Kaleidoscopes are well known to many students and parents but we were inspired by Doug Goodman to build a big one. Doug has built large kaleidoscopes from dressing mirrors obtained from hardware and home stores that can be quickly taped together. The NES/OSA added a marketing flair by enclosing the mirrors in a jeweled tube, a bedazzled kaleidoscope.
The kaleidoscope was constructed from a 9 inch diameter, 4 foot cardboard tube with three mirrors cut to length and width. The width(W) of the mirrors is calculated from the Law of Sines knowing the inner tube diameter (2R) and the angle (A) between each mirror such that
2R = W / Sin(A)
An eyepiece was made from a spring form cake pan with a hole in the base and another cake pan is used to hold colored beads/foils as target for the kaleidoscope image. Painting the tube and gluing plastic jewels complete the presentation. The tube can be mounted in a stand made of PVC plumbing pipe.
The following illustrations show how the images are multiplied for three and four mirror kaleidoscopes.