What is a baromeater?

Answer 1

A barometer measures atmospheric pressure. The air in the atmosphere exerts a force called pressure that constantly changes due to moving weather systems. Therefore, in conjunction with other meteorological instruments, a barometer helps to predict clear or rainy weather.

In 1643, Evangelista Torricelli invented the first barometer. He figured that if he had a vacuum, an airless space, he could compare the ever-present atmospheric pressure with zero pressure. So he placed a vacuum contained in a glass tube on top of a larger container of Mercury. The air presses down on the mercury's exposed surface and pushes it up into the tube. The higher the mercury level, the greater the air pressure. Originally, the units of air pressure were just millimeters of mercury. People could finally measure the force of air