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A sundial measures time by the position of the sun. The most commonly seen designs, such as the 'ordinary' or standard garden sundial, cast a shadow on a flat surface marked with the hours of the day. As the position of the sun changes, the time indicated by the shadow changes. However, sundials can be designed for any surface where a fixed object casts a predictable shadow.

Most sundial designs indicate apparent solar time. Minor design variations can measure standard and daylight saving time, as well.

History


Sundials in the form of obelisks (3500 BC) and shadow clocks (1500 BC) are known from ancient Egypt, and were developed further by other cultures, including the Chinese, GreekDiogenes Laertius - Anaximander, and Roman cultures. A type of sundial without gnomon is described in the old Old Testament (Isaiah 38:2). *

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Analemmatic Sundials - Descriptions of these vertical post sundials, why they work, detailed account of the maths necessary to plot the hour lines.
Meta Description: [ We've all seen a traditional sundial, where a triangular wedge is used to cast a shadow onto a marked-out dial - but did you know that there is another kind? In this article, Chris Sangwin and Chris Budd tell us about a different kind of sundial, the analemmat... ]

Cadrans Solaire - Describes different types of sundials, has other technical and general information. Offers free Shadows software to compute sundials of a number of different types for anywhere in the world.

Gardens Guide - An essay on the use of sundials in gardens.
Meta Description: [ Sundials connect gardens, and their designers, with the solar system ]

Phil's Sundial Photo Gallery - Includes British and international sundials with description and exact location; sun compasses.
Meta Description: [ Welcome to Phil Walker's Sundial Webpage with photos of sundials , mainly in England, suncompasses and also links to British Sundial Society ]

Solar Time - Heiner Thiessen designs Sundials that can tell the time of Ssunrise and Sunset and tell the angle of Solar declination and even the time at night. This site shows how they work.
Meta Description: [ Solar Time - Unique sundials that tell the time of sunrise, sunset, solar declination and zenith and can tell the time at night and in all time zones around the world simultaneously ]

SUNDI - Sundial Design Software - Shareware / freeware software for design and planning of the most popular dials.
Meta Description: [ SUNDI Design Program - software overview ]

Sundial Design Program - Software to design a vertical (wall mounting) sundial for walls that face up to 60 degrees away from due-south.

Sundial Information - Describes sundial parts and names, the basic types, and has make your own pages for three simple types of dial.

404 Sundials - A page from Jack Aubert, with technical information on construction and placing.

Sundials - Describes the history of sundials, and their development in Europe from the time of the Greeks. Includes literary and poetic references.

500 Sundials in the Czech Republic and Slovakia - On-line catalogue, with facilities for search, adding records, map, statistics, articles and references.
Meta Description: [ Sluneční hodiny v České republice a na Slovensku, Slnečné hodiny v Českej republike a na Slovensku, Sundials in the Czech Republic and Slovakia, Sonnenuhren in der Tschechischen Republik und Slowakei, Cadrans solaires en République Tchčque et Slovakia ]

Sundials on the Internet - A major information source, with projects, detailed technical information, links to related sites, listings of societies.
Meta Description: [ The leading world Internet site on sundials, including sundial makers, books, journals, Sundial Trails all over the world, national societies, sundial projects, and many pictures of sundials. ]

The Analemmatic Sundial - Describes design and construction of a six meter wide analemmatic sundial in Canada.
Meta Description: [ Keppel Henge is a large stone circle which has been created in Canada. This page of the web site describes a special project that took place there. ]

The British Sundial Society - Information on the society, links, beginner's pages, including simple sundial patterns and templates, online facilities to calculate hour lines for different sundial types.
Meta Description: [ The British Sundial Society's home page. ]

404 The Dutch Sundial Society - Information is mostly in Dutch, but with some English language pages, including how to calculate several types of sundial.

The North American Sundial Society - Includes general information, links, a register of dials in North America, and a message board.
Meta Description: [ The NASS site has information on sundials, links, a register of dials and a sundial message board. ]

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