<p>
	The barometer is an instrument for measuring atmospheric pressure.&nbsp; The first barometer was invented in the mid-17th C but it did not become a household item before the early 19th C. Although early barometers existed also in water and gaz it is the mercury barometer&nbsp; that is the most common.&nbsp; The antique barometer to be hung on the wall is usually in a richly decorated mahogany or rosewood case which contains both a barometer and a thermometer.&nbsp; The ship barometer is usually in a round case in brass.</p>