Definition

1. Noun:
   • A barometer that measures atmospheric pressure by the height of a column of mercury: A mercury barometer is a scientific instrument used to measure air pressure. It consists of a glass tube filled with mercury, inverted into a reservoir. The height of the mercury column in the tube changes with atmospheric pressure, providing a measurement.

Usage Examples

• Noun:
  • The scientist checked the mercury barometer to predict the approaching storm.
  • Traditional weather stations often used a mercury barometer for accurate pressure readings.

Advanced Usage

• Historical and scientific context: The mercury barometer was invented by Evangelista Torricelli in 1643. It is a classic example of a scientific instrument where a liquid column balances the weight of the atmosphere.
  • The experiment demonstrated the principle behind the mercury barometer.

Variants and Related Words

• Barometer (n): A general instrument for measuring atmospheric pressure.
  • An aneroid barometer uses a sealed metal cell instead of liquid.
• Manometer (n): An instrument for measuring pressure, often of gases, using a column of liquid.
• Mercury (n): A heavy, silvery metallic element (Hg), which is the fluid used in this instrument.

Synonyms

• Hg barometer: A technical synonym referencing the chemical symbol for mercury.

Notes on Meaning

• The term specifically refers to the use of mercury as the working fluid. Other barometers, like aneroid barometers, do not use liquid and function differently.
• Due to the toxicity of mercury, these barometers are less common in modern settings but remain important for calibration and historical study.

Noun

1. barometer that shows pressure by the height of a column of mercury