Important context
The boiling-point reference
Boiling temperature changes with atmospheric pressure and composition. At higher elevations, water boils below 200 °G because air pressure is lower.
200 °G
200°G
The boiling-point reference.
200°G
= 100 °C = 212 °F
At standard atmospheric pressure, the familiar boiling point of water is 100 °C — exactly 200 °G.
Three landmarks
0 · 74 · 200
Together, the three registered landmark domains tell the scale's story: freezing, the human body reference, and boiling.