Gary’s Q&A

Listener question & Gary’s response · Transcript passage

Davan Woolley asks, Hadrian’s wall is 73 miles long what would that be in Roman miles? What’s the difference?

Good question, Davan.

A Roman mile is close to the imperial mile that we still use in the US and the UK. In fact, the imperial mile was based on the Roman mile.

The Roman mile was called a mille. In Latin, mille is just the world for one thousand.

The Roman mille came from the fact that it was measured to be 1000 paces. The Romans measured a pace by the number of times your left foot was set down. We might measure a pace as one step, but the Romans would have measured it with two steps.

As you can probably guess, this was a very inaccurate method of measurement. The length of the mille was based on the length of a pace, which depended on the person’s stride.

Agrippa, the number two guy to Augustus on whom I’ve done a previous podcast, standardized the Roman foot to….his foot. He also defined a pace as five feet, which made the Roman mile 5000 Roman feet.

It is believed, based on distances between Roman mile markers, that the Roman mile was 91.9% of an imperial mile. So, Hadrians Wall would be 79.4 Roman miles.

In England, the old mile was based on 5000 feet, but they had a different definition of a foot. Under Queen Elizabeth I they modified the mile to being eight furlongs which ended up being 5,280 feet. The change was made for tax reasons.

The origin of Imperial Units should probably be its own episode because all of the units have such a bizarre origin.