G. Fahrenheit

Gabriel Fahrenheit is often considered the father of modern Thermometers. His life spanned only a few short years, but his accomplishments were lasting. They are:

The creation of the mercury thermometer. Fahrenheit saw that Galileo and Amonton's  thermometers used alcohol to tell temperature. But alcohol was not the ideal way of measuring temperature. As temperature rose, the alcohol expanded. Alcohol was also too easily thrown off by changing air pressures. It just so happened that mercury expanded at a more constant rate than alcohol, and this was the reason Fahrenheit, used it in his thermometer. Also, mercury was able to be read at either high or low pressures, making it much easier to use in a thermometer.

Another one of Fahrenheit's great ideas, had to do with the simple boiling and freezing points of water and the body's average temperature. It was common in the 18th century for scientists to set the temperature of the average temp. of the human body at 22.5' and the low point at which water freezes at 7.5'C. Fahrenheit, with his newfangled mercury thermometer, opposed these temperatures. Instead he split each degree into four, making water's freezing point at 30'F and the temp. of the body at 90'F. Those degrees were changed in 1717 to 32'F and 96'F to eliminate fractions. Fahrenheit performed many experiments on the boiling point of water, and found that there was a constant, but water's boiling point could change as atmospheric pressure decreased. After years of research, Fahrenheit placed water's boiling point at 212'F, which was actually several degrees too low. But his temp. of boiling water was adopted a few years after his death, by scientists and was adjusted slightly to accommodate change. Now with water's new boiling point at 212'F and its freezing point at 32'F, the average temperature of the human body was placed at 98.6'F.