Answer:
The basic construction, unchanged since Torricelli's experiment in 1643, is a glass tube about three feet long, closed at one end, filled with mercury, and inverted with the open end immersed in a cistern of mercury.
Because they come came out of the same thing so duh
Surface tension could be defined as the property of the surface of a liquid that allows it to resist an external force. The cohesive forces among liquid molecules are responsible for the phenomenon.
In simpler terms, it is the force that causes the molecules on the surface of a liquid to be pushed together and form a layer. The surface tension, then, is a measure of the cohesive forces that hold the molecules together.
Getting the actual measurement would give us 72 dynes/cm at 25°C . However, the force decreases significantly depending on the temperature.