A barometer measures air pressure it lets you know if the pressure is rising or falling. If it rises it means that is going to be good sunny and hot weather but if it falls it means its going to be bad wet, rough weather. Evangelista Torricelli was an Italian physicist who invented the Barometer.
Measures the amount of water that has fallen over a period of time. Christopher Wren invented the first rain guage.
Determines which way the wind is blowing. Shem Downe inveted it