What is the physical markers of the Fahrenheit temperature scale based on?

Question

We all know that the physical markers for the Celsius temperature scale are the freezing and boiling points of water at one atmosphere of pressure equaling 0 and 100 respectively.

So what are the physical markers of the Fahrenheit scale?

Answer 1

Wikipedia has 5 versions of how the scale was developed, 3 of which are recognized as plausible:

1) 0 was the lowest recorded temperature and 100 was blood temp
2) 0 for the point at which salt/ice freezes and 96 for blood temp
3) Used Romer's scale, multiplied by 4 and made some other calibrations

Answer 2

Daniel Gabriel Fahrenheit invented thermometers, that seem to be very little change from the ones we use today. The glass tube type where the liquid expands inside with a numbered scale next to it. So having invented the thermometer, he needed a scale. The easiest way is set a 0 and 100, then divide off the measurements in between. For zero he used the coldest temperature he could produce, salt water at freezing. For 100 he used the body temperature of a horse. Celsius is a lot more useful for everyday use 0 is water freezing point, 100 is water boiling point.

Answer 3

Zero was given to the lowest outside temperature recorded by Fahrenheit over several years, and 100 was given to the highest
outside temperature recorded over the same period of time.

Answer 4

Zero degrees was the lowest temperature he had ever recorded and 100 was his own body temperature but it's suspected he had a fever at the time. Here's a pretty goo write up --

http://en.wikipedia.org/wiki/Fahrenheit

Answer 5

These are the temperautres Fahrenheit recoded when when his thermometer showed those readings.

Answer 6

There are a variety of stories.