Final answer:
The two types of barometers are the mercury barometer, which uses a column of mercury to measure atmospheric pressure, and the aneroid barometer, which uses a spring within an evacuated capsule to provide pressure readings.
Step-by-step explanation:
The two different types of barometers are mercury barometers and aneroid barometers. A mercury barometer measures atmospheric pressure by the height of a column of mercury. It consists of a glass tube filled with mercury, inverted in a mercury reservoir. The weight of the mercury column adjusts until it is in equilibrium with the atmospheric pressure and the height of the mercury is then read off a scale.
An aneroid barometer, on the other hand, measures atmospheric pressure without using liquid. It uses an evacuated metal capsule (usually containing a spring), which expands or contracts with changes in pressure. The movement is then amplified and transferred to a dial, providing a reading of the atmospheric pressure.