Barometers

Public opinion polls are barometers of confidence in the government.

For instance, gauges, such as thermometers and barometers, are instruments.

The lowest-tuned pipe on the organ set off barometers all over the state.

Is it true that amphibious creatures are barometers or indicators of the health of the planet?

Stock markets are viewed as barometers providing early warnings of future trends in economic activity. If that is so, are the markets telling us that a new recession is around the corner?