Anyone who’s ridden modern elevators has Alexander Miles to thank for the stair alternative’s automatic doors. Prior to his design’s 1867 patent, riders had to manually open and close two sets of doors when entering and exiting elevator cars. If a passenger happened to forget to close one of the doors, subsequent elevator riders risked a potentially fatal fall down the elevator shaft. Because, as the adage goes, necessity is the mother of invention, Miles created a mechanism that forced both elevator doors to close simultaneously, thus preventing dangerous accidents.

Per: History