Fahrenheit is a thermodynamic temperature scale, where the freezing point of water is 32 degrees Fahrenheit (℉) and the boiling point 212℉ (at standard atmospheric pressure). This puts the boiling and freezing points of water exactly 180 degrees apart. Therefore, a degree on the Fahrenheit scale is 1/180 of the interval between the freezing point and the boiling point of water. Absolute zero is defined as -459.67℉.
A temperature difference of 1℉ is the equivalent of a temperature difference 0.556℃.
Rømer is a temperature scale named after the Danish astronomer Ole Christensen Rømer, who proposed it in 1701. In this scale, the zero was initially set using freezing brine. The boiling point of water was defined as 60 degrees. Rømer then saw that the freezing point of pure water was roughly one eighth of the way (about 7.5 degrees) between these two points, so he redefined the lower fixed point to be the freezing point of water at precisely 7.5 degrees. The inventor of the Fahrenheit scale Daniel Gabriel Fahrenheit learned of Rømer's work increasing the number of divisions by a factor of four and establishing what is now known as the Fahrenheit scale.