscope viewer, create three dimensional images out of two separate images and to the children this was like magic. To think that such a clever contraption had been created so long ago was very surprising to them, and they wished they were still commonly made today. Many of the children would rather like one of their own.
Stereographic cards, like the ones I showed the children were first developed in the 1840s, but it wasn't until about 1850 that they really captured the publics imagination. In 1850 Sir William Brewster invented a device for viewing the cards to make the images easy to see. It was quite a large device, but it made 'seeing' the pictures much easier. In 1851 stereographs and their viewers were featured in the Great Exhibition, and Queen Victoria was intrigued by them. Her praise of them set them up for a big future and soon, millions of cards were being produced and purchased. Then, an American, Oliver Wendell Holmes invented a hand held viewer for stereographs (like the one I showed the children) and their popularity was assured. They would only continue to increase in popularity over the coming years, before finally being superceded by movies and television.
So, what was so special about stereoscopes. Stereo comes from the Greek word for solid, and essentially means that stereoscopic images, when viewed correctly, appear 'solid' or three dimensional. They use the same principles which the eye relies on to make the 'trick' work. Everyone's eyes are about 2 inches apart, and this means that each eye sees a slightly different perspective. Our brain then processes the images, combines them and creates what you see, a world in three dimensions. You can see this for yourself by shutting one eye, then swapping which eye is shut. The world will seem to move. When you open both eyes again though the images combine. Stereoscopes copy this by taking two images of the same thing, from slightly different perspectives. By using a stereoscope, the images are combined into a single picture which has the illusion of depth, or seems to be in 'three dimensions'. If you would like to learn more about stereoscopes and stereographs, click here.
