Over the course of several millennia, humans learned how to make that reflection portable, first by polishing stone and metal, then by bonding a metal to the back of a clear glass or plastic. As the reflections became clearer and brighter, mirrors were applied to more than self-inspection: for extended vision, via periscopes, telescopes, microscopes, and cameras; for communication, via heliographs, photophones, and the mirror galvanometers of undersea telegraph cables; for amusement, via kaleidoscopes and stage illusions; for energy, via solar furnaces and sunlight-propelled spacecraft; and for other purposes, via many additional ingenious devices. This book presents the story of the construction and use of mirrors for work and play.