> 100F was when the thing started to be uncomfortable to touch, I guess?
“Uncomfortable to touch” heavily depends on thermal capacity (how much heat there is in the object to touch) and thermal conductivity (how fast the object can get that heat into your skin), so I would think defining that exact point to be quite the challenge.
“The other limit established was his best estimate of the average human body temperature, originally set at 90 °F, then 96 °F (about 2.6 °F less than the modern value due to a later redefinition of the scale)”
So, Fahrenheit arbitrarily picked 100 °F as some distance above the point for average human body temperature, changed it to 96 °F, and the scale was later redefined.
And still people claim that scale is less arbitrary than Celsius, Kelvin, Réaumur, etc.
“Uncomfortable to touch” heavily depends on thermal capacity (how much heat there is in the object to touch) and thermal conductivity (how fast the object can get that heat into your skin), so I would think defining that exact point to be quite the challenge.
As to the Fahrenheit scale, it’s worse. https://en.wikipedia.org/wiki/Fahrenheit:
“The other limit established was his best estimate of the average human body temperature, originally set at 90 °F, then 96 °F (about 2.6 °F less than the modern value due to a later redefinition of the scale)”
So, Fahrenheit arbitrarily picked 100 °F as some distance above the point for average human body temperature, changed it to 96 °F, and the scale was later redefined.
And still people claim that scale is less arbitrary than Celsius, Kelvin, Réaumur, etc.