It happened 375 years ago. Evangelista Torricelli, a student of Galileo, invented the mercury barometer in 1643. And surprisingly, it was amazingly similar to the mercury barometers in use today.

It happened 375 years ago. Evangelista Torricelli, a student of Galileo, invented the mercury barometer in 1643. And surprisingly, it was amazingly similar to the mercury barometers in use today ...

1644: Italian physicist Evangelista Torricelli demonstrates the principles of the mercury barometer, an instrument he invented the previous year. In 1641, Torricelli was working as an assistant to ...

It's possible to build a water barometer on the same principle. But since water is less dense than mercury, atmospheric pressure will push water higher up to about 34 feet. But no higher than that.

Thanks for your question Gordon! A barometer acts like a scale. In a mercury barometer, it measures the pressure of the atmosphere around you and pushes it against the liquid mercury.