Magic Mirrors - Page 1
Twenty years ago I saw the nearest thing I can describe to pure natural "magic". I was talking to Bill Coates, the senior demonstrator at the Royal Institution in London, and he was holding an object that looked a bit like a small crepe pan.
It was a metal disk a few inches in diameter, with a handle. In fact it was a bronze mirror with a surface so highly polished we could see our faces in it. On the back was an oriental picture in low relief. Bill struck an open carbon arc ( he just loved doing that kind of thing) and moved about twelve feet away. He reflected the light from the mirror onto the white wall of the lecture theatre.
There in front of me was a large image of the Buddha. Later, when I took a close look at the surface of the mirror, I could find no tell-tale signs of any such image.
I've been fascinated by Magic Mirrors ever since that day.
Magic Mirrors come from China and Japan. They became popular in Europe in the early part of the 19th century and many distinguished scientist have attempted to explain the phenomenon. Here are some images from the mirrors in my collection.
Although this is from a modern mirror, this is exactly the sort of image Bill Coates showed me, 20 year ago. Note that this is the image produced by the mirror - there is no image visible at all on the reflecting face of the mirror.
Superficially there seem to be two kinds of magic mirror, those which produce images similar to the relief patterns on their backs, thus giving the illusion of being "transparent", and those which produce a totally different image from the relief on the back. This difference may be just a deception. It may also explain why there are so many theories about how they work, how they are (were) made and how the effect can be recreated "on the kitchen table".
In this particular case, the design on the back of the mirror (shown on the right) is exactly the same as the image projected by the face of the mirror (on the left).
These are "modern" mirrors, in that they have been made recently, unlike the mirror I saw at The Royal Institution. To make these images we used a 150 watt quartz iodine lamp placed about six inches behind an aluminium foil screen, in which we had made a small hole with a pencil. We fixed each mirror in an upright position about six feet (two metres) away from the light source and projected the images onto a white screen quite close to the mirror. After a little experimenting this seemed to give the sharpest picture with adequate brightness to get an exposure reading.