Measurement of pressure

Barometer is used for the measurement of pressure.
Why mercury is used in barometers?
i) With mercury, practically no vapours are produced
ii) Mercury does not wet or stick with glass
iii) It is shining and opaque, so readings can be easily taken
A gradual fall in the atmospheric pressure indicates a steady increase in the atmospheric water vapour, and rain may occur.
A steady rise in the atmospheric pressure shows a gradual fall in the atmospheric water vapour and indicates a fair weather.
A sudden fall in atmospheric pressure predicts a storm.
The boiling point of a liquid increases with the increase in pressure on its surface.
On higher altitudes, the pressure of atmosphere is less. Thus, water starts boiling below 100 degree Celsius. As cooking temperature of rice, pulses, meat etc. is slightly above 100 degree Celsius, therefore they do not cook well on hills.