Kiteman writes -

“About 300 years ago, Daniel Fahrenheit made and calibrated the first reliable thermometers. Some people* still use the scale he developed; the Fahrenheit Scale.” – Link.

Related:

• LED Temperature thermometer project – Link.
• HOW TO – Make an AVR-Based statistics thermometer – Link.
• HOW TO – Make a digital thermometer – Link.
• HOW TO – Make a DVD-thermometer – Link.