Nikola Tesla's patents for aircraft, ships, railways, autos, and more

Speed Indicator

Later in Tesla's life, automobiles gained a surge in popularity -- so much so that it was necessary to know and control how fast you were going in order to maintain safety. As such, several speedometers came into existence, but Tesla created one of the first Speed Indicators that was capable of maintaining accuracy in a wide range of temperatures while still being low-cost.

Image courtesy of Tesla Universe