Shortly after the French-Brazilian aeronaut Alberto Santos-Dumont became the first European to achieve sustained flight in 1906, he complained to his friend Louis Cartier that he didn’t want to be fumbling for his pocket watch to measure time in the air. In response, the legendary jeweler invented a small clock to be worn on a leather strap, one of the earliest wristwatches for men.
It was square.
Such pilot watches became popular in the early 20th century, but eventually they took on a round shape—like the dials and gauges in a plane’s cockpit. The technology that makes clocks and pocket watches work