I've been doing some watch shopping, and I discovered a nifty little feature called a tachyometer (or tachometer). It is used to measure a unit of length (such as a kilometre) by calculating the time it takes to travel that length. Km to km/h.
Made by legowiz55. Remix if you want. I will probably update this with higher accuracy, but this is just to show how a tachyometer works.
