The Alarm Clock

Oh, the most of us just hate Alarm clock! But also sometimes they simply rescue our life. And did you know that everything started in ancient Greece? It was actually the idea of Platon - the famous, ancient Greek philosopher. Based on the water clock, which already existed, Platon constructed a prototype of  the alarm clock. He used the hourglass, on which water pressured on the closed part of this tool. This was making the sound out, because of the air which was inside. Sounds very simple, but before this idea nobody thought about that. He used it probably to remind about his lectures, to signalise that it will start soon.

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