History

The sundial is one of the human race's earliest achievements in marking the passage of time. But sundials provided people with much more than this practical goal - their replication of the heavens provided aesthetic and religious satisfaction. This is often hard to comprehend nowadays, when sundials have often become little more than garden ornaments and are not usually very accurate (although it is relatively easy to construct an accurate sundial).

THE INDICATOR
ON THE SUNDIAL
IS CALLED A
GNOMON, A GREEK
WORD MEANING
POINTER.

The Egyptians used sundials as early as 1500 BC. A sundial, the dial of Ahaz, is mentioned in the Old Testament (Isaiah 38: 8) and would have existed around approximately 730 B.C. The ancient Babylonians, the Chaldeans, were renowned as astronomers. Their treatises on sundials were the definitive expertise on sundials for over a millennium, until the Christian era.

The Greeks and Romans used sundials extensively. In fact, the indicator on the sundial that casts the shadow is still called by the Greek word "gnomon" which means pointer. The use of towers and obelisks as gnomons to cast shadows indicating the hours, was very evident in ancient Greece and Rome. Sundials were found in houses, tombs, temples, baths and other public places. Not everyone was happy about this as the following quote shows:

The gods confound the man who first found out how to distinguish hours. Confound him, too! Who in this place set up a sundial to cut and hack my days so wretchedly Into small pieces! When I was a boy, my belly was my sundial - one more sure, truer, and more exact than any of them. This dial told me when 'twas proper time to go to dinner, when I had ought to eat. But nowadays, why even when I have, I can't fall to unless the sun gives me leave. The town's so full of these confounded dials, the greatest part of its inhabitants, shrunk up with hunger, creep along the streets.

Attributed to Plautus Oldest known quote on sundials

Later on, the Arabs were renowned for more complicated sundials of greater accuracy and scope of design. Elsewhere on the globe, the Chinese were great users of sundials and the Aztecs and Inca civilizations in the Americas were also familiar with sundials.

The Nocturnal dial was first used in the 15th century by navigators who needed to tell time by the position of the stars. Prior to the early 17th Century, mechanical pocket watches were uncommon, expensive and unreliable. The traveler who wished to keep track of time was forced to rely on a portable sundial. We are told that King Charles I carried a silver pocket sundial, and that on the evening preceding his execution, he entrusted it to his attendant as a last gift to his son, the Duke of York. Henry II was notoriously late for his love trysts with his mistress and eventual wife, Eleanor of Aquitaine (he was usually on a hunt). In 1152 Eleanor had a special, portable sundial created for him so that hešd know when to leave the hunt to meet her. Moved by her love, Henry ordered his court jewelers to create a copy for Eleanor - inlaid with diamonds, rubies, other precious stones, and the words, "Carpe Diem" or "Seize the Day." The Aquitaine is a recreation of that dial (minus the diamonds and other precious stones).

In 1777, when the French general Lafayette wanted to express his respect and admiration for his ally and friend General George Washington during the American revolution, he chose as his gift a silver Explorer dial.

By the 18th century, clocks and watches began to supersede sundials. They had one big advantage - they were not subject to the whims of clear skies. But they were often unreliable, and depended on sundials to set the true time.

That leads to the next big issue - what is the true or exact time. Because of the earth's rotation, the town 20 or 30 miles East or West would have its clock set slightly differently. Your noon arrived somewhat before that of your Western neighbor but sometime after that of your Eastern one.

THE SPREAD OF
THE RAILROAD IN
THE 19TH CENTURY
LED TO THE
CREATION OF
STANDARD TIME
ZONES.

This was of little consequence to the residents who might never in their lives venture to either of those neighboring towns. What matter if their clocks were five or ten minutes different? By the late 19th Century time discrepancies began to matter. The reason? The railroads: they demanded schedules. Schedules demanded times; but whose time? Along a hundred mile stretch there might be 6 different cities with 6 different town clocks all different from the other. Passengers needed to know what time the train would depart and when it would reach its destination. Railroaders needed to know when to send the next train and avoid serious accidents.

In 1884, a conference was held and an agreement was reached to divide the USA up into 4 zones each 15 degrees wide - Eastern, Central, Mountain and Pacific, and all stations in the zone would carry the same time. In fact, train time which was quite rigorously held to by the railroads became the time that cities and citizens set their clocks by. The train whistle became the signal for setting clocks.