<http://schema.org/description>
"Sundial, a device used to tell time by the sun. Nearly every sundial has two basic parts: a pointer, called a style or gnomon, which casts a shadow; and a numbered dial on which the shadow falls to show the hour."^^<http://www.w3.org/2001/XMLSchema#string>
<http://science.howstuffworks.com/dictionary/astronomy-terms/sundial-info.htm>