vigesimal

This may mean that the people who lived in what is now France used a base-20 or vigesimal number system.

As the latter is due to finger-reckoning, so the use of the fingers and the toes produced a vigesimal scale.

This long cycle was an application of the vigesimal system to their reckoning of time.

I am inclined to think with Dr. Förstemann that it was rather in consequence of the use of the vigesimal system in representing numbers.

A pure quinary or vigesimal number system is exceedingly rare; but quinary scales certainly do exist in which, as far as we possess the numerals, no trace of any other influence appears.