There have been so many technological advancements in the past century that its sometimes hard to keep track.

Inventions seem to come and go, especially in the digital age. But a few devices have stood the test of time. Like the odometer. This device was invented back in 15 BCE by the Roman engineer Vitruvius. He rigged up a chariot wheel with a feature that would drop a pebble into an attached box after the wheel had turned 400 times, which was exactly a mile. At the end of a trip, the driver could determine the distance traveled by counting the number of pebbles that had dropped into the box.

Keep track of how far you’ve come today on National Odometer Day