Over the centuries, people have developed various ways of telling the time. First, about 5,500 years ago, the sun clock was invented by the Egyptians. Next, about 3,500 years ago, the Egyptians made a sundial. Then, the water clocks were used by the Egyptians about 3,400 years ago. After that, in the thirteenth century, the power-driven clock was invented. In 1927, the firstly quartz clock was developed. Lately, more recently, in 1956, came the digital clock.