Water barometer : A barometer in which the changes of atmospheric pressure are indicated by the motion of a column of water instead of mercury. It requires a column of water about thirty-three feet in height.

Example:


Taxonomy
barometer, aneroid barometer, mercury, atmospheric pressure, mercury barometer, pressure, air pressure, water level, reservoir, body, altitude, low pressure, Patent, measuring instrument, measure, cell, capsule, atmosphere.

Defination from the web:
water, air, or mercury. ... [edit] Water-based barometers ... The largest barometer in the world, Bert Bolle's Water Barometer in the Barometer Tower in ...