The mercury thermometer was invented by Daniel Gabriel Fahrenheit in 1714. He developed the mercury thermometer with a standardized scale, known as the Fahrenheit scale, which he published in 1724. Fahrenheit's invention improved temperature measurement accuracy by using mercury in a glass tube, exploiting mercury's predictable expansion properties. He also assigned key temperature points such as the freezing point of water at 32 degrees and normal human body temperature initially at 96 degrees (later adjusted to 98.6 degrees). Fahrenheit was a Polish-born Dutch physicist who made significant contributions to thermometry and temperature measurement.