Time Off the Wrist: Stonehenge

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We here at worn&wound are used to constantly thinking about time–after all, timekeeping is our business. However, the way in which most of us usually think about time is pretty limited. While mechanical and quartz watchmaking are obviously our most immediate, intimate connection to time in the modern world, man’s relationship with time far precedes the advent of the mechanical clock. As the great American poet Delmore Schwartz wrote, “Time is the fire in which we burn,” and that fire has been burning since the dawn of the universe.

In this new series, “Time Off the Wrist,” we’ll be taking a look at some of the more unusual ways time has been kept through the ages–both clocks and otherwise.

It’s a well-established fact that many ancient structures were built to align with the sun during the solstices. The Great Pyramids of Giza, for example, are precisely lined up to measure the changing of the seasons, but very few of these recorded time with any more accuracy than this. However, one of the most mysterious monuments of antiquity not only tracked the solstices, but it also kept a complete set of solar and lunar calendars as well. That monument, the famous Stonehenge in Wiltshire, England, was perhaps the most accurate timekeeper of the ancient world.

Stonehenge (via TimeLapse.Pro)




The real significance of Stonehenge remains shrouded in mystery. Constantly rebuilt and expanded during its 1,500 years of use, theories about the site have ranged from Arthurian tales of Merlin enslaving a giant to lay the standing stones for magical purposes; to less fanciful modern ideas of a ceremonial burial ground and “land of the dead,” an endpoint for ritual journeys across the English countryside, or even a prehistoric health spa.

Whatever brought the prehistoric Celts here in 3,100 BC, one of the first segments of the henge to be completed were the Aubrey Holes, a series of 56 shallow pits just inside the outer berm. After proper setup aligning the marker to the current declination of the sun and moon, a marker could be moved by two pits each day to complete a 28-day lunar month. At the same time, having 56 holes instead of simply 28 also allows the Aubrey Holes to be used as an annual solar calendar–a separate marker, moved by two holes every thirteen days, would account for a full solar year.

Two final, even slower markers would be moved by just three holes a year. These, in conjunction with the sun and moon markers, would allow for easy prediction of the occurrence and location in the sky of lunar eclipses. Whenever the sun and moon markers were directly opposite each other in the circle of Aubrey Holes, and the two eclipse markers were in the same opposing holes, the early timekeepers at Stonehenge could guarantee a lunar eclipse, an event of great ritual significance to many cultures.


The Aubrey Hole calendar apparatus is remarkably accurate for its age and simplicity, but with an impressively long cycle: in order for an eclipse to occur along the same calendar date and lunar azimuth, the Holes have to complete a complete circuit of 18.61 years.



Later developments to the site further enhanced Stonehenge’s timekeeping ability. The solitary Heel Stone, viewed from within the Aubrey Hole circle, would be the rising point for a lunar eclipse once every 56 years. In addition, if viewed from within the iconic sarsen stone circle, the Heel Stone would be the point at which the sun rose on the date of the summer solstice, an incredibly important date in the year of a Bronze Age farmer.

Celebrating the Summer Solstice.

While clearly not the only reason for its construction, Stonehenge’s astonishing accuracy as an astronomical calendar remains one of its most fascinating aspects. The ability to track lunar, solar, and eclipse calendars make this perhaps the world’s first multi-calendar complication–even if it is a bit less refined than a Patek.

Images courtesy of English Heritage.



Hailing from Redondo Beach, California, Sean’s passion for design and all things mechanical started at birth. Having grown up at race tracks, hot rod shops and car shows, he brings old-school motoring style and a lifestyle bent to his mostly vintage watch collection. He is also the Feature Editor and Videographer for Speed Revolutions.

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