The first barometer, known as the Torricelli's tube, was invented by Evangelista Torricelli. Today there are two types of barometers: the aneroid barometer and the mercurial barometer. Torricelli invented the mercurial barometer.
Torricelli was born in Faenza, Italy in 1608 and moved to Florence, Italy in 1641 to assist Galileo, the famous astronomer, with vacuum experiments. It was Galileo who suggested Torricelli use mercury in his experiments. Torricelli discovered that mercury rises and falls when atmospheric pressure changes.
The aneroid barometer was invented in 1843 by Lucien Vidie. Aneroid barometers do not contain fluid and rely on phosphor bronze or beryllium copper to measure atmospheric pressure.