Could've sworn I remember hearing in grade school that one of then was actually calibrated with cow body temperatures. Don't remember which scale, though.
Where it comes from, I think, is that cow body temperatures are about 100°F, and someone assumed that the scale must have been calibrated using 0° and 100° as specific endpoints.
According to Wikipedia, Fahrenheit seems to have chosen 32°F as the reference point for the freezing of water [it's not clear why this number specifically], and found the body temperature of a human to be 64° more than 32°F [i.e., 96°F]--it being much easier to divide a unit distance in 64 = 2⁶ than to divide it in 100ths.
That does bring up an interesting point, though: while we modern people may think of the metric, base-10 system as being much easier to work with since it's all about lopping off digits, trying to divide a unit length into tenths with high precision is actually far more difficult than halves or thirds. This is why pretty much every customary system involves a lot of units that are twice or three times the next smaller unit. The metric system isn't really feasible until you get the dividing engine [1], which doesn't show up until about the 1760s.
> This is why pretty much every customary system involves a lot of units that are twice or three times the next smaller unit.
I think easily of units that step up by a multiple of 6 (inches and the various time steps), but nothing immediately occurs to me where one unit is directly twice or thrice another. (Oh, except tablespoons, which are three teaspoons.) What examples am I missing?
Where it comes from, I think, is that cow body temperatures are about 100°F, and someone assumed that the scale must have been calibrated using 0° and 100° as specific endpoints.
According to Wikipedia, Fahrenheit seems to have chosen 32°F as the reference point for the freezing of water [it's not clear why this number specifically], and found the body temperature of a human to be 64° more than 32°F [i.e., 96°F]--it being much easier to divide a unit distance in 64 = 2⁶ than to divide it in 100ths.
That does bring up an interesting point, though: while we modern people may think of the metric, base-10 system as being much easier to work with since it's all about lopping off digits, trying to divide a unit length into tenths with high precision is actually far more difficult than halves or thirds. This is why pretty much every customary system involves a lot of units that are twice or three times the next smaller unit. The metric system isn't really feasible until you get the dividing engine [1], which doesn't show up until about the 1760s.
[1]