> the celcius was based off the freezing and boiling point of water at sea level These are not particularly great choices. Water transitions to a solid when i

> the celcius was based off the freezing and boiling point of water at sea level These are not particularly great choices. Water transitions to a solid when it freezes, and distance from sea level has a massive impact on the boiling point of water which Celsius did promptly characterize. Also, somewhat weirdly, Celsius used to be inverted, with 100 being freezing and 0 being boiling.