The History and Development of Sundials

For Millenia The Sundial Was the Main Instrument for Measuring Time

Apr 1, 2009

Babylonians, Egyptians, Greeks, Romans, Arab and Renaissance scientists all contributed to the development of a scientific instrument unsurpassed until the 19th Century.

For thousands of years people have taken pleasure in the sundial’s combination of beauty and practicality. What better instrument could there be to measure those precious hours spent lazing in the garden?

Sundials in the Ancient World

The earliest sundials were simply shadow stick devices, and the Babylonians and Egyptians built simple obelisks which used the sun to throw a shadow marking the time of day over 4,000 years ago. The Chinese are also believed to have used a form of sundial in ancient times.

Egyptian Sundials

However, it appears to have been the Egyptians who invented the first true sundial in about 1500 BC. This was a simple horizontal bar, with a raised “T” at one end. Set to face east in the morning and west in the afternoon, the time could be told by the length of the shadow along the horizontal bar, which was inscribed with 5 lines to measure the passage of time in units of an hour.

The Egyptians later refined their design to produce a south-facing device which could be used throughout the day without being moved.

They also produced small sundials designed for portable use. Such portable sundials continued to be used throughout Europe until watches became generally available in the 19th century.

Improving the Accuracy of Sundials

Over the ensuing centuries various developments were made to improve the accuracy of sundials: the early bars were replaced in turn by flat horizontal plates, sloping or vertical plates and then hemispherical bowls and half bowls; it was discovered that an angled gnomon or pointer aligned with the axis of the earth threw a shadow which reflected the time accurately regardless of the season; increasing understanding of astronomy and geometry were used to calculate the position of the hour and minute lines, and these in turn were simplified with the invention of trigonometry.

Sundials were used throughout the classical world, but it was the Greeks and later the Arabs rather than the Romans who drove these changes.

Renaissance Sundials

With the Renaissance came the golden age of sundials as a time piece and astronomical instrument lasting from 1500-1800 and a huge variety of different types of sundial were developed. Probably the most elaborate was the armillary sundial, a complex open sphere of arcs, arrows and rings

Even after the invention of mechanical clocks and watches, sundials were for many years more accurate. Well designed ones were accurate to the minute and were used for setting the right time on clocks well into the nineteenth century.

The most sophisticated Renaissance sundials had markings to show the seasons, the date and the and the times of sunrise and sunset.

Modern Sundials

Many sundials from this period can still be seen, not only in museums, but still “functioning” in gardens and on buildings, particularly churches and cathedrals. Many of these classical designs are also still reproduced in the sundials sold today by garden centres and internet suppliers, though normally these are regarded as attractive garden ornaments rather than serious timepieces.

It’s not surprising that sundials are such popular garden ornaments. Including a sundial in your garden design or on a patio can add constant interest as well as a visually attractive feature.

The copyright of the article The History and Development of Sundials in W European History is owned by Tony Allen. Permission to republish The History and Development of Sundials in print or online must be granted by the author in writing.