The Fahrenheit scale, which measures temperature, was created by Daniel Gabriel Fahrenheit (1686-1736), a German-Dutch scientist, in 1724. He devoted much of his life’s work to the measurement of temperature, and also invented the alcohol and mercury thermometers. On the Fahrenheit scale, the point at which frozen water melts is 32°, and the point where at which it boils is 212°. Between these two points is exactly 180°, a number easily divisible on a thermostat. Although we know with a degree of certainty what measurements the scientist used to determine his scale, his process of arriving at the final scale is largely unknown.
Several stories have circulated regarding how Fahrenheit devised his scale. One is that he established 0° as the coldest temperature he could measure outdoors during the winter of 1708 to 1709 in Danzig (Gdańsk), Poland. This measurement and his own body temperature, which he measured at 100°, were the two marks on which he based the rest of his scale. Many think that either his thermometer was off or he was running a fever that day, resulting in the relatively high reading on the bodily temperature. The scale was then divided into 12 separate segments, which were later divided into eight, creating a scale of 96 separate degrees.
In another story, Fahrenheit figured 0° by taking a measurement of the point at which equal parts of salt and ice mixed together melt. He then established 96° as the blood’s temperature. Yet another story holds that he co-opted Ole Rømer’s scale of temperature. With this scale, 7.5° is the freezing point of water. Fahrenheit multiplied this number to get rid of the fractions, and then refigured 32° as water’s freezing point, with 64 degrees separating the body’s temperature at 96°. He then marked degrees using six lines.
Some believe that Fahrenheit was a Freemason, and because there are 32 degrees of enlightenment, he chose to use 32 as the melting temperature of water. Degrees are also used as levels with the Freemasons, hence the use of the word on the scale. However, there is no documented evidence that the scientist was a Freemason.
In yet another story, it is said that Fahrenheit believed that a person would freeze to death at 0° and would die of heat stroke at 100°. This created a scale of 0° to 100° that encompassed the range of livable temperatures. Another story states that he recorded the melting point of water, the boiling point and a human’s body temperature, and then put the melting and boiling points exactly 180 degrees apart. One far fetched story says that Fahrenheit observed the melting point of butter as 100° and set it accordingly.
Because Fahrenheit degrees are 5/9 of a Celsius degree, it is easier to make more exact measurements without using fractions in the Fahrenheit scale. This scale continues to be used in the United States, although most other countries that use the metric system changed to Celsius in the 1960s and 1970s.