Identify these tubular objects, of which the viewer looks through one end and can see a pretty image, popular as children's toys.
Patented in 1817, a year after its invention by David Brewster in connection with his research on the polarization of light, this device's name comes from the Greek for "beautiful form watcher". One usu- ally contains two or three mirrors which create rotationally symmetric images of colored objects within, and liquid can be added for even more variable effects. Identify these tubular objects, of which the viewer looks through one end and can see a pretty image, popular as children's toys.
Patented in 1817, a year after its invention by David Brewster in connection with his research on the polarization of light, this device's name comes from the Greek for "beautiful form watcher".
kaleidoscope