In the 19th century the Dutch scientist and meteorologist, Buys Ballot, produced a law based on the observation of wind direction and pressure systems.
Buys Ballot’s Law states that:
If an observer stands with his back to the wind in the Northern Hemisphere then the low pressure is on his left. (In the Southern Hemisphere low pressure is to the right.)
This law will prove to be a useful tool in both the study of wind and altimetry.