In 1814, David Brewster had an epiphany: light + casing + mirrors + things to reflect = the most fun ever?
The Scottish scientist—already esteemed for his work in optics—named his invention the kaleidoscope, combining the Greek words kalos (beautiful), eidos (form), and skopeō (to see). He spent two years developing a prototype, and on August 27, 1817, arrived at Stobo Castle in Peebleshire, Scotland, to sign the official patent.
“Any object, however ugly or irregular,” Brewster wrote in the filing, “[when] placed before the aperture…. will coalesce into a form mathematically symmetrical and highly pleasing to the eye.” (Some 150 years later, “first lady of kaleidoscopes” Cozy Baker would demonstrate this point by aiming a teleidoscope—a kaleidoscope with a clear lens on the end—at a plate covered in egg yolks and cigarette ashes. “It came out beautifully,” she declared.)