When you were a child, did you have kaleidoscope? You know, that cylinder with the pearls on one side which, when the cylinder is turned, form myriads of symmetrical patterns in never-ending succession…
Kaleidoscopes were invented (or discovered?) by Scottish scientist Sir David Brewster in 1815, while researching optics and polarisation. Nothing more than plane mirrors in a dark tube with a box of beads on one side and an eyepiece on the other, the kaleidoscope became extremely popular at the time, amongst children and adults alike.
While this beautiful toy is all but extinct in the West, superseded by video games and smart phones, kaleidoscopes seem to be still very popular in Japan. I have seen many toy booths at local matsuri, where kaleidoscopes are sold, often in a tiny size, to be dangling from a smart phone. In Japanese, kaleidoscopes are called mangekyo, the three kanji (万華鏡) literally mean ten thousand flower mirror.
In Kyoto, there is a museum devoted to kaleidoscopes. Even though it is very small – only two rooms, one of them the shop – it boasts many interesting exhibits. Altogether, the museum owns about 150 different kaleidoscopes of all sizes, and some 50 are on display at any given time. Once the excitement of looking through them has worn off a little, you begin to pay attention to their outside; and all of them have been expertly handcrafted. There are the usual paper tubes, kaleidoscopes in Tiffany glass, with strips of cloth instead the beads…
As a recovering scientist, I found it a bit disappointing that the technical aspect of how kaleidoscopes actually work was only very briefly explained, and that only in Japanese. But even so, what’s going on inside the cylinder is not hard to grasp, and even if you do not, it does not diminish the beauty of the toy.
The museum is well worth a visit. Once an hour, there is a video projected onto the walls of the exhibition room. In the shop, you can buy kaleidoscopes of all sizes and qualities, and there are even DIY kits to make your own. Unfortunately, you are not allowed to take photos of the exhibits, but postcards are sold portraying some of them.
The museum: http://k-kaleido.org/e-information/
Book about the Kaleidoscope by Sir David Brewster, from 1858: The Kaleidoscope, its History, Theory, and Construction