Answer:
increase in the air pressure
Explanation:
The barometer is a device that is used for measuring the air pressure. It is a device that uses mercury in order to show the air pressure. The mercury reacts easily to the changes in the air pressure, so it is a nice indicator for it. The air pressure can simply be defined as the weight of the air masses, and the pressure they make it because of it on the objects. The lower the air pressure, the higher up the mercury will go, as it will experience less pressure from the air, and the higher the air pressure, the lower the mercury will drop, as it will experience more pressure from the air.
