We just learned about the Oil Well.
One part of drilling oil out of the ground is a thing called a Pumpjack.
This is a machine that has a long metal beam hooked up to a machine that pushes and pulls the jack up and down almost like a see-saw.
The pumping motion helps pull the oil out of the ground so it can be collected and taken somewhere to clean up and be used for other things.
(from: wikipedia - pumpjack)
Kid Facts - Blast from the past: Starter