Boiling Point

Run the night shift at an oil refinery. Heat the crude oil so it evaporates, then watch the vapour rise up a cutaway fractionating column that is hot at the bottom and cool at the top. Each hydrocarbon condenses on the first tray that is cooler than its boiling point: open the right valve before it gets there, fill the fractions and send out fuels and feedstock for the petrochemical industry.