Researched
Barometer
Torricelli's mercury tube (1643) shows that air has weight and lets pressure be measured, the key instrument of weather observation.
Open in the interactive tree →Falling pressure signals storms, so the barometer became the key instrument of weather observation. Combined with the thermometer it made quantitative meteorology possible.
Prerequisites
Unlocks
- Vacuum Pumps & Gas Laws1643-1662
- Weather maps and services1854Pressure readings are the basis of weather observation and weather maps