Fahrenheit and Celcius

Margaret made me wondering today what does zero degrees Farenheit meant. I knew that 100 was body temperature, but why was 0°F−17.8 °C? It just did not make any sense...

The Wikipedia has a good explanation: Farenheit took 100 as body temperature (or the closest he could measure back in 1708) and zero for the coldest he could find. After much subsequent tweaking, they finally came up with the Farenheit scale still used today (but only in the USofA and Jamaica).

So, boiling is 212°F, body temperature (before reading this post) 98.2°F, paper fire point (when books self ignite) 451°F and -40°F is -40°C.

Here's an alternative explanation:
The Straight Dope: On the Fahrenheit scale, why is 32 freezing and 212 boiling? What do 0 and 100 mean?

"In short, 100 means nothing at all on the Fahrenheit scale, 96 used to mean something but doesn't anymore, and 0 is colder than it ever gets in Denmark. Brilliant."

Quite why the Americans still use Farenheit is like asking why they still use older versions of the imperial measurement system
even long after this meeting in Philly...