Sundial – Ancient Time Keeping

A sundial is an instrument that tells the time like a clock. It has a pole or gnomon in its center and markings that show hours or fraction of hours. It works on the concept of the sun changing its location in the sky throughout the day.

When the sun shines on gnomon, it casts shadows that appear on different markings on the sundial. This instrument is in use since ancient times and was the main indicator of time until the early 19th century. This is still not known exactly who invented the sundial. It is also one of the oldest scientific instruments of the world.


Quick Facts: –

  • This instrument depends on the rotation and movement of the Sun from east to west.
  • There are two main types of sundials. The first one is the altitude dial and the other one is the azimuth dial.
  • People first learned about time by watching the sun rise and set and developed a way to tell time on the basis of sunrise and sunset.
  • The ancient contraption was first created by the Babylonian and Egyptian civilizations and works by measuring the Sun’s movement across the sky.
  • The Egyptians built a t-shaped sundial comprising of a crossbar and a vertical stick. On the stick, five hours were written.
  • The first sundial in Rome was captured from the Samnites.
  • The sundials need to point north and sit on a flat surface and the gnomon casts a shadow.
  • The sun is highest in the sky at midday and casts short shadows. Longer shadows are casted when sun is lower in the sky.
  • The largest sundial in the world was constructed in 1724 in Jaipur, India. It covers almost one acre in size.