How would you explain the behavior when a non-polar liquid displays a convex meniscus?

The meniscus is the curve in the liquid in the upper surface that is caused by surface tension. Water molecules are attracted to the molecules that are in the wall of the container. When the water molecules touch the molecules on the container, that is what forms the meniscus.

When you are trying to measure liquids, you would measure at the bottom of the meniscus. The meniscus can be either concave or convex. The convex meniscus is when the hump is pointed up like in mercury, which is the opposite of concave meniscus which is pointed down like in water.