The temperature scale still in use in the United States (while the rest of the world uses the metric system of Celsius), is named after German engineer and physicist Gabriel Fahrenheit (1686–1736). Fahrenheit developed his scale after visiting Danish astronomer Ole Christensen Rømer (1644–1710) in 1708. For his experiments, R0mer was using an alcohol thermometer upon which he had marked a scale from zero degrees (the lowest temperature he could achieve in his laboratory using a mixture of ice, water, and salt) to 60 degrees, the boiling point of water. This system actually mimics the basic idea behind the Celsius scale.

While Fahrenheit left no records as to why he chose certain high and low points on his thermometers, there has been speculation on this matter. It is known that he used his own body temperature as the high point on his thermometer, but he marked this temperature as 96 degrees. Some believe he chose this number because it was easily divisible by twos and threes. For his zero degree mark he used R0mer’s figure. Fahrenheit later determined that water normally froze at 32 degrees on his scale and boiled at 212 degrees.