The history of clocks is vast and dates back to centuries with an evolution of a variety of clocks. Not all historians agree on the history of the clock. The word clock was first used in the 14th century (about 700 years ago). It comes from the word for bell in Latin (“clocca”).

Usage of Sun
The very first method that people used to know the time was by looking at the sun as it moves across the skyline. When the sun was directly overhead in the sky, people considered it as the middle of the day. When the sun was near to the horizon, it was either early morning known as sunrise or evening known as sunset. Presuming time was not very accurate during these days.

Sundial Clocks
The oldest type of clock is a sundial clock, well known as sun clocks. They were first used around 3,500 B.C. (about 5,500 years ago). Sundials use the sun to tell the time. The shadow of the sun points to a number on a circular disk that shows you the time. As sundials depend on the sun, these clocks had a very limited use during day time and during sunny days of the year.

Water Clocks
Around 1400 B.C. (about 3,400 years ago), water clocks were invented in Egypt. The name for a water clock is clepsydra (pronounced KLEP-suh-druh). Water clocks were famous in Greece, where they were further improved many times over the period of time. Water clocks could perform better than sundials as people could easily use it during night and all thought the year.

Pendulum Clocks
The pendulum swings left and right, and as it swings, it turns a wheel with teeth. The turning wheel turns the hour and minute hands on the clock. At first pendulum clocks, the pendulum used to have a wide angle. As it improved with time, it underwent many changes and the angle of pendulum was narrowed.
The first pendulum clock with external batteries was developed around 1840. By 1906, the batteries were inside the clock.