††††The idea of using ball-bearings has been around for thousands of years. About 3000 BC, logs were used with the same principle in mind: to reduce friction between moving objects.
Around 50 AD, the Romans used ball-bearings but they didn't rotate freely. The first time true ball-bearings were used on a vehicle was in 1879 when they were fitted to a bicycle. Today, almost every machine has bearings, including cars, bicycles, electric motors, ship's propellers and even roller skates.
