A coworker and I were just talking about the confusion in our country between English (aka Christian) and Metric (aka Heathen) units. I fell solidly in the heathen camp, as I much prefer working in Metric units. I’m slowly learning to think in those units, as well.
Our conversation predictably devolved into wondering what the hell ol’ Danny Fahrenheit was smoking. Celsius is based on the freezing and melting points of NIST-traceable water. What is Fahrenheit based on? I remembered learning this at some point, but those brain cells had long ago been consumed by delicious (or, occasionally, not so delicious) alcohol. After a bit of research, I have learned the story behind the confounding Fahrenheit scale.
So, in 1724 Daniel Fahrenheit proposed a temperature scale he “developed”. He “developed” it off of three reference temperatures — brine, ice and blood. The brine was a 1:1:1 mixture of ice, water and ammonium chloride. It stabilized its temperature very quickly and made a good first point. The ice point was measured in a 1:1 ice water mixture. Blood, I can only assume, was the blood of a virgin which was later burned on an alter to Abaddon.
Why the quotes around “developed”? The scale is derivative of work by Ole Rømer. The Rømer scale, which we don’t even bother teaching our offspring about any more, placed the brine temperature at 0, body temperature at 22.5, and water boiling at 60. Fahrenheit took the Rømer scale and multiplied the body temperature and boiling point of water by 4 to get more granularity and to eliminate fractions. Then, he recalibrated the scale so that ice would freeze at 30 and body temperature would be 90. THEN, he changed those to 32 and 96 semi-arbitrarily so there would be 64 divisions between them making it easier for him to mark a thermometer. By this scale, the boiling point of water was about 212 degrees. Later scientists would monkey with the already monkeyed scale so that the boiling point of water is exactly 212 degrees to make 180 divisions between the freezing and boiling point of water.
If you went all tl;dr on me with that, the bottom line is Daniel Fahrenheit stole a temperature scale then engaged in some heavy drug use to come up with a temperature scale that is almost but not quite like the one we use today because some other dudes were mixing crystal meth and decided to change it up even more.
Meanwhile, Anders Celsius just shook his head and laughed.