A teleidoscope is a kind of

kaleidoscope A kaleidoscope () 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 regular symmetrical pattern when v ...

, with a

lens A lens is a transmissive optical device which focuses or disperses a light beam by means of refraction. A simple lens consists of a single piece of transparent material, while a compound lens consists of several simple lenses (''elements''), ...

and an open view, so it can be used to form kaleidoscopic patterns from objects outside the instrument, rather than from items installed as part of it. Invented by John Lyon Burnside III and

Harry Hay Henry "Harry" Hay Jr. (April 7, 1912 – October 24, 2002) was an American gay rights activist, communist, and labor advocate. He was a co-founder of the Mattachine Society, the first sustained gay rights group in the United States, as well as ...

, the patent was filed in 1970 and granted in 1972.Telescopic kaleidoscope: US 3661439 A
/ref> Teleidoscopio-1

The lens at the end of the tube is not an optical requirement, but protects the internals of the teleidoscope. A spherical

ball lens A ball is a round object (usually spherical, but can sometimes be ovoid) with several uses. It is used in ball games, where the play of the game follows the state of the ball as it is hit, kicked or thrown by players. Balls can also be used ...

is often used. An advantage of using a sphere is that it will not press flat against the object being viewed, which would block all light and result in no image being seen.

External links

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Kaleidoscopes Periods & Styles
Brewster Kaleidoscope Society

References

Optical toys American inventions Educational toys {{toy-stub