The aneroid barometer is now a small, inexpensive, robust, accurate, lightweight, and portable instrument. It does away with the delicate glass tubes of weighty mercury and easily overturned reservoirs of the original instrument, relying instead on a sealed bellows-type flexible'" container. This container contracts or expands according to the pressure of the surrounding atmosphere. The pressure is displayed on the dial by a mechanically driven lever or pointer. This dial is usually fitted with a second pointer that can be set manually to indicate the current pressure. Thus the rate of pressure change can be assessed, as well as whether it is increasing or decreasing.
The concept of the aneroid barometer was suggested by Gottfried Wilhelm Leibniz in 1698 but the first working model was made and patented in 1843 by the French scientist and engineer Lucien Vidie (1805-1866). He developed the idea from his work on pressure-measuring manometers on steam-engine boilers. Vidie presented his instrument at the Great Exhibition in London in 1851, when he was awarded a Council Medal. The association between barometric pressure and the weather led to aneroid barometers being purchased by all meteorologists, and they also became part of the equipment of most sailors, explorers, and farmers. At sea the barometer was unaffected by the rocking of the boat.
A barograph is a type of aneroid barometer that records atmospheric pressure over time. It is fitted with inked recording needles and continuously moving recording paper. These usually record the atmospheric pressure for a whole week.
