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, depending on the liquid and the surface.A convex meniscus occurs when the particles in the liquid have a stronger attraction to each other (cohesion) than to the material of the container (adhesion). Convex menisci occur, for example, between mercury and glass in barometers and thermometers. Conversely, a concave meniscus occurs when the particles of the liquid are more strongly attracted to the container than to each other, causing the liquid to climb the walls of the container. This occurs between water and glass.