Barometer Marine Case:
What is a barometer?
The barometer is an instrument for measuring atmospheric pressure, used especially in weather forecasting. Because atmospheric pressure changes with distance above or below sea level, a barometer can also be used to measure altitude. An aneroid barometer indicates pressure on a dial using a needle that is mechanically linked to a partially evacuated chamber, which responds to pressure changes. It was invented in 1643 by the Italian scientist Evangelista Torricelli, who used a column of water in a tube 34 ft (10.4 m) long. Fishermen are keen strategists using a barometer to determine fish behaviour trends.