Page "Meniscus" Paragraph 1

The meniscus ( plural: menisci, from the Greek for " crescent ") is the curve in the upper surface of a liquid close to the surface of the container or another object, caused by surface tension.

It can be either convex or concave.

A convex meniscus occurs when the molecules have a stronger attraction to each other ( cohesion ) than to the material of the container ( adhesion ).

This may be seen between mercury and glass in barometers and thermometers.

Conversely, a concave meniscus occurs when the molecules of the liquid attract those of the container's, causing the surface of the liquid to cave downwards.

This can be seen in a glass of water.