Look around sunny Colorado and you’ll see loads of sundials, from Denver’s City Park to the Steamboat Springs library to your neighbor’s garden. They’re more than just decorative antiques, and easier to construct and read than you might think.
The long haul. Widely used by ancient Egyptians, Babylonians and Greeks, sundials have been around since at least 1500 B.C. Along with the hourglass, they were the timekeeping devices of choice during the Dark and early Middle ages.
Shadow play. Horizontal sundials are the most common type. To set them for correct solar time, the gnomon – or pointer that casts the shadow – must be oriented toward true north, not magnetic north, and adjusted to the dial’s geographic location.
Stay sharp. Most store- bought garden sundials in the United States are calibrated for latitude 40 degrees, roughly the latitude running east- west through Colorado at about Denver and Boulder. The most accurate sundials tell standard time to within 30 seconds of a mechanical clock.
Bigger and better. The 85-foot-wide sundial built into the top of the Team Disney office building in Lake Buena Vista, Fla., is believed to be the world’s largest.
Making time. Websites such as mysundial.ca and sundials.org provide simple how-to instructions for home sundials. After you’ve drawn up your plans, build a model to test your design before beginning construction.
Sources: North American Sundial Society (sundials.org), The Sundial Primer, Guinness Book of World Records
