You can measure temperature using a thermometer. The temperature is read on a Fahrenheit or a(n) Celsius scale. Air pressure can be measured using a mercury barometer, which has a glass tube with the open end submerged in liquid mercury. The mercury stops rising when its weight equals the air pressure. You also can use a(n) aneroid barometer to measure air pressure. This device is a metal can with most of the air removed. Inside, a(n) spring balances the outside air pressure. A needle indicates the changes in air pressure.