Humans were always interested in determining time. Therefore the first clocks were invented in ancient times. But unlike today’s clocks they were not mechanical or electrical. The so called sundials were used by the Romans, the Greeks, the Egyptians and other cultures. Artifacts of sundials were found all over the globe. The length of the shadow cast by the sun was used to determine time.
In 9 BC Emperor Augustus built a giant sundial, which was made of a 30 m high Egyptian obelisk. The scale was almost 200m in diameter. Other examples of sundials from ancient times were found in houses in Pompeii, which were preserved by the lava of the volcano. Portable watches were also known in ancient Rome and Egypt. In the first century BC, such viatoriapensilia were described by the Roman engineer Vitruvius. These sundials were carried along on trips and hung on strings or rings to tell the time.
Sundials of this kind were in use until the second half of the Mid Ages. Then, more accurate sundials were invented. In the 16th century linen-based sundials were built in Nuremberg and Augsburg. Many engineers, inventors and writers dedicated some of their work on sundials. Therefore some papers and books about building sundials still exist and engineers all over the world are still fascinated by the accuracy with which these sundials work. The sundials of this time had a built-in compass to make setting it in the right position easier.
Even more accurate sundials were built in the 17th century. The hollow sundials displayed at least two surfaces at the same time. As a result a compass was not needed anymore. In this century sundials made of bronze, silver and ivory were very popular. But still, people were only able to tell the time at the exact moment they were looking at the sundial. When time zones were introduced sundials lost their meaning to society and new kinds of watches were invented. Mechanical watches could be set to different times and were therefore much more practical than sundials. Today nobody is carrying around a sundial anymore. The requirements simply changed.July 12th, 2011
Topic: History Tags: None