The following sections of this BookRags Literature Study Guide is offprint from Gale's For Students Series: Presenting Analysis, Context, and Criticism on Commonly Studied Works: Introduction, Author Biography, Plot Summary, Characters, Themes, Style, Historical Context, Critical Overview, Criticism and Critical Essays, Media Adaptations, Topics for Further Study, Compare & Contrast, What Do I Read Next?, For Further Study, and Sources.
(c)1998-2002; (c)2002 by Gale. Gale is an imprint of The Gale Group, Inc., a division of Thomson Learning, Inc. Gale and Design and Thomson Learning are trademarks used herein under license.
The following sections, if they exist, are offprint from Beacham's Encyclopedia of Popular Fiction: "Social Concerns", "Thematic Overview", "Techniques", "Literary Precedents", "Key Questions", "Related Titles", "Adaptations", "Related Web Sites". (c)1994-2005, by Walton Beacham.
The following sections, if they exist, are offprint from Beacham's Guide to Literature for Young Adults: "About the Author", "Overview", "Setting", "Literary Qualities", "Social Sensitivity", "Topics for Discussion", "Ideas for Reports and Papers". (c)1994-2005, by Walton Beacham.
All other sections in this Literature Study Guide are owned and copyrighted by BookRags, Inc.
The meniscus is the curved, upper surface of a liquid formed when in a tube. The meniscus is produced by surface tension. With some liquids, such as water, the meniscus is concave. This means that the liquid at the edge of the tube stretches up above the surface of the water. Other liquids, for example mercury, have a convex meniscus. With a convex meniscus the liquid stands up away from the bulk of the liquid and there is a gap between the liquid and the wall of the container. These differences are caused by the surface tension and cohesive and adhesive forces that are acting between the liquid and the container.
With water in a glass tube the adhesive forces are greater than the cohesive forces. This means that the water is attracted to the glass and at the edges the water is attracted up the glass wall, rather than being attracted to the rest of the water. With mercury in a glass tube cohesive forces are greater than the adhesive forces. This means that the mercury is attracted to itself more than it is attracted to the glass walls of the tube. This gives the effect of the mercury clumping together so the top of the liquid is a little bump standing upright with as little contact between the end of the mercury and the glass walls as possible.
When the volume of a liquid is being read from a scale the reading should be taken from the bottom of the meniscus to ensure an accurate reading.