Galvanometer is an instrument for measuring electric current.
Gyroscope is a rapidly rotating heavy wheel that keeps the stability of its axis. It was invented in 1852 to demonstrate
Hydrometer is an instrument for measuring the relative density of liquids.
Hydrophone is an instrument for measuring sound under water.
Hydroscope is an optical instrument used for seeing objects below the surface of water.
Hygrometer is an instrument for measuring the relative humidity of the atmosphere.
Hygroscope is an instrument to show the changes in atmospheric humidity.
Hypsometer is an instrument to measure the height above sea level. It is an apparatus for determining the boiling point of liquid. Since the boiling points of liquids have a direct relationship with atmospheric pressure and atmospheric pressure with altitude, therefore, the instrument may be used for the determination of altitude above sea level. This instrument is generally used by the mountaineers.
