Sundials

Introduction

Today, most clocks and watches are quartz controlled. And they cost only a couple of euros. Some clocks are even radiographically kept 'up to date'.

Why, then, do those ancient, inaccurate devices fascinate so many people? Which can't even be read at all on cloudy days? Is it because of their decorative, aesthetic appearance? Or their intricate geometric foundation, incomprehensible for the ordinary person, but obviously not so for the right old craftsman?

Anyway, never in history sundials were so widespread as today. Be it that most of them are those dull armillary spheres from the big gardening stores. Which, when installed, may point to any direction but north. "Oh, but it should point to the sun, shouldn't it?"

The earth's rotation has imposed a 24-hour rhythm on all living creatures. This cycle also controls our social life, of daytime action and rest at night (we're talking of the pre-disco era). As the complexity of social life increased, time of day could no longer be indicated by 'morning', 'around noon' or 'evening'. The regular course of the sun along the sky suggested a means to specify the time more precisely, and all sundials use this principle one way or another.

Sundial variations

As the earth's axis is not perpendicular to the plane of the earth's orbit, the sun reaches different altitudes on different days. That's why a sundial may tell the date as well.

The use of sundials is complicated by the fact that the earth's course around the sun is not completely regular, its orbit being an ellipse. Together with the slanting of the earth's axis, this causes the apparent solar time to deviate up to a quarter of an hour from the mean solar time. The difference is called the equation of time, abbreviated EoT.

In addition, the local mean solar time differs from standard (or civil) time, which applies to an entire time zone. In summer, summertime or daylight saving time (DST) may introduce an extra hour difference or so.

Sundials may show the signs of the zodiac, which are related to the sun's declination. Occasionally, signs for the planets may also be seen. You may look them up in the tables provided here.

Finding your way around this site

The classification of sundials contained in the main menu at left may guide you in your visit. The page on classification gives some reasoning behind the choice of just these categories.

When you are looking for a sundial in a specific city, the Index may come in handy. Most entries have keywords added, for instance 'Longwood Gardens' to a sundial near the city of Kennett Square. You may search for such terms with the 'Find in page' option of your browser. Moreover, a list of additional pages is provided, for instance about Piet Hein, the inventor of the helical dial (??). The index pages are only available when your browser enables frames.

Sundial data

I have provided a couple of basic data with each sundial, insofar as I could find them: its code in a national catalogue or registry, the location, the designer and the inauguration date. Many data are still lacking, however, and any additions are appreciated.
If no country is given, the Netherlands is meant.

Catalogues or registries have been published for several countries (see the listing). I had access to:
- Netherlands: "Zonnewijzers in Nederland" (ZiN) with the "Supplement" (Sup)
- Belgium: "Zonnewijzers in Vlaanderen" (ZiV)
- Germany & Switzerland: "Sonnenuhren Deutschland & Schweiz" of the Deutsche Gesellschaft für Chronometrie (DGC)
- USA & Canada: "Registry" of the North American Sundial Society (NASS), also available on the Internet.

Disclaimer

My comments tell what I like of the dials presented here, but also what I don't like, or what I think is wrong. Indiscriminate applause doesn't develop insight and appreciation, and that's exactly what this site wants to do. It is not at all my intention to blame the designer or the maker of any dial. I am very well aware how much devotion, motivation and all kinds of skills are needed for the actual production of a sundial. And I also know how badly practical problems and limitations may affect a wonderful idea.

Most pictures on this site are mine. Occasionally I 'borrowed' pictures to illustrate important points in my story, trying to acknowledge the source in all cases. If you nevertheless think your interests are harmed, let me know; that's unintentional.

The English version of this website is intended for those visitors who don't read Dutch easily. However, English is not my native language, so please be considerate. Of course, constructive criticism is welcome.

Thanks to

Many people have contributed to the development of this website, by contributing hints, ideas, pictures or via discussions. I hope they like the result.
In particular I am most grateful to Willy Leenders from Hasselt (Belgium) for his continuous interest and support. I thank Fer de Vries, secretary of the Dutch Sundial Society, for his insightful comments.