One of the old, odd and curious devices children had in the 1970's (not just then, but that's when I had one) is the kaleidoscope. I have no idea where mine ended up. It was a cardboard tube with plastic beads inside the end. As you turned the tube the beads rolled around and created different patterns when you looked through the lens at the top. I think it would be related to those keyhole/ pinhole cameras. Do I have that name right? I read about them years ago.
I've seen some variations in kaleidoscope styles. Some have little gems inside, instead of beads, or something else entirely. The one I would have like to buy (and try) was a natural DIY kaleidoscope which you could put anything flat enough to fit in and view it. The ad showed flowers, bits of leaves and other things found outside. Not rocks mostly likely, they would scratch it and be too large to fit. I found several of this kind on Amazon and elsewhere but none were shipped from Canada, or at least from Amazon itself. Also, I thought they should have a nicer wood and finish. They look a bit too cheap, as they are.
Amazon kaleidoscope link.
Vintage kaleidoscopes had interchangeable gears/wheels/discs to switch out. Others I found had a glass marble at the end of the tube, some were able to change those too. Yet more are artsy and individual looking, and even more expensive. What really matters is what you see when you look through.
I want lots of colours and different shapes. A few only had black and white, which was interesting but not as pretty. More colours and, of course, more shapes, will give the kaleidoscope more patterns. If you have one, try to turn the scope just a tiny bit and what the colours and shapes twitch just the least little bit. I would try to keep an eye on one particular bead and follow it.
Life is like a kaleidoscope, a slight change and all patterns alter.
The Brewster Kaleidoscope Society
Kaleidoscope from Wikipedia:
A kaleidoscope (/kəˈlaɪdəskoʊp/) is an optical instrument with two or more reflecting surfaces (or mirrors) tilted to each other at an angle, so that one or more (parts of) objects on one end of these mirrors are shown as a symmetrical pattern when viewed from the other end, due to repeated reflection. These reflectors are often enclosed in a tube, usually containing on one end a cell with loose, colored pieces of glass or other transparent (and/or opaque) materials to be reflected into the viewed pattern. Rotation of the cell causes motion of the materials, resulting in an ever-changing view being presented.
History
Multiple reflection by two or more reflecting surfaces has been known since antiquity and was described as such by Giambattista della Porta in his Magia Naturalis (1558–1589). In 1646, Athanasius Kircher described an experiment with a construction of two mirrors, which could be opened and closed like a book and positioned in various angles, showing regular polygon figures consisting of reflected aliquot sectors of 360°. Richard Bradley's New Improvements in Planting and Gardening (1717) described a similar construction to be placed on geometrical drawings to show an image with multiplied reflection. However, an optimal configuration that produces the full effects of the kaleidoscope was not recorded before 1815.
In 1814, Sir David Brewster conducted experiments on light polarization by successive reflections between plates of glass and first noted "the circular arrangement of the images of a candle round a center, and the multiplication of the sectors formed by the extremities of the plates of glass". He forgot about it, but noticed a more impressive version of the effect during further experiments in February 1815. A while later, he was impressed by the multiplied reflection of a bit of cement that was pressed through at the end of a triangular glass trough, which appeared more regular and almost perfectly symmetrical in comparison to the reflected objects that had been situated further away from the reflecting plates in earlier experiments. This triggered more experiments to find the conditions for the most beautiful and symmetrically perfect conditions. An early version had pieces of colored glass and other irregular objects fixed permanently and was admired by some Members of the Royal Society of Edinburgh, including Sir George Mackenzie who predicted its popularity. A version followed in which some of the objects and pieces of glass could move when the tube was rotated. The last step, regarded as most important by Brewster, was to place the reflecting panes in a draw tube with a concave lens to distinctly introduce surrounding objects into the reflected pattern.
Brewster thought his instrument to be of great value in "all the ornamental arts" as a device that creates an "infinity of patterns". Artists could accurately delineate the produced figures of the kaleidoscope by means of the solar microscope (a type of camera obscura device), magic lantern or camera lucida. Brewster believed it would at the same time become a popular instrument "for the purposes of rational amusement". He decided to apply for a patent. British patent no. 4136 "for a new Optical Instrument called "The Kaleidoscope" for exhibiting and creating beautiful Forms and Patterns of great use in all the ornamental Arts" was granted in July 1817. Unfortunately, the manufacturer originally engaged to produce the product had shown one of the patent instruments to London opticians to see if he could get orders from them. Soon the instrument was copied and marketed before the manufacturer had prepared any number of kaleidoscopes for sale. An estimated two hundred thousand kaleidoscopes sold in London and Paris in just three months. Brewster figured at most a thousand of these were authorized copies that were constructed correctly, while the majority of the others did not give a correct impression of his invention. Because so relatively few people had experienced a proper kaleidoscope or knew how to apply it to ornamental arts, he decided to publicize a treatise on the principles and the correct construction of the kaleidoscope.
More than you wanted to know, but its still interesting to read. The Wikipedia link has more.
Instructables has a fancy kaleidoscope to make. Not one of the simpler cardboard types.
I wonder if there is some kind of digital kaleidoscope? A software program. I didn't look for one, but I'd be surprised not to find something like that.