Editing Sundial (section)

===Sundial cannon===
{{main|Sundial cannon}}
A [[sundial cannon]], sometimes called a 'meridian cannon', is a specialized sundial that is designed to create an 'audible noonmark', by automatically igniting a quantity of gunpowder at noon. These were novelties rather than precision sundials, sometimes installed in parks in Europe mainly in the late 18th or early 19th&nbsp;centuries. They typically consist of a horizontal sundial, which has in addition to a [[gnomon]] a suitably mounted [[lens (optics)|lens]], set to focus the rays of the sun at exactly noon on the firing pan of a miniature [[cannon]] loaded with [[gunpowder]] (but no [[round shot|ball]]). To function properly the position and angle of the lens must be adjusted seasonally.{{citation needed|date=June 2013}}