Daniel Gabriel Fahrenheit came up with the idea that mercury boils around 300 degrees on this
temperature scale. Work by others showed that water boils about 180 degrees above its freezing point. The Fahrenheit scale later was redefined to make the freezing-to-boiling interval exactly 180 degrees,
[13] a convenient value as 180 is a
highly composite number, meaning that it is evenly divisible into many fractions. It is because of the scale's redefinition that normal mean body temperature today is taken as 98.6 degrees,
[17] whereas it was 96 degrees on Fahrenheit's original scale.
[18]
The
Fahrenheit scale was the primary temperature standard for climatic, industrial and medical purposes in English-speaking countries until the 1970s. The British Meteorological Office officially adopted "Centigrade" — the
Celsius scale — as standard in 1963 but continued using Fahrenheit for public broadcasts into the 1980s. It is presently mostly replaced by the Celsius scale long used in the rest of the world, apart from the United States, where temperatures and weather reports are still broadcast in Fahrenheit