Ever wondered what these are?! A motometer was an early external temperature gauge for automobiles mounted on top of the radiator cap to monitor your coolant temperature. It was popular from the 1910s through the 1920s, before in-dash gauges became a standard in cars, and was a must-have accessory to prevent overheating. These devices were initially very basic and utilitarian but soon became decorative, often with brand logos or artistic hood ornaments. #motometer #history #cars #car #classiccar